Prevalence of dirofilariasis in shepherd and stray dogs in Iranshahr, southeast of Iran

Survey of Common Infectious Diseases in Urban Foxes (Vulpes spp.) in Southeastern Iran

The red fox (Vulpes vulpes) is one of the most common species of wild Canidae and is relatively abundant in Iran. Foxes (Vulpes spp.) transmit many zoonotic diseases, the most important of which are visceral leishmaniasis, rabies, hydatidosis, toxocariasis, and trichinellosis. In this study, visceral leishmaniasis, rabies, ectoparasites, canine gastrointestinal helminths, dermatophytosis, distemper, parvovirus infection, and heartworm infections were evaluated among live-trapped and rescued foxes injured by traffic road accidents referred to the teaching hospital of Kerman, Iran, veterinary faculty. Skin scraping and direct microscopic examination were used to detect ectoparasites and dermatophytosis. Immunochromatography rapid kits were used to detect dirofilariasis, parvovirus infection, and distemper. Necropsy was used to check for gastrointestinal parasites. Rabies and visceral leishmaniosis were screened for with direct fluorescent antibody test and ELISA methods, respectively. Gastrointestinal helminth infections, including Toxocara canis, Taenia taeniaeformis, Dipylidium caninum, Joyeuxiella echinorhyncoids, Toxascaris leonina, Taenia hydatigena, Echinococcus granulosus, Rictolaria spp., Oxynema spp., Macracanthorhynchus hirudinaceus, and Physaloptera spp., were detected. Skin scrapings showed dermatophytosis and various ectoparasites, including Rhipicephalus sanguineus, Ctenocephalides canis and Ctenocephalides felis, and Sarcoptes scabiei, in foxes with dermal lesions. Distemper and parvovirus infection (26.66%) were the common viral diseases, and rabies infection rate was quite high (16.66%). Dirofilariasis and leishmaniasis were detected in 10% of the population. This study showed that urban foxes which often cohabit with humans and domestic animals are carriers of many different pathogens. This interaction may facilitate indirect cross-species transmission of zoonotic disease. Periodic health monitoring and multidisciplinary cooperation for the diagnosis, control, and prevention of these zoonoses is highly recommended.

An updated list of mosquito species in Armenia and Transcaucasian region responsible for Dirofilaria transmission: A review

Canine dirofilariasis is a world-wide distributed mosquito-borne helminthiasis that has a potential zoonotic impact. This disease is a serious problem in Southern Caucasus region, including Armenia. Average extensity of Dirofilaria infection in canids in Armenia is 26.9%. At present, 77 mosquito species (Diptera: Culicidae) are presumed to have a role in the transmission of dirofilariasis. 80 species of Culicidae family mosquitoes are registered in Southern Caucasus Region, and 31 of them are described in Armenia. The following species of Culicidae can serve as vectors of Dirofilaria spp. in Armenia: Aedes vexans, Ae. caspius, Ae. albopictus, Ae. geniculatus, Culex pipiens, Cx. theileri, Cx. modestus, Anopheles maculipennis s.s., An. claviger, An. hyrcanus, An. superpictus, Coquillettidia richardi, Culiseta annulata and Uranotaenia unguiculta. We see a risk of transmission in active foci of dirofilariasis, as well as for human infection in Armenia. Comprehensive research should be conducted on detection of microfilariae in the target mosquito species and in target localities.

The seroprevalence of canine dirofilariosis in dogs in the eastern coastal areas of China

Background and objectives

The present study was carried out to assess the presence of canine Dirofilaria immitis infection in pet dogs in China.

Materials and methods

From October 2018 to November 2019, a total of 216 sera were collected from pet hospitals in Shandong, Jiangsu, Shanghai, Zhejiang, and Fujian regions of Eastern China. The sera were tested by using a commercial canine heartworm antibody ELISA test kit.

Results

70.8% of the pets had significant clinical symptoms resembled to heartworm infection; the overall dirofilariosis positivity found was 12.5% (27/216); Significant positive rates differences were observed between symptomatic and asymptomatic dogs (P < 0.05) (i.e. 15.7% and 4.7% respectively).The prevalence of infection in Shandong Province (15.5%) was the highest among the surveyed areas, but the difference among the geographic regions was not statistically significant (P > 0.05). Furthermore, the prevalence detected in summer (28.2%) was significantly higher than in other seasons (P < 0.05). In addition, no significant difference was observed between male and female sex (P > 0.05).

Conclusions

Altogether, these results suggest that an epidemic of dirofilariosis exists in eastern coastal China, as such preventive measures should be taken to control the spread of dirofilariosis to reduce the risk of human and pet infection with heartworm.

Assessment of the circulation of Dirofilaria immitis in dogs from northern Portugal through combined analysis of antigens, DNA and parasite forms in blood

Dirofilariasis is a vector-borne disease frequent in many countries. Not only infected dogs, but also cats and wild canids (including wolves and foxes), represent important sources of infection for mosquitoes, which are the pathogen vectors. The disease is endemic in Mediterranean countries with increasing incidence in Italy, France, Greece and Spain, but limited epidemiological data is available from Portugal regarding its distribution and impact. Aiming to clarify this, canine whole blood samples (n = 244) from the north of Portugal were tested for Dirofilaria spp. antigens by use of a commercial rapid immunomigration test. Polymerase chain reaction (PCR) and the modified Knott test were also used to assess the presence of microfilariae. Results were also compared to assess the performance of each test used. Of the 244 animals tested, 118 (48.4%) were positive for Dirofilaria immitis (heartworm) in the serological adult worm rapid antigen detection test, and 36 (14.8%) had circulating microfilariae, identified as D. immitis. A combined positivity of 51.6% (126/244) was found. Results indicate that the risk of exposure to D. immitis in dogs is high in this region of Portugal, and that prophylaxis against the parasite is advisable to decrease the occurrence of canine infection and disease. The present study highlights the diagnostic value of serological and molecular tests in determining the prevalence of D. immitis.

A study on canine dirofilariasis in selected areas of Sri Lanka

Objectives

Canine dirofilariasis is a mosquito borne zoonotic filarial parasitic disease caused by Dirofilaria species. In Sri Lanka, human dirofilariasis is endemic and well documented. Even though canine dirofilariasis is an established infection among dog populations in Sri Lanka, the prevalence and risk factors were not documented in Kanthale divisional secretariat, Eastern Province of Sri Lanka. Therefore, the main objective of this study is to determine the prevalence of dirofilariasis and to identify the exposure-related risk factors in dogs using an interviewer administered questionnaire in Kanthale divisional secretariat.

Results

Out of 162 blood samples collected from dogs, 47.5% (n = 77/162) were positive for the presence of microfilariae by direct smear. Of 162 samples 58.6% (n = 95/162) were molecularly identified as D. repens. Species-specific primer pair DIR3/DIR4 that amplified 5S rRNA was used. The current study observed a significant association between mongrels and canine dirofilariasis (p = 0.049), where 61.3% (n = 95) out of 155 mongrels showed PCR positivity. This study showed no significant association between the occurrence of dirofilariasis and the age, sex, rearing method, presence or absence of skin rash, and stray or domestic dogs. Dirofilaria immitis was not identified in direct smear test and PCR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06024-0.

Canine microfilaraemia in some regions of Iran

BACKGROUND

Dirofilaria immitis and Dirofilaria repens are vector-borne zoonotic parasites which affect mainly dogs and humans worldwide. In Iran, information about the distribution of those nematodes is scant in several regions. Therefore, we investigated the prevalence of these filarial parasites in stray dogs from five Iranian provinces where no information about these parasites is available.

METHODS

Blood samples were collected from 344 stray dogs in five provinces of Iran (i.e. Mazandaran, Gilan, Esfahan, Qazvin and Loresan). The presence of microfilariae was assessed using direct smear, modified Knott's test, molecular detection of filarial DNA (cox1 gene) and Wolbachia endosymbiont of parasitic nematodes (ftsZ gene) by conventional PCR (cPCR). All of the PCR products were sequenced and phylogenetic analysis was performed.

RESULTS

In total, 75 dogs (21.8%) were found to be positive for D. immitis by cPCR. Infection was detected in all provinces, with the highest prevalence in Gilan province (22/28; 78.6%). Acanthocheilonema reconditum was diagnosed in five dogs (1.4%) from three provinces (i.e. Esfahan, Mazandaran, Gilan). Two dogs were infected with both parasites and three were only infected with A. reconditum. Dirofilaria repens infection was not found in the examined population. Representative sequences of the D. immitis cox1 gene from dogs from the northern provinces (Mazandaran, Gilan, Qazvin) were grouped together and distinctly separate from the ones from western and central provinces (Lorestan and Esfahan), suggesting that different nematode populations are present in the country.

CONCLUSION

The data reported herein fill existing gaps in knowledge about canine filarial infection in two Iranian provinces and record the highest prevalence of D. immitis ever reported in the country (i.e. 78.6%). A geographical review of the literature about Dirofilaria spp. and A. reconditum infections in dogs and humans has also been summarized, indicating that D. immitis and D. repens are distributed in 22 of 31 provinces in Iran, whereas A. reconditum is present in fewer regions. Effective control strategies are advocated for owned dogs, and a national program for the management of stray dogs is needed to minimize the risk of infection in animals and humans.

An Accessible Alternative to Melarsomine: "Moxi-Doxy" for Treatment of Adult Heartworm Infection in Dogs

Canine heartworm infection, caused by the filarial parasite Dirofilaria immitis, represents a serious and expanding animal welfare concern that is expected to increase due to the effects of climate change and the COVID-19 pandemic. A body of evidence has emerged to support the use of a non-arsenical adulticide treatment protocol, using moxidectin and doxycycline to kill adult heartworms over a prolonged period. While a three-dose protocol using the arsenical drug melarsomine is currently the safest and most effective treatment for heartworm infection, this drug is not available in some countries and is inaccessible for many owners and animal shelters. Moxidectin-doxycycline (moxi-doxy) provides a viable alternative to no treatment at all, in cases where arsenical treatment is not possible. Based on current evidence, the most effective non-arsenical treatment regimen is doxycycline 10 mg/kg PO q 12 or 24 h for 28 days, combined with topical moxidectin at label dose. Moxidectin is repeated monthly until no antigen detected (NAD) status is confirmed. Sustained release injectable moxidectin, in combination with doxycycline, may provide an alternative in remote regions or in settings where significant compliance or accessibility concerns exist, but more studies are needed. In moxi-doxy protocols, doxycycline should be repeated annually until NAD. This review summarizes the safety and efficacy of moxi-doxy, addresses controversies surrounding this treatment approach, and provides detailed recommendations for treatment regimens and post-treatment testing.

Trypanosoma cruzi co-infections with other vector borne diseases are frequent in dogs from the pacific coast of Ecuador

Dogs are a reservoir for Chagas disease, caused by Trypanosoma cruzi (T. cruzi), and other companion vector-borne diseases, including ehrlichiosis (Ehrlichia canis and Ehrlichia ewingii), anaplasmosis (Anaplasma phagocytophilum and Anaplasma platys), dirofilariasis (Dirofilaria immitis) and Lyme disease (Borrelia burgdorferi). This study has two key objectives: 1) to determine seroreactivity against T. cruzi in dogs from the town of Colón, in Portoviejo city, in the central coast of Ecuador; and 2) to establish the coinfection frequency of other companion vector-borne diseases in dogs positive for T. cruzi. Antibodies against T. cruzi were detected using two enzyme-linked immunosorbent assays. Diagnostic consensus between ELISA tests was established using the Cohen's Kappa coefficient. Other haemoparasitic diseases were detected using the IDEXX SNAP® 4Dx® kit in dogs previously diagnosed as T. cruzi-seropositive. From 84 dogs sampled, 57.14% (48/84) tested positive for T. cruzi. Co-infection analysis of 25 dogs positive for T. cruzi revealed antibodies also against Ehrlichia spp. (48%), Anaplasma spp. (28%), and Dirofilaria immitis (12%). These results provide a novel perspective regarding the status of these pathogens which co-infect dogs in Colón. Since all these pathogens are zoonotic, our findings should warn regional health authorities to implement sanitary programs, to better prevent and control vectors associated to these pathogens. On the other hand, human and veterinarian doctors, should consider that patients with a cardiac infection condition could be suffering co-infections with two or more vector transmitted pathogens.

Dirofilariosis caused by Dirofilaria immitis in the south of Kerman province, Iran

BACKGROUND

Dirofilariosis due to Dirofilaria immitis is endemic in various areas of Iran. Domestic dogs are the main reservoirs and represent a major potential infection source for the vector and humans.

OBJECTIVE

This study aimed to explore the prevalence of dirofilariosis due to D.immitis and its public health importance in domestic dogs in the Jiroft district, south of Kerman province, Iran, by serological and parasitological methods.

METHODS

This descriptive study was carried out as a cross-sectional investigation. A questionnaire was completed for 100 domestic dogs from May 2017 to February 2018 and recorded their age, sex, and clinical features. Also, we used enzyme-linked immunosorbent assay (ELISA) to identify antigens of heartworms in the bloodstream, with 98% sensitivity and 100% specificity, and parasitological techniques (Knott's test) to detect microfilariae in canine blood in Jiroft district, south of Kerman province, Iran.

RESULTS

Overall, 10 (10%) and 4 (4%) domestic dogs were infected as confirmed by ELISA and modified Knott's tests, respectively. The rate of occult infections in the ELISA test than Knott's test was 60%. No significant difference was found between dirofilariosis and gender. In contrast, there was a significant difference between dirofilariosis infection and age (P < 0.05).

CONCLUSION

The present findings could help understand the epidemiological aspects of D. immitis for future control programs and take appropriate preventive and therapeutic strategies against the disease.

Prevalence of Dirofilaria immitis in shelter dogs in Bucaramanga metropolitan area, Colombia

The heartworm Dirofilaria immitis is the causative agent of cardiopulmonary dirofilariosis in dogs and cats and also infects humans. The current knowledge about this parasite in South America is scarce compared to North America and Europe. Nevertheless, this parasite has been reported in some regions of Colombia. The objective of this study was to determine the prevalence and risk factors associated with D. immitis infection in shelter dogs from Bucaramanga metropolitan area. We performed a cross-sectional study using blood samples from shelter dogs. Microfilariae testing of whole blood included a blood smear and modified Knott's test. Antigen testing of serum was performed using the Anigen Rapid HW Ag Test Kit 2.0 ®. A descriptive analysis and univariable logistic regression analysis were applied. A total of 207 whole blood samples, from 7 shelters dogs in the Bucaramanga metropolitan area, were utilized. The overall prevalence of D. immitis observed in shelter dogs in the Bucaramanga metropolitan area by blood smears and modified Knott's test was 6.3% (13/ 207) and 0.5% (1/207) by immunochromatography test kit. Regarding the prevalence by municipalities, there was a statistical association (P < .05), indicating that the prevalence was higher in dogs in Girón municipality. Likewise, there was a statistical association (P < .05) between the prevalence with respect to heartworm knowledge and mosquito control. For prevalence by gender, age group, dog breed, and hair length, there was no statistical association (P > .05). For Girón municipality there was a 7.1 times (OR = 7.1; CI95% 0.8-59.2; P < .05) increased infection risk. This study provides current data and the first known report of the prevalence of D. immitis microfilaremia and antigenemia in shelter dogs in the Bucaramanga metropolitan area, and these results could be useful for designing new control measures for this infection. We observed that the prevalence of both microfilaremia and antigenemia was significantly lower in these sampled dogs compared to previous reports.

Seroprevalence of Neospora caninum Infection in Dog Population Worldwide: A Systematic Review and Meta-analysis

PURPOSE

Neospora caninum is an obligate intracellular apicomplexan protozoan that causes neurological disorders in dogs. This systematic review and meta-analysis targeted at evaluating the worldwide seroprevalence rate of N. caninum in dogs.

METHODS

Five electronic databases, including PubMed, Scopus, Web of Science, Science Direct, and Google Scholar, until December 2018 were thoroughly searched for relevant English language articles. Papers were selected based on inclusion criteria. Data were analyzed in StatsDirect statistical software (version 2.7.9).

RESULTS

The searching process yielded a total number of 156 papers. The total prevalence (95% confidence intervals) of N. caninum infection in dog population worldwide was measured as 17.14% in data analyses (15.25-19.10). In addition, a significant association was also detected between neosporosis infection in dogs and continent, country, year, WHO regions, sample size and diagnostic method (P < 0.001).

CONCLUSION

Dogs are a matter of concern to public health officials as a source of N. caninum infection. Therefore, it is of paramount importance to provide comprehensive data and systematically analyze the prevalence of N. caninum infection in dogs. Accordingly, it is recommended that researchers carry out further studies to prevent and control neosporosis among dog population worldwide.

The global status of Dirofilaria immitis in dogs: a systematic review and meta-analysis based on published articles

Dirofilaria immitis is a parasitic filarial nematode responsible for heartworm disease in domestic as well as wild canines and felines and pulmonary or cutaneous infections in humans. This systematic review and meta-analysis aimed to evaluate the status of D. immitis in dogs based on available literature. Four English language databases (ISI Web of Science, Scopus, PubMed and Science Direct) containing data on D. immitis prevalence in dogs were thoroughly searched resulting in the inclusion of 193 studies. The findings revealed that the pooled and weighted prevalence of D. immitis infection in dog population based on published papers throughout the world was 10.91% (95% CI=10.18-11.65). In addition, subgroup analysis based on meta-regression revealed that a significant difference between the pooled and weighted prevalence of D. immitis in dogs and country (β =0.14, P=0.049). Given the relatively high prevalence of D. immitis infection in dogs and its adverse effects, it is suggested that to perform more research on the prevention and control of dirofilariasis infection in dogs worldwide.

Filarial worms: a systematic review and meta-analysis of diversity in animals from Iran with emphasis on human cases

Current systematic review and meta-analysis demonstrate the prevalence reports of filariasis in animals in Iran along with human cases. Studies were screened, relevant papers were selected and the random-effect model was used by forest plot with 95% confidence interval (CI). Of 17 records of human case-reports, particularly from Khuzestan province (5 cases), Dirofilaria repens was the most detected parasite (10 cases) with higher involvement of the right eye (7 cases) than other organs. Eleven animal species were reported to be parasitised by filarioids in Iran. The prevalence of Dirofilaria immitis in canids was 14.69% (95% CI: 10.33-19.67), with highest rates (20.92%; 95% CI: 13.84-29.03) in free-ranging dogs. Male (10.07%; 95% CI: 5.10-16.47) and more than 1-year old (20.77%; 95% CI: 8.66-36.42) dogs were more likely to be found infected. The frequency of other filarioids of zoonotic interest was: Acanthocheilonema reconditum in dogs 2.15% (95% CI: 0.71-4.33), Dipetalonema evansi in camels 10.16% (95% CI: 4.73-17.34), Onchocerca cervicalis in horses 3.63% (95% CI: 1.44-6.75%) and Onchocerca fasciata 16.57% (95% CI: 10.12-24.24%) in camels. Still, our knowledge on parasitic filariae in Iran is limited and more investigation is needed in both human and animal populations.