Lymphatic filariasis

Treatment and prevention

Treatment

Endemic communities

The primary goal of treating affected communities is to eliminate microfilariae from the blood of infected individuals in order to interrupt transmission of infection by mosquitoes. Studies have shown that > 5 years of MDA with preventive chemotherapy reduces microfilariae from the bloodstream and prevents the spread of microfilariae to mosquitoes. Preventive chemotherapy involves a combined dose of two medicines given annually to an entire at-risk population as follows: albendazole (400 mg) plus ivermectin (150–200 μg/kg) or diethylcarbamazine citrate (DEC) (6 mg/kg). MDA with albendazole (400 mg) alone should be given preferably twice per year to stop the spread of lymphatic filariasis in areas where Loa loa is present.

Individuals

All people with filariasis who have microfilaraemia or a positive antigen test should receive antifilarial drug treatment to eliminate microfilariae. Unfortunately, the medicines available have limited effect on adult worms. Infected patients can be treated with one of the following regimens:

  • a single dose of a combination of albendazole (400 mg) with ivermectin (150–200 μg/kg) in areas where onchocerciasis is co-endemic; in areas where onchocerciasis is non co-endemic, either
  • a single dose of a combination albendazole (400 mg) plus diethylcarbamazine (6 mg/kg) or
  • DEC (6 mg/kg) alone for 12 days.
© WHO/J. King

Managing morbidity and preventing disability

Management of morbidity and disability prevention (MMDP) in lymphatic filariasis require a broad strategy involving both secondary and tertiary prevention. Secondary prevention includes simple hygiene measures, such as basic skin care and exercise, to prevent ADL and progression of lymphoedema to elephantiasis. For management of hydrocoele, surgery may be appropriate. Tertiary prevention includes psychological and socioeconomic support for people with disabling conditions to ensure that they have equal access to rehabilitation services and opportunities for health, education and income. Activities beyond medical care and rehabilitation include promoting positive attitudes towards people with disabilities, preventing the causes of disabilities, providing education and training, supporting local initiatives, and supporting micro- and macro-income-generating schemes. The activities can also include education of families and communities to help patients with lymphatic filariasis to fulfil their roles in society. Thus, vocational training and appropriate psychological support may be necessary to overcome the depression and economic loss associated with the disease. MMDP must be continued in endemic communities after MDA has stopped and after validation, as chronically affected patients are likely to remain in these communities.

Prevention

Avoidance of mosquito bites through personal protection measures or community-level vector control and participation in MDA is the best option to prevent lymphatic filariasis.

Other diseases related to lymphatic filariasis

Scabies

One of the commonest dermatological conditions, scabies accounts for a substantial proportion of skin disease in developing countries. Human scabies is a parasitic infestation caused by Sarcoptes scabiei var hominis.

Podoconiosis

A type of tropical lymphoedema, podoconiosis results from a genetically determined abnormal inflammatory reaction to mineral particles in irritant red clay soils derived from volcanic deposits. It is mostly found in highland areas of tropical Africa, Central America and north-west India. It is a non-parasitic disease and, like lymphatic filariasis, results in impairments due to lymphoedema. As is the case for lymphatic filariasis, a basic package of care can alleviate suffering and prevent further progression of disease and disability.

Tungiasis

A neglected cutaneous parasitic skin disease that affects humans and animals alike. It thrives where living conditions are precarious, such as villages located in remote beaches, communities in the rural hinterland and shanty towns of big cities. In these settings the poorest of the poor carry the highest burden of disease. It has been noted that people affected by tungiasis and who are exposed to ivermectin have benefited from treatment.