The Risk of Infectious Disease Emergency and its Exponential Spread still stand

  

Today globally, there is continuous unprecedented ecological change, with dramatic reductions in natural ecosystems and biodiversity and equally dramatic increases in people and domestic animals. These, together with climate change, increase the risk of disease emergencies.

This article explains some of the reasons why the risk of outbreak and rapid spread of a new infectious disease still stand inevitable in many communities.

Change in human behavior

Due to modernization, urbanization, traveling, migration, conflict, wildlife trade, conflicts, change in dietary preference, and globalization, the risk of emergence and transmission of infectious has become very high globally.  

Conflicts cause population displacement which makes many people, including highly vulnerable populations to be exposed to pathogens in the bush. Wildlife trade, on the other hand, makes dealers get exposed to pathogens on animals’ body or their products if necessary precautions are not followed. The outbreak of West Nile Fever in the United States of America was attributed to wildlife trade and animal migration

The climatic change

Today, climate change is a concern in every part of the world where it is known to have brought problems in all sectors of development. However, it also has an influence on disease distribution in various parts of the world. Climate change influences emergency of the new diseases because it influences the environmental conditions that may favor or disfavor survival, reproduction, abundance, and distribution of pathogen, vectors, and host which are important in disease transmission. For example in the case of plasmodium spp, abundant rainfall, high temperature, and high humidity favor its growth and survival.

Change in animal or human host

With zoonoses, direct transmission from wild animals to humans is rare but the gap has been bridged by domestic animals. Therefore the risk of transmission is increased by the increase in the livestock population and demand for their products among the growing population of developing countries like Uganda.

In addition, increased livestock production also increases the use of fertilizers as fodders or feed and more livestock wastes are generated subsequently, which create a nutrient-rich environment that supports the growth and proliferation of many pathogenic microbes with the potential of causing new diseases.

Change in pathogens themselves

This occurs naturally when the pathogens evolve to exploit new hosts or adapt to changes in evolutionary pressure. This is seen in antimicrobial resistance where pathogenic microbes are not killed or inactivated by common modern medicine.

Environmental changes

This is highly attributed to human activities which involve encroachment on the natural ecosystem, hence causing loss of natural integrity of the ecosystem. The integrity of the ecosystem helps in the regulation of pathogen species by ensuring species diversity that makes it hard for one species to dominate or spread rapidly in the natural ecosystem. Such difficulty in spread or domination by single species is brought about by interspecific competition in the undisturbed ecosystem. 

Such activities that disturb the ecosystem are continuously being practiced in Uganda with less concern by stakeholders. There are environmental laws and regulations to regulate environmental activities but less effort is put into implementation.

Way forward. There is an urgent need for strengthening the national health system, regulations, and effective disaster and emergency preparedness plan in each country so that this risk is reduced otherwise, the addition of potentially virulent infectious diseases in the global community will be inevitable and will worsen the effects that covid-19 has brought on the already constrained health system, especially in developing countries.

Author: Ivan Ongebo, Bsc. Environmental Health Scientist at Makerere University School of Public Health