268114 Typhoid Fever

Qurrataini I. Balocang MED IA 1

Individual ReportIndividual Report

TYPHOID TYPHOID FEVERFEVER


Typhoid Fever

Enteric FeverParatyphoid Fever

Rose SpotSalmonella typhi

Salmonella partyphi


What is typhoid fever?

• Typhoid fever is a bacterial infection of the intestinal tract and occasionally the bloodstream.

• The disease rarely occurs in developed countries. It is most commonly seen in countries with poor sanitary conditions and contaminated water supplies.

• Most of the cases are acquired during foreign travel to underdeveloped countries.


What is typhoid fever?

• Outbreaks are rare.

• The germ that causes typhoid is a unique human strain of Salmonella called Salmonella typhi.


Causes

• It is caused by infection with Salmonella typhi –

a bacteria found in infected animals and transmitted to persons in contaminated food or fluids. It is most often found in countries with poor sanitary conditions or contaminated water supplies. Boiling water and thoroughly cooking food can kill the microorganism. The infection can also be spread asymptomatic carriers. These are people who have the bacteria in their gastrointestinal tract, but do not have symptoms.


Who gets typhoid fever?

Anyone can get typhoid fever but the greatest risk exists to travelers visiting countries where the disease is common.

Occasionally, local cases can be traced to exposure to a person who is a chronic carrier.

• Infants and persons over 60 usually have the severest cases.


Pathophysiology

Systemic bacterial infection (Enteric Fever)

1.Salmonella typhi (Typhoid fever) – Most common and more severe form

2. Salmonella paratyphi (Paratyphoid fever) – Much more mild than Typhoid fever


Transmission

Ingestion of contaminated food

• Typhoid germs are passed in the feces and, to some extent, the urine of infected people.

• The germs are spread by eating or drinking water or foods contaminated by feces from the infected individual.


• World: 17 million cases per year • U.S.: 400 cases per year (70% in travelers)• PHILIPPINES (Nov 2006) 478 in Agusan del Sur. (May 2004) 292 in Bacolod City

Epidemiology: Incidence


Risk factors

• Travel to developing country or refugee camp

• Highly dense living conditions


What are the symptoms?

• The symptoms may occur rapidly, particularly in children.

• However, in adults, they usually come on slowly

Relapses are common.

Fatalities are less than 1% with antibiotic treatment.

Symptoms generally appear one to three weeks after exposure.


Symptoms:

• Incubation (first 7-14 days after ingestion) Usually asymptomatic • Diarrhea may occur • Active infection • Severe Headache • Generalized Abdominal Pain • Anorexia • Constipation more common than Diarrhea • Fever [usually higher in the evening]

– Intermittent Fever initially – Sustained Fever to high temperatures later


Signs:

• Pulse-Temperature Dissociation (uncommon) • Rose Spots (Pathognomonic, present in 25% of cases)

Blanching pink macular spots 2-3 mm over trunk

Complications: (occurs in 10-15% of cases)

• Gastrointestinal Bleeding (2-10% of cases) • Bowel perforation • Typhoid encephalopathy


For how long can an infected person carry the typhoid germ?

• The carrier stage varies from a number of days to years.

• Only about 3% of cases go on to become lifelong carriers of the germ and

• This tends to occur more often in adults than in children.


Laboratory Exam

• Blood Culture • Best Test Sensitivity in first week • Bone Marrow culture • Higher sensitivity than Blood Culture • Fecal culture • Low sensitivity (~33%) • Salmonella serology (Widal's Test) • Poor Test Specificity • Low Test Sensitivity (70%)


Should infected people be isolated?

Because the germ is passed in the feces of infected people, only people with active diarrhea who are unable to control their bowel habits (infants, certain handicapped individuals) should be isolated.

Most infected people may return to work or school when they have recovered, provided that they carefully wash hands after toilet visits.

Children in daycare, health care workers, and persons in other sensitive settings must obtain the approval of the local or state health department before returning to their routine activities.

Food handlers may not return to work until three consecutive negative stool cultures are confirmed.


Is there a vaccine for typhoid?

A vaccine is available

but is generally reserved for people traveling to underdeveloped countries where significant exposure may occur. Strict attention to food and water precautions while traveling to such countries is the most effective preventive method.


Management: Antibiotics

Specific antibiotics are often used to treat cases of typhoid.

• Antibiotic Resistance is increasing

• First-Line: Fluoroquinolones

• Alternative antibiotics (resistance is common)

– Chloramphenicol

– Amoxicillin

– Trimethoprim-Sulfamethoxazole (Septra)


Prevention

• Choose foods processed for safety • Prepare food carefully • Foods prepared by others (avoid if possible) • Keep food contact surfaces clean (3 wash cycle) • Eat cooked food as soon as possible • Maintain clean hands • Steam or boil shellfish at least 10 minutes • All milk and dairy products should be pasteurized • Control fly populations


Mary Mallon (September 23, 1869 – November 11, 1938)



Also known as Typhoid Mary

was the first person in the United States to be identified as a healthy carrier of typhoid fever.

She seemed a healthy woman when a health inspector knocked on her door in 1907, yet she was the cause of several typhoid outbreaks.



Since Mary was the first "healthy carrier" of typhoid fever in the United States, she did not understand how someone not sick could spread disease -- so she tried to fight back.

She was forcibly quarantined twice by public health authorities and died in quarantine.

Over the course of her career as a cook, she infected 47 people, three of whom died from the disease.

It was also possible that she was born with the disease, as her mother had typhoid fever during her pregnancy.



MaryMallon died on November 11, 1938 at the age of 69

due to pneumonia (not typhoid), six years after a stroke had left her paralyzed.

However, an autopsy found evidence of live typhoid bacteria in her gallbladder.

Her body was cremated with burial in Saint Raymond's Cemetery in the Bronx.


Causative Agent: Salmonella typhiA serovar of Salmonella enterica (formerly known as Salmonella choleraesuis)

Salmonella Typhi possesses 3 main antigenic factors: 1. the O, or somatic antigen; 2. the Vi, or encapsulation antigen; and

3. the H, or flagellar antigen

Virulence Factors: S. typhi has a combination of characteristics that make it an effective pathogen. This species contains an endotoxin typical of Gram negative organisms, as well as the Vi antigen which is thought to increase virulence. It also produces and excretes a protein known as “invasin” that allows non-phagocytic cells to take up the bacterium, where it is able to live intracellularly. It is also able to inhibit the oxidative burst of leukocytes, making innate immune response ineffective.


INTRODUCTION:Worldwide, typhoid fever affects roughly 17 million people annually, causing nearly 600,000 deaths. The causative agent, Salmonella enterica typhi (referred to as Salmonella typhi from now on), is an obligate parasite that has no known natural reservoir outside of humans. Little is known about the historical emergence of human S. typhi infections, however it is thought to have caused the deaths of many famous figures such as British author and poet Rudyard Kipling, the inventor of the airplane, Wilbur Wright, and the Greek Empire’s Alexander the Great. The earliest recorded epidemic occurred in Jamestown, VA where it is thought that 6,000 people died of typhoid fever in the early 17th Century. This disease is rare in the United States and developed nations, but always poses the risk of emergence.

Causative Agent: Salmonella typhi


HISTORY:Originally isolated in 1880 by Karl J. Erberth, S. typhi is a multi-organ pathogen that inhabits the lympathic tissues of the small intestine, liver, spleen, and bloodstream of infected humans. It is not known to infect animals and is most common in developing countries with poor sanitary systems and lack of antibiotics, putting travelers to Asia, Latin America, and Africa in a high risk group. Of the 266 people infected in the United States in 2002, approximately 70% had traveled internationally within 6 weeks of the onset of disease.



Causative Agent: Salmonella typhiDESCRIPTION: Salmonella typhi (more commonly known as the bacteria responsible for typhoid fever) can be very dangerous if not taken care of properly.

-only live in the bloodstream or intestinal tract of humans,-but is also found in sewage.

Even though most people either die or use antibiotics to stop the growth of these bacteria, a very small percentage of the people who get typhoid fever have certain antibodies that are able to restrict the growth of salmonella typhi and therefore are able to live.

These people plus the people that are cured through antibiotics are called carriers because even though they will have no more symptoms of typhoid fever, they will still have the bacteria inside of them.

Since salmonella typhi is passed through bodily fluids, you can contract it by eating some food or a drink handled by a carrier. You can also contract these bacteria by having food or water that has been contaminated with sewage containing salmonella typhi.


MICROBIOLOGICAL CHARACTERISTICS:This gram-negative enteric bacillus belongs to the family Enterobacteriaceae.

It is a motile, facultative anaerobe that is susceptible to various antibiotics.

Currently, 107 strains of this organism have been isolated, many containing varying metabolic characteristics, levels of virulence, and multi-drug resistance genes that complicate treatment in areas that resistance is prevalent.

Diagnostic identification can be attained by growth on MacConkey and EMB agars, and the bacteria is strictly non-lactose fermenting. It also produces no gas when grown in TSI media, which is used to differentiate it from other Enterobacteriaceae.



MOST COMMON VICTIMS:Humans in countries where the water is contaminated with sewage, which can

sometimes contain salmonella typhi.

WHERE IT IS FOUND: Usually found contracted in the developing nations of the world such as the Latin

American, African, and Asian countries. The reason for this is that the water in these countries is contaminated often with sewage that on some occasions is carrying Salmonella typhi.

SYMPTOMS: Typhoid fever can cause a variety of symptoms to occur to the person that has

contracted Salmonella typhi. Some of the most common symptoms are severe headaches, abdominal pains, fevers, and diarrhea. Sometimes, rose-colored spots can appear on the abdomen and chest. One severe long-term effect that can occur is that the bacteria can produce ulcers on the intestinal walls. This can later lead to holes forming in the intestine walls and the allowing of the contents of the intestine to spill into the abdomen, causing severe abdominal pain and infection.



RATE OF DAMAGE: The symptoms of typhoid fever can begin to occur one to three weeks after the

person has contracted Salmonella typhi. These symptoms then usually get the worst during the third week of symptoms and then subside. By the fourth week, many people do not have any of the symptoms of typhoid fever.

NUMBER OF VICTIMS:Typhoid fever affects about 400 people in the United States each year. Of these

400 people, 70% of them got the Salmonella typhi while traveling internationally. In developing nations though, 12.5 million people are affected by this disease each year.

WEAPONS AGAINST IT: Today, there are many antibiotics that are available to restrict the growth of

Salmonella typhi. Some of these are ampicillin, trimethoprim-sulfamethoxazole, and ciprofloxacin. The most effective weapon against Salmonella typhi though is good personal hygiene and public sanitation.


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268114 Typhoid Fever