High prevalence and morbidity of Schistosoma mansoni along the Albert Nile in Uganda

Abstract

An epidemiological cross sectional study of Schistosoma mansoni was conducted in two hyper endemic fishing villages of Rhino Camp and Obongi both in West Nile district in northern Uganda in 1991 and 1992. People with various water contacts were registered. A small group of civil servants and clergies with less water contact in the river Nile were studied for control of infection and morbidity. An overall prevalence of 81.5% of the 1367 people studied in both fishing villages of Rhino Camp and Obongi were excreting from 100 to > or = 500 Schistosoma mansoni eggs per gram (epg). 253 18.5% did not have Schistosoma mansoni eggs in their faeces. The influence of socioeconomic factors on infections in the study population was high among poorer illiterates who have frequent water contacts activities with River Nile. The sonomorphological abnormalities of periportal thickening (PT) due to Schistosoma mansoni were performed using ultrasound. 664 patients were found to have various stages of (PT stages 0, I, II and III). A total of 703 (51.4%) patients did not have any periportal thickening (PT 0) in their livers despite the fact that 450 (32.9%) of them had Schistosoma. mansoni eggs in their faeces. The gravities of schistosomiasis in the two villages were similar showing greater morbidity in the younger adults.

Fig 1

Percentage comparison of intesity of egg excretion and periportal fibrosis grades in Rhino Camp and Obongi (n=1367) Percentage prevalence of Schistosoma mansoni infections in Rhino-Camp and Obongi in northern Uganda among people with different intensity of egg excretions and grade of periportal fibrosis of the liver. Percentage of infections, and percentage of different grades of periportal thickening.

Fig 2

Percentage of egg excertion per gram of faeces in specific age group Percentage prevalence of different level of egg excretion of Schistosoma mansoni in different age groups in Rhino Camp and Obongi in north Uganda. Number of infected individuals with different level of egg excretions in specific age groups. 0–5 years (◇) n= 57; 6–10 years (□), n=130; 11–20years, (△) n=497; 21–30years (Î) n=245; and > 30 year(?)n=438.

Fig 3

Percentage comparison of S.mansoni infection in Rhino Camp and Obongi Percentage comparison of Schistosoma mansoni infections in different categories of egg excretion at Rhino Camp and Obongi in northern Uganda. Percentage of infection in Rhino Camp n=636 (◇) and Obongi n= 731 (Î)

Fig 4

Percentage comparison of different grades of periportal thickening in Rhino Camp and Obongi Percentage comparison of periportal thickening at Rhino Camp and Obongi in northern Uganda. Periportal thickening in Rhino Camp, (◇) n=636; periportal thickening in Obongi, (O) n=731

Fig 5

Relationship between different levels of egg excretion and grade of periportal thickening Relationship between different levels of intensity of infections and grades of periportal fibrosis (n= 1367) patients in Rhino Camp and Obongi in West Nile Province, northern Uganda. Number of individuals in different level of egg excretion; negative, 0 (?) n =253; 1–99 epg (?) n= 602; 100–499epg (?) n=371; ? 500 epg. (|) n=141.

Fig 6

Periportal thickening in different groups of patients studied Periportal thickening in different categories of individuals studied at Rhino Camp and Obongi in north Uganda, (n=664). Periportal thickening, (PT); school pupils, (?); civil servants, (?); volunteers, (?); and fishermen, (?).

Fig 7

Periportal thickening in different age groups Periportal thickening in different age groups in years of 1367 subjects in Rhino Camp and Obongi, north Uganda. Periportal thickening, (PT) age group, 1–5 (|); age group, 6–10 (?); age group