H. Birrie et al., INTESTINAL HELMINTHIC INFECTIONS IN THE SOUTHERN RIFT-VALLEY OF ETHIOPIA WITH SPECIAL REFERENCE TO SCHISTOSOMIASIS, East African medical journal, 71(7), 1994, pp. 447-452
Nineteen communities located in the southern part of the Ethiopian Rif
t Valley were surveyed for S, mansoni infection and other helminth par
asites of man, S, mansoni infected individuals were recorded in 11 com
munities and human prevalence reached more than 10% in 4 of them, The
snail intermediate hosts were Biomphalaria pfeifferi in the lower Omo
River basin and B, sudanica in the Rift Valley lakes, Other parasites
encountered included A, lumbricoides (11.2%), T, trichiura (10.3%), ho
okworms (25.3%), Taenia sp, (8.1%), Strongyloides sp, (2.9%), H, nana
(0.8%), Trichostrongylus sp (0.3%) F, hepatica (0.1%) and E, vermicula
ris (0.1%), In some communities the prevalence of hookworms, A, lumbri
coides and T, trichiura reached 70%, 66.6% and 60%, respectively, a st
rong association (r = 0.9) was observed between altitude and parasite
prevalence and burden, In nine communities located below 1200 metres,
infected individuals harboured nearly two or less the number of parasi
te species while in 10 communities located at altitude above 1200 metr
es, multiple infection with three or more parasites reached as high as
53.2%, Similarly, the average parasite species per infected person ra
nged from 0 to 1.4 in the nine communities located at lower altitudes
and from 1% to 2.6% in the 10 communities located at higher altitudes,
By ages, both prevalence and multiparasitism are significantly in fav
our of those below 20 years of age (P<0.005) although hookworms are pr
evalent in a wider age range, The widespread occurrence of intestinal
schistosomiasis in the southern Rift Valley and the epidemiological pa
ttern of other intestinal helminth parasites of man In this section of
the Valley are discussed.