Natural Water Natural Water DisastersDisastersMicrobiology Microbiology

andandDiseaseDisease

Kelley E. Capocelli, MDKelley E. Capocelli, MDOctober 28, 2005October 28, 2005

THIS HAS BEEN THIS HAS BEEN A RECORD YEAR A RECORD YEAR

FOR WATER FOR WATER DISASTERSDISASTERS

HURRICANE HURRICANE KATRINAKATRINA

HURRICANE HURRICANE RITARITA

AND IF THAT AND IF THAT WASN’T WASN’T

ENOUGH…ENOUGH…

HURRICANE HURRICANE WILMA WILMA COMES COMES ALONGALONG

Infectious Disease Infectious Disease after Natural Water after Natural Water

DisasterDisaster• Flooding is associated with an Flooding is associated with an

increased risk of infection, however increased risk of infection, however this risk is low unless there is this risk is low unless there is significant population displacement significant population displacement and/or water sources are and/or water sources are compromisedcompromised– The major risk factor for outbreaks The major risk factor for outbreaks

associated with flooding is the associated with flooding is the contamination of drinking-water contamination of drinking-water facilitiesfacilities

Infectious Disease Infectious Disease after Natural Water after Natural Water

DisasterDisaster• Infectious disease outbreaks are rare Infectious disease outbreaks are rare

following natural disasters, especially in following natural disasters, especially in developed countriesdeveloped countries– Specific etiologies are usually predictable, Specific etiologies are usually predictable,

reflecting infectious diseases endemic to the reflecting infectious diseases endemic to the affected region before the disasteraffected region before the disaster

– Injury and soft tissue infections are expected Injury and soft tissue infections are expected during the first few days after a disasterduring the first few days after a disaster

– In contrast, airborne, waterborne, and In contrast, airborne, waterborne, and foodborne diarrheal illness that is easily spread foodborne diarrheal illness that is easily spread in densely populated communities can be in densely populated communities can be anticipated after a natural disasteranticipated after a natural disaster

Infectious Disease Infectious Disease After HurricaneAfter Hurricane

•Health IssuesHealth Issues

– Waterborne illnessesWaterborne illnesses– Vectorborne illnessesVectorborne illnesses– Skin infectionsSkin infections– Airborne illnessesAirborne illnesses– Mold/MildewMold/Mildew– Human RemainsHuman Remains

Waterborne Waterborne DiseasesDiseases

• Common waterborne diseases in the Common waterborne diseases in the United States include:United States include:– AmebiasisAmebiasis– CampylobacteriosisCampylobacteriosis– CryptosporidiosisCryptosporidiosis– GiardiasisGiardiasis– Hepatitis AHepatitis A– SalmonellosisSalmonellosis– ShigellosisShigellosis– Viral gastroenteritisViral gastroenteritis

AmebiasisAmebiasis• Caused by Caused by Entamoeba histolyticaEntamoeba histolytica

– Disease is expressed most often as ulcerative Disease is expressed most often as ulcerative and inflammatory lesions of the colon resulting and inflammatory lesions of the colon resulting in a complete spectrum of colonic signs and in a complete spectrum of colonic signs and symptomssymptoms• Occasionally, amebas gain access to extraintestinal Occasionally, amebas gain access to extraintestinal

sites, most commonly the liver, where marked tissue sites, most commonly the liver, where marked tissue destruction occursdestruction occurs

– Risk factors that predispose to infectionRisk factors that predispose to infection• CrowdingCrowding

• No indoor plumbingNo indoor plumbing

• Persons living communallyPersons living communally

AmebiasisAmebiasis• Amebiasis (cont.)Amebiasis (cont.)

– Factors attributing to increased severity of Factors attributing to increased severity of diseasedisease• Children (esp. neonates)Children (esp. neonates)• PregnancyPregnancy• Corticosteroid useCorticosteroid use• MalignancyMalignancy• MalnutritionMalnutrition

• Organism morphologyOrganism morphology– Trophozoites range in size from 10 to 60 Trophozoites range in size from 10 to 60 µµmm

• Have a single 3- to 5-Have a single 3- to 5-µµm nucleus containing fine m nucleus containing fine peripheral chromatin and a central nucleolusperipheral chromatin and a central nucleolus

• Often have ingested erythrocytesOften have ingested erythrocytes– Cysts average 12 Cysts average 12 µµm in diameter and contain m in diameter and contain

one to four nuclei with morphology identical to one to four nuclei with morphology identical to that of trophozoite nucleithat of trophozoite nuclei

CampylobacteriosisCampylobacteriosis

• Among the most common bacterial Among the most common bacterial infections of humans in all parts of the infections of humans in all parts of the world, campylobacters cause both world, campylobacters cause both diarrheal and systemic illnessesdiarrheal and systemic illnesses– Excreta from infected animals may Excreta from infected animals may

contaminate soil or watercontaminate soil or water•Untreated surface water has been responsible Untreated surface water has been responsible

for both endemic and epidemic for both endemic and epidemic campylobacteriosiscampylobacteriosis

• Motile, non-spore forming, comma-Motile, non-spore forming, comma-shaped, gram-negative rodsshaped, gram-negative rods

CryptosporidiosisCryptosporidiosis

• A diarrheal disease caused by microscopic A diarrheal disease caused by microscopic parasites of the genus parasites of the genus CryptosporidiumCryptosporidium– Cryptosporidium parvumCryptosporidium parvum and and Cryptosporidium Cryptosporidium

hominishominis are the most common disease causing are the most common disease causing speciesspecies

– Once an animal or person is infected, the Once an animal or person is infected, the parasite lives in the intestine and passes in the parasite lives in the intestine and passes in the stoolstool• Millions of crypto organisms can be released in a bowel Millions of crypto organisms can be released in a bowel

movement from an infected human or animalmovement from an infected human or animal

• The parasite is protected by an outer shell that allows it The parasite is protected by an outer shell that allows it to survive outside the body for long periods of time and to survive outside the body for long periods of time and makes it very resistant to chlorine-based disinfectantsmakes it very resistant to chlorine-based disinfectants

CryptosporidiosisCryptosporidiosis

• Life cycleLife cycle– Sporulated oocysts, containing 4 Sporulated oocysts, containing 4

sporozoites, are excreted by the sporozoites, are excreted by the infected host through feces and possibly infected host through feces and possibly through other routes, such as through other routes, such as respiratory secretionsrespiratory secretions

– Following ingestion by a suitable host, Following ingestion by a suitable host, excystation occursexcystation occurs

CryptosporidiosisCryptosporidiosis

• Life cycle (cont.)Life cycle (cont.)– The sporozoites are released and parasitize The sporozoites are released and parasitize

epithelial cells of the GI or respiratory tractepithelial cells of the GI or respiratory tract•Undergo both asexual and sexual multiplicationUndergo both asexual and sexual multiplication

– Two oocysts are producedTwo oocysts are produced Thick-walled – commonly excreted from the hostThick-walled – commonly excreted from the host Thin-walled – involved in autoinfectionThin-walled – involved in autoinfection

• Sites of infectionSites of infection– Small intestine, most commonlySmall intestine, most commonly– Other digestive tract organs, the lungs, and Other digestive tract organs, the lungs, and

the conjunctivathe conjunctiva

GiardiasisGiardiasis

• Diarrheal illness caused by a one-Diarrheal illness caused by a one-celled, microscopic parasite, celled, microscopic parasite, Giardia Giardia intestinalisintestinalis– A protozoan flagellate (Diplomonadida)A protozoan flagellate (Diplomonadida)

• Worldwide distribution Worldwide distribution – Infection occurs by the ingestion of cysts Infection occurs by the ingestion of cysts

in contaminated water, food, or by fecal-in contaminated water, food, or by fecal-oral routeoral route

– The cysts are hardy and can survive The cysts are hardy and can survive several months in cold waterseveral months in cold water

GiardiasisGiardiasis

• Life cycleLife cycle– In the small intestine, encystation releases In the small intestine, encystation releases

trophozoites (each cyst produces two trophozoites (each cyst produces two trophozoites)trophozoites)

– Trophozoites multiply by longitudinal binary Trophozoites multiply by longitudinal binary fission, remaining in the lumen of the proximal fission, remaining in the lumen of the proximal small bowel where they can be free or small bowel where they can be free or attached to the mucosa by a ventral sucking attached to the mucosa by a ventral sucking diskdisk

– Encystation occurs as the parasites transit Encystation occurs as the parasites transit toward the colontoward the colon• The cyst is the stage found most commonly in The cyst is the stage found most commonly in

nondiarrheal fecesnondiarrheal feces

Hepatitis AHepatitis A

• Small, unenveloped symmetrical RNA Small, unenveloped symmetrical RNA virus virus – The cause of infectious or epidemic The cause of infectious or epidemic

hepatitis transmitted by the fecal-oral routehepatitis transmitted by the fecal-oral route•Person to person the most common routePerson to person the most common route•Quickly spread through close contact, Quickly spread through close contact,

particularly within families and institutionsparticularly within families and institutions•Food and water borne outbreaks also occur Food and water borne outbreaks also occur

frequently and although almost any food can be frequently and although almost any food can be implicated the most common sources are: implicated the most common sources are:

– Shellfish eaten raw or poorly cooked from sewage-Shellfish eaten raw or poorly cooked from sewage-polluted water. polluted water.

– Foods handled without sufficient hygiene and not Foods handled without sufficient hygiene and not cooked subsequently. cooked subsequently.

SalmonellosisSalmonellosis• Salmonella typhimuriumSalmonella typhimurium and and Salmonella enteritidisSalmonella enteritidis

are the most common types in the United Statesare the most common types in the United States– Usually associated with diarrheal disease, rarely Usually associated with diarrheal disease, rarely

associated with bacteremia, endocarditis, and wound associated with bacteremia, endocarditis, and wound infectionsinfections

• Gram negative, non-spore forming, facultatively Gram negative, non-spore forming, facultatively aerobic bacilli 2 to 3 by 0.4 to 0.6 aerobic bacilli 2 to 3 by 0.4 to 0.6 µµm in sizem in size

• Most often, acquisition of organisms occurs by Most often, acquisition of organisms occurs by ingestion of food or water contaminated with ingestion of food or water contaminated with human excretahuman excreta

• Usually, waterborne transmission involves the Usually, waterborne transmission involves the ingestion of fewer microorganisms and, as a result, ingestion of fewer microorganisms and, as a result, has a longer incubation period and lower attack has a longer incubation period and lower attack rate than foodborne transmissionrate than foodborne transmission

ShigellosisShigellosis

• In the United States, over two thirds of In the United States, over two thirds of shigellosis cases are caused by shigellosis cases are caused by Shigella Shigella sonneisonnei, and , and Shigella flexneriShigella flexneri causes most of causes most of the remaining casesthe remaining cases– Outbreaks of shigellosis in the U.S. are typically Outbreaks of shigellosis in the U.S. are typically

caused by caused by S. sonnei S. sonnei and occur in crowded and occur in crowded settingssettings• Personal hygiene limitedPersonal hygiene limited

• Contaminated food and waterContaminated food and water

– Fecal-oral transmission causing diarrhea (often Fecal-oral transmission causing diarrhea (often bloody), fever, and stomach crampsbloody), fever, and stomach cramps

– Gram negative rod, non-lactose fermenterGram negative rod, non-lactose fermenter

Escherichia coliEscherichia coli• Infection spreads to people through Infection spreads to people through

contact with human or animal fecescontact with human or animal feces• Contaminated water or food or through person-to-Contaminated water or food or through person-to-

person contactperson contact

• Usually associated with self-limited diarrheaUsually associated with self-limited diarrhea

• Eschericia coliEschericia coli bacteria, not O157:H7, were bacteria, not O157:H7, were measured in flood waters after Hurricane measured in flood waters after Hurricane KatrinaKatrina

• these “generic” these “generic” E. coliE. coli are normally found in all are normally found in all streams, lakes, and canalsstreams, lakes, and canals

– When there is flooding along with a hurricane, the When there is flooding along with a hurricane, the waters may contain fecal material from overflowing waters may contain fecal material from overflowing sewage systems and agricultural and industrial wastesewage systems and agricultural and industrial waste

Viral GastroenteritisViral Gastroenteritis• EnterovirusEnterovirus

– RNA virusRNA virus• can be found respiratory secretions and stoolcan be found respiratory secretions and stool

• Norovirus (Caliciviridae)Norovirus (Caliciviridae)– A group of viruses that cause gastroenteritisA group of viruses that cause gastroenteritis

• Nonenveloped RNA virusNonenveloped RNA virus– Small round structured virusesSmall round structured viruses

• Waterborne outbreaks have been caused by sewage Waterborne outbreaks have been caused by sewage contamination of wells and recreational watercontamination of wells and recreational water

• Also associated with food poisoning due to fecal-oral Also associated with food poisoning due to fecal-oral transmissiontransmission

• RotavirusRotavirus– More commonly in infants and young childrenMore commonly in infants and young children

• Fecal-oral transmissionFecal-oral transmission

Documented Documented InfectionInfection

• GastroenteritisGastroenteritis– CDC received reports of clusters of diarrheal CDC received reports of clusters of diarrheal

disease among persons in evacuation centers disease among persons in evacuation centers in Louisiana, Mississippi, Tennessee, and Texasin Louisiana, Mississippi, Tennessee, and Texas• Have diagnosed norovirus, nontyphoidal Salmonella, Have diagnosed norovirus, nontyphoidal Salmonella,

nontoxigenic V. cholerae O1nontoxigenic V. cholerae O1– More than 1,000 people were treated for diarrhea, More than 1,000 people were treated for diarrhea,

vomiting, or both symptoms between September 2 and vomiting, or both symptoms between September 2 and September 12, 2005, according to the CDCSeptember 12, 2005, according to the CDC

• No confirmed cases of Shigella dysentery, typhoid No confirmed cases of Shigella dysentery, typhoid fever, or infection by toxigenic V. cholerae O1fever, or infection by toxigenic V. cholerae O1

• Large dilution factor in the flood water—not enough Large dilution factor in the flood water—not enough pathogens to cause diseasepathogens to cause disease

Documented Documented InfectionInfection

• Conditions that facilitate virus Conditions that facilitate virus transmissiontransmission– CrowdingCrowding– Insufficient sanitation in lavatoriesInsufficient sanitation in lavatories– Lack of adequate number of hand-Lack of adequate number of hand-

washing facilitieswashing facilities– Delays in cleaning and decontaminating Delays in cleaning and decontaminating

soiled areas and beddingsoiled areas and bedding

VibrioVibrio Infections Infections• Vibrio parahaemolyticusVibrio parahaemolyticus

– Primarily causes gastrointestinal illness (rarely Primarily causes gastrointestinal illness (rarely wound infections)wound infections)• About half of cases reported to CDC every yearAbout half of cases reported to CDC every year

– The most common The most common VibrioVibrio species isolated from humans species isolated from humans

– Most people become infected by eating raw or Most people become infected by eating raw or undercooked shellfish, particularly oysters, or undercooked shellfish, particularly oysters, or other food contaminated by raw shellfishother food contaminated by raw shellfish

• Vibrio vulnificus Vibrio vulnificus is a bacterium that is a is a bacterium that is a rare cause of illness in the United Statesrare cause of illness in the United States– Persons who develop wound infections do so Persons who develop wound infections do so

following contamination of a pre-existing following contamination of a pre-existing wound or through an injury acquired while wound or through an injury acquired while exposed to warm coastal watersexposed to warm coastal waters

VibrioVibrio Infections Infections

• Vibrio choleraeVibrio cholerae– Have a natural reservoir in sea and coastal Have a natural reservoir in sea and coastal

waterswaters– In an epidemic, the source of contamination is In an epidemic, the source of contamination is

usually the feces of an infected personusually the feces of an infected person• The disease can spread rapidly in areas with The disease can spread rapidly in areas with

inadequate treatment of sewage and drinking waterinadequate treatment of sewage and drinking water– Associated with serogroup O1 (toxin-producing) and Associated with serogroup O1 (toxin-producing) and

non-O1 (in the United States)non-O1 (in the United States)

• If there is a clinical suspicion of If there is a clinical suspicion of infection with infection with VibrioVibrio, use of a selective , use of a selective media thiosulfate-citrate-bile salts-media thiosulfate-citrate-bile salts-sucrose (TCBS) is recommendedsucrose (TCBS) is recommended

VibrioVibrio Infections Infections

• Vibrio choleraeVibrio cholerae (cont.) (cont.)– GastroenteritisGastroenteritis

•Non-O1 = mild to severe watery diarrheaNon-O1 = mild to severe watery diarrhea

•O1 = fever and bloody diarrheaO1 = fever and bloody diarrhea

– SepsisSepsis•Non-O1 = in immunocompromised people Non-O1 = in immunocompromised people

and in people with liver diseaseand in people with liver disease

– Wound infectionsWound infections•Non-O1 = rarelyNon-O1 = rarely

VibrioVibrio Infections Infections

• During August 29-September 11, 2005, During August 29-September 11, 2005, surveillance identified 22 new cases of surveillance identified 22 new cases of VibrioVibrio with five deaths with five deaths– Caused by Caused by V. vulnificusV. vulnificus, , V. parahemolyticusV. parahemolyticus, ,

and nontoxigenic and nontoxigenic V. choleraeV. cholerae– Eighteen wound-associated Eighteen wound-associated VibrioVibrio cases were cases were

reportedreported• Mississippi = 7Mississippi = 7• Louisiana = 5Louisiana = 5• Texas = 2 (from Louisiana)Texas = 2 (from Louisiana)• Arkansas = 2 (from Louisiana)Arkansas = 2 (from Louisiana)• Arizona = 1 (from Louisiana)Arizona = 1 (from Louisiana)• Florida = 1 (from Mississippi)Florida = 1 (from Mississippi)

VibrioVibrio Infections Infections

• Non-wound associated illnessesNon-wound associated illnesses– Four persons were reported with non-Four persons were reported with non-

wound associated wound associated VibrioVibrio infections infections•Mississippi = 2Mississippi = 2

– Nontoxigenic Nontoxigenic V. choleraeV. cholerae gastroenteritis (non O1 gastroenteritis (non O1 subtype) subtype)

Two month old boy and an adult Two month old boy and an adult

•Louisiana = 1Louisiana = 1

•Arizona (from Louisiana) = 1Arizona (from Louisiana) = 1

VibrioVibrio Infections Infections• SpeciationSpeciation

– V. vulnificus V. vulnificus = 14= 14– V. parahemolyticusV. parahemolyticus = 4 = 4

• DeathsDeaths– V. vulnificus V. vulnificus = 3= 3– V. parahemolyticus V. parahemolyticus = 2 = 2

• An underlying condition that might have increased risk for An underlying condition that might have increased risk for severe severe VibrioVibrio illness was reported in 13 of the patients with illness was reported in 13 of the patients with woundswounds

– Heart disease = 7Heart disease = 7– Diabetes mellitus = 4Diabetes mellitus = 4– Renal disease = 3Renal disease = 3– Alcoholism = 3Alcoholism = 3– Liver disease = 2Liver disease = 2– Peptic ulcer disease = 1Peptic ulcer disease = 1– Immunodeficiency = 1Immunodeficiency = 1– Malignancy = 1Malignancy = 1

LeptospirosisLeptospirosis• Leptospirosis—a zoonotic bacterial diseaseLeptospirosis—a zoonotic bacterial disease

– Caused by the bacteria Caused by the bacteria LeptospiraLeptospira• a flexible, spiral-shaped, Gram-negative spirochete a flexible, spiral-shaped, Gram-negative spirochete

with internal flagella with internal flagella

• Leptospirosis is a worldwide zoonosis Leptospirosis is a worldwide zoonosis affecting many wild and domestic animalsaffecting many wild and domestic animals– Humans acquire the infection by contact with Humans acquire the infection by contact with

the urine of infected animalsthe urine of infected animals– Human-to-human transmission is extremely Human-to-human transmission is extremely

rarerare• Between 1965 and 1993, the incidence Between 1965 and 1993, the incidence

rate of leptospirosis in Louisiana ranged rate of leptospirosis in Louisiana ranged from 1 to 14 per 100,000 people per yearfrom 1 to 14 per 100,000 people per year– Outbreaks of leptospirosis have occurred Outbreaks of leptospirosis have occurred

following flood eventsfollowing flood events

LeptospirosisLeptospirosis

• Clinical presentationClinical presentation– Wide variety of clinical manifestations, Wide variety of clinical manifestations,

ranging from a mild flu-like illness to a ranging from a mild flu-like illness to a serious and sometimes fatal diseaseserious and sometimes fatal disease•May occur in two phasesMay occur in two phases

– Phase 1 – fever, chills, severe headache, muscle Phase 1 – fever, chills, severe headache, muscle aches, vomiting, or diarrheaaches, vomiting, or diarrhea

Also jaundice, abdominal pain, or a rashAlso jaundice, abdominal pain, or a rash Patient may recover for a time but become ill Patient may recover for a time but become ill

againagain– Phase 2 – Weil’s syndromePhase 2 – Weil’s syndrome

Jaundice, renal failure, hemorrhage, and Jaundice, renal failure, hemorrhage, and myocarditis with arrhythmiasmyocarditis with arrhythmias

LeptospirosisLeptospirosis• Clinical criteria for leptospirosis:

1. Fever > 38.0°C (100.4°F)2. AND at least TWO from COLUMN A or ONE

from COLUMN B

COLUMN A COLUMN BHeadache Aseptic meningitisMyalgias Acute renal failureJaundice Hemorrhagic pneumonitisChills/Rigors Cardiac arrhythmias, EKG

abnormalitiesSkin rash Liver failureConjunctival suffusion withoutJaundice with acute renal failurepurulent discharge

Vector-borne Vector-borne IllnessesIllnesses

• Floods may indirectly lead to an increase in Floods may indirectly lead to an increase in vector-borne diseases through the expansion vector-borne diseases through the expansion in the number and range of vector habitatsin the number and range of vector habitats– Standing water caused by heavy rainfall or Standing water caused by heavy rainfall or

overflow of rivers/oceans can act as breeding sites overflow of rivers/oceans can act as breeding sites for mosquitoesfor mosquitoes• Enhance the potential for exposure of the disaster-Enhance the potential for exposure of the disaster-

affected population and emergency workers to infections affected population and emergency workers to infections such as dengue, malaria, and West Nile feversuch as dengue, malaria, and West Nile fever

• Flooding may initially flush out mosquito breeding but it Flooding may initially flush out mosquito breeding but it comes back when the waters recede—lag time is usually comes back when the waters recede—lag time is usually around 6-8 weeks before the onset of a malaria epidemicaround 6-8 weeks before the onset of a malaria epidemic

West Nile VirusWest Nile Virus

• A single-stranded RNA virus of the family A single-stranded RNA virus of the family Flaviviridae, genus FlavivirusFlaviviridae, genus Flavivirus– Flaviviruses share a common size (40-60 nm), Flaviviruses share a common size (40-60 nm),

symmetry (enveloped, icosahedral symmetry (enveloped, icosahedral nucleocapsid), nucleic acid (positive-sense, nucleocapsid), nucleic acid (positive-sense, single stranded RNA approximately 10,000-single stranded RNA approximately 10,000-11,000 bases), and appearance in the electron 11,000 bases), and appearance in the electron microscope. microscope.

• WNV is a member of the Japanese WNV is a member of the Japanese encephalitis virus antigenic complexencephalitis virus antigenic complex– includes Japanese encephalitis, St. Louis includes Japanese encephalitis, St. Louis

encephalitis, Murray Valley encephalitis, and encephalitis, Murray Valley encephalitis, and Kunjin, an Australian subtype of WNV. Kunjin, an Australian subtype of WNV.

West Nile VirusWest Nile Virus

• West Nile Virus (cont.)West Nile Virus (cont.)– Hurricanes brought no increase in West Hurricanes brought no increase in West

Nile casesNile cases•The storm blew away most of the The storm blew away most of the

established mosquito populationestablished mosquito population– Predicted that survivors will soon repopulate the Predicted that survivors will soon repopulate the

area and old eggs now submerged in water will area and old eggs now submerged in water will hatch and pupate quicklyhatch and pupate quickly

– The increase in the insect population will bring The increase in the insect population will bring back many bird species probably including those back many bird species probably including those carrying West Nile and St. Louis encephalitis. carrying West Nile and St. Louis encephalitis.

West Nile VirusWest Nile Virus

• Documented West Nile InfectionDocumented West Nile Infection– Thirty cases reported in Louisiana in the Thirty cases reported in Louisiana in the

second week of October 2005second week of October 2005•Approximately the same number of cases as Approximately the same number of cases as

in 2004in 2004– Louisiana 2005 = 129 West Nile cases, 6 deathsLouisiana 2005 = 129 West Nile cases, 6 deaths– Louisiana 2004 = 114 West Nile cases, 7 deathsLouisiana 2004 = 114 West Nile cases, 7 deaths– Mississippi 2005 = 60 West Nile cases, 4 deathsMississippi 2005 = 60 West Nile cases, 4 deaths

– Post-hurricane cases mostly occurred in Post-hurricane cases mostly occurred in the Baton Rouge area and the north the Baton Rouge area and the north shore area of Lake Pontchartrain, where shore area of Lake Pontchartrain, where the virus was heavily present before the the virus was heavily present before the hurricaneshurricanes

Skin InfectionsSkin Infections

• Methicillin Resistant Methicillin Resistant Staphylococcus aureusStaphylococcus aureus– September 26, 2005 (MMWR Dispatch)September 26, 2005 (MMWR Dispatch)

• 30 pediatric and adult patients at an evacuee facility in 30 pediatric and adult patients at an evacuee facility in Dallas, TexasDallas, Texas

– Majority were skin infections, including pimples and boilsMajority were skin infections, including pimples and boils– Three cases confirmed with cultureThree cases confirmed with culture

• Tinea corporisTinea corporis– Military personnel from two locations working in Military personnel from two locations working in

the wet environment of early evacuation effortsthe wet environment of early evacuation efforts• FolliculitisFolliculitis

– Erythematous, papular, and pustular lesions Erythematous, papular, and pustular lesions among military personnel in Mississippiamong military personnel in Mississippi

Airborne IllnessesAirborne Illnesses• Upper respiratory infections and Upper respiratory infections and

pneumoniaspneumonias– Pertussis in a 2-month old infant who was Pertussis in a 2-month old infant who was

rescued from a rooftop in New Orleans and rescued from a rooftop in New Orleans and evacuated to Tennesseeevacuated to Tennessee

• TuberculosisTuberculosis– A homeless person without a diagnosis of TB A homeless person without a diagnosis of TB

who was evacuated from New Orleans to who was evacuated from New Orleans to PhiladelphiaPhiladelphia

– Eight other patients initially identified as having Eight other patients initially identified as having TB were subsequently determined to have TB were subsequently determined to have other conditionsother conditions• Lung cancerLung cancer• Nontuberculous mycobacteria (including one with Nontuberculous mycobacteria (including one with

MAC from Denver Health)MAC from Denver Health)

Airborne IllnessesAirborne Illnesses

• Known TB patientsKnown TB patients– A total of 195 persons known by the A total of 195 persons known by the

public health authorities in Alabama, public health authorities in Alabama, Mississippi, and Louisiana to be Mississippi, and Louisiana to be undergoing treatment for TB undergoing treatment for TB •Sought out by TB program staff to assure Sought out by TB program staff to assure

that therapy continuedthat therapy continued– 42 TB patients from Louisiana not yet located42 TB patients from Louisiana not yet located

41 assumed to be noncontagious at the time 41 assumed to be noncontagious at the time the hurricane made landfallthe hurricane made landfall

Decision based on disease site, treatment Decision based on disease site, treatment duration, or smear statusduration, or smear status

Legionnaires’ Legionnaires’ DiseaseDisease

• Caused by Caused by LegionellaLegionella bacteria bacteria– Thrive in stagnant, warm waterThrive in stagnant, warm water

• Favor a temperature of 25-42 C (77-108 F) for growthFavor a temperature of 25-42 C (77-108 F) for growth

• Outbreaks of this disease have been Outbreaks of this disease have been associated with cooling towers, evaporative associated with cooling towers, evaporative condensers, showers, faucets, hot condensers, showers, faucets, hot tubs/whirlpool spas, and other sources of tubs/whirlpool spas, and other sources of aerosolized wateraerosolized water– Because many buildings and cooling towers Because many buildings and cooling towers

were shut down during hurricanes Katrina and were shut down during hurricanes Katrina and Rita, the water in those systems has been sitting Rita, the water in those systems has been sitting stagnant for days to weeks, providing an stagnant for days to weeks, providing an increased risk of Legionnaires’ disease once the increased risk of Legionnaires’ disease once the systems are restartedsystems are restarted

Legionnaires’ Legionnaires’ DiseaseDisease

• Legionnaires’ disease is contracted Legionnaires’ disease is contracted when people breathe in mist or vapor when people breathe in mist or vapor that has been contaminated with the that has been contaminated with the bacteriabacteria– The bacteria are NOT spread from The bacteria are NOT spread from

person to personperson to person•Causes death in up to 30% of casesCauses death in up to 30% of cases

Mold/MildewMold/Mildew

• Health Effects of MoldHealth Effects of Mold– InfectionInfection

•Particularly in people with suppressed Particularly in people with suppressed immune systemsimmune systems

– AllergyAllergy•FeverFever

•Skin rashSkin rash

•Exacerbation of respiratory illnessesExacerbation of respiratory illnesses

– Toxin-mediated diseaseToxin-mediated disease

Mold/MildewMold/Mildew• Molds are multicellular and are composed Molds are multicellular and are composed

of filamentous structures called hyphaeof filamentous structures called hyphae– Hyphae are approximately 5-50 Hyphae are approximately 5-50 µm long and 2-µm long and 2-

4 µm in diameter4 µm in diameter– In most molds, hyphae are divided into distinct, In most molds, hyphae are divided into distinct,

cell-like units by crosswalls termed septacell-like units by crosswalls termed septa• Hyphae that contain septa are called septateHyphae that contain septa are called septate

– When growing in nature and in culture in the When growing in nature and in culture in the laboratory, hyphae typically branch and laboratory, hyphae typically branch and intertwine, forming a compact mass called a intertwine, forming a compact mass called a mycelium, which constitutes the mold colonymycelium, which constitutes the mold colony

Mold/MildewMold/Mildew

• In medical mycology, the term dimorphism is In medical mycology, the term dimorphism is limited to pathogenic fungi that exist as molds at limited to pathogenic fungi that exist as molds at room temperature and convert to a yeast phase room temperature and convert to a yeast phase at 35at 35° or 37°C° or 37°C– These organisms are true or primary pathogens and These organisms are true or primary pathogens and

include the causative agents of serious, systemic include the causative agents of serious, systemic infections that are often fatalinfections that are often fatal

• Blastomyces dermatitidisBlastomyces dermatitidis• Histoplasma capsulatumHistoplasma capsulatum• Paracoccidiodes brasilensisParacoccidiodes brasilensis• Sporothrix schenskiiSporothrix schenskii• Coccidiodes immitisCoccidiodes immitis

--differs in that in tissues or when grown at 37°C on --differs in that in tissues or when grown at 37°C on special media, it special media, it produces spherules instead of growing as a yeastproduces spherules instead of growing as a yeast

BlastomycosisBlastomycosis

• Most likely primary systemic mycosis Most likely primary systemic mycosis infection in Southeastern coastal infection in Southeastern coastal states after hurricanestates after hurricane– BlastomycosisBlastomycosis

•Causative agent = Causative agent = Blastomyces dermatitidisBlastomyces dermatitidis•Habitat = unknownHabitat = unknown

– Outbreaks have been associated around streams Outbreaks have been associated around streams or rivers with high content of moist soil enriched or rivers with high content of moist soil enriched with organic debris and/or rotting woodwith organic debris and/or rotting wood

•Geographic distribution Geographic distribution – Mid-western and southeastern regions of North Mid-western and southeastern regions of North

America, Central America and South America, and America, Central America and South America, and parts of Africaparts of Africa

BlastomycosisBlastomycosis

• Blastomycosis (cont.)Blastomycosis (cont.)– The infection is acquired via inhalation The infection is acquired via inhalation

of the conidia, which transform into the of the conidia, which transform into the yeast form once in the lungsyeast form once in the lungs•After 30 to 45 days an acute pulmonary After 30 to 45 days an acute pulmonary

disease indistinguishable from a bacterial disease indistinguishable from a bacterial pneumonia may occurpneumonia may occur

•Most cases become manifest during a Most cases become manifest during a chronic and indolent phase that may affect chronic and indolent phase that may affect the lungs, the skin, the bones, the the lungs, the skin, the bones, the genitourinary tract and other genitourinary tract and other reticuloendothelial organsreticuloendothelial organs

BlastomycosisBlastomycosis

• Forms of blastomycosisForms of blastomycosis– Acute pulmonaryAcute pulmonary

• Lobar or segmental consolidation Lobar or segmental consolidation

– Chronic pulmonaryChronic pulmonary• Lobar infiltrates with or without cavitation, mass Lobar infiltrates with or without cavitation, mass

mimicking bronchogenic carcinoma, or fibronodular mimicking bronchogenic carcinoma, or fibronodular infiltratesinfiltrates

– Skin diseaseSkin disease• Either a verrucous or ulcerative lesion with an Either a verrucous or ulcerative lesion with an

indolent courseindolent course

– Subcutaneous nodulesSubcutaneous nodules• Abscesses commonly associated with systemic Abscesses commonly associated with systemic

manifestationsmanifestations

BlastomycosisBlastomycosis

• Forms of blastomycosis (cont.)Forms of blastomycosis (cont.)– Bone and joint infectionBone and joint infection

• Long bones, ribs, and vertebraeLong bones, ribs, and vertebrae– Osteolytic, well-delineated lesionsOsteolytic, well-delineated lesions

– Genitourinary tract infectionGenitourinary tract infection• Prostate and epididymis (10 to 30% of cases)Prostate and epididymis (10 to 30% of cases)

– OthersOthers• Central nervous systemCentral nervous system

• ThyroidThyroid

• PericardiumPericardium

• Adrenal glandsAdrenal glands

• Gastrointestinal tractGastrointestinal tract

BlastomycosisBlastomycosis• Histopathology of blastomycosisHistopathology of blastomycosis

– Combination of acute suppurative and Combination of acute suppurative and granulomatous inflammationgranulomatous inflammation

– Fungi are usually seen at the edge of the Fungi are usually seen at the edge of the abscessabscess

– The yeast cells are globose to ovoid in shape The yeast cells are globose to ovoid in shape and approximately 8-15 and approximately 8-15 µµm in diameterm in diameter• The single blastoconidium is attached by a broad The single blastoconidium is attached by a broad

base to the parent cellbase to the parent cell• In most cases, predominantly single cells without In most cases, predominantly single cells without

attached blastoconidia are seenattached blastoconidia are seen• The cell wall of the yeast is thick and appears doubly The cell wall of the yeast is thick and appears doubly

refractilerefractile– The mold is composed of septate hyaline The mold is composed of septate hyaline

hyphae and unbranced short conidiophoreshyphae and unbranced short conidiophores• The coniodiophores arise at right angles to the The coniodiophores arise at right angles to the

vegetative hyphaevegetative hyphae

Opportunistic Opportunistic MycosesMycoses

• Most likely opportunistic system Most likely opportunistic system mycosis infections in Southeastern mycosis infections in Southeastern coastal states after hurricane coastal states after hurricane – AspergillosisAspergillosis– ZygomycosisZygomycosis– HyalohyphomycosisHyalohyphomycosis– PhaeohyphomycosisPhaeohyphomycosis

AspergillosisAspergillosis

– AspergillosisAspergillosis•Diseases caused by molds of the genus Diseases caused by molds of the genus

AspergillusAspergillus, most commonly , most commonly A. fumigatus , A. fumigatus , A. flavusA. flavus, and , and A. nigerA. niger

•These organisms are widespread in the These organisms are widespread in the environment including the homeenvironment including the home

•Many species of Many species of AspergillusAspergillus are xerophilic, are xerophilic, thermotolerant, and tolerant to freezingthermotolerant, and tolerant to freezing

AspergillosisAspergillosis

– Aspergillosis (cont.)Aspergillosis (cont.)• Infection is usually acquired via inhalation of Infection is usually acquired via inhalation of

airborne conidiaairborne conidia

•The clinical manifestation and severity of the The clinical manifestation and severity of the disease depends upon the immunologic disease depends upon the immunologic state of the patientstate of the patient

– Lowered host resistance due to such factors as Lowered host resistance due to such factors as underlying debilitating disease, neutropenia, underlying debilitating disease, neutropenia, chemotherapy, disruption of normal flora, and an chemotherapy, disruption of normal flora, and an inflammatory response due to the use of inflammatory response due to the use of antimicrobial agents and steroids can predispose antimicrobial agents and steroids can predispose the patient to colonization, invasive disease, or the patient to colonization, invasive disease, or bothboth

AspergillosisAspergillosis• Forms of aspergillosisForms of aspergillosis

– Allergic bronchopulmonary Allergic bronchopulmonary • Sinuses, lungsSinuses, lungs

– Pulmonary aspergillomaPulmonary aspergilloma• Pre-existing lung cavityPre-existing lung cavity

– Invasive aspergillosisInvasive aspergillosis• CNSCNS• PulmonaryPulmonary• SinonasalSinonasal• OsteomyelitisOsteomyelitis• EndophthalmitisEndophthalmitis• EndocarditisEndocarditis• Renal abscessesRenal abscesses• CutaneousCutaneous

AspergillosisAspergillosis

• Histopathology of aspergillosisHistopathology of aspergillosis– The tissue reaction is acute suppurative The tissue reaction is acute suppurative

inflammation with areas of ischemic inflammation with areas of ischemic necrosisnecrosis•Blood vessel invasion, thrombosis, Blood vessel invasion, thrombosis,

infarction, and dissemination are extremely infarction, and dissemination are extremely commoncommon

– The fungus proliferates as septate The fungus proliferates as septate hyphae 2.5-4.5 hyphae 2.5-4.5 µµm in diameterm in diameter•The hyphae branch dichotomously (approx. The hyphae branch dichotomously (approx.

45 degree angle)45 degree angle)

ZygomycosisZygomycosis

• ZygomycosisZygomycosis– The angiotropic (blood vessel-invading) The angiotropic (blood vessel-invading)

infection produced by the various infection produced by the various ZygomycetesZygomycetes•The leading pathogens in this group are The leading pathogens in this group are

species of the genera species of the genera MucorMucor, , RhizopusRhizopus, , RhizomucorRhizomucor, and , and AbsidiaAbsidia

– These fungi are ubiquitous in the These fungi are ubiquitous in the environment, being found in soil and on environment, being found in soil and on decaying matter, as well as on fruit and decaying matter, as well as on fruit and breadbread

ZygomycosisZygomycosis

• Zygomycosis (cont.)Zygomycosis (cont.)– Conditions and factors that place Conditions and factors that place

patients at risk for zygomycosis include patients at risk for zygomycosis include poorly controlled diabetes mellitus, poorly controlled diabetes mellitus, leukemia, lymphoma, corticosteroid leukemia, lymphoma, corticosteroid therapy, malnutrition, organ therapy, malnutrition, organ transplantation, and extensive burnstransplantation, and extensive burns

– Mycoses are generally acute and rapidly Mycoses are generally acute and rapidly developing in debilitated patientsdeveloping in debilitated patients

ZygomycosisZygomycosis

– Zygomycotic infectionZygomycotic infection•The infection typically involves the The infection typically involves the

rhino-facial-cranial area, lungs, rhino-facial-cranial area, lungs, gastrointestinal tract, and skingastrointestinal tract, and skin

•The fungi show a predilection for The fungi show a predilection for vessel (arterial) invasion resulting in vessel (arterial) invasion resulting in embolization and necrosis of embolization and necrosis of surrounding tissuesurrounding tissue

•Rhinocerebral disease in acidotic Rhinocerebral disease in acidotic patients usually results in death, often patients usually results in death, often within a few dayswithin a few days

ZygomycosisZygomycosis

• Histopathology of zygomycosisHistopathology of zygomycosis– The tissue reaction is usually slightThe tissue reaction is usually slight

•Acute suppurative inflammation Acute suppurative inflammation predominates with focal areas of predominates with focal areas of granulomatous inflammationgranulomatous inflammation

– Hyphae usually vary from 6-50 Hyphae usually vary from 6-50 µµm in m in diameter, are sparsely septate, and diameter, are sparsely septate, and irregularly branchedirregularly branched

– The organism characteristically invades The organism characteristically invades the walls of adjacent blood vessels, the walls of adjacent blood vessels, producing thrombosis and infarction, but producing thrombosis and infarction, but rarely disseminates through the vesselsrarely disseminates through the vessels

ZygomycosisZygomycosis

• Isolation of ZygomycetesIsolation of Zygomycetes– Inoculate the material onto Sabouraud Inoculate the material onto Sabouraud

dextrose agar and incubate at 30dextrose agar and incubate at 30ºC.ºC.– Sterile bread in a test tube may recover Sterile bread in a test tube may recover

Zygomycetes when other media failZygomycetes when other media fail

HyalohyphomycosisHyalohyphomycosis

• HyalohyphomycosisHyalohyphomycosis– Encompasses infections caused by Encompasses infections caused by

relatively unusual hyaline molds and relatively unusual hyaline molds and yeastsyeasts• Includes over 40 different species classified Includes over 40 different species classified

in 23 generain 23 genera– FusariumFusarium species species– Pseudallescheria boydiiPseudallescheria boydii

FusariumFusarium

• Fusarium Fusarium speciesspecies– A filamentous fungi commonly found in A filamentous fungi commonly found in

soil, on plants, and in organic debris soil, on plants, and in organic debris •Cause of localized infections of the skin, Cause of localized infections of the skin,

nails, and cornea, usually the result of nails, and cornea, usually the result of traumatrauma

• In immunocompromised patients can cause In immunocompromised patients can cause sino-orbital, pulmonary, or disseminated sino-orbital, pulmonary, or disseminated infectionsinfections

– Infections usually follow inhalation, but some Infections usually follow inhalation, but some have originated from cutaneous lesions have originated from cutaneous lesions associated with infected nailsassociated with infected nails

• Pseudallescheria boydiiPseudallescheria boydii– A filamentous fungus found worldwideA filamentous fungus found worldwide

•Has been isolated from soil, sewage, Has been isolated from soil, sewage, contaminated water, and the manure of contaminated water, and the manure of farm animalsfarm animals

– An emerging opportunistic infectionAn emerging opportunistic infection•Usually acquired via contact with soil and Usually acquired via contact with soil and

following minor traumafollowing minor trauma

•Causes cutaneous, sinus, eye, CNS, lung, Causes cutaneous, sinus, eye, CNS, lung, bone, joing, and disseminated infectionsbone, joing, and disseminated infections

Pseudallescheria boydiiPseudallescheria boydii

PhaeohyphomycosisPhaeohyphomycosis

• PhaeohyphomycosisPhaeohyphomycosis– A group of mycotic infections characterized A group of mycotic infections characterized

by the presence of dematiaceous (dark-by the presence of dematiaceous (dark-walled) septate hyphae and sometimes walled) septate hyphae and sometimes yeast or a combination of both in tissueyeast or a combination of both in tissue•These fungi, commonly called “black molds,” These fungi, commonly called “black molds,”

contain the dark brown pigment melanin in their contain the dark brown pigment melanin in their cell wallscell walls

•Many of these fungi are found in soil or on Many of these fungi are found in soil or on decaying plant debrisdecaying plant debris

•The most commonly encountered genera are The most commonly encountered genera are AlternariaAlternaria, , BipolariBipolari, , CurvulariaCurvularia, and , and ExserobilumExserobilum

PhaeohyphomycosisPhaeohyphomycosis

• Forms of phaeohyphomycosisForms of phaeohyphomycosis– SuperficialSuperficial– CutaneousCutaneous– CornealCorneal– SubcutaneousSubcutaneous– Respiratory tract (sinus/lung)Respiratory tract (sinus/lung)– CNSCNS– BoneBone

PhaeohyphomycosisPhaeohyphomycosis

• Morphology of phaeohyphomycosisMorphology of phaeohyphomycosis– The hyphae may be short to elongate, The hyphae may be short to elongate,

distorted or swollen (toruloid hyphae), distorted or swollen (toruloid hyphae), regularly shaped, or any combination of regularly shaped, or any combination of the abovethe above

– The yeast will be variable in size and will The yeast will be variable in size and will show buddingshow budding

• HistopathologyHistopathology– Varied, ranging from tissue reactions Varied, ranging from tissue reactions

associated with walled abscesses to associated with walled abscesses to active tissue invasion by hyphaeactive tissue invasion by hyphae

Human RemainsHuman Remains

• The notion that dead bodies pose an The notion that dead bodies pose an urgent health threat in the aftermath of a urgent health threat in the aftermath of a disaster is one of several myths about disaster is one of several myths about disasters and relief efforts that the Pan disasters and relief efforts that the Pan American Health Organization and the American Health Organization and the World Health Organization have been World Health Organization have been trying to counter for nearly two decadestrying to counter for nearly two decades– The most enduring myth is the idea that dead The most enduring myth is the idea that dead

bodies cause epidemicsbodies cause epidemics• Survivors are much more likely to be a source of Survivors are much more likely to be a source of

disease outbreaksdisease outbreaks• Most victims of natural disasters die of trauma, Most victims of natural disasters die of trauma,

drowning, or burns rather than infection drowning, or burns rather than infection

Human RemainsHuman Remains

• The microorganisms that are involved in The microorganisms that are involved in decomposition are not the kind that cause decomposition are not the kind that cause diseasedisease– Most viruses and bacteria that do cause Most viruses and bacteria that do cause

disease cannot survive more than a few hours disease cannot survive more than a few hours in a dead bodyin a dead body• Exception = HIV, has been shown to live up to 16 Exception = HIV, has been shown to live up to 16

days in a corpse under refrigerationdays in a corpse under refrigeration

– Blood-borne viruses, such as HIV and hepatitis Blood-borne viruses, such as HIV and hepatitis B and C, as well as tuberculosis and B and C, as well as tuberculosis and gastrointestinal infection, do pose a slight risk gastrointestinal infection, do pose a slight risk for relief workers charged with handling bodiesfor relief workers charged with handling bodies

Other Issues That I Do Not Other Issues That I Do Not Have Time To DiscussHave Time To Discuss

• Tetanus Tetanus – Td or Tdap given to all evacuees and Td or Tdap given to all evacuees and

emergency responders with wounds and emergency responders with wounds and unknown vaccination history or > 5 years unknown vaccination history or > 5 years since last dose since last dose

– Tetanus immune globulin (TIG) also given to Tetanus immune globulin (TIG) also given to evacuees with unknown vaccination history evacuees with unknown vaccination history (or < 3 lifetime doses)(or < 3 lifetime doses)

• Rabies – no documented cases post-Rabies – no documented cases post-hurricanehurricane

• Non-tuberculous mycobacterial Non-tuberculous mycobacterial infectionsinfections

ReferencesReferences• Barclay, L. “Epidemiologic Consequences of Hurricane Katrina: A Barclay, L. “Epidemiologic Consequences of Hurricane Katrina: A

Newsmaker Interview with Raoult Ratard, MD”, Newsmaker Interview with Raoult Ratard, MD”, www.medscape.com/viewarticle/513376www.medscape.com/viewarticle/513376

• ““BlastomycesBlastomyces sp.” sp.” www.doctorfungus.org/thefungi/Blastomyceswww.doctorfungus.org/thefungi/Blastomyces• ““Blastomycosis”, Blastomycosis”, www.doctorfungus.org/mycoses/human/blastowww.doctorfungus.org/mycoses/human/blasto• Centers for Disease Control and Prevention, “Interim Health Centers for Disease Control and Prevention, “Interim Health

Recommendations for Workers who Handle Human Remains”, Recommendations for Workers who Handle Human Remains”, www.bt.cdc.gov/disasterswww.bt.cdc.gov/disasters

• Centers for Disease Control Media Relations, “Update on Health Centers for Disease Control Media Relations, “Update on Health Issues Related to Mold, Mildew, and Mud in Hurricane and Flood Issues Related to Mold, Mildew, and Mud in Hurricane and Flood Affected Areas”, Affected Areas”, www.cdc.gov/od/oc/media/transcripts/t050928www.cdc.gov/od/oc/media/transcripts/t050928, , September 28, 2005September 28, 2005

• Eberwine, D. “Disaster Myths That Just Won’t Die”, Eberwine, D. “Disaster Myths That Just Won’t Die”, Perspectives in Perspectives in HealthHealth, 2005, 10(1): 2-7., 2005, 10(1): 2-7.

• Merck, Merck, Introduction to Medical Mycology: Monographs in MedicineIntroduction to Medical Mycology: Monographs in Medicine. . Merck & Co, 2001.Merck & Co, 2001.

• MMWR Dispatch, “Infectious Disease and Dermatologic Conditions MMWR Dispatch, “Infectious Disease and Dermatologic Conditions in Evacuees and Rescue Work After Hurricane Katrina—Multiple in Evacuees and Rescue Work After Hurricane Katrina—Multiple Stats August-September, 2005”, September 26, 2005/54 Stats August-September, 2005”, September 26, 2005/54 (Dispatch); 1-4(Dispatch); 1-4

ReferencesReferences• MMWR Dispatch, MMWR Dispatch, “Vibrio“Vibrio Illness After Hurricane Katrina – Multiple Illness After Hurricane Katrina – Multiple

States, August-September 2005States, August-September 2005”,”, September 14, 2005/54 September 14, 2005/54 (Dispatch); 1-4(Dispatch); 1-4

• World Health Organization, “Flooding and communicable diseases World Health Organization, “Flooding and communicable diseases fact sheet: Risk assessment and preventive measures”, fact sheet: Risk assessment and preventive measures”, www.who.int/hac/techguidance/ems/floodwww.who.int/hac/techguidance/ems/flood

• www.bt.cdc.gov/disasters/foodwater.aspwww.bt.cdc.gov/disasters/foodwater.asp• www.bt.cdc.gov/disasters/hurricanes/katrina/pdf/katrina-leptoclin.www.bt.cdc.gov/disasters/hurricanes/katrina/pdf/katrina-leptoclin.

pdfpdf• www.bt.cdc.gov/disasters/vibriovulnificus.aspwww.bt.cdc.gov/disasters/vibriovulnificus.asp• www.cdc.gov/foodborneoutbreaks/vibrio_sumwww.cdc.gov/foodborneoutbreaks/vibrio_sum• www.dpd.cdc.gov/dpdx/HTML/A-F/Cryptosporidiosis/body_Cryptospwww.dpd.cdc.gov/dpdx/HTML/A-F/Cryptosporidiosis/body_Cryptosp

oridiosisoridiosis• www.dpd.cdc.gov/dpdx/HTML/Frames/G-L/Giardiasis/body_Giardiaswww.dpd.cdc.gov/dpdx/HTML/Frames/G-L/Giardiasis/body_Giardias

isis• www.reutershealth.comwww.reutershealth.com, “Hurricanes bring no increase in West , “Hurricanes bring no increase in West

Nile cases”, October 12, 2005Nile cases”, October 12, 2005• ““Zygomycosis”, Zygomycosis”,

www.doctorfungus.org/mycoses/human/zygo/zygomycosiswww.doctorfungus.org/mycoses/human/zygo/zygomycosis