Malaria in children of Tshimbulu (Western Kasai, Democratic Republic of the Congo): epidemiological data and accuracy of diagnostic assays applied in a limited resource setting

Abstract

BackgroundThe literature data on malaria in Western Kasai, DRC, are limited and inadequate. A recent molecular survey there has detected Plasmodium ovale and Plasmodium malariae as mixed infections with Plasmodium falciparum. In Tshimbulu, Western Kasai, during a humanitarian initiative designed to provide children with free preventive screening and to reduce the local high malaria death rate, accurate species identification was performed, in order to collect unambiguous epidemiological data and to evaluate the reliability of locally applied diagnostics.MethodsFinger pricks provided fresh blood for microscopic analysis (MA), for rapid diagnostic test (RDT) and for molecular diagnostics (MD). MA and RDT were first performed by the local team and then a re-interpretation of the results (on the same slides and on RDT’s taken pictures) was conducted in Italy, where MD were performed.ResultsThe analysis was conducted on 306 children; RDT found 80.9 % as P. falciparum-positive (37.4 % as two-band positive, P. falciparum single infection). MA identified a further four children as positive to P. falciparum and six co-infections with P. ovale. The second RDT evaluation confirmed a similar infection rate (78.2 %) but interpreted as two-band positive a significantly higher share of tests (56.8 %). MA confirmed 80.0 % of the children as malaria positive and, in addition to P. falciparum, identified P. malariae (13.8 %), P. vivax (3.4 %) and P. ovale (2.4 %), and detected Babesia microti in 19 smears. MD confirmed all of the species found (Babesia microti included), classified as mono-infection with P. falciparum a rate of spots comparable to MA revision, and identified all P. ovale as Plasmodium ovale wallikeri. The RDT used locally proved 93.1 % sensitive and 92.1 % specific for P. falciparum.ConclusionsThe malaria prevalence among the children and the presence of four Plasmodium species, highlighted in this study, identified a sanitary issue which proved to be more alarming than expected, as it was worsened by the unpredictable presence of P. vivax and Babesia microti (never before reported in DRC). Each diagnostic tool showed its point of weakness. Therefore, the most correct approach is by the combined use of different, locally available, diagnostic tools.

Low prevalence of Plasmodium malariae and Plasmodium ovale mono-infections among children in the Democratic Republic of the Congo: a population-based, cross-sectional study

“…Using a sub-set of 462 samples from the large, cross-sectional DHS, the prevalence of P. malariae and P. ovale among children in the DRC was found to be 12.9 and 8.3 %, respectively, with widespread geographical distributions seen in both species. A recent study of children in Western Kasai, DRC found a similar prevalence of P. malariae (13.8 %) but a lower prevalence of P. ovale (2.4 %) [ 14 ], and another study of asymptomatic individuals in six provinces of the DRC found a much lower prevalence of P. malariae (1.0 %) [ 15 ]. In 2007 prevalence were 4.9 % for P. malariae and 0.6 % for P. ovale [ 16 ].…”

“…In this study, the mono-infection prevalence were only 1.0 and 0.6 %, respectively. In Western Kasai, there were no P. malariae or P. ovale mono-infections reported [ 14 ].…”

Babesia microti Confers Macrophage-Based Cross-Protective Immunity Against Murine Malaria

“…(Na et al, 2014), while an imported babesiosis case involving co-infection with P. falciparum was previously described in the country (Ahn, 2010). Finally, in the Democratic Republic of Congo, coinfection with B. microti and P. falciparum has been diagnosed in minors with a prevalence of 1-6% (Gabrielli et al, 2016). Besides humans, cases of natural co-infection have also been described in closely related primate species; a macaque infected with a B. microti-like parasite exhibited suppressed P. cynomolgi infection (Wel et al, 2008), while co-infection in lemurs resulted in suppression of malaria infection and pathogenesis (Springer et al, 2015).…”

Prevalence of Congenital Malaria in Kisangani, A Stable Malaria Transmission Area in Democratic Republic of the Congo

“…These two countries alone, added to India, account for 40% of malaria cases [6]. In northeast DRC where Tshopo province is located, malaria is the cause of consultation in 37% of all pathologies and the cause of death at 30% of cases [4,5]. The equatorial facies which dominates this province in general and the city of Kisangani in particular and the presence of Plasmodium falciparum which ensures intense and permanent transmission as well as the insanitary condition of the environment would be the cause.…”