Continuing Intense Malaria Transmission in Northern Uganda

Abstract

Abstract. Recent reports of reductions in malaria transmission in several African countries have resulted in optimism that malaria can be eliminated in parts of Africa where it is currently endemic. It is not known whether these trends are global or whether they are also present in areas where political instability has hindered effective malaria control. We determined malaria parasite carriage and age-dependent antibody responses to Plasmodium falciparum antigens in cross-sectional surveys in Apac, northern Uganda that was affected by political unrest. Under-five parasite prevalence was 55.8% (115/206) by microscopy and 71.9% (41/57) by polymerase chain reaction. Plasmodium ovale alone, or as a co-infection, was detected in 8.6% (12/139) and Plasmodium malariae in 4.3% (6/139) of the infections. Age seroprevalence curves gave no indication of recent changes in malaria transmission intensity. Malaria control remains a tremendous challenge in areas that have not benefited from large-scale interventions, illustrated here by the district of Apac.

Marked Age-Dependent Prevalence of Symptomatic and Patent Infections and Complexity of Distribution of Human Plasmodium Species in Central Vietnam

“…These findings confirm previous reports from other countries in Southeast Asia and Africa, where use of molecular techniques showed a high complexity of infections, i.e., high proportions of mixed infections and high occurrence of P. malariae and P. ovale compared with that detected by standard microscopy 7,8,16–18…”

The Effect of Indoor Residual Spraying on Malaria and Anemia in a High-Transmission Area of Northern Uganda

“…Although true baseline data are lacking, a 2009 study in Apac indicated a 55.8% parasite prevalence rate in children 5 years. 16 The sampling methods are different between this survey and our survey (testing of community members at health centers versus testing during household interviews), but this prevalence is substantially higher than the 37.0% parasite rate that we found in our survey nearly 2 years later after two additional rounds of IRS had been conducted.…”

“…Parasite prevalence was measured to be 79.8% among children 1-9 years of age in 1999 14 and 55.8% among children under 5 years old in 2009. 16 The US President's Malaria Initiative (PMI) began supporting IRS in northern Uganda in 2007, starting with four highly endemic districts (Kitgum, Pader, Gulu, and Amuru) and further expanding to two more districts in 2008 (Apac and Oyam). The current program continues to cover those 6 districts (now 10 districts after administrative reorganization in 2010) and has shifted from use of DDT and pyrethroids to carbamates as a result of resistance data from entomological monitoring.…”

Seroprevalence of Antibodies against Plasmodium falciparum Sporozoite Antigens as Predictive Disease Transmission Markers in an Area of Ghana with Seasonal Malaria Transmission

“…Anti-sporozoite antibody levels were high during the rainy season and decreased significantly to low levels in the dry season (Table 3). Anti-AMA1 antibody seroprevalence was not different between seasons, confirming the persistence of these antibodies and the reduced likelihood of anti-AMA1 antibodies fluctuating with short term changes in transmission intensity [20,37]. …”