Rotavirus: Pathogenesis, Clinical symptoms, laboratory diagnosis, and Treatment

Rota virus

Rotavirus is the major cause of diarrhea in infants and children under the age of 2.

The replicates in the intestinal mucosa, producing a profuse, watery, non-bloody diarrhea, often coupled with nausea and vomiting. Transmission is by the fecal-oral route.

Ans. is b i.e., Rota B can be grown in cell culture

. “Rota viruses are fastidious agents to culture. Most group A human rotaviruses can be cultivated if pretreated with the proteolytic enzyme trypsin and if low level of trypsin are included in the tissue culture medium. Very few non group A Rotavirus strains have been cultivated.”

. From this the more appropriate choice for answer would be “Rota B can be grown in cell culture “

There are 3 group of Rota virus

.  Group A Rota virus         – Most important cause of endemic severe diarrhoeal illness in infants and young children.

.  Group B Rota virus         – Outbreak of diarrheal illness in adults and children.

. Group C Rota virus         – Sporadic cases and occasional outbreaks of diarrhoea in children

Ans. is b i.e., Rotavirus

Enterotoxin

– A non-structural `rotavirus protein, NSP4, functions as an enterotoxin and contributes to secretory diarrhea.

1. Activation of enteric nervous system

– Rotavirus may evoke fluid secretion through activation of enteric nervous system in the intestinal wall.

Ans. is ‘c’ i.e., Immunofluorescence antigen is stool 

Laboratory diagnosis

• In Rotavirus diarrhoea, large no. of viruses are shed in faeces (at the peak of the disease, as many as 10″ virus particles can be detected per ml of feces). These viruses can be easily detected by the following methods:

.  Enzyme immunoassay (ELISA)

–  It offers approximately 90% specificity & sensitivity for detection of virus in stools.

. Latex agglutination

. Immune electron microscopy

• Viral shedding detectable by these methods usually subsides within a week.
• Virus in stools can be detected for longer periods by using techniques for detecting viral RNAs, such as PCR, Gel electrophoresis, probe hybridization.
• Culture of Rotavirus is not used for routine diagnosis as they are fastidious organisms (require strict pre-requisites for growth)

.  Serological diagnosis

.  The diagnosis of Rotavirus can also be made by detection of antibodies in the serum

. The test commonly employed for serological diagnosis is ELISA.

From the above given explanation, none of the given option appear to be correct. But option ‘a’, ‘b’ & ‘d’ can be easily ruled out as

–  Antibodies are detected in serum, not in stool.

– Culture of Rotavirus is not used as its extremely difficult.

We are left with option ‘c’ i.e., immunofluorescence. In support of this option we quote text from Jawetz “Rotavirus possess common antigens located on most if not all the structural proteins these can be detected by immunofluorescence. ELISA and immunoelectron microscopy.”

Ans. is ‘a’ i.e., Antigen is stool by ELISA

Because Rotavirus is shed in large amounts is stool, detection is relatively easy. Most commonly used are commercial immunoassays to detect rotavirus antigen in fecal specimen.

Ans. is ‘a’ i.e., Antigen in stool 

Ans. is ‘c’ i.e., Genetic reassortment 

The segmented genome of rotavirus allows genetic reassortment during coinfection – a property that may play a role in viral evolution and has been utilized in the development of reassortment animal – human rotavirus – based vaccines.

Ans. is ‘a’ i.e., Rotavirus

Ans. is ‘b’ i.e., Infantile diarrhea

Ans. is ‘a’ i.e., Rotavirus

In 1999, a highly efficiaous rotavirus vaccine, Rotashield licenced in United States, was withdrawn from the market after less than one year because of its association with intussuseption.

Ans. is ‘c’ i.e., Rotavirus

“Rotaviruses are recognized as the most common cause of diarrhea! disease in infants and children”

– Ananthnarayan Causes of acute diarrhea in children

• Virus                                                              
• Bacteria                                           
• Parasites
• Rota virus                       
• Calcivirus           
• ETEC                
• Salmonella                          
• E. histolytica
• Norwalk virus               
• Astrovirus         
• EIEC                 
• Campylobacter                  
• Giardia
• Adenovirus       
• Shigella              
• Aeromonas hydrophilia
• Cryptosporidium

Ans. is ‘b’ i.e., Rotavirus

“In India Rotavirus and enterotoxogenic E.coli account for nearly half of the total diarrhoeal episodes among children”.

Ans. is ‘d ‘i.e., All of the above