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					Emerging, Re-emerging Infections

Definitions                                                                        Control Measures
         Emerging Infections                         Re-emerging Infections        Surveillance system
Diseases that have increased in              Reappearance of a known infection          Disease & serological surveillance
incidence in past 20 years                   after a decline in incidence               Early warning on imminent outbreak
Diseases that threaten to increase in        Due to failure in public health            Zoonotic infection
future                                       measures (eg. Dengue, Tuberculosis)        National & international collaboration
                                                                                   Vector control
Impact of Emerging & Re-emerging Infections                                             Eradicate vectors
Morbidity & mortality                                                                   Instil public awareness
Public anxiety & fear – limit socializing, travelling                              Enhance understanding on disease patterns & transmission
Economic impact – loss of income                                                        Research on epidemiology & pathogenesis
     Job loss                                                                          Identify risk factors
     Animal culling                                                               Further development & improvement
     Tourism                                                                           Develop rapid & sensitive detection/ identification of pathogens
     Share market                                                                       eg. real-time RT-PCR, microarray
Containment/ controlling cost                                                           Evaluate effectiveness of current approaches & interventions
     Vector control                                                                    Develop vaccine, antibiotics, treatments
     Vaccination                                                                  Enhance understanding of community behaviour
     Research                                                                     (evaluate health promotion activities)
Cost & Damage                                                                      New policies
                                                                                        Screen migrant workers for infectious diseases
Factors contributing to emergence/ re-emergence of diseases                        Access to money (for research activities)
Advent in technology
     Better diagnostic capabilities & surveillance
      (Real time PCR, Microarray)
      Pathogens may already exist but cannot detect previously
      (due to lack of technology)
     Technology can cause new disease
      Contact lenses (new types of eye infection)
Social events
     Economic impoverishment
     War/ civil conflict
     Population growth (dense, easily transmitted diseases)
Changes in human behaviour/ lifestyles
     Opportunity for microorganisms to spread, flourish
     Day care centers, non-existence – common colds, Shigella, EV71
     Sexual behaviour – AIDS, STDs
     Drug – blood-borne diseases
     Outdoor recreation – Leptospirosis, Meliodosis
Ease of travelling & transport
     Influx of tourists & immigrants
      Introduction of new pathogens (eg. SARS)
     Mass distribution & importation of foods (contaminated)
Changes in health care
     New medical devices
     Organ/ tissue transplantation
     Drugs for immunosuppression
     Widespread use of antibiotics
Environmental changes
     New lands/ forests being explored
            o     ↑ Population
            o     Natural resources – mining, paper, furniture
            o     New land explored, contact with unknown reservoirs for
                  disease (eg. Ebola, SARS, AIDS, Marbugs)
     Climate changes – flood, drought (eg. arbovirus)
Microbial evolution (natural evolution of organisms)
     ↑ Virulence (eg. Vibrio cholera 0139 identical to V. cholerae 01)
     Resistance to antimicrobial drugs (eg. Malaria, TB)
      (antigenic shifts, drifts)
      Incomplete antibiotic treatment
Breakdown of public health infrastructure
     Preliminary success to eliminate TB
     Reports, education, funds for social welfare programs & research money
      diverted to other diseases
Lax in vaccination
     Childhood diseases (eg. whooping cough, measles, polio)
     Parents lax in having their children vaccinated
     Unvaccinated children become susceptible
↑ Elderly population
     Weaker immune system
     Susceptible to infection