Clinical Trial: Mass Drug Administration for Lymphatic Filariasis and Onchocerciasis for Liberia

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Observational

Official Title: Optimization of Mass Drug Administration With Existing Drug Regimens for Lymphatic Filariasis and Onchocerciasis for Liberia

Brief Summary:

Approximately 5,200 people will participate per year. The study population will include females and males over 5 years of age who live in filariasis and onchocerciasis endemic areas. Subject selection will not be based on health status.

Two sites will be studied, and each study will last for 4 years. Participants will be studied only once in cross-sectional surveys. Some subjects may be included in more than one annual population survey, but this is not a longitudinal study.

Investigators will compare annual and semiannual mass drug administration (MDA) for lymphatic filariasis and onchocerciasis, and investigators will compare the impact of these MDA schedules on soil transmitted helminth infections. MDA will be administered by others (Liberian Ministry of Health or Liberian Institute of Biomedical Research).

The investigators will test the hypothesis that semiannual mass drug administration (MDA) is superior to annual MDA for elimination of lymphatic filariasis, onchocerciasis and for control of soil transmitted helminth (STH) infections.

  1. Compare the relative impact and cost effectiveness of annual vs. twice yearly mass drug administration (MDA) for elimination of lymphatic filariasis (LF) in these populations.
  2. Compare the relative impact and cost effectiveness of annual vs. twice yearly mass drug administration (MDA) for elimination of onchocerciasis in these populations.
  3. Study the impact of annual vs. semiannual MDA on soil transmitted helminth (STH) infection in these populations.

Detailed Summary:

Lymphatic filariasis (LF) is a deforming and disabling infectious disease that causes elephantiasis and genital deformity (especially hydroceles). The infection affects some 120 million people in 81 countries in tropical and subtropical regions with well over 1 billion people at risk of acquiring the disease [1]. LF is caused by Wuchereria bancrofti and Brugia spp. (B. malayi and B.timori), nematode parasites that are transmitted by mosquitoes. This study is based on the assumption that currently used MDA regimens and schedules are not optimal for achieving elimination of LF. These regimens (either annual Albendazole (Alb) 400 mg plus diethylcarbamazine 6 mg/kg or Alb 400 mg plus Ivermectin (Iver) 200 µg/kg for LF) were introduced more than 10 years ago.

Onchocerciasis ("Oncho") is similar in some ways to LF in that it is a vector-borne nematode parasitic disease that causes severe disability. In contrast to LF, this disease causes blindness and severe skin disease rather than elephantiasis, and it is spread by black flies instead of mosquitoes. O. volvulus adult worms live in subcutaneous nodules while the adult worms of the LF parasites live in lymphatic vessels. O. volvulus adult worms are larger and less sensitive to available drug treatments than those of the species that cause LF and have a longer lifespan (approximately 14 years rather than the estimated 7 years for LF parasites). More effective drugs or dosing schedules for MDA against Oncho could shorten the number of years needed to interrupt Oncho transmission in areas that previously had high disease rates.

Drugs used for LF MDA are also active against soil transmitted helminth infections (STH, e.g., Ascaris, Hookworm, and Trichuris). De-worming campaigns using anthelmintics usually target special groups of the population, such as schoolchildren,
Sponsor: Washington University School of Medicine

Current Primary Outcome: Microfilaria prevalence based on results of microscopic examination of blood smears and skin snips. [ Time Frame: 4 years ]

From annual population based surveys, the prevalence of microfilaremia (filarial parasites in the blood or skin snips) will be assessed by microscopic examination of slides with thick blood smears and skin snips. Test results for individuals are either positive or negative. The unit for prevalence studies is the percentage (%) of individuals with positive tests.


Original Primary Outcome: Same as current

Current Secondary Outcome: Prevalence of filarial antigenemia in blood and intensity of filarial and intestinal worm infections based on results of microscopy. [ Time Frame: 4 years ]

Secondary outcomes for the study include prevalence of filarial antigenemia (detected with the Binax Filariasis Now card or Filariasis Test Strip tests) and prevalence of worm eggs in stool detected by the Kato-Katz test. Both of these outcomes are qualitative with no units of measure (positive or negative). Other secondary outcome measures will be intensity of infection by counting microfilaria (Mf) in blood (Mf per ml of blood) and counting Mf in skin (Mf per milligram) and by counting worm eggs (eggs per gram of stool, assessed separately for each parasite species). All of these quantitative assessments are based on counting parasites by microscopy.


Original Secondary Outcome: Prevalence of filarial antigenemia in blood and intensity of filarial and intestinal worm infections based on results of microscopy. [ Time Frame: 4 years ]

Secondary outcomes for the study include prevalence of filarial antigenemia (detected with the Binax Filariasis Now card test) and prevalence of worm eggs in stool detected by the Kato-Katz test. Both of these outcomes are qualitative with no units of measure (positive or negative). Other secondary outcome measures will be intensity of infection by counting microfilaria (Mf) in blood (Mf per ml of blood) and counting Mf in skin (Mf per milligram) and by counting worm eggs (eggs per gram of stool, assessed separately for each parasite species). All of these quantitative assessments are based on counting parasites by microscopy.


Information By: Washington University School of Medicine

Dates:
Date Received: July 12, 2013
Date Started: March 2012
Date Completion: September 2017
Last Updated: November 21, 2016
Last Verified: November 2016