JRS Biodiversity Foundation

Noguchi Memorial Institute for Medical Research

Organization: Noguchi Memorial Institute for Medical Research - NMIMR

Project Location: Ghana

Web Address: www.noguchimedres.org

Title of Grant: "Species diversity in lymphatic filariasis vectors and the potential for targeted vector control in maintaining biodiversity"

Grant Amount: $199,974 over 2 years

Principal Investigator: Daniel Boakye

Organization Background:

The Noguchi Memorial Institute for Medical Research is a semi-autonomous Institute of the University of Ghana established in 1979; and a constituent member of the College of Health Sciences, University of Ghana. The Institute was built and donated to the people of Ghana by the Japanese Government. The Noguchi Memorial Institute for Medical Research is a semi-autonomous Institute of the University of Ghana established in 1979; and a constituent member of the College of Health Sciences, University of Ghana. The Institute was built and donated to the people of Ghana by the Japanese Government.

Grant Description:

This 2 year grant will directly impact how Lymphatic filariasis (LF), a parasitic disease caused by a microscopic thread-like worm (Wuchereria bancrofti), is eliminated in Ghana.

The Problem:

LF affects over 120 million people worldwide. The disease spreads from person to person by mosquito bites. When an infected mosquito bites a person, it may inject the infective larval stage of the worm, into the blood. The worm larvae grow into an adults which mate and produce other larvae, called microfilariae. The microfilariae spread throughout the bloodstream and can be picked up by a blood seeking female mosquito.

Often disease symptoms do not appear until years after infection. The disease can permanently damage the lymph system and kidneys. Because the lymph system does not work right, fluid collects and causes swelling in the arms, breasts legs, and, for men, the genital area; the swelling can be up to several times the normal size. The swelling and the decreased function of the lymph system make it difficult for the body to fight germs and infections. A person with the disease tends to have more bacterial infections in the skin and lymph system.

LF is a leading cause of permanent and long-term disability worldwide. People with the disease can suffer pain, disfigurement, and sexual disability. Affected people frequently are unable to work because of their disability. Poor sanitation and rapid growth in tropical and subtropical areas, where the disease is common, has created more places for mosquitoes to breed and has led to more people becoming infected.

The Solution:

LF has been earmarked for elimination by the year 2020 through mass drug administration (MDA) with the combination therapy of albendazole/DEC or albendazole/ivermectin.

The strategy rests on the hypothesis that in an area where the vector species transmitting the parasitic worms are Anopheles mosquitoes, it is feasible to eliminate LF using MDA because of the inability of Anopheles species to transmit low-density worm larvae. This assertion may not always be true due to the species diversity of Anopheles vectors transmitting these parasitic worms. In situations where vector species can transmit low level worm larvae, there will be the need for some vector control to complement MDA if LF elimination is to be achieved. Blanket vector control using insecticides can have serious impact on non-target organisms leading to loss of biodiversity without achieving control goals in the long term. Thus effective vector control will require identification and characterization of the vectors, their ability to transmit low-density worm larvae, their distribution and the environmental factors that influence breeding and abundance.

Global Impact:

The project will contribute to the development of specific targeted vector control strategies to compliment the use of drugs administration for the elimination of lymphatic filariasis in Ghana and eventually through collaborative work in other countries where An. gambiae s.l. and An. funestus are the major vectors. At the institutional level, the project will build capacity in bioinformatics and GIS. Also it will create an increased awareness in local communities on lymphatic filariasis and its control. The global and regional impacts will be the provision of specific databases for control programs in LF endemic areas and placing of vector diversity in the overall context of biodiversity issues. This could lead to policy and programmatic changes in the control of many vector borne diseases.