Amoebiasis and ascariasis

1. AMOEBIASIS AND
ASCARIASIS
DR. MARIYAM KHWAJA

2. AMOEBIASIS
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3. AMOEBIASIS : Introduction
 Definition: Harbouring Entamoeba histolytica with or
without clinical manifestation (WHO)
 Symptomatic:< 10%, can be intestinal and extra intestinal
 Intestinal: mild abdominal discomfort, diarrhea to acute fulminating dysentery
 Extra intestinal: involvement of liver, lungs brain , spleen
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4. AMOEBIASIS : Problem Statement
 WORLD:
 Worldwide distribution
 Major health problem in China, South East and West Asia and Latin America
 500 million people carry E. histolytica, 1/10th – invasive amoebiasis
 Prevalence: 2-60%
 In areas of high prevalence, occurs in endemic form: high levels of transmission and
constant reinfection
 Epidemic water borne infections: heavy contamination of drinking water supply
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5. AMOEBIASIS : Problem Statement
 INDIA:
 Affects 15% of Indian population
 Prevalence rate: 15% (3.6-47.4)
 Due to variations in diagnostic criteria and to technical difficulties in
establishing a correct diagnosis and lack of sampling criteria
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6. AMOEBIASIS : Epidemiological Determinants
 AGENT FACTORS
 Agent: Pathogenic strains of E. histolytica
2 forms: Vegetative(trophozoite) and cystic forms
 Trophozoite: dwell in colon and multiply and encyst, some
invade and cause ulceration
Cysts : infective to man and remain viable for several days.
Reservoir of Infection: Man (feaces containing cysts)
Period of communicability: as long as cysts are excreted
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7. AMOEBIASIS : Epidemiological Determinants
 HOST FACTORS:
 Any Age, no sex or racial difference
 Household infection
 ENVIRONMENTAL FACTORS
 Poor sanitation and socio economic status
 Use of night soil for agricultural purposes favours the spread of
disease
 Epidemic: sewage seepage into water supply
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8. AMOEBIASIS : Mode of Transmission
 Fecal oral Route:
 Contaminated food or water
 Vegetables: eaten raw, from fields irrigated with sewage polluted
water
 Viable cysts: hands and under finger nails
 Sexual Contact: Oral rectal contact
 Vectors: flies, cockroach, rodents
 INCUBATION PERIOD: 2-4 weeks
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9. AMOEBIASIS : Prevention and Control
SANITATION
• Safe disposal of Human Excreta
• Hand washing
WATER
SUPPLY
• Protection of water supplies against fecal contamination
• Water filtration and Boiling are more effective
FOOD
HYGIENE
• Protection of food and drink against fecal contamination
• Uncooked vegetables and fruits: washed with acetic
acid, vinegar
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10. AMOEBIASIS : Prevention and Control
EARLY
DIAGNOSIS
• Trophozoites containing red cells: diagnostic (most readily seen in fresh mucus passed
p/r
• Serological : negative in intestinal amoebiasis
• IHA: most sensitive
• Others: CIE<,ELISA
TREATMENT
• Symptomatic Cases: Metronidazole 30 mg/kg TDS for 8-10 days
• Asymptomatic: In endemic areas-do not treat
• Non endemic areas or if carrier is a food handler: Oral diiodohyroxyquin for 20 days or
oral diloxanide furoate
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11. SOIL TRANSMITTED
HELMINTHIASIS
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12. SOIL TRANSMITTED HELMINTHIASIS
 Group of parasitic diseases in humans caused by intestinal roundworms (ascariais),
hookworms (Necator americanus and Ancylostoma duodenale) and whipworm (Trichuris
trichuria)
 Affects 24% of world’s population
 Widely common in tropical and subtropical areas
 One of NEGLECTED TROPICAL DISEASES
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13. STH: Mode of Transmission
 Transmitted by eggs that are passed in faeces of infected people
 Lack of sanitation eggs contaminate soil
 Attached to vegetables and salads are ingested when vegetables are
not carefully cooked, washed or peeled
 Ingested from contaminated water source
 Ingested by children who play in soil and put their hands in mouth
without washing them
 Larvae of hookworm : walking barefoot
 NO DIRECT PERSON TO PERSON TRANSMISSION or INFECTION
FROM FRESH FEACES
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14. ASCARIASIS
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15. ASCARIASIS: Introduction
 Infection of intestinal tract caused by adult Ascaris lumbricoides
 Clinically manifested by nausea, abdominal pain and cough.
 Live worms are passed in stools or vomitus
 Occassionally: obstruction or migrate into peritoneal cavity
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16. ASCARIASIS: Geographic distribution and prevalence
 Cosmopolitan in distribution
 Most common helminthic infection
 1 billion people are infected worldwide
annually
 20,000 deaths
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17. ASCARIASIS: Epidemiological Features
 AGENT : Ascaris lumbricoides
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18. ASCARIASIS: Epidemiological Features
 RESEVOIR OF INFECTION: Man
 INFECTIVE MATERIAL: Faeces containing fertilized eggs
 HOST: Infection rates are high in children, adults seem to acquire some
resistance
 ENVIRONMENT:
 Low temp: inhibits development of eggs
 Clay soil favors development of ascariasis eggs
 HUMAN HABITS: Open air defecation
 PERIOD OF COMMUNICABILITY: Until all fertile females are
destroyed and stools are negative
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19. ASCARIASIS: Clinical Features
 INCUBATION PERIOD: 18 days to several weeks
 SYMPTOMS:
 Light infection: no symptoms
 Heavy Infection: (> 50,000 eggs per gram of feaces): Diarrhea,
abdominal pain, general malaise, weakness, impaired cognitive and
physical development
 Fever, cough, sputum formation, asthma, skin rash, eosinophilia
 Volvulus, intestinal obstruction or intussusception, bowel perforation
blocking of common bile duct
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