High-Complexity Plasmodium falciparum Infections, North Central Nigeria, 2015–2018

The mass migration that occurred during 2009–2013 and after the insurgency in northeastern Nigeria could have increased malaria incidence and Plasmodium falciparum genetic diversity in North Central Nigeria. To determine P. falciparum sequence diversity in this region, we screened 282 samples collected in regional clinics during 2015–2018 for Plasmodium spp. and, with positive samples, determined P. falciparum infection complexity and allele diversity using PCR. Of 34 P. falciparum–positive samples, 39 msp1, 31 msp2, and 13 glurp alleles were detected, and 88% of infections were polyclonal. We identified trimorphic and dimorphic allele combinations in a high percentage of samples, indicative of a high infection complexity in the study population. High genetic diversity is a catalyst for the evolution of drug-resistant alleles. Improved measures (e.g., better drug quality, diagnostics) are needed to control P. falciparum transmission and reduce the potential for the emergence of drug resistance in Nigeria.