Climate Change Influences on the Global Potential Distribution of the Mosquito Culex quinquefasciatus, Vector of West Nile Virus and Lymphatic Filariasis

Submitted by Adagilson Silva ([email protected]) on 2017-05-15T13:19:45Z No. of bitstreams: 1 27695107 2016 sam-cli.PDF: 5170317 bytes, checksum: 349e7da4c1f3736f565c0f4da8e46455 (MD5)Approved for entry into archive by Adagilson Silva ([email protected]) on 2017-05-15T13:25:36Z (GMT) No. of bitstreams: 1 27695107 2016 sam-cli.PDF: 5170317 bytes, checksum: 349e7da4c1f3736f565c0f4da8e46455 (MD5)Made available in DSpace on 2017-05-15T13:25:36Z (GMT). No. of bitstreams: 1 27695107 2016 sam-cli.PDF: 5170317 bytes, checksum: 349e7da4c1f3736f565c0f4da8e46455 (MD5) Previous issue date: 2016Ain Shams University. Faculty of Science. Entomology Department. Abbassia, Cairo, Egypt / University of Kansas. Biodiversity Institute. Lawrence, KS, United States of America.University of Khartoum. Faculty of Medical Laboratory Sciences. Department of Parasitology and Medical Entomology. Khartoum, Sudan.Ain Shams University. Faculty of Science. Entomology Department. Abbassia, Cairo, Egypt.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.University of Kansas. Biodiversity Institute. Lawrence, KS, United States of America.Ain Shams University. Faculty of Science. Entomology Department. Abbassia, Cairo, Egypt.Rapid emergence of most vector-borne diseases (VBDs) may be associated with range expansion of vector populations. Culex quinquefasciatus Say 1823 is a potential vector of West Nile virus, Saint Louis encephalitis virus, and lymphatic filariasis. We estimated the potential distribution of Cx. quinquefasciatus under both current and future climate conditions. The present potential distribution of Cx. quinquefasciatus showed high suitability across low-latitude parts of the world, reflecting the current distribution of the species. Suitable conditions were identified also in narrow zones of North Africa and Western Europe. Model transfers to future conditions showed a potential distribution similar to that under present-day conditions, although with higher suitability in southern Australia. Highest stability with changing climate was between 30°S and 30°N. The areas present high agreement among diverse climate models as regards distributional potential in the future, but differed in anticipating potential for distribution in North and Central Africa, southern Asia, central USA, and southeastern Europe. Highest disparity in model predictions across representative concentration pathways (RCPs) was in Saudi Arabia and Europe. The model predictions allow anticipation of changing distributional potential of the species in coming decades

Prevalence of malaria and dengue co-infections among febrile patients during dengue transmission season in Kassala, eastern Sudan.

BackgroundMalaria and dengue are common mosquito-borne diseases around the world that cause high mortality and morbidity. The number of cases of both diseases is currently rising in Sudan and is associated with climate and environmental changes. Limited information is available on malaria and dengue co-infections and the severity of the two diseases among febrile patients in eastern Sudan. Thus, this study aimed to estimate the prevalence of malaria and dengue co-infections among febrile patients in Kassala, eastern Sudan.Methodology/principal findingsA cross-sectional hospital-based study was conducted among febrile patients from September to December 2019. A total of 395 patients were enrolled after consenting to participate in the study. Demographic and clinical data were collected by structured questionnaires. Blood samples were provided to diagnose malaria infections using microscopy and polymerase chain reaction (PCR) and for serology diagnosis of dengue using enzyme-linked immune sorbent assay (ELISA) IgM. Multiple logistic regression analysis was used to assess the association between demographic information, clinical symptoms and malaria and dengue co-infections. Out of 395 febrile patients examined 158 (40%) were malaria positive and 67 (17%) were dengue positive. The prevalence of malaria and dengue co-infections was 6.6% (26/395). Results of multiple logistic regression indicated that elder patients (41-60 years) had less rate of co-infections (OR = 0.3, 95% CI 0.11 to 0.81, p-value = 0.018), while patients of co-infections were eight times more likely to have fatigue, and two times more likely to suffer from joint and muscle pain and this difference was statistically significant with (OR = 8.3, 95% CI: 1.89 to 37.22, p-value = 0.005) and (OR = 2.4, 95% CI 1.10 to 5.39, p-value = 0.027), respectively.Conclusions/significanceThis study confirmed the existence of malaria and dengue co-infections among febrile patients in Kassala, eastern Sudan for the first time. The severity of clinical symptoms of patients with malaria and dengue co-infections was observed, and the co-infections were found prevalent among young people

Impacts of Agricultural Practices on Insecticide Resistance in the Malaria Vector Anopheles arabiensis in Khartoum State, Sudan.

BACKGROUND Agricultural pesticides may play a profound role in selection of resistance in field populations of mosquito vectors. The objective of this study is to investigate possible links between agricultural pesticide use and development of resistance to insecticides by the major malaria vector Anopheles arabiensis in northern Sudan. METHODOLOGY/PRINCIPAL FINDINGS Entomological surveys were conducted during two agricultural seasons in six urban and peri-urban sites in Khartoum state. Agro-sociological data were collected from 240 farmers subjected to semi-structured questionnaires based on knowledge attitude and practice (KAP) surveys. Susceptibility status of An. arabiensis (n=6000) was assessed in all sites and during each season using WHO bioassay tests to DDT, deltamethrin, permethrin, Malathion and bendiocarb. KAP analysis revealed that pesticide application was common practice among both urban and peri-urban farmers, with organophosphates and carbamates most commonly used. Selection for resistance is likely to be greater in peri-urban sites where farmers apply pesticide more frequently and are less likely to dispose of surpluses correctly. Though variable among insecticides and seasons, broad-spectrum mortality was slightly, but significantly higher in urban than peri-urban sites and most marked for bendiocarb, to which susceptibility was lowest. Anopheles arabiensis from all sites showed evidence of resistance or suspected resistance, especially pyrethroids. However, low-moderate frequencies of the L1014F kdr allele in all sites, which was very strongly associated with DDT, permethrin and deltamethrin survivorship (OR=6.14-14.67) suggests that resistance could increase rapidly. CONCLUSIONS Ubiquitous multiple-resistance coupled with presence of a clear mechanism for DDT and pyrethroids (kdr L1014F) in populations of An. arabiensis from Khartoum-Sudan suggests careful insecticide management is essential to prolong efficacy. Our findings are consistent with agricultural insecticide use as a source of selection for resistance and argue for coordination between the integrated vector control program and the Ministry of Agriculture to permit successful implementation of rational resistance management strategies

Correction: Antimalarial drug resistance molecular markers of Plasmodium falciparum isolates from Sudan during 2015-2017.

[This corrects the article DOI: 10.1371/journal.pone.0235401.]

Antimalarial drug resistance molecular makers of Plasmodium falciparum isolates from Sudan during 2015-2017.

BackgroundCurrent malaria control and elimination strategies rely mainly on efficacious antimalarial drugs. However, drug resistance is a major threat facing malaria control programs. Determination of drug resistance molecular markers is useful in the monitoring and surveillance of malaria drug efficacy. This study aimed to determine the mutations and haplotypes frequencies of different genes linked with antimalarial drug resistance in certain areas in Sudan.MethodsA total of 226 dried blood spots (DBS) of microscopically diagnosed P. falciparum isolates were collected from Khartoum and three other areas in Sudan during 2015-2017. Plasmodium falciparum confirmation and multiplicity of infection was assessed using the Sanger's 101 SNPs-barcode and speciation was confirmed using regions of the parasite mitochondria. Molecular genotyping of drug resistance genes (Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, exonuclease, Pfk13, parasite genetic background (PGB) (Pfarps10, ferredoxin, Pfcrt, Pfmdr2)) was also performed. All genotypes were generated by selective regions amplicon sequencing of the parasite genome using the Illumina MiSeq platform at the Wellcome Sanger Institute, UK then genotypes were translated into drug resistance haplotypes and species determination.FindingsIn total 225 samples were confirmed to be P. falciparum. A higher proportion of multiplicity of infection was observed in Gezira (PConclusionsThere was high frequency of mutations in Pfcrt, Pfdhfr and Pfdhps in this study. These mutations are associated with chloroquine and sulfadoxine-pyrimethamine (SP) resistance. Many SNPs in Pfk13 not linked with delayed parasite clearance were observed. The exonuclease E415G mutation which is linked with piperaquine resistance was not reported

Current potential distribution of <i>Culex quinquefasciatus</i> based on present-day climatic conditions.

<p>Blue shaded areas were modeled as suitable; white areas were modeled as unsuitable.</p

Uncertainty estimates associated with <i>Culex quinquefasciatus</i> niches models under future conditions represented by four representative concentration pathways.

<p>Uncertainty estimates associated with <i>Culex quinquefasciatus</i> niches models under future conditions represented by four representative concentration pathways.</p

Predicted future potential distribution of <i>Culex quinquefasciatus</i> under four future representative concentration pathways of climate conditions.

<p>Red areas are modeled suitable conditions; white areas are unsuitable conditions.</p

Summary of 701 <i>Culex quinquefasciatus</i> occurrences available for model calibration.

<p>Summary of 701 <i>Culex quinquefasciatus</i> occurrences available for model calibration.</p

Summary of the modeled global distribution of <i>Culex quinquefasciatus</i> under both current and future climatic conditions to show the stability of predictions at present and into the future, and to illustrate differences among representative concentration pathways (RCPs).

<p>Dark blue represents model stability under both current and future conditions, dark red represents agreement among all climate models in anticipating potential distributional areas in the future, and light red indicates low agreement between diverse climate models as regards distributional potential in the future.</p