Parasites & Vectors最新文献

{"title":"Winter activity and virus infection of Culicoides biting midges (Diptera: Ceratopogonidae) in German livestock housing before and during the 2024 BTV-3 outbreak.","authors":"Anja Voigt, Helge Kampen, Martin Beer, Kerstin Wernike, Dorothee Scheuch, Franziska Sick, Sophie Zeiske, Doreen Werner","doi":"10.1186/s13071-026-07620-w","DOIUrl":"10.1186/s13071-026-07620-w","url":null,"abstract":"<p><strong>Background: </strong>Despite its importance for Culicoides-borne disease risk assessment, the winter activity of species of this biting midge genus remains poorly characterized. Moreover, information on virus circulation in winter-active Culicoides vectors, both under endemic conditions and during outbreaks, is almost non-existent.</p><p><strong>Methods: </strong>UV-light traps to collect Culicoides biting midges were operated once a week for 24 h in cattle, sheep, goat and horse stables at 12 to 55 locations during four consecutive winter periods (November 1 to March 31, 2021 to 2025) throughout Germany. Collected females of the genus Culicoides were morphologically assigned to Obsoletus Group or Pulicaris Complex. Temperature data were recorded to relate biting midge activity to temperatures. Screening for bluetongue virus (BTV), Schmallenberg virus and epizootic hemorrhagic disease virus was done by real-time RT-PCR on 1,581 pools (46,358 females) of both groups collected before (winter 2022/2023) and during the BTV serotype 3 (BTV-3) outbreak (winters 2023/2024 and 2024/2025).</p><p><strong>Results: </strong>Culicoides collections displayed notable variation between sites and months. November and March accounted for 95% of captures, while mid-winter months (December to February) yielded only 5%, with January and February each contributing 1% of total captures. The March 2024 and 2025 activity peaks coincided with mild temperatures and the inclusion of new monitoring sites, suggesting that one or both factors contributed. Although blood-fed females were very rare during mid-winter, their abundance often exceeded the EU threshold for parous Culicoides to define a vector-free period of < 5 individuals per trap and night. However, only a single Culicoides pool from November 2024 tested positive for BTV-3-RNA. All other pools were negative for all three viruses.</p><p><strong>Conclusions: </strong>Potential Culicoides vectors are active and feed on blood in livestock housings during wintertime. The presence of blood-fed females, exceeding the EU threshold, challenges the concept of a 'vector-free period'. However, despite extensive monitoring over four years including outbreak conditions, only one virus-positive Culicoides pool was detected during winter. Combined with the very low number of biting midges and the temperatures not allowing virus replication in arthropods, virus circulation during wintertime appears to be hardly existent even under endemic or outbreak conditions. Considering both Culicoides activity and virus circulation, the findings suggest that the risk of BTV infection in ruminants via biting midges during the central European winter (December to March) is negligible. BTV overwintering in central Europe likely depends on either rare infection events in ruminants and vectors during winter that sustain viremia until spring, or on persistence mechanisms that are currently unknown.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148887518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A case of misleading conclusion: a critical reassessment of methodological and interpretive flaws of a recent meta-analysis on the vector role of cat fleas in feline hemotropic Mycoplasma species.","authors":"Charlotte O Moore, Erin Lashnits, Michael Lappin, Edward B Breitschwerdt","doi":"10.1186/s13071-026-07315-2","DOIUrl":"10.1186/s13071-026-07315-2","url":null,"abstract":"","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13527973/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148865988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low observed perioperative complication rates associated with surgical sterilization of 1,011 heartworm-infected dogs using standard, unmodified anesthesia and surgical protocols.","authors":"Jessie L Dyer, Linda S Jacobson, Maria A Serrano, Brian A DiGangi, Joey Friedman, Hannah M Garcia, Mia K Cuccinello, Julie K Levy","doi":"10.1186/s13071-026-07514-x","DOIUrl":"10.1186/s13071-026-07514-x","url":null,"abstract":"<p><strong>Background: </strong>Shelters routinely sterilize dogs before adoption using standardized, high-volume protocols. Many also admit heartworm-positive dogs, which often experience reduced adoption appeal, longer shelter stays and higher euthanasia risk. Sterilizing these dogs before melarsomine treatment can expedite placement, but safety data on using standard, unmodified protocols remain limited. This study investigated perioperative complications in dogs with mild to moderate heartworm disease (HWD) undergoing sterilization prior to melarsomine therapy.</p><p><strong>Methods: </strong>This was a retrospective observational study of 1,011 clinically stable shelter dogs with Class 1-2 HWD treated between 2014 and 2024. All received a standardized anesthetic protocol of dexmedetomidine, ketamine, butorphanol, and isoflurane. Surgeries were classified as routine or complex. Complications were categorized as major (life-threatening events, severe surgical problems, or aborted procedures) or minor (self-limiting issues or those requiring minimal, non-surgical intervention).</p><p><strong>Results: </strong>The study included 1,011 dogs (440 females, 571 males); 92.2% underwent routine spay-neuter procedures. No perioperative deaths occurred. Twelve dogs (1.2%) experienced major complications, including three anesthetic events of unclear etiology that could not be definitively attributed to HWD, and nine surgical-site complications requiring revision. Minor complications occurred in 39 dogs (3.9%), primarily superficial incisional issues (3.6%) and transient hematuria (< 1%). Most complications were superficial surgical‑site issues commonly observed after routine sterilization, and there was no evidence of an unexpectedly high rate of cardiopulmonary events in this heartworm‑positive cohort.</p><p><strong>Conclusions: </strong>Unmodified high-volume anesthetic and surgical protocols were associated with low perioperative complication rates in a selected population of dogs with Class 1-2 HWD. Sterilizing dogs with mild to moderate HWD before adulticide therapy appears safe when using standard spay-neuter protocols and supports earlier adoption, improved shelter throughput, and efficient resource use without compromising patient safety.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13523282/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148840937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the trūRapid^™ FOUR heartworm antigen test: a reliable point-of-care diagnostic tool for heartworm detection in dogs.","authors":"Haichen Song, Chinta M Lamichhane, Xiuli Yang, Meera Surendran-Nair, Frances Moore, Graham Bilbrough, Michelle D Evason, Demitria M Vasilatis, Jennifer L Willcox, Christian M Leutenegger, Pablo D Jimenez Castro","doi":"10.1186/s13071-026-07630-8","DOIUrl":"10.1186/s13071-026-07630-8","url":null,"abstract":"<p><strong>Background: </strong>Heartworm disease, caused by Dirofilaria immitis, is a globally distributed and clinically significant cardiopulmonary condition affecting dogs and other animal species. Dogs typically lack overt clinical signs in the early stages of infection, and disease progression can lead to worsening clinical signs and poor prognosis. The purpose of this study was to evaluate the performance of the tr?Rapid™ FOUR heartworm antigen test (Antech Diagnostics) for the detection of D. immitis antigen in canine serum samples and to compare its performance with another commercially available point of care (POC) heartworm antigen test, specifically the SNAP® 4DX® Plus (IDEXX), using DiroCHEK® (Zoetis) as the reference test.</p><p><strong>Methods: </strong>A total of 350 canine remnant serum samples were evaluated using tr?Rapid™ FOUR, SNAP® 4DX® Plus, and DiroCHEK® as per manufacturers' instructions.</p><p><strong>Results: </strong>For samples positive at DiroCHEK® (n = 149), the sensitivity of the tr?Rapid™ FOUR heartworm antigen test was 98.7% (95% CI 94.3-99.6%), with a specificity of 100% (95% CI 98.2-100%) for samples negative at DiroCHEK® (n = 201). The tr?Rapid™ FOUR showed excellent agreement with another available POC test, the SNAP® 4DX® Plus (0.994 ? agreement, 95% CI 0.983-1.000).</p><p><strong>Conclusions: </strong>The findings demonstrate that the tr?Rapid™ FOUR heartworm antigen test provides reliable diagnostic accuracy, ease of use, and a fast time to result (10 min), making it a robust POC option for detecting canine heartworm infection. Its performance is comparable to the reference laboratory ELISA test, DiroCHEK®, and another commercially available POC test, SNAP® 4DX® Plus. Overall, the results support the use of the tr?Rapid™ FOUR heartworm antigen test as a dependable clinical tool for the detection and management of heartworm infection in dogs.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148887419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the performance of trūRapid™ FOUR heartworm antigen test for early detection in experimentally infected dogs in comparison to other point-of-care tests.","authors":"Pabasara Weerarathne, Tiana L Sanders, Alexa Starnes, Maureen A Kelly, Pablo D Jimenez Castro, Frances M Moore, Demitria M Vasilatis, Christian M Leutenegger, Chinta Lamichhane, Haichen Song, Guilherme G Verocai","doi":"10.1186/s13071-026-07450-w","DOIUrl":"https://doi.org/10.1186/s13071-026-07450-w","url":null,"abstract":"<p><strong>Background: </strong>The American Heartworm Society (AHS) recommends diagnosing canine heartworm (HW) infection using both antigen and microfilaria detection tests. Antigen-antibody immune complexes may block antigen detection. Therefore, the AHS recommends immune complex dissociation (ICD) via heat treatment for discordant cases. The trūRapid™ FOUR antigen test kit (Antech Diagnostics) is a novel commercially available point-of-care (POC) device. This study evaluated the performance of trūRapid™ FOUR compared to other commercially available POC tests, namely SNAP^® 4Dx^® Plus (IDEXX), VETSCAN^® Flex4 (Zoetis), and a plate-based assay, DiroCHEK^® (Zoetis), for early detection of HW infection in experimentally infected dogs.</p><p><strong>Methods: </strong>Archival frozen serum samples from six purpose-bred beagles experimentally infected with Dirofilaria immitis were collected weekly for 5.5 months, from week 1 to week 22 post-infection. Sera were tested for the detection of HW antigen, pre- and post-ICD, via heat treatment (103 °C for 10 min in a heat block) using each of the commercial antigen tests. DiroCHEK^® results were interpreted using optical density readings.</p><p><strong>Results: </strong>HW antigen was not detected in samples collected from week 1 through week 19. In week 20, the trūRapid™ FOUR, SNAP^® 4Dx^® Plus, and VETSCAN^® Flex4 detected HW antigen in one out of six samples (16.7%) post-ICD, while DiroCHEK^® detected two (33.3%) post-ICD. In week 21, the trūRapid™ FOUR, SNAP^® 4Dx^® Plus, and DiroCHEK^® detected HW antigen in four out of the five (80%) post-ICD samples, whereas the VETSCAN^® Flex4 detected three out of the four (75%) post-ICD samples. In week 22, HW antigen was detected in one of six (16.7%) pre-ICD by all tests; trūRapid™ FOUR, SNAP^® 4Dx^® Plus, and DiroCHEK^® detected HW antigen on all six (100%) samples post-ICD, while VETSCAN^® Flex4 detected four of six samples (66.7%).</p><p><strong>Conclusions: </strong>Our findings indicate that trūRapid™ FOUR and other commercially available antigen detection tests can detect HW antigen as early as 5 months post-infection when serum is subjected to heat treatment. The performance of trūRapid™ FOUR is comparable to other widely used commercial antigen kits. Its ease of use and ability to detect HW infection earlier in the course of antigenemia makes it an excellent POC diagnostic tool, allowing for prompt clinical intervention, and increasing patient quality of life.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491578/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148795663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The history of Wolbachia and heartworm.","authors":"A Vismarra, M Fozzer, J W McCall, M Genchi, L Venco, R Morchón García, C Bazzocchi, C Genchi, L Kramer, C Bandi","doi":"10.1186/s13071-026-07397-y","DOIUrl":"10.1186/s13071-026-07397-y","url":null,"abstract":"<p><p>Wolbachia is the most widespread endosymbiont in animals, and its discovery in Dirofilaria immitis significantly advanced our understanding of heartworm disease (HWD). In 1995, Sironi and colleagues from the universities of Milan and Pavia, Italy, published a study titled \"Molecular evidence for a close relative of the arthropod endosymbiont Wolbachia in a filarial worm\" (Mol Biochem Parasitol. 74:223-7, 1995). In the 1970s, intracellular bacteria were observed in filarial nematodes by electron microscopy, but no one understood what they were or why they were there. There had been previous reports on the anti-filarial effects of tetracycline, but no connection with these bacteria had been made. Many years later, these bacteria were identified as belonging to the genus Wolbachia, marking a new chapter in filarial research. As soon as Wolbachia had been described in heartworms, there was a flurry of excitement in the scientific community. By 1999, Wolbachia had been described in a further nine species of animal and human filarial nematodes. Subsequent studies strongly suggested that Wolbachia are obligatory mutualist symbionts of D. immitis, and related research then focused on targeting Wolbachia in the treatment of HWD. Studies on the effects of doxycycline treatment in D. immitis-infected dogs reported that bacterial depletion in adult worms, elimination of microfilariae, and adult worm death were more effective when antibiotics were combined with macrocyclic lactones, and that use of this combination also avoided the deleterious post-adulticide effects of treatment with melarsomine. Dirofilaria immitis-infected dogs develop an immune response to Wolbachia, which likely contributes to the immunopathology of HWD. Insights into how D. immitis and Wolbachia interact were gained in 2012, when genome sequencing of these organisms was completed.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491582/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148796485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retrospective review of clinical and anesthetic findings in 164 heartworm-positive dogs undergoing spay-neuter surgery.","authors":"Michelle Salob, Brian A DiGangi","doi":"10.1186/s13071-026-07266-8","DOIUrl":"https://doi.org/10.1186/s13071-026-07266-8","url":null,"abstract":"<p><strong>Background: </strong>Timing of spay-neuter surgery in heartworm-positive dogs has been a concern, primarily due to perceived risk of anesthetic complications secondary to cardiovascular compromise. In shelter settings, timing of spay-neuter surgery impacts length of stay and ultimate chance of adoption for heartworm-positive dogs, yet up to 13% of animal shelters may delay spay-neuter procedures until after adulticidal therapy.</p><p><strong>Methods: </strong>This retrospective review of medical records describes clinical and anesthetic monitoring parameters of heartworm-positive dogs presented for elective spay-neuter surgery in a veterinary student clinical training program. Dogs were assessed for anesthetic/surgical candidacy based on physical examination findings alone and experienced standardized anesthetic protocols.</p><p><strong>Results: </strong>Patients included 94 females, 69 males, and one intersex patient with ages ranging from 6 months to 15 years. The heartworm status of 73 dogs (44.5%) was unknown at the time of anesthesia and surgery. Noteworthy cardiopulmonary findings on preoperative physical examination included two dogs with a cough and normal heart and lung sounds on auscultation, and five dogs with heart murmurs (grade 2, n = 2; grade 3, n = 3) with normal lung sounds on auscultation. Two of the dogs with a grade 3 heart murmur were evaluated by a veterinary cardiologist; one was determined to have no pulmonary artery disease, and one was identified as previously diagnosed with mitral valve insufficiency. Average anesthetic time was 98.6 min (range 13-285 min.), 50.3 min for males and 133.7 min for females. Average oxygen saturation (SpO₂) reading was 96% (range 89-99%); hypoxemia (< 90%) was identified at five specific time points in four patients. Bradycardia (< 60 beats per minutes [bpm]) was identified in four patients (2.4%). There were no perioperative anesthetic emergencies or deaths. A total of nine perioperative surgical complications were identified, six of which were unrelated to heartworm status. The remaining three reports consisted of blood-tinged mucus identified on the endotracheal tube after extubation.</p><p><strong>Conclusions: </strong>There was no evidence of increased risk of anesthetic or surgical complications in heartworm-positive dogs when screening was limited to a preoperative physical examination and standardized anesthetic protocols were used for elective sterilization procedures.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491864/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148796444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seroprevalence and molecular surveillance of Dirofilaria immitis in shelter dogs from central New Mexico, USA.","authors":"Maureen A Kelly, Alexa Starnes, Mary Schech, Erin Clarke, Rafael A N Ramos, Hassan Hakimi, Pabasara Weerarathne, Guilherme G Verocai","doi":"10.1186/s13071-026-07341-0","DOIUrl":"https://doi.org/10.1186/s13071-026-07341-0","url":null,"abstract":"<p><strong>Background: </strong>Dirofilaria immitis, the causative agent of canine heartworm disease, is a mosquito-borne filarial nematode, endemic to most of North America. Clinical signs may include coughing, exercise intolerance, abnormal heart sounds, and lethargy, which can lead to heart failure and death in severe cases. For accurate diagnosis, the American Heartworm Society (AHS) recommends testing dogs annually for the detection of heartworm antigens and microfilariae. In this study, we assessed the prevalence and potential risk factors for D. immitis in dogs from Albuquerque, New Mexico, using antigen and microfilariae detection tests.</p><p><strong>Methods: </strong>In 2023, serum and whole-blood samples (n = 402) were collected from dogs in Albuquerque, New Mexico, as part of a larger study to detect Onchocerca lupi. Serum samples were screened for D. immitis using a commercially available antigen-detection ELISA (DiroCHEK^®, Zoetis) with pre- and post-immune complex dissociation (ICD) via heat treatment, although this is not currently recommended by AHS. Following genomic DNA extraction, we also screened whole blood using a newly optimized probe-based real-time polymerase chain reaction (qPCR) assay. To assess the potential association between D. immitis presence and risk factors, including age, sex, breed group, and coat color, a univariate analysis was performed using Fisher's exact test or the chi-squared test.</p><p><strong>Results: </strong>Serum of 4 (0.99%) dogs tested antigen-positive pre-ICD, while 14 (3.47%) dogs tested antigen-positive post-ICD. We did not detect any positive dogs for D. immitis microfilariae by the probe-based qPCR. No risk factors were associated with the detection of the D. immitis antigen in this dog population.</p><p><strong>Conclusions: </strong>Although microfilariae were not detected in this study, it is possible that infections were in the early stages of disease progression, with D. immitis detected in pre- and post-ICD via antigen testing. Low seroprevalence and the absence of microfilariae DNA detected highlight the importance of using both pre- and post-ICD antigen detection alongside molecular-based microfilariae tests, particularly for companion animals living in low-endemic regions and for shelter populations that are less likely to be on heartworm prevention.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491768/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148796462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potential risk of heartworm infection in the United States of America and its projected incidence by 2100.","authors":"Rodrigo Morchón, Iván Rodríguez-Escolar, Manuel Collado-Cuadrado, Elena Infante González-Mohino, José Alberto Montoya-Alonso, Elena Carretón, Alfonso Balmori-de la Puente","doi":"10.1186/s13071-026-07293-5","DOIUrl":"https://doi.org/10.1186/s13071-026-07293-5","url":null,"abstract":"<p><strong>Background: </strong>Heartworm disease, caused by the parasitic roundworm Dirofilaria immitis, is a vector-borne zoonosis transmitted by culicid mosquitoes and widely distributed in the USA, where prevalence is highest in the southeastern states. Transmission dynamics are influenced by environmental and anthropogenic factors, and climate change is expected to modify its distribution. Within a One Health framework, this study generates monthly and annual risk maps for heartworm transmission in the USA and projects the habitat suitability of vectors to the year 2100.</p><p><strong>Methods: </strong>Ecological niche models were constructed for Aedes albopictus and Aedes vexans using MaxEnt and occurrence data from the Global Biodiversity Information Facility (GBIF). Bioclimatic variables from WorldClim and environmental layers related to hydrology, vegetation, and human activity obtained from free global datasets were selected after multicollinearity testing. Growing degree days (GDD) were calculated to estimate monthly and annual D. immitis generations using CHELSA (Climatologies at high resolution for the Earth's land surface) temperature data. Habitat suitability models were combined with parasite generations to produce infection risk maps for the USA, validated against clinical case data. Future projections to 2100 were generated under the RCP (Representative Concentration Pathways) 8.5 scenario.</p><p><strong>Results: </strong>Our results indicate that the highest risk of infection is concentrated in the southeastern states and Gulf Coast, where conditions are warmer and more humid, at least during certain periods of the year. In contrast, risk decreases towards the west, particularly in the Rocky Mountains, Sierra Nevada, and the deserts of Arizona and Nevada. Regarding seasonal variation, infection risk remains very low across most of the USA during the winter months, gradually increasing month by month and peaking in summer. Finally, projections for 2100 suggest a rise in infection risk, particularly in Midwest and Northeast regions and higher-altitude areas.</p><p><strong>Conclusions: </strong>Heartworm transmission risk in the USA shows strong geographical expansion potential driven by climate conditions. Our risk maps reveal emerging areas of suitability and provide an early warning tool for One Health surveillance and prevention strategies.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491600/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148796438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluorescence videography for the rapid and automated in-clinic detection of microfilariae.","authors":"Britt Ripley, Mackenzie Smith, Alex Chen, Kevin Calcote, Andrew R Moorhead, Elyssa Campbell, Paul Slusarewicz","doi":"10.1186/s13071-026-07486-y","DOIUrl":"10.1186/s13071-026-07486-y","url":null,"abstract":"<p><strong>Background: </strong>Heartworm infection is a serious cause of both morbidity and mortality in canids. Current guidelines from professional bodies recommend annual testing using both molecular (ELISA/PCR/Lateral Flow) and microscopic (detection of microfilariae in blood) testing. The inconvenience of the latter, however, presents a barrier to some clinicians towards adherence to these guidelines. We have recently developed a fully automated, rapid and hands-free test that uses videography coupled to computer vision analysis to detect and enumerate blood-borne microfilariae.</p><p><strong>Methods: </strong>Here we describe the performance of this test compared to a common clinical option - the 20 μL wet mount. Multiple counts were conducted by both methods on serially diluted infected blood to determine count correlations and on highly diluted and negative samples to compare sensitivities and specificities.</p><p><strong>Results: </strong>Automated counts correlated well (R² = 0.9851) at microfilarial concentrations of up to 1000 microfilariae/mL, after which the automated counts began to plateau as microfilariae began to overlap and became more difficult to distinguish from each other. Within the linear range, the automated method counted more than 10-times as many microfilariae in the same blood samples than the manual method; this translated to a sensitivity of 100% at approximately 50 microfilariae/mL compared to 60% for the manual wet mount. After a further 2-fold dilution the sensitivity of the manual method dropped to 10% while that of the automated remained at 100%.</p><p><strong>Conclusion: </strong>These results indicate that the automated system is a viable option to replace current manual options in-clinic while combining superior sensitivity with greater convenience.</p>","PeriodicalId":19793,"journal":{"name":"Parasites & Vectors","volume":"19 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491700/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148796500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}