Malaria Transmission and Asymptomatic Malaria during Rainy Season among Nomads, North-eastern Nigeria

Aim: To determine the point prevalence of malaria infection and asymptomatic malaria during rainy season among some nomads of North Eastern Nigeria.

Study Design: A cross sectional observational study.

Place and Duration of Study: The study was conducted across 11 randomly selected nomads’ camps around the Rivers Gongola and Benue basins spread over 3 Local Government Areas of Southern Adamawa State of North Eastern Nigeria. Data was collected during rainy season between July and September, 2016.

Methodology: Fifty-five randomly selected households (5 from each camp) were covered in the survey. One hundred and ninety two (192) consenting participants aged between 1 and 79 years (inclusive) were involved in the survey. Structured questionnaires were administered (care givers consented and responded on behalf of children) and blood samples collected. Blood samples were examined for malaria parasite using a microscopes and results of both survey and microscopy analysed.

Results: Overall malaria parasite prevalence was 87.5% and mean parasite density was 36,168 parasites per μl of blood. Thirty five (18.2%) of participant were of low parasite density, 35.5% were of moderate parasite density while 32.8% were of high parasite density. More than half (53%) of the malaria positive participants did not experience febrile symptoms within one month prior to the survey and were therefore asymptomatic. Tendency of manifestation of symptoms significantly increased with parasite density and decreased with age. The use of preventive measures against mosquito bite was 7.7% and only 16.1% of participants used antimalarial medicines or sought medical attention during their most recent fever episode.

Conclusion: The high prevalence of asymptomatic carriers with high parasite densities and abysmally low usage of preventive and curative measures among the study population represents an ideal condition for effective malaria transmission which is unlikely to abate unless control measures are intensified.