COMMUNITY HEALTH NURSING I, EPIDEMIOLOGY OF COMMUNICABLE DISEASES, AMOEBIASIS, UNIT IV, II YEAR BSC NURSING STUDENT

1. AMOEBIASIS
Prepared By
Krupa Mathew.M
Associate Professor

2. AMOEBIASIS
• The term amoebiasis has been identified by WHO as
the condition of harboring the protozoan parasite
Entamoeba histolytica with or without clinical
manifestations.

3. TYPES OF AMOEBIASIS
The symptomatic group has been further subdivided into
• Intestinal amoebiasis : The intestinal disease varies
from mild abdominal discomfort and diarrhoea to acute
fulminating dysentery. Only a small percentage of those
having intestinal infection will develop invasive
amoebiasis.
• Extraintestinal amoebiasis : Includes involvement of
liver (liver abscess), lungs, brain, spleen, skin, etc.
• Amoebiasis is a potentially lethal disease. It carries
substantial morbidity and mortality.

4. INCIDENCE
• Amoebiasis affects about 15 per cent of
the Indian population.
• It has been reported throughout India.
The prevalence rate is about 15%
ranging from 3.6 to 47.4 per cent in
different areas

5. EPIDEMIOLOGICAL DETERMINANTS
AGENT
ENVIRONMENT
HOST

6. AGENT FACTORS
AGENT:
Entamoeba histolytica.
RESERVOIR OF INFECTION:
Man.
SOURCE OF INFECTION:
Faeces containing the cysts.
PERIOD OF COMMUNICABILTY:
As long as cysts are excreted, the period may be
several years , if cases are unrecognized and
untreated.

7. HOST FACTORS
• May occur at any age.
• No sex or racial difference.
• Frequently an household infection.
• Cell mediated immunity plays a major role in
controlling the recurrence of invasive
amoebiasis.

8. ENVIRONMENTAL FACTORS
• Poor sanitation.
• Socio economic status .
• Less chance for climate.
• Use of night soil for agricultural purposes favors
the spread of infection.
• Wet-dry seasons.
• Rainy season.

9. LIFE CYCLE

10. LIFE CYCLE
E. histolytica exists in two forms
1. Vegetative (trophozoite)
2. Cystic forms.
Trophozoites dwell in the colon where they multiply and Encyst.
The cysts are excreted in stool
(The cysts are infective to man and remain viable and
infective for several days in faeces, water, sewage and soil in
the presence of moisture and low temperature.)

11. CONT’D LIFE CYCLE
Ingested cysts release trophozoites which colonize in
the large intestine. Some trophozoites invade the
bowel and cause ulceration, mainly in the caecum
and ascending colon; then in the rectum and
sigmoid
Some may enter a vein and reach the liver and other
organs
They dwell in Colon, again the cycle starts

12. CHARACTERISTICS
• The trophozoites are short-lived outside
the human body; they are not important in
the transmission of the disease.
• The cysts are not affected by chlorine, but
they are readily killed if dried, heated
(to about 55 deg C) or frozen.

13. MODE OF TRANSMISSION
• Fecal-oral route: Vegetables, especially those
eaten raw, from fields irrigated with sewage
polluted water can readily convey infection.
• Sexual transmission: By oral-rectal contact in
Homosexuals
• Vectors: Flies, cockroaches and rodents, carrying
cyst and contaminating food and drink.

14. SYMPTOMS
• Abdominal cramps.
• Diarrhea: Passage of 3 to 8 semi formed stools per day,
or passage of soft stools with mucus and occasional
blood.
• Fatigue.
• Excessive gas.
• Rectal pain while having a bowel movement (tenesmus)
• Unintentional weight loss.

15. INCUBATION PERIOD
About 2 to 4 weeks or longer.

16. PREVENTION AND CONTROL
•Primary prevention.
•Secondary prevention.

17. PRIMARY PREVENTION
• Sanitation.
• Water supply.
• Food hygiene.
• Health education.

19. SANITATION
• Safe disposal of human excreta
• washing hands after defecation and before eating is a
crucial factor
• With the cooperation of the local community, the
sanitary systems should be selected and constructed.

20. WATER SUPPLY
• The protection of water supplies against faecal
contamination.
• The cysts are not killed by chlorine in amounts used
for water disinfection. Sand filters are quite effective
in removing amoebic cysts. Therefore water filtration
and boiling are more effective than chemical
treatment of water against amoebiasis.

21. FOOD HYGIENE
• Uncooked vegetables and fruits can be disinfected
with aqueous solution of acetic acid (5-10 per cent)
or full strength vinegar.
• Thorough washing in running water will remove
amoebic cysts from fruits and vegetables.
• Since food handlers are major transmitters of
amoebiasis, they should be periodically examined,
treated and educated in food hygiene practices such
as hand washing.

22. HEALTH EDUCATION
• Emphasis on Hand washing
• Washing of vegetables and fruits
• Wash well if you eat raw vegetable
• Avoid open air defecation
• Drink water from filtered source / better drink
hot water

23. SECONDARY PREVENTION
•Early Diagnosis
•Treatment.

24. EARLY DIAGNOSIS
• Demonstration of trophozoites containing red cells is
diagnostic. They are most readily seen in fresh mucus
passed per rectum.
• The absence of pus cells in the stool may be helpful
in the differential diagnosis with shigellosis.
• Indirect haemagglutination test is regarded as the
most sensitive serological test.
• Newer techniques include Immuno-electrophoresis
ELISA technique are also used in laboratory

25. TREATMENT
Symptomatic Cases.
Asymptomatic Cases.

26. SYMPTOMATIC CASES
• Treat at health centre level.
• Give Metronidazole orally.
• Clinical response in 48 hours may confirm the
suspected cases.
• Dose-30 mg/kg of body weight/day.
• Divided into 3 doses after meals, for 8-10 days.
• Tinidazole can be used instead of metronidazole.
• Suspected cases of liver abscess should be referred to
the nearest hospital.

27. ASYMPTOMATIC CASES
• Oral diodohyroxyquin,650 mg TDS (adults),
• 30-40 mg/kg of body weight /day (children)
for 20 days
OR
• Oral diloxanide furoate,500 mg TDS for 10
days (adults).

28. CHEMOPROPHYLAXIS
• At present there is no acceptable
chemoprophylaxis for amoebiasis.
• Mass examination and treatment cannot
be considered a solution for the control of
amoebiasis.