Mosquito Species Diversity and Malaria Transmission in Ayos, an Area of Degraded Forest Targeted for Universal Long-Lasting Insecticidal Net Distribution in Southern Cameroon

2014 ◽  
Vol 22 (3) ◽  
pp. 602-610 ◽  
Author(s):  
P.N. Akono ◽  
C. Tonga ◽  
S. Kekeunou ◽  
L.G. Lehman
Keyword(s):  
Species Diversity ◽  
Malaria Transmission ◽  
Mosquito Species ◽  
Degraded Forest ◽  
Southern Cameroon

scholarly journals Anopheles ecology, genetics and malaria transmission in northern Cambodia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amélie Vantaux ◽  
Michelle M. Riehle ◽  
Eakpor Piv ◽  
Elise J. Farley ◽  
Sophy Chy ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Mosquito Species ◽  
Rubber Tree ◽  
Amplicon Sequencing ◽  
Forest Sites ◽  
Baited Traps ◽  
Residual Malaria Transmission ◽  
Mosquito Ecology ◽  
Forested Areas ◽  
Greater Mekong Subregion

AbstractIn the Greater Mekong Subregion, malaria cases have significantly decreased but little is known about the vectors or mechanisms responsible for residual malaria transmission. We analysed a total of 3920 Anopheles mosquitoes collected during the rainy and dry seasons from four ecological settings in Cambodia (villages, forested areas near villages, rubber tree plantations and forest sites). Using odor-baited traps, 81% of the total samples across all sites were collected in cow baited traps, although 67% of the samples attracted by human baited traps were collected in forest sites. Overall, 20% of collected Anopheles were active during the day, with increased day biting during the dry season. 3131 samples were identified morphologically as 14 different species, and a subset was also identified by DNA amplicon sequencing allowing determination of 29 Anopheles species. The investigation of well characterized insecticide mutations (ace-1, kdr, and rdl genes) indicated that individuals carried mutations associated with response to all the different classes of insecticides. There also appeared to be a non-random association between mosquito species and insecticide resistance with Anopheles peditaeniatus exhibiting nearly fixed mutations. Molecular screening for Plasmodium sp. presence indicated that 3.6% of collected Anopheles were positive, most for P. vivax followed by P. falciparum. These results highlight some of the key mechanisms driving residual human malaria transmission in Cambodia, and illustrate the importance of diverse collection methods, sites and seasons to avoid bias and better characterize Anopheles mosquito ecology in Southeast Asia.

scholarly journals Plasmodium evasion of mosquito immunity and global malaria transmission: The lock-and-key theory

2015 ◽  
Vol 112 (49) ◽  
pp. 15178-15183 ◽  
Author(s):  
Alvaro Molina-Cruz ◽  
Gaspar E. Canepa ◽  
Nitin Kamath ◽  
Noelle V. Pavlovic ◽  
Jianbing Mu ◽  
...  
Keyword(s):  
Immune System ◽  
Malaria Transmission ◽  
Immune Evasion ◽  
Mosquito Species ◽  
Haplotype Diversity ◽  
Malaria Vectors ◽  
Selective Force ◽  
Genetic Traits ◽  
Geographic Population

Plasmodium falciparum malaria originated in Africa and became global as humans migrated to other continents. During this journey, parasites encountered new mosquito species, some of them evolutionarily distant from African vectors. We have previously shown that the Pfs47 protein allows the parasite to evade the mosquito immune system of Anopheles gambiae mosquitoes. Here, we investigated the role of Pfs47-mediated immune evasion in the adaptation of P. falciparum to evolutionarily distant mosquito species. We found that P. falciparum isolates from Africa, Asia, or the Americas have low compatibility to malaria vectors from a different continent, an effect that is mediated by the mosquito immune system. We identified 42 different haplotypes of Pfs47 that have a strong geographic population structure and much lower haplotype diversity outside Africa. Replacement of the Pfs47 haplotypes in a P. falciparum isolate is sufficient to make it compatible to a different mosquito species. Those parasites that express a Pfs47 haplotype compatible with a given vector evade antiplasmodial immunity and survive. We propose that Pfs47-mediated immune evasion has been critical for the globalization of P. falciparum malaria as parasites adapted to new vector species. Our findings predict that this ongoing selective force by the mosquito immune system could influence the dispersal of Plasmodium genetic traits and point to Pfs47 as a potential target to block malaria transmission. A new model, the “lock-and-key theory” of P. falciparum globalization, is proposed, and its implications are discussed.

Evaluation of species composition and seasonal dynamics of mosquito larvae in the Košice Basin during 2010 and 2011

Biologia ◽  
2013 ◽  
Vol 68 (2) ◽  
Author(s):  
Eva Bocková ◽  
Alica Kočišová ◽  
Helena Hlavatá
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Seasonal Dynamics ◽  
Culex Pipiens ◽  
Mosquito Species ◽  
Mosquito Larvae ◽  
Aedes Vexans ◽  
Anopheles Maculipennis

AbstractIn six sites in the Košice Basin we collected 17,520 larvae of 15 mosquito species during the seasons (April–August) of 2010 and 2011. They were: Aedes vexans (Meigen, 1830), Ae. cinereus (Meigen, 1818) [or Ae. rossicus (Dolbeskin, Gorickaja & Mitrofanova, 1930], Ochlerotatus geniculatus (Olivier, 1791), Oc. refiki (Medschid, 1928), Oc. rusticus (Rossi, 1790), Oc. sticticus (Meigen, 1838), Oc. punctor (Kirby, 1837), Oc. cataphylla (Dyar, 1916), Oc. cantans (Meigen, 1818)[or Oc. annulipes (Meigen, 1830)], Oc. communis (De Geer, 1776), Oc. flavescens (Müller, 1764), Oc. leucomelas (Meigen, 1804), Culiseta annulata (Schrank, 1776), Culex pipiens (L., 1758) [or Cx. torrentium (Martini, 1925)] and Anopheles maculipennis s.l. The objective of the present research was to identify the mosquito larvae species diversity and compare their distribution and density in urban and suburban localities of the monitored territory.

scholarly journals Species diversity and breeding site of mosquito larvae (Diptera: Culicidae) in Macaca fascicularis breeding area

2021 ◽  
Vol 948 (1) ◽  
pp. 012039
Author(s):  
D Novianto ◽  
U K Hadi ◽  
S Soviana ◽  
Supriyono ◽  
H S Darusman
Keyword(s):  
Species Diversity ◽  
Macaca Fascicularis ◽  
Mosquito Species ◽  
Breeding Site ◽  
Mosquito Larvae ◽  
Breeding Sites ◽  
Vector Borne Diseases ◽  
Armigeres Subalbatus ◽  
Vector Borne

Abstract Mosquito larvae play an essential role in the ecological, and many of them can spread human and animal diseases, including in Macaca fascicularis. Information on mosquito species and their habitats can provide an overview of the role of mosquitoes in the spread of vector-borne diseases in M. fascicularis captivity area. This study aimed to identify species diversity of mosquito larvae, species affinity and association, and the larval breeding sites around M. fascicularis captivity area in Bogor, West Java. Mosquito larvae were collected from 102 sites using a 350 ml dipper. Mosquito larvae that were successfully collected consisted of 11 species; Aedes albopictus, Ae. aegypti, Armigeres subalbatus, Anopheles aconitus, An. kochi, An. vagus, Culex fuscocephala, Cx. pseudovishnui, Cx. tritaeniorhyncus, Cx. quinquefasciatus, and Cx. vishnui. Co-occurrence in mosquito larvae as many as 13 compositions, with the highest co-occurrence in Ae. albopictus and Cx. quinquefasciatus that was 11 times. There were seven types breeding sites for the larval mosquitoes, i.e containers, ditches, creeks, ponds, artificial ponds, groundwater puddles, and rice fields. We conclude the existence of mosquito larvae and the availability of their breeding site in M. fascicularis captivity area can be a potential transmission of pathogens between mosquitoes and hosts

scholarly journals Aggressive mosquito fauna and malaria transmission in a forest area targeted for the creation of an agro-industrial complex in the south of Cameroon

2016 ◽  
Vol 48 (3) ◽  
pp. 380
Author(s):  
P. Ntonga Akono ◽  
C. Tonga ◽  
O.E. Ngo Hondt ◽  
M.F. Peka Nsangou ◽  
R. Ngaha ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Indoor Residual Spraying ◽  
Monitoring And Evaluation ◽  
Molecular Techniques ◽  
Industrial Complex ◽  
Degraded Forest ◽  
The South ◽  
Main Road ◽  
The Creation ◽  
The Impact

Baseline entomological information should be collected before the implementation of industrial projects in malaria endemic areas. This allows for subsequent monitoring and evaluation of the project impact on malaria vectors. This study aimed at assessing the vectorial system and malaria transmission in two ecologically different villages of the South-Cameroon forest bloc targeted for the creation of an agro-industrial complex. For four consecutive seasons in 2013, adult mosquitoes were captured using Human Landing Catch in NDELLE village (located along a main road in a degraded forest with many fish ponds) and KOMBO village (located 5km far from the main road in a darker forest and crossed by the Mvobo River). Morpho-taxonomic techniques were used alongside molecular techniques for the identification of mosquito species. ELISA test was used for the detection of circumsporozoite protein antigen of <em>Plasmodium falciparum</em>. Mosquito biting rate was higher in NDELLE than in KOMBO (28.18 <em>versus</em> 17.34 bites per person per night). Mosquitoes had a strong tendency to endophagy both in NDELLE (73.57%) and KOMBO (70.21%). Three anophelines species were identified; <em>An. gambiae</em>, <em>An. funestus</em> s.s and <em>An. moucheti</em> s.s.. <em>An. gambiae</em> and <em>An. funestus</em> s.s. represented the bulk of aggressive mosquitoes in NDELLE (n=10,891; 96.62%). <em>An. gambiae</em> was responsible for 62.6% and 77.72% of malaria transmission in KOMBO and NDELLE respectively. Mean entomological inoculation rate recorded in KOMBO and NDELLE were 4.82 and 2.02 infective bites per person per night respectively. Vector control was mainly based on the use of long-lasting insecticidal nets and indoor residual spraying. The degraded forest environment added to the presence of fishponds resulted in the increase of aggressive mosquito density but not of malaria transmission. The managers should use these data for monitoring and evaluation of the impact of their project; malaria control strategies should be included in their project in order to mitigate the risk of increased malaria transmission as a result of the implementation of their projects.

scholarly journals Low Malaria Transmission in Rosso, an Irrigated Rice-Growing Area in Mauritania

Parasitologia ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 257-268
Author(s):  
Mohamed Aly Ould Lemrabott ◽  
Khadijetou Mint Lekweiry ◽  
Jemila Deida ◽  
Oum Kelthoum Mamadou Djigo ◽  
Mohamed Salem Ould Ahmedou Salem ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Mosquito Species ◽  
Epidemiological Data ◽  
Bed Nets ◽  
Entomological Surveillance ◽  
High Coverage ◽  
Travel History ◽  
Breeding Sites ◽  
Senegal River ◽  
Behavioural Aspects

The construction of dams along the Senegal River resulted in an increase in irrigated land areas and changes in the epidemiology and transmission of water-related diseases. The objective of this study was to update epidemiological data on malaria in Rosso, one of the major Mauritanian cities along the Senegal River. Febrile patients (n = 318) were screened for malaria using a rapid diagnostic test (RDT) for malaria and microscopic examination of blood smears. Diagnosis was later confirmed by polymerase chain reaction (PCR). The mean age of 318 febrile patients was 25.1 (range 1–80 years). Only 7 (2.2%) and 2 (0.6%) had a positive RDT and thick smear, respectively. PCR confirmed the diagnosis in two Plasmodium vivax-infected patients. Most participants (198/318, 62.3%) had no recent travel history outside Rosso. The majority of the febrile patients (90%, 284/311) owned at least one insecticide-treated net (ITN). The frequency of the use of ITNs was not significantly associated with season (rainy vs. dry seasons; p = 0.9) or with the number of ITNs per household (rs = 0.07; n = 285; p = 0.19). Of 285 individuals with ITNs, only two (0.7%) with no travel history were PCR-positive for malaria. Despite the presence of mosquito breeding sites related to rice irrigation, malaria transmission in Rosso remained very low, possibly due to the high coverage and frequent use of bed nets. Regular entomological surveillance for possible changes in the prevalence of Anopheles mosquito species and their behavioural aspects should be implemented.

scholarly journals Molecular Characterization and Genotype Distribution of Thioester-containing Protein 1 Gene, A Key Regulator of Malaria Transmission in An. Gambiae Mosquitoes in Western Kenya

2021 ◽  
Author(s):  
Shirley A. Onyango ◽  
Kevin O. Ochwedo ◽  
Maxwell G. Machani ◽  
Collince J. Omondi ◽  
Isaiah Debrah ◽  
...  
Keyword(s):  
Population Structure ◽  
Anopheles Gambiae ◽  
Malaria Transmission ◽  
Mosquito Species ◽  
Malaria Vectors ◽  
Fixation Index ◽  
Genotype Distribution ◽  
Low Frequencies ◽  
Western Kenya ◽  
Significant Difference

Abstract BackgroundEvolutionary pressures lead to the selection of efficient malaria vectors either resistant or susceptible to Plasmodiumparasites.These forcesmay elevate the introduction of new species genotypes that adapt to new breeding habitats which could have serious implications on malaria transmission.Thioester-containing protein 1 (TEP1) of Anopheles gambiaeplays an important role in innate immune defenses against parasites. This study aims to characterize the distribution pattern of TEP1 polymorphisms determining vector competence and subsequently malaria transmission in western Kenya. MethodsAnopheles gambiaeadult and larvae were collected using pyrethrum spray catches (PSC) and plastic dippers respectivelyfrom Homa Bay, Kakamega, Bungoma, and Kisumu countiesbetween 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 using restriction fragment length polymorphisms-polymerase chain reaction (RFLP-PCR) and to validate the TEP1 genotyping results, a representative sample of alleles was sequenced.ResultsTwo 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 bothin An. gambiaeand An. arabiensis. There was no significant difference detected among the population and between the two mosquito species in TEP1 allele frequency and genotype frequency. The overall low levels in population structure (FST= 0.019) across all sites corresponded to an effective migration index (Nm= 12.571) and lowNei’s genetic distance values (<0.500) among the subpopulation.The comparative fixation index values revealed minimal genetic differentiation between speciesand high levels of gene flow among populations.ConclusionThere is a low genetic diversity and population structure in western Kenya. TEP1* R2 and TEP1*S1 were the most common alleles in both species which may have been maintained through generations in time, However, the TEP1*R2 allele was in low frequencies and may be used to estimatemalaria prevalence. Continued surveillance of the distribution of TEP1 is essential for monitoring the population dynamics of local vectors and their implications on malaria transmission and hence designing targeted vector interventions.

scholarly journals Molecular and morphological identification of suspected Plasmodium vivax vectors in Central and Eastern Sudan

2020 ◽  
Author(s):  
Omnia Fathelrhman Abdelwhab ◽  
Arwa Elaagip ◽  
Musab M. Albsheer ◽  
Ayman Ahmed ◽  
Giacomo Maria Paganotti ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Mosquito Species ◽  
Natural Infection ◽  
Sub Saharan Africa ◽  
Morphological Identification ◽  
Remarkable Change ◽  
Malaria Epidemiology ◽  
Central Sudan ◽  
First Time ◽  
Eastern Sudan

Abstract Background: In spite of the global effort to eliminate malaria, it remains the most significant vector-borne disease of humans. Plasmodium falciparum remains the dominant malaria parasite in Sub-Saharan Africa. However, P. vivax is becoming widely spread throughout Africa. The overuse of vector control methods has resulted in a remarkable change in the behaviour of mosquito that feeds on human as well as on vector composition. The aim of this study was to identify Anopheles mosquito species in vivax malaria endemic regions and to investigate their role in P. vivax malaria transmission.Methods: Mosquito samples were collected from Central Sudan (Khartoum and Sennar States) and Eastern Sudan (New Halfa) using Pyrethrum Spray Catch (PSC) and CDC light traps. Mosquitoes were identified using appropriate morphological identification keys and Anopheles gambiae complex were confirmed to species level using molecular analysis. A subset of blood-fed anopheline mosquitoes were dissectedto study the presence of natural infection of malaria parasites. In addition, the rest of the blood-fed samples were investigated for presence of infective sporozoites of P. vivax that detecting the P. vivax circumsporozoite protein (pvcsp) gene using nested-PCR.Results: A total of 644 adult anopheline blood-fed mosquitoes were collected from New Halfa (N = 214 mosquitoes), Khartoum (N = 132 mosquitoes), and Sennar (N = 298 mosquitoes). Morphological and molecular identification of the collected mosquitoes revealed the presence of An. arabiensis, An. funestus, and An. pharoensis. Out of 644 anophelines subjected to P. vivax sporozoite detection (N = 40, 6.2%) were positive for P. vivax.An. arabiensis 6.7% (39/583) and An. pharoensis 1.8% (1/56) were found positive for the parasite. While An. funestus was detected for the first time in New Halfa with low abundance (5/214 mosquitoes) and were found negative for the parasite.Conclusion: This study documented the presence of An. funestus for the first time in New Halfa, Eastern Sudan. However, An. arabiensis is the most abundant vector detected, together with An. pharoensis. This findings suggests change in malaria epidemiology. Further studies are needed to investigate their contribution in malaria transmission.

scholarly journals Molecular Identification of Native Wolbachia Pipientis in Anopheles Minimus in a Low-Malaria Transmission Area of Umphang Valley Along the Thailand-Myanmar Border

2020 ◽  
Author(s):  
Nongnat Tongkrajang ◽  
Pichet Ruenchit ◽  
Chatchai Tananchai ◽  
Theeraphap Chareonviriyaphap ◽  
Kasem Kulkeaw
Keyword(s):  
Malaria Transmission ◽  
Dna Sequences ◽  
Phylogenetic Trees ◽  
Mosquito Species ◽  
Malaria Vectors ◽  
Molecular Evidence ◽  
Wolbachia Pipientis ◽  
Close Relationship ◽  
Transmission Area ◽  
Low Malaria Transmission

Abstract BackgroundWolbachia, obligate intracellular bacteria, infect the majority of arthropods, including many mosquito species of medical importance. Some Wolbachia strains interfere with the development of Plasmodium parasites in female Anopheles, a major vector of malaria. The use of Wolbachia as a means to block malaria transmission is an emerging vector control strategy in highly endemic areas. Hence, identification of native Wolbachia strains in areas where malaria transmission is low may uncover a particular Wolbachia strain capable of Plasmodium interference. This study aims to identify native Wolbachia strains in female Anopheles spp. that are predominant in a low-malaria transmission area in mainland Southeast Asia.MethodsFollowing a two-year survey of malaria vectors in Umphang Valley of Tak Province, Thailand, DNA extracts of female An. minimus, An. peditaeniatus, An. maculatus, and An. dirus were subjected to amplification of the conserved region of the 16S rRNA-encoding gene. The DNA sequences of the amplicons were phylogenetically compared with those of known Wolbachia strains.ResultsAmong four Anopheles spp., amplification was detected in only the DNA samples from An. minimus. The DNA sequencing of amplicons revealed 100% similarity to Wolbachia pipientis, confirming the specificity of amplification. The phylogenetic trees indicate a close relationship with Wolbachia strains in subgroup B.ConclusionTo the best of our knowledge, the data presented herein provide the first molecular evidence of a Wolbachia strain in An. minimus, hereinafter named wAnmi, in a low-malaria transmission area in the Umphang Valley of western Thailand. Further biological characterization is required to examine its potential for malaria transmission control in the field.

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