Clinical and laboratory aspects of filariasis

Abstract

Human filarial infections afflict over 150 million persons worldwide and are major causes of morbidity in many developing countries. Onchocerca volvulus infection is a leading preventable cause of blindness, while bancroftian and brugian filariasis may produce lymphatic obstruction of the genitalia and extremities (elephantiasis). Definitive diagnosis of these helminthic infections currently depends on demonstration of microfilariae in host tissues, i.e., the skin in the case of O. volvulus and the bloodstream in the cases of Wuchereria bancrofti and Brugia malayi. Many investigations are now directed at developing specific and sensitive serum antigen assays that will allow diagnosis of active infection (i.e., presence of adult-stage parasites) in the absence of detectable microfilariae. With respect to the immunology of these parasitic infections, efforts are being directed at elucidating the role of T- and B-cell responses in the development of pathologic lesions and resistance to reinfection. These data as well as molecular biologic approaches to identify and study filarial molecules which are immunogenic are discussed. Finally, since treatment of filariases at present depends on antiparasitic drugs, the clinical indications and dosages of diethylcarbamazine and ivermectin are summarized.

Transmission of Tropical and Geographically Restricted Infections during Solid-Organ Transplantation

“…There are eight species of filariae that usually infect humans, and of these, four (Wuchereria bancrofti, Brugia malayi, Onchocerca volvulus, and Loa loa) cause the most severe infections (268).…”

The treatment of chyluria secondary to advanced carcinoma of the prostate

“…Chyluria and other chronic manifestations of filariasis, including lymphoedema and hydrocele, may occur many years after the death of the adult worm. 4,16 Furthermore, reliable detection of microfilariae in a thick blood film Chyluria and advanced carcinoma of the prostate SA Cluskey et al from an infected individual may depend on the time of day that the specimen was obtained. 16 Ultrasound scanning is utilised in some endemic regions to identify adult worms in the lymphatic vessels around the spermatic cord.…”

“…4,16 Furthermore, reliable detection of microfilariae in a thick blood film Chyluria and advanced carcinoma of the prostate SA Cluskey et al from an infected individual may depend on the time of day that the specimen was obtained. 16 Ultrasound scanning is utilised in some endemic regions to identify adult worms in the lymphatic vessels around the spermatic cord. 17 Detection of antibodies against the adult worm is considered to be a reliable test for infection, 18 although this was not available to us.…”

Expression of different filarial parasite adult stage antigens during course of DEC treatment in mouse model of Brugian filariasis

“…44-14 kDa of B. malayi (Cheirmaraj and Harinath, 1991), 25 kDa (Kazura et al, 1986), 92-25 kDa (Parab et al, 1990) of Mf were earlier found to be immunoreactive using human bancroftian sera. Molecular weight < 200,[40][41][42][43][44][30][31][32][33][34][35][36][23][24][25][26][27][28][20][21][22] kDa of B. malayi adult induced protection against L 3 in Balb/c mice Hayashi et al, 1989), 97 kDa of B. malayi Mf and adults induced partial stage specific protection against B. malayi Mf in mice (Nanduri and Kazura, 1989).…”