nan Purnomo

Secreted and surface antigens from larval stages of Wuchereria bancrofti, the major human lymphatic filarial parasite

Antigenic proteins of microfilariae and infective larvae of Wuchereria bancrofti have been identified by intrinsic and extrinsic radiolabelling, and specific immunoprecipitation with sera from filarial patients. From 125I surface-labelling experiments, the most prominent antigen on both stages is of relative molecular mass (Mr) 17 000, while a molecule of similar size is both synthesized and released in vitro following labelling with [35S]methionine. A second similarity between the two stages is the production and secretion of a Mr 21 000 component, which is, however, not detected on the worm surfaces. A series of additional proteins from larval W. bancrofti are described from each parasite compartment (secreted, surface and somatic) and the antigenicity and specificity of these components explored with serum from patients with filariasis due to W. bancrofti or Brugia species, and with onchocerciasis. Among additional molecules released in vitro we have found a Mr 51 000 antigen from both stages, and also several proteins which are not recognised by antibody from human filarial patients.

Absence of malaria mortality in villagers with chloroquine-resistant Plasmodium falciparum treated with chloroquine

We carried out a series of malaria studies in Robek , Flores, Indonesia, a coastal village of 900 farmers and fishermen where malaria is hyperendemic by parasite rate and holoendemic by spleen rate. The studies showed that: (i) 28 of 31 isolates (90%) of Plasmodium falciparum were resistant to chloroquine in vitro, (ii) 3 of 12 isolates (25%) were resistant at the R-11 level in vivo, (iii) 376 P. falciparum infections occurred in 301 individuals during one year, (iv) no villagers who were treated with chloroquine for P. falciparum infections during the year died, and (v) increasing the dosage of chloroquine base from 15 to 25 to 37.5 mg/kg led to improved clearing of parasitaemia. We conclude that chloroquine can still be used as the primary antimalarial in Robek , but the dosage may have to be increased to clear parasitaemia.

Rare quadruple malaria infection in Irian Jaya Indonesia.

We report an exceptional finding from a blood slide collected in a remote area in the western half of New Guinea Island (Irian Jaya Province, Indonesia). One adolescent patient was found patently coinfected with all 4 known human malaria species, Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, and Plasmodium ovale. Diagnostic erythrocytic stages of all 4 species were clearly seen in the peripheral blood. A nested polymerase chain reaction, using species-specific primer pairs to detect DNA, helped substantiate this finding. Previous reports from Africa, Thailand, and New Guinea have detected all 4 species in a population but not simultaneously in an individual with a patent, microscopically detectable infection. We believe this quadruple infection represents the first reported natural case of all 4 human malaria parasites observed concurrently in the peripheral blood from a single Giemsa-stained slide.

Towards a filariasis-free community: evaluation of filariasis control over an eleven year period in Flores, Indonesia.

A population of 202 residents in an area endemic for Brugia timori lymphatic filariasis was treated in a diethylcarbamazine control programme commencing in 1977. All individuals were treated twice with diethylcarbamazine on a mass basis with additional selected treatment for cases with manifestations of infection. Clinical features of lymphatic filariasis were recorded annually until 1982, and the population re-assessed in 1988, six years after the completion of chemotherapy. Microfilarial counts were made on each occasion, and circulating filarial antigen levels measured for 1982 and 1988. The results showed a dramatic and sustained reduction in the rate of elephantiasis and adenolymphangitic disease, and of circulating antigenaemia, and the prevalence of microfilaraemia was reduced to zero by the end of the study.

Antigenic characterization of adult Wuchereria bancrofti filarial nematodes.

Adult Wuchereria bancrofti were recovered from infected Presbytis cristatus monkeys and radio-isotope labelled extrinsically with 125I and in vitro with [35S]methionine. 125I labelling of the surface of adult W. bancrofti permitted a comparison between the major surface antigens of this species and those from the related lymphatic filariae, Brugia malayi and B. pahangi. All species bear a prominent Mr 29,000 surface antigen but among the differences observed were the strongly labelled molecules with Mr 58,000 and 67,000 in W. bancrofti which are extremely faint in the Brugia species. The [35S]methionine label was effectively incorporated into somatic parasite proteins in vitro although it was not possible to identify any secreted proteins in this way. The antigenicity of these products was investigated using a variety of sera from homologous and heterologous infections and the immunoprecipitation patterns highlighted particular differences between somatic proteins of male and female worms. One secreted antigen was detected, however, by virtue of its phosphorylcholine epitopes, in the culture medium of mixed adult worms; medium from male W. bancrofti adults was negative although homogenates of either sex of adult W. bancrofti were strongly positive in the same system.

A simple method to control Brugia timori by diethylcarbamazine administration

The results of mass treatment using 50 mg diethylcarbamazine per kg body-weight followed one year later by short term selective re-treatment in a highly endemic area of Brugia timori are described. The criteria for selection of re-treatment are simple and practical for use in rural areas. The microfilaria rate by finger prick decreased from 24% to 0 and by Nuclepore filtration from 30% to 2.5%. The disease rates were also affected favourably. 88% of persons receiving the drug reacted to treatment, this percentage slightly exceeding the total filarial infection rate (71%). The prevalence, onset, duration and nature of side reactions are briefly discussed and related to the presence of microfilaraemia and disease manifestations among the study population.

Periodicity studies of Brugia malayi in Indonesia: Recent findings and a modified classification of the parasite

We have recently reinvestigated the position of Brugia malayi in Indonesia. Periodicity patterns of microfilariae from several endemic areas were mathematically determined. We have also designed a simple method to quantify microfilaria periodicities in these studies. To determine whether periodicity patterns of microfilariae were stable, repeated studies were performed in the same individual or community. Other biological features of the parasite were also investigated. The parasite from each isolate was taxonomically identified as B. malayi. It could be classified into two distinct biological types, one nocturnally periodic and the other aperiodic, nocturnally subperiodic, or nocturnally periodic. We therefore propose to modify Wilsons classification, using the biological behaviour of the parasite in animals as the discriminating feature, and classify the two types as zoophilic and anthropophilic B. malayi.

Filarid parasites of South Kalimantan (Borneo) Indonesia. Wuchereria kalimantani sp. n. (Nematoda: Filarioidea) from the silvered leaf monkey, Presbytis cristatus Eschscholtz 1921.

On the basis of morphological characteristics of adult and microfilarial stages, Wuchereria kalimantani sp. n. (Nematoda: Filarioidea) is described. The parasites were recovered from the inguinal lymph nodes and testes of silvered leaf monkeys (Presbytis cristatus) from a rubber estate, Banjar Regency, South Kalimantan (Borneo), Indonesia. Adult males are characterized by having more than 24 caudal papillae, a left spicule with a simple lamina, four pairs of sessile caudal papillae, a blunt tail, a mean overall length of 41 mm, and sheathed microfilariae with a nude tail tip; accordingly, the parasite is placed in the genus Wuchereria. This is the second species of Wuchereria described on the basis of both adult and embryonic forms, and is the first such species that has been found to infect primates naturally.

Brugia timori sp. n. (nematoda: filarioidea) from Flores Island, Indonesia.

Brugia timori sp. n. from experimentally-infected Mongolian jirds (Meriones unguiculatus) is described. The adult male differs from other Brugia species, except Brugia malayi, in having a spicular ratio of 3 : 1; it differs from B. malayi in having greater numbers of subventral adanal papillae (up to 5 on each side) that are loosely spaced and irregularly positioned about the cloaca, a greater diameter of the capitulum of the left spicule, greater lengths of the proximal- and midsections of the left spicule, and a greater length of the proximal section of the right spicule. The adult female has an ovejector of greater length and width than that of B. malayi. Microfilariae in the blood of persons from whom the parasite lines of this study originated were typical of the Timor type, having a greater total body length than other Brugia spp., a length to width cephalic space ratio of about 3 : 1, and a sheath which did not stain when processed in the usual manner with Giemsa.

Development of the Timor filaría in Aedes togoi: preliminary observations.

Developmental stages of the Timor filaria recovered from experimentally infected Aedes togoi mosquitoes are described. Mosquitoes were dissected and examined for larvae beginning 1 1/2 days and continuing daily for 9 days after they had fed on a carrier on the island of Flores, Indonesia. Timor microfilariae develop rapidly to third-stage larvae within the thoracic muscles of A. togoi: the first molt occurs at 3 1/2 days, the second molt as early as 5 1/2 days, and infective forms are found at 6 1/2 to 7 1/2 days postfeeding. These larvae were compared with similar stages of subperiodic Brugia malayi recovered from A. togoi fed on an infected jird (Meriones unguiculatus) and the features distinguishing larvae of the Timor filaria from those of B. malayi are restricted to the tails of the first-stage forms. The terminal and subterminal nuclei of the Timor larva are generally smaller than those of B. malayi, and there is little if any bulge of the cuticle around them. A constriction of the tail between these nuclei is subtle or absent. The findings of this study support the view that the Timor filaria is a member of the Brugia complex.