No evidence of Wolbachia endosymbiosis with Loa loa and Mansonella perstans.

Endosymbiotic Wolbachia bacteria from different filarial species, including major pathogens of humans such as Wuchereria bancrofti, Brugia malayi and Onchocerca volvulus, seem to play an important role in the development, viability and fertility of these worms. Wolbachia trigger inflammatory host responses as well as adverse reactions against standard treatment regimens and are therefore under investigation as novel treatment targets. We investigated whether Wolbachia are also endosymbiotic in Loa loa and Mansonella perstans. In both male and female adult L. loa, we found no evidence of bacteria by light or transmission electron microscopy. Furthermore, Wolbachia-specific PCR was negative in both L. loa and M. perstans microfilariae. The absence of Wolbachia in both filarial species therefore discourages the use of antibiotics as an adjunct or alternative approach to current treatment concepts for both loiasis and mansonelliasis perstans.

[Surgical worm extraction in loa loa ophthalmia]. / Chirurgische Wurmentfernung bei Loa-Loa-Ophthalmie.

BACKGROUND: Loa Loa is a chronic parasitemic disease which is endemic in the tropical rain forests of Western Africa. Vector of this disease is a mangrove fly with the name Chrysops. Besides the eye worm and skin affections a systemic infection with microfilariae is common. PATIENT: A West African tourist from Bangibe showed up at the university eye clinic. His complaints were a red eye and a mobile subconjunctival tumor (Fig. 1) that showed vermiform movements. The worm was transparent and 4-5 cm in length. After topical anaesthesia and the attempt to paralyze the worm (1) with Pilocarpine 2% it vanished. Two days later the patient showed up in the morning for the planned blood test. No worm was visible at that time but at noontime the blood test was carried out and at that time the worm was visible in the nasal conjunctiva. This time the worm was removed without delay under topical anaesthesia. The worm was fixed with a forceps through the conjunctiva which was opened for 0.5 cm. The worm was grasped with a second forceps and drawn out under massive vermiform movement. Systemic therapy was recommended with Hetrazan (Diethylcarbamazine) using Corticosteroides and Antihistamine to minimize allergic side effects by the therapy due to the systemic microfilariae blood load. Eosinophilia was 8%. CONCLUSIONS: A subconjuctival Loa Loa worm can be removed under topical anaesthesia by fixing it with a forceps through the conjunctiva and opening it and grasping the worm with a second forceps. According to our experience the paralyzation with Pilocarpine cannot be realized. Careful systemic therapy avoiding reported allergic side effects with Hetrazan which is not available in Germany is necessary.