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

Citation
Ahr. Stich et al., Foci of Schistosomiasis mekongi, Northern Cambodia: II. Distribution of infection and morbidity, TR MED I H, 4(10), 1999, pp. 674-685
Citations number
14
Categorie Soggetti
Envirnomentale Medicine & Public Health
Journal title
TROPICAL MEDICINE & INTERNATIONAL HEALTH
ISSN journal
13602276 → ACNP
Volume
4
Issue
10
Year of publication
1999
Pages
674 - 685
Database
ISI
SICI code
1360-2276(199910)4:10<674:FOSMNC>2.0.ZU;2-V
Abstract
In the province of Kracheh, in Northern Cambodia, a baseline epidemiologica l survey on Schistosoma mekongi was conducted along the Mekong River betwee n 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 peop le were examined. An overall prevalence of infection of 49.3% was detected by a single stool examination with the Kato-Katz technique. The overall int ensity of infection was 118.2 eggs per gram of stool (epg). There was no di fference between the population of the east and west shore of the Mekong fo r prevalence (P = 0.3) or intensity (P = 0.9) of infection. Severe morbidit y 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 ascit es in 0.1%. Significantly more hepatomegaly (P = 0.001), splenomegaly (P = 0.001) and patients with diverted circulation (P = 0.001) were present on t he 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 popul ation of the West and East of the Mekong, respectively. The intensity of in fection 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 w est and 82.8% on the east bank. In the 20 schools 2391 children aged 6-16 y ears 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) a nd 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 mu cus (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) we re significantly more frequent in schools of the east side of the Mekong. B oys suffered more frequently from splenomegaly (P = 0.05), ascites (P = 0.0 5) and bloody stools (P = 0.004) than girls. No difference in sex was found for the prevalence and intensity of infection and prevalence of hepatomega ly On the school level prevalence and intensity of infection were highly as sociated (r = 0.93, P = 0.0001). The intensity of infection was significant ly associated only with the prevalence of hepatomegaly (r = 0.44, P = 0.05) and blood in stool (r = 0.40, P = 0.02). This comprehensive epidemiologica l study documents for the first time the public health importance of schist osomiasis mekongi in the Province of Kracheh, Northern Cambodia and points at key epidemiological features of this schistosome species, in particular the high level of morbidity associated with infection.