Lesions of the Lymphatic System in Early Filariasis

Abstract

Summary 1. This is a report on the early lesions of acute filarial lymphadenitis and lymphangitis, due presumably to Wuchereria bancrofti. 2. Material was obtained by diagnostic biopsy on 17 otherwise healthy young white men who had resided in the islands for 4 months and were exposed to the bites of mosquitoes harboring the non-periodic form of Wuchereria bancrofti. 3. The clinical manifestations included acute epididymitis, acute transient retrograde lymphangitis and lymphadenopathy especially of the upper extremities. Intradermal tests were positive in all but one case. Microfilariae were not demonstrated in the peripheral blood during their stay in the hospital and elephantiasis did not occur. 4. Adult male and female filarial worms were found in five of the specimens. Both living and dead worms were present and the females contained in their uteri large numbers of eggs and microfilariae which appeared morphologically mature. No free microfilariae were found in the tissues. 5. Cultures of the biopsies, as well as tissue sections specially stained for bacteria, were negative, indicating that the lesions were due to the worms and not to bacteria. 6. The tissue reactions in the nodes consisted of graulomatous inflammation with marked hyperplasia of the macrophage (reticulo-endothelial) system and tissue eosinophilia. The lymphatic vessels showed reticulo-endothelial hyperplasia, lymph thrombi, and varying degrees of inflammation with or without thrombosis. 7. It is suggested that the absence of microfilariae from the blood may be due to the avascular nature of the granulomas, the hyperplasia of macrophages, and the small numbers of worms found in the specimens. 8. The history of these patients proves that white persons can be infected during short visits to endemic areas, and that signs and symptoms of filariasis may develop as early as 3 months after the first exposure to infected mosquitoes.