Viral enteritis (Rotaviruses) Flashcards
What is meant by viral gastroenteritis?
- It is the inflammation of the lining of the stomach, S.I & L.I
- Viral gastroenteritis causes millions of diarrheal cases each year
- Most people recover without complications unless they become dehydrated
- After URT infections, viral gastroenteritis is the second most common viral illness
- Rotavirus is the main virus, and it is responsible for half a million deaths each year
What are the viruses that are associated with gastroenteritis?
- Major viruses:
1) Rotavirus (half of the cases)
2) Enteric adenoviruses
3) Norovirus (norwalk-like viruses, calicivirus, astrovirus)
- Minor viruses:
1) Coronaviruses
2) Parvoviruses
3) Pestiviruses
4) Toroviruses
What is rotavirus?
- “Rota” because it looks like a wheel
- It is a virus that infects the bowels, causing severe inflammation of the stomach and bowels (gastroenteritis)
- It is the most common cause of severe diarrhea among infants and children aged 6 months - 2 years
- It is a member of the reoviridae family, containing a double-stranded RNA (ds-segmented RNA) which is enclosed by a double-shelled outer layer (capsid)
- It has a short incubation period of 1-3 days
How is the rotavirus transmitted?
- It enters through the mouth and replicates in the epithelium of the S.I
- Animals can transmit the disease to humans via contaminated soil and food
- The primary mode of transmission is the fecal-oral route, usually through direct contact between people
- Ingestion of contaminated water or food
- Touching contaminated surfaces
- FYI: The virus is killed by the ethanol and formalin
What are the complications of an infection with rotavirus?
Dehydration may result, tand his can be severe and life threatening in young children
What are the characteristics of rotavirus?
- Wheel-like appearance
- Non-enveloped virus
- Double shelled (double stranded RNA), enclosed within an RNA genome consisting of 11 segments of RNA which codes for 12 proteins
- Its nucleic acid is surrounded by two layers (an intermediate layer which consists of the major capsid protein “VP6”, and an outer layer that contains an attachment protein “VP4” and glycoprotein “VP7”
- They are stable in temperatures of 50 degrees, 3-9 pH
What are the different groups of rotavirus?
- There have been seven serological groups identified (A-G), and only A, B, and C infects humans
1) Grop A: Has subtypes 1-4, which can infect humans and animals (monkey, calf, and mouse)
2) Group B: Infects humans, pigs, and rats, caused extensive outbreaks in China in the past decade
3) Group C: Infects pigs
- Group A is the most common
Describe the epidemiology of rotavirus
1) Millions are affected, and 600K- 850K deaths per year
2) It is a major cause of diarrhea-associated hospitalizations
3) Group A is the most common
4) Group B (adult + china) mainly causes outbreaks in adults in China
5) Group C is responsible for sporadic cases of diarrhea in infants around the world
What are the signs and symptoms of rotavirus infection?
1) Inflammation of the stomach and intestines (gastroenteritis)
2) Severe diarrhea in infants and children (watery, green or yellow diarrhea, but it does not contain mucus nor blood)
3) Fever
4) Vomiting (short duration, but can lead to dehydration)
5) Abdominal pain
6) Life-threatening dehydration
7) Viraemia
How to diagnose rotavirus infections?
1) Electron microscopy (from stool)
2) Enzyme-linked immunosorbent assay (ELISA) detection of VP6 group A-specific antigen in stool
3) Passive particle agglutination test (PPAT), based on antigen-antibody interaction
4) Polyacrylamide gel electrophoresis (PAGE), based on antigen-antibody interaction
5) Reverse transcription-polymerase chain reaction (RT-PCR), for detection of rotavirus in extraintestinal tissues
- FYI: Methods like ELISA, PCR, etc. are more commonly used for diagnosis
What are the preventative measures of rotavirus infection?
1) Hand-washing
2) Sanitation
3) Drinking only clean water
4) Rotavirus vaccination (for children under 2 years, Live oral fascinated vaccines like RotaTeg (3-doses 2, 4, & 6 months) and Rotarix (2 doses 2 & 4 months)
What is the treatment for rotavirus?
1) For healthy ppl with good immunity, rota is self-limited (just give oral rehydration therapy)
2) Zinc supplements
3) Probiotics (proved to reduce the duration of rotavirus infection)
