by Raphaël Zellweger and Aerie Em

The externalities of the COVID-19 pandemic

In 1962, virologist and Nobel Prize winner Sir Frank Macfarlane Burnet famously said, “To write about infectious diseases is almost to write of something that has passed into history.” Nearly 60 years later, there is no doubt that we are fighting the most disruptive infectious disease outbreak since the Spanish flu in 1918. As we all wonder if we will ever again leave the house without a mask, wide-spread “pandemic-fatigue” is only alleviated by the hope of a vaccine. But could there be other cause for hope?

Rising global COVID-19 cases have remarkably coincided with a reduction in other respiratory and gastrointestinal diseases. In Taiwan, for example, infection rates for influenza, pneumonia, enterovirus and scarlet fever were lower in 2020 compared to previous seasons [1]. It is reasonable to attribute this phenomenon to COVID-induced hygiene consciousness and behavioral changes such as handwashing, mask wearing and social distancing. Unsurprisingly, this reduction has not been observed for vector-borne diseases, as their mode of transmission and control typically differ from respiratory illnesses like the flu and COVID-19. For instance, several countries including Singapore, Peru, Brazil and Colombia suffered epidemics of dengue, a virus transmitted by mosquitoes, during the COVID-19 pandemic [2].

While the quasi-universal COVID-19 prevention measures have helped reduce the burden of some diseases, the pandemic has had a detrimental effect on the prevention, control, and treatment of many other illnesses. With all eyes and resources focused on COVID-19, health systems are on the brink of collapse and other disease programs have been de-prioritized. Rightfully designed to limit the spread of COVID-19, lockdowns and restrictions on mobility have gravely hindered health delivery services. According to the US CDC, measles vaccination campaigns have been delayed or interrupted in over 40 countries, putting millions of people at risk of missing their measles jab [3].

The residual impact of COVID-19 on Neglected Tropical Diseases (NTDs)

The prioritization of COVID-19 control has been particularly bad news for neglected tropical diseases, a set of around 20 diseases thus named for rarely appearing in the global health spotlight. Although they affect approximately 1 billion people in some of the poorest and most marginalized regions across more than 140 countries in Asia, Africa and the Americas, NTDs—which include diseases such as Schistosomiasis, Guinea Worm Disease and Lymphatic Filariasis—have historically received less funding compared to diseases such as HIV, malaria and Tuberculosis (TB). However, the last two decades have seen a surge in NTD research and advocacy, gaining momentum and tremendous progress toward control and elimination. Most notably, earlier this month, the World Health Organization (WHO) launched a new road map to “end the neglect” of NTDs and achieve global targets for the next decade [4].

Although these milestones are encouraging and a major step forward to improve the lives of a significant portion of the world’s population, the COVID-19 crisis threatens to jeopardize future progress for NTD control [5, 6]. An obvious example is human resource attrition with most health workers shifting to critical COVID-19 activities, severely restricting implementation of NTD control programs. Delay or interruption of treatment interventions such as mass drug administration (MDA) due to restrictions in mobility or disruption in drug supply has been frequent, potentially resulting in increased disease transmission.

In Malawi, for instance, a recent outbreak of Schistosomiasis, a poverty-associated disease caused by parasitic worms, is likely to go unchecked due to COVID-related cancellation of MDA [7]. This is particularly damaging to Schistosomiasis control efforts as there is not yet an approved vaccine to prevent this debilitating disease. Together with access to clean water and improved sanitation (WASH), education and vector control, MDA campaigns are instrumental to alleviating painful symptoms and limiting Schistosomiasis spread. Most of these interventions are included in the SOMA project, a Schistosomiasis prevention and control program in Madagascar led by the International Vaccine Institute.

Furthermore, the redistribution of health resources has impacted production of essential equipment. Many NTD control programs heavily rely on rapid diagnostic tests (RDTs) to identify and treat cases. But in the era of COVID-19, most RDT manufacturers have shifted resources towards urgently needed COVID RDTs, leaving production of RDTs for other diseases momentarily on the backburner [8].

An adjusted global health agenda and the way forward

While the COVID-19-ridden landscape is currently “the new normal,” there might be lessons to learn, and reflecting on the pandemic might eventually benefit the fight against NTDs [5]. To begin with, current infrastructure for NTD control was important groundwork for the COVID-19 response. The WHO recommends that local health authorities “use existing NTD platforms, surveillance mechanisms and WASH/health education opportunities to support implementation of COVID-19-related measures, as appropriate” [9]. How does this work? In many low- and middle-income countries (LMICs), MDA programs for NTDs have historically been supported by community health workers who represent essential human resource capital at the periphery of formal health systems [5].

With their capacity for rapid mobilization, community health workers—who are largely trusted by the communities they serve—are able to convey public health messages necessary to curb the spread of COVID-19 and raise awareness about disease transmission [5]. In addition to the deployment of effective communication channels, COVID-testing itself could be integrated into existing NTD programs, taking advantage of a well-oiled system already in place.

Inversely, the philosophy of large-scale testing adopted for COVID-19 control could be an inspiration to strengthen testing for some NTDs as we strive towards control and elimination. Additionally, in an era where digital technology is virtually everywhere, COVID-19 has revealed smartphone apps as promising tools to instantly disseminate public health messages, identify and follow-up on potential cases, and assist with contact tracing. With increasing smartphone use and internet connection in many regions of the world, these technologies may very well soon find their place in NTD surveillance programs.

COVID-19 has affected just about every areas of daily life, and control programs for NTDs are no exception. Activities have been postponed or paused with consequences that will vary depending on the disease [10]. When surveillance and control can safely resume, we need to develop synergies between NTDs and COVID-19 prevention. One day, the COVID-19 pandemic will perhaps pass into history. But until that day, let some of the pandemic lessons assist us in the battle against NTDs as we aim for a future free of infectious diseases.

References

1. Lee, H.H. and S.H. Lin, Effects of COVID-19 Prevention Measures on Other Common Infections, Taiwan. Emerg Infect Dis, 2020. 26(10): p. 2509-2511.
2. Sarkar, S., P. Khanna, and A.K. Singh, Impact of COVID-19 in patients with concurrent co-infections: A systematic review and meta-analyses. J Med Virol, 2020.
3. CDC. COVID-19’s Impact on Measles Vaccination Coverage. 2020 [cited 2021 January 18]; Available from: https://www.cdc.gov/globalhealth/measles/news/covid-impact-on-measles-vaccination.html.
4. WHO. Eliminating NTDs: together towards 2030 – Formal launch of the new road map for neglected tropical diseases. 2021 [cited 2021 January 22]; Available from: https://www.who.int/news-room/events/detail/2021/01/28/default-calendar/eliminating-ntds-together-towards-2030-formal-launch-of-the-new-road-map-for-neglected-tropical-diseases.
5. Molyneux, D.H., et al., COVID-19 and neglected tropical diseases in Africa: impacts, interactions, consequences. Int Health, 2020. 12(5): p. 367-372.
6. Adepoju, P., NTDs in the time of COVID-19. Lancet Microbe, 2020. 1(6): p. e244.
7. Kayuni, S.A., et al., An outbreak of intestinal schistosomiasis, alongside increasing urogenital schistosomiasis prevalence, in primary school children on the shoreline of Lake Malawi, Mangochi District, Malawi. Infect Dis Poverty, 2020. 9(1): p. 121.
8. de Souza, D.K., et al., Diagnosis of neglected tropical diseases during and after the COVID-19 pandemic. PLoS Negl Trop Dis, 2020. 14(8): p. e0008587.
9. WHO. Control of Neglected Tropical Diseases. 2020 [cited 2021 January 18]; Available from: https://www.who.int/teams/control-of-neglected-tropical-diseases/overview/ntds-and-covid-19.
10. Toor, J., et al., Predicted Impact of COVID-19 on Neglected Tropical Disease Programs and the Opportunity for Innovation. Clin Infect Dis, 2020.