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Parasites & Vectors Oct 2020Dirofilaria immitis is responsible for heartworm disease in dogs in endemic areas worldwide. Screening for this infection is done by blood tests. Antigen testing is the...
BACKGROUND
Dirofilaria immitis is responsible for heartworm disease in dogs in endemic areas worldwide. Screening for this infection is done by blood tests. Antigen testing is the most sensitive method to detect an infection with adult (female) worms. Microscopic examination of a blood smear or Knott's test can be used to detect circulating microfilariae, the infective larvae. To increase the sensitivity of the antigen test by decreasing the false negative test results, heating of the blood sample has been recommended in recent guidelines. Heating is believed to remove blocking immune-complexes. Circulating microfilariae are not specific findings for heartworm infection, as other nematodes (among others, Acanthocheilonema dracunculoides) can also result in microfilaremia. Although the type of microfilariae cannot be determined by microscopy alone, real-time PCR can reliably identify the infecting nematode species. Correct identification of the parasite is of major importance, as an infection with D. immitis requires antiparasitic therapy, whereas A. dracunculoides is thought to be a clinically irrelevant coincidental finding. The present case report describes a microfilaremic dog where the initial antigen test for D. immitis turned positive after heat treatment, whereas real-time PCR revealed that the microfilariae were A. dracunculoides (syn. Dipetalonema dracunculoides).
RESULTS
A circa 5-year old, asymptomatic Spanish mastiff dog was referred for heartworm therapy because microfilariae were found via a screening blood test. The dog was recently imported to the Netherlands from Spain, where it had been a stray dog. Antigen tests on a plasma sample for D. immitis were performed with three different test kits, which all turned out to be negative. However, heat treatment of two of these samples were carried out and both of them led to a positive antigen test result. Real-time PCR showed that the circulating microfilariae belonged to A. dracunculoides species. Three administrations of moxidectin spot-on at monthly intervals resulted in a negative antigen and a negative Knott's tests one month after the last treatment.
CONCLUSIONS
We conclude that heat treatment of initially negative blood samples for D. immitis could lead to false positive antigen test results if the dog is infected with A. dracunculoides.
Topics: Acanthocheilonema; Acanthocheilonemiasis; Animals; Antigens, Helminth; Blood; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; False Positive Reactions; Female; Hot Temperature; Immunologic Tests; Microfilariae
PubMed: 33004047
DOI: 10.1186/s13071-020-04376-9 -
Pathogens (Basel, Switzerland) Jul 2020Previous studies have reported filarial parasites of the genus and from French Guiana monkeys, based on morphological taxonomy. In this study, we screened blood...
Previous studies have reported filarial parasites of the genus and from French Guiana monkeys, based on morphological taxonomy. In this study, we screened blood samples from nine howler monkeys () for the presence of filaria and DNA. The infection rates were 88.9% for filaria and 55.6% for wolbachiae. The molecular characterization, based on the gene of filariids, revealed that are infected with at least three species ( sp., sp. and an unidentified Onchocercidae species.). Since the and generic primers are not very effective at resolving co-infections, we developed ITS genus-specific PCRs for and genus. The results revealed coinfections in 75% of positives. The presence of sp. and sp. was also confirmed by the phylogenetic analysis of their associated . sp., which close to the species from the subgenus encountered in New World Monkeys, while sp. was identical to the strain circulating in French Guiana dogs. We propose a novel genus-specific qPCR. We applied it to screen for infection in howler monkeys and 66.7% were found to be positive. Our finding highlights the need for further studies to clarify the species diversity of neotropics monkeys by combining molecular and morphological features. The novel genus-specific qPCR assays could be an effective tool for the surveillance and characterization of this potential zoonosis.
PubMed: 32752052
DOI: 10.3390/pathogens9080626 -
Parasitology Aug 2020Current systematic review and meta-analysis demonstrate the prevalence reports of filariasis in animals in Iran along with human cases. Studies were screened, relevant... (Meta-Analysis)
Meta-Analysis
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.
Topics: Animals; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Filariasis; Filarioidea; Humans; Iran
PubMed: 32249728
DOI: 10.1017/S003118202000058X -
Journal of Parasitic Diseases :... Dec 2019The prevalence and species spectrum of some blood and intestinal parasites affecting imported camels was studied on a total of 120 clinically suspected camels (males)...
The prevalence and species spectrum of some blood and intestinal parasites affecting imported camels was studied on a total of 120 clinically suspected camels (males) imported to Egypt from Sudan during the period from January till July 2016 in Abu-Simbel quarantine station, Aswan governorate. Blood and fecal samples were collected from all camels under the study. The fecal samples were collected and examined by sedimentation-floatation techniques for detection of parasitic eggs/oocysts. Coprological examination revealed that the prevalence rate of the parasitic infection was 60% (72 out of 120). Eighteen species of helminthes/protozoan parasites eggs/oocysts were encountered stongyles species were the hightest prevalent of nematodes 12.5%. Four genera of flat worms were identified in the present study including sp. 0.8%, sp. 3.3%, sp. 7.5% and sp. 0.8%. Four species of were identified (, , and ) in infected camels the commenst one is 15.8%, sp. and were recorded with a prevalence rate about 15.8%, 8.3% and 6.7% respectively. Blood smears from jugular vein revealed that 2.5% of camels were infected with Wide spectrum and high prevalence of internal parasites were observed in the present study which may be lead to severe economic losses, so the application of control measures and treatment of infected camels with specific and effective drugs during the quarantine period are most important to prevent spreading of parasitic infestation and/or introduction of parasites previously not exist in our country.
PubMed: 31749532
DOI: 10.1007/s12639-019-01138-y