Urban malaria in Nazareth, Ethiopia: parasitological studies.

Cross-sectional surveys for parasite infection, and factors that possibly influence human malaria transmission were carried out to characterize the epidemiology of urban malaria in Nazareth. Thick and thin blood films for parasite diagnosis were collected from individuals residing in 6 representative kebeles in the town. A questionnaire was used to obtain socioeconomic information. An overall parasite rate of 2.8%, P. falciparum (1.6%) and P. vivax (1.2%)- was observed among the 3890 individuals examined during the 4 surveys. Significant intra-urban differences (X2 = 27.31; P < 0.0001), in parasite rates, were observed with a much higher prevalence in the peripheral kebeles. A marked seasonal variation in parasite rates was evident during the sampling period and the peak occurred in Sept./Oct. There was no apparent decrease in parasite rate with increase in age, suggesting a delayed acquired immunity, typical of hypoendemic settings. The study has indicated that in Nazareth the prevalence of malaria is seasonally variable and relatively low, showing that it is unstable. Hence, if appropriate control measures are not instituted, malaria situation in -Nazareth is subject to epidemics.