Are members of the Anopheles fluviatilis complex conspecific?

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.

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Bionomics of Anopheles fluviatilis and Anopheles culicifacies (Diptera: Culicidae) in Relation to Malaria Transmission in East-Central India

Journal of Medical Entomology ◽

10.1093/jme/tjx065 ◽

2017 ◽

Vol 54 (4) ◽

pp. 821-830 ◽

Cited By ~ 13

Author(s):

S. S. Sahu ◽

K. Gunasekaran ◽

N. Krishnamoorthy ◽

P. Vanamail ◽

A Mathivanan ◽

...

Keyword(s):

Malaria Transmission ◽

Central India ◽

Anopheles Culicifacies ◽

East Central ◽

Anopheles Fluviatilis

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The Comparative Effectiveness of Adult Mosquito Sampling Methods Dealing With Odor-Baited Resting Box Traps in A Malaria-Endemic Area in Southern Iran

10.21203/rs.3.rs-860994/v1 ◽

2021 ◽

Author(s):

Seyed Hassan Moosa Kazemi ◽

Yousef Salari ◽

Nariman Shahosseini ◽

Sajad Fekri ◽

Ahmad Raeisi ◽

...

Keyword(s):

Culex Pipiens ◽

Anopheles Stephensi ◽

Sampling Methods ◽

Adult Mosquito ◽

Surveillance Systems ◽

Malaria Endemic Area ◽

Entomological Surveillance ◽

Anopheles Fluviatilis ◽

Mosquito Sampling ◽

Bandar Abbas

Abstract Background Iran is under threat of a potential outbreak of mosquito-borne diseases, such as malaria, Dengue fever, Chikungunya, and Zika. The study aimed to determine the efficiency and sustainability of some adult mosquito sampling methods for designing effective entomological surveillance systems in a malaria endemic area. Methods Different rates of tap water, sugar, and yeast (Saccharomyces cerevisiae) were mixed to provide CO2. Anopheles stephensi and Culex pipiens Bandar Abbas strains were reared in the insectary and used for tests. On a lab scale, CO2 orientation experiments were performed using a Y-tube olfactometer on the insectary mosquito strains. In the field trial, human landing catches (HLC), artificial pit shelter (APS), CO2-baited trap (CO2-BT), human and cow odor baited resting boxes (HOBT, COBT), cow urine baited trap (CUBT), and colored un-baited box (UB) were studied in Bandar Abbas, Hormozgan Province, south of Iran. Mean densities of An. stephensi and Cx. pipiens insectary strains, which oriented to CO2 as flowrate of 170, and 300 mL/minute was significantly higher compared to the control group (P < 0.05). The black un-baited inbox resting traps significantly more collected wild mosquito species compared to others colored UB (P ˂ 0.05). Results A total of 2722 collected mosquitoes comprises Culex pipiens (48.56%), Anopheles fluviatilis s.l.(14.21%), An. stephensi (11.68%), Cx. theileri (9.95%), Aedes caspius (7.01%), An. dthali (6.79%) An. culicifacies s.l., An. pulcherrimus, An. sergentii,An. superpictus s.l., Cx. sitiens and, Ae.caspius less than 1%. Anopheles stephensi and, An.sergenti were most collected in CUBT. Anopheles fluviatilis s.l. and Ae. caspius were most found in HLC. Anopheles dthali, Cx. pipiens and, Cx. theileri were most abundant in APS. Conclusions Black CUBT and APS methods can be suggested as a perfect sampling strategy for malaria vectors surveillance. APS, and HLC methods were found useful to entomological surveillance systems for arboviral and filarial vector-borne diseases. Further modified sampling methods should be devoted to identify more effective sampling methods.

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The Comparative Effectiveness of Adult Mosquito Sampling Methods Dealing With Odor-baited Resting Box Traps in a Malaria-endemic Area in Southern Iran

10.21203/rs.3.rs-860994/v2 ◽

2021 ◽

Author(s):

Seyed Hassan Moosa Kazemi ◽

Yousef Salari ◽

Nariman Shahosseini ◽

Sajad Fekri ◽

Ahmad Raeisi ◽

...

Keyword(s):

Culex Pipiens ◽

Anopheles Stephensi ◽

Sampling Methods ◽

Adult Mosquito ◽

Surveillance Systems ◽

Malaria Endemic Area ◽

Entomological Surveillance ◽

Anopheles Fluviatilis ◽

Mosquito Sampling ◽

Bandar Abbas

Abstract BackgroundIran is under threat of a potential outbreak of mosquito-borne diseases, such as malaria, Dengue fever, Chikungunya, and Zika. The study aimed to determine the efficiency and sustainability of some adult mosquito sampling methods for designing effective entomological surveillance systems in a malaria endemic area.MethodsDifferent rates of tap water, sugar, and yeast (Saccharomyces cerevisiae) were mixed to provide CO2. Anopheles stephensi and Culex pipiens Bandar Abbas strains were reared in the insectary and used for tests. On a lab scale, CO2 orientation experiments were performed using a Y-tube olfactometer on the insectary mosquito strains. In the field trial, human landing catches (HLC), artificial pit shelter (APS), CO2-baited trap (CO2-BT), human and cow odor baited resting boxes (HOBT, COBT), cow urine baited trap (CUBT), and colored un-baited box (UB) were studied in Bandar Abbas, Hormozgan Province, south of Iran. Mean densities of An. stephensi and Cx. pipiens insectary strains, which oriented to CO2 as flowrate of 170, and 300 mL/minute was significantly higher compared to the control group (P < 0.05). The black un-baited inbox resting traps significantly more collected wild mosquito species compared to others colored UB (P ˂ 0.05). ResultsA total of 2722 collected mosquitoes comprises Culex pipiens (48.56%), Anopheles fluviatilis s.l.(14.21%), An. stephensi (11.68%), Cx. theileri (9.95%), Aedes caspius (7.01%), An. dthali (6.79%) An. culicifacies s.l. , An. pulcherrimus, An. sergentii,An. superpictus s.l., Cx. sitiens and, Ae.caspius less than 1%. Anopheles stephensi and, An.sergenti were most collected in CUBT. Anopheles fluviatilis s.l. and Ae. caspius were most found in HLC. Anopheles dthali, Cx. pipiens and, Cx. theileri were most abundant in APS. ConclusionsBlack CUBT and APS methods can be suggested as a perfect sampling strategy for malaria vectors surveillance. APS, and HLC methods were found useful to entomological surveillance systems for arboviral and filarial vector-borne diseases. Further modified sampling methods should be devoted to identify more effective sampling methods.

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