HARRISON

Brazilian Journal of Veterinary Medicine

This study aimed to investigate the presence of Dirofilaria immitis microfilaremia in dogs from two regions of the state of Rio de Janeiro, Brazil, where heartworm infections are highly prevalent. Blood samples were collected from dogs aged > 12 months, independent of the use of preventatives. All samples obtained and analyzed using Knott's modified test by the investigators. A total of 133 blood samples were tested, and D. immitis microfilariae were detected in 29 of them, resulting in an occurrence of 21.8%. The percentage of dogs with microfilaremia detected raises concerns for pet families, one health professionals, and small animal practitioners. Microfilaremic dogs are the richest source of infection for the mosquitoes, increasing the risk of transmission. Therefore, the stakeholders in One Health must raise concerns regarding the health of wild animals, as wild canids and other species of wild animals are exposed to the risk of D. immitis infection. In addition, humans can get infected and develop human pulmonary dirofilariasis. In conclusion, the presence of dogs with microfilaremia potentiates opportunities for D. immitis transmission, exposing all animals, wild or domestic, human or non-human to the disease.

Journal of Advanced Veterinary and Animal Research

Objective: This study was designed to assess the prevalence and the associated risk factors (e.g., sex, age, breed, management system and climate) of Dirofilaria immitis in dogs in Makurdi metropolis in Nigeria. Materials and methods: Prevalence study of canine heartworm disease in dogs was conducted over a period of six months covering five localities of Makurdi metropolis in Benue State, Nigeria. A total of 186 blood samples were collected from apparently healthy and sick dogs, and the samples were examined for the presence of microfilaria between September 2015 and February 2016. Three methods (wet mount, Buffy coat and modified Knott's techniques) were used for the examination of the samples. The Packed Cell Volume (PCV) and complete blood count for each sample were also determined. Results: Out of the 186 dogs, 4 (2.15%) were found to be positive for the presence of microfilaria. Out of the 4 positive cases, 3 (1.61%) were microfilaria and 1 (0.54%) was unidentified motile parasite. A total of 104 females were examined and only 1 (0.96%) was positive, while 3 (3.66%) males out of 82 examined were positive. Out of 141 older dogs examined, 4 (2.84%) were positive. Hematology of the positive dogs revealed mild anemia and moderate thrombocytopenia with Mean±SD of 34.8±15.30% and 108±60.81x10 9 /L, respectively. Conclusion: The study confirms Knott's technique to be the most sensitive in the diagnosis of dirofilariasis in dogs using parasitological techniques. The findings confirm the occurrence of D. immitis in dogs in Makurdi with low prevalence and that the general public are at high risk of spreading infection from the dogs. Infection is more in male and adult dogs. This work can assist in planning appropriate strategies for controlling and prevention of D. immitis infection in Nigeria.

Acta Agraria Kaposváriensis

Dirofilaria repens causes skin worm infection in canid sepcies and humans. This parasite needs mosquitoes as intermediate hosts in their lifecycle. By warming of the global climate, more and more areas become suitable mosquito habitats. Therefore, mosquito transmitted diseases can emerge in new areas. In this study, the authors investigated the dog population of the south Transdanubia, the southernmost part of Hungary to determine the average D. repens prevalence. By Knott’s test and molecular confirmation of infected status, 11.7% prevalence could be detected in 95 domestic dogs. In risk analysis, urban residence and female sex proved to carry high risk of infection. On the other hand, age, breed, hair length showed no impact on infection status. Though all these features seemed important in mosquito biting success, this study could not support the relevance of them.

2009

Heartworm disease is caused by Dirofilaria immitis a zoonotic, vector-borne parasite and one of the most pathogenic nematode parasites of the dog. The epidemiological status of this parasitosis in Algeria stays to this day unknown even though this country has the ideal biotope to the development of this disease. The aim of this study was to investigate the prevalence of D. immitis infection in dogs from Algiers, in the north of Algeria. Blood samples were collected from 184 dogs from November 2006 to September 2007 and were examined by the modified Knott method to detect circulating microfilaria. A total of 34 subjects were microfilaria positive, giving a prevalence value of 18.48%. All the samples were further tested by antigen-ELISA in order to detect dogs with prepatent or occult heartworm infections. The prevalence rose to 24.46% (with 45 seropositives dogs). More male (14.13%) than female (10.33%) dogs were affected in this study, although there was no significant difference between both groups. With regard to general health status, our data showed a high prevalence of 18.48% of asymptomatic carriers of the parasite D. immitis, only 5.98% of the positive samples were from unhealthy dogs. The difference was statistically significant (p < 0.05). This first report on the status of D. Immitis infection in domestic dogs in Algiers, suggests that heartworm treatment and adequate prophylaxis should be undertaken to control D. Immitis infection in the canine population of Algiers city in Algeria.

Parasites & Vectors, 2013

Background: The occurrence of infections by Dirofilaria immitis in canine and human populations depends on several factors linked to both the definitive and intermediate hosts. Little data are available on the risk of human and dog exposure to D. immitis in endemic areas. Data collected on dog-and human-bait traps in endemic areas of north-eastern Italy were used to estimate the likelihood of a receptive host coming into contact with an infected vector. Methods: From 1997 to 1999, mosquitoes were collected from three sampling sites of north-eastern Italy on D. immitis microfilaraemic dogs and on human baits. The bite/night/host rates were determined based on the number of feeding and probing mosquitoes on dogs and humans, respectively. The survival/mortality rates of different species of mosquitoes following the blood meal, and the rate of natural Dirofilaria infection in unfed specimens were estimated. The risk of exposure of dogs and humans to infected mosquito species was determined by combining the bite/host/night and the mosquito infection rates. Results: A total of 1,165 mosquitoes were collected on human (n = 815) and dog (n = 350) baits with varying species composition (i.e., Culex pipiens, 87.3% and Ochlerotatus caspius, 11.6%). Overall, dogs were more attractive to Cx pipiens than humans (feeding rate 70.2% vs probing rate 25.9%). The highest bite/night/host rate was 84.0 for dogs and 26.5 for humans. Cx pipiens displayed a mortality rate of 76.3% within 13 days and Oc. caspius of 100% within two days following the infective blood meal. In addition, D. immitis DNA was detected in unfed Cx pipiens (infection rate of 0.26%-2.07%). The infection rate adjusted for mosquito mortality was 0.38%. Based on data collected, the contact between an infected mosquito and a host can occur as often as every four nights for D. immitis infected-mosquitoes in dogs and within two weeks for humans.

Parasitology Research, 2009

The Central Upper-Rhine (Baden-Württemberg, Germany) is one of the warmest regions in Germany and also harbours abundant numbers of mosquitoes. Case reports on presumably autochthonous occurrence of Dirofilaria spp. were reported previously and were a reason for a further investigation into the occurrence of vector-borne pathogens. For this purpose, 44 hunting dogs from the Central Upper-Rhine region were tested between 4 th and 29 th June 2007. The blood samples were tested using the Knott's test and IDEXX SNAP ® 4Dx ® test. The Knott's test revealed unsheathed microfilaria identified as Dirofilaria repens by PCR in 3 dogs with no history of travelling (6.8 %; 95 % CI: 2.4-18.2 %). The seroprevalence for Anaplasma phagocytophilum was 43.2 % (95 % CI: 29.7-57.8 %), but only 4.5 % (95 % CI: 1.3-15.1 %) for antibodies to Borrelia C 6 peptide. Dirofilaria immitis antigen was not detected in any of the samples. A further 288 blood samples from non-hunting companion dogs of the Central Upper-Rhine region were tested negative for heartworm antigen between February and

Brazilian Journal of Veterinary Medicine

Dirofilaria immitis is a nematode that infects canids worldwide as well as other mammalian species, including humans. Worms and dogs are well adapted to one another, making dogs the best urban host for the parasite. Nevertheless, 30% of dogs do not sufficiently present microfilaremia, that is, the low larval load impairs transmission by mosquitoes and diagnosis by its detection in the blood samples. Therefore, the canine diagnosis must always include a microfilaria test and serological tests to detect adult worm antigens. To describe the clinical findings in naturally infected dogs in Rio de Janeiro, 34 dogs were included in the study. All dogs were evaluated for history, anamnesis, physical examination, complete blood count (CBC), D. immitis testing for antigens (ELISA test SNAP 4Dx Plus®), and microfilarial burden. The most frequent complaint from the owners was coughing (14.7%, 5/34). The most common CBC finding was eosinophilia (29.4%), followed by thrombocytopenia (26.5%) and neutrophilia (14.7%). Of the 34 animals, 91.2% were microfilaremic, with a mean count of 11.939 microfilaria/mL. Veterinarians working in areas endemic to D. immitis should always undergo screening tests and pulmonary auscultation, and increased expiratory sounds, even in the absence of coughing, can be considered a sign of the disease, along with eosinophilia, thrombocytopenia, and neutrophilia.

Frontiers in Veterinary Science, 2020

Background: The cardiopulmonary dirofilariasis caused by Dirofilaria immitis, is a vector-born infection, which can be transmitted to humans. The main host are both domestic and wild canids. It mainly occurs in tropical and subtropical climates, temperature and humidity are the main factors that favor the presence and proliferation of Culicidae mosquitoes. There are few reports of this disease in dogs and humans in Colombia, a region with favorable climatic conditions for the development of this disease. Therefore, this research aimed to study its current prevalence in dogs and the risk of human exposure to the disease in Bucaramanga, one of the most populated areas in Colombia located at the center of the country. Furthermore, its demographic and environmental characteristics could be useful as a study model for other similar locations and neighboring countries. Method: Serum samples from 351 dogs and 506 humans from the Bucaramanga metropolitan area were analyzed. All dog samples were tested with a commercial immunochromatographic test kit to detect the presence of circulating antigens of D. immitis. Human samples were analyzed using a noncommercial ELISA test kit to detect IgG against the somatic antigens of adult D. immitis and Wolbachia. Positive results were further confirmed using a Western blot analysis. Results: Dirofilaria immitis prevalence was 10.82% (95% CI) in dogs and 5.12% (95% CI) in microfilaremic dogs. Seroprevalence in humans was 6.71% (95% CI) and was significantly higher in individuals aged 16-34 years and in women than in men. Conclusions: This study describes seropositivity to D. immitis for the first time in a Colombian human population located in the same area as that of dogs infected with D. immitis, which represents a potential threat to public health. In humans, age and sex can be considered risk factors for exposure to D. immitis. Background Cardiopulmonary dirofilariasis, caused by Dirofilaria immitis, is a vector-borne disease that occurs worldwide, and its main hosts are both domestic and wild canines and felines [1]. Different species of mosquitoes, such as the gender Culex spp., Aedes spp., and Anopheles spp., are involved in the transmission of this parasite. These species represent a constant risk of infection because they feed

Ankara Üniversitesi Veteriner Fakültesi Dergisi, 2013

This study was performed to investigate the prevalence of Dirofilaria immitis in stray dogs with different ages, sexes and breeds. A total of 142 dogs were examined in this study. Blood samples were examined with nativ, modified Knott's and antigen ELISA techniques. Of the total of 142 dogs, 31 were positive for D. immitis with a prevalance value of 22%. In addition 35.5% of positive dogs determine to have occult D. immitis infections. The highest prevalance of D. immitis infections were observed in ≥7 age group (%53,3), and this prevalance was followed by 4-6 (%20,5) and 0.6-3 age group (%17). The difference between ≥7 age group and other age groups (0.6-3 and 4-6 age groups) were found significant (P<0.05), whereas no statistically difference was observed between 0.6-3 and 4-6 age groups (P>0.05). Our results suggest that heartworm treatment and prophylaxis should be considered in Burdur region.

MANTENIMIENTO