Journal Article

Evidence of non-Plasmodium falciparum malaria infection in Kédougou, Sénégal

Ndiop, Medoune, Volkman, Sarah K., Ndiaye, Daouda, Ndiaye, Yaye Die, Dieye, Baba, Gomis, Jules F., Fall, Fatou B., Badiane, Aida S., Durfee, Katelyn, Deme, Awa Bineta, Thwing, Julie I., Ba, Mady, Wirth, Dyann F., Daniels, Rachel F.

2017

Overview

Background Expanded malaria control efforts in Sénégal have resulted in increased use of rapid diagnostic tests (RDT) to identify the primary disease-causing Plasmodium species, Plasmodium falciparum . However, the type of RDT utilized in Sénégal does not detect other malaria-causing species such as Plasmodium ovale spp., Plasmodium malariae , or Plasmodium vivax . Consequently, there is a lack of information about the frequency and types of malaria infections occurring in Sénégal. This study set out to better determine whether species other than P. falciparum were evident among patients evaluated for possible malaria infection in Kédougou, Sénégal. Methods Real-time polymerase chain reaction speciation assays for P. vivax, P. ovale spp., and P. malariae were developed and validated by sequencing and DNA extracted from 475 Plasmodium falciparum -specific HRP2-based RDT collected between 2013 and 2014 from a facility-based sample of symptomatic patients from two health clinics in Kédougou, a hyper-endemic region in southeastern Sénégal, were analysed. Results Plasmodium malariae (n = 3) and P. ovale wallikeri (n = 2) were observed as co-infections with P. falciparum among patients with positive RDT results (n = 187), including one patient positive for all three species. Among 288 negative RDT samples, samples positive for P. falciparum (n = 24), P. ovale curtisi (n = 3), P. ovale wallikeri (n = 1), and P. malariae (n = 3) were identified, corresponding to a non- falciparum positivity rate of 2.5%. Conclusions These findings emphasize the limitations of the RDT used for malaria diagnosis and demonstrate that non- P. falciparum malaria infections occur in Sénégal. Current RDT used for routine clinical diagnosis do not necessarily provide an accurate reflection of malaria transmission in Kédougou, Sénégal, and more sensitive and specific methods are required for diagnosis and patient care, as well as surveillance and elimination activities. These findings have implications for other malaria endemic settings where species besides P. falciparum may be transmitted and overlooked by control or elimination activities.

• Publisher: BioMed Central,Springer Nature B.V
• Subject: Adolescent / Adult / Aged / Aged, 80 and over / Biomedical and Life Sciences / Biomedicine / Child / Child, Preschool / Deoxyribonucleic acid / Diagnosis / Diagnostic Tests, Routine - methods / Disease transmission / DNA / DNA sequencing / Endemic species / Entomology / Erythrocytes / Female / Genetic testing / Human diseases / Humans / Infant / Infections / Infectious Diseases / Malaria / Malaria - epidemiology / Male / Methods / Microbiology / Middle Aged / Nucleotide sequence / Parasites / Parasitology / PCR / Plasmids / Plasmodium falciparum / Plasmodium malariae / Plasmodium malariae - classification / Plasmodium malariae - genetics / Plasmodium malariae - isolation & purification / Plasmodium ovale - classification / Plasmodium ovale - genetics / Plasmodium ovale - isolation & purification / Plasmodium vivax - classification / Plasmodium vivax - genetics / Plasmodium vivax - isolation & purification / Polymerase chain reaction / Prevalence / Public Health / Real-Time Polymerase Chain Reaction / Senegal - epidemiology / Sensitivity and Specificity / Speciation / Trends / Tropical Medicine / Vector-borne diseases / Young Adult