rotaviruses
TRANSCRIPT
ROTAVIRUSESROTAVIRUSES
Dr.T.V.Rao MDDr.T.V.Rao MD
Importance of RotavirusesImportance of Rotaviruses
Rotaviruses are major cause of Rotaviruses are major cause of diarrheal illness in Human infants in diarrheal illness in Human infants in the worldthe world
Adults too can get infectedAdults too can get infected Young animals, calves, piglets can Young animals, calves, piglets can
also infectedalso infected
Rota virus –Seasonal ImpactRota virus –Seasonal Impact
Rotavirus infections spread easily. Rotavirus infections spread easily. Outbreaks usually occur in the winter Outbreaks usually occur in the winter and early spring, between about and early spring, between about November and April. Rotavirus November and April. Rotavirus infections often spread in settings infections often spread in settings where many children are together, where many children are together, such as daycare centres. such as daycare centres.
Global Impact of Rotavirus Global Impact of Rotavirus InfectionsInfections
Characters of RotavirusCharacters of Rotavirus
A rotavirus has a characteristic wheel-like A rotavirus has a characteristic wheel-like appearance when viewed by electron appearance when viewed by electron microscopy (the name rotavirus is derived microscopy (the name rotavirus is derived from the Latin rota, meaning "wheel"). from the Latin rota, meaning "wheel"). Rotaviruses are non enveloped, double-Rotaviruses are non enveloped, double-shelled viruses. The genome is composed shelled viruses. The genome is composed of 11 segments of double-stranded RNA, of 11 segments of double-stranded RNA, which code for six structural and five which code for six structural and five nonstructural proteins. The virus is stable nonstructural proteins. The virus is stable in the environment in the environment
Rotavirus resembles a wheelRotavirus resembles a wheel( Rota = Wheel )( Rota = Wheel )
Classification of RotavirusesClassification of Rotaviruses
Rota viruses are classified as Five Rota viruses are classified as Five species ( A- E )species ( A- E )
Two other species are tentatively Two other species are tentatively identifiedidentified
( F and G )( F and G )
Structure of RotavirusesStructure of Rotaviruses
Antigenic classification Antigenic classification mainly dependent on mainly dependent on structural protein VP6structural protein VP6
Group A is important Group A is important human pathogenhuman pathogen
Outer capsid protein Outer capsid protein VP4 and VP7 carry VP4 and VP7 carry epitopes important in epitopes important in neutralizing antibodiesneutralizing antibodies
Structural configuration of Structural configuration of RotavirusRotavirus
PathogenictyPathogenicty The virus infect the villi of the small intestineThe virus infect the villi of the small intestine
(Gastric and colonic mucosa are not infected) (Gastric and colonic mucosa are not infected) They multiply in the cytoplasam of the They multiply in the cytoplasam of the
enterocytes and damage their transport enterocytes and damage their transport mechanisms.mechanisms.
The Rota viral encoded particle NSP4 is a viral The Rota viral encoded particle NSP4 is a viral enterotoxin and induces secretions by triggering enterotoxin and induces secretions by triggering a signal transduction pathwaya signal transduction pathway
Damaged cell may show into lumen of the Damaged cell may show into lumen of the intestinal and release large quantities of virus intestinal and release large quantities of virus which appear in the stool.which appear in the stool.
Viral excretion usually lasts for 2 – 12 days in Viral excretion usually lasts for 2 – 12 days in otherwise healthy patientsotherwise healthy patients
Why Diarrhea in Rota viral Why Diarrhea in Rota viral InfectionsInfections
Diarrhea caused by Diarrhea caused by Rotaviruses may Rotaviruses may be due to impaired be due to impaired sodium and sodium and glucose absorption glucose absorption as damaged cell on as damaged cell on villi are replaced by villi are replaced by non absorbing non absorbing immature crypt cellimmature crypt cell
Immunity in Rota viral InfectionsImmunity in Rota viral Infections
By age 3 years, 90% By age 3 years, 90% of the children have of the children have serum antibodies to serum antibodies to one or more typesone or more types
Young children suffer Young children suffer upto to five upto to five reinfections by 2 years reinfections by 2 years of ageof age
Secretary IgA or Secretary IgA or Interferon are Interferon are important in important in protection against protection against Rota viral infectionsRota viral infections..
Impact of Rota viral InfectionsImpact of Rota viral Infections Rotavirus is the most common cause of severe Rotavirus is the most common cause of severe
diarrhea among children, resulting in the diarrhea among children, resulting in the hospitalization of approximately 55,000 children hospitalization of approximately 55,000 children each year in the United States and the death of each year in the United States and the death of over 600,000 children annually worldwide. The over 600,000 children annually worldwide. The incubation period for rotavirus disease is incubation period for rotavirus disease is approximately 2 days. The disease is approximately 2 days. The disease is characterized by vomiting and watery diarrhea characterized by vomiting and watery diarrhea for 3 - 8 days, and fever and abdominal pain for 3 - 8 days, and fever and abdominal pain occur frequently. Immunity after infection is occur frequently. Immunity after infection is incomplete, but repeat infections tend to be less incomplete, but repeat infections tend to be less severe than the original infection. severe than the original infection.
Rota viral infection damages Rota viral infection damages IntestinesIntestines
Pathogens, e.g., rotavirus, may strip the Pathogens, e.g., rotavirus, may strip the tips of the villi from large patches of the tips of the villi from large patches of the intestinal wall thus decreasing the surface intestinal wall thus decreasing the surface area and decreasing by more than 50% area and decreasing by more than 50% the specific absorptive capacities of the the specific absorptive capacities of the intestine. The result is malabsorption intestine. The result is malabsorption which can cause malnutrition - most which can cause malnutrition - most especially in a child already nutritionally especially in a child already nutritionally compromised by repeated previous compromised by repeated previous attacks of diarrhea.attacks of diarrhea.
Clinical FindingsClinical Findings
Rotavirus cause major events of diarrheal Rotavirus cause major events of diarrheal diseases in children and infants worldwidediseases in children and infants worldwide
Incubation period is 1 – 3 days.Incubation period is 1 – 3 days. Present with Present with Watery diarrheaWatery diarrhea FeverFever Abdominal painAbdominal pain Vomitting leading to dehydrationVomitting leading to dehydration Loss of electrolytes and fluidsLoss of electrolytes and fluids May be fatal unless treatedMay be fatal unless treated Patients with milder disease recovers promptly Patients with milder disease recovers promptly
in 3 – 8 daysin 3 – 8 days
Dehydration is leading cause in Dehydration is leading cause in Morbidity and MortalityMorbidity and Mortality
Rotavirus have great impact on Rotavirus have great impact on Infants and ChildrenInfants and Children
Rota viral infection in Rota viral infection in Immunosuppresed and othersImmunosuppresed and others
In children with immunodeficienes , In children with immunodeficienes , Rotavirus cause sever and prolonged Rotavirus cause sever and prolonged disease.disease.
Adults seroconvert but not manfiest with Adults seroconvert but not manfiest with diarrheadiarrhea
However in closed wards sever disease However in closed wards sever disease can occur.can occur.
In India and China large outbreaks of In India and China large outbreaks of severe gastroenteritis have occuredsevere gastroenteritis have occured
Laboratory DiagnosisLaboratory Diagnosis
Microscopy ( EM )Microscopy ( EM )
Demonstration of Demonstration of Virus in stool helps Virus in stool helps in early diseasein early disease
Electron Electron Microscopy has Microscopy has made the made the identification identification simplersimpler
Other Methods in DiagnosisOther Methods in Diagnosis
Virus can be Virus can be demonstrated by demonstrated by IEMIEM
Latex agglutination Latex agglutination teststests
ELISA can detect ELISA can detect antibodies and antibodies and establishing establishing raise in titersraise in titers
GenotypingGenotyping
Genotyping is most Genotyping is most sensitive method sensitive method for detection of for detection of Rotavirus nucleic Rotavirus nucleic acid from stool acid from stool specimensspecimens
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 Failure for prompt correction of dehydration leads
to to AcidosisAcidosis ShockShock DeathDeath Correction Electrolyte remain the goal treatment in Correction Electrolyte remain the goal treatment in
Rota viral infections.Rota viral infections.Lesser deaths if effective replacement therapy is Lesser deaths if effective replacement therapy is
initiatedinitiated
UNICEF/WHO O.R.SUNICEF/WHO O.R.S
Sodium Chloride 3.5 grams Sodium Chloride 3.5 grams Sodium Bicarbonate 2.5 grams Sodium Bicarbonate 2.5 grams Potassium Chloride 1.5 grams Potassium Chloride 1.5 grams Glucose 20 grams Glucose 20 grams To be dissolved in one liter of clean To be dissolved in one liter of clean
drinking water drinking water
Fluid ReplacementFluid Replacement
Management consists of replacement Management consists of replacement of fluids ( ORS ) and restoration of of fluids ( ORS ) and restoration of Electrolyte balanceElectrolyte balance
Oral rehydration Therapy is highly Oral rehydration Therapy is highly effective in reducing morbidity and effective in reducing morbidity and mortalitymortality
Severe dehydration needs parental Severe dehydration needs parental administration of fluids.administration of fluids.
Basic measures in Rota viral Basic measures in Rota viral preventionprevention
Keep your hands Keep your hands clean. Wash hands clean. Wash hands often with soap often with soap and warm water and warm water after using the after using the toilet, diapering toilet, diapering and before and before preparing or eating preparing or eating food. food.
EpidemiologyEpidemiology
Rotaviral infections continue to be Rotaviral infections continue to be most important cause of most important cause of Gastroenteritis in young childrenGastroenteritis in young children
Estimates range 3 billion – 5 billion Estimates range 3 billion – 5 billion infectionsinfections
Children > 5 years age highly Children > 5 years age highly susceptible to infectionssusceptible to infections
Results in 1 million deathsResults in 1 million deaths
Impact on HospitalsImpact on Hospitals
Upto 50 % of cases of Acute Upto 50 % of cases of Acute Gastroenteritis of the Hospitalized Gastroenteritis of the Hospitalized children throught the world are children throught the world are caused by Rotaviruscaused by Rotavirus
Winter season highly predisposingWinter season highly predisposing Nosocomial infections need attentionNosocomial infections need attention
Prevention and ControlPrevention and Control
In view of fecal oral route of In view of fecal oral route of transmission waste water transmission waste water management, safe water supplies management, safe water supplies sanitation are significant control sanitation are significant control measurers.measurers.
Vaccine –Vaccine – In 2006 an Oral Bovine In 2006 an Oral Bovine based Rota viral vaccine was based Rota viral vaccine was licensed in USAlicensed in USA
Educational material on Educational material on Rota viral Diarrhea for Rota viral Diarrhea for
Graduate Medical Graduate Medical StudentsStudents
Dr.T.V.Rao MDDr.T.V.Rao MD
[email protected]@yahoo.co.in