Finding realistic solutions to NTD target delays.

Every year since 2016, more than 1 billion individuals have been reached with public health interventions to control neglected tropical diseases (NTDs). In 2020 and 2021, however, due to the disruptions caused by the COVID-19 pandemic to health services, the number of individuals reached by these interventions dropped significantly.1, 2

In The Lancet Global Health, Anna Borlase and colleagues report on a study conducted by applying mathematical transmission models with the aim of evaluating the negative impact of the COVID-19 pandemic on activities for the control of seven NTDs (soil-transmitted helminthiases, schistosomiasis, lymphatic filariasis, onchocerciasis, trachoma, visceral leishmaniasis, and human African trypanosomiasis). The authors also discuss the consequences of these disruptions for NTD prevalence or incidence and propose some mitigating measures to be taken to avoid delays in the attainments of the 2030 targets set by the WHO NTD road map.

As expected, the models consistently predict a delay in reaching the 2030 targets that is more significant in communities with higher endemicity. For most of the NTDs considered, the mitigating interventions proposed are feasible: they consist of conducting an additional round of mass drug administration, compensating for the one lost due to the pandemic, or enhanced case-finding. However, in the case of soil-transmitted helminthiases, the proposed solution is different: Borlase and colleagues propose to compensate for the one missed school round of benzimidazole distribution with one round of benzimidazole administration to the entire community. This recommendation may well be effective, but it is based only on infection transmission considerations. Notably, it does not take into account the associated cost, which is always an essential factor to consider in public health interventions for NTDs.

The cost of reaching an individual through a house-to-house drug distribution approach is, on average, five to ten times higher than that incurred by reaching a child through school distribution5, 6, 7 in which the school is used as support infrastructure and the drugs are distributed within each class by teachers at minimal cost. On the contrary, the house-to-house approach faces important costs due to the increased complexity of the activity and the need to recruit distributors.

In addition, since the mebendazole is proposed to be distributed to the adults as well, the total population to be targeted is approximately three times the number of the school children. Taking these very basic data into consideration, we can estimate that the proposed mitigation measure would cost between ten times (if children are reached by the school system and the adults by the house-to-house distribution) and 15 times (if children are also reached through house-to-house distribution) the cost of the missed round of school deworming. Considering that the control programmes for soil-transmitted helminthiases are normally running with few funds and a limited quantity of donated medicines, it is likely that neither resources would be sufficient to implement the proposed intervention.

It is our opinion that the formulation of recommendations on control interventions in the area of NTDs should also take into consideration programmatic aspects such as those mentioned above. In the case of soil-transmitted helminthiases, more frequent rounds of treatment with no expansion of the target population, as recommended for most of the other NTDs considered by the authors, could be a more practical solution than targeting adults. We would like to take this opportunity to invite Anna Borlase and colleagues to investigate whether the desired effect of the two approaches would be comparable or not.

This Comment reflects the views of the authors and not necessarily the views of WHO. We declare no competing interests.