Preventive chemotherapy (PC) is a cornerstone in the fight against NTDs. PC is defined as large-scale delivery of safe, quality-assured medicines, either alone or in combination, at regular intervals to entire population groups. WHO recommends PC against the 5 NTDs that are the focus of this report: lymphatic filariasis (LF), onchocerciasis, schistosomiasis, soil-transmitted helminthiases (STH) and trachoma. PC is also used for other NTDs, including food-borne trematodiases, taeniasis and yaws, for which the PC approach is currently implemented on a much smaller scale. Other interventions (case management, vector control, veterinary public health and WASH) may also be required for the control, elimination and eradication of each of these NTDs.
PC represents a major public health intervention, delivering over 1 billion treatments every year, providing essential care for people at risk of infection and the associated diseases. In 2019 alone (latest reporting year for which data collection is complete), 1.795 billion treatments were delivered to 1.155 billion individuals in need of PC for at least 1 of the 5 NTDs listed above.
WHO Member States submit reports on annual progress in control and elimination interventions relevant to these diseases. Table 2 summarizes data on implementation of PC in 2020 by WHO region, as received at WHO by 15 September 2021. It also provides the results of an analysis of the numbers of people requiring and receiving PC in 2020. These numbers are updated annually from the most recent epidemiological data for the targeted diseases generated by programmes and from demographic information that reflects updated population figures at implementation unit level. Analyses have been carried out to determine the geographical overlap of the different diseases targeted by PC.
In 2020 many countries reported major disruptions in implementation of mass drug administration (MDA) campaigns due impact of COVID-19. In the pulse surveys conducted by WHO in May-July 2020 and January-March 2021, 60% of countries reported that implementation of large-scale MDA campaigns had been at least partially disrupted, with 37% of those countries reporting severe disruption to these efforts. Based on reports submitted to WHO, many countries cancelled or postponed 2020 MDA campaigns. In some countries the planned MDA rounds were implemented partially, which results not achieving the target coverage for the diseases.
Reports for 2020 from several countries have not yet been submitted to WHO or currently under review. Data received from these countries will be available in the WHO Global Health Observatory.9 Detailed reports on the control and elimination of specific diseases will be published in subsequent issues of the Weekly Epidemiological Record.
In 2020, 62 countries reported on implementation of PC for 1 of the 5 diseases, and within those countries, 732 million individuals received treatment for at least 1 disease; 344.6 million were treated for LF, 94 million for onchocerciasis, 429 million for STH, 66.1 million for schistosomiasis and 32.8 million for trachoma. During MDA campaigns in 2020, 1.081 billion treatments were distributed.
* In the African Region, 41/45 (91%) countries required PC for [greater than or equal to] 2 diseases,...