Emerging and Remerging Infectious dieases.pptx

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1. Emerging & Re-emerging Bacterial Infectious Diseases 1 Chijioke A Nsofor PhD, KSM Associate Professor and Group Leader Molecular Epidemiology Research Group Federal University of Technology Owerri

2. Introduction Emerging Bacterial Infectious Diseases: Emerging b acterial infectious diseases are new bacterial diseases recognized in a human host for the first time Re-emerging bacterial Infectious diseases are diseases that have historically occurred in human hosts , but are now: New geographical area New resistance to medical countermeasures (AMR) Reappear after apparent control or elimination 2

3. Animal Amp li f ic at i on C A S E S Emerging Threats Program Human Cases Wild Animal Domestic Animal Early Detection and Control Opportunities Wildlife Surveillance/ Forecasting Fig. 1 One Health – Public health as part of the “ ecosystem ”

4. 4 FIG. 2 Factors that Precipitate the Occurrence and Transmission of Bacterial Infectious Diseases : Spernovasilis et al., 2022

5. Factors Contributing to the Emergence AGENT : Evolution of pathogenic infectious agents (microbial adaptation & change) Development of resistance to drugs: Wrong prescribing practices Non-adherence by patients Counterfeit drugs Use of anti-infective drugs in animals & plants Resistance of vectors to pesticides 5

6. HOST: Human demographic change (inhabiting new areas) Human behavior: 1. Unsafe sexual practices (Gonorrhoea , Syphilis) 2. Changes in agricultural & food production patterns- food- borne infectious agents ( E. coli ) 3. Increased international travel Human susceptibility to infection (Immunosuppression) Poverty & social inequality 6

7. ENVIRONMENT: Climate & changing ecosystems: Deforestation forces animals into closer human contact- increased possibility for agents to breach species barrier between animals & humans Economic development & Land use (urbanization, deforestation) Technology & industry (food processing & handling) International travel & commerce Deterioration in surveillance systems (lack of political will) 7

8. HUMAN ANIMALS ENVIRONMENT VECTORS Zoonosis Population Growth Mega-cities Migration Exploitation Pollution Climate change Vector proliferation Vector resistance Transmission Antibiotics Intensive farming Food production 8 Fig. 3 Factors Contributing to the Emergence of Bacterial Infectious Diseases

9. 9 Examples of Bacterial Emerging Infectious Diseases Bacteria Implications for Africa Targets for prevention Rickettsia felis agent of rickettsia diseases  • 2002: Officially described • Before 2010: Only one case reported in Africa • 2010: Prevalence of about 4% of R. felis in blood samples of febrile individuals without malaria in Senegal and Kenya • 2013: Confirmation of role of R. felis in fever in Senegal • 2015: First detection in blood samples of febrile individuals in Gabon, reaching a prevalence of 39.7 %. Vector-control measures Tropheryma whipplei Agent of Whipple disease • 2001: Officially described • 2010: Prevalence of about 6.4% in blood samples of febrile individuals without malaria in Senegal • 2016: First detection in a febrile patient in Gabon (Fenollar and Mediannikov, 2018) Sanitation facilities

10. 10 Examples of Bacterial Re-emerging Infectious Diseases Yersinia pestis  (plague) •Since 2000: Main outbreaks: Recurrent annual human infections and outbreaks in Madagascar, DRC, Uganda, United Republic of Tanzania (2000) • DRC, Uganda, United Republic of Tanzania (2001) • DRC, Malawi, Mozambique, Uganda, United Republic of Tanzania (2002) • Algeria, DRC, Mozambique, Uganda (2003) • DRC (2005) • DRC (2006) • Madagascar (2017): One of worst outbreak in world in past half century, 202 deaths Reduce risk of wildlife-to-human transmission Vibrio cholera (cholera) • Main outbreaks since 2000: • Madagascar, Somalia (2000) • South Africa (2000–2001) • Chad, Nigeria, Tanzania (2001 ) • Burundi, Côte d’Ivoire, DRC, Liberia, Malawi, Niger (2002) •Mozambique (2002–2004): 17 265 cases, 102 deaths • Benin, Côte d’Ivoire, DRC, Liberia, Mali, South Africa, Uganda, Zambia (2003) • Cameroon, Chad, Zambia (2004) • Niger (2004–2005) • West Africa (2005) • Angola and Republic of South Sudan (2006) • West Africa (2008) • Zimbabwe (2008–2009): largest outbreak, 98 585 cases, 4000 deaths • Zimbabwe (2011 ) • Central Africa, DRC, Sierra Leone, Republic of the Congo (2012) • Republic of South Sudan (2014) • DRC (2015 ) • United Republic of Tanzania (2015–2018): 33 421 cases, 542 deaths • Kenya, Zambia ( 2017), DRC , Mozambique, Somalia (2017–2018 ) • Algeria (2018): Since mid-August 2018, 41 confirmed cases, two deaths, last reported sporadic cases in 1996 in this country (Fenollar and Mediannikov, 2018) Appropriate water and sanitation facilities Oral cholera vaccination (transient protection about 3–5 years) To be alert during conflicts or natural disasters Bacteria Implications for Africa Targets for prevention

11. Vancomycin-resistant enterococci (VRE ) Methicillin/ oxacillin -resistant Staphylococcus aureus (MRSA ) Extended-spectrum beta-lactamases (which are resistant to cephalosporin & monobactams) (ESBLs ) Penicillin-resistant Streptococcus pneumoniae (PRSP ) Diphtheria Multi-drug resistant tuberculosis (MDR-TB ) CRKP- Carbapenem Resistant Klebsiella Pneumoniae Pathogenic  E. coli  strains (O157:H7 & O104:H4) S. typhimurium - DT104 (resistant to five antibiotics: ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline ) 11 Other Bacterial Re-emerging Infectious Diseases

12. Figure 4 : Global examples of emerging and re-emerging infectious diseases Red represents newly emerging diseases; blue, re-emerging/resurging diseases; black, a ‘deliberately emerging’ disease . Fauci, 2021

13. Control of Emerging and Re-emerging Bacterial Diseases Controlling the reservoir Interrupting the transmission Protecting the susceptible host Strengthening of the disease surveillance system Encouraging research initiations for treatment regimens and diagnostics Encouraging research for new methods of control measures 13

14. LAB SURVEILLANCE Serological Surveillance To collect baseline prevalence data To identify high risk areas To identify high risk age group As early warning signal for impending outbreak Microbial surveillance Changing genotype Mutations Development of Antimicrobial Resistance Eg . Salmonella, Cholera, Plague, Anthrax 14 PREVENTIVE STRATEGY

15. International (Collaborating Centres) like CDC, WHO National Reference Laboratories e.g. NCDC Abuja, State laboratories Intermediate (District/Provincial/Medical College) Private Laboratory State Laboratories National Laboratories District Laboratories Private Laboratories Laboratories network in surveillance 15

16. Private laboratories District laboratories Disease Surveillance unit Disease Surveillance unit Disease Surveillance unit National laboratory State laboratories Disease Surveillance unit ACTION 16

17. Laboratory diagnosis of the emerging / re-emerging bacterial infections Importance of laboratory diagnosis The results will alter clinical or infection control management, or as needed for public health surveillance purposes. For infectious diseases, modern serological techniques, more and more based on recombinant antigens, are being proven to be specific, rapid and less labour intensive. PCR may prove very useful and rapid test . 17

18. Recommended laboratory testing in emerging infections Molecular testing- PCR- highly sensitive and specific Rapid test – for flu- need to confirm with PCR Antimicrobial resistance-susceptibility testing , gene detection by PCR 18

19. Emerging Bacterial Infectious Diseases: A Research Approach 19

20. Benefits of Research on Emerging Bacterial Diseases 20

21. Conclusion The true prevalence of many diseases is not known. Since we live in a global village, we cannot afford to be complacent about the tremendous economic, social and public health burden of these diseases. Effective surveillance is the key to their early containment. There is a need to develop epidemiology improved diagnostic facilities, a strong public health structure, effective risk communication, epidemic preparedness and rapid response. 21

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