Skip to main content Accessibility help

Repeated infection of cats with Brugia pahangi: parasitological observations

  • D. A. Denham (a1), F. Medeiros (a1), C. Baldwin (a1), H. Kumar (a1), I. C. T. Midwinter (a1), D. W. Birch (a1) and A. Smail (a1)...


Cats were repeatedly inoculated with infective larvae of Brugia pahangi. On parasitological grounds they could be divided into 5 groups. Group I – most cats (some 70%) became microfilaraemic (mf+) and retained high levels of microfilariae (mf) in their blood for over 2 years. In some Group I cats mf counts stabilized at high levels whilst in others mf counts continued to increase. Large numbers of fecund adult worms were recovered from their lymphatics. Adult counts were not made on the cats in the current experiments but over 100 adults have been recovered from ‘super-susceptible’ cats. Large amounts of B. pahangi adult antigen were consistently present in the serum of all Group I cats. About 30% of cats became amicrofilaraemic (mf–). In these cats the peak mf levels were seldom above 10000 mf/ml. Group II – these cats had less than 10 000 mf/ml and low antigen levels. After more than 1 year of being repeatedly infected B. pahangi adult antigen slowly declined and eventually could no longer be detected in their serum and the number of mf declined very slowly after the fall in antigen levels. This shows that in Group II cats the adult worms die and as the cats are resistant to the development of the continuing weekly inoculation of L3 no new adults can develop. Group III – these cats became mf – during the first year of infection but remained B. pahangi antigen-positive for many weeks after this and, at autopsy, had living adults in their lymphatics. Group IV – in these cats there was a sudden decline in the number of mf, usually in the first year and after they have received a relatively small number of re-infections. Circulating adult B. pahangi antigen disappeared from the serum within a short time of the loss of mf and at autopsy no adult female worms were found. Group V – these cats do not become mf+ when infected. These groups are compared to the parasitological groups seen in areas endemic for infection with Wuchereria bancrofti.



Hide All
Denham, D. A. (1982). The methodology of screening for filarial activity using Brugia pahangi. In Animal Models in Parasitology (ed. Owen, D.), pp. 93104. London: Macmillan.
Denham, D. A., Dennis, D. T., Ponnudurai, T., Nelson, G. S. & Guy, F. (1971). Comparison of a counting chamber and thick smear methods of counting microfilariae. Transactions of the Royal Society of Tropical Medicine and Hygiene 65, 521–6.
Denham, D. A., Ponnudurai, T., Nelson, G. S., Rogers, R. & Guy, F. (1972). Studies with Brugia pahangi. 2. The effect of repeated infection on parasite levels in cats. International Journal for Parasitology 2, 401–7.
Denham, D. A., Mcgreevy, P. B., Suswillo, R. R. & Rogers, R. (1983). The resistance to re-infection of cats repeatedly inoculated with infective larvae of Brugia pahangi. Parasitology 86, 1118.
Dennis, D. T. & Kean, B. H. (1971). Isolation of microfilariae: report of a new method. Journal of Parasitology 57, 1146–7.
Forsyth, K. P., Spark, R., Kazura, J. W., Broen, G. V., Peters, P., Heywood, P., Dissanayake, S. & Mitchell, G. F. (1985). A monoclonal antibody-based immunoradiometric assay for detection of circulating antigen in Bancroftian filariasis. Journal of Immunology 134, 1172–7.
Hussain, R., Grogl, M. & Ottesen, E. A. (1987). IgG antibody subclasses in human filariasis. Differential subclass recognition of parasite antigens correlates with different clinical manifestations of infection. Journal of Immunology 139, 2794–8.
Kumar, H., Baldwin, C., Birch, D. W., Denham, D. A., De Medeiros, F. & Smail, A. (1991). Circulating filarial antigen in cats infected with Brugia pahangi is indicative of the presence of adult worms. Parasite Immunology 13, 405–12.
Ottesen, E. A. (1984). Immunological aspects of lymphatic filariasis and onchocerciasis in man. Transactions of the Royal Society of Tropical Medicine and Hygiene 78, Suppl. 918.
Suswillo, R. R., Denham, D. A. & Mcgreevy, P. B. (1982). The number and distribution of Brugia pahangi in cats at different times after a primary infection. Acta Tropica 39, 151–6.
Weil, G. J., Jain, D. C., Santhanam, S., Malhotra, A., Kumar, H., Sethumadhavan, K. V. P., Liftis, F. & Ghosh, T. K. (1987). A monoclonal antibody-based enzyme immunoassay for detecting parasite antigenemia in bancroftian filariasis. Journal of Infectious Diseases 156, 350–5.



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed