Abstract

Brugia timori is a human filarial parasitic nematode (roundworm) which causes the disease "Timor filariasis." While this disease was first described in 1965, the identity of "Brugia timori" as the causative agent was not known until 1977. In that same year, "Anopheles barbirostris" was shown to be its primary vector. There is no known animal reservoir host.

Characteristics of "Brugia timori"

The microfilariae of "Brugia timori" are longer and morphologically distinct from those of "Brugia malayi" and "Wuchereria bancrofti", with a cephalic space length-to-width ratio of about 3:1. "B. timori" more closely resembles the symptoms caused by "B. malayi" and morphologically resembles "B. malayi". Also, the sheath of "B. timori" does not stain pink with Giemsa stain as is observed with "B. malayi" and "W. bancrofti".

"Brugia timori" filariasis

Like other human filariasis infections, "Brugia timori" filariasis causes acute fever and chronic lymphedema. The life cycle of "Brugia timori" is very similar to that of "Wuchereria bancrofti" and "Brugia malayi", leading to nocturnal periodicity of the disease symptoms. Eosinophilia is common during acute stages of infection.

So far "Brugia timori" has only been found in the Lesser Sunda Islands of Indonesia. It is locally confined to areas inhabited by its mosquito vector, which breeds in rice fields. One study of the prevalence of infection in Mainang village, Alor Island, found microfilariae in the blood of 157 of 586 individuals (27%), with 77 of them (13%) exhibiting lymphedema of the leg.

Morphology

"B. timori" microfilariae have nuclei that extend to the tip of the tail, which is also characteristic of "B. malayi" but not "W. bancrofti". "B. timori" microfilariae are slightly larger than "B. malayi" microfilariae.

Endosymbiont

Aside from vectoring "Brugia" species, mosquitoes also maintain "Wolbachia" spp. which has been found to be an obligate intracellular bacterial endosymbiont of "Brugia" spp. "Wolbachia" supports essential biochemical pathways necessary for the survival of "Brugia", especially processes such as embryogenesis and molting.

Treatment

Anthelmintics such as diethylcarbamazine and albendazole have shown promise in the treatment of "Brugia timori" filariasis. Some researchers are confident that "Brugia timori" filariasis may be an eradicable disease. Related filarial nematodes have been found highly sensitive to elimination of their endosymbiotic Wolbachia bacteria, and this may be a powerful attack route against "Brugia timori" as well.