Communicable Diseases, Nosocomial Diseases, Emerging and Re-Emerging Diseases

1. Biology 447 - Environmental Microbiology Communicable Diseases, Nosocomial Diseases, Emerging and Re-Emerging Diseases

2. Introduction

3. In 2001, a review of the scientific literature identified 1415 species of infectious organisms known to be pathogenic to humans, including: • 217 viruses and prions, • 538 bacteria and rickettsiae, • 307 fungi, • 66 protozoa and • 287 helminths. Of these, 61% were zoonotic and 12% were associated with diseases considered to be emerging (Taylor, Latham & Woolhouse, 2001).

5. Communicable Diseases: Definition • Defined as • “any condition which is transmitted directly or indirectly to a person from an infected person or animal through the agency of an intermediate animal, host, or vector, or through the inanimate environment”. • Transmission is facilitated by the following: • more frequent human contact due to • Increase in the volume and means of transportation (affordable international air travel), • globalization (increased trade and contact)‏ • Microbial adaptation and change • Breakdown of public health capacity at various levels • Change in human demographics and behavior • Economic development and land use patterns

6. CD- Modes of transmission • Direct • Blood-borne or sexual – HIV, Hepatitis B,C • Inhalation – Tuberculosis, influenza, anthrax • Food-borne – E.coli, Salmonella, • Contaminated water- Cholera, rotavirus, Hepatitis A • Indirect • Vector-borne- malaria, onchocerciasis, trypanosomiasis • Formites • Zoonotic diseases – animal handling and feeding practices (Mad cow disease, Avian Influenza) • Nosocomial Infections- physician or health care worker induced diseases

7. Importance of Communicable Diseases Significant burden of disease especially in low and middle income countries • Social impact • Economic impact • Potential for rapid spread • Human security concerns • Intentional use

8. Communicable Diseases account for a significant global disease burden • In 2005, CDs accounted for about 30% of the global Burden of Disease and 60% of the BoD in Africa. • CDs typically affect LIC and MICs disproportionately. • Account for 40% of the disease burden in low and middle income countries • Most communicable diseases are preventable or treatable.

9. Communicable Disease Burden Varies Widely Among Continents

10. Communicable Disease Burden Varies Widely Among Continents 67%

11. Communicable disease burden in Europe

12. Communicable disease burden in Europe 3%

13. Nosocomial Infections

14. Nosocomial Infection Any infection that is acquired from being in a hospital or other healthcare institution (e.g., nursing home)‏

15. 44,000 - 98,000 preventable deaths occur in U.S. hospitals every year • 17-29 billion healthcare dollars “wasted” because of medical errors

16. Burden of Nosocomial Infection in U.S. Hospitals • 1.7 - 2 million nosocomial infections/year • Results in 80,000-100,000 deaths/year • Medication errors cause ~7,000 deaths • Cost: 5-6 billion dollars/year

17. Emerging Drug Resistance in Bacteria • MRSA = Methicillin-Resistant Staphylococcus aureus • VRE = Vancomycin-resistant enterococcus • 3CRKP = Klebsiella pneumoniae resistant to 3rd generation cepalosporins • FQRPA = Pseudomonas aeruginosa resistant to fluoroquinolones • Clostridium difficile (NAP1) resistant to fluoroquinolones

18. Methicillin-Resistant Staphylococcus aureus (MRSA)‏ • Staphylococcus aureus is commonly carried on the skin or in the nose of healthy people. Approximately 25% to 30% of the population is colonized (when bacteria are present, but not causing an infection) in the nose. • It is one of the most common causes of skin infections but most of are minor (such as pimples and boils) and can be treated without antibiotics. It also can cause serious infections (such as surgical wound infections, bloodstream infections, and pneumonia). Who is susceptible to MRSA infection? • MRSA usually infects hospital patients who are elderly or very ill. You may be at more risk if you have had frequent, long-term, or intensive use of antibiotics. Intravenous drug users and persons with long-term illnesses or who are immuno-suppressed are also at increased risk. • The infection can develop in an open wound such as a bedsore or when there is a tube such as a urinary catheter that enters the body. MRSA rarely infects healthy people.

19. Methicillin-Resistant Staphylococcus aureus (MRSA)‏ • Staphylococcus aureus is commonly carried on the skin or in the nose of healthy people. Approximately 25% to 30% of the population is colonized (when bacteria are present, but not causing an infection) in the nose. • It is one of the most common causes of skin infections but most of are minor (such as pimples and boils) and can be treated without antibiotics. It also can cause serious infections (such as surgical wound infections, bloodstream infections, and pneumonia). Who is susceptible to MRSA infection? • MRSA usually infects hospital patients who are elderly or very ill. You may be at more risk if you have had frequent, long-term, or intensive use of antibiotics. Intravenous drug users and persons with long-term illnesses or who are immuno-suppressed are also at increased risk. • The infection can develop in an open wound such as a bedsore or when there is a tube such as a urinary catheter that enters the body. MRSA rarely infects healthy people.

20. Note: • Staphylococcus aureus and MRSA can also cause illness in persons outside of hospitals and healthcare facilities. • MRSA infections that are acquired by persons who have not been recently (within the past year) hospitalized or had a medical procedure (such as dialysis, surgery, catheters) are know as Community-Acquired-MRSA infections (CA-MRSA • Data from a prospective study in 2003, suggests that 12% of clinical MRSA infections are community-associated, but this varies by geographic region and population. • CDC has investigated clusters of CA-MRSA skin infections among athletes, military recruits, children, Pacific Islanders, Alaskan Natives, Native Americans, men who have sex with men, and prisoners.Factors that have been associated with the spread of MRSA skin infections include: close skin-to-skin contact, openings in the skin such as cuts or abrasions, contaminated items and surfaces, crowded living conditions, and poor hygiene.

21. Note: • Staphylococcus aureus and MRSA can also cause illness in persons outside of hospitals and healthcare facilities. • MRSA infections that are acquired by persons who have not been recently (within the past year) hospitalized or had a medical procedure (such as dialysis, surgery, catheters) are know as Community-Acquired-MRSA infections (CA-MRSA • Data from a prospective study in 2003, suggests that 12% of clinical MRSA infections are community-associated, but this varies by geographic region and population. • CDC has investigated clusters of CA-MRSA skin infections among athletes, military recruits, children, Pacific Islanders, Alaskan Natives, Native Americans, men who have sex with men, and prisoners.Factors that have been associated with the spread of MRSA skin infections include: close skin-to-skin contact, openings in the skin such as cuts or abrasions, contaminated items and surfaces, crowded living conditions, and poor hygiene.

22. Vancomycin-resistant enterococci • Enteroccocci are bacteria that are normally present in the human intestines and in the female genital tract and are often found in the environment. These bacteria can sometimes cause infections. • Vancomycin is an antibiotic that is often used to treat infections caused by enterococci. In some instances, enterococci have become resistant to this drug and thus are called vancomycin-resistant enterococci (VRE). Most VRE infections occur in hospitals. • In the last decade enterococci have become recognized as leading causes of nosocomial bacteremia, surgical wound infection, and urinary tract infection • Enterococci are readily recovered outdoors from vegetation and surface water, probably because of contamination by animal excrement or untreated sewage. In humans, typical concentrations of enterococci in stool are up to 108 CFU per gram

23. Vancomycin-resistant enterococci • Enteroccocci are bacteria that are normally present in the human intestines and in the female genital tract and are often found in the environment. These bacteria can sometimes cause infections. • Vancomycin is an antibiotic that is often used to treat infections caused by enterococci. In some instances, enterococci have become resistant to this drug and thus are called vancomycin-resistant enterococci (VRE). Most VRE infections occur in hospitals. • In the last decade enterococci have become recognized as leading causes of nosocomial bacteremia, surgical wound infection, and urinary tract infection • Enterococci are readily recovered outdoors from vegetation and surface water, probably because of contamination by animal excrement or untreated sewage. In humans, typical concentrations of enterococci in stool are up to 108 CFU per gram

24. Vancomycin-resistant enterococci • Enteroccocci are bacteria that are normally present in the human intestines and in the female genital tract and are often found in the environment. These bacteria can sometimes cause infections. • Vancomycin is an antibiotic that is often used to treat infections caused by enterococci. In some instances, enterococci have become resistant to this drug and thus are called vancomycin-resistant enterococci (VRE). Most VRE infections occur in hospitals. • In the last decade enterococci have become recognized as leading causes of nosocomial bacteremia, surgical wound infection, and urinary tract infection • Enterococci are readily recovered outdoors from vegetation and surface water, probably because of contamination by animal excrement or untreated sewage. In humans, typical concentrations of enterococci in stool are up to 108 CFU per gram

25. Among several phenotypes for vancomycin-resistant enterococci, VanA (resistance to vancomycin and teicoplanin) and VanB (resistance to vancomycin alone) are most common. • In the United States, VanA and VanB account for approximately 60% and 40% of vancomycin-resistant enterococci (VRE) isolates, respectively. • Enterococci are intrinsically resistant to many antibiotics. Unlike acquired resistance and virulence traits, which are usually transposon or plasmid encoded, intrinsic resistance is based in chromosomal genes, which typically are nontransferrable

26. CDC’s National Nosocomial Infection Surveillance (NNIS) System, 1989 - 2004 MRSA = methicillin-resistant Staphylococcus aureus VRE = vancomycin-resistant enterococcus FQRPA = Pseudomonas aeruginosa resistant to fluoroquinolones 3CRKP = Klebsiella pneumoniae resistant to 3rd generation cephalosporins

27. 3CRKP and FQRPA

28. Clostridium difficile (NAP1)‏

29. Potential Bioterrorism Agents

30. Complete List of Potential Bioterrorism Agents from the Center for Disease Control, Atlanta, Georgia, USA From: http://emergency.cdc.gov/agent/agentlist.asp • Anthrax (Bacillus anthracis)‏ • Arenaviruses • Bacillus anthracis (anthrax)‏ • Botulism (Clostridium botulinum toxin)‏ • Brucella species (brucellosis)‏ • Brucellosis (Brucella species)‏ • Burkholderia mallei (glanders)‏ • Burkholderia pseudomallei (melioidosis)‏ • Chlamydia psittaci (psittacosis)‏ • Cholera (Vibrio cholerae)‏ • Clostridium botulinum toxin (botulism)‏ • Clostridium perfringens (Epsilon toxin)‏ • Coxiella burnetii (Q fever)‏ • Ebola virus hemorrhagic fever • E. coli O157:H7 (Escherichia coli)‏ • Emerging infectious diseases such as Nipah virus and hantavirus • Epsilon toxin of Clostridium perfringens

31. Complete List of Potential Bioterrorism Agents from the CDC • Escherichia coli O157:H7 (E. coli)‏ • Food safety threats (e.g., Salmonella species, Escherichia coli O157:H7, Shigella)‏ • Francisella tularensis (tularemia)‏ • Glanders (Burkholderia mallei)‏ • Lassa fever • Marburg virus hemorrhagic fever • Melioidosis (Burkholderia pseudomallei)‏ • Plague (Yersinia pestis)‏ • Psittacosis (Chlamydia psittaci)‏ • Q fever (Coxiella burnetii)‏ • Ricin toxin from Ricinus communis (castor beans)‏ • Rickettsia prowazekii (typhus fever)‏ • Salmonella species (salmonellosis)‏ • Salmonella Typhi (typhoid fever)‏ • Salmonellosis (Salmonella species)‏

32. Complete List of Potential Bioterrorism Agents from the CDC • Shigella (shigellosis)‏ • Shigellosis (Shigella)‏ • Smallpox (variola major)‏ • Staphylococcal enterotoxin B • Tularemia (Francisella tularensis)‏ • Typhoid fever (Salmonella Typhi)‏ • Typhus fever (Rickettsia prowazekii)‏ • Variola major (smallpox)‏ • Vibrio cholerae (cholera)‏ • Viral encephalitis (alphaviruses [e.g., Venezuelan equine encephalitis, eastern equine encephalitis, western equine encephalitis])‏ • Viral hemorrhagic fevers (filoviruses [e.g., Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo])‏ • Water safety threats (e.g., Vibrio cholerae, Cryptosporidium parvum)‏ • Yersinia pestis (plague)‏

33. Complete list of potential bioterrorism agents (CDC)‏ • Anthrax (Bacillus anthracis)‏ • Arenavirues • Bacillus anthracis (anthrax)‏ • Botulism (Clostridium botulinum toxin)‏ • Brucella species (brucellosis)‏ • Brucellosis (Brucella species)‏ • Burkholderia mallei (glanders)‏ • Burkholderia pseudomallei (melioidosis)‏ • Chlamydia psittaci (psittacosis)‏ • Cholera (Vibrio cholerae)‏ • Clostridium botulinum toxin (botulism)‏ • Clostridium perfringens (Epsilon toxin)‏ • Coxiella burnetii (Q fever)‏ • Ebola virus hemorrhagic fever • E. coli O157:H7 (Escherichia coli)‏ • Emerging infectious diseases such as Nipah virus and hantavirus • Epsilon toxin of Clostridium perfringens • Escherichia coli O157:H7 (E. coli)‏ • Food safety threats (e.g., Salmonella species,scherichia coli O157:H7, Shigella)‏ • Francisella tularensis (tularemia)‏ • Glanders (Burkholderia mallei)‏ • Lassa fever • Marburg virus hemorrhagic fever • Melioidosis (Burkholderia pseudomallei)‏ • Plague (Yersinia pestis)‏ • Psittacosis (Chlamydia psittaci)‏ • Q fever (Coxiella burnetii)‏ • Ricin toxin from Ricinus communis (castor beans)‏ • Rickettsia prowazekii (typhus fever)‏ • Salmonella species (salmonellosis)‏ • Salmonella Typhi (typhoid fever)‏ • Salmonellosis (Salmonella species)‏ • Shigella (shigellosis)‏ • Shigellosis (Shigella)‏ • Smallpox (variola major)‏ • Staphylococcal enterotoxin • Tularemia (Francisella tularensis)‏ • Typhoid fever (Salmonella Typhi)‏ • Typhus fever (Rickettsia prowazekii)‏ • Variola major (smallpox)‏ • Vibrio cholerae (cholera)‏ • Viral encephalitis (alphaviruses [e.g., Venezuelan equine encephalitis, eastern equine encephalitis, western equine encephalitis])‏ • Viral hemorrhagic fevers (filoviruses [e.g., Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo])‏ • Water safety threats (e.g., Vibrio cholerae, Cryptosporidium parvum)‏ • Yersinia pestis (plague)‏

34. Neglected Diseases

35. Neglected diseases • Cause over 500,000 deaths and 57 million DALYs annually. • Include the following • Helminthic infections • Hookworm (Ascaris, trichuris), lymphatic filariasis, onchocerciasis, schistosomiasis, dracunculiasis • Protozoan infections • Leishmaniasis, African trypanosomiasis, Chagas disease • Bacterial infections • Leprosy, trachoma, buruli ulcer

36. Mapping Emerging Diseases

37. Emerging diseases on rise Date: 21/02/2008 • An international research team has provided the first scientific evidence that deadly emerging diseases have risen steeply across the world, and has mapped the outbreaks' main sources. • They say new diseases originating from wild animals in poor nations are the greatest threat to humans. • Expansion of humans into shrinking pockets of biodiversity and resulting contacts with wildlife are the reason, they say. Meanwhile, richer nations are nursing other outbreaks, including multidrug-resistant pathogen strains, through overuse of antibiotics, centralised food processing and other technologies. • The study appears in the Feb. 21 2008 issue of the leading scientific journal Nature. Emerging diseases-defined as newly identified pathogens, or old ones moving to new regions--have caused devastating outbreaks already. • The HIV/AIDS pandemic, thought to have started from human contact with chimps, has led to over 65 million infections; recent outbreaks of SARS originating in Chinese bats have cost up to $100 billion. Outbreaks like the exotic African Ebola virus have been small, but deadly.

38. Emerging diseases on rise Date: 21/02/2008 • An international research team has provided the first scientific evidence that deadly emerging diseases have risen steeply across the world, and has mapped the outbreaks' main sources. • They say new diseases originating from wild animals in poor nations are the greatest threat to humans. • Expansion of humans into shrinking pockets of biodiversity and resulting contacts with wildlife are the reason, they say. Meanwhile, richer nations are nursing other outbreaks, including multidrug-resistant pathogen strains, through overuse of antibiotics, centralised food processing and other technologies. • The study appears in the Feb. 21 2008 issue of the leading scientific journal Nature. Emerging diseases (defined as newly identified pathogens, or old ones moving to new regions) have caused devastating outbreaks already. • The HIV/AIDS pandemic, thought to have started from human contact with chimps, has led to over 65 million infections; recent outbreaks of SARS originating in Chinese bats have cost up to $100 billion. Outbreaks like the exotic African Ebola virus have been small, but deadly.

39. Despite three decades of research, previous attempts to explain these seemingly random emergences were unsuccessful. • In the new study, researchers from four institutions analysed 335 emerging diseases from 1940 to 2004, then converted the results into maps correlated with human population density, population changes, latitude, rainfall and wildlife biodiversity. • They showed that disease emergences have roughly quadrupled over the past 50 years. Some 60% of the diseases travelled from animals to humans (such diseases are called zoonoses) and the majority of those came from wild creatures. • With data corrected for lesser surveillance done in poorer countries, "hot spots" jump out in areas spanning sub-Saharan Africa, India and China; smaller spots appear in Europe, and North and South America.

40. Despite three decades of research, previous attempts to explain these seemingly random emergences were unsuccessful. • In the new study, researchers from four institutions analysed 335 emerging diseases from 1940 to 2004, then converted the results into maps correlated with human population density, population changes, latitude, rainfall and wildlife biodiversity. • They showed that disease emergences have roughly quadrupled over the past 50 years. Some 60% of the diseases travelled from animals to humans (such diseases are called zoonoses) and the majority of those came from wild creatures. • With data corrected for lesser surveillance done in poorer countries, "hot spots" jump out in areas spanning sub-Saharan Africa, India and China; smaller spots appear in Europe, and North and South America.

41. Emerging diseases on rise - Date: 21/02/2008 • "We are crowding wildlife into ever-smaller areas, and human population is increasing. The meeting of these two things is a recipe for something crossing over." - Marc Levy, a global-change expert at the Center for International Earth Science Information Network (CIESIN)‏ • The main sources are mammals. • Some pathogens may be picked up by hunting or accidental contact; others, such as Malaysia's Nipah virus, go from wildlife to livestock, then to people. • Humans have evolved no resistance to zoonoses, so the diseases can be extraordinarily lethal. The scientists say that the more wild species in an area, the more pathogen varieties they may harbour. • About 20 percent of known emergences are multidrug-resistant strains of previously known pathogens, including tuberculosis. • Increasing use and reliance on modern antibiotics has helped breed such dangerous strains

42. Emerging diseases on rise - Date: 21/02/2008 • "We are crowding wildlife into ever-smaller areas, and human population is increasing. The meeting of these two things is a recipe for something crossing over." - Marc Levy, a global-change expert at the Center for International Earth Science Information Network (CIESIN)‏ • The main sources are mammals. • Some pathogens may be picked up by hunting or accidental contact; others, such as Malaysia's Nipah virus, go from wildlife to livestock, then to people. • Humans have evolved no resistance to zoonoses, so the diseases can be extraordinarily lethal. The scientists say that the more wild species in an area, the more pathogen varieties they may harbour. • About 20 percent of known emergences are multidrug-resistant strains of previously known pathogens, including tuberculosis. • Increasing use and reliance on modern antibiotics has helped breed such dangerous strains

43. Emerging diseases on rise Date: 21/02/2008 • More diseases emerged in the 1980s than any other decade-likely due to the HIV/AIDS pandemic, which led to other new diseases in immune-compromised victims. • In the 1990s, insect-transmitted diseases saw a peak, possibly in reaction to rapid climate changes that started taking hold then. • "The world's public-health resources are misallocated. Most are focused on richer countries that can afford surveillance, but most of the hotspots are in developing countries. If you look at the high-impact diseases of the future, we're missing the point." • "We need to start finding pathogens before they emerge," said Daszak.

44. Emerging diseases on rise Date: 21/02/2008 • More diseases emerged in the 1980s than any other decade-likely due to the HIV/AIDS pandemic, which led to other new diseases in immune-compromised victims. • In the 1990s, insect-transmitted diseases saw a peak, possibly in reaction to rapid climate changes that started taking hold then. • "The world's public-health resources are misallocated. Most are focused on richer countries that can afford surveillance, but most of the hotspots are in developing countries. If you look at the high-impact diseases of the future, we're missing the point." • "We need to start finding pathogens before they emerge," said Daszak.

45. Nature 451, 990-993 (21 February 2008)‏ Global trends in emerging infectious diseases Kate E. Jones, Nikkita G. Patel, Marc A. Levy, Adam Storeygard, Deborah Balk, John L. Gittleman & Peter Daszak2 Institute of Zoology, Zoological Society of London, Regents Park, London NW1 4RY, UK Consortium for Conservation Medicine, Wildlife Trust, 460 West 34th Street, 17th Floor, New York, New York 10001, USA Center for International Earth Science Information Network, Earth Institute, Columbia University, 61 Route 9W, Palisades, New York 10964, USA Odum School of Ecology, University of Georgia, Athens, Georgia 30602, USA Present addresses: Department of Economics, Brown University, Providence, Rhode Island 02912, USA (A.S.); School of Public Affairs, Baruch College, City University of New York, 1 Bernard Baruch Way, Box D-0901, New York, New York 10010, USA (D.B.).

46. Nature 451, 990-993 (21 February 2008)‏ Summary: • Emerging infectious diseases (EIDs) are a significant burden on global economies and public health. • Their emergence is thought to be driven largely by socio-economic, environmental and ecological factors, but no comparative study has explicitly analysed these linkages to understand global temporal and spatial patterns of EIDs. • Here we analyse a database of 335 EID 'events' (origins of EIDs) between 1940 and 2004, and demonstrate non-random global patterns. EID events have risen significantly over time after controlling for reporting bias, with their peak incidence (in the 1980s) concomitant with the HIV pandemic. EID events are dominated by zoonoses (60.3% of EIDs): the majority of these (71.8%) originate in wildlife (for example, severe acute respiratory virus, Ebola virus), and are increasing significantly over time. • We find that 54.3% of EID events are caused by bacteria or rickettsia, reflecting a large number of drug-resistant microbes in our database. • Our results confirm that EID origins are significantly correlated with socio-economic, environmental and ecological factors, and provide a basis for identifying regions where new EIDs are most likely to originate (emerging disease 'hotspots'). • They also reveal a substantial risk of wildlife zoonotic and vector-borne EIDs originating at lower latitudes where reporting effort is low. We conclude that global resources to counter disease emergence are poorly allocated, with the majority of the scientific and surveillance effort focused on countries from where the next important EID is least likely to originate.

47. Global distribution of relative risk of an EID event A B C D Caption: Global distribution of relative risk of an EID event. Maps are derived for EID events caused by a, zoonotic pathogens from wildlife, b, zoonotic pathogens from nonwildlife, c, drug-resistant pathogens and d, vector-borne pathogens. The relative risk is calculated from regression coefficients and variable values in Table 1 (omitting the variable measuring reporting effort), categorized by standard deviations from the mean and mapped on a linear scale from green (lower values) to red (higher values). Credit: Jones et. al., Nature

48. Geographic Origins of EID events from 1940 to 2004 Caption: Global richness map of the geographic origins of EID events from 1940 to 2004. The map is derived for EID events caused by all pathogen types. Circles represent one degree grid cells, and the area of the circle is proportional to the number of events in the cell. Credit: Jones et. al., Nature Caption: Global richness map of the geographic origins of EID events from 1940 to 2004. The map is derived for EID events caused by all pathogen types. Circles represent one degree grid cells, and the area of the circle is proportional to the number of events in the cell. Credit: Jones et. al., Nature

49. Emerging Diseases in the United States

50. Emerging and re-emerging Diseases in the USA • Chlamydia • Diphtheria * • Encephalitis • West Nile • St. Louis • E. coli • N gonorrhea • H. Influenzae • Hantavirus • Hepatitis A-G (A and B*)‏ • Human herpes viruses • HHV 1-8 • HIV/AIDS • Human papilloma viruses * • Influenza * Emerging strains • Legionella pneumophila • Lyme Disease * Measles * Meningococcus MRSA Pertussis * Poliomyelitis * Rabies Rocky Mountain Spotted Fever Rubella * SARS (Severe Acute Respiratory Syndrome)‏ Salmonellosis Shigellosis S. pneumoniae Syphilis Tetanus * Toxic-Shock Syndrome Tuberculosis * * Vaccination possible