Probing the composition of Plasmodium species contained in malaria infections in the Eastern region of Ghana

Linda Eva Amoah,Colins Ahorlu,Daniel Arhinful,Edwin Afari,Dickson Donu,Kwadwo Ansah Koram,Keziah Malm,Benjamin Abuaku

doi:10.1186/s12889-019-7989-1

Linda Eva Amoah, Colins Ahorlu + Show 6 more

Open Access

https://doi.org/10.1186/s12889-019-7989-1

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Abstract

BackgroundAsymptomatic falciparum and non-falciparum malaria infections are major challenges to malaria control interventions, as they remain a source of continual infection in the community. This becomes even more important as the debate moves towards elimination and eradication. This study sought to quantify the burden of Plasmodium malaria infection in seven communities in the Eastern Region of Ghana.MethodsThe cross-sectional study recruited 729 participants aged 85 years old and below from 7 closely linked communities. Finger pricked blood was used to prepare thick and thin blood smears as well as spot filter paper and an histidine rich protein 2 (HRP2) rapid diagnostic test kit (RDT). Genomic DNA was extracted from the filter paper dry blood spot (DBS) and used in PCR to amplify the Plasmodium 18S rRNA gene using species specific PCR.Results96.6% of the participants were identified as afebrile, with axillary temperatures below 37.5 °C. PCR identified 66% of the participants to harbor malaria parasites, with 9 P. malariae and 7 P. ovale mono-infections accounting for 2.2% and P. falciparum combined with either 36 P. malariae or 25 P. ovale infections, accounting for 13.3%. Parasite prevalence by microscopy (32%) was similar to the RDT positivity rate (33%). False positive RDT results ranged from 64.6% in children aged between 5 and 9 years to 10% in adults aged 20 years and above. No significant differences were observed in falciparum and non-falciparum parasite carriage at the community level, however young adults aged between 15 and 19 years had the highest prevalence (34.8% (16/46)) of P. falciparum and P. malariae parasite carriage whilst children aged between 5 and 9 years had the highest level (11.4% (14/123)) of P. ovale carriage.ConclusionThe high rate of misidentification of non-falciparum parasites and the total absence of detection of P. ovale by microscopy suggests that more sensitive malaria diagnostic tools including molecular assays are required to accurately determine the prevalence of carriers of non-falciparum parasites and low density P. falciparum infections, especially during national surveillance exercises. Additionally, malaria control interventions targeting the non-falciparum species P. malariae and P. ovale parasites are needed.

Highlights

Asymptomatic falciparum and non-falciparum malaria infections are major challenges to malaria control interventions, as they remain a source of continual infection in the community
Malaria, a parasitic disease caused in humans by five different species of the Plasmodium genus namely P. falciparum, P. malariae, P. ovale, P. vivax and P. knowlesi, remains a devastating public health problem in the tropical and subtropical regions worldwide [1]
In sub-Saharan African, the majority of malaria cases are caused by P. falciparum [1] with a minor but underestimated prevalence of other Plasmodium species [5]

Summary

Introduction

Asymptomatic falciparum and non-falciparum malaria infections are major challenges to malaria control interventions, as they remain a source of continual infection in the community. This becomes even more important as the debate moves towards elimination and eradication. A parasitic disease caused in humans by five different species of the Plasmodium genus namely P. falciparum, P. malariae, P. ovale, P. vivax and P. knowlesi, remains a devastating public health problem in the tropical and subtropical regions worldwide [1]. In sub-Saharan African, the majority of malaria cases are caused by P. falciparum [1] with a minor but underestimated prevalence of other Plasmodium species [5]. Despite the widespread absence of the Duffy antigen receptor for chemokines in people from sub Saharan Africa a few recent reports of have identified P. vivax infections in some sub Saharan African countries including Mali and Nigeria [14,15,16]

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