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

Mode of Transmission:

• Ingestion of contaminated food and water
• Directly from faeces contaminated fingers
• Occasionally by droplet infection
• Children below 5 years are mostly affected

Incubation period: 2-3 days 

Pathogenesis:

• Rota virus replicates in enterocyte near the tip of villi destroying enterocytes
• Viral encoded toxin: early profuse, secretory diarrhea is caused by enterotoxin, NSP4.
• Disruption of mature villus cells of small intestine intestinal epithelium due to virus replication
• Histologic changes of enterocytes that triggers enteric nervous system, intestinal secretion and immune response
• The acute infection and diarrhea normally resolves within 7 days in immunocompetent hosts. 

Clinical symptoms:

1. Local infection:

• Acute Gastroenteritis, severe in case of infants aged 6-24 months.
• Infected Infants are unable to digest milk due to lactase deficiency caused by destruction of enterocytes
• Diarrhoea, nausea and vomiting
• Malabsorption of Na+, water, and disaccharides
• Symptoms of Dehydration: decrease in urination, dry mouth and throat and feeling dizzy when standing up.

2. Systemic infection:

• High grade Fever
• Lymphocytosis and transient neutropenia.

3. Complication:

• Febrile Convulsion in small children
• Severe dehydration, hypotonia and shock 

Laboratory diagnosis:

Specimen: faeces in early infection,

• Viral antigen detection: solid phase agglutination, ELISA
• Electron microscopy
• EIA (enzyme immune assay): it is sensitive to detect virus in stool
• Dip stick/ rapid test
• PCR: For genotyping of Rotavirus
• Virus culture: No cell line culture 

Treatment:

• Oral rehydration
• Other supportive rehydration therapy to control loss of water and electrolytes

Vaccine:

• Genetic reassortment  vaccine is best vaccine for rotavirus.
• Two Oral rotavirus vaccines are currently licensed for use in infants
  1. RV5 is given in 3 doses at ages 2 months, 4 months, and 6 months
  2. RV1 is given in 2 doses at ages 2 months and 4 months
•  Contraindicated in:
  • SCID
  • Intussusception
  • Allergy

Prevention and control:

• Sanitation
• Waste water treatment
• Health professional should wash their hands with soap and water before and after patient contact.