From the Guidelines
Filariasis should be treated with diethylcarbamazine (DEC) at 6 mg/kg in 3 divided doses for 14 days, plus doxycycline at 200 mg daily for 6 weeks, as this combination has been shown to be effective in managing the disease. The treatment of filariasis is crucial to prevent the progression of the disease to chronic, irreversible lymphatic damage. According to the UK guidelines for the investigation and management of eosinophilia in returning travellers and migrants 1, the prepatent period for Wuchereria bancrofti is 7-8 months, and the incubation period can vary from 4 weeks to 16 months. The disease is transmitted through the bite of mosquitoes, including Aedes spp., Anopheles spp., and Culex.
Clinical Presentation and Investigations
The clinical presentation of filariasis can range from asymptomatic to acute fever and localized skin inflammation, followed by chronic lymphoedema and scrotal oedema/hydrocoele. Investigations for filariasis include serology and nocturnal blood microscopy. It is essential to exclude onchocerciasis and loiasis if the patient has traveled to co-endemic areas.
Treatment and Prevention
The recommended treatment for filariasis is a combination of DEC and doxycycline, as mentioned earlier 1. In cases of onchocerciasis or loiasis co-infection, specialist input is advised. Prevention of filariasis involves protecting against mosquito bites using insect repellents, bed nets, and wearing protective clothing. Mass drug administration programs in endemic areas use annual doses of these medications to reduce transmission.
Key Considerations
- The disease can cause significant morbidity and mortality if left untreated
- Early treatment is crucial to prevent progression to chronic, irreversible lymphatic damage
- Specialist input is advised in cases of co-infection or complex presentations
- Prevention measures should be taken to reduce the risk of transmission in endemic areas 1
From the Research
Treatment Options for Filarisis
- Various treatment options are available for filariasis, including diethylcarbamazine (DEC), ivermectin, and albendazole 2, 3, 4, 5, 6
- Chemotherapy against filarial Wolbachia endosymbionts with doxycycline has shown higher antiparasitic efficacy in onchocerciasis and lymphatic filariasis and also improved disease 2
- A regimen of 6-week/100 mg doxycycline per day sterilized adult female Onchocerca volvulus, and 200 mg doxycycline per day for 4 or 6 weeks revealed 50 and 60% macrofilaricidal effects, respectively 2
Efficacy of Different Treatment Regimens
- Single-dose DEC/Alb dramatically reduces blood microfilaria (MF) counts, but most treated subjects fail to completely clear MF after a single dose 4
- Multi-dose DEC/Alb was significantly more effective than single-dose therapy for reducing and clearing microfilaremia 4
- A single dose of DEC at 6 mg/kg reduced mean mf density by ca. 90% 1 year after treatment, and a single dose of ivermectin at ca. 400 µg/kg was more effective than DEC in reducing mf density during the first year 6
Global Programme to Eliminate Lymphatic Filariasis
- The Global Programme to Eliminate Lymphatic Filariasis (GPELF) started its worldwide activities in 2000, with the target of elimination by 2020 6
- The basic strategy is to conduct annual single-dose mass drug administrations (MDAs) for 4-6 years, using DEC 6 mg/kg plus albendazole 400 mg or ivermectin 200-400 µg/kg plus albendazole 400 mg 6
- The GPELF achieved impressive results in terms of parasitological cure/improvement, clinical benefits, social and economic impacts, and mobilizing hundreds of millions of local people to support MDAs 6