epidemiology and prevention of acute diarrhoeal diseases

1. ACUTE DIARRHOEAL DISEASES
Dr. Vishwajeet M. Chavan
Asst. Professor SPM
vishwajeetdada@gmail.com

2. Diarrhoea
Abnormal increase in-
stool liquidity
stool frequency
stool quantity
Under nutrition , recent measles (in case of under 5yrs)
are associated with increased incidence, severity or
duration of diarrhoea.

3. Risk factors
• Bottle fed babies have more chances to develop
diarrhoea because of unclean bottles
• Houseflies bring germs to uncovered food
• Drinking contaminated water/ food
• Through milk, unclean hands & unclean utensils

4. Acute diarrhoea
• Caused due to infections by a wide variety of micro -
organisms such as bacteria, viruses, protozoa &
helminthes or due to toxins produced by them, is an
inflammation of G.I. tract.
• Both the stomach & small intestine are involved.
• Characterized by the presence of vomiting & diarrhoea,
the latter being prominent in cases of bacterial origin.

5. Epidemiology ( A.G.E.)
• Magnitude of the problem Acute gastroenteritis is a
major cause of morbidity and mortality, especially in
children under 5 yrs of age.
• World wide more than a billion cases of gastroenteritis,
majority being from developing world, are reported
every year.
• In India incidence rate ranges from 1 to 3 episodes per
child per year.

6. • In slum areas of major cities incidence found is 7
episodes/child/year
• National Family Health Survey-4 (2015-16) showed that
9% children under 5yrs of age suffered from diarrhoea in
preceding 2wks

7. Depending on the presence of blood in stool, these agents
are classified as-
(A) Causes of acute gastroenteritis without blood in stool
() Viruses : Rotavirus, Astrovirus, Norwalk group of virus,
Enteric adenovirus, Hepatitis A
() Bacteria : Shigella, Salmonella infection, Enterotoxigenic E.
coli (ETEC), Enteropathogenic E. coli (EPEC),
Enteroaggregative E. coli (EAVC), Staph aureus, V. Cholera,
Clostridium perfringens, C. difficile, Bacillus cereus and B.
subtilis

8. (iii) Protozoa : Giardiasis, Cryptosporidiosis, Cyclospora
cayetenesis
(iv) Helminths : Strongyloidiasis

9. (B) Causes of acute gastroenteritis with blood in stool
() Bacteria : Shigella, Enterohaemorrhagic E.coli,
Campylobacter jejuni, Yersinia entercolitis
() Protozoa : Entamoeba histolytica, Balantidium coli
enterocolitis
() Helminths : Massive trichuris infection, Schistosoma
mansoni, S. japonicum Reservoir and source of infection :
Man is the principal reservoir of the infections.

10. Agent factors
• Contaminated food or water serves as the principal
source of infection.
• The causative agents are significantly different from each
other as far as the mode of transmission and virulence
is concerned.
• Vibrio and S. typhi are spread by water, others like Staph.
aureus and C. perfringens are spread by food.

11. • Some like salmonella non - typhi, which multiply in
food & V. cholerae have the potential of causing
outbreaks.
• C. jejuni and E. histolytica produce sporadic diseases.
Patients with acute amoebic dysentery pose only limited
danger as it’s fragile nature.
• Asymptomatic or mild cases excreting cystic forms of E.
histolytica on the other hand are important reservoir of
infection.

12. Host factors :
• Man has no natural immunity against these organisms.
Both sexes are equally susceptible.
• Children and the old-aged suffer more.
• Transient immunity develops against the specific strain of
some of the organisms like Shigella.
• Host differences such as race and age have been
described as affect susceptibility of individuals to
infection

13. • Intestinal motility plays an important role in providing
protection against the infection.
• Increased gut motility associated with diarrhoea is a
highly effective defense mechanism.
• Incidence is highest at the time of weaning i.e. between 6
- 11 months

14. Environmental factors :
• Non - availability, inadequacy or lack of access to clean
drinking water.
• Inadequate disposal of fecal waste and poor hygiene and
sanitation increases the likelihood of these diseases.
Travelers travelling from developed countries to
developing countries usually contract disease agents

15. • Diarrhoeal diseases follow a distinct seasonal pattern.
• Rotavirus diarrhoea tends to occur throughout the year,
increasing in frequency during the drier, cool months,
whereas bacterial diarrhoeas tend to peak during the
warmer, rainy season.

16. Mode of Transmission :
• Infection by all organisms is by ingestion of
contaminated food or drink i.e. fecal- oral route.
• Individuals primarily responsible for transmission are
those with poor personal hygiene & those who fail to
cleanse contaminated hands and carry organisms under
their fingernails after defecation.

17. • Contaminated water is believed to play a major role in
the transmission of amoebiasis.
• Amoebic cysts are not killed by chlorine in amounts
normally added for water disinfection.
• Water can be rendered free from amoeba-cyst only by
sand filtration.

18. • Milk & food are contaminated by infected water or by
the hands of a carriers or case.
• Cockroaches also can act as vehicles for contamination
of crockery, cutlery, kitchen utensils.
• Dust containing cysts in case of Entamoeba histolytica
also responsible for transmision of agent
• Vegetables from fields irrigated with polluted water or
especially those cultivated with raw sewage as practiced
in improper sewage farming are liable to carry infection.

19. Incubation period and Period of
communicability :
Several hours as in case of bacillary dysentery to (2 to 4
weeks), but can be prolonged to several months, as in
case of amoebic dysentery.
Diarrhoea and bacillary dysentery cases are most
infective during the clinical illness.
A case of amoebic dysentery is infective mostly during
the non - clinical period between the remissions of
clinical attack, because it is the cystic stage of amoeba
which is infective.

21. Clinical Features
• Diarrhoea, vomiting occasionally both.
• The frequency and consistency of the stool depends on
the causative organism.
• Conventionally diarrhoea is the passage of 3 or more
loose or liquid stools per day, or more frequently than is
normal for the individual. Acute diarrhoea is an attack of
sudden onset which usually lasts for 3 – 7 days

22. • Most cases of infectious diarrhoea are acute.
• Usually acute gastroenteritis is not associated with
constitutional symptoms
• But abdominal cramps may be present in some cases
especially with dysentery.
• Fever may be occasionally present especially in
salmonella and shigella infections.
• In some cases, due to excessive loss of fluid, features of
dehydration like thirst, restlessness or irritable behavior,
dry mucosa, decreased skin turgor and sunken eyes, may
be present.

23. • Rotavirus infection occurs worldwide & it is estimated to
cause 20% of childhood(under 5yrs of age) deaths.
• Children less than 3 years of age are most commonly
infected.
• Vomiting is an early feature and fever is common.
• Diarrhoea is usually watery and large in volume.
• Colicky abdominal pain, ill defined tenderness and
exaggerated bowel sounds are common

24. Prevention
• Immunization
• Better MCH practices-
Maternal nutrition
Child nutrtion
– Breast feeding promotion
– Appropriate weaning practices
– Supplementary feeding
– Vit. A supplementation

25. Two live, oral, attenuated rotavirus vaccines licensed in
India since 2006 for prevention of Rotavirus infection…
1. Rotarix: 2 oral doses (1st-6wks 2nd -12wks)
2. Rota Teq: 3 oral doses at ages 2, 4 & 6 months

26. 20 mg per day of Zn supplementation for 14 days
starting as early as possible after onset
10 mg per day for infants 2-6 months
WHO/UNICEF Joint statement (2001),
IAP 2003,
GOI 2007
Recommendations for use of zinc in clinical
management of acute diarrhoea :

27. Outbreak prevention
(a) Isolation :
This will break the chain of transmission.
(b) Rehydration :
All cases must be given reduced osmolarityORS liberally.
(c) Breastfeeding : Because of its protective qualities,
breastfeeding must be continued for sick children.
(d) Safe drinking water :
Water supplies should be adequately chlorinated.
(e) Food safety : Food hygiene should be made stricter.
Adequate storage facility for storage of food (both cooked and
uncooked)and adequate water for cleaning and cooking must be
provided.All crockery and cutlery must be adequately cleaned
before use.Milk should be boiled before consumption.

28. WHO Safety guidelines for food
• Cook raw food thoroughly
• Eat cooked food immediately
• Prepare food for only one meal
• Avoid contact between raw food & cooked food
• Choose food processed for safety
• Wash hands repeatedly
• keep food preparation premises meticulously clean
• Use safe water
• Be cautious with food purchased outside
• Breast-feed infants & babies