Global trends in neglected tropical disease control and elimination: impact on child health

Abstract

The neglected tropical diseases (NTDs) are a group of 17 lesser known chronic infections which predominantly affect poor and disenfranchised communities. There are a number of NTDs that cause significant global morbidity in children, including the three major soil transmitted helminth (STH) infections (ascariasis, trichuriasis and hookworm infection), schistosomiasis and trachoma. These NTDs, together with lymphatic filariasis and onchocerciasis, are currently being targeted for global control and elimination through mass drug administration (MDA) campaigns. They represent the most common NTDs and share significant geographical overlap. Additionally, many individuals are polyparasitised with more than a single NTD. Integrated NTD control and elimination MDA programmes offer safe and efficacious treatments for all seven NTDs. However, the current global level of MDA coverage for the leading childhood NTDs, that is, STH infections, schistosomiasis and trachoma, remains well under 50%. Limiting factors for global coverage include insufficient global financial support, drug donation capacity of pharmaceutical companies and targeting school age children to the exclusion of other age groups in need of treatment, such as preschool age children. There is also a need for development of novel prevention and treatment modalities, such as next-generation small molecule drugs and vaccines. Efforts are underway to harness the momentum of a 2012 London Declaration on NTDs and a 2013 World Health Assembly (WHA) resolution as a means to control or in some cases eliminate by 2020 these NTDs that affect children worldwide.

Cross-species prophylactic efficacy of Sm-p80-based vaccine and intracellular localization of Sm-p80/Sm-p80 ortholog proteins during development in Schistosoma mansoni, Schistosoma japonicum, and Schistosoma haematobium

“…Over 240 million people are estimated to be currently infected worldwide with the majority being school aged children (Barry et al 2013; Molehin et al 2016). Experts in the field believe that the current estimate of the burden of schistosomiasis is most likely between 400 and 600 million (Hotez et al 2014).…”

Helminth Infections

“…28 If confirmed, female genital schistosomiasis could emerge as one of the most common gynecologic conditions in sub-Saharan Africa. 12 Additional evidence from two epidemiologic studies conducted in Zimbabwe and Tanzania indicates that female genital schistosomiasis is linked to a 2.9-fold and fourfold increase in risk of acquiring human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS), respectively. 27,29,30 It is believed that highly vascular and CD4+ cell-enriched sandy patches in the cervix or elsewhere in the female genital tract may provide host entry routes for sexually transmitted HIV, although other mechanisms are plausible.…”

Rationale for the Coadministration of Albendazole and Ivermectin to Humans for Malaria Parasite Transmission Control

“…95,96 However, sustainable control of STHs is not possible with a single MDA because of high reinfection rates due to the fact that eggs and/or larvae present in soil are not affected by treatment of humans. 97,98 Although MDAs can have an immediate impact on STH prevalence rates, 99,100 reinfection of STHs can occur within 6-9 months post-MDA depending on a multitude of factors, including previous STH prevalence in an area, sanitation infrastructure, community personal hygiene standards, and efficacy of albendazole for the treatment of trichuriasis and hookworm. [101][102][103][104] As stated previously, ivermectin MDAs for Plasmodium transmission control in many endemic areas will have to be performed repeatedly during malaria transmission seasons to have a sustained impact on Plasmodium transmission.…”