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Preventing Two Diseases with One Net

Insecticide-Treated Bed Nets

A Nigerian woman and her baby show their insecticide-treated bed net. (Courtesy The Carter Center/E. Staub)

Insecticide-treated bednets (ITNs) decrease death and disease due to malaria, and their mass distribution to children under five and to pregnant women is now a major intervention against malaria in Africa. However, the distribution of ITNs can be costly and difficult to organize, and these issues can prevent them from getting to the remote populations who need them most. Public health workers have improved coverage of ITNs by linking their distribution with campaigns against other health problems such as measles, polio, and intestinal worms. Recent experience in Nigeria shows successful linkage with yet another disease, lymphatic filariasis.

Lymphatic Filariasis

Wuchereria bancrofti is the main agent of lymphatic filariasis in Nigeria. Adult worms (shown here) clog and destroy the lymphatic drainage system, leading to elephantiasis. Female worms (right) measure up to 4 inches, while males (left) are smaller. (CDC photo)

Lymphatic filariasis (LF), a parasitic infection transmitted by mosquitoes, affects over 120 million people in more than 80 countries. The adult female worms generate young worms (microfilariae), which circulate in the blood and which, when picked up by a mosquito, can result in the infection of another person. LF is a leading cause of disability worldwide. The adult worms live for years in the infected person’s lymphatic system, which they clog and damage. This process can result in lymphedema and elephantiasis, an incapacitating swelling in the legs, genital organs, or arms. The affected parts are often secondarily infected by bacteria, and the disease may persist a lifetime.

Global Campaign to Eliminate Lymphatic Filariasis

Following a 1993 report by the Carter Center's International Task Force for Disease Eradication, the World Health Organization in 1997 called for the elimination of LF. This task is currently

A woman in Nigeria washes her left leg and foot, swollen by lymphatic filariasis; more advanced cases can be very crippling; frequent washing with soap and water helps prevent bacterial superinfection. (Courtesy The Carter Center/F. Richards)

Joining Efforts in Nigeria

In Africa, LF and malaria often occur in the same locales and are transmitted by the same mosquitoes. Combining the health interventions directed against these two diseases into a single bundle may prove beneficial. Sharing the resources may reduce costs, and protection from the mosquito vectors may reduce transmission of both diseases.

This is particularly true when considering that children under five and pregnant women do not receive the drugs during MDA campaigns but are the target groups for receiving ITNs. Since 2000, the ministries of health of two states in central Nigeria (Plateau and Nasarawa states), assisted by the Nigerian Federal ministry of health, the Carter Center’s Lymphatic Filariasis Program, and CDC, have organized yearly MDAs to eliminate LF. These have evolved into well-established systems for drug distribution, with more than 3.2 million persons treated in 2004.

Going one step further, the states’ LF and malaria programs developed a collaboration to fight both diseases simultaneously, by piggybacking to the MDA campaign the distribution of ITNs donated by the Roll Back Malaria Partnership. In two demonstration districts, Kanke and Akwanga (combined population approximately 218,000), the two programs developed logistical systems, trained distributors, and educated local communities in how to use ITNs.

Results

During a three-month period (July-September 2004), 38,600 ITNs were distributed in 159 villages, free of charge to children under five and pregnant women, during the MDA process. About 148,000 persons were treated with medicines for LF at the same time.

Children under five and pregnant women do not receive drugs against lymphatic filariasis, but insecticide-treated bed nets can protect them against both filariasis and malaria. (Courtesy The Carter Center/A. Eigege)

This article contributed by the The Carter Center.

* Drug brand names and manufacturers are mentioned for informational purposes only and do not imply endorsement by CDC, the U.S. Public Health Service, or the U.S. Department of Health and Human Services.