Emerging and Infectious Diseases
"Emerging" infectious diseases may be defined as infections that have newly occured in a tremendously population. Among recent examples the most common example is covid 19 and others are HIV/AIDS, hantavirus pulmonary syndrome, zoonosis, and hemolytic uremic syndrome (a foodborne infection caused by certain strains of Escherichia coli). Specific factors precipitating disease emergence are often identified in virtually all cases. These include ecological, environmental, or demographic factors that place people at enlarged contact with a previously unaware microbe or its natural host or promote dissemination. These factors are increasing in prevalence; this rise, together with the continued evolution of viral and microbial variants and selection for drug resistance, suggests that infections will still emerge and doubtless increase and emphasizes the urgent need for effective surveillance and control.