Current research in parasitology & vector-borne diseases最新文献

{"title":"Multi-strain compatibility polymorphism between a parasite and its snail host, a neglected vector of schistosomiasis in Africa","authors":"Johannie M. Spaan ,&nbsp;Tom Pennance ,&nbsp;Martina R. Laidemitt ,&nbsp;Nicole Sims ,&nbsp;Jewell Roth ,&nbsp;Yvonne Lam ,&nbsp;Fredrick Rawago ,&nbsp;George Ogara ,&nbsp;Eric S. Loker ,&nbsp;Maurice R. Odiere ,&nbsp;Michelle L. Steinauer","doi":"10.1016/j.crpvbd.2023.100120","DOIUrl":"10.1016/j.crpvbd.2023.100120","url":null,"abstract":"<div><p>Interactions between <em>Schistosoma mansoni</em> and its snail host are understood primarily through experimental work with one South American vector species, <em>Biomphalaria glabrata</em>. However, 90% of schistosomiasis transmission occurs in Africa, where a diversity of <em>Biomphalaria</em> species may serve as vectors. With the long-term goal of determining the genetic and ecological determinants of infection in African snail hosts, we developed genetic models of <em>Biomphalaria sudanica</em>, a principal vector in the African Great Lakes. We determined laboratory infection dynamics of two <em>S. mansoni</em> lines in four <em>B. sudanica</em> lines. We measured the effects of the following variables on infection success and the number of cercariae produced (infection intensity): (i) the combination of parasite and snail line; (ii) the dose of parasites; and (iii) the size of snail at time of exposure. We found one snail line to be almost completely incompatible with both parasite lines, while other snail lines showed a polymorphism in compatibility: compatible with one parasite line while incompatible with another. Interestingly, these patterns were opposite in some of the snail lines. The parasite-snail combination had no significant effect on the number of cercariae produced in a successful infection. Miracidia dose had a strong effect on infection status, in that higher doses led to a greater proportion of infected snails, but had no effect on infection intensity. In one of the snail-schistosome combinations, snail size at the time of exposure affected both infection status and cercarial production in that the smallest size class of snails (1.5–2.9 mm) had the highest infection rates, and produced the greatest number of cercariae, suggesting that immunity increases with age and development. The strongest predictor of the infection intensity was the size of snail at the time of shedding: 1 ​mm of snail growth equated to a 19% increase in cercarial production. These results strongly suggest that infection status is determined in part by the interaction between snail and schistosome genetic lines, consistent with a gene-for-gene or matching allele model. This foundational work provides rationale for determining the genetic interactions between African snails and schistosomes, which may be applied to control strategies.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"3 ","pages":"Article 100120"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10147961/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9405467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Widespread occurrence of copy number variants and fixation of pyrethroid target site resistance in Anopheles gambiae (s.l.) from southern Côte d’Ivoire","authors":"Ruth M.A. Kouamé ,&nbsp;Amy Lynd ,&nbsp;Jackson K.I. Kouamé ,&nbsp;Laura Vavassori ,&nbsp;Kouabénan Abo ,&nbsp;Martin J. Donnelly ,&nbsp;Constant Edi ,&nbsp;Eric Lucas","doi":"10.1016/j.crpvbd.2023.100117","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100117","url":null,"abstract":"<div><p>Resistance to pyrethroid and organophosphate insecticides in the malaria vector <em>Anopheles gambiae</em> (<em>s.l.</em>) is conferred by a variety of genetic mutations, including single nucleotide polymorphisms (SNPs) and copy number variants (CNVs). Knowledge of the distribution of these mutations in mosquito populations is a prerequisite for establishing better strategies for their management. In this study, a total of 755 <em>Anopheles gambiae</em> (<em>s.l.</em>) from southern Côte d’Ivoire were exposed to deltamethrin or pirimiphos-methyl insecticides and were screened to assess the distribution of SNPs and CNVs known or believed to confer resistance to one or other of the insecticide classes. Most individuals from the <em>An. gambiae</em> (<em>s.l.</em>) complex were identified by molecular tests as <em>Anopheles coluzzii</em>. Survival to deltamethrin (from 94% to 97%) was higher than to pirimiphos-methyl (from 10% to 49%). In <em>An. gambiae</em> (<em>s.s.</em>), the SNP in the Voltage Gated Sodium Channel (<em>Vgsc</em>) at the 995F locus (<em>Vgsc</em>-995F) was fixed, while other target site mutations were rare or absent (<em>Vgsc-</em>402L: 0%; <em>Vgsc-</em>1570Y: 0%, Acetylcholinesterase <em>Acel</em>-280S: 14%). In <em>An. coluzzii</em>, <em>Vgsc</em>-995F was the target site SNP found at highest frequency (65%) followed by other target site mutations (<em>Vgsc-</em>402L: 36%; <em>Vgsc-</em>1570Y: 0.33%; <em>Acel</em>-280S: 45%). The <em>Vgsc</em>-995S SNP was not present. The presence of the <em>Ace1</em>-280S SNP was found to be significantly linked to the presence of the <em>Ace1</em>-<em>CNV</em>, <em>Ace1</em>_AgDup. Significant association was found between the presence of the <em>Ace1</em>_AgDup and pirimiphos-methyl resistance in <em>An. gambiae</em> (<em>s.s.</em>) but not in <em>An. coluzzii</em>. The deletion <em>Ace1</em>_Del97 was found in one specimen of <em>An. gambiae</em> (<em>s.s.</em>). Four CNVs in the <em>Cyp6aa/Cyp6p</em> gene cluster, which contains genes of known importance for resistance, were detected in <em>An. coluzzii</em>, the most frequent being Dup 7 (42%) and Dup 14 (26%). While none of these individual CNV alleles were significantly associated with resistance, copy number in the <em>Cyp6aa</em> gene region in general was associated with increased resistance to deltamethrin. Elevated expression of <em>Cyp6p3</em> was nearly associated with deltamethrin resistance, although there was no association of resistance with copy number. Use of alternative insecticides and control methods to arrest resistance spread in <em>An. coluzzii</em> populations is merited.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"3 ","pages":"Article 100117"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49710173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of Felpreva®, a new spot-on formulation containing tigolaner, emodepside and praziquantel, applied as a single application to cats artificially infested with ear mites (Otodectes cynotis)","authors":"Katrin Blazejak ,&nbsp;Alta Viljoen ,&nbsp;Reinier Zwiegers ,&nbsp;Roland Klopper ,&nbsp;Hannah Ringeisen ,&nbsp;Gabriele Petry ,&nbsp;David R. Young ,&nbsp;Douglas Shane ,&nbsp;Jennifer Spruill ,&nbsp;Ronald K. Tessman ,&nbsp;Terry Settje ,&nbsp;Tanja N. Knoppe ,&nbsp;Norbert Mencke","doi":"10.1016/j.crpvbd.2023.100131","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100131","url":null,"abstract":"<div><p>The efficacy of Felpreva® (Vetoquinol), a new spot-on application containing the novel acaricide and insecticide tigolaner in combination with emodepside and praziquantel, was evaluated in cats artificially infested with ear mites (<em>Otodectes cynotis</em>). A total of three pivotal dose confirmation studies were conducted, two of them designed as non-interference studies. Cats were artificially infested with <em>O. cynotis</em> mites and randomly allocated into groups of 8 cats based on pre-treatment mite counts. Cats were treated once on Day 0, either with Felpreva® (14.5 ​mg/kg tigolaner, 3 ​mg/kg emodepside and 12 ​mg/kg praziquantel) or with placebo. Studies with a non-interference design included two additional groups of cats, treated with Profender® spot-on solution (Vetoquinol) (3 ​mg/kg emodepside and 12 ​mg/kg praziquantel) and tigolaner as a mono product (14.5 ​mg/kg tigolaner). Efficacy was evaluated on Day 28/Day 30 based on total live mite counts after ear flushing. Efficacy was claimed when: (i) at least six control cats per group were adequately infested with mites; (ii) calculated efficacy was ≥ 90% based on geometric mean mite counts; and (iii) the difference in mite counts between Felpreva®-treated cats and control cats was statistically significant (<em>P</em> ​≤ ​0.05). In two of the three studies, Felpreva®-treated cats were mite-free (100% efficacy) on Day 28/Day 30 and almost full efficacy (99.6%) was seen in the third study. The difference in mite counts between Felpreva®-treated cats and control cats was significant (<em>P</em> ​&lt; ​0.0001) in all three studies. All control cats were adequately infested in all three studies. The efficacy of Felpreva® against ear mite (<em>Otodectes cynotis</em>) infection in cats was confirmed.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"4 ","pages":"Article 100131"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49778237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geographical analysis of seroprevalence of Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi and Dirofilaria immitis, in clinics and dog shelters in different Mexican states","authors":"Felipe Bedoya ,&nbsp;Frederic Beugnet ,&nbsp;Emilia Tobias ,&nbsp;Erick Garcia-Mendizabal ,&nbsp;Samantha Hay-Parker ,&nbsp;Nancy Montes ,&nbsp;Jose Uribe ,&nbsp;Enrique Mondaca","doi":"10.1016/j.crpvbd.2022.100112","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2022.100112","url":null,"abstract":"<div><p>This study aimed to determine the seroprevalence and geographical distribution of <em>Ehrlichia</em> spp., <em>Anaplasma</em> spp., <em>Borrelia burgdorferi</em> and <em>Dirofilaria immitis</em> in dogs in Mexico, including owned dogs from veterinary clinics with regular medical care and shelter dogs. The Mexican territory was divided into eight geographical regions; 22 out of 32 states were included; 110 veterinary clinics and 53 dog shelters participated. SNAP® 4Dx Plus® (IDEXX® Laboratories) was used to detect antibodies against <em>Ehrlichia</em> spp., <em>Anaplasma</em> spp., <em>Borrelia burgdorferi</em> and <em>Dirofilaria immitis</em> antigens. A total of 3522 apparently healthy dogs were tested, 1648 from clinics and 1874 from shelters. The highest seroprevalence of infection/exposure was found for <em>Ehrlichia</em> spp<em>.</em> (30.9%), followed by <em>Anaplasma</em> spp. (14.6%), <em>D. immitis</em> (5.3%) and <em>B. burgdorferi</em> (0.1%). Significantly more positive dogs were older than 3 years. Regarding differences between facility types, there were only differences for <em>D. immitis</em> which was more prevalent in clinics than in shelters (OR ​= ​1.97; 95% CI: 1.45–2.69; <em>P</em> ​&lt; ​0.0001). Co-infections were detected in 38.4% of the positive samples<em>.</em> Dogs from Mexican states located on the Atlantic and the Pacific coast were significantly more at risk for <em>Ehrlichia</em> spp. and <em>Anaplasma</em> spp. infections than dogs from interior states. Dogs in Atlantic coastal states were more at risk for <em>Dirofilaria immitis</em> infection.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"3 ","pages":"Article 100112"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49710207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infectivity of symptomatic Plasmodium vivax cases to different generations of wild-caught and laboratory-adapted Anopheles arabiensis using a membrane feeding assay, Ethiopia","authors":"Tenaye Ayele ,&nbsp;Biniam Wondale ,&nbsp;Girum Tamiru ,&nbsp;Nigatu Eligo ,&nbsp;Bernt Lindtjørn ,&nbsp;Fekadu Massebo","doi":"10.1016/j.crpvbd.2023.100137","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100137","url":null,"abstract":"<div><p>When measuring human to mosquito transmission of <em>Plasmodium</em> spp., laboratory-adapted (colony) mosquitoes can be utilized. To connect transmission studies to the local epidemiology, it can be important to comprehend the relationship between infectivity in laboratory-adapted (colony) and wild-caught (wild) mosquitoes of the same species. Microscopically confirmed <em>Plasmodium vivax</em> cases were recruited from health facilities in Arba Minch town, and a nested polymerase chain reaction (nPCR) was used for subsequent confirmation. We performed paired membrane-feeding assays using colony <em>An. arabiensis</em> and three generations of wild origin <em>An. arabiensis</em>. <em>Anopheles arabiensis</em> aged 3–6 days were fed after being starved for 8–14 h. Microscopically, the oocyst development was evaluated at day 7 after feeding. Circumsporozoite proteins (CSPs) assay was carried out by enzyme-linked immunosorbent assay (ELISA). In 19 paired feeding experiments, the feeding efficiency was more than doubled in colony (median: 62.5%; interquartile range, IQR: 35–78%) than in wild mosquitoes (median: 28.5%; IQR: 17.5–40%; <em>P</em> &lt; 0.001). Among the 19 <em>P. vivax</em> gametocyte-positive blood samples, 63.2% (<em>n</em> = 12) were infective to wild <em>An. arabiensis</em> and 73.7% (<em>n</em> = 14) were infective to colony <em>An. arabiensis</em>. The median infection rate was twice as high (26%) in the colony than in the wild (13%) <em>An. arabiensis</em>, although the difference was marginally insignificant (<em>P</em> = 0.06). Although the observed difference was not statistically significant (<em>P</em> = 0.19), the median number of oocysts per midgut was more than twice as high (17.8/midgut) in colony than in wild (7.2/midgut) <em>An. arabiensis</em>. The median feeding efficiency was 26.5% (IQR: 18–37%) in F1, 29.3% (IQR: 28–40%) in F2 and 31.2% (IQR: 30–37%) in F3 generations of wild <em>An. arabiensis</em>. Also, no significant difference was observed in oocyst infection rate and load between generations of wild <em>An. arabiensis</em>. CSP rate of <em>P. vivax</em> was 3.1% (3/97; 95% CI: 0.6–8.8%) in wild and 3.6% (3/84; 95% CI: 0.7–10.1%) in colony <em>An. arabiensis</em>. The results of the present study revealed that oocyst infection and load/midgut, and CSP rate were roughly comparable, indicating that colony mosquitoes can be employed for infectivity studies, while larger sample sizes may be necessary in future studies.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"4 ","pages":"Article 100137"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49778373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterising the intensity of insecticide resistance: A novel framework for analysis of intensity bioassay data","authors":"Mara D. Kont ,&nbsp;Ben Lambert ,&nbsp;Antoine Sanou ,&nbsp;Jessica Williams ,&nbsp;Hilary Ranson ,&nbsp;Geraldine M. Foster ,&nbsp;Rosemary S. Lees ,&nbsp;Thomas S. Churcher","doi":"10.1016/j.crpvbd.2023.100125","DOIUrl":"10.1016/j.crpvbd.2023.100125","url":null,"abstract":"<div><p>Insecticide resistance is a growing problem that risks harming the progress made by vector control tools in reducing the malaria burden globally. New methods for quantifying the extent of resistance in wild populations are urgently needed to guide deployment of interventions to improve disease control. Intensity bioassays measure mosquito mortality at a range of insecticide doses and characterise phenotypic resistance in regions where resistance is already detected. These data are increasingly being collected but tend to exhibit high measurement error and there is a lack of formal guidelines on how they should be analysed or compared. This paper introduces a novel Bayesian framework for analysing intensity bioassay data, which uses a flexible statistical model able to capture a wide variety of relationships between mortality and insecticide dose. By accounting for background mortality of mosquitoes, our approach minimises the impact of this source of measurement noise resulting in more precise quantification of resistance. It outputs a range of metrics for describing the intensity and variability in resistance within the sample and quantifies the level of measurement error in the assay. The functionality is illustrated with data from laboratory-reared mosquitoes to show how the lethal dose varies within and between different strains. The framework can also be used to formally test hypotheses by explicitly considering the high heterogeneity seen in these types of data in field samples. Here we show that the intensity of resistance (as measured by the median lethal dose (LC₅₀) of insecticide) increases over 7 years in mosquitoes from one village in Burkina Faso but remains constant in another. This work showcases the benefits of statistically rigorous analysis of insecticide bioassay data and highlights the additional information available from this and other dose-response data.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"4 ","pages":"Article 100125"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10338328/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9828409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plague mitigation for prairie dog and black-footed ferret conservation: Degree and duration of flea control with 0.005% fipronil grain bait","authors":"David A. Eads ,&nbsp;Travis M. Livieri ,&nbsp;Phillip Dobesh ,&nbsp;John P. Hughes ,&nbsp;Jason Fly ,&nbsp;Holly Redmond ,&nbsp;Eddie Childers ,&nbsp;Matthew S. Schwarz ,&nbsp;Dean E. Biggins","doi":"10.1016/j.crpvbd.2023.100124","DOIUrl":"10.1016/j.crpvbd.2023.100124","url":null,"abstract":"<div><p>Sylvatic plague, a primarily flea-borne zoonosis, is a significant threat to prairie dogs (<em>Cynomys</em> spp., PDs) and their specialized predators, endangered black-footed ferrets (<em>Mustela nigripes</em>, BFFs). Host-fed fipronil baits have proven effective in controlling fleas on PDs for the purposes of plague mitigation and BFF conservation. Currently, annual treatments are the norm. We tested the long-term efficacy of fipronil bait treatments with black-tailed PDs (<em>C. ludovicianus</em>, BTPDs) and BFFs in South Dakota, USA. During 2018–2020, we provided BTPDs on 21 sites with grain bait formula, laced with 0.005% fipronil (50 ​mg/kg); 18 non-treated sites functioned as baselines. In 2020–2022, we live-trapped, anesthetized, and combed BTPDs for fleas. Flea control was significant for at least 639–885 days. Flea abundance on the treated sites was &lt; 0.5 fleas/BTPD for ∼750 days. During 2020–2022, we sampled BFFs for fleas on 4 BTPD colonies treated with fipronil grain bait and 8 non-treated colonies. Flea control was significant with BFFs, but flea abundance began to rebound within ∼240 days post-treatment. When feasible, the combination of insecticide treatments, such as fipronil baits, and BFF vaccination against plague provide a “two-pronged” protection approach for these endangered carnivores. If fipronil bait treatments are less effective with predatory BFFs than PDs, as found herein, the “two-pronged” approach might be used to protect BFFs and biennial fipronil bait treatments might be used to protect PDs. If BFF vaccination is not possible, or few BFFs can be vaccinated, annual fipronil bait treatments might be used as a precaution to protect BFFs. Flea densities might be surveyed to determine when/where more frequent treatments seem useful.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"3 ","pages":"Article 100124"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10250916/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9618621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating vector control within an emerging agricultural system in a region of climate vulnerability in southern Malawi: A focus on malaria, schistosomiasis, and arboviral diseases","authors":"Christopher M. Jones ,&nbsp;Anne L. Wilson ,&nbsp;Michelle C. Stanton ,&nbsp;J. Russell Stothard ,&nbsp;Federica Guglielmo ,&nbsp;James Chirombo ,&nbsp;Lindiwe Mafuleka ,&nbsp;Rose Oronje ,&nbsp;Themba Mzilahowa","doi":"10.1016/j.crpvbd.2023.100133","DOIUrl":"10.1016/j.crpvbd.2023.100133","url":null,"abstract":"<div><p>Infectious diseases are emerging at an unprecedented rate while food production intensifies to keep pace with population growth. Large-scale irrigation schemes have the potential to permanently transform the landscape with health, nutritional and socio-economic benefits; yet, this also leads to a shift in land-use patterns that can promote endemic and invasive insect vectors and pathogens. The balance between ensuring food security and preventing emerging infectious disease is a necessity; yet the impact of irrigation on vector-borne diseases at the epidemiological, entomological and economic level is uncertain and depends on the geographical and climatological context. Here, we highlight the risk factors and challenges facing vector-borne disease surveillance and control in an emerging agricultural ecosystem in the lower Shire Valley region of southern Malawi. A phased large scale irrigation programme (The Shire Valley Transformation Project, SVTP) promises to transform over 40,000 ha into viable and resilient farmland, yet the valley is endemic for malaria and schistosomiasis and experiences frequent extreme flooding events following tropical cyclones. The latter exacerbate vector-borne disease risk while simultaneously making any empirical assessment of that risk a significant hurdle. We propose that the SVTP provides a unique opportunity to take a One Health approach at mitigating vector-borne disease risk while maintaining agricultural output. A long-term and multi-disciplinary approach with buy-in from multiple stakeholders will be needed to achieve this goal.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"4 ","pages":"Article 100133"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10412864/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9990491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy and safety of Felpreva®, a spot-on formulation for cats containing emodepside, praziquantel and tigolaner against experimental infestation with the Australian paralysis tick Ixodes holocyclus","authors":"Florian Roeber ,&nbsp;Chrissie Jackson ,&nbsp;Michael Chambers ,&nbsp;Veronica Smith ,&nbsp;Jane Hume ,&nbsp;Katrin Blazejak ,&nbsp;Norbert Mencke","doi":"10.1016/j.crpvbd.2023.100123","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100123","url":null,"abstract":"<div><p>The Australian paralysis tick <em>Ixodes holocyclus</em> continues to be a serious threat to companion animals along Australia’s east coast. The tick produces a potent neurotoxin which causes a rapidly ascending flaccid paralysis, which if left untreated, can result in the death of the animal. There is currently only a limited number of products registered in Australia for the treatment and control of paralysis ticks in cats. Felpreva® is an effective spot-on combination containing emodepside, praziquantel and tigolaner. To investigate the therapeutic and long-term persistent efficacy of Felpreva® (2.04% w/v emodepside, 8.14% w/v praziquantel and 9.79% w/v tigolaner) against experimental infestation with <em>I. holocyclus</em> in cats, two studies were undertaken. Fifty cats were included in the studies on study Day -17. These cats were immunized against paralysis tick holocyclotoxin prior to the study commencing. Immunity to holocyclotoxin was confirmed with a tick carrying capacity (TCC) test conducted prior to treatment. Cats were treated once on Day 0. Group 1 cats were treated with the placebo formulation and Group 2 cats were treated with Felpreva®. Cats were infested on Days -14 (tick carrying capacity test), 0, 28, 56, 70, 84 and 91 (weeks 4, 8, 10, 12 and 13). Ticks were counted on cats 24 h, 48 h and 72 ​h post-treatment and infestation, except during the tick carrying capacity test when they were counted approximately 72 ​h post-infestation only. The 24-h and 48-h assessments were conducted without removing the ticks. The ticks were assessed, removed and discarded at the 72-h assessment time-points. Significant differences in total live tick counts at ∼24 h, ∼48 h and ∼72 ​h post-infestation were observed between the treatment and control group. Differences were significant (<em>P</em> ​&lt; ​0.05 to ​&lt; ​0.001) in all instances. Treatment efficacies of 98.1–100% were observed ∼72 ​h post-infestation through to 13 weeks (94 days) post-treatment. These results show that a single application of Felpreva® provides effective treatment and control against induced infestation with paralysis ticks for 13 weeks.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"4 ","pages":"Article 100123"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49791524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Larviciding intervention targeting malaria vectors also affects Culex mosquito distribution in the city of Yaoundé, Cameroon","authors":"Abdou Talipouo ,&nbsp;Patricia Doumbe-Belisse ,&nbsp;Carmène S. Ngadjeu ,&nbsp;Landre Djamouko-Djonkam ,&nbsp;Elysée Nchoutpouen ,&nbsp;Roland Bamou ,&nbsp;Nadège Sonhafouo-Chiana ,&nbsp;Audrey Paul Marie Mayi ,&nbsp;Gisèle Aurélie Dadji Foko ,&nbsp;Parfait Awono-Ambene ,&nbsp;Sévilor Kekeunou ,&nbsp;Charles S. Wondji ,&nbsp;Christophe Antonio-Nkondjio","doi":"10.1016/j.crpvbd.2023.100136","DOIUrl":"https://doi.org/10.1016/j.crpvbd.2023.100136","url":null,"abstract":"<div><p>Although <em>Culex</em> species are considered to be equally affected by control measures targeting malaria vectors, there is still not enough evidence of the impact of interventions such as larviciding on the distribution of these mosquito species. The present study assessed the impact of a larviciding trial targeting malaria vectors on <em>Culex</em> mosquito species in the city of Yaoundé, Cameroon. A cluster randomized trial comparing 13 treated clusters and 13 untreated clusters was implemented. Data were collected at baseline and during the larviciding intervention, from March 2017 to November 2020. The microbial larvicide VectoMax G was applied once every 2 weeks in the intervention areas. Adult mosquitoes were collected using CDC light traps in both intervention and non-intervention areas and compared between arms. Globally, larviciding intervention was associated with 69% reduction in aquatic habitats with <em>Culex</em> larvae and 36.65% reduction of adult <em>Culex</em> densities in houses. Adult <em>Culex</em> densities were reduced both indoors (35.26%) and outdoors (42.37%). No change in the composition of <em>Culex</em> species was recorded. The study suggests a high impact of larviciding on <em>Culex</em> mosquito species distribution. The impact of the intervention can be improved if typical <em>Culex</em> breeding habitats including pit latrines are targeted.</p></div>","PeriodicalId":94311,"journal":{"name":"Current research in parasitology & vector-borne diseases","volume":"4 ","pages":"Article 100136"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49791531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}