Comment on: Emergence of the invasive malaria vector Anopheles stephensi in Khartoum State, Central Sudan

Kolaczinski, Jan; Al-Eryani, Samira; Chanda, Emmanuel

doi:10.1186/s13071-021-05080-y

Cited by 3 publications

(1 citation statement)

References 3 publications

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“…The introduction and establishment of a new vector, Anopheles stephensi , were first reported in 2012 [ 13 , 14 ]. Once known as an ‘Asian’ vector, this highly competent Anopheles mosquito is now present throughout the Horn of Africa [ 15 – 17 ]. Anopheles stephensi thrives in urban areas and feeds at dusk, unlike other Anopheles vectors, which prefer to bite late at night [ 16 , 17 ].…”

Section: Introductionmentioning

confidence: 99%

Molecular investigation of malaria-infected patients in Djibouti city (2018–2021)

Moussa

Mze

Arreh

et al. 2023

Malar J

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Background The Republic of Djibouti is a malaria endemic country that was in pre-elimination phase in 2006–2012. From 2013, however, malaria has re-emerged in the country, and its prevalence has been increasing every year. Given the co-circulation of several infectious agents in the country, the assessment of malaria infection based on microscopy or histidine-rich protein 2 (HRP2)-based rapid diagnostic tests (RDT) has shown its limitations. This study, therefore, aimed to assess the prevalence of malaria among febrile patients in Djibouti city using more robust molecular tools. Methods All suspected malaria cases reported to be microscopy-positive were randomly sampled (n = 1113) and included in four health structures in Djibouti city over a 4-year period (2018–2021), mainly during the malaria transmission season (January–May). Socio-demographic information was collected, and RDT was performed in most of the included patients. The diagnosis was confirmed by species-specific nested polymerase chain reaction (PCR). Data were analysed using Fisher’s exact test and kappa statistics. Results In total, 1113 patients with suspected malaria and available blood samples were included. PCR confirmed that 788/1113 (70.8%) were positive for malaria. Among PCR-positive samples, 656 (83.2%) were due to Plasmodium falciparum, 88 (11.2%) Plasmodium vivax, and 44 (5.6%) P. falciparum/P. vivax mixed infections. In 2020, P. falciparum infections were confirmed by PCR in 50% (144/288) of negative RDTs. After the change of RDT in 2021, this percentage decreased to 17%. False negative RDT results were found more frequently (P < 0.05) in four districts of Djibouti city (Balbala, Quartier 7, Quartier 6, and Arhiba). Malaria occurred less frequently in regular bed net users than in non-users (odds ratio [OR]: 0.62, 95% confidence interval [CI]: 0.42–0.92). Conclusions The present study confirmed the high prevalence of falciparum malaria and, to a lesser extent, vivax malaria. Nevertheless, 29% of suspected malaria cases were misdiagnosed by microscopy and/or RDT. There is a need to strengthen the capacity for diagnosis by microscopy and to evaluate the possible role of P. falciparum hrp2 gene deletion, which leads to false negative cases of P. falciparum.

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Section: Introductionmentioning

confidence: 99%

Molecular investigation of malaria-infected patients in Djibouti city (2018–2021)

Moussa

Mze

Arreh

et al. 2023

Malar J

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Prevention

2023

Apicomplexa in Livestock

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Genome structural variants shape adaptive success of an invasive urban malaria vectorAnopheles stephensi

Samano,

Kumar,

Liao

et al. 2024

Preprint

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Global changes are associated with the emergence of several invasive species. However, the genomic determinants of the adaptive success of an invasive species in a new environment remain poorly understood. Genomic structural variants (SVs), consisting of copy number variants, play an important role in adaptation. SVs often cause large adaptive shifts in ecologically important traits, which makes SVs compelling candidates for driving rapid adaptations to environmental changes, which is critical to invasive success. To address this problem, we investigated the role SVs play in the adaptive success of Anopheles stephensi, a primary vector of urban malaria in South Asia and an invasive malaria vector in several South Asian islands and Africa. We collected whole genome sequencing data from 115 mosquitoes from invasive island populations and four locations from mainland India, an ancestral range for the species. We identified 2,988 duplication copy number variants and 16,038 deletions in these strains, with ~50% overlapping genes. SVs are enriched in genomic regions with signatures of selective sweeps in the mainland and invasive island populations, implying a putative adaptive role of SVs. Nearly all high-frequency SVs, including the candidate adaptive variants, in the invasive island populations are present on the mainland, suggesting a major contribution of existing variation to the success of the island populations. Among the candidate adaptive SVs, three duplications involving toxin-resistance genes evolved, likely due to the widespread application of insecticides in India since the 1950s. We also identify two SVs associated with the adaptation of An. stephensi larvae to brackish water in the island and two coastal mainland populations, where the mutations likely originated. Our results suggest that existing SVs play a vital role in the evolutionary success of An. stephensi in new environmental conditions.

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Comment on: Emergence of the invasive malaria vector Anopheles stephensi in Khartoum State, Central Sudan

Cited by 3 publications

References 3 publications

Molecular investigation of malaria-infected patients in Djibouti city (2018–2021)

Molecular investigation of malaria-infected patients in Djibouti city (2018–2021)

Prevention

Genome structural variants shape adaptive success of an invasive urban malaria vectorAnopheles stephensi

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