Malaria Parasite Species Composition of Plasmodium Infections Among Asymptomatic and Symptomatic School-Age Children in Rural and Urban Areas of Kinshasa, Democratic Republic of Congo

Nundu, Sabin S.; Culleton, Richard; Simpson, Shirley V.; Arima, Hiroaki; Muyembe, Jean-Jacques; Mita, Toshihiro; Ahuka, Steve; Yamamoto, Taro

doi:10.21203/rs.3.rs-389568/v1

Cited by 3 publications

(11 citation statements)

References 61 publications

(77 reference statements)

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“…According to the WHO World Malaria Report 2021, DRC and Uganda are, after Nigeria, the two countries with the highest incidence of diagnosed malaria cases globally, 1 along with a high parasite prevalence. 19,20 In our study, the malaria parasite prevalence found in migrants with Uganda as the country of last residence was similar to the 10-35% prevalence reported from a refugee camp in Uganda. 21 This demonstrates that migrant populations are at risk for malaria infections and may still carry the infection after arrival to a non-endemic setting.…”

Section: Discussionsupporting

confidence: 86%

Malaria parasite prevalence in asymptomatic migrants residing in Sweden

Wångdahl

Bogale

Eliasson

et al. 2022

Preprint

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Background Asymptomatic infections with malaria parasites are common in populations in endemic areas. These infections may persist in migrants after arrival in a non-endemic area. Screening to find and clear these infections is generally not implemented in non-endemic countries, despite a potential negative health impact. We performed a study to evaluate the Plasmodium parasite prevalence in migrants living in Sweden. Methods Adults and children born in Sub-Saharan Africa (SSA) were invited in the study between April 2019 and June 2022 at 10 different sites. Rapid diagnostic tests (RDT) and real-time PCR were used to detect malaria parasites. Prevalence and test sensitivity were calculated with 95% confidence intervals (CI). Univariate and multivariable logistic regression were used to evaluate associations with PCR positivity. Findings In total, 789 individuals were screened for Plasmodium spp., of which 71 (9.0%) were detected by PCR and 18 (2.3%) were also RDT positive. A high prevalence was detected in migrants with Uganda as the country of last residence, 53/187 (28.3%), particularly in children, 29/81 (35.8%). Among the PCR positive, 47/71 (66.2%) belonged to families with at least one other member testing positive (OR 43.4 (95% CI 19.0-98.9), and the time lived in Sweden ranged between 6-386 days. Interpretation A high malaria parasite prevalence was found in migrants from SSA, particularly in children. Awareness of asymptomatic malaria infection is needed and screening for malaria in migrants arriving from high endemic countries should be considered. Funding Swedish Research Council, Stockholm County Council and Centre for Clinical Research, Vastmanland, Sweden.

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Section: Discussionsupporting

confidence: 86%

Malaria parasite prevalence in asymptomatic migrants residing in Sweden

Wångdahl

Bogale

Eliasson

et al. 2022

Preprint

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“…Samples for this study were collected as part of a cross-sectional study carried out from October to November 2019 in Kinshasa province, DRC [49]. The original study was conducted at primary schools and health facilities in the rural area of Mont-Ngafula 2 Health Zone (HZ) and the urban area of Selembao HZ.…”

Section: Study Site and Source Of Samplesmentioning

confidence: 99%

“…A total of 438 P. falciparum-positive genomic DNA samples were analysed in this study. The details of the study site and sampling procedures have been previously described [49].…”

Section: Study Site and Source Of Samplesmentioning

confidence: 99%

“…School-age children are often neglected in malaria control interventions, and thus constitute a reservoir of infections and signi cant contribution to malaria transmission [44][45][46][47][48][49]. In high transmission settings, about 70% of school-age children (5 to 14 years old) have a higher prevalence of malaria compared to children under ve [46].…”

Section: Introductionmentioning

confidence: 99%

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The diversity of Plasmodium falciparum isolates from asymptomatic and symptomatic school-age children in Kinshasa province, Democratic Republic of Congo

Simpson

Nundu

Arima

et al. 2022

Preprint

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Background. Understanding Plasmodium falciparum population diversity and transmission dynamics provides information on the intensity of malaria transmission, which is needed for assessing malaria control interventions. We investigated P. falciparum allelic diversity and multiplicity of infection (MOI) in asymptomatic and symptomatic school-age children in Kinshasa province, Democratic Republic of Congo (DRC). Methods. A total of 438 DNA samples (248 asymptomatic and 190 symptomatic) were characterized by nested PCR and genotyping the polymorphic regions of pfmsp1 block 2 and pfmsp2 block 3. Results. Nine allele types were observed in pfmsp1 block2. The K1-type allele was predominant with 78% (229/293) prevalence, followed by the MAD20-type allele (52%, 152/293) and RO33-type allele (44%, 129/293). Twelve alleles were detected in pfmsp2; and the 3D7-type allele was the most frequent with 84% (256/304) prevalence, followed by the FC27-type allele (66%, 201/304). Polyclonal infections were detected in 63% (95% CI: 56, 69) of the samples, and the MOI was 2.0 (95% CI: 1.9, 2.1) in P. falciparum single species infections. MOIs significantly increased in Plasmodium falciparum isolates from symptomatic parasite carriers than asymptomatic ones (2.24 versus 1.69, Adjusted b: 0.36, (95% CI: 0.01, 0.72), p = 0.046) and parasitemia >10,000 parasites/µL compared to parasitemia <5,000 parasites/µL (2.68 versus 1.63, Adjusted b: 0.89, (95% CI: 0.46, 1.25), p < 0.001). Conclusion. Our survey showed low allelic diversity and MOI of P. falciparum, which reflects a moderate intensity of malaria transmission in the study areas. MOIs were more likely to be common in symptomatic infections and increased with the parasitemia level. Further studies in different transmission zones are needed to understand the epidemiology and parasite complexity in the DRC.

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“…7 Prevalence surveys that have been conducted in urban areas consistently identify a small percentage of infected individuals, and entomological surveys have found Anopheles mosquitoes in multiple African cities. 8,9 Given the fast pace of urbanization, particularly in sub-Saharan Africa, and the changing climates, there is a growing concern of the impact on malaria transmission in urban environments. 10,11 For countries to achieve malaria elimination, the question around the extent of malaria transmission in urban settings must be addressed.…”

Section: Introductionmentioning

confidence: 99%

Optimizing Routine Malaria Surveillance Data in Urban Environments: A Case Study in Maputo City, Mozambique

Stresman

Stratil

Gomane³

et al. 2023

The American Journal of Tropical Medicine and Hygiene

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In urban settings in malaria-endemic countries, malaria incidence is not well characterized and assumed to be typically very low and consisting largely of imported infections. In such contexts, surveillance systems should adapt to ensure that data are of sufficient spatial and temporal resolution to inform appropriate programmatic interventions. The aim of this research was to 1) assess spatial and temporal trends in reported malaria cases in Maputo City, Mozambique, using an expanded case notification form and 2) to determine how malaria surveillance can be optimized to characterize the local epidemiological context, which can then be used to inform targeted entomological investigations and guide implementation of localized malaria responses. This study took place in all six health facilities of KaMavota District in Maputo City, Mozambique. A questionnaire was administered to all confirmed cases from November 2019 to August 2021. Households of cases were retrospectively geolocated using local landmarks as reference. Overall, 2,380 malaria cases were reported, with the majority being uncomplicated (97.7%) and a median age of 21 years; 70.8% of cases had reported traveling outside the city in the past month with nine reporting traveling internationally. Maps of the 1,314 malaria cases that were geolocated showed distinct spatial patterns. The expanded case notification form enables a more granular overview of the malaria epidemiology in Maputo City; the geolocation data clearly show the areas where endemic transmission is likely, thus informing where resources should be prioritized. As urbanization is rapidly increasing in malaria endemic areas, identifying systems and key variables to collect ensures an operational way to characterize urban malaria through optimization of routine data to inform decision-making.

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Malaria Parasite Species Composition of Plasmodium Infections Among Asymptomatic and Symptomatic School-Age Children in Rural and Urban Areas of Kinshasa, Democratic Republic of Congo

Cited by 3 publications

References 61 publications

Malaria parasite prevalence in asymptomatic migrants residing in Sweden

Malaria parasite prevalence in asymptomatic migrants residing in Sweden

The diversity of Plasmodium falciparum isolates from asymptomatic and symptomatic school-age children in Kinshasa province, Democratic Republic of Congo

Optimizing Routine Malaria Surveillance Data in Urban Environments: A Case Study in Maputo City, Mozambique

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