Dirofilariasis In Dogs Research Articles

Prevalence and risk factors associated with Dirofilaria immitis infection in dogs in Makurdi, Benue State, Nigeria

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±60.81x109/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.

No evidence of Dirofilaria repens infection in red foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides) from Brandenburg, Germany.

Dirofilaria (D.) repens is a nematode causing dirofilariasis in dogs, cats and in humans. Red foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides) are well-known wildlife reservoirs for zoonotic diseases. These two species are highly abundant in Germany, frequently exposed to vector mosquitoes and potentially susceptible to Dirofilaria infections. To obtain data about D. repens infections in these animals, red fox and raccoon dog carcasses (hunted or found dead) were collected from January to September 2009 in the Federal State of Brandenburg, Germany. Lung tissue samples were subjected to DNA extraction and examined for the presence of Dirofilaria DNA by means of D. repens-specific PCR. D. repens-specific DNA could not be amplified from the lungs of red foxes (n = 122; 0%) nor from the lungs of raccoon dogs (n = 13; 0%), suggesting a limited role if a role at all in the natural transmission cycle of D. repens in Brandenburg.

Detection of Dirofilaria immitis DNA in host serum by nested PCR.

The heartworm Dirofilaria immitis is the causative agent of dirofilariasis in dogs. Studies have shown that parasite-derived cell-free DNA (cfDNA) can be detected in host blood and may be a promising diagnostic marker for parasitic infections. Thus, our aim was to detect D. immitis-derived cfDNA in host serum by nested PCR. Sera were collected from 12 dogs with natural D. immitis infections; eight were microfilaria (mf)-positive, and the remaining four were mf-negative. Culture fluids derived from single-sex adult D. immitis worms (mf-producing females and males) were also tested for cfDNA. All mf-positive sera were positive by nested PCR, whereas no amplification products were detected in mf-negative sera. The culture fluid of mf-producing females was positive by nested PCR but that of males was negative. All products amplified by nested PCR were sequenced to confirm that the amplicons were those of D. immitis. These results indicate that D. immitis DNA circulates freely in dog serum, except in mf-negative dogs. Additionally, D. immitis cfDNA may primarily be derived from the mf, and adult worms appeared to be minor contributors of cfDNA concentrations in serum; however, the contribution of D. immitis cfDNA derived from larvae of other developmental stages is unclear. An evaluation of the kinetics of D. immitis cfDNA in host serum throughout the parasite life cycle could facilitate the development of early molecular diagnostic techniques. To the best of our knowledge, this is the first report of the detection of mitochondrial DNA from a filarial parasite in host serum.

Dirofilariasis - an emergent human parasitosis in Romania.

Changing vector habitats due to climate change increase the risk of less common vector-borne diseases spreading to temperate areas. An example of such a disease is dirofilariasis. The present article is a case presentation of ocular dirofilariasis. The peculiarities of this case and its implications to public health are presented herein, in addition to a literature review of the epidemiological data regarding dirofilariasis in dogs and humans. A16-year-old adolescent, who had never travelled outside Galaţi County, was admitted to the hospital's pediatric department with conjunctival edema, foreign body perception, redness and local pain in the left eye. A parasitological exam identified Dirofilaria repens. The outcome of the condition was favorable. Although canine dirofilariasis is more often encountered by veterinary practices, only few human cases had hither to been reported in Romania, none in Galaţi County. A national Romanian prevalence study on dirofilariasis in animals is called for in order to improve the management of the disease, both in veterinary and human medicine.

Subconjunctival Dirofilaria Repens

Summary Dirofilariasis is a relatively rare zoonotic disease that affects mainly dogs. The two most common representatives are Dirofilaria immitis and Dirofilaria nochtiella. Studies have documented the spread of the disease across Central and Eastern Europe in recent years due to global changes. In Bulgaria since 2001 there are around 20 cases of dirofilariasis in dogs registered yearly. We report a case of subconjuctival dirofilariasis in a 47-year-old woman living in Southwestern Bulgaria. The infection manifested as a painful, inflamed nodule in the left eye, containing a vital parasite. Morphological analysis aroused suspicion for a filarial worm belonging to the genus Dirofilaria. Subsequent analysis confirmed suspicions and identified the parasite as Dirofilaria repens. After removal, the subconjunctival nodule completely resolved and the patient was successfully cured.

Identificación morfológica y molecular de filarías caninas en una comuna semi-rural de la Región Metropolitana, Chile

To date, there has been no definitive confirmation of the presence of zoonotic dirofilariasis in dogs in Chile. To study the presence of dirofilarias in blood samples from dogs collected in a semi-rural district near Santiago and to compare their frequency in dogs with and without dermatological manifestations. We examined 100 blood samples for dog filariae infections using microscopic methods (modified Knott technique). 50 dogs presented dermatological symptoms or signs compatible with filarial infections and 50 were asymptomatic. ITS-2 and 12s rDNA gene amplification by PCR and sequencing were performed in samples microscopically positive for microfilariae. Results. We observed microfilariae in 22 dogs (22%). Of these, 16/50 (32%) were symptomatic and 6/50 (12%) were asymptomatic (p = 0.02). Morphologically, the majority of micro-filariae were similar to Dirofilaria repens, although many had a bigger size than previously described. Nucleotide sequencing of the amplified genes showed no more than 95% homology with the D. repens sequences available for comparison. D. reconditum and D. dracunculoides infections were also identified. These features might indicate the presence of new species of Dirofilaria or a D. repens close related variant in Chile.

Heartworm Disease (Dirofilaria immitis) and Their Vectors in Europe - New Distribution Trends.

Cardiopulmonary dirofilariasis is a cosmopolitan disease caused by Dirofilaria immitis, which affects mainly canids and felids. Moreover, it causes zoonotic infections, producing pulmonary dirofilariasis in humans. Heartworm disease is a vector-borne transmitted disease, thus transmission depends on the presence of competent mosquito species, which is directly related to favorable climate conditions for its development and survival. Cardiopulmonary dirofilariasis is mainly located in countries with temperate and tropical climates. Europe is one of the continents where animal dirofilariasis has been studied more extensively. In this article we review the current prevalence of canine and feline cardiopulmonary dirofilariasis in the European continent, the transmission vectors, the current changes in the distribution and the possible causes, though the analysis of the epidemiological studies carried out until 2001 and between 2002 and 2011. The highest prevalences have been observed in the southern European countries, which are considered historically endemic/hyperendemic countries. Studies carried out in the last 10 years suggest an expansion of cardiopulmonary dirofilariasis in dogs toward central and northern Europe. Several factors can exert an influence on the spreading of the disease, such as movement of infected animals, the introduction of new species of mosquitoes able to act as vectors, the climate change caused by the global warming, and development of human activity in new areas. Veterinary controls to prevent the spreading of this disease, programs of control of vectors, and adequate protocols of prevention of dirofilariasis in the susceptible species should be carried out.

Seroprevalence of Dirofilaria immitis, feline leukemia virus, and feline immunodeficiency virus infection among dogs and cats exported from the 2005 Gulf Coast hurricane disaster area

To determine seroprevalence of dirofilariasis in dogs and seroprevalences of dirofilariasis, FeLV infection, and FIV infection in cats exported from the Gulf Coast region following the 2005 hurricanes. Seroprevalence survey. 1,958 dogs and 1,289 cats exported from Louisiana, Mississippi, and Texas between August 20 and December 31, 2005. 141 animal welfare groups in 37 states and Alberta, Canada, reported results of serologic testing. Risk factors for infection, including age, sex, neuter status, breed, and state of rescue, were examined by means of univariate and multivariate logistic regression. Seroprevalence of dirofilariasis in dogs was 48.8%. Sexually intact dogs were 1.6 times as likely to have dirofilariasis as were neutered dogs, dogs in the ancient breed group were 2.2 times as likely and dogs in the guarding breed group were 1.7 times as likely to have dirofilariasis as were dogs in the herding breed group, and dogs from Mississippi were significantly less likely to have dirofilariasis than were dogs from Texas. Seroprevalences of dirofilariasis, FeLV infection, and FIV infection in cats were 4.0%, 2.6%, and 3.6%, respectively. Seroprevalence of FIV infection was significantly higher in adult cats than in juveniles and in males than in females. Results suggest that dogs and cats exported from the 2005 Gulf Coast hurricane disaster area had disease rates similar to those for animals in the region prior to the hurricanes.

Dirofilaria repens: Cloning and Characterization of a Repeated DNA Sequence for the Diagnosis of Dirofilariasis in Dogs, Canis familiaris

A highly repetitive DNA element from the genome of the filarial nematode Dirofilaria repens has been cloned and sequenced. The 176-base pair repeating units are arranged in direct tandem and are clustered in the parasite genome. All repeats appear to belong to a single family although some elements have diverged significantly. The repeats are present in about 15,000 copies and constitute approximately 3.0% of the parasite genome. The cloned repetitive sequence hybridized only to D. repens DNA and was sensitive enough to detect 250 to 500 pg of D. repens DNA, a single microfilariae in infected blood samples, and a single third stage larvae in mosquitoes. The high specificity and sensitivity of the cloned fragment makes it ideal as a diagnostic probe for detecting D. repens in both the host and the vector.

Diagnóstico de dirofilariose oculta pelo teste de ELISA, em cães do Estado de São Paulo

A dirofilariose oculta constitui-se num grande problema diagnóstico e pode estar relacionada a: a) infecções pré-patentes; b) infecções causadas por vermes de um único sexo; c) esterilidade dos parasitas devido à idade ou induzida por ação de drogas; d) resposta imune mediada. Avaliou-se, no presente trabalho, a prevalência de dirofilariose em cães do Estado de São Paulo, através do teste de ELISA (CITER Semi-Quant TM Canine Heartworm Antigen Test Kit), bem como se tentou caracterizar a causa da ausência de microfilaremia circulante, com auxílio de exames subsidiários. De 244 soros examinados, 35 (14,34%) mostraram-se positivos. Destes, 20 apresentaram, além do teste de ELISA positivo, una ou mais alterações (radiográficas /eletrocardiográficas), compatíveis com o diagnóstico de dirofilariose canina; e, nos demais 15 animais, assintomáticos, também soropositivos pelo teste de ELISA, descartou-se a forma de infecção prépatente, pois haviam sido expostos ao risco da infecção há mais de 6 meses, e também a esterilidade dos parasitas conseqüentemente à ação de drogas.

An overview of serological tests currently available for laboratory diagnosis of parasitic infections

Current methods and commercial test systems for the diagnosis of parasitic infections in both animals and humans are reviewed. Lists of test kits and their manufacturers are provided along with ordering information: the only commercially available test kits are for the diagnosis of toxoplasmosis in humans or animals and dirofilariasis (heartworm) in dogs. A partial list of diagnostic laboratories and the parasite tests they perform is also provided. Complete lists of diagnostic tests that could be obtained in the private sector are not available but would be useful. Two microfluorometric solid-phase assay systems are reviewed, and adaptations to custom assays for several kinds of parasites are briefly described. User problems in performing tests and interpreting results are stressed with emphasis placed on diagnosis of dirofilariasis in dogs. False-positive serology in dogs without heartworms and negative antibody reponses in micro-filariae-positive animals are discussed with respect to proper interpretation of results.

STUDIES ON THE TREAMENT OF <i>MICROFILARIA IMMITIS</i> INEECTION BY INTRAVENOUS INJECTION OF NATRIUM ANTIMONYL TARTARATE

In view of the literatures regarding the treatment of microfilaria infection in man and dogs, we know that almost all anthelmintics, for instance, atoxyl, salvarsan, imamicoll, phenocoll, trypanred, ttypanblue, malachitgreen, methylenblue, emetin, picric acid, filarisin chinine hydrochlolide, etc. have hitherto been used without any favorable effects.On the contrary, a number of reports as regards the favorable effects of intravenous injections of tartar emetics, especially natrium antimonyl tartarate upon schistosomiasis, paragonimiasis, and chlonorchiasis has recently been published by various authors.Referring to these reports, we engaged in the treatment of Dirofilariasis in dogs which is widely spread in Japan by employing natrium antimonyl tartarate for the past several years. In the present paper the results obtained are briefly described.Periodicity of Microfilaria Immitis. In order to count the number of microfilariae per 20cmm. of the blood collected from the peripherial veins of four filarial dogs was examined every three hours for twenty-four hours, that is, from the 20th to the 21st of March in 1923. The results are shown as follows (Table 1):So far as any conclusion can be drawn from these few observations, it would appear that Microfilaria immitis has a slight periodicity in the blood of peripheral veins. The maximum number was observed at six o'clock in the evening, but it was not so marked as in the case of embryos of Wuchereria bancrofti. Based upon this fact we procured the blood in the evening for the purpose of counting of microfilariae in it with possible certainty.Dose of Natrium Antimonyl Tartarate Required. The solution of natrium antimonyl tartarate employed was freshly prepared before use in a concentration of 0.003 or 0.004 per each cubic centimeter of the physiological saline solution.Prior to treating filarial dogs, a series of experiments were carried out mainly on puppies to determine the safe dose of the drug for healthy dogs. The results are given in Table II.From the foregoing experiments it has been noticed that the death of the animals actually followed the administration of a single dose at the rate of 0.01 per kilo of the body weight within twenty-four hours if an after-treatment such as the administration of adrenalin was not carried out, and that seven doses at the rate of 0.005 per kilo for successive days would cause the toxic ill-effects in healthy dogs. Two dogs could tolerate the daily administration of seven doses of 0.004 per kilo, while four injections of 0.004 per kilo resulted in some cases in death of the animals, These conflicting results suggest that all dogs are not equally susceptible to the drug.Generally speaking, definite proof has been obtained that the several intravenous injections of natrium antimonyl tartarate in doses varying from 0.003 to 0.004 per kilo at intervals of one to two days could be carried out in the non-filarial dogs without any deleterious effects.In the following experiments, we administered the same amounts of the drug in the same way to six filarial dogs to obtain information as to the anthelmintic dose and the resistance of dogs against the drug, and obtained the result that the administration of only three doses at the rate of 0.003 per kilo at one to five day intervals was sufficient to kill microfilariae in the peripheral blood as in the case of dog No 4. It will be obtained, however, that the same dose of the drug had not always lethal effect on filarial embryos. In most cases, slight or severe toxic symptoms such as refusal to take food, elevation of the bodily temperature, drowsiness, sometimes even collapse for a few days, followed the practice. The details are given in Table III.After these experiments, the injections of natrium antimonyl tartarate were carried on seventeen patients for the treatment of microfilaria injection with satisfactory results.