Sero-identification of the aetiologies of human malaria exposure (Plasmodium spp.) in the Limu Kossa District of Jimma Zone, South western Ethiopia

Abstract

Background Malaria remains a very important public health problem in Ethiopia. Currently, only Plasmodium falciparum and Plasmodium vivax are considered in the malaria diagnostic and treatment policies. However, the existence and prevalence of Plasmodium ovale spp. and Plasmodium malariae in Ethiopia have not been extensively investigated. The objective of this study was to use a multiplex IgG antibody detection assay to evaluate evidence for exposure to any of these four human malaria parasites among asymptomatic individuals. Methods Dried blood spots (DBS) were collected from 180 healthy study participants during a 2016 onchocerciasis survey in the Jimma Zone, southwest Ethiopia. IgG antibody reactivity was detected using a multiplex bead assay for seven Plasmodium antigens: P. falciparum circumsporozoite protein (CSP), P. falciparum apical membrane antigen-1 (AMA1), P. falciparum liver stage antigen-1 (LSA1), and homologs of the merozoite surface protein-1 (MSP1)-19kD antigens that are specific for P. falciparum , P. vivax , P. ovale spp. and P. malariae. Results One hundred six participants (59%) were IgG seropositive for at least one of the Plasmodium antigens tested. The most frequent responses were against P. falciparum AMA1 (59, 33%) and P. vivax (55, 28%). However, IgG antibodies against P. ovale spp. and P. malariae were detected in 19 (11%) and 13 (7%) of the participants, respectively, providing serological evidence that P. malariae and P. ovale spp., which are rarely reported, may also be endemic in Jimma. Conclusion The findings highlight the informative value of multiplex serology and the need to confirm whether P. malariae and P. ovale spp. are aetiologies of malaria in Ethiopia, which is critical for proper diagnosis and treatment.

Malaria serology data from the Guiana shield: first insight in IgG antibody responses to Plasmodium falciparum, Plasmodium vivax and Plasmodium malariae antigens in Suriname

“…However, even lower cut-off values have been demonstrated in a study setting in Haiti among 247 US citizens [ 14 ]. The observed lower cut-off value for MSP-1 19 for P. falciparum compared to MSP-1 19 for the other two Plasmodium species was in line with recent results [ 20 ].…”

“…However, even lower cut-off values have been demonstrated in a study setting in Haiti among 247 US citizens [14]. The observed lower cut-off value for MSP-1 19 for P. falciparum compared to MSP-1 19 for the other two Plasmodium species was in line with recent results [20]. Prior to 2006, Suriname had a very high malaria burden and was even considered as the country in the Americas with the highest concentration of falciparum malaria [21], which was reflected in the higher P. falciparum seroprevalence in villagers from Stoelmanseiland compared to the mobile migrants from the Benzdorp region.…”

“…The use of a reference population of Surinamese with no malaria history, instead of the general reference population consisting of US citizens with no travel history to malariaendemic countries, enabled the generation of a true representation of the actual 'negative' serodistribution in this setting. The generated cut-off values in this study were lower than cut-off values for the commonly used reference population consisting of US citizens [20], probably due to the low background of the immunoassay and differences related to the coupling of the beads. However, even lower cut-off values have been demonstrated in a study setting in Haiti among 247 US citizens [14].…”

“…Data on malaria history revealed that the majority of participants (75.6%) reported one or more past malaria episodes, of which only 21.5% could recollect the responsible Plasmodium species. Furthermore, 70.5% of the participants with a malaria history reported [17][18][19]; AMA-1: 19 [16][17][18][19][20][21][22]; GLURP: 13 [12][13][14][15]; CSP: 33 [32,33] and LSA-1: 14 [14,15]. The horizontal line represents the calculated cut-off of the respective antibody.…”

Antibody Profile Comparison against MSP1 Antigens of Multiple Plasmodium Species in Human Serum Samples from Two Different Brazilian Populations Using a Multiplex Serological Assay

“…Studies for the detection of antibodies against Plasmodium MSP1 proteins are increasingly used to map geographical distributions, seroprevalence and transmission intensities of malaria infection [22][23][24]. The C-terminal portion of the merozoite surface protein 1 (MSP1 19 ) is a promising candidate for the malaria vaccine, as it is highly immunogenic [25,26], therefore being extensively analyzed as an immunological target in many studies [23,[25][26][27][28]. On the other hand, many studies also use the N-terminal portion of MSP1, which elicits a strong IgG response in P. vivax and P. falciparum infections [29][30][31][32].…”