This paper reports the experimental transmission of a bird parasite into jirds. Infective larvae of Cardiofilaria nilesi obtained from laboratory colonized Coquillettidia crassipes mosquitoes which had fed on an infected chicken were inoculated subcutaneously into jirds. The number of larvae per jird varied from 10 to 228. Microfilaraemia appeared 22 to 89 days after inoculation of the infective larvae. Experiments were carried out with 24 jirds through six generations extending over a period of 22 months and 17 produced patent infections. At present 8 infected jirds are being maintained in the laboratory; their patent periods ranging from 6 to 13 months. However, the longest patent period observed was about thirteen months. The percentage of adults recovered in autopsied jirds ranged from 0 to 40 with an average of 16. The chicken showed a microfilarial periodicity with the peak microfilarial density around 2200 hours. However, in jirds there was a change in sub-periodicity. This model in the jird may be very useful for the screening of filaricides and in immunological work.
Breinlia booliati Singh & Ho, 1973 first described from Peninsular Malaysia has been shown to infect a large range of murids ranging in distribution from southern Thailand, Peninsular Malaysia, Sarawak to Ciloto, Indonesia. Probably further work will reveal a greater host range as well as its geographical distribution. The vectors involved in its transmission need to be elucidated.
Background: Dirofilaria ursi is a filarial nematode that parasitizes the subcutaneous tissues of the American black bear (Ursus americanus) and Japanese black bear (Ursus thiabetanus japonicus). D. ursi that has parasitized black bears has the potential to subsequently infect humans. In addition, extra-gastrointestinal anisakiasis is less common in Japan.
Case presentation: We report a case of ventral subcutaneous anisakiasis and dorsal subcutaneous dirofilariasis that was acquired in Fukushima, in the northern part of Japan. The patient was an 83-year-old Japanese female, and subcutaneous parasitic granulomas were present on her left abdomen (near the navel) and left scapula. A pathological examination of the surgically dissected tissue sections from each region demonstrated eosinophilic granulomas containing different species of parasites. To enable the morphological and molecular identification of these parasites, DNA was extracted from paraffin-embedded sections using DEXPAT reagent, and the cytochrome oxidase 2 (COX2), internal transcribed spacer 1 (ITS1), 5.8S and ITS2 regions of the Anisakis larvae, and the 5S rRNA region of the male Dirofilaria were sequenced. The PCR products were examined and compared with DNA databases. Molecular analysis of the COX2 and 5S rRNA sequences of each worm revealed that the nematode found in the ventral region belonged to Anisakis simplex sensu stricto (s.s.) and the male Dirofilaria found in the dorsal region was classified as D. ursi.
Conclusion: The present case showed a combined human case of D. ursi and A. simplex s.s. infections in subcutaneous tissues. The results of this study will contribute to the identification of unknown parasites in histological sections.
Glucose phosphate isomerase of subperiodic Brugia malayi was studied by horizontal starch-gel electrophoresis. Two heterophenotypes, each represented by 3 bands of enzyme activity, were found among 38 parasites studied. This finding is attributed to the occurrence of 2 Gpi gene loci.
Histochemical demonstration of acid phosphatase activity in microfilariae gives sufficiently characteristic and consistent results for the differentiation of even closely related species. No difference could be detected among nocturnally periodic, nocturnally subperiodic and diurnally subperiodic Brugia malayi, but they could readily be distinguished from B. pahangi. Similarly, Dirofilaria repens could be readily distinguished from D. immitis and B. booliati from B. sergenti. The enzyme distribution pattern of a Malaysian rural strain of Wuchereria bancrofti was different from those of other regions.
Infective larvae of Wuchereria, Brugia, Breinlia, Dirofilaria and Setaria species from an experimental vector, Aedes togoi, are compared. The distinctive bubble-like caudal papillae of Wuchereria bancrofti are readily distinguishable from the protuberant ones of Brugia spp; the 'ear-like' papillae of Breinlia are distinct from the 'knob-like' ones of Dirofilaria or the 'thorn-like' terminal papilla of Setaria.
Accurate diagnosis of human filarial infections still remains a problem for clinicians and co-ordinators of filariasis control programs. Diagnosis of filariasis is based on parasitological, histopathological, clinical and immunological approaches. No significant advances have been made for the first three approaches although some refinements in their use and interpretation of results have occurred. For the immunological approach, intradermal tests and antibody detection assays using crude parasite extracts generally lack specificity and/or sensitivity to discriminate between past and present filarial infections in humans. Antigen detection assays would therefore provide a more accurate indication of active filarial infections. Several monoclonal antibodies to various stages of lymphatic filarial parasites have been developed and appear potentially useful for filarial antigen detection.
The development of Breinlia booliati is described in its natural host, Rattus sabanus and in an inbred strain of laboratory albino rat. The growth of the parasite is similar in both the rat hosts. The third moult occurs between six-eight days and the final moult between 24-28 days. Larvae were recovered initially from the skin and carcass. After five weeks, developing stages were seen only in the thoracic and abdominal cavities, the site of development of the adult worms. Worms became sexually mature by 11-12 weeks and there was considerable growth in length of the female worms after this stage.