Earlier, people believed illnesses resulted from imbalances in the body and supernatural powers. Studies held by biologists revealed that diseases resulted from such microorganisms as viruses, fungi, and bacteria (Ewald, 1996). Evolution of infectious diseases has led to the emergence of new disorders that were previously absent in the community or an upsurge of incidence or widened the geographic coverage of the disease. Genetic variation has been responsible for viral evolution, drug resistance, and microbial variance changing the trends of infectious disease development. However, other factors like environmental, ecological, and demographic factors facilitate the development of new illnesses. The newest infectious diseases include Lyme disease, hemolytic uremic syndrome, hantavirus pulmonary syndrome, human immunodeficiency virus (HIV), and acquired immune deficiency syndrome (AIDS) (Tibayrenc, 2011).The government has implemented various strategies that have had decreased the outbreaks of infectious diseases. It has strengthened its surveillance and response to emerging infectious diseases. This approach has enabled early detection and monitoring of the pathogens, diseases they cause, and factors that influence their emergence. Hence, it has improved responses to emerging diseases. Moreover, the government has facilitated applied research on these illnesses by use of modern laboratory techniques and electronic communications. This research has enabled identification and understanding of the emerging diseases. Through the improvement of public health infrastructure and training, the government has been able to enhance the nation’s capacity to respond to complex disease threats and provide training opportunities in the diagnosis and treatment of these emerging infections. Additionally, it has also participated in the support and implementation of programs for the prevention and control of emerging infections (Centers for Disease Control and Prevention, n.d.).
The three types of pathogens are bacteria, viruses, and fungi. Bacteria are single-celled microorganisms that are prokaryotic (DNA is not enclosed in a nucleus). They are divided into five groups based on their shapes: rod (bacilli), comma (vibrio), spherical (cocci), spiral (spirilla), and corkscrew (spirochetes). Fungi, on the other hand, are eukaryotic (DNA material is found in a nucleus). They can be single-celled or multicellular and are larger than bacteria and viruses (American Society for Microbiology, n.d.). They are divided into three major groups: single-celled microscopic yeasts, macroscopic filamentous fungi that produce fruitful bodies (for example, mushrooms), and multicellular filamentous molds. Viruses are the smallest microbes and are neither eukaryotic nor prokaryotic. They depend on other living organisms for their survival (host) and are non-living outside their hosts.
Summarily, infectious diseases cause many detrimental effects including death. Earlier, people believed that diseases resulted from such causes as imbalances in the body and supernatural powers. Evolution of infections led to the emergence of new diseases such as HIV/AIDS. Such factors as genetic variation, drug resistance, environmental, ecological, and demographic issues have resulted in the evolution of infectious diseases. Various government strategies have reduced these illnesses outbreaks. They include improved surveillance and response, applied research, improvement of public health infrastructure and training, and implementation of prevention and control programs. The three types of pathogens include bacteria, fungi, and viruses, and each type of them has its properties that differentiate it from the other kinds of pathogens including the sizes.