The global recognition of the importance of this approach in also reflected in the G20 Rome Declaration from the recent Global Health Summit, held in May 2021 . The locution of One Health is undoubtedly not novel to parasitologists, who, by vocation, study infections and their causative agents and hosts, at the interface with human and veterinary medicine. With special regards to parasitic conditions, Africa harbours a plethora of them that require to be addressed according to the One Health approach, due to the dependence of parasites and their potential vectors or intermediate hosts on numerous environmental factors , habitat conditions such as temperature, humidity, availability and type of waters , etc.. For instance, malaria, the parasitic disease par excellence of the African continent, provides a compelling example of a condition that needs to be tackled through One Health efforts, due to the zoophilic behaviour of several competent mosquito vectors .
This is the approach taken by recent investigations aiming at treating cattle and other livestock with ivermectin or macrocyclic lactone-based “endectocides”4 in order to reduce the fitness of competent malaria vectors feeding on them . Similarly, the application of pyrethroid-based insecticides or arthropocides to cattle not only aims to control livestock-specific ectoparasites but also to reduce populations of zoophilic mosquitoes responsible for malaria transmission . These methods could be considered as complementary tools that could help reduce malaria incidence in a given area, although alone they may not suffice to eradicate the disease. It is nonetheless essential that control campaigns consider all hosts on which competent mosquitoes feed and the outdoor component of malaria transmission. Other major parasitoses of the African continent are ascribed in the group of the so-called Neglected Tropical Diseases , of which Africa bears ~40% of the world’s burden . These are typical diseases of poverty, highly endemic in rural areas, not coincidentally where hygiene conditions and water sanitation are poor and where tight cohabitation between humans and animals occur .
Out of the 20 NTDs recognised by the WHO, 19 occur in Africa, with 11 of them being of parasitological aetiology. Of these, at least seven include zoonotic agents . Although not involving a parasitic causative agent, NTDs like dengue and chikungunya still require parasitic arthropods as vectors , further highlighting the relevance of parasitological and entomological expertise in the study, management and control of most NTDs in Africa and elsewhere .Undoubtedly noteworthy in the area of One Health are also the so-called Neglected Zoonotic Diseases , that are deemed as “neglected” due to under-reporting on their occurrence, leading to an underestimation of their relevance to policy-makers and donors . The NZDs comprise a subgroup of NTDs , all of which except rabies are of parasitic aetiology. Currently, rabies, echinococcosis, foodborne trematodiases and taeniasis/cysticercosis are considered as priority NZDs by the WHO Department of Control of NTDs ; the fact that three of them are parasitic infections further highlights the topicality and heavy burden of parasitesin the realm of zoonoses. In addition, zoonotic causes of non-malarial febrile illnesses such as anthrax, brucellosis and leptospirosis are also recognised by the WHO to be of growing importance and are therefore monitored accordingly . The control of NTDs is a fifirm component of the UN 2030 Agenda for Sustainable Development, as reflflected in its Sustainable Development Goal target 3.3 aiming, by 2030, to “end the epidemics of AIDS, tuberculosis, malaria and NTDs ” .
In the past decade, some substantial progress was made in these regards, with 31 countries having succeeded in eliminating at least one NTD, eight of them being in Africa. However, despite these results, many of the targets set by the WHO in the 2020 roadmap were not met, in Africa and other endemic regions . In particular, the overall control of NTDs was negatively affected by the disruptions caused by the COVID-19 pandemic in the year 2020, with major hindrances being recorded in the delivery of health services . Accordingly, a new NTD roadmap was defined for the period 2021–2030, identifying critical gaps and actions required in order to prevent, control, eliminate or eradicate the 20 target diseases and disease groups . Importantly, the new agenda fully acknowledges the value of adopting an integrated One Health strategy for NTDs, promoting stronger multisectoral collaborations among agriculture, livestock, wildlife, environment, food safety, health and other ministries . Such a strategic development derives from the consideration that all zoonotic NTDs, in order to be fully controlled in human populations, need to be managed appropriately and possibly synergistically in animal hosts and/or reservoirs. Notably, tackling NTDs involving livestock species in their epidemiology , can provide dual benefifits in terms of human and economic development, by reducing risks of zoonotic infections, on one hand, and improving communities’ livelihood, through better animal health and productivity, on the other .