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.

BACKGROUND: Current 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. METHODS: A 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. FINDINGS: In total 225 samples were confirmed to be P. falciparum. A higher proportion of multiplicity of infection was observed in Gezira (P<0.001) based on the Sanger 101 SNPs -barcode. The overall frequency of mutant haplotype Pfcrt 72-76 CVIET was 71.8%. For Pfmdr1, N86Y was detected in 53.6%, Y184F was observed in 88.1% and D1246Y was detected in 1.5% of the samples. The most frequently observed haplotype was YFD 47.4%. For Pfdhfr (codons 51, 59,108,164), the ICNI haplotype was the most frequent (80.7%) while for Pfdhps (codons 436, 437, 540, 581, 613) the (SGEAA) was most frequent haplotype (41%). The Quadruple mutation (dhfr N51I, S108N + dhps A437G, K540E) was the highest frequent combined mutation (33.9%). In Pfkelch13 gene, 18 non-synonymous mutations were detected, 7 of them were detected in other African countries. The most frequent Pfk13 mutation was E433D detected in four samples. All of the Pfk13 mutant alleles have not been reported to belong to mutations associated with delayed parasite clearance in Southeast Asia. PGB mutations were detected only in Pfcrt N326S\I (46.3%) and Pfcrt I356T (8.2%). The exonuclease mutation was not detected. There was no significant variation in mutant haplotypes between study areas. CONCLUSIONS: There 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.

Socioeconomic impacts of elimination of onchocerciasis in Abu-Hamed focus, northern Sudan: lessons after elimination.

OBJECTIVES: Onchocerciasis is one of the most devastating neglected tropical diseases and it is mostly prevalent in Africa. The disease has important heavy social and economic burdens on the infected populations including low productivity, unemployment, social isolation, and stigma. A cross-sectional study was implemented using a well-established questionnaire to investigate the socio-economic impacts of Onchocerciasis elimination in Abu-Hamed, River Nile State, Sudan in 2015; 512 participants in ten affected communities were interviewed. RESULTS: Our findings revealed that these communities are recovering from the social and economic burden of the diseases. Ninety percent of the research participants reported general satisfaction about elimination of the disease in their community, 48.3% of them attended secondary school or university. Only 0.6% reported unemployment. Also, 25.3% and 24.7% of the participants were workers and farmers respectively. Except about the vector biting and nuisance, the majority of the respondents (90%) had no complain related to the disease after the elimination. Also, 90.5% of the participants reported either stable or increase in their work performance during the last 12 months. About 93.8% of the respondents were engaged in normal daily life activities and involved in happy events like marriage and giving birth during the last 12 months.

Identifying asymptomatic Leishmania infections in non-endemic villages in Gedaref state, Sudan.

OBJECTIVES: Infection with the causative agent of visceral leishmaniasis (VL) may be either symptomatic or asymptomatic. In this study we aimed at investigating the prevalence of asymptomatic infections of leishmania in non-endemic villages in Gedaref state, Sudan. A descriptive cross-sectional study conducted during September and October 2014. Blood samples were collected for serological and molecular analysis. Sticky-traps, knockdown spray and CDC-miniature light traps were used for the collection of sandflies. RESULTS: Ninety-Five participants were included; 52 from Abukishma, 15 Algadamblia Tirfa, 25 Abualnaja and 3 were from Algadamblia Aljabal. Females constituted 56 (58.9%) of the study participants while males were 39 (41.1%). The most frequent age group was > 40-years (54.7%). Balanites/Acacia trees were the most planted tree inside the houses; 78 (82.1%). Also, 85 (89.5%) of the participants breed animals inside the house. DAT test revealed 5 positive participants (5.2%). 4/5 DAT positive were past VL infection. PCR detected 35 (36.8%) positive participants. A total of 31/35 was considered asymptomatic infections based on PCR. Households planted Balanites/Acacia trees or breed domestic animals were found in high percentages with L. donovani PCR positive participants (60.1%, 91.4%). No statistically significant was found for VL associated risk factors and VL asymptomatic participants.

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

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.

Seasonal Variation in Biting Rates of Simulium damnosum sensu lato, Vector of Onchocerca volvulus, in Two Sudanese Foci.

BACKGROUND: The abundance of onchocerciasis vectors affects the epidemiology of disease in Sudan, therefore, studies of vector dynamics are crucial for onchocerciasis control/elimination programs. This study aims to compare the relative abundance, monthly biting-rates (MBR) and hourly-based distribution of onchocerciasis vectors in Abu-Hamed and Galabat foci. These seasonally-based factors can be used to structure vector control efforts to reduce fly-biting rates as a component of onchocerciasis elimination programs. METHODS: A cross-sectional study was conducted in four endemic villages in Abu-Hamed and Galabat foci during two non-consecutive years (2007-2008 and 2009-2010). Both adults and aquatic stages of the potential onchocerciasis vector Simulium damnosum sensu lato were collected following standard procedures during wet and dry seasons. Adult flies were collected using human landing capture for 5 days/month. The data was recorded on handheld data collection sheets to calculate the relative abundance, MBR, and hourly-based distribution associated with climatic factors. The data analysis was carried out using ANOVA and Spearman rank correlation tests. RESULTS: Data on vector surveillance revealed higher relative abundance of S. damnosum s.l. in Abu- Hamed (39,934 flies) than Galabat (8,202 flies). In Abu-Hamed, vector populations increased in January-April then declined in June-July until they disappeared in August-October. Highest black fly density and MBR were found in March 2007 (N = 9,444, MBR = 58,552.8 bites/person/month), and March 2010 (N = 2,603, MBR = 16,138.6 bites/person/month) while none of flies were collected in August-October (MBR = 0 bites/person/month). In Galabat, vectors increased in September-December, then decreased in February-June. The highest vector density and MBR were recorded in September 2007 (N = 1,138, MBR = 6,828 bites/person/month) and September 2010 (N = 1,163, MBR = 6,978 bites/person/month), whereas, none appeared in collection from April to June. There was a significant difference in mean monthly density of S. damnosum s.l. across the two foci in 2007-2008 (df = 3, F = 3.91, P = 0.011). Minimum temperature showed significant correlation with adult flies counts in four areas sampled; the adult counts were increased in Nady village (rs = 0.799) and were decreased in Kalasecal (rs = -0.676), Gumaiza (rs = -0.585), and Hilat Khateir (rs = -0.496). Maximum temperature showed positive correlation with black fly counts only in Galabat focus. Precipitation was significantly correlated with adult flies counts in Nady village, Abu-Hamed, but no significance was found in the rest of the sampled villages in both foci. Hourly-based distribution of black flies showed a unimodal pattern in Abu-Hamed with one peak (10:00-18:00), while a bimodal pattern with two peaks (07:00-10:00) and (14:00-18:00) was exhibited in Galabat. CONCLUSION: Transmission of onchocerciasis in both foci showed marked differences in seasonality, which may be attributed to ecology, microclimate and proximity of breeding sites to collection sites. The seasonal shifts between the two foci might be related to variations in climate zones. This information on black fly vector seasonality, ecology, distribution and biting activity has obvious implications in monitoring transmission levels to guide the national and regional onchocerciasis elimination programs in Sudan.

The impact of Merowe Dam on Simulium hamedense vector of onchocerciasis in Abu Hamed focus - Northern Sudan.

BACKGROUND: Abu Hamed, the northernmost onchocerciasis focus in the world, is located along the River Nile banks in the Nubian Desert. Hydroelectric dams can alter activity of black flies and may provide breeding sites for black fly. Merowe Dam, the largest hydropower project in Africa, was built west of Abu Hamed focus in 2009. The impact of the Dam on onchocerciasis and its black fly vectors in Abu Hamed focus was measured in this study. FINDINGS: Entomological surveys for aquatic stages and adult Simulium hamedense were conducted before and after the inception of Merowe Dam in 2007/2008 and 2010/2011. There was no black fly breeding or adult activity in the previously known breeding sites upstream of the Merowe Dam with the western most breeding site found in AlSarsaf village near the center of the focus. No adult or aquatic stages of black flies were found downstream of the Dam. CONCLUSIONS: The artificial lake of the Dam flooded all the breeding sites in the western region of the focus and no aquatic stages and/or adult black fly activity were established in the study area upstream of the Dam. The Dam seems to have positive impact on onchocerciasis and its black fly vectors in Abu Hamed focus. These outcomes of the Merowe Dam might have contributed to the recently declared interruption of onchocerciasis transmission in Abu Hamed focus. Continuous entomological surveys are needed to monitor presence of black fly vectors and its impact on the disease.

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.

Environmental pollution of lead in traffic air and blood of traffic policemen in Khartoum State, Sudan.

INTRODUCTION: A cross sectional study was conducted in Khartoum State. A total of 45 males' traffic policemen were divided into two groups according to exposure to car exhaust; n=30 taken as exposed group, n=15 taken as controls, who were not exposed to car exhaust. OBJECTIVES: The study was conducted to determine lead concentrations in traffic ambient air, to determine lead levels in blood of traffic policemen, and to evaluate the effect of exposure to car exhaust on traffic policemen during January 2009. METHODS: The level of lead in ambient air was determined in 14 locations which were taken randomly at the intersections and entrances to the bridges using personal sampler "Cassella, U.K". The blood samples of all policemen were analyzed by atomic absorption Spectrophotometer to determine lead levels. A questionnaire was designed to assess the adverse health effects on the traffic policemen. RESULTS: The degree of environmental lead pollution in traffic ambient air was found to be 0.1937 +/- 0.1768 mg/m3 with range between 0.000-0.5166 mg/m3. In seven locations out of fourteen locations lead concentrations were 0.1940 and 0.5166 above the permissible level of 0.15 mg/m3 permitted internationally. Blood lead levels on traffic policemen (exposed and control groups) were found to be 2.4691 +/- 1.4065 microg/100 ml and 0.3944 +/- 1.2471 microg/100 ml respectively and there is no significant differences between the two groups where using SPSS program. A questionnaire findings were: average age mean of 35.9 +/- 7.7 years, 47.48% worked for periods of more than 20 years, 74.19% did not work before joining the traffic police, 51.6% of them recognized traffic air pollution as a problem of high level, 45.2% of them estimated it as medium, and 3.2% as low. As habits 38.71% were smokers, and for health complaints, 61.29% have various complaints of headache, fatigue, abdominal, hypertension and anemia. All these symptoms have a close relationship with lead poisoning. CONCLUSION: When we compared the results of age groups and work duration with lead levels of blood samples the results was not significant.

Environmental pollution of lead in traffic air and blood of traffic policemen in Khartoum State, Sudan.

INTRODUCTION: A cross sectional study was conducted in Khartoum State. A total of 45 males' traffic policemen were divided into two groups according to exposure to car exhaust; n = 30 taken as exposed group, n = 15 taken as controls, who were not exposed to car exhaust. OBJECTIVES: The study was conducted to determine lead concentrations in traffic ambient air, to determine lead levels in blood of traffic policemen, and to evaluate the effect of exposure to car exhaust on traffic policemen during January 2009. METHODS: The level of lead in ambient air was determined in 14 locations which were taken randomly at the intersections and entrances to the bridges using personal sampler "Cassella, U.K". The blood samples of all policemen were analyzed by atomic absorption Spectrophotometer to determine lead levels. A questionnaire was designed to assess the adverse health effects on the traffic policemen. RESULTS: The degree of environmental lead pollution in traffic ambient air was found to be 0.1937 +/- 0.1768 mg/m3 with range between 0.000-0.5166 mg/m3. In seven locations out of fourteen locations lead concentrations were 0.1940 and 0.5166 above the permissible level of 0.15 mg/m3 permitted internationally. Blood lead levels on traffic policemen (exposed and control groups) were found to be 2.4691 +/- 1.4065 microg/100 ml and 0.3944 +/- 1.2471 microg/100 ml respectively and there is no significant differences between the two groups where using SPSS program. A questionnaire findings were: average age mean of 35.9 +/- 7.7 years, 47.48% worked for periods of more than 20 years, 74.19% did not work before joining the traffic police, 51.6% of them recognized traffic air pollution as a problem of high level, 45.2% of them estimated it as medium, and 3.2% as low. As habits 38.71% were smokers, and for health complaints, 61.29% have various complaints of headache, fatigue, abdominal, hypertension and anemia. All these symptoms have a close relationship with lead poisoning. CONCLUSION: When we compared the results of age groups and work duration with lead levels of blood samples the results was not significant.