The domestic cat as a host for Brugian filariasis in South Kalimantan (Borneo), Indonesia.

Three hundred and twenty-five domestic cats (Felis catus) from six villages of the Hulu Sungai Tengah and Banjar Regency of South Kalimantan (Borneo), Indonesia, were examined for filarial nematodes. Parasites were found in 66 cats, of which 61 (92.4%) had Brugia pahangi, four (6.1%) has B. malayi and one (1.5%) had Dirofilaria repens. Infection rates ranged from 11% to 22% in cats from secondary forest/rice-field habitats, from 15% to 30% in open village/rice-field habitats, to 50% in an open coastal village. In all cases the infection rate of B. malayi in man was greater than in cats from the same collecting area. The number of B. pahangi microfilariae per 20 microliter cat blood ranged from 34 at 1000 hours to 571 at 2200 hours. The results of this study suggest that in this region of Indonesia the domestic cat is not an important host for maintaining B. malayi.

Effect of treatment with diethylcarbamazine on immune responses to filarial antigens in patients infected with Brugia malayi.

We studied the effect of treatment with diethylcarbamazine (DEC) on immune responses to parasite antigens in humans infected with Brugia malayi. In vitro lymphocyte proliferative responses to microfilarial antigens increased in patients who became amicrofilaremic after treatment with DEC. No changes in reactivity were observed in amicrofilaremic individuals who were given DEC or in a small number of patients who remained microfilaremic after treatment. Reactions to other antigens (PPD and SKSD) were not affected by drug treatment. Serum titers of antibodies to the sheath of B. malayi microfilariae did not significantly change during the period of observation. These findings indicate that DEC partially reverses the state of cellular unresponsiveness to parasite antigens associated with patient filarial infections.

Blood parasites of wild and domestic animals from South Kalimantan (Borneo), Indonesia.

Wild and domestic animals trapped from forests, villages, and rice fields in South Kalimantan (3 degrees 20' S, 115 degrees 02' E, 25 m) were examined for blood parasites using Giemsa stained thick and thin blood films and Nuclepore filter preparations of peripheral vein and heart puncture blood. Presbytis cristatus (silvered leaf monkey) (25%) and Felis catus (domestic cat) (7%) were infected with Brugia malayi and B. pahangi. In addition, P. cristatus was infected with Wuchereria kalimantani (35%); Cardiofilaria sp. (1%) and Dirofilaria sp. (1%). Microfilariae of Cardiofilaria were also recovered from Callosciurus notatus (squirrel), Pitta sordida (bird), Pycnonotus goiavier (bird) and Gallus gallus (bird). Paradoxurus hermaphroditus (civet) and Muntiacus muncak (barking deer), were positive for Dirofilaria sp. Bos indicus (cow) for Onchocerca sp. and Nectarinia jugularis (bird) for Splendidofilaria sp. Plasmodium coatneyi was found in 22% of the P. cristatus examined. Plasmodium sp. was also recovered from Zaocys fuscus and Ahaetulla prasina (reptile); Muscicapa sp. Lonchura malacca, Orthotomus sericeus, Rhipidura javanica, Treron vernans, Pycnonotus melanoleucus and G. gallus (bird). In addition 39% of the Cynopterus brachyotis and 29% of C. horsfieldi (fruit bats) were infected with Hepatocystis pteropi. A single G. gallus was infected with Leucocytozoon sabrazesi and another with Trypanosoma sp.

Studies on filariasis in the Pacific. 5. Brugia malayi filariasis in treated and untreated populations of South Borneo.

A blood survey employing membrane filter concentration (MFC) and examination of stained 20 c.mm thick blood films as diagnostic methods was carried out in Banjar Regency of South Borneo, an area of endemic B. malayi filariasis. In untreated populations the mf rate, as revealed by MFC, ranged from 23.2% for the 5-9 year old group to 43.7% for the greater than 50 year old group. For all age groups approximately one half of the microfilaraemias were of a low grade nature, diagnosed by MFC only. In a population that had been subjected to mass DEC administration 1 1/2 years prior to this survey, the MFC-diagnosed rate was 15%. Approximately two thirds of these infections were of very low density, the average density being 2.2 mf/ml.