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  • 1
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    Molecular characterization and genotype distribution of thioester-containing protein 1 gene in Anopheles gambiae mosquitoes in western Kenya
    Springer Science and Business Media LLC ; 2022
    In:  Malaria Journal Vol. 21, No. 1 ( 2022-08-10)
    Details
    In: Malaria Journal, Springer Science and Business Media LLC, Vol. 21, No. 1 ( 2022-08-10)
    Abstract: Evolutionary pressures lead to the selection of efficient malaria vectors either resistant or susceptible to Plasmodium parasites. These forces may favour the introduction of species genotypes that adapt to new breeding habitats, potentially having an impact on malaria transmission. Thioester-containing protein 1 (TEP1) of Anopheles gambiae complex plays an important role in innate immune defenses against parasites. This study aims to characterize the distribution pattern of TEP1 polymorphisms among populations of An. gambiae sensu lato ( s.l .) in western Kenya. Methods Anopheles gambiae adult and larvae were collected using pyrethrum spray catches (PSC) and plastic dippers respectively from Homa Bay, Kakamega, Bungoma, and Kisumu counties between 2017 and 2020. Collected adults and larvae reared to the adult stage were morphologically identified and then identified to sibling species by PCR. TEP1 alleles were determined in 627 anopheles mosquitoes using restriction fragment length polymorphisms-polymerase chain reaction (RFLP-PCR) and to validate the TEP1 genotyping results, a representative sample of the alleles was sequenced. Results Two TEP1 alleles (TEP1*S1 and TEP1*R2) and three corresponding genotypes (*S1/S1, *R2/S1, and *R2/R2) were identified. TEP1*S1 and TEP1*R2 with their corresponding genotypes, homozygous *S1/S1 and heterozygous *R2/S1 were widely distributed across all sites with allele frequencies of approximately 80% and 20%, respectively both in Anopheles gambiae and Anopheles arabiensis. There was no significant difference detected among the populations and between the two mosquito species in TEP1 allele frequency and genotype frequency. The overall low levels in population structure ( F ST  = 0.019) across all sites corresponded to an effective migration index (Nm = 12.571) and low Nei’s genetic distance values ( 〈  0.500) among the subpopulation. The comparative fixation index values revealed minimal genetic differentiation between species and high levels of gene flow among populations. Conclusion Genotyping TEP1 has identified two common TEP1 alleles (TEP1*S1 and TEP1*R2) and three corresponding genotypes (*S1/S1, *R2/S1, and *R2/R2) in An. gambiae s.l. The TEP1 allele genetic diversity and population structure are low in western Kenya.
    Type of Medium: Online Resource
    ISSN: 1475-2875
    URL: Article
    DOI: 10.1186/s12936-022-04256-w
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
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  • 2
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    Perennial transmission of malaria in the low altitude areas of Baringo County, Kenya
    Springer Science and Business Media LLC ; 2017
    In:  Malaria Journal Vol. 16, No. 1 ( 2017-12)
    Details
    In: Malaria Journal, Springer Science and Business Media LLC, Vol. 16, No. 1 ( 2017-12)
    Type of Medium: Online Resource
    ISSN: 1475-2875
    URL: Article
    DOI: 10.1186/s12936-017-1904-y
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2017
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  • 3
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    Habitat Diversity, Stability, and Productivity of Malaria Vectors in Irrigated and Nonirrigated Ecosystems in Western Kenya
    Oxford University Press (OUP) ; 2023
    In:  Journal of Medical Entomology Vol. 60, No. 1 ( 2023-01-12), p. 202-212
    Details
    In: Journal of Medical Entomology, Oxford University Press (OUP), Vol. 60, No. 1 ( 2023-01-12), p. 202-212
    Abstract: Several sub-Saharan African countries rely on irrigation for food production. This study examined the impact of environmental modifications resulting from irrigation on the ecology of aquatic stages of malaria vectors in a semi-arid region of western Kenya. Mosquito larvae were collected from irrigated and non-irrigated ecosystems during seasonal cross-sectional and monthly longitudinal studies to assess habitat availability, stability, and productivity of anophelines in temporary, semipermanent, and permanent habitats during the dry and wet seasons. The duration of habitat stability was also compared between selected habitats. Emergence traps were used to determine the daily production of female adult mosquitoes from different habitat types. Malaria vectors were morphologically identified and sibling species subjected to molecular analysis. Data was statistically compared between the two ecosystems. After aggregating the data, the overall malaria vector productivity for habitats in the two ecosystems was estimated. Immatures of the malaria vector (Anopheles arabiensis) Patton (Diptera: Culicidae) comprised 98.3% of the Anopheles in both the irrigated and non-irrigated habitats. The irrigated ecosystem had the most habitats, higher larval densities, and produced 85.8% of emerged adult females. These results showed that irrigation provided conditions that increased habitat availability, stability, and diversity, consequently increasing the An. arabiensis production and potential risk of malaria transmission throughout the year. The irrigated ecosystems increased the number of habitats suitable for Anopheles breeding by about 3-fold compared to non-irrigated ecosystems. These results suggest that water management in the irrigation systems of western Kenya would serve as an effective method for malaria vector control.
    Type of Medium: Online Resource
    ISSN: 0022-2585 , 1938-2928
    URL: Article
    DOI: 10.1093/jme/tjac168
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2023
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  • 4
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    Insecticide resistance status of Anopheles arabiensis in irrigated and non-irrigated areas in western Kenya
    Springer Science and Business Media LLC ; 2021
    In:  Parasites & Vectors Vol. 14, No. 1 ( 2021-06-26)
    Details
    In: Parasites & Vectors, Springer Science and Business Media LLC, Vol. 14, No. 1 ( 2021-06-26)
    Abstract: Malaria control in Kenya is based on case management and vector control using long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS). However, the development of insecticide resistance compromises the effectiveness of insecticide-based vector control programs. The use of pesticides for agricultural purposes has been implicated as one of the sources driving the selection of resistance. The current study was undertaken to assess the status and mechanism of insecticide resistance in malaria vectors in irrigated and non-irrigated areas with varying agrochemical use in western Kenya. Methods The study was carried out in 2018–2019 in Homa Bay County, western Kenya. The bioassay was performed on adults reared from larvae collected from irrigated and non-irrigated fields in order to assess the susceptibility of malaria vectors to different classes of insecticides following the standard WHO guidelines. Characterization of knockdown resistance ( kdr ) and acetylcholinesterase-inhibiting enzyme/angiotensin-converting enzyme ( Ace-1 ) mutations within Anopheles gambiae s.l. species was performed using the polymerase chain reaction (PCR) method. To determine the agricultural and public health insecticide usage pattern, a questionnaire was administered to farmers, households, and veterinary officers in the study area. Results Anopheles arabiensis was the predominant species in the irrigated (100%, n  = 154) area and the dominant species in the non-irrigated areas (97.5%, n  = 162), the rest being An. gambiae sensu stricto. In 2018, Anopheles arabiensis in the irrigated region were susceptible to all insecticides tested, while in the non-irrigated region reduced mortality was observed (84%) against deltamethrin. In 2019, phenotypic mortality was decreased (97.8–84% to 83.3–78.2%). In contrast, high mortality from malathion (100%), DDT (98.98%), and piperonyl butoxide (PBO)-deltamethrin (100%) was observed. Molecular analysis of the vectors from the irrigated and non-irrigated areas revealed low levels of leucine-serine/phenylalanine substitution at position 1014 (L1014S/L1014F), with mutation frequencies of 1–16%, and low-frequency mutation in the Ace-1 R gene (0.7%). In addition to very high coverage of LLINs impregnated with pyrethroids and IRS with organophosphate insecticides, pyrethroids were the predominant chemical class of pesticides used for crop and animal protection. Conclusion Anopheles arabiensis from irrigated areas showed increased phenotypic resistance, and the intensive use of pesticides for crop protection in this region may have contributed to the selection of resistance genes observed. The susceptibility of these malaria vectors to organophosphates and PBO synergists in pyrethroids offers a promising future for IRS and insecticide-treated net-based vector control interventions. These findings emphasize the need for integrated vector control strategies, with particular attention to agricultural practices to mitigate mosquito resistance to insecticides. Graphic abstract
    Type of Medium: Online Resource
    ISSN: 1756-3305
    URL: Article
    DOI: 10.1186/s13071-021-04833-z
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
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  • 5
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    Risk associations of submicroscopic malaria infection in lakeshore, plateau and highland areas of Kisumu County in western Kenya
    Public Library of Science (PLoS) ; 2022
    In:  PLOS ONE Vol. 17, No. 5 ( 2022-5-16), p. e0268463-
    Details
    In: PLOS ONE, Public Library of Science (PLoS), Vol. 17, No. 5 ( 2022-5-16), p. e0268463-
    Abstract: Persons with submicroscopic malaria infection are a major reservoir of gametocytes that sustain malaria transmission in sub-Saharan Africa. Despite recent decreases in the national malaria burden in Kenya due to vector control interventions, malaria transmission continues to be high in western regions of the country bordering Lake Victoria. The objective of this study was to advance knowledge of the topographical, demographic and behavioral risk factors associated with submicroscopic malaria infection in the Lake Victoria basin in Kisumu County. Methods Cross-sectional community surveys for malaria infection were undertaken in three eco-epidemiologically distinct zones in Nyakach sub-County, Kisumu. Adjacent regions were topologically characterized as lakeshore, hillside and highland plateau. Surveys were conducted during the 2019 and 2020 wet and dry seasons. Finger prick blood smears and dry blood spots (DBS) on filter paper were collected from 1,777 healthy volunteers for microscopic inspection and real time-PCR (RT-PCR) diagnosis of Plasmodium infection. Persons who were PCR positive but blood smear negative were considered to harbor submicroscopic infections. Topographical, demographic and behavioral risk factors were correlated with community prevalence of submicroscopic infections. Results Out of a total of 1,777 blood samples collected, 14.2% (253/1,777) were diagnosed as submicroscopic infections. Blood smear microscopy and RT-PCR, respectively, detected 3.7% (66/1,777) and 18% (319/1,777) infections. Blood smears results were exclusively positive for P . falciparum , whereas RT-PCR also detected P . malariae and P . ovale mono- and co-infections. Submicroscopic infection prevalence was associated with topographical variation (χ 2 = 39.344, df = 2, p 〈 0.0001). The highest prevalence was observed in the lakeshore zone (20.6%, n = 622) followed by the hillside (13.6%, n = 595) and highland plateau zones (7.9%, n = 560). Infection prevalence varied significantly according to season (χ 2 = 17.374, df = 3, p 〈 0.0001). The highest prevalence was observed in residents of the lakeshore zone in the 2019 dry season (29.9%, n = 167) and 2020 and 2019 rainy seasons (21.5%, n = 144 and 18.1%, n = 155, respectively). In both the rainy and dry seasons the likelihood of submicroscopic infection was higher in the lakeshore (AOR: 2.71, 95% CI = 1.85–3.95; p 〈 0.0001) and hillside (AOR: 1.74, 95% CI = 1.17–2.61, p = 0.007) than in the highland plateau zones. Residence in the lakeshore zone ( p 〈 0.0001), male sex ( p = 0.025), school age ( p = 0.002), and living in mud houses ( p = 0.044) increased the risk of submicroscopic malaria infection. Bed net use ( p = 0.112) and occupation ( p = 0.116) were not associated with submicroscopic infection prevalence. Conclusion Topographic features of the local landscape and seasonality are major correlates of submicroscopic malaria infection in the Lake Victoria area of western Kenya. Diagnostic tests more sensitive than blood smear microscopy will allow for monitoring and targeting geographic sites where additional vector interventions are needed to reduce malaria transmission.
    Type of Medium: Online Resource
    ISSN: 1932-6203
    URL: Article
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    DOI: 10.1371/journal.pone.0268463
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    DOI: 10.1371/journal.pone.0268463.t001
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    DOI: 10.1371/journal.pone.0268463.s001
    DOI: 10.1371/journal.pone.0268463.s002
    Language: English
    Publisher: Public Library of Science (PLoS)
    Publication Date: 2022
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  • 6
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    A prospective cohort study of Plasmodium falciparum malaria in three sites of Western Kenya
    Springer Science and Business Media LLC ; 2022
    In:  Parasites & Vectors Vol. 15, No. 1 ( 2022-11-09)
    Details
    In: Parasites & Vectors, Springer Science and Business Media LLC, Vol. 15, No. 1 ( 2022-11-09)
    Abstract: Malaria in western Kenya is currently characterized by sustained high Plasmodial transmission and infection resurgence, despite positive responses in some areas following intensified malaria control interventions since 2006. This study aimed to evaluate long-term changes in malaria transmission profiles and to assess patterns of asymptomatic malaria infections in school children aged 5–15 years at three sites in western Kenya with heterogeneous malaria transmission and simultaneous malaria control interventions. Methods The study was conducted from 2018 to 2019 and is based on data taken every third year from 2005 to 2014 during a longitudinal parasitological and mosquito adult surveillance and malaria control programme that was initiated in 2002 in the villages of Kombewa, Iguhu, and Marani. Plasmodium spp. infections were determined using microscopy. Mosquito samples were identified to species and host blood meal source and sporozoite infections were assayed using polymerase chain reaction. Results Plasmodium falciparum was the only malaria parasite evaluated during this study (2018–2019). Asymptomatic malaria parasite prevalence in school children decreased in all sites from 2005 to 2008. However, since 2011, parasite prevalence has resurged by  〉  40% in Kombewa and Marani. Malaria vector densities showed similar reductions from 2005 to 2008 in all sites, rose steadily until 2014, and decreased again. Overall, Kombewa had a higher risk of infection compared to Iguhu ( χ 2  = 552.52, df  = 1, P   〈  0.0001) and Marani ( χ 2  = 1127.99, df  = 1, P   〈  0.0001). There was a significant difference in probability of non-infection during malaria episodes (log-rank test, χ 2  = 617.59, df  = 2, P   〈  0.0001) in the study sites, with Kombewa having the least median time of non-infection during malaria episodes. Gender bias toward males in infection was observed ( χ 2  = 27.17, df  = 1, P   〈  0.0001). The annual entomological inoculation rates were 5.12, 3.65, and 0.50 infective bites/person/year at Kombewa, Iguhu, and Marani, respectively, during 2018 to 2019. Conclusions Malaria prevalence in western Kenya remains high and has resurged in some sites despite continuous intervention efforts. Targeting malaria interventions to those with asymptomatic infections who serve as human reservoirs might decrease malaria transmission and prevent resurgences. Longitudinal monitoring enables detection of changes in parasitological and entomological profiles and provides core baseline data for the evaluation of vector interventions and guidance for future planning of malaria control. Graphical abstract
    Type of Medium: Online Resource
    ISSN: 1756-3305
    URL: Article
    DOI: 10.1186/s13071-022-05503-4
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
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  • 7
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    Signatures of selection and drivers for novel mutation on transmission-blocking vaccine candidate Pfs25 gene in western Kenya
    Public Library of Science (PLoS) ; 2022
    In:  PLOS ONE Vol. 17, No. 4 ( 2022-4-7), p. e0266394-
    Details
    In: PLOS ONE, Public Library of Science (PLoS), Vol. 17, No. 4 ( 2022-4-7), p. e0266394-
    Abstract: Leading transmission-blocking vaccine candidates such as Plasmodium falciparum surface protein 25 ( Pfs25 gene) may undergo antigenic alterations which may render them ineffective or allele-specific. This study examines the level of genetic diversity, signature of selection and drivers of Pfs25 polymorphisms of parasites population in regions of western Kenya with varying malaria transmission intensities. Methods Dry blood spots (DBS) were collected in 2018 and 2019 from febrile outpatients with malaria at health facilities in malaria-endemic areas of Homa Bay, Kisumu (Chulaimbo) and the epidemic-prone highland area of Kisii. Parasites DNA were extracted from DBS using Chelex method. Species identification was performed using real-time PCR. The 460 base pairs (domains 1–4) of the Pfs25 were amplified and sequenced for a total of 180 P . falciparum -infected blood samples. Results Nine of ten polymorphic sites were identified for the first time. Overall, Pfs25 exhibited low nucleotide diversity (0.04×10 −2 ) and low mutation frequencies (1.3% to 7.7%). Chulaimbo had the highest frequency (15.4%) of mutated sites followed by Kisii (6.7%) and Homa Bay (5.1%). Neutrality tests of Pfs25 variations showed significant negative values of Tajima’s D (-2.15, p 〈 0.01) and Fu’s F (-10.91, p 〈 0.001) statistics tests. Three loci pairs (123, 372), (364, 428) and (390, 394) were detected to be under linkage disequilibrium and none had history of recombination. These results suggested that purifying selection and inbreeding might be the drivers of the observed variation in Pfs25 . Conclusion Given the low level of nucleotide diversity, it is unlikely that a Pfs25 antigen-based vaccine would be affected by antigenic variations. However, continued monitoring of Pfs25 immunogenic domain 3 for possible variants that might impact vaccine antibody binding is warranted.
    Type of Medium: Online Resource
    ISSN: 1932-6203
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    DOI: 10.1371/journal.pone.0266394
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    DOI: 10.1371/journal.pone.0266394.s005
    Language: English
    Publisher: Public Library of Science (PLoS)
    Publication Date: 2022
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  • 8
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    Community case management of malaria in Western Kenya: performance of community health volunteers in active malaria case surveillance
    Springer Science and Business Media LLC ; 2023
    In:  Malaria Journal Vol. 22, No. 1 ( 2023-03-08)
    Details
    In: Malaria Journal, Springer Science and Business Media LLC, Vol. 22, No. 1 ( 2023-03-08)
    Abstract: In western Kenya, not all malaria cases are reported as stipulated in the community case management of malaria (CCMm) strategy. This underreporting affects the equity distribution of malaria commodities and the evaluation of interventions. The current study aimed to evaluate the effectiveness of community health volunteers’ active case detection and management of malaria in western Kenya. Methods Cross-sectional active case detection (ACD) of malaria survey was carried out between May and August 2021 in three eco-epidemiologically distinct zones in Kisumu, western Kenya: Kano Plains, Lowland lakeshore and Highland Plateau. The CHVs conducted biweekly ACD of malaria household visits to interview and examine residents for febrile illness. The Community Health Volunteers (CHVs) performance during the ACD of malaria was observed and interviews done using structured questionnaires. Results Of the total 28,800 surveyed, 2597 (9%) had fever and associated malaria symptoms. Eco-epidemiological zones, gender, age group, axillary body temperature, bed net use, travel history, and survey month all had a significant association with malaria febrile illness (p  〈  0.05). The qualification of the CHV had a significant influence on the quality of their service. The number of health trainings received by the CHVs was significantly related to the correctness of using job aid (χ 2  = 6.261, df = 1, p  = 0.012) and safety procedures during the ACD activity (χ 2  = 4.114, df = 1, p  = 0.043). Male CHVs were more likely than female CHVs to correctly refer RDT-negative febrile residents to a health facility for further treatment (OR = 3.94, 95% CI = 1.85–5.44, p   〈  0.0001). Most of RDT-negative febrile residents who were correctly referred to the health facility came from the clusters with a CHV having 10 years of experience or more (OR = 1.29, 95% CI = 1.05–1.57, p  = 0.016). Febrile residents in clusters managed by CHVs with more than 10 years of experience (OR = 1.82, 95% CI = 1.43–2.31, p   〈  0.0001), who had a secondary education (OR = 1.53, 95% CI = 1.27–1.85, p  〈  0.0001), and were over the age of 50 (OR = 1.44, 95% CI = 1.18–1.76, p   〈  0.0001), were more likely to seek malaria treatment in public hospitals. All RDT positive febrile residents were given anti-malarial by the CHVs, and RDT negatives were referred to the nearest health facility for further treatment. Conclusions The CHV’s years of experience, education level, and age had a significant influence on their service quality. Understanding the qualifications of CHVs can assist healthcare systems and policymakers in designing effective interventions that assist CHVs in providing high-quality services to their communities.
    Type of Medium: Online Resource
    ISSN: 1475-2875
    URL: Article
    DOI: 10.1186/s12936-023-04523-4
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2023
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  • 9
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    Asymptomatic and submicroscopic Plasmodium infections in an area before and during integrated vector control in Homa Bay, western Kenya
    Springer Science and Business Media LLC ; 2022
    In:  Malaria Journal Vol. 21, No. 1 ( 2022-09-24)
    Details
    In: Malaria Journal, Springer Science and Business Media LLC, Vol. 21, No. 1 ( 2022-09-24)
    Abstract: Long-lasting insecticidal nets (LLINs) have been the primary vector control strategy until indoor residual spraying (IRS) was added in Homa Bay and Migori Counties in western Kenya. The objective of this study was to evaluate the impact of LLINs integrated with IRS on the prevalence of asymptomatic and submicroscopic Plasmodium infections in Homa Bay County. Methods A two-stage cluster sampling procedure was employed to enroll study participants aged ≥ 6 months old. Four consecutive community cross-sectional surveys for Plasmodium infection were conducted in residents of Homa Bay county, Kenya. Prior to the start of the study, all study households received LLINs, which were distributed between June 2017 and March 2018. The first (February 2018) and second (June 2018) surveys were conducted before and after the first round of IRS (Feb–Mar 2018), while the third (February 2019) and fourth (June 2019) surveys were conducted before and after the second application of IRS (February–March 2019). Finger-prick blood samples were obtained to prepare thick and thin smears for microscopic determination and qPCR diagnosis of Plasmodium genus. Results Plasmodium spp. infection prevalence by microscopy was 18.5% (113/610) before IRS, 14.2% (105/737) and 3.3% (24/720) after the first round of IRS and 1.3% (11/849) after the second round of IRS (p  〈  0.0001). Submicroscopic (blood smear negative, qPCR positive) parasitaemia reduced from 18.9% (115/610) before IRS to 5.4% (46/849) after IRS (p  〈  0.0001). However, the proportion of PCR positive infections that were submicroscopic increased from 50.4% (115/228) to 80.7% (46/57) over the study period (p  〈  0.0001). Similarly, while the absolute number and proportions of microscopy positives which were asymptomatic decreased from 12% (73/610) to 1.2% (9/849) (p  〈  0.0001), the relative proportion increased. Geometric mean density of P. falciparum parasitaemia decreased over the 2-year study period (p  〈  0.0001). Conclusions These data suggest that two annual rounds of IRS integrated with LLINs significantly reduced the prevalence of Plasmodium parasitaemia, while the proportion of asymptomatic and submicroscopic infections increased. To reduce cryptic P. falciparum transmission and improve malaria control, strategies aimed at reducing the number of asymptomatic and submicroscopic infections should be considered.
    Type of Medium: Online Resource
    ISSN: 1475-2875
    URL: Article
    DOI: 10.1186/s12936-022-04288-2
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
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  • 10
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    Hyper-prevalence of submicroscopic Plasmodium falciparum infections in a rural area of western Kenya with declining malaria cases
    Springer Science and Business Media LLC ; 2021
    In:  Malaria Journal Vol. 20, No. 1 ( 2021-12-20)
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    In: Malaria Journal, Springer Science and Business Media LLC, Vol. 20, No. 1 ( 2021-12-20)
    Abstract: The gold standard for diagnosing Plasmodium falciparum infection is microscopic examination of Giemsa-stained peripheral blood smears. The effectiveness of this procedure for infection surveillance and malaria control may be limited by a relatively high parasitaemia detection threshold. Persons with microscopically undetectable infections may go untreated, contributing to ongoing transmission to mosquito vectors. The purpose of this study was to determine the magnitude and determinants of undiagnosed submicroscopic P. falciparum infections in a rural area of western Kenya. Methods A health facility-based survey was conducted, and 367 patients seeking treatment for symptoms consistent with uncomplicated malaria in Homa Bay County were enrolled. The frequency of submicroscopic P. falciparum infection was measured by comparing the prevalence of infection based on light microscopic inspection of thick blood smears versus real-time polymerase chain reaction (RT-PCR) targeting P. falciparum 18S rRNA gene. Long-lasting insecticidal net (LLIN) use, participation in nocturnal outdoor activities, and gender were considered as potential determinants of submicroscopic infections. Results Microscopic inspection of blood smears was positive for asexual P. falciparum parasites in 14.7% (54/367) of cases. All of these samples were confirmed by RT-PCR. 35.8% (112/313) of blood smear negative cases were positive by RT-PCR, i.e., submicroscopic infection, resulting in an overall prevalence by RT-PCR alone of 45.2% compared to 14.7% for blood smear alone. Females had a higher prevalence of submicroscopic infections (35.6% or 72 out of 202 individuals, 95% CI 28.9–42.3) compared to males (24.2%, 40 of 165 individuals, 95% CI 17.6–30.8). The risk of submicroscopic infections in LLIN users was about half that of non-LLIN users (OR = 0.59). There was no difference in the prevalence of submicroscopic infections of study participants who were active in nocturnal outdoor activities versus those who were not active (OR = 0.91). Patients who participated in nocturnal outdoor activities and use LLINs while indoors had a slightly higher risk of submicroscopic infection than those who did not use LLINs (OR = 1.48). Conclusion Microscopic inspection of blood smears from persons with malaria symptoms for asexual stage P. falciparum should be supplemented by more sensitive diagnostic tests in order to reduce ongoing transmission of P. falciparum parasites to local mosquito vectors.
    Type of Medium: Online Resource
    ISSN: 1475-2875
    URL: Article
    DOI: 10.1186/s12936-021-04012-6
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2021
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