Link between ecology and epidemiology

THE ESTIMATES of species losses are stupefying, several species will extinct in near future, about 140,000 species are lost each year, globally. It is pertinent to understand that what does humanity lose when global biodiversity is significantly reduced? The significant human problems caused by reduced biodiversity are: economic cost of lost biodiversity, reduced food security, more unpredictable weather, loss of livelihoods, losing sight of “nature”, and increased contact with infectious disease. The globalization and ecological disruption appear to be cause of new epidemiologic transition which is directly or indirectly associated with emerging and reemerging of infectious diseases. The urbanization trend, industrial revolution, and greater mobility have contributed significantly to trigger the disruption of biodiversity. There are clear changes in the type and dominance of emerging and reemerging infectious diseases which have occurred due to globalization and industrial revolution. The habitat destruction and biodiversity loss are fueling this condition. The connection between biodiversity loss and human health is getting very little attention in the accelerating life trends. The evidence of this connection is the spread of nonindigenous vectors and pathogens. It is appeared that the loss of predators and hosts that reduce pathogen transmission are also increasing the incidence of vector-borne illnesses. They live in an ecosystem which depends upon survival of healthy functioning and interactions with each other as well as other organisms. As a result the loss of biodiversity and ecosystem commotion has major impacts of emergence, transmission, and dissemination of many human infectious diseases. A recent study reveals that “habitat destruction and biodiversity loss, driven by the replacement of local species by exotic ones, deforestation, global transportation, encroaching cities, and other environmental changes can increase the incidence and distribution of infectious diseases in humans”. It is not new to think about biodiversity, but it is emerging to understand the link between species and land conservation as inherent to human health issues, the commencement of a trend to bring ecology and epidemiology together. At this stage, it is not affirmed that biodiversity loss is the primary force for emerging diseases but it appears to be playing a crucial role. Until now, no organization in Pakistan is putting questions of human infectious disease with reference to prevention of habitat structure and biodiversity in non-human species. By focusing in this direction on biodiversity loss, we can create a contrast between the natural ecosystems which are associated with greater biodiversity. The protective effect of greater species diversity on the risk of human infection has appeared in many diseases like malaria in the Amazon, East Africa, Thailand, and Indonesia, Nipah virus infections in Malaysia, Lyme disease or West Nile Virus (WNV) in the United States (also found in other parts of the world, especially Europe), Hantavirus infections in South Korea, and Schistosomiasis, and may be a common feature of many human vector borne diseases. Improved understanding of these causal mechanisms can inform decision makers on biodiversity conservation as an effective way to protect human health, as well as common person to protect themselves from infectious diseases.