Rot a Viruses

8/14/2019 Rot a Viruses

1/29

ROTAVIRALROTAVIRAL

diarrheasdiarrheas

Dr.T.V.Rao MDDr.T.V.Rao MD


2/29

Importance of RotavirusesImportance of Rotaviruses

Rotaviruses are major cause of diarrhealRotaviruses are major cause of diarrheal

illness in Human infants in the worldillness in Human infants in the world Adults too can get infectedAdults too can get infected

Young animals, calves, piglets can alsoYoung animals, calves, piglets can also

infectedinfected


3/29

Rota virus SeasonalRota virus Seasonal

ImpactImpact Rotavirus infections spread easily.Rotavirus infections spread easily.

Outbreaks usually occur in the winter andOutbreaks usually occur in the winter and

early spring, between about Novemberearly spring, between about Novemberand April. Rotavirus infections oftenand April. Rotavirus infections often

spread in settings where many childrenspread in settings where many children

are together, such as daycare centres.are together, such as daycare centres.


4/29

Global Impact of RotavirusGlobal Impact of Rotavirus

InfectionsInfections


5/29

Characters of RotavirusCharacters of Rotavirus

A rotavirus has a characteristic wheel-likeA rotavirus has a characteristic wheel-like

appearance when viewed by electronappearance when viewed by electron

microscopy (the name rotavirus is derived frommicroscopy (the name rotavirus is derived fromthe Latin rota, meaning "wheel"). Rotavirusesthe Latin rota, meaning "wheel"). Rotaviruses

are non enveloped, double-shelled viruses.are non enveloped, double-shelled viruses.

The genome is composed of 11 segments ofThe genome is composed of 11 segments of

double-stranded RNA, which code for sixdouble-stranded RNA, which code for sixstructural and five nonstructural proteins. Thestructural and five nonstructural proteins. The

virus is stable in the environmentvirus is stable in the environment


6/29

Rotavirus resembles a wheelRotavirus resembles a wheel

( Rota = Wheel )( Rota = Wheel )


7/29

Classification ofClassification of

RotavirusesRotaviruses

Rota viruses are classified as FiveRota viruses are classified as Five

species ( A- E )species ( A- E ) Two other species are tentativelyTwo other species are tentatively

identifiedidentified

( F and G )( F and G )


8/29

Structure of RotavirusesStructure of Rotaviruses

Antigenic classificationAntigenic classification

mainly dependent onmainly dependent on

structural protein VP6structural protein VP6

Group A is importantGroup A is important

human pathogenhuman pathogen

Outer capsid protein VP4Outer capsid protein VP4

and VP7 carry epitopesand VP7 carry epitopes

important in neutralizingimportant in neutralizingantibodiesantibodies


9/29

Structural configuration ofStructural configuration of

RotavirusRotavirus


10/29

PathogenictyPathogenicty

The virus infect the villi of the small intestineThe virus infect the villi of the small intestine (Gastric(Gastricand colonic mucosa are not infected)and colonic mucosa are not infected)

They multiply in the cytoplasam of the enterocytes andThey multiply in the cytoplasam of the enterocytes and

damage their transport mechanisms.damage their transport mechanisms. The Rota viral encoded particle NSP4 is a viralThe Rota viral encoded particle NSP4 is a viral

enterotoxin and induces secretions by triggering aenterotoxin and induces secretions by triggering asignal transduction pathwaysignal transduction pathway

Damaged cell may show into lumen of the intestinalDamaged cell may show into lumen of the intestinaland release large quantities of virus which appear inand release large quantities of virus which appear inthe stool.the stool.

Viral excretion usually lasts for 2 12 days inViral excretion usually lasts for 2 12 days inotherwise healthy patientsotherwise healthy patients


11/29

Why Diarrhea in Rota viralWhy Diarrhea in Rota viral

InfectionsInfections

Diarrhea caused byDiarrhea caused by

Rotaviruses may beRotaviruses may bedue to impaireddue to impaired

sodium and glucosesodium and glucose

absorption asabsorption as

damaged cell on villidamaged cell on villiare replaced by nonare replaced by non

absorbing immatureabsorbing immature

crypt cellcrypt cell


12/29

Immunity in Rota viralImmunity in Rota viral

InfectionsInfections By age 3 years, 90% ofBy age 3 years, 90% of

the children have serumthe children have serumantibodies to one orantibodies to one or

more typesmore types Young children sufferYoung children suffer

upto to five reinfectionsupto to five reinfectionsby 2 years of ageby 2 years of age

Secretary IgA orSecretary IgA or

Interferon are importantInterferon are importantin protection againstin protection againstRota viral infectionsRota viral infections..


13/29

Impact of Rota viralImpact of Rota viral

InfectionsInfections Rotavirus is the most common cause of severeRotavirus is the most common cause of severe

diarrhea among children, resulting in the hospitalizationdiarrhea among children, resulting in the hospitalizationof approximately 55,000 children each year in theof approximately 55,000 children each year in the

United States and the death of over 600,000 childrenUnited States and the death of over 600,000 childrenannually worldwide. The incubation period for rotavirusannually worldwide. The incubation period for rotavirusdisease is approximately 2 days. The disease isdisease is approximately 2 days. The disease ischaracterized by vomiting and watery diarrhea for 3 - 8characterized by vomiting and watery diarrhea for 3 - 8days, and fever and abdominal pain occur frequently.days, and fever and abdominal pain occur frequently.

Immunity after infection is incomplete, but repeatImmunity after infection is incomplete, but repeatinfections tend to be less severe than the originalinfections tend to be less severe than the originalinfection.infection.


14/29

Rota viral infectionRota viral infection

damages Intestinesdamages Intestines Pathogens, e.g., rotavirus, may strip the tips ofPathogens, e.g., rotavirus, may strip the tips of

the villi from large patches of the intestinal wallthe villi from large patches of the intestinal wallthus decreasing the surface area andthus decreasing the surface area and

decreasing by more than 50% the specificdecreasing by more than 50% the specificabsorptive capacities of the intestine. Theabsorptive capacities of the intestine. Theresult is malabsorption which can causeresult is malabsorption which can causemalnutrition - most especially in a child alreadymalnutrition - most especially in a child already

nutritionally compromised by repeated previousnutritionally compromised by repeated previousattacks of diarrhea.attacks of diarrhea.


15/29

Clinical FindingsClinical Findings

Rotavirus cause major events of diarrheal diseases inRotavirus cause major events of diarrheal diseases inchildren and infants worldwidechildren and infants worldwide

Incubation period is 1 3 days.Incubation period is 1 3 days. Present withPresent with

Watery diarrheaWatery diarrhea

FeverFever

Abdominal painAbdominal pain

Vomitting leading to dehydrationVomitting leading to dehydrationLoss of electrolytes and fluidsLoss of electrolytes and fluids

May be fatal unless treatedMay be fatal unless treated

Patients with milder disease recovers promptly in 3 Patients with milder disease recovers promptly in 3 8 days8 days


16/29

Dehydration is leading causeDehydration is leading cause

in Morbidity and Mortalityin Morbidity and Mortality


17/29

Rotavirus have great impactRotavirus have great impact

on Infants and Childrenon Infants and Children


18/29

Rota viral infection inRota viral infection in

Immunosuppresed andImmunosuppresed and

othersothers

In children with immunodeficienes , RotavirusIn children with immunodeficienes , Rotaviruscause sever and prolonged disease.cause sever and prolonged disease.

Adults seroconvert but not manfiest withAdults seroconvert but not manfiest withdiarrheadiarrhea

However in closed wards sever disease canHowever in closed wards sever disease can

occur.occur. In India and China large outbreaks of severeIn India and China large outbreaks of severe

gastroenteritis have occuredgastroenteritis have occured


19/29

Laboratory DiagnosisLaboratory Diagnosis

Microscopy ( EM )Microscopy ( EM )

Demonstration ofDemonstration ofVirus in stool helps inVirus in stool helps in

early diseaseearly disease

Electron MicroscopyElectron Microscopy

has made thehas made the

identification simpleridentification simpler


20/29

Other Methods inOther Methods in

DiagnosisDiagnosis

Virus can beVirus can be

demonstrated by IEMdemonstrated by IEM

Latex agglutinationLatex agglutinationteststests

ELISA can detectELISA can detect

antibodies andantibodies and

establishing raiseestablishing raisein titersin titers


21/29

GenotypingGenotyping Genotyping is mostGenotyping is most

sensitive method forsensitive method fordetection ofdetection of

Rotavirus nucleicRotavirus nucleic

acid from stoolacid from stool

specimensspecimens


22/29

TreatmentTreatment

Treatment of Gastroenteritis is supportiveTreatment of Gastroenteritis is supportive

Correction of Loss of water and electrolytesCorrection of Loss of water and electrolytes

Failure for prompt correction of dehydration leads toFailure for prompt correction of dehydration leads to

AcidosisAcidosis

ShockShock

DeathDeath

Correction Electrolyte remain the goal treatment in RotaCorrection Electrolyte remain the goal treatment in Rota

viral infections.viral infections.Lesser deaths if effective replacement therapy is initiatedLesser deaths if effective replacement therapy is initiated


23/29

UNICEF/WHO O.R.SUNICEF/WHO O.R.S

Sodium Chloride 3.5 gramsSodium Chloride 3.5 grams

Sodium Bicarbonate 2.5 gramsSodium Bicarbonate 2.5 grams

Potassium Chloride 1.5 gramsPotassium Chloride 1.5 grams

Glucose 20 gramsGlucose 20 grams

To be dissolved in one liter of cleanTo be dissolved in one liter of clean

drinking waterdrinking water


24/29

Fluid ReplacementFluid Replacement Management consists of replacement ofManagement consists of replacement of

fluids ( ORS ) and restoration offluids ( ORS ) and restoration ofElectrolyte balanceElectrolyte balance

Oral rehydration Therapy is highlyOral rehydration Therapy is highlyeffective in reducing morbidity andeffective in reducing morbidity andmortalitymortality

Severe dehydration needs parentalSevere dehydration needs parentaladministration of fluids.administration of fluids.


25/29

Basic measures in RotaBasic measures in Rota

viral preventionviral prevention

Keep your handsKeep your hands

clean. Wash handsclean. Wash handsoften with soap andoften with soap and

warm water afterwarm water after

using the toilet,using the toilet,

diapering and beforediapering and beforepreparing or eatingpreparing or eating

food.food.


26/29

EpidemiologyEpidemiology

Rotaviral infections continue to be mostRotaviral infections continue to be most

important cause of Gastroenteritis inimportant cause of Gastroenteritis in

young childrenyoung children Estimates range 3 billion 5 billionEstimates range 3 billion 5 billion

infectionsinfections

Children > 5 years age highly susceptibleChildren > 5 years age highly susceptibleto infectionsto infections

Results in 1 million deathsResults in 1 million deaths


27/29

Impact on HospitalsImpact on Hospitals

Upto 50 % of cases of AcuteUpto 50 % of cases of Acute

Gastroenteritis of the HospitalizedGastroenteritis of the Hospitalizedchildren throught the world are caused bychildren throught the world are caused by

RotavirusRotavirus

Winter season highly predisposingWinter season highly predisposing Nosocomial infections need attentionNosocomial infections need attention


28/29

Prevention and ControlPrevention and Control

In view of fecal oral route of transmissionIn view of fecal oral route of transmissionwaste water management, safe waterwaste water management, safe water

supplies sanitation are significant controlsupplies sanitation are significant controlmeasurers.measurers.

Vaccine Vaccine In 2006 an Oral Bovine basedIn 2006 an Oral Bovine basedRota viral vaccine was licensed in USARota viral vaccine was licensed in USA


29/29

Educational materialEducational material

on Rota viral Diarrheaon Rota viral Diarrheafor Graduate Medicalfor Graduate Medical

StudentsStudents Dr.T.V.Rao MDDr.T.V.Rao MDEmailEmail

doctortvrao@gmail comdoctortvrao@gmail com

Documents

Rot a Viruses