The epidemiology of schistosomiasis in Egypt: Menofia Governorate

Health questionnaires and parasitologic examinations of urine and stool wer e performed upon a stratified random sample of 10,899 individuals from 1,53 7 households in 27 rural communities in Menofia Governorate in Egypt in 199 2 to investigate the prevalence of, risk factors for, and changing pattern of infection with Schistosoma sp, in the governorate. A subset, every fifth household, or 1,480 subjects, had physical and ultrasound examinations to investigate prevalence of and risk factors for morbidity. The prevalence of S. mansoni ranged from 0.3% to 72.9% and averaged 28.5%. The geometric mea n egg count was 81.3 eggs/gram of stool. Age-stratified prevalence and inte nsity of infection was 30-40% and 60-80 eggs/gram of stool from the age of 10-onward; males had higher infection rates and ova counts than females in all age groups > 10 years old. Schistosoma haematobium was rare, being cons equential in only 1 community. Risk factors for S, mansoni infection were m ale gender; age > 10 years; living in smaller communities; exposures to can al water; history of or treatment for schistosomiasis or blood in the stool ; detection of splenomegaly by either physical or ultrasound; and ultrasoun d-detected periportal fibrosis (PPF). The more severe grades of PPF were ra rely (21 of 1,450 examinations) detected. Risk factors for morbidity, i.e., ultrasound-detected PPF, were similar to those for infection. Schistosoma mansoni has almost totally replaced S. haematobium in Menofia. The prevalen ce of S. mansoni In rural communities remains high and average intensities of infection are moderate. The association of morbidity with schistosomal i nfection was variable and is obviously markedly influenced by both the freq uent use of antischistosomal chemotherapy in communities in Menofia and by the prevalence of complications from chronic viral hepatitis in the populat ion: hepatomegaly did not correlate with infection; PPF and splenomegaly, h owever, were related to S. mansoni infection in both individuals and commun ities.