Written by Dr. Samuel Akpan
Zoonoses are diseases that are transmissible between humans and animals and vice-versa. According to a World Health Organization (WHO) report, over 75% of emerging infectious diseases are traceable to pathogens from animals. Pathogens are gradually evolving, with changes in genomic structure and host specificity. This has raised concerns over the future ability of physicians to treat infections and the reduced potency of currently used antibiotics against current and rapidly evolving pathogens.
Zoonotic diseases can be classified in 4 ways viz:
- Classification based on causative agent eg viral zoonoses (avian influenza, SARS, etc), bacterial zoonoses (Tuberculosis, Brucellosis, etc), fungal zoonoses (Candidosis, aflatoxicosis, etc), and parasitic zoonoses (taeniasis, trichinosis, etc).
- Classification based on clinical signs eg hemorrhagic zoonoses such as Ebola, Crimean-Congo, or encephalitic (eg Rabies, Leptospirosis).
- Classification based on life cycle and direction of transmission eg direct zoonoses, indirect zoonoses, zooanthroponoses, anthropozoonoses, etc.
- Classification based on a combination of 2 or 3 above eg. Viral hemorrhagic diseases (tick-borne encephalitis, etc), bacterial encephalitic zoonoses (Leptospirosis, etc)
The World Zoonoses Day, celebrated globally on July 6, signifies a lot for global health. First, it is the day in 1885 when the first rabies vaccine was administered to a boy to protect against the rabies virus. Secondly, it represents a day the whole world should reminisce about the importance of paying attention to zoonoses. It is pertinent to note that zoonoses have proven to be much more than a health sector problem. It has assumed the status of an economic meltdown determinant. It is a health problem with a social face. With recurrent pandemics, a bold statement has been made that zoonoses are not just an issue calling for attention by state and federal ministries/departments of health, but rather a global phenomenon, with devastating effects on livelihoods, national and international economies. Zoonotic diseases, past and present, have proven to be more of socioeconomic importance. For example, the World Bank (2016) states that the epidemic outbreaks of Ebola hemorrhagic fever (EBF) in West African countries of Guinea, Sierra Leone, and Liberia have overturned most of the economic gains of their pre-Ebola years. Up until the epidemic (2014/2015), these countries were among the fastest-growing economies in the world. This demonstrates the far-reaching impacts of zoonoses outside of the health impact.
With the COVID-19 global standstill as a case study, this year’s World Zoonoses Day is a call for sober reflection on how massive urbanization efforts have impacted negatively on nature and environmental integrity; how corruption, poor leadership, and myopic policy thrusts have been a clog in the wheel of efficient infectious disease surveillance and provision of healthcare infrastructure; how the neglect of wildlife conservation can spur undesirable consequences on international tourism, trade, and travels, with huge loss of foreign exchange; how insufficient funding of universities and research institutes has barred research innovation, vaccine and drug discoveries in developing countries; and how lack of cross-sectoral One Health collaboration has retarded global infectious disease control efforts.
Currently, a cursory look around reveals a myriad of potential time-bombs, new zoonotic infections waiting to happen. It is visible in the unhygienic abattoirs, the wet clustered market places, the poor sanitary living conditions, the lack of access to clean water, the ripped off green cover of hitherto forest reserves (former fortresses for wildlife, reservoirs of potential zoonotic pathogens), the open waste dumps, the polluted marine waters, the poorly equipped research and diagnostic centers, and the irresponsive national governments.
With constant threats to global food security, business, tourism, education, animal and human life, the subject of zoonoses cannot be swept under the carpet; not more so in the next decade. It is time for an emergency world congress on zoonotic diseases, with national presidents, researchers, international animal and human health bodies, prominent individuals, agencies, and community-based institutions in attendance, to fashion out multisectoral inclusive ways to prevent and curtail further outbreaks. Previous topical research findings, models, retrospective, and Spatio-temporal studies should be utilized to predict and structure emergency response to impending outbreaks. Countries should be supported by intrinsically and extrinsically to build and maintain quality health infrastructure and strengthen their systems. More budgetary allocations should be made by national governments and donor agencies for zoonotic disease surveillance, prevention, and control activities. A coalition of international and regional governments should take proactive attempts at environmental recovery. This is the way to go, for a healthy world, to contribute to the realization of United Nations (UN) Sustainable Development Goals (SDGs), as well as achieving the international and national health and economic goals.