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