CHANGING PATTERN OF DISEASES(EMERGING AND RE-EMERGING INFECTIONS) Presented by; Dr. Alteib Yousif Abdelgadir Student of Public and Tropical Health Master program - Patch 11 September 2012
Objectives Key terms Background Emerging and re emerging infections Potential contributing factors Control of infectious diseases Critical epistemology Emerging diseases and globalization Developing global response
By the end of this session, participants are expected to have some ideas about: Emerging diseases, key terms, history and potential contributing factors Control of infectious diseases Emerging diseases and globalization Developing global response
Emerging infections: An infection that has newly appeared in a population or has previously existed but has rapidly increasing in incidence or geographic range Population at risk: A population subgroup that is more likely to be exposed or is more sensitive to the infection than the general population Quarantine: The practice of isolating an individual who has or is suspected of having a disease, in order to prevent spreading the disease to others.
Infections remain a major global public health problem Humans originated in the tropical climate in Africa were affected by the same parasites as other primates in these areas. Humans as hunters moved to more temperate zones and the infectious agents they were exposed to changed due to new climate. In due time hunting gave way to agriculture and domestic animals living in close proximity to human...(opportunity for many zoonotic diseases) to spread to humans
Increase population size and density provided ideal conditions for further spread of person to person spread of infections Humans, food and water became reservoirs for many of these infections Trade routes became established and movement of people and goods carried new pathogens to susceptible populations
A climate of irrational fear has been a common feature of responses to infectious diseases for many centuries ( before and after the role of microorganism as a causative agents). Germ theory: Theory that all contagious diseases are cause by microorganism ( 1870) Control of infectious disease became through the work of Robert Koch and Louis Pasteur and the isolation and identification of the etiological agent
Nature of infectious diseases changing not only in magnitude but also inability of science to provide all answers because of: New disease notably HIV/AID, SARS Ancient and re-emerging diseases such as tuberculosis, diptheria ( these had disappeared in some parts of the world)
New agents are being implicated in the causation of a number of clinical syndromes; Parvovirus B19 (causes a childhood rash called fifth disease or erythema infectiosum which is commonly called slapped cheek syndrome) Herpes viruses; herpes type 1 (oral herpes) and herpes type 2 (genital herpes). HPV (warts, anal lesions, genital cancer, oro pharyngeal cancers, oral papillomas, etc
Many new drug resistant organisms, unresponsive to anti microbial agents have emerged over the last 60 years Multidrug resistant organisms such as M. Tuberculosis, Staph. Aureus and Salmonella species Bovine spongiform encephalitis decimated the British beef industry and cost $40 billion.
Population growth and Poverty: more than 2 billion suffer from under nutrition or malnutrition. Population movement ( 150million, 2.5%, people live outside their country of birth),more migrants live in overcrowded conditions Human behavior: Changes including sexual behavior and IV drug use
Non compliance by health care workers....drug resistance Technological development: Bovine Spongiform Encephalopathy (BSE; Mad Cow Disease) spread has been attributed to technological changes in animal and food chain dating back to the 1980s. BSE are transmissible Economic development and land use e.g malaria in newly agricultural area
Microbial adaptation and change...Antigenic shifts and drifts. Major epidemic are caused by antigenic drifts Breakdown of public infrastructure and public policy due to war or political change. Climate change: Vectors will be able survive in areas where they had not.
Warfare/ terrorism/conflict: British in 18th Century Distributed small pox infected blankets to North American Indians. Countries have sought to produce an Anthrax bomb and increasing concern about biological weapons
Involves going beyond the focus on host and organism to socioeconomic, cultural, and political necessary Globalization has challenged infectious diseases in a way that has become starker. The role of the state has become more important
Tension between the individual and the state: compulsory HIV test for employment and travel, compulsory immunization, Quarantine e.g H1NI. Many borders in African serve as semi- permeable membranes; open to disease and yet closed to cure.
What qualifies as emerging infectious diseases? Why do some persons constitute ‘risk group’ while others are ‘individuals’ at risk? Can standard epidemiology, (sometimes short on critical theory) help us to take hold of deep socio-economic issues relating to disease emergence?
Modern epidemiology is oriented to explaining and quantifying the bobbing of corks on the surface waters, while largely disregarding the strong undercurrents that determine where, on the average, the cluster of corks end up along the shoreline of risk’-McMichael 1995
Ancient trade route and early globalization WHO in 1948 became responsible for International Health Regulation, binding member states regarding cholera, plague, yellow fever and smallpox. (IHR has now been revised enhancing timeliness and reporting)
IHR does not provide legal framework for other diseases including threats of emerging diseases Enforcement of IHR depends on the cooperation of governments and there are no resources to ensure compliance such as punitive measures
Good health is both essential and instrumental to achieving human security’ (illness and death are critical threat to human life)-The Commission on Human Security. Violence, infections and poverty are the three health challenges that critically impact human security Bioterrorism The potential to cause mass casualty HIV/AIDS risk to population, military and peacekeepers... Uganda soldiers in Somalia
Development of global surveillance networks...surveillance remains fundamentally a local activity so collaboration is needed across borders International mechanism for control of infectious diseases depends heavily on government institutions While globalizations creates new risks it also offers new opportunities for enhancing communicable disease response e.g facilitating surveillance and reporting