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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 Research Apr 2020At least two species of filarial worms, Dirofilaria immitis and Acanthocheilonema (Dipetalonema) odendhali, infect otariid pinnipeds, including the California sea lion...
At least two species of filarial worms, Dirofilaria immitis and Acanthocheilonema (Dipetalonema) odendhali, infect otariid pinnipeds, including the California sea lion (Zalophus californianus). To date, evidence of infection in sea lions has come from dead or captive animals, and little is known about filariasis in free-living populations. We sampled 45 California sea lion adults and 197 pups captured at 12 rookeries from different ecological regions within the Gulf of California and detected and quantified D. immitis and A. odendhali microfilariae in blood smears. We investigated differences in prevalence and parasite load (intensity of infection) among ecological regions. Microfilariae were detected in the blood of 35 of the 45 (77.78%) adult females and in 1 of the 197 (0.51%) pups examined. The average burden of A. odendhali per microlitre of blood was nearly twice that of D. immitis. Prevalence and intensity of infection differed significantly among regions, being highest for colonies within the northern and northcentral regions and lowest in the southern region. Dirofilaria immitis and A. odendhali infections displayed a similar spatial pattern of prevalence. Colony density inversely predicted the prevalence of microfilariae. Based on the clinical parameters typically associated with filarial infections in carnivores and physical examinations, none of the sea lions appeared to have evidence of disease. This is a first approximation to investigate the prevalence of microfilaria infections in free-ranging California sea lions and to explore their relevance to population health.
Topics: Acanthocheilonema; Acanthocheilonemiasis; Animals; California; Dirofilaria immitis; Dirofilariasis; Female; Mexico; Parasite Load; Sea Lions
PubMed: 32166425
DOI: 10.1007/s00436-020-06638-y -
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 -
Systematic Parasitology Mar 2019Although little studied, infections with nematodes of the Onchocercidae Leiper, 1911, predominated by the genera Dipetalonema Diesing, 1861 and Mansonella Faust, 1929,...
Although little studied, infections with nematodes of the Onchocercidae Leiper, 1911, predominated by the genera Dipetalonema Diesing, 1861 and Mansonella Faust, 1929, are frequent in wild primates and human populations in the Neotropical forest areas. This study reports natural infections with Dipetalonema freitasi Bain, Diagne & Muller, 1987 and D. gracile (Rudolphi, 1809) in two free-living species of pitheciid primates, extending the known geographical distribution of these species to the forest of the Peruvian Amazon. Adult worms were recovered from the thoracic and abdominal cavities of two species of monkeys, Pithecia monachus monachus (É. Geoffroy Saint-Hilaire) and Cacajao calvus ucayalii (Thomas) (Primates: Pitheciidae), collected along the Yavari-Mirin River basin and analysed via light and scanning electron microscopy. Both host species represent new host records for D. freitasi and D. gracile. Morphometric data are also presented for the sampled filarial worms in addition to morphological details obtained through light and electron microscopy examination of D. freitasi specimens.
Topics: Abdominal Cavity; Animals; Microscopy, Electron, Scanning; Nematoda; Pitheciidae; Species Specificity; Thoracic Cavity
PubMed: 30747402
DOI: 10.1007/s11230-019-09838-y -
Veterinary World Nov 2018The present investigation was conducted to study the prevalence of microfilaremia in dogs in Gujarat.
AIM
The present investigation was conducted to study the prevalence of microfilaremia in dogs in Gujarat.
MATERIALS AND METHODS
A total of 418 adult dogs aged between 2 and 14 years with signs of weakness and non-specified complaints, presented at TVCC, Deesa (North Gujarat), Nandini Veterinary Hospital, Surat (South Gujarat), and Private Clinics, Ahmedabad (Central Gujarat), were included in the present investigation for studying the prevalence of microfilaremia from July 2016 to May 2017.
RESULTS
A total of 418 dogs were screened, of which 33 were found positive for circulating microfilariae with the prevalence rate of 7.89% in the population. Among microfilaremic dogs, the finding of microfilariae of () reconditum was more common (23 cases; 69.69%) than (10 cases; 30.30%) making their prevalence in the population of 418 dogs as 5.50% and 2.39%, respectively. Breed-wise distribution of microfilaremic dogs revealed that 12 (36.36%), 8 (24.24%), 5 (15.15%), 4 (12.12%), 2 (6.06%), 1 (3.03%), and 1 (3.03%) cases were observed in Pomeranian, non-descript, German Shepherd, Labrador, Great Dane, Lhasa Apso, and Pug dogs, respectively. Of 10 cases of , 5, 2, 2, and 1 were observed in Pomeranian, Labrador, non-descript, and Great Dane dogs, respectively. Cases of were highest in Pomeranian (7), followed by non-descript (6), German Shepherd (5), Labrador (2), Great Dane (1), Lhasa Apso (1), and Pug (1). Age-wise distribution recorded significantly (p≤0.01) higher number of cases in adult dogs (4-14 years) for (30.30%) and (39.39%). Sex-wise distribution of microfilaremic dogs showed that male (22/33, 66.66%) was more predisposed to microfilaremia rather than females (11/33, 33.34%). It is apparent from the study that the number of dogs with microfilaremia due to was significantly (p≤0.01) higher than that of .
CONCLUSION
The present study revealed that microfilaremia due to and is prevalent in the state of Gujarat. The infection with was associated with severe lung and cardiac pathological manifestations.
PubMed: 30587889
DOI: 10.14202/vetworld.2018.1564-1568 -
Journal of Helminthology Oct 2018Dipetalonema gracile is a common parasite in squirrel monkeys (Saimiri sciureus), which can cause malnutrition and progressive wasting of the host, and lead to death in...
Dipetalonema gracile is a common parasite in squirrel monkeys (Saimiri sciureus), which can cause malnutrition and progressive wasting of the host, and lead to death in the case of massive infection. This study aimed to identify a suspected D. gracile worm from a dead squirrel monkey by means of molecular biology, and to amplify its complete mitochondrial genome by polymerase chain reaction (PCR) and sequence analysis. The results identified the worm as D. gracile, and the full length of its complete mitochondrial genome was 13,584 bp, which contained 22 tRNA genes, 12 protein-coding genes, two rRNA genes, one AT-rich region and one small non-coding region. The nucleotide composition included A (16.89%), G (20.19%), T (56.22%) and C (6.70%), among which A + T = 73.11%. The 12 protein-coding genes used TTG and ATT as start codons, and TAG and TAA as stop codons. Among the 22 tRNA genes, only trnS1AGN and trnS2UCN exhibited the TΨC-loop structure, while the other 20 tRNAs showed the TV-loop structure. The rrnL (986 bp) and rrnS (685 bp) genes were single-stranded and conserved in secondary structure. This study has enriched the mitochondrial gene database of Dipetalonema and laid a scientific basis for further study on classification, and genetic and evolutionary relationships of Dipetalonema nematodes.
Topics: Animals; Base Composition; Base Sequence; China; Dipetalonema; Dipetalonema Infections; Genome, Helminth; Genome, Mitochondrial; Monkey Diseases; Phylogeny; Saimiri
PubMed: 30326978
DOI: 10.1017/S0022149X18000871 -
Journal of Helminthology May 2019Dipetalonema caudispina (Molin, 1858) and D. gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae) are two of six known species of filarial nematodes that parasitize...
Dipetalonema caudispina (Molin, 1858) and D. gracile (Rudolphi, 1809) (Filarioidea: Onchocercidae) are two of six known species of filarial nematodes that parasitize Neotropical non-human primates. Adult filariae were collected from the thoracic and abdominal cavities of 38 of 44 specimens of Sapajus macrocephalus (Spix, 1823) and nine of ten specimens of Cebus albifrons (Humboldt, 1812) (Primates: Cebidae), distributed in the Yavarí-Mirín river basin and used locally for human consumption. Co-occurrence of D. caudispina and D. gracile is reported for the first time, with a prevalence of 18.5% (10 of 54 hosts examined). Our finding of D. caudispina and D. gracile in cebids from the Peruvian Amazon constitutes a new geographical record for both filariae, two new host records for D. caudispina, and the first report of D. gracile in S. macrocephalus. In addition, we provide morphometric data for D. caudispina, complementing the original description, as well as scanning electron microscopy details on the structure of the area rugosa and number of caudal papillae in males.
Topics: Abdominal Cavity; Animals; Biometry; Cebinae; Coinfection; Dipetalonema; Dipetalonema Infections; Microscopy, Electron, Scanning; Monkey Diseases; Peru; Prevalence; Thoracic Cavity; Topography, Medical
PubMed: 29606157
DOI: 10.1017/S0022149X18000287 -
International Journal For Parasitology.... Aug 2017Parasite-host relationships are influenced by several factors intrinsic to hosts, such as social standing, group membership, sex, and age. However, in wild populations,...
Parasite-host relationships are influenced by several factors intrinsic to hosts, such as social standing, group membership, sex, and age. However, in wild populations, temporal variation in parasite distributions and concomitant infections can alter these patterns. We used microscropy and molecular methods to screen for naturally occurring haemoparasitic infections in two Neotropical primate host populations, the saddleback () and emperor () tamarin, in the lowland tropical rainforests of southeastern Peru. Repeat sampling was conducted from known individuals over a three-year period to test for parasite-host and parasite-parasite associations. Three parasites were detected in including , , spp., while only hosted the latter two. Temporal variation in prevalence was observed in and spp, confirming the necessity of a multi-year study to evaluate parasite-host relationships in this system. Although callitrichids display a distinct reproductive dominance hierarchy, characterized by single breeding females that typically mate polyandrously and can suppress the reproduction of subdominant females, logistic models did not identify sex or breeding status as determining factors in the presence of these parasites. However, age class had a positive effect on infection with and , and adults demonstrated higher parasite species richness than juveniles or sub-adults across both species. Body weight had a positive effect on the presence of spp. The inclusion of co-infection variables in statistical models of parasite presence/absence data improved model fit for two of three parasites. This study verifies the importance and need for broad spectrum and long-term screening of parasite assemblages of natural host populations.
PubMed: 28393014
DOI: 10.1016/j.ijppaw.2017.03.004 -
Veterinary Clinical Pathology Mar 2017A cat with multiple subcutaneous nodules suggesting a soft tissue sarcoma by physical and computed tomographic examination was diagnosed as being affected by...
A cat with multiple subcutaneous nodules suggesting a soft tissue sarcoma by physical and computed tomographic examination was diagnosed as being affected by subcutaneous filariosis based on cytologic and ultrasonographic assessments. Nodules were surgically removed and extracted nematodes were identified by PCR as Dirofilaria repens. Furthermore, DNA of Dipetalonema dracunculoides (syn. Acantocheilonema dracunculoides) was detected by PCR, with no evidence of circulating microfilariae. To the best of the authors' knowledge, this represents the first report describing adults of D repens in multiple subcutaneous nodules in a cat. Cytopathologic examination allowed characterization of the parasitic nature of the nodules. Veterinary practitioners should be aware of the possible nodular presentation of D repens in cats and should include D repens in the differential diagnosis of subcutaneous neoformations in the cat.
Topics: Animals; Cat Diseases; Cats; Dirofilaria repens; Dirofilariasis; Female; Fibrosarcoma; Microfilariae; Tomography, X-Ray Computed
PubMed: 27935633
DOI: 10.1111/vcp.12433