scholarly journals Secondary Malaria Vectors of Sub-Saharan Africa: Threat to Malaria Elimination on the Continent?

10.5772/65359 ◽  
2016 ◽  
Author(s):  
Yaw Asare Afrane ◽  
Mariangela Bonizzoni ◽  
Guiyun Yan
Keyword(s):  
Malaria Elimination ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Sub Saharan

scholarly journals Malaria in Eswatini, 2012-2019: A Case Study of the Elimination Effort.

2020 ◽  
Author(s):  
Theresia Estomih Nkya ◽  
Ulrike Fillinger ◽  
Makhoselive Dlamini ◽  
Onyango P. Sangoro ◽  
Rose Marubu ◽  
...  
Keyword(s):  
Malaria Elimination ◽  
Indoor Residual Spraying ◽  
Health Facilities ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Entomological Surveillance ◽  
Control Approach ◽  
Entry Points ◽  
Sub Saharan

Abstract Eswatini was the first country in sub-Saharan Africa to pass a National Malaria Elimination Policy in 2011 and later set a target for elimination by the year 2020. This case study aimed to review Eswatini’s progress towards malaria elimination by 2020. Coverage of indoor residual spraying (IRS) for vector control and data on malaria cases were provided by the National Malaria Programme (NMP) of Eswatini. The data included all cases treated for malaria in all health facilities. The data was analysed descriptively. Over the eight-year period, a total of 5,511 patients reported to the health facilities with malaria symptoms. Case investigation rate through the routine surveillance system increased from 50% in 2012 to 84% in 2019. Incidence per 1000 population at risk fluctuated between the years but in general increased from 0.70 in 2012 to 1.65 in 2019 with highest incidence of 3.19 reported in 2017. IRS data showed inconsistency in spraying over the eight-year period. Eswatini has fallen short of achieving malaria elimination by 2020. Malaria cases are still consistently reported, albeit at low rates, with occasional localised outbreaks. To achieve elimination, it is critical to optimise timely and well-targeted IRS and to consider rational expansion of tools for an integrated malaria control approach in Eswatini by including tools such as larval source management, long-lasting insecticidal nets (LLINs), screening of mosquito house entry points and chemoprophylaxis. The establishment of rigorous routine entomological surveillance should be among the priorities in order to determine the local malaria vectors’ ecology, potential species diversity and the role of secondary vectors and insecticide resistance.

scholarly journals Novel Wolbachia strains in Anopheles malaria vectors from Sub-Saharan Africa

2018 ◽  
Author(s):  
Claire L Jeffries ◽  
Gena G Lawrence ◽  
George Golovko ◽  
Mojca Kristan ◽  
James Orsborne ◽  
...  
Keyword(s):  
16S Rrna ◽  
Disease Control ◽  
Molecular Analysis ◽  
Malaria Prevalence ◽  
Sub Saharan Africa ◽  
16S Rrna Sequencing ◽  
Malaria Vectors ◽  
Rrna Sequencing ◽  
Dominant Member ◽  
Sub Saharan

AbstractAnopheles (An.) mosquitoes contain bacteria that can influence Plasmodium parasites. Wolbachia, a common insect endosymbiont, has historically been considered absent from Anopheles but has recently been found in An. gambiae populations. Here, we assessed a range of Anopheles species from five malaria-endemic countries for Wolbachia and Plasmodium infection. Strikingly, we found Wolbachia infections in An. coluzzii, An. gambiae s.s, An. arabiensis, An. moucheti and An. species ‘A’ increasing the number of Anopheles species known to be naturally infected by this endosymbiont. Molecular analysis suggests the presence of phylogenetically diverse novel strains, while qPCR and 16S rRNA sequencing indicates that Wolbachia is the dominant member of the microbiota in An. moucheti and An. species ‘A’. We found no evidence of Wolbachia/Asaia co-infections, and presence of these endosymbionts did not have significant effects on malaria prevalence. We discuss the importance of novel Wolbachia strains in Anopheles and potential implications for disease control.

scholarly journals Rising report of Plasmodium vivax in sub-Saharan Africa: Implications for malaria elimination agenda

2020 ◽  
Vol 10 ◽  
pp. e00596
Author(s):  
Mary Aigbiremo Oboh ◽  
Kolapo Muyiwa Oyebola ◽  
Emmanuel Taiwo Idowu ◽  
Aida Sadikh Badiane ◽  
Olubunmi Adetoro Otubanjo ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Malaria Elimination ◽  
Sub Saharan Africa ◽  
Sub Saharan

scholarly journals New Challenges in Malaria Elimination

2021 ◽  
Author(s):  
Susanta Kumar Ghosh ◽  
Chaitali Ghosh
Keyword(s):  
Malaria Elimination ◽  
New Technologies ◽  
Point Of Care ◽  
Artemisinin Resistance ◽  
Sub Saharan Africa ◽  
Chloroquine Resistance ◽  
World Health ◽  
Synthetic Pyrethroids ◽  
Sub Saharan ◽  
Health Organization

In recent years, efforts to eliminate malaria has gained a tremendous momentum, and many countries have achieved this goal — but it has faced many challenges. Recent COVID-19 pandemic has compounded the challenges due to cessation of many on-field operations. Accordingly, the World Health Organization (WHO) has advocated to all malaria-endemic countries to continue the malaria elimination operations following the renewed protocols. The recent reports of artemisinin resistance in Plasmodium falciparum followed by indication of chloroquine resistance in P. vivax, and reduced susceptibility of synthetic pyrethroids used in long lasting insecticide nets are some issues hindering the elimination efforts. Moreover, long distance night migration of vector mosquitoes in sub-Saharan Africa and invasion of Asian vector Anopheles stephensi in many countries including Africa and Southeast Asia have added to the problems. In addition, deletion of histidine rich protein 2 and 3 (Pfhrp2/3) genes in P. falciparum in many countries has opened new vistas to be addressed for point-of-care diagnosis of this parasite. It is needed to revisit the strategies adopted by those countries have made malaria elimination possible even in difficult situations. Strengthening surveillance and larval source management are the main strategies for successful elimination of malaria. New technologies like Aptamar, and artificial intelligence and machine learning would prove very useful in addressing many ongoing issues related to malaria elimination.

scholarly journals The relationship between house height and mosquito house entry: an experimental study in rural Gambia

2021 ◽  
Vol 18 (178) ◽  
pp. 20210256
Author(s):  
Majo Carrasco-Tenezaca ◽  
Musa Jawara ◽  
Mahamed Y. Abdi ◽  
John Bradley ◽  
Otis Sloan Brittain ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Experimental Study ◽  
Malaria Vector ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Light Traps ◽  
Experimental Huts ◽  
Sub Saharan ◽  
Malaria Mosquitoes ◽  
The Relationship

Most malaria infections in sub-Saharan Africa are acquired indoors, thus finding effective ways of preventing mosquito house entry should reduce transmission. Since most malaria mosquitoes fly less than 1 m from the ground, we tested whether raising buildings off the ground would prevent the entry of Anopheles gambiae , the principal African malaria vector, in rural Gambia. Nightly collections of mosquitoes were made using light traps from four inhabited experimental huts, each of which could be moved up or down. Mosquito house entry declined with increasing height, with a hut at 3 m reducing An. gambiae house entry by 84% when compared with huts on the ground. A propensity for malaria vectors to fly close to the ground and reduced levels of carbon dioxide, a major mosquito attractant, in elevated huts, may explain our findings. Raised buildings may help reduce malaria transmission in Africa.

scholarly journals Novel Wolbachia strains in Anopheles malaria vectors from Sub-Saharan Africa

2018 ◽  
Vol 3 ◽  
pp. 113 ◽  
Author(s):  
Claire L. Jeffries ◽  
Gena G. Lawrence ◽  
George Golovko ◽  
Mojca Kristan ◽  
James Orsborne ◽  
...  
Keyword(s):  
Control Strategies ◽  
Mosquito Species ◽  
Amplicon Sequencing ◽  
Pathogen Transmission ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Endosymbiotic Bacterium ◽  
Prevalence Rates ◽  
Republic Of The Congo ◽  
Sub Saharan

Background: Wolbachia, a common insect endosymbiotic bacterium that can influence pathogen transmission and manipulate host reproduction, has historically been considered absent from the Anopheles (An.) genera, but has recently been found in An. gambiae s.l. populations.  As there are numerous Anopheles species that have the capacity to transmit malaria, we analysed a range of species to determine Wolbachia prevalence rates, characterise novel Wolbachia strains and determine any correlation between the presence of Plasmodium, Wolbachia and the competing endosymbiotic bacterium Asaia. Methods: Anopheles adult mosquitoes were collected from five malaria-endemic countries: Guinea, Democratic Republic of the Congo (DRC), Ghana, Uganda and Madagascar, between 2013 and 2017.  Molecular analysis of samples was undertaken using quantitative PCR, Sanger sequencing, Wolbachia multilocus sequence typing (MLST) and high-throughput amplicon sequencing of the bacterial 16S rRNA gene.  Results: Novel Wolbachia strains were discovered in five species: An. coluzzii, An. gambiae s.s., An. arabiensis, An. moucheti and An. species ‘A’, increasing the number of Anopheles species known to be naturally infected. Variable prevalence rates in different locations were observed and novel strains were phylogenetically diverse, clustering with Wolbachia supergroup B strains.  We also provide evidence for resident strain variants within An. species ‘A’.  Wolbachia is the dominant member of the microbiome in An. moucheti and An. species ‘A’, but present at lower densities in An. coluzzii.  Interestingly, no evidence of Wolbachia/Asaia co-infections was seen and Asaia infection densities were also shown to be variable and location dependent.  Conclusions: The important discovery of novel Wolbachia strains in Anopheles provides greater insight into the prevalence of resident Wolbachia strains in diverse malaria vectors.  Novel Wolbachia strains (particularly high-density strains) are ideal candidate strains for transinfection to create stable infections in other Anopheles mosquito species, which could be used for population replacement or suppression control strategies.

scholarly journals Genomic and microscopic evidence of stable high density and maternally inherited Wolbachia infections in Anopheles mosquitoes

2020 ◽  
Author(s):  
Thomas Walker ◽  
Shannon Quek ◽  
Claire L. Jeffries ◽  
Janvier Bandibabone ◽  
Vishaal Dhokiya ◽  
...  
Keyword(s):  
Cytoplasmic Incompatibility ◽  
Pathogen Transmission ◽  
High Density ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Wild Populations ◽  
Independent Evidence ◽  
Anopheles Mosquitoes ◽  
Sub Saharan

AbstractWolbachia, a widespread bacterium that can reduce pathogen transmission in mosquitoes, has been detected within populations of Anopheles (An.) malaria vectors. In the An. gambiae complex, the primary vectors in Sub-Saharan Africa, Wolbachia strains are at low density and infection frequencies in wild populations. PCR-independent evidence is required to determine whether Wolbachia strains are true endosymbionts in Anopheles given most studies to date have used nested-PCR to identify strains. Here we report high-density strains found in geographically diverse populations of An. moucheti and An. demeilloni. Fluorescent in situ hybridization localized a heavy infection in the ovaries of An. moucheti and maternal transmission was observed. Genome sequencing of both strains obtained genome depths and coverages comparable to other known infections. Notably, homologs of cytoplasmic incompatibility factor (cif) genes were present indicating these strains possess the capacity to induce the phenotype cytoplasmic incompatibility which allows Wolbachia to spread through populations. The characteristics of these two strains suggest they are ideal candidates for Wolbachia biocontrol strategies in Anopheles.

scholarly journals Monitoring parasite diversity for malaria elimination in sub-Saharan Africa

Science ◽  
2014 ◽  
Vol 345 (6202) ◽  
pp. 1297-1298 ◽  
Author(s):  
A. Ghansah ◽  
L. Amenga-Etego ◽  
A. Amambua-Ngwa ◽  
B. Andagalu ◽  
T. Apinjoh ◽  
...  
Keyword(s):  
Malaria Elimination ◽  
Sub Saharan Africa ◽  
Parasite Diversity ◽  
Sub Saharan

scholarly journals Water Quality andAnopheles gambiaeLarval Tolerance to Pyrethroids in the Cities of Douala and Yaoundé (Cameroon)

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Billy Tene Fossog ◽  
Edmond Kopya ◽  
Cyrille Ndo ◽  
Benjamin Menze-Djantio ◽  
Carlo Costantini ◽  
...  
Keyword(s):  
Physicochemical Parameters ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Breeding Sites ◽  
The Poor ◽  
Insecticide Tolerance ◽  
Significant Difference ◽  
Kisumu Strain ◽  
Sub Saharan ◽  
Poor Management

The poor management of the urban environment in sub-Saharan Africa is affectingAnopheles gambiaesusceptibility to insecticides. A study was undertaken to assess the influence of breeding sites physicochemical parameters on malaria vectors population tolerance to insecticides. A total of 18, 262 larvae collected from 104 breeding sites were exposed to diagnostic concentrations of permethrin and deltamethrin. Larvae originating from cultivated sites were more tolerant than larvae from polluted or nonpolluted sites. No significant difference was observed between polluted and nonpolluted sites. Field larvae were 142 to 325 times and 6.08 to 9.57 times more tolerant to deltamethrin and permethrin, respectively, than larvae of theA. gambiaeKisumu strain used as control. A low but significant correlation was detected between physicochemical parameters and larval insecticide tolerance. Cultivated sites were negatively and significantly correlated to larval tolerance to both deltamethrin (r=−0.421;P<0.0001) and permethrin (r=−0.392;P<0.0001). Dissolved oxygen (r=+0.466;P<0.0001) and ammonia (r=−0.205;P=0.04) appeared significantly correlated to larval tolerance to deltamethrin. The data suggest a direct correlation between some characteristics from the breeding sites and larval tolerance to pyrethroids.

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