Anopheles bwambae sp.n., a malaria vector in the Semliki Valley, Uganda, and its relationships with other sibling species of the An.gambiae complex (Diptera: Culicidae)

1985 ◽  
Vol 10 (4) ◽  
pp. 501-522 ◽  
Author(s):  
G. B. WHITE
2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Ashok K. Mishra ◽  
Praveen K. Bharti ◽  
Anup Vishwakarma ◽  
Sekh Nisar ◽  
Harsh Rajvanshi ◽  
...  

Abstract Background Understanding of malaria vector density, distribution, insecticide resistance, vector incrimination, infection status, and identification of sibling species are some of the essential components of vector control measures for achieving malaria elimination goals. Methods As part of the malaria elimination demonstration project, entomological surveillance was carried out from October 2017 to October 2019 by collecting indoor resting mosquitoes using hand catch method. Susceptibility test was done for determining the insecticide resistance status of vector mosquito Anopheles culicifacies using standard protocols by the World Health Organization. The cone bioassay method was used for determining the efficacy and quality of insecticide sprayed. Mosquitoes collected from different ecotypes were identified and processed for parasite identification, vector incrimination and sibling species determination. Results The two known malaria vector species (Anopheles culicifacies and Anopheles fluviatilis) were found in the study area, which have been previously reported in this and adjoining areas of the State of Madhya Pradesh. The prevalence of An. culicifacies was significantly higher in all study villages with peak in July while lowest number was recorded in May. Proportion of vector density was observed to be low in foothill terrains. The other anopheline species viz, Anopheles subpictus, Anopheles annularis, Anopheles vagus, Anopheles splendidus, Anopheles pallidus, Anopheles nigerrimus and Anopheles barbirostris were also recorded in the study area, although their prevalence was significantly less compared to the An. culicifacies. In 2017, An. culicifacies was found to be resistant to dichloro-diphenyl-trichloroethane (DDT) and malathion, with possible resistance to alphacypermethrin and susceptible to deltamethrin. However, in 2019, the species was found to be resistant to alphacypermethrin, DDT, malathion, with possible resistance to deltamethrin. The bioassays revealed 82 to > 98% corrected % mortality of An. culicifacies on day-one post-spraying and 35 to 62% on follow-up day-30. Anopheles culicifacies sibling species C was most prevalent (38.5%) followed by A/D and E while B was least pre-dominant (11.9%). Anopheles fluviatilis sibling species T was most prevalent (74.6%) followed by U (25.4%) while species S was not recorded. One An.culicifacies (sibling species C) was found positive for Plasmodium falciparum by PCR tests in the mosquitoes sampled from the test areas. Conclusion Based on the nine entomologic investigations conducted between 2017–2019, it was concluded that An. culicifacies was present throughout the year while An. fluviatilis had seasonal presence in the study areas. Anopheles culicifacies was resistant to alphacypermethrin and emerging resistance to deltamethrin was observed in this area. Anopheles culicifacies was confirmed as the malaria vector. This type of information on indigenous malaria vectors and insecticide resistance is important in implementation of vector control through indoor residual spraying (IRS) and use of insecticide-impregnated bed nets for achieving the malaria elimination goals.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jewelna Akorli ◽  
Esinam Abla Akorli ◽  
Seraphim Naa Afoley Tetteh ◽  
Godwin Kwame Amlalo ◽  
Millicent Opoku ◽  
...  

AbstractA vertically transmitted microsporidian, Microsporidia MB, with the ability to disrupt Plasmodium development was reported in Anopheles arabiensis from Kenya, East Africa. To demonstrate its range of incidence, archived DNA samples from 7575 Anopheles mosquitoes collected from Ghana were screened. MB prevalence was observed at 1.8%. An. gambiae s.s constituted 87% of positive mosquitoes while the remaining were from An. coluzzii. Both sibling species had similar positivity rates (24% and 19%; p = 0.42) despite the significantly higher number of An. gambiae s.s analysed (An. gambiae s.s = 487; An. coluzzii = 94; p = 0.0005). The microsporidian was also more prevalent in emerged adults from field-collected larvae than field-caught adults (p < 0.0001) suggestive of an efficient vertical transmission and/or horizontal transfer among larvae. This is the first report of Microsporidia MB in Anopheles mosquitoes in West Africa. It indicates possible widespread among malaria vector species and warrants investigations into the symbiont’s diversity across sub-Saharan Africa.


Heredity ◽  
2015 ◽  
Vol 115 (5) ◽  
pp. 471-479 ◽  
Author(s):  
H A Smith ◽  
B J White ◽  
P Kundert ◽  
C Cheng ◽  
J Romero-Severson ◽  
...  

2000 ◽  
Vol 14 (4) ◽  
pp. 437-440 ◽  
Author(s):  
S. N. Surendran ◽  
T. A. Abhayawardana ◽  
B. G. D. N. K. De Silva ◽  
R. Ramasamy ◽  
M. S. Ramasamy

2015 ◽  
Vol 47 (3) ◽  
pp. 79 ◽  
Author(s):  
S. Sande ◽  
M. Zimba ◽  
P. Chinwada ◽  
H.T. Masendu ◽  
A. Makuwaza

Regular entomological monitoring is important to determine changes in mosquito species composition and relative densities of malaria vectors in relation to vector control interventions. A study to gain insights into malaria vector species composition and relative abundance was undertaken in Mutare and Mutasa districts, Zimbabwe. Two methods; indoor resting catches and larval sampling were used to collect indoor resting adults and larvae from May 2013 to April 2014. Mosquitoes collected as adults and reared from larvae that were identified morphologically as potential malaria vectors were further processed to sibling species by polymerase chain reaction (PCR). Morphological identification of anopheline mosquitoes showed presence of two complexes: <em>An. funestus</em> and <em>An. gambiae</em>. The total number of female members of the <em>An. funestus</em> group and <em>An. gambiae</em> complex collected by both methods from the two sites was 840 and 31 respectively. Malaria vector species of both complexes were more abundant in Mutare than in Mutasa. The PCR-based assays showed the presence of four sibling species: <em>An. funestus</em> <em>sensu</em> <em>stricto</em> (90.8%, 267/294) and <em>An. leesoni</em> (5.1%, 15/294), of <em>An. funestus</em> group; <em>An. arabiensis</em> (41.9%, 13/31) and <em>An. quadriannulatus</em> (48.4%, 15/31) of the <em>An. gambiae</em> complex. About 4% and 5% of specimens of <em>An. gambiae</em> complex and A<em>n. funestus</em> group respectively did not amplify. Of the two identified malaria vector sibling species, An. funestus sensu stricto was more abundant (95.4%, 267/280) than <em>An. arabiensis</em> (4.6%, 13/280), suggesting the replacement to secondary vector of <em>An. arabiensis</em>, which was previously the predominant vector species. <em>An. funestus</em> <em>sensu</em> <em>stricto</em> and <em>An</em>. <em>arabiensis</em>, the most important vectors of human malaria were identified in this study, but their resting and biting habits as well as insecticide susceptibility are unclear. Further studies on vector behaviour are therefore recommended.


2020 ◽  
Author(s):  
Varun Tyagi ◽  
Diganta Goswami ◽  
Sunil Dhiman ◽  
Dipanjan Dey ◽  
Bipul Rabha ◽  
...  

ABSTRACTBackgroundVector borne infectious diseases affect two third of the world’s human population and cause mortality in millions each year. Malaria remains one of the major killers in the Indian sub-continent and transmitted uninterruptedly by many efficient vectors and their sibling species. In North East India (NE), Anopheles minimus has been recognized as an important vector which shares majority of malaria cases. This study primarily focuses on to recognize the presence and distribution of sibling species of An. minimus in certain endemic area of NE India.MethodsAnopheles species were collected and identified using available morphological keys. The genomic DNA was extracted from the mosquito specimen and used to perform species specific PCR (ss PCR) for molecular identification of major malaria vector An. minimus sibling speciesResultMorphological identification suggested the presence of An. minimus sl in low density in the study area. The specimen of An. minimus subjected to ss PCR confirmed the prevalence of only one sibling species namely, An. minimus A in Sialmari and Chandubi.ConclusionThough in low density, but malaria vector An. minimus is still present in certain endemic areas of NE India. The ss PCR assay employed presently suggested that An. minimus sibling species A is prevailing in the region. Presently used ss PCR assay was simpler, faster, cheaper and more readily interpreted than earlier assays. This information could be useful in understanding of current prevalence and distribution of An. minimus sibling species complex in NE region of India.


Genome ◽  
2000 ◽  
Vol 43 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Corália C.L. Ramírez ◽  
Eliana M.B. Dessen

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