Chapter 3 – Epidemiology of infectious diseases (Parasites & Scabies)
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“” Amebiasis “”
Identification
A protozoan parasite (Entamoeba histolytica) infection that exist in 2 forms:
1.Cyst 2.Trophozoite. The parasite may be commensal or invasive that produce
intestinal & extra intestinal disease
Clinical presentation of intestinal type:
- Either acute and fulminating i.e fever,chills,bloody or mucous diarrhea and this may be
missed by ulcerative colitis and ca colon - or presented with mild abdominal discomfort
(diarrhea alternated by a period of constipation)
.
Epidemiology
The
causative agent
Entamoeba histolytica higher incidence occurs in areas of poor
sanitation in tropics mental institutions and homosexual males. In areas with good
sanitations, amebic infections tend to cluster in households and institutions
.
Reservoir:
Only humans, usually a chronically ill or asymptomatic cyst passer
Mode of transmission
Mainly through ingestion of fecally contaminated food or water containing amebic cyst.
transmission may occur by ano-oral contact with chronically ill or asymptomatic cyst passer.
Incubation period:
Variable, from a few days to several months or years, commonly 2 – 4 weeks.
Period of communicability
During which Entamoeba ahistolytica cyst are pased, which may continue for years.
Preventive and control measures
Preventive measures:
1) Sanitary disposal of human feces .
2) Safe water supply by proper chlorination.
3) Education of general public in personal hygiene and in hand washing after defication.
4) Health supervision of food handlers.
5) Thorough washing of fruits and vegetables with potable water and keep them dry.
6) Educate high risky groups to avoid sexual practices that may permit fecal-oral transmission.
7) Treat known carriers.
Control the patient, contacts & the immediate environment:
1) Report of the cases to local health authorities.
2) Precautions in handling feces & contaminated clothes & bed sheets in hospitalized cases.
3) Exclusion of carriers from food handling.
4) Concurrent disinfection of disposed feces.
5) Contact investigation to get the sort of Infection as house hold members.
6) Specific treatment is one of important measures in the control of this disease.