INTERVENTIONS - PREVENTIVE CHEMOTHERAPY
The World Health Organization (WHO) recommends preventive chemotherapy (PC) (i.e. population-level treatment with safe, effective drugs) as the primary intervention to control morbidity from and transmission of soil-transmitted helminthiasis (STH). Mass drug administration of effective drugs to targeted populations at-risk has shown to effectively reduce STH prevalence and intensity of infection in targeted communities. Repeated PC with safe, affordable drugs at a recommended frequency helps lower STH prevalence and intensity of infection levels below those associated with morbidity.
The World Health Organization defines preventive chemotherapy for STH as the large-scale delivery of anthelminthic drugs, either alone or in combination, as a public health tool for preventing morbidity due to infection. WHO also notes that PC can reduce transmission. Preventive chemotherapy is the key intervention for STH. Different at-risk populations receive PC via different population-suitable platforms. Existing platforms for the at-risk populations including the following:
Effective PC campaigns target large portions of the population, reducing the lifespan of helminths in the host, the number of infected individuals, and the duration that they can excrete eggs into the soil. Therefore, effective PC campaigns also decrease the amount of infectious eggs (and the larvae resulting from eggs) in the soil, reducing the likelihood of continued transmission.
Mass Drug Administration (MDA) refers to the administration of drugs to targeted populations irrespective of infection status. Albendazole and mebendazole are the most common deworming medications. These medications have excellent safety profiles, are inexpensive, and are easily administered by non-medical personnel.
Certified preventive chemotherapy (PC) medication, donated by Johnson & Johnson and GlaxoSmithKline, are available free-of-charge to national Ministries of Health through the World Health Organization. See more information about these donations here.
Major Manufacturer: GlaxoSmithKline
Donation target (annual): 400 million tablets donated each year
Major Manufacturer: Johnson & Johnson
Brand name: Vermox®
Donation target (annual): 200 million tablets donated since each year
STH may seriously damage the health of children of 1 - 14 years old and women of childbearing age. Preventive chemotherapy (PC) coverage of these populations is critical to minimize morbidity associated with STH infections.
According to the World Health Organization, the treatment frequency for populations at-risk of STH is determined by a baseline prevalence estimate among school-age children. Experts continue to debate the appropriateness of relying on prevalence estimates of school children when trying to understand hookworm infection levels (since that parasite primarily infects adults). Repeated treatments help reduce and maintain levels of infection below those associated with morbidity.
Treatment: Case-by-case treatment is recommended
Treatment: Once a year treatment is recommended
Treatment: Twice a year treatment is recommended
FIND OUT MORE!
WHO STH Progress Report and Strategic Plan 2012
WHO: Pharmacopoeial standards
World Health Assembly Resolutions and Decisions
12. Ndibazza, J. et al. Effects of Deworming during Pregnancy on Maternal and Perinatal Outcomes in Entebbe, Uganda: A Randomized Controlled Trial. Clinical infectious Diseases. 50.4 (2010): 531–540. PMC.