Foci of Schistosomiasis mekongi, Northern Cambodia: II. Distribution of infection and morbidity

• Published in: Tropical medicine & international health 1999-10, Vol.4 (10), p.674-685
• Main Authors: Stich, A. H. R., Biays, S., Odermatt, P., Men, Chan, Saem, Cheam, Sokha, Kiev, Ly, Chuong Seng, Legros, P., Philips, M., Lormand, J.‐D., Tanner, M.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Biological and medical sciences; Cambodia; Cambodia - epidemiology; Child; Child, Preschool; Diseases caused by trematodes; epidemiology; Female; Health Surveys; Helminthic diseases; Humans; Infant; Infectious diseases; Male; Medical sciences; Mekong River; Middle Aged; Morbidity; Parasitic diseases; Schistosoma; Schistosoma mekongi; Schistosomiases; schistosomiasis; Schistosomiasis - epidemiology; Schistosomiasis - mortality; Schistosomiasis - parasitology; Schistosomiasis - physiopathology; Tropical medicine
• ISSN: 1360-2276; 1365-3156
• DOI: 10.1046/j.1365-3156.1999.00474.x

Summary In the province of Kracheh, in Northern Cambodia, a baseline epidemiological survey on Schistosoma mekongi was conducted along the Mekong River between December 1994 and April 1995. The results of household surveys of highly affected villages of the East and the West bank of the river and of school surveys in 20 primary schools are presented. In household surveys 1396 people were examined. An overall prevalence of infection of 49.3% was detected by a single stool examination with the Kato‐Katz technique. The overall intensity of infection was 118.2 eggs per gram of stool (epg). There was no difference between the population of the east and west shore of the Mekong for prevalence (P = 0.3) or intensity (P = 0.9) of infection. Severe morbidity was very frequent. Hepatomegaly of the left lobe was detected in 48.7% of the population. Splenomegaly was seen in 26.8% of the study participants. Visible diverted circulation was found in 7.2% of the population, and ascites in 0.1%. Significantly more hepatomegaly (P = 0.001), splenomegaly (P = 0.001) and patients with diverted circulation (P = 0.001) were present on the west bank of the Mekong. The age group of 10–14 years was most affected. The prevalence of infection in this group was 71.8% and 71.9% in the population of the West and East of the Mekong, respectively. The intensity of infection was 172.4 and 194.2 epg on the West and the East bank, respectively. In the peak age group hepatomegaly reached a prevalence of 88.1% on the west and 82.8% on the east bank. In the 20 schools 2391 children aged 6–16 years were examined. The overall prevalence of infection was 40.0%, ranging from 7.7% to 72.9% per school. The overalls mean intensity of infection was 110.1 epg (range by school: 26.7–187.5 epg). Both prevalence (P = 0.001) and intensity of infection (P = 0.001) were significantly higher in schools on the east side of the Mekong. Hepatomegaly (55.2%), splenomegaly (23.6%), diverted circulation (4.1%), ascites (0.5%), reported blood (26.7%) and mucus (24.3%) were very frequent. Hepatomegaly (P = 0.001), splenomegaly (P = 0.001), diverted circulation (P = 0.001) and blood in stool (P = 0.001) were significantly more frequent in schools of the east side of the Mekong. Boys suffered more frequently from splenomegaly (P = 0.05), ascites (P = 0.05) and bloody stools (P = 0.004) than girls. No difference in sex was found for the prevalence and intensity of infection and prevalence of hepatomegaly. On the school