Emerging and Re-emerging Infectious Diseases mmmmm Infectious Diseases CHP400 COMMUNITY HEALTH PROGRAM-II Emerging and Re-emerging Infectious Diseases mmmmm mmmmm Mohamed M. B. Alnoor mmmmm

Emerging and Re-emerging mmmmm Infectious Diseases mmmmm Contents mmmmm Definitions Emerging Infections since 1973 mmmmm mmmmm Major factors contributing to the emergence of infectious diseases

Definitions Emerging Infectious Diseases “New, reemerging Emerging and Re-emerging mmmmm Infectious Diseases mmmmm Definitions mmmmm Emerging Infectious Diseases “New, reemerging or drug-resistant infections whose incidence in humans has increased in the past two decades or threatens to increase in the near future.” mmmmm mmmmm

Definitions Emerging Infectious Diseases Emerging/New Emerging and Re-emerging mmmmm Infectious Diseases mmmmm Definitions Emerging Infectious Diseases mmmmm Emerging/New Newly appeared in a population. mmmmm Re-emerging/Resurging mmmmm Incidence increased over20 years or threatens to increase soon. Deliberately emerging: Developed for nefarious use

WHY are microbes still posing such a problem!!?? Emerging and Re-emerging mmmmm Infectious Diseases W H Y ????? mmmmm mmmmm After great advances in medical research, antimicrobial drug discovery, technology development, improvement in sanitation.. WHY are microbes still posing such a problem!!?? mmmmm mmmmm

Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm قال رسول الله صلى الله عليه وسلم: «لم تظهر الفاحشة في قوم قط حتى يعلنوا بها إلا فشا فيهم الطاعون والأوجاع التي لم تكن مضت في أسلافهم الذين مضوا .» رواه ابن ماجه والحاكم mmmmm mmmmm جاء في الحديث الصحيح الذي رواه ابن ماجة عن عبدالله بن عمر قال: أقبل علينا رسول الله صلى الله عليه وسلم فقال: “يا معشر المهاجرين خمس إذا ابتليتم بهن وأعوذ بالله أن تدركوهن لم تظهر الفاحشة في قوم قط حتى يعلنوا بها إلا فشا فيهم الطاعون والأوجاع التي لم تكن مضت في أسلافهم الذين مضوا، ولم ينقصوا المكيال والميزان إلا أخذوا بالسنين وشدة المؤونة وجور السلطان عليهم، ولم يمنعوا زكاة أموالهم إلا منعوا القطر من السماء ولولا البهائم لم يمطروا، ولم ينقضوا عهد الله وعهد رسوله إلا سلط الله عليهم عدوا من غيرهم فأخذوا بعض ما في أيديهم، وما لم تحكم أئمتهم بكتاب الله ويتخيروا مما أنزل الله إلا جعل الله بأسهم بينهم”

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm 1. Ecological changes & agricultural development 2. Human demographics and behavior 3. Technology and industry 4. Economic development and land use 5. International travel and commerce 6. Microbial adaptation and change 7. Breakdown of public health measures mmmmm mmmmm mmmmm

More Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases More Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 8. Human vulnerability 9. Climate and weather 10. Poverty and social inequality 11. War and famine 12. Lack of political will 13. Intent to harm mmmmm mmmmm

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm 1. Ecology & agriculture mmmmm Placing people in contact with a reservoir of an infection (zoonotic or arthropod-borne) either by: mmmmm mmmmm Increasing proximity Changing conditions Ecological factors usually precipitate emergence by placing people in contact with a natural reservoir or host for an infection hitherto unfamiliar but usually already present (often a zoonotic or arthropod-borne infection), either by increasing proximity or, often, also by changing conditions so as to favor an increased population of the microbe or its natural host. microbe natural host

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm 1. Ecology & agriculture mmmmm Reforestation in USA Increased the number of deer & deer ticks mmmmm mmmmm Increased Human contact with deers Deer tick Deer ticks: natural reservoir of Lyme diseases Lyme disease is a tick-borne bacterial disease caused by Borrelia. The infection and its symptoms can be eliminated by early treatment with antibiotics. Human affection by Lyme disease

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm 1. Ecology & agriculture mmmmm Conversion of grassland to maise cultivation mmmmm mmmmm Rodent Rodents & people come together Rodents are natural reserviour of the virus Argentine Haemorrhagic fever in humans

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm 1. Ecology & agriculture mmmmm C h i n a Pig Farm Duck farm mmmmm mmmmm Mixing vessels Influenza Influenza Influenza

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm 1. Ecology & agriculture mmmmm Increased Rice cultivation in South East Asia. Field mouse mmmmm mmmmm Field mouse is natural reservoir of Hantaan virus Increased human contact with Field mouse Introduction of Korean haemorrhagic fever in Humans

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 2. Human demographics and behavior Inflation of population size Insufficient infrastructures mmmmm mmmmm Use open containers for water Breading mosquitos Dengue fever in Asia

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 2. Human demographics and behavior Urbanization More people concentrated in cities-often without adequate infrastructure Increases in the elderly populations mmmmm mmmmm

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 2. Human demographics and behavior Urbanization Urbanization Increases in children in daycare: working woman with kids under 5 was 30% in 1970, became 75% in 2000. mmmmm mmmmm Fast paced Lifestyles- increase in convenience items and more stress. High-risk behavior- Drug use and unprotected sex

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 3. Technology and industry Modern mass production increases the chance of accidental contamination and amplifies the effect of such contamination. -Contamination of hamburger meat by E.coli strains causing haemolytic uraemic syndrome. -Feeding cattle by byproducts of sheep causing bovine spongiform encephalitis. mmmmm mmmmm

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 3. Technology and industry New diagnostics lead to identification of previously unknown microbes for known diseases e.g. Helicobacter pylori and peptic ulcer. Medical technology - People living longer, but have weaker immune systems. - Blood & organ transplantation transmit infections. mmmmm mmmmm

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 4. Economic development and land use Changing ecology influencing waterborne, vectorborne disease transmission (e.g. dams, deforestation) More exposure to wild animals and vectors (Lyme disease, ehrlichiosis, babesiosis, HPS,…) mmmmm mmmmm HPS:Hantavirus Pulmonary Syndrome

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 5. International travel and commerce Circumnavigation: 365 days, now 36 hours International travelers: 400 millions Increased incidence of both Tuberculosis and Influenza transmission on long flights mmmmm mmmmm Transportation of products - Rapid transport of disease harboring fresh products. - Transport of livestock facilitates transport of viruses and arthropods (esp. ticks)

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 5. International travel and commerce Travel and HIV/AIDS. Cholera and Hajj. Historically: mmmmm mmmmm - Silk route and plague. - Slaves trade and yellow fever. - Migration to new world and smallpox.

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 6. Microbial adaptation and change Lateral transfer is common: shown by genome sequencing. Rapid adaptation: due to high mutation rates in RNA viruses. Rapid build up of rare mutations: because of quick reproduction mmmmm mmmmm Resistance: Antimicrobials used in livestock growth enhancement and over-prescription of antimicrobials by doctors.

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 7. Breakdown of public health measures Decrease in chlorine in water supplies lead to rapid spread of cholera in South America. mmmmm mmmmm Non functioning water plant in Wisconsin, USA lead to outbreak of waterborne cryptosporidium

Major Factors Contributing to the Emergence of Infectious Diseases Emerging and Re-emerging mmmmm Infectious Diseases Major Factors Contributing to the Emergence of Infectious Diseases mmmmm mmmmm 7. Breakdown of public health measures Inadequate vaccinations and Diphtheria in former USSR independent countries. Discontinued mosquito control efforts and dengue and re-emergence of malaria. mmmmm mmmmm

Emerging and Re-emerging mmmmm Infectious Diseases mmmmm Summary mmmmm Infectious diseases will always be there New infectious diseases will always occur mmmmm mmmmm Man and his behavior are the main reasons