Last data update: Dec 02, 2024. (Total: 48272 publications since 2009)
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Query Trace: Yohannes F[original query] |
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Incidence and predictors of attrition from HIV treatment among adults living with HIV in high-caseload facilities following implementation of universal test and treat strategy in Ethiopia: A prospective cohort study
Bekele A , Ahmed I , Tefera F , Yimam JA , Woldeselassie FT , Abera G , Ahmed J , Mekonnen A , Haile A , Yohannes F , Getachew M , Abdella S , Shah M . HIV Med 2024 BACKGROUND: The introduction of universal test and treat (UTT) strategy has demonstrated a reduction in attrition in some low-resource settings. UTT was introduced in Ethiopia in 2016. However, there is a paucity of information regarding the magnitude and predictors of attrition from HIV treatment in Ethiopia. This study aims to assess the incidence and predictors of attrition from HIV treatment among adults living with HIV (PLHIV) in high-caseload facilities following the implementation of universal test and treat strategy in Ethiopia from March 2019 to June 2020. METHODS: A prospective cohort of individuals in HIV care from 39 high-caseload facilities in Oromia, Amhara, Tigray, Addis Ababa and Dire Dawa regions of Ethiopia was conducted for 12 months. Participants were adults aged 15 year and older who were first testers recruited for 3 months from March to June 2019. Subsequent follow-up was for 12 months, with data collected on sociodemographic and clinical conditions at baseline, 6 and 12 months and attrition at 6 and 12 months. We defined attrition as discontinuation from follow-up care due to loss to follow-up, dropout or death. Data were collected using Open Data Kit at field level and aggregated centrally. Kaplan-Meier survival analysis was employed to assess survival probability to the time of attrition from treatment. The Cox proportional hazards regression model was used to measure association of baseline predictor variables with the proportion of antiretroviral therapy (ART) patients retained in ART during the follow up period. RESULTS: The overall incidence rate for attrition from HIV treatment among the study participants during 12 months of follow-up was 5.02 cases per 1000 person-weeks [95% confidence interval (CI): 4.44-5.68 per 1000 person-weeks]. Study participants from health facilities in Oromia and Addis Ababa/Dire Dawa had 68% and 51% higher risk of attrition from HIV treatment compared with participants from the Amhara region, respectively [adjusted hazard ratio (AHR) = 1.68, 95% CI: 1.22-2.32 and AHR = 1.51, 95% CI: 1.05-2.17, respectively]. Participants who did not have a child had a 44% higher risk of attrition compared with those who had a child (AHR = 1.44, 95% CI: 1.12-1.85). Individuals who did not own mobile phone had a 37% higher risk of attrition than those who owned a mobile phone (AHR = 1.37, 95% CI: 1.02-1.83). Ambulatory/bedridden functional status at the time of diagnosis had a 44% higher risk of attrition compared with participants with a working functional status (AHR = 1.44, 95% CI: 1.08-1.92) at any time during the follow-up period. CONCLUSION: The overall incidence of attrition among people living with HIV enrolled into HIV treatment was not as high as what was reported by other studies. Independent predictors of attrition were administrative regions in Ethiopia where health facilities are located, not having a child, not owning a mobile phone and being ambulatory/bedridden functional status at the time of diagnosis. Concerted efforts should be taken to reduce the magnitude of attrition from HIV treatment and address its drivers. |
Correction: Laboratory-based efficacy evaluation of Bacillus thuringiensis var. israelensis and temephos larvicides against larvae of Anopheles stephensi in Ethiopia
Teshome A , Erko B , Golassa L , Yohannes G , Irish SR , Zohdy S , Dugassa S . Malar J 2023 22 (1) 312 Following publication of the original article [1], the authors flagged the following errors: in the subsection ‘Efficacy of Bacillus thuringiensis var. israelensis and temephos against An. stephensi larvae’, they had referred to VectoBac WDG instead of FourStar®Briquets; in the Discussion and the Conclusion, they had referred to ‘Bti VectoBac’ where it should just say ‘Bti’. The authors thank you for reading and apologize for any inconvenience caused. |
Resistance of Anopheles stephensi to selected insecticides used for indoor residual spraying and long-lasting insecticidal nets in Ethiopia
Teshome A , Erko B , Golassa L , Yohannes G , Irish SR , Zohdy S , Yoshimizu M , Dugassa S . Malar J 2023 22 (1) 218 BACKGROUND: Malaria, transmitted by the bite of infective female Anopheles mosquitoes, remains a global public health problem. The presence of invasive Anopheles stephensi, capable of transmitting Plasmodium vivax and Plasmodium falciparum, was first reported in Ethiopia in 2016. The ecology of this mosquito species differs from that of Anopheles arabiensis, the primary malaria vector in Ethiopia. This study aimed to evaluate the efficacy of selected insecticides, which are used in indoor residual spraying (IRS) and selected long-lasting insecticidal nets (LLINs) for malaria vector control against adult An. stephensi. METHODS: Anopheles stephensi mosquitoes were collected as larvae and pupae from Awash Subah Kilo Town and Haro Adi village, Ethiopia. Adult female An. stephensi, reared from larvae and pupae collected from the field, aged 3-5 days were exposed to impregnated papers of IRS insecticides (propoxur 0.1%, bendiocarb 0.1%, pirimiphos-methyl 0.25%), and insecticides used in LLINs (alpha-cypermethrin 0.05%, deltamethrin 0.05% and permethrin 0.75%), using diagnostic doses and WHO test tubes in a bio-secure insectary at Aklilu Lemma Institute of Pathobiology, Addis Ababa University. For each test and control tube, batches of 25 female An. stephensi were used to test each insecticide used in IRS. Additionally, cone bioassay tests were conducted to expose An. stephensi from the reared population to four brands of LLINs, MAGNet™ (alpha-cypermethrin), PermaNet(®) 2.0 (deltamethrin), DuraNet(©) (alpha-cypermethrin) and SafeNet(®) (alpha-cypermethrin). A batch of ten sugar-fed female mosquitoes aged 2-5 days was exposed to samples taken from five positions/sides of a net. The data from all replicates were pooled and descriptive statistics were used to describe features of the data. RESULTS: All An. stephensi collected from Awash Subah Kilo Town and Haro Adi village (around Metehara) were resistant to all tested insecticides used in both IRS and LLINs. Of the tested LLINs, only MAGNet™ (alpha-cypermethrin active ingredient) caused 100% knockdown and mortality to An. stephensi at 60 min and 24 h post exposure, while all other net brands caused mortality below the WHO cut-off points (< 90%). All these nets, except SafeNet(®), were collected during LLIN distribution for community members through the National Malaria Programme, in December 2020. CONCLUSIONS: Anopheles stephensi is resistant to all tested insecticides used in IRS and in the tested LLIN brands did not cause mosquito mortality as expected, except MAGNet. This suggests that control of this invasive vector using existing adult malaria vector control methods will likely be inadequate and that alternative strategies may be necessary. |
Geographical distribution of Anopheles stephensi in eastern Ethiopia (preprint)
Balkew M , Mumba P , Dengela D , Yohannes G , Getachew D , Yared S , Chibsa S , Murphy M , George K , Lopez K , Janies D , Choi SH , Spear J , Irish SR , Carter TE . bioRxiv 2019 802587 Background The recent detection of the South Asian malaria vector An. stephensi in Ethiopia and other regions in the Horn of Africa has raised concerns about its potential impact on malaria transmission. We report here findings of survey for this species in eastern Ethiopia using both morphological and molecular methods for species identification.Methods Adult and larval/pupal collections were conducted at ten sites in eastern Ethiopia and Anopheles specimens’ species were determined using standard morphological keys and genetic analysis.Results In total, 2,231 morphologically identified An. stephensi were collected. A molecular approach incorporating both PCR endpoint assay and sequencing of portions of the internal transcribed spacer 2 (ITS2) and cytochrome oxidase I (COI) loci confirmed the identity of the An. stephensi in most cases (119/124 of the morphologically identified An. stephensi confirmed molecularly). Additionally, we observed Aedes aegypti larvae and pupae at many of the An. stephensi larval habitats.Conclusions Our findings show that An. stephensi is widely distributed in eastern Ethiopia and highlight the need for further surveillance in the southern, western and northern parts of the country and throughout the Horn of Africa. |
Preventing HIV among adolescent boys and young men through PEPFAR-supported voluntary medical male circumcision in 15 Sub-Saharan African Countries, 2018-2021
Peck ME , Ong K , Lucas T , Thomas AG , Wandira R , Ntwaaga B , Mkhontfo M , Zegeye T , Yohannes F , Mulatu D , Gultie T , Juma AW , Odoyo-June E , Maida A , Msungama W , Canda M , Mutandi G , Zemburuka BLT , Kankindi I , Vranken P , Maphothi N , Loykissoonlal D , Bunga S , Grund JM , Kazaura KJ , Kabuye G , Chituwo O , Muyunda B , Kamboyi R , Lingenda G , Mandisarisa J , Peterson A , Malaba R , Xaba S , Moyo T , Toledo C . AIDS Educ Prev 2023 35 67-81 Voluntary medical male circumcision (VMMC) is an HIV prevention intervention that has predominantly targeted adolescent and young men, aged 10-24 years. In 2020, the age eligibility for VMMC shifted from 10 to 15 years of age. This report describes the VMMC client age distribution from 2018 to 2021, at the site, national, and regional levels, among 15 countries in southern and eastern Africa. Overall, in 2018 and 2019, the highest proportion of VMMCs were performed among 10-14-year-olds (45.6% and 41.2%, respectively). In 2020 and 2021, the 15-19-year age group accounted for the highest proportion (37.2% and 50.4%, respectively) of VMMCs performed across all age groups. Similarly, in 2021 at the site level, 68.1% of VMMC sites conducted the majority of circumcisions among men aged 15-24 years. This analysis highlights that adolescent boys and young men are the primary recipients of VMMC receiving an important lifetime reduction in HIV risk. |
Laboratory-based efficacy evaluation of Bacillus thuringiensis var. israelensis and temephos larvicides against larvae of Anopheles stephensi in Ethiopia
Teshome A , Erko B , Golassa L , Yohannes G , Irish SR , Zohdy S , Dugassa S . Malar J 2023 22 (1) 48 BACKGROUND: Malaria, transmitted by the bite of infective female Anopheles mosquitoes, remains a global public health problem. The presence of an invasive Anopheles stephensi, capable of transmitting Plasmodium vivax and Plasmodium falciparum parasites was first reported in Ethiopia in 2016. The ecology of An. stephensi is different from that of Anopheles arabiensis, the primary Ethiopian malaria vector, and this suggests that alternative control strategies may be necessary. Larviciding may be an effective alternative strategy, but there is limited information on the susceptibility of Ethiopian An. stephensi to common larvicides. This study aimed to evaluate the efficacy of temephos and Bacillus thuringiensis var. israelensis (Bti) larvicides against larvae of invasive An. stephensi. METHODS: The diagnostic doses of two larvicides, temephos (0.25 ml/l) and Bti (0.05 mg/l) were tested in the laboratory against the immature stages (late third to early fourth stages larvae) of An. stephensi collected from the field and reared in a bio-secure insectary. Larvae were collected from two sites (Haro Adi and Awash Subuh Kilo). For each site, three hundred larvae were tested against each insecticide (as well as an untreated control), in batches of 25. The data from all replicates were pooled and descriptive statistics prepared. RESULTS: The mortality of larvae exposed to temephos was 100% for both sites. Mortality to Bti was 99.7% at Awash and 100% at Haro Adi site. CONCLUSIONS: Larvae of An. stephensi are susceptible to temephos and Bti larvicides suggesting that larviciding with these insecticides through vector control programmes may be effective against An. stephensi in these localities. |
Detection and population genetic analysis of kdr L1014F variant in eastern Ethiopian Anopheles stephensi.
Samake JN , Yared S , Getachew D , Mumba P , Dengela D , Yohannes G , Chibsa S , Choi SH , Spear J , Irish SR , Zohdy S , Balkew M , Carter TE . Infect Genet Evol 2022 99 105235 Anopheles stephensi is a malaria vector that has been recently introduced into East Africa, where it threatens to increase malaria disease burden. The use of insecticides, especially pyrethroids, is still one of the primary malaria vector control strategies worldwide. The knockdown resistance (kdr) mutation in the IIS6 transmembrane segment of the voltage-gated sodium channel (vgsc) is one of the main molecular mechanisms of pyrethroid resistance in Anopheles. Extensive pyrethroid resistance in An. stephensi has been previously reported in Ethiopia. Thus, it is important to determine whether or not the kdr mutation is present in An. stephensi populations in Ethiopia to inform vector control strategies. In the present study, the kdr locus was analyzed in An. stephensi collected from ten urban sites (Awash Sebat Kilo, Bati, Dire Dawa, Degehabur, Erer Gota, Godey, Gewane, Jigjiga, Semera, and Kebridehar) situated in Somali, Afar, and Amhara regions, and Dire Dawa Administrative City, to evaluate the frequency and evolution of kdr mutations and the association of the mutation with permethrin resistance phenotypes. Permethrin is one of the pyrethroid insecticides used for vector control in eastern Ethiopia. DNA extractions were performed on adult mosquitoes from CDC light trap collections and those raised from larval and pupal collections. PCR and targeted sequencing were used to analyze the IIS6 transmembrane segment of the vgsc gene. Of 159 An. stephensi specimens analyzed from the population survey, nine (5.7%) carried the kdr mutation (L1014F). An. stephensi with kdr mutations were only observed from Bati, Degehabur, Dire Dawa, Gewane, and Semera. We further randomly selected twenty resistant and twenty susceptible An. stephensi mosquitoes from Dire Dawa post-exposure to permethrin and investigated the role of kdr in pyrethroid resistance by comparing the vgsc gene in the two populations. We found no kdr mutations in the permethrin-resistant mosquitoes. Population genetic analysis of the sequences, including neighboring introns, revealed limited evidence of non-neutral evolution (e.g., selection) at this locus. The low kdr mutation frequency detected and the lack of kdr mutation in the permethrin-resistant mosquitoes suggest the existence of other molecular mechanisms of pyrethroid resistance in eastern Ethiopian An. stephensi. |
Genetic diversity of Anopheles stephensi in Ethiopia provides insight into patterns of spread.
Carter TE , Yared S , Getachew D , Spear J , Choi SH , Samake JN , Mumba P , Dengela D , Yohannes G , Chibsa S , Murphy M , Dissanayake G , Flately C , Lopez K , Janies D , Zohdy S , Irish SR , Balkew M . Parasit Vectors 2021 14 (1) 602 BACKGROUND: The recent detection of the South Asian malaria vector Anopheles stephensi in the Horn of Africa (HOA) raises concerns about the impact of this mosquito on malaria transmission in the region. Analysis of An. stephensi genetic diversity and population structure can provide insight into the history of the mosquito in the HOA to improve predictions of future spread. We investigated the genetic diversity of An. stephensi in eastern Ethiopia, where detection suggests a range expansion into this region, in order to understand the history of this invasive population. METHODS: We sequenced the cytochrome oxidase subunit I (COI) and cytochrome B gene (CytB) in 187 An. stephensi collected from 10 sites in Ethiopia in 2018. Population genetic, phylogenetic, and minimum spanning network analyses were conducted for Ethiopian sequences. Molecular identification of blood meal sources was also performed using universal vertebrate CytB sequencing. RESULTS: Six An. stephensi COI-CytB haplotypes were observed, with the highest number of haplotypes in the northeastern sites (Semera, Bati, and Gewana towns) relative to the southeastern sites (Kebridehar, Godey, and Degehabur) in eastern Ethiopia. We observed population differentiation, with the highest differentiation between the northeastern sites compared to central sites (Erer Gota, Dire Dawa, and Awash Sebat Kilo) and the southeastern sites. Phylogenetic and network analysis revealed that the HOA An. stephensi are more genetically similar to An. stephensi from southern Asia than from the Arabian Peninsula. Finally, molecular blood meal analysis revealed evidence of feeding on cows, goats, dogs, and humans, as well as evidence of multiple (mixed) blood meals. CONCLUSION: We show that An. stephensi is genetically diverse in Ethiopia and with evidence of geographical structure. Variation in the level of diversity supports the hypothesis for a more recent introduction of An. stephensi into southeastern Ethiopia relative to the northeastern region. We also find evidence that supports the hypothesis that HOA An. stephensi populations originate from South Asia rather than the Arabian Peninsula. The evidence of both zoophagic and anthropophagic feeding support the need for additional investigation into the potential for livestock movement to play a role in vector spread in this region. |
An update on the distribution, bionomics, and insecticide susceptibility of Anopheles stephensi in Ethiopia, 2018-2020
Balkew M , Mumba P , Yohannes G , Abiy E , Getachew D , Yared S , Worku A , Gebresilassie A , Tadesse FG , Gadisa E , Esayas E , Ashine T , Yewhalaw D , Chibsa S , Teka H , Murphy M , Yoshimizu M , Dengela D , Zohdy S , Irish S . Malar J 2021 20 (1) 263 BACKGROUND: Anopheles stephensi, an invasive malaria vector, was first detected in Africa nearly 10 years ago. After the initial finding in Djibouti, it has subsequently been found in Ethiopia, Sudan and Somalia. To better inform policies and vector control decisions, it is important to understand the distribution, bionomics, insecticide susceptibility, and transmission potential of An. stephensi. These aspects were studied as part of routine entomological monitoring in Ethiopia between 2018 and 2020. METHODS: Adult mosquitoes were collected using human landing collections, pyrethrum spray catches, CDC light traps, animal-baited tent traps, resting boxes, and manual aspiration from animal shelters. Larvae were collected using hand-held dippers. The source of blood in blood-fed mosquitoes and the presence of sporozoites was assessed through enzyme-linked immunosorbent assays (ELISA). Insecticide susceptibility was assessed for pyrethroids, organophosphates and carbamates. RESULTS: Adult An. stephensi were collected with aspiration, black resting boxes, and animal-baited traps collecting the highest numbers of mosquitoes. Although sampling efforts were geographically widespread, An. stephensi larvae were collected in urban and rural sites in eastern Ethiopia, but An. stephensi larvae were not found in western Ethiopian sites. Blood-meal analysis revealed a high proportion of blood meals that were taken from goats, and only a small proportion from humans. Plasmodium vivax was detected in wild-collected An. stephensi. High levels of insecticide resistance were detected to pyrethroids, carbamates and organophosphates. Pre-exposure to piperonyl butoxide increased susceptibility to pyrethroids. Larvae were found to be susceptible to temephos. CONCLUSIONS: Understanding the bionomics, insecticide susceptibility and distribution of An. stephensi will improve the quality of a national response in Ethiopia and provide additional information on populations of this invasive species in Africa. Further work is needed to understand the role that An. stephensi will have in Plasmodium transmission and malaria case incidence. While additional data are being collected, national programmes can use the available data to formulate and operationalize national strategies against the threat of An. stephensi. |
Anopheles stephensi Mosquitoes as Vectors of Plasmodium vivax and falciparum, Horn of Africa, 2019
Tadesse FG , Ashine T , Teka H , Esayas E , Messenger LA , Chali W , Meerstein-Kessel L , Walker T , Wolde Behaksra S , Lanke K , Heutink R , Jeffries CL , Mekonnen DA , Hailemeskel E , Tebeje SK , Tafesse T , Gashaw A , Tsegaye T , Emiru T , Simon K , Bogale EA , Yohannes G , Kedir S , Shumie G , Sabir SA , Mumba P , Dengela D , Kolaczinski JH , Wilson A , Churcher TS , Chibsa S , Murphy M , Balkew M , Irish S , Drakeley C , Gadisa E , Bousema T . Emerg Infect Dis 2021 27 (2) 603-607 Anopheles stephensi mosquitoes, efficient vectors in parts of Asia and Africa, were found in 75.3% of water sources surveyed and contributed to 80.9% of wild-caught Anopheles mosquitoes in Awash Sebat Kilo, Ethiopia. High susceptibility of these mosquitoes to Plasmodium falciparum and vivax infection presents a challenge for malaria control in the Horn of Africa. |
Malaria in migrant agricultural workers in western Ethiopia: entomological assessment of malaria transmission risk
Dugassa S , Murphy M , Chibsa S , Tadesse Y , Yohannes G , Lorenz LM , Solomon H , Yewhalaw D , Irish SR . Malar J 2021 20 (1) 95 BACKGROUND: Ethiopia has made great strides in malaria control over the last two decades. However, this progress has not been uniform and one concern has been reported high rates of malaria transmission in large agricultural development areas in western Ethiopia. Improved vector control is one way this transmission might be addressed, but little is known about malaria vectors in this part of the country. METHODS: To better understand the vector species involved in malaria transmission and their behaviour, human landing collections were conducted in Dangur woreda, Benishangul-Gumuz, between July and December 2017. This period encompasses the months with the highest rain and the peak mosquito population. Mosquitoes were identified to species and tested for the presence of Plasmodium sporozoites. RESULTS: The predominant species of the Anopheles collected was Anopheles arabiensis (1,733; i.e. 61.3 % of the entire Anopheles), which was also the only species identified with sporozoites (Plasmodium falciparum and Plasmodium vivax). Anopheles arabiensis was collected as early in the evening as 18:00 h-19:00 h, and host-seeking continued until 5:00 h-6:00 h. Nearly equal numbers were collected indoors and outdoors. The calculated entomological inoculation rate for An. arabiensis for the study period was 1.41 infectious bites per month. More An. arabiensis were collected inside and outside worker's shelters than in fields where workers were working at night. CONCLUSIONS: Anopheles arabiensis is likely to be the primary vector of malaria in the agricultural development areas studied. High rates of human biting took place inside and outdoor near workers' residential housing. Improved and targeted vector control in this area might considerably reduce malaria transmission. |
Geographical distribution of Anopheles stephensi in eastern Ethiopia.
Balkew M , Mumba P , Dengela D , Yohannes G , Getachew D , Yared S , Chibsa S , Murphy M , George K , Lopez K , Janies D , Choi SH , Spear J , Irish SR , Carter TE . Parasit Vectors 2020 13 (1) 35 BACKGROUND: The recent detection of the South Asian malaria vector Anopheles stephensi in Ethiopia and other regions in the Horn of Africa has raised concerns about its potential impact on malaria transmission. We report here the findings of a survey for this species in eastern Ethiopia using both morphological and molecular methods for species identification. METHODS: Adult and larval/pupal collections were conducted at ten sites in eastern Ethiopia and Anopheles specimens were identified using standard morphological keys and genetic analysis. RESULTS: In total, 2231 morphologically identified An. stephensi were collected. A molecular approach incorporating both PCR endpoint assay and sequencing of portions of the internal transcribed spacer 2 (ITS2) and cytochrome c oxidase subunit 1 (cox1) loci confirmed the identity of the An. stephensi in most cases (119/124 of the morphologically identified An. stephensi confirmed molecularly). Additionally, we observed Aedes aegypti larvae and pupae at many of the An. stephensi larval habitats. CONCLUSIONS: Our findings show that An. stephensi is widely distributed in eastern Ethiopia and highlight the need for further surveillance in the southern, western and northern parts of the country and throughout the Horn of Africa. |
Insecticide resistance in Anopheles arabiensis from Ethiopia (2012-2016): a nationwide study for insecticide resistance monitoring
Messenger LA , Shililu J , Irish SR , Anshebo GY , Tesfaye AG , Ye-Ebiyo Y , Chibsa S , Dengela D , Dissanayake G , Kebede E , Zemene E , Asale A , Yohannes M , Taffese HS , George K , Fornadel C , Seyoum A , Wirtz RA , Yewhalaw D . Malar J 2017 16 (1) 469 BACKGROUND: Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) remain the cornerstones of malaria vector control. However, the development of insecticide resistance and its implications for operational failure of preventative strategies are of concern. The aim of this study was to characterize insecticide resistance among Anopheles arabiensis populations in Ethiopia and describe temporal and spatial patterns of resistance between 2012 and 2016. METHODS: Between 2012 and 2016, resistance status of An. arabiensis was assessed annually during the long rainy seasons in study sites from seven of the nine regions in Ethiopia. Insecticide resistance levels were measured with WHO susceptibility tests and CDC bottle bioassays using insecticides from four chemical classes (organochlorines, pyrethroids, organophosphates and carbamates), with minor variations in insecticides tested and assays conducted between years. In selected sites, CDC synergist assays were performed by pre-exposing mosquitoes to piperonyl butoxide (PBO). In 2015 and 2016, mosquitoes from DDT and deltamethrin bioassays were randomly selected, identified to species-level and screened for knockdown resistance (kdr) by PCR. RESULTS: Intense resistance to DDT and pyrethroids was pervasive across Ethiopia, consistent with historic use of DDT for IRS and concomitant increases in insecticide-treated net coverage over the last 15 years. Longitudinal resistance trends to malathion, bendiocarb, propoxur and pirimiphos-methyl corresponded to shifts in the national insecticide policy. By 2016, resistance to the latter two insecticides had emerged, with the potential to jeopardize future long-term effectiveness of vector control activities in these areas. Between 2015 and 2016, the West African (L1014F) kdr allele was detected in 74.1% (n = 686/926) of specimens, with frequencies ranging from 31 to 100% and 33 to 100% in survivors from DDT and deltamethrin bioassays, respectively. Restoration of mosquito susceptibility, following pre-exposure to PBO, along with a lack of association between kdr allele frequency and An. arabiensis mortality rate, both indicate metabolic and target-site mutation mechanisms are contributing to insecticide resistance. CONCLUSIONS: Data generated by this study will strengthen the National Malaria Control Programme's insecticide resistance management strategy to safeguard continued efficacy of IRS and other malaria control methods in Ethiopia. |
A Phylogeny-Based Global Nomenclature System and Automated Annotation Tool for H1 Hemagglutinin Genes from Swine Influenza A Viruses.
Anderson TK , Macken CA , Lewis NS , Scheuermann RH , Van Reeth K , Brown IH , Swenson SL , Simon G , Saito T , Berhane Y , Ciacci-Zanella J , Pereda A , Davis CT , Donis RO , Webby RJ , Vincent AL . mSphere 2016 1 (6) The H1 subtype of influenza A viruses (IAVs) has been circulating in swine since the 1918 human influenza pandemic. Over time, and aided by further introductions from nonswine hosts, swine H1 viruses have diversified into three genetic lineages. Due to limited global data, these H1 lineages were named based on colloquial context, leading to a proliferation of inconsistent regional naming conventions. In this study, we propose rigorous phylogenetic criteria to establish a globally consistent nomenclature of swine H1 virus hemagglutinin (HA) evolution. These criteria applied to a data set of 7,070 H1 HA sequences led to 28 distinct clades as the basis for the nomenclature. We developed and implemented a web-accessible annotation tool that can assign these biologically informative categories to new sequence data. The annotation tool assigned the combined data set of 7,070 H1 sequences to the correct clade more than 99% of the time. Our analyses indicated that 87% of the swine H1 viruses from 2010 to the present had HAs that belonged to 7 contemporary cocirculating clades. Our nomenclature and web-accessible classification tool provide an accurate method for researchers, diagnosticians, and health officials to assign clade designations to HA sequences. The tool can be updated readily to track evolving nomenclature as new clades emerge, ensuring continued relevance. A common global nomenclature facilitates comparisons of IAVs infecting humans and pigs, within and between regions, and can provide insight into the diversity of swine H1 influenza virus and its impact on vaccine strain selection, diagnostic reagents, and test performance, thereby simplifying communication of such data. IMPORTANCE A fundamental goal in the biological sciences is the definition of groups of organisms based on evolutionary history and the naming of those groups. For influenza A viruses (IAVs) in swine, understanding the hemagglutinin (HA) genetic lineage of a circulating strain aids in vaccine antigen selection and allows for inferences about vaccine efficacy. Previous reporting of H1 virus HA in swine relied on colloquial names, frequently with incriminating and stigmatizing geographic toponyms, making comparisons between studies challenging. To overcome this, we developed an adaptable nomenclature using measurable criteria for historical and contemporary evolutionary patterns of H1 global swine IAVs. We also developed a web-accessible tool that classifies viruses according to this nomenclature. This classification system will aid agricultural production and pandemic preparedness through the identification of important changes in swine IAVs and provides terminology enabling discussion of swine IAVs in a common context among animal and human health initiatives. |
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