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Emerging and re emerging infections
- 2. INTRODUCTION
- 3. AIM To introduce major concepts related to emerging and re-emerging infectious diseases.
- 4. SCOPE Emerging and Re-emerging infectious diseases Factors contributing to emerge Basic concept of the infectious diseases Challenges to prevent the emergence Recommendation Conclusion
- 5. Infection & Disease o An infection results when a pathogen invades and begins growing within a host. o Disease results only if and when, as a consequence of the invasion and growth of a pathogen, tissue function is impaired.
- 6. “Emerging” & “Re-Emerging” Emerging Infectious diseases whose incidence in humans has increased in the past 2 decades or threatens to increase in the near future have been defined as "emerging.“ Re-emerging Diseases that once were major health problems globally or in a particular country, and then declined dramatically, but are again becoming health problems for a significant proportion of the population. Diseases thought to be adequately controlled making a “comeback” are “re-emerging”
- 7. CONT.. NEW DISEASE EMERGE & OLD DISEASE RE-EMERGE
- 8. DRIVING FORCES TO EMERGE
- 10. Epidemiological TriadofDisease The Epidemiologic Triangle is a model that scientists have developed for studying health problems. It can help your students understand infectious diseases and how they spread.
- 11. Factors Contributing ToEmergence THE AGENT-“What” -The agent is the cause of the disease • Evolution of pathogenic infectiousagents (microbial adaptation & change) • Mutations • Development of resistance todrugs • Resistance of vectors topesticides
- 12. Factors Contributing ToEmergence HOST-“Who” Hosts are organisms, usually humans or animals, which are exposed to and harbour a disease. The host can be the organism that gets sick, as well as any animal carrier (including insects and worms) that may or may not get sick. • Human demographic change (inhabiting newareas)‐ increase contact with animals and natural environment • Human behaviour(sexual& drug use‐sharing needles, drug abuse, body piercing) • Human susceptibility to infection (Immunosuppression)‐ stress and lifestyle changes • Nutritional changes,more useof pesticides Poverty & socialinequality • Wars, civil unrest • food and housing shortages , increased density of living etc.
- 13. Emerging Zoonoses: Human-animal interface Marburg virus HantavirusPulmonary Syndrome Ebolavirus Borrelia burgdorferi:Lyme Deertick Mostomys rodent:Lassa fever Avianinfluenza virus Bats:Nipah virus
- 14. Transmission of Infectious Agent from Animals to Humans‐ ZOONOTICdiseases • >2/3rd emerging infections originate from animals‐ wild & domestic • E.g Emerging Influenza infections in Humans associated with Geese, Chickens &Pigs • Animal displacement in search of food after deforestation/ climate change (Lassafever) • Humans themselves penetrate/ modify unpopulated regions‐ come closer to animal reservoirs/ vectors (Yellow fever,Malaria)
- 16. Emerging Infections in the World 1973 Rotavirus Enteritis/Diarrhea 1976 Cryptosporidium Enteritis/Diarrhea 1977 Ebola virus VHF 1977 Legionella Legionnaire’s dz 1977 Hantaan virus VHF w/ renal flr 1977 Campylobacter Enteritis/Diarrhea 1980 HTLV-1 Lymphoma 1981 Toxin prod. S.aureus Toxic Shock Synd. 1982 E.coli 0157:H7 HUS 1982 HTLV-II Leukemia 1982 Borrelia burgdorferi Lyme disease
- 17. Emerging Infections in the World 1983 HIV AIDS 1983 Helicobacter pylori Peptic ulcer dz 1988 Hepatitis E Hepatitis 1989 Hepatitis C Hepatitis 1990 Guanarito virus VHF 1991 Encephalitozoon Disseminated dz 1992 Vibrio cholerae O139 Cholera 1992 Bartonella henselae Cat scratch dz
- 18. Emerging Infections in the World 1993 Sin Nombre virus Hanta Pulm. Synd. 1994 Sabia virus VHF 1994 Hendra virus Respiratory dz 1995 Hepatitis G Hepatitis 1995 H Herpesvirus-8 Kaposi sarcoma 1996 vCJD prion Variant CJD 1997 Avian influenza (H5N1) Influenza 1999 Nipah virus Encephalitis 1999 West Nile virus Encephalitis 2001 BT Bacillus anthracis Anthrax 2003 Monkeypox Pox 2003 SARS-CoV SARS
- 19. How Ebola Outbreaks Starts ● First human casesstart with infection byan animal ● Batsto chimpanzes,other animals and bush meat. How current outbreak started in unknown, but killing and preparing bushmeat can spreadother viral illnesses ● Infection from person-to-person creates anoutbreak • Direct or indirect physical contact with body fluids of asick infected person (blood, saliva, vomitus, urine, stool,semen) ● Well known locations where transmissionoccurs • Hospital: • Health care workers, other patients, unsafeinjections • Housesand Communities: • Family, friends, contacts caring for ill, throughfuneral practices---ie contact with deadbodies
- 20. Critical Issues ● First large Ebolaoutbreak in WestAfrica ● Underlying weaknessin healthsystems ● Lackof preparednessand poor surveillance, health care, diagnostics, communications … • Healthworkerinfections & inadequateinfection control & prevention Theaffected countries inWestAfrica havesomeof the worst physician–patient ratiosin the world: – Liberia: more than 86000patients perphysician – SierraLeone:more than 45000patients perphysician Effect of fear ● Strongcommunity resistance in places……..
- 21. Emerging Virus 2001 - Nipah Virus(Bangladesh, India) 2003 - SARS Coronavirus 2004 - Avian Influenza(H5N1), Thailand, Vietnam 2006 - Influenza H5N1(Egypt, Iraq) - New Human Rhinovirus(USA) 2007 - Nipah Virus(Bangladesh) - LCM like Virus(Australia) - Polyoma like virus(Australia) 2009 - Influenza H1N1 2011 - Crimean Congo Hemorrhagic Fever (India) Re-emerging Virus • Ebola • Marburg • Dengue • Yellow fever • Chikungunya • Chandipura • West Nile Virus • Rift Valley Fever • Human Monkey Pox
- 22. Emerging Bacteria • Drug resistant MTB- Both MDR and XDR • MRSA • VRE • CR – GNB esp. Klebsiella • E. coli O104: H4 • Stenotrophomonas spp. • Extended spectrum beta- lactamase producing pathogens: Re-emerging Bacteria • Cholera, H. pylori, • Neonatal tetanus • Yersinia pestis • Rickettsia • Cl. Difficile • Cl. Botulinum • Bacillus anthracis (due to bioterrorim) • Fransciella
- 23. Emerging Parasites • Crptosporidium • Drug resistant Malaria • Cyclospora • Acanthamoeba Keratitis • Gnathostoma Re-emerging parasites • Amoebiasis • Schistosomiasis • Cysticercosis/taeniasis • Hydatid disease
- 24. Emerging Fungi • Non albicans Candida • Penicillium marneffi • Apophysomyces spp. • Fusarium • Trichosporon • Curvularia,Alternaria Re-emerging fungi • Zygomycosis • Aspergillosis • Penicilliosis • Histoplasmosis
- 25. Infectious causes of chronic disease Disease Cervical cancer Chronic hepatitis, liver cancer Lyme disease (arthritis) Whipple’s disease Bladder cancer Stomach cancer Peptic ulcer disease Atherosclerosis (CHD) Diabetes mellitus, type 1 Multiple sclerosis Inflammatory bowel disease Cause Human papilloma virus Hepatitis B and C viruses Borrelia burgdorferi Tropheryma whippelii Schistosoma haematobium Helicobacter pylori Helicobacter pylori Chlamydiae pneumoniae Enteroviruses (esp. Coxsackie) Epstein-Barr v, herpes vv? Mycobacterium avium sub-spp. Paratuberculosis, Yersinia
- 26. Prevention of Emerging Infectious Diseases Surveillance and Response Applied Research Infrastructure and Training Prevention and Control
- 27. How to tackle theseinfections Public health surveillance & responsesystems • Rapidly detect unusual, unexpected,unexplained disease patterns • Track& exchange information in realtime • Response effort that can quickly becomeglobal • Contain transmission swiftly &decisively
- 28. GOARN Global Outbreak Alert & ResponseNetwork • Coordinated by WHO • Mechanism for combating international disease outbreaks • Ensure rapid deployment of technical assistance, contribute to long‐term epidemic preparedness& capacity building
- 29. • Surveillance at national, regional, globallevel –epidemiological, –laboratory –ecological –Anthropological • Investigation and early controlmeasures • Implement prevention measures –behavioural, political, environmental • Monitoring, evaluation
- 30. International Health Regulations 2005 Four major changes in therevision • Public Health Emergency ofInternational concern • Epidemic alert and response • National Focal Point • Dictates the core requirementsfor: – surveillance and response – ports of entry
- 31. Response Verification Assessment Investigation National Surveillance System National Laboratory System Detection (Early Warning) Veterinarian Surveillance System Food Surveillance Notification/ Risk Communication National Health Emergency Response System Health Care Services Public Health Measures Health Care Services The Role of the National Epidemic Alert and Response System Media, General Public Authorities/ Decision Makers WHO International Unofficial (Rumors) Sources
- 32. National Surveillance: Current Situation • Independent vertical controlprogrammes • Surveillance gaps for importantdiseases • Limited capacity in field epidemiology, lab. diagnostic testing, rapid fieldinvestigations • Inappropriate casedefinitions
- 33. Ecological disruption and human intrusion into new ecological system increases the exposure of human to new infectious agents. Usually tropical & Developing countries are HOT SPOT of outbreak of diseases
- 34. Climate change is another potential driver that shifts the ecological niche or range of the diseases. Long-term impact of global warming, some major climatic events caused disease outbreaks in the areas that have not experienced the disease before.
- 35. Urbanization and Industrialization impact the prevalence and scope of both infectious and chronic diseases. High risked sexual practices, multiple sexual partners and use of substances directly transmit the diseases Overcrowding causes person to person rapid spreading of diseases. Poor housing quality, poor sanitation and water supply infrastructure.
- 36. International trade of goods and services through international border facilitate the spread of diseases by bringing pathogen to new geographical areas. Travelers are exposed to variety of pathogen, many of them have never encountered and no immunity to many diseases.
- 37. EVOLUTION OF THE INFECTIOUS AGENT Mutations in bacterial genes that confer resistance to antibiotics – 20% Multidrug-resistant & extremely drug- resistant TB Multi drug resistant P.falciparum
- 38. REDUCED HUMAN IMMUNITY Immunization failure (breakdowns in public health measures) Increased number of immunocompromise d hosts.
- 39. War & Political conflict cuase breakdown of public health infrastructure has role in emergence of diseases. Poor primary health care services may not be equipped to deal with some infectious outbreaks
- 40. Disease Pandemic Influenza Infectious agent Influenza virus Year recognized New viral strain emerge periodically 1967 Marburg virus Before 1976 1976 Salmonella entertidis Ebola virus 1983 Murburg hemorrhagic fever Salmonellosis Ebola hemorrhagic fever AIDS 1983 1989 1998 2002 Gastric ulcers Hepatitis C Nipah encephalitis VRSA infection 2003 2015 SARS (severe acute respiratory syndrome) Zika Human Immuno-deficiency Virus Helicobacter pylori Hepatitis C virus (HCV) Nipah encephalitis Vancomycin resistant S. aureus SARS-associated coronavirus Zika virus EMERGING DISEASES
- 41. RE-EMERGING DISEASES DISEASE DENGUE FEVER MALARIA MENINGITIS SCHISTOSOMIASIS RABIES CHOLERA POLIO YELLOW FEVER TUBERCULOSIS AGENT Dengue virus Plasmodium species (protozoan) Group AStreptococcus (bacterium) Schistosoma species (helminth) Rabies virus Vibrio cholerae 0139 (bacterium) Poliovirus Yellow fever virus Mycobacterium tuberculosis
- 44. SARS: The First Emerging Infectious Disease Of The 21st Century (China, 2003) SARS (Severe Acute Respiratory Syndrome) Total 8429 cases; 824 deaths 30 countries in 7-8 months in 2003
- 45. The 2014 Ebola outbreak is the largest in history. Primarily affecting Guinea, Northern Liberia, and Sierra Leone. Ebola virus disease (EVD), previous known as Ebola hemorrhagic fever (Ebola HF) Fatality rate of up to 90% Transmitted by direct contact with the blood, body fluids and tissues of infected animals or people
- 46. More than 11,000 deaths only in Afric
- 49. Tuberculosis or TB is an infectious bacterial disease caused by Mycobacterium tuberculosis, which most commonly affects the lungs. In the 18th and 19th centuries, a tuberculosis epidemic rampaged throughout Europe and North America. In 1993 the World Health Organization (WHO) declared that TB was a Global Emergency; the first time that a disease had been labeled as such. TUBERCULOSIS
- 50. Approximately 390 million people worldwide infected with the dengue virus each year.
- 51. Since December 2014, swine flu has claimed the lives of over 1,300 people in India, making it the worst outbreak of the virus in the country since SWINE FLU (H1N1 Virus)
- 52. Highly Pathogenic Avian Influenza (H5N1)
- 53. Epidermodysplasia Verruciformis (Tree Man) GENETICS The cause of this condition is an inactivating PH mutation in the EVER1 or EVER2 genes which are located adjacent to one another on Chromosome 17
- 54. MALARIA Infectious agent is Plasmodium species Malaria is transmitted among humans by female mosquitoes of the genus Anopheles.
- 55. LEPTOSPIROSIS
- 56. CHOLERA Causative agent is Vibrio cholera Water borne disea
- 57. Reforestation in USA Increased the number of deer & deer ticks Deer ticks are natural reserviour of Lyme diseases Increased Human contact with deers Human affection by Lyme disease
- 58. Conversion of grassland to maise cultivation Rodents come to people People go to rodents Rodents are natural reserviour of the virus Argentine Haemorrhagic fever in humans
- 59. Pig Farm Duck farm C h i n a Mixing vessels Influenza Influenza Influenza Influenza Influenza
- 60. Increased Rice cultivation in South East Asia Increased human contact with Field mouse Field mouse is natural reservoiur of Hantaan virus Introduction of Korean haemorrhagic fever in Humans
- 61. FactorsContributingToEmergence ENVIRONMENT-“Where” The environment is the favourable surroundings and conditions external to the host that cause or allow the disease to be transmitted. • Climate& changingecosystems • Economic development & Landuse (urbanization, deforestation) • Technology & industry (food processing& handling) • Changes in agricultural & food production patterns food‐borne • infectious agents (E.coli)
- 63. MURBURG VIRUS (Murburg Hemorrhagic Fever) Varying pathogenicity (mortality ranging from 21-80%). Responsible for 1967 outbreak in Europe. Outbreaks in 2000 in Democratic Republic of the Congo and 2005 in Angola. Currently no vaccine or treatment.
- 64. PNEUMONIC PLAGUE SEPTICEMIC PLAGUE BUBONIC PLAGUE Tlea (Ceratophyllus faciatus)
- 65. EID IN SEA REGION EID – a leading cause of death globally 17 m die annually from ID – SEA accounts for 41% or 7 m deaths EID cause suffering & impose financial burden on society Plague outbreak in 1994 cost India over 1.5 B USD due to loss in trade, employment & tourism In Thailand cost of one AIDS patient more than 5000 USD Overall costs for India on account of AIDS estimataed at 11 b USD Increasing or persistent poverty & poor living conditions continue to expose millions of people to the hazards of infectious diseases. The low priority & support given to public health services is most important factor.
- 66. MANAGEMENT OF EID A proactive and planned approach to ensure the appropriate prevention and control of the spread of disease. Strategic planning should include: Phase I (non-alert) is a routine, preparatory state; Phase II (alert) is the detection, confirmation and declaration of changes identified during non-alert conditions; Phase III (response) includes the ongoing assessment of information and the planning and implementation of an appropriate response, which includes the coordination and mobilization of resources to support intervention activities Phase IV (follow-up) activities include re-evaluation,
- 67. RECOMMENDATION Strengthening epidemiological surveillance & laboratory capabilities and services . Establishment of a rapid response team. Monitoring antimicrobial resistance. Establishment of international disease surveillance. networking and advocacy. Screening on International travels and trades. Networks of laboratories that link countries and regions need to be established. Strong national and regional public health systems.
- 68. Prevention Partners Hospitals Local Health Departments Business & Industry Political Leaders Healthcare Providers Professional Organizations CDC Consumers Ministry of Health International Health Organizations Government Agencies Public Health, Medical, & Veterinary Schools
- 69. Emerging Infections Network • In 1995, the CDC granted a CooperativeAgreement Program award to the Infectious Diseases Society of America (IDSA) to develop a provider‐ based emerging infections sentinel network: the Emerging Infections Network (IDSA EIN).
- 70. Emerging Infections NetworkWorks • IDSA EIN has evolved into a flexible sentinel network of over 1,100 disease composed infectious specialists primarily from North America, with some global members. The overarching goal of the EIN is to assist CDC and other authoritiespublic health with surveillance for emerging diseases and infectious related phenomena.
- 71. • Detect new or unusual clinicalevents; • Identify cases during outbreakinvestigations; • Gather information about clinical aspectsof emerging infectious diseases; • Help connect members to the CDC and other public health investigators;and • Develop new methods for gathering epidemiological and clinicalinformation. TheSpecific goals of the EIN areto:
- 72. STRATEGIES TOREDUCE THREATS • IMPROVE GLOBALRESPONSECAPACITY – WHO – National Disease Control Units (e.g.USCDC, CCDC) • IMPROVE GLOBALSURVEILLANCE – Improve diagnostic capacity (training,regulations) – Improve communication systems (web, e‐mailetc.) – Rapid dataanalysis – Develop innovative surveillance and analysisstrategies – Utilize geographical informationsystems – Utilize global positioningsystems – Utilize the Global Atlas of Infectious Diseases(WHO)
- 73. STRATEGIES TOREDUCE THREATS • USE OFVACCINES – Increase coverage and acceptability (e.g.,oral) – New strategies fordelivery (e.g.,nasal spray administration) – Develop new vaccines – Decrease cost – Decrease dependency on “coldchain” • NEW DRUG DEVELOPMENT
- 74. STRATEGIES TOREDUCE THREATS • DECREASE INAPPROPRIATE DRUGUSE – Improve education of clinicians andpublic – Decrease antimicrobialuse in agriculture and food production • IMPROVE VECTORANDZOONOTIC CONTROL – Develop new safeinsecticides – Develop more non‐chemical strategies e.g.organicstrategies • BETTERAND MOREWIDESPREAD HEALTH EDUCATION (e.g.,west Nile virus; bed nets, mosquitorepellent)
- 75. ROLE OFTHEPUBLIC HEALTH PROFESSIONAL • Establish surveillancefor: – Unusual diseases – Drug resistantagents • Assure laboratory capacity to investigate new agents (e.g., high‐throughput labs) • Develop plans forhandling outbreaks of unknown agents • Inform physicians about responsible antimicrobialuse
- 76. ROLE OFTHEPUBLIC HEALTH PROFESSIONAL • Educate publicabout – Responsible drug compliance – Emergence of newagents – Infection sources • Vector control • Malaria prophylaxis • Be aware of potential adverse effects of intervention strategies • Anticipate future healthproblems • Promote health and maximize humanfunctional ability
- 77. Need for global help to Developingcountries Commitment to technology transfer and global collaboration is essential if we are to have the agility requiredto keep pace with infectious diseases. surveillance emerging Pathogen discovery can promote and global interaction via collaborations on matters that know no national or political boundaries but simply reflect our commongoals.
- 78. CDC Emerging Infections Priority Issues • Antimicrobial resistance • Food and watersafety • Vectors and animalhealth • Blood safety • Infections that cause chronicdiseases • Opportunistic infections • Maternal and childhealth • Health of travelers andrefugees • Vaccines
- 79. Summary Humans, domestic animals and wildlife are inextricably linked by epidemiology ofinfectious diseases (IDs). IDs will continue to emerge,re‐emergeand spread. Human‐induced environmental changes, inter‐ species contacts, altered social conditions, demography and medical technology affectmicrobes’ opportunities.
- 81. Thank You!!!