Newly Emerging and Re-Emerging Diseases: An Overview

1. Newly Emerging and Re-Emerging Diseases: An Overview Benny Cheng Roger Lau Henry Chong

2. Overview • Introduction and Background • Notable Emerging/Re-emerging diseases • Bioterrorism • Transmission Routes

3. Introduction • Infectious diseases remain among the leading causes of death worldwide • This occurs because of three reasons: • 1. Emergence of new infectious diseases • 2. Re-emergence of old infectious diseases • 3. Persistence of stubborn infectious diseases

4. Definition • According to the NIAID: • Emerging Diseases • “Outbreak of previously unknown diseases or known diseases whose incidence in humans has significantly increased in the last two decades” • Re-emerging Diseases • “Known diseases that have reappeared after a significant decline in incidence”

5. How do they emerge? • Changes in human demographics • Exposure to carriers of the disease • Globalization and trade • Genetic variations and mutations • Human behaviour

6. Diseases covered • HIV • Hepatitis • HPV • Herpes • Influenza • Avian Influenza • SARS • Marburg Disease • Malaria • Tuberculosis • Trypanosomiasis

7. HIV & AIDS • Human Immunodeficiency Virus (HIV) – lentivirus • Over time develops into Auto Immunodeficiency Disease (AIDS) • Symptoms – Progressive illness leads to Infections & Cancer • Origin is still a mystery • Closest origin is the Simian Immunodeficiency Virus (SIV) that affects Monkey from Africa

8. Influence Over the Globe • First diagnosed in 1981 in a group of homosexual men • Until 2010, up to 25 million people have died from AIDS • 2.7 million people acquired HIV in 2010; total number of 34 million people

10. Routes of Transmission

11. Prevention and Treatments • HIV / AIDS ARE PREVENTABLE! • Education • Behaviour Modification • Distribution of Condoms • Clean syringes • Sadly, there is miracle vaccine • Scientists are working on it

12. Hepatitis • Hepatitis Virus causes a swelling and inflammation of the liver which leads to serious health conditions • Fatigue, jaundice, weight lose • Hepatitis Forms: A,B,C,D,E,G • Most common in Canada: HAV, HBV, HCV

13. Hepatitis Around the World • 130-170 million people chronically infected with HCV • Estimated 1.4 million cases of HAV annually • 2 billion people infected worldwide • 350 million living with chronic infection • 600,000 people die each year from HBV

14. Transmission of Hepatitis A, B, C

15. Prevention and Treatments • Share common risk factors as other infectious diseases (HIV, tuberculosis) • Wash your hands! • Practice safe sex • Do not share personal items that gets in contact with blood • No cure – only therapeutic drugs

16. Human papillomavirus (HPV) • Virus from the papillomavirus family • One of the most common sexually transmitted infection • Transmitted mainly through sexual activity • 50% of sexually active men/women will have it at some point

17. Symptoms, Treatment and Prevention • Symptoms/signs • Warts  Genital • Cancer  Cervical • Treatment and Prevention • 90% of cases taken care of by Immune system • Vaccination • Safe sex

18. Herpes Simplex Virus • STD caused by viruses HSV-1 or HSV-2 • Transmission from sexual contact • Open sores • Bodily fluid • Skin to skin contact • One in six people will likely be infected • Outbreaks for infected will decrease over the years

19. Herpes Simplex Virus • STD caused by viruses HSV-1 or HSV-2 • Transmission from sexual contact • Open sores • Bodily fluid • Skin to skin contact • One in six people will likely be infected • Outbreaks for infected will decrease over the years

20. Dealing with Herpes • Symptoms • Typically ulcers (sores) and blisters • Can be mistaken for insect bites • Treatment • None, but there is medication to prevent outbreaks • Prevention • Abstinence from sex with infected individuals

21. Stats for HPV and Herpes

22. Influenza • Acute viral infection by influenza virus • Forms A,B,C • A: H1N1 and H3N2 subtypes currently circulating amongst humans • Zoonosis: transfers between animals and humans • Named H and N – Hemagglutinin and Neuraminidase • Strains of flu named after cities in Asia!?

23. Statistics • Seasonal influenza occurs yearly duing autumn and winter • 3-5 million cases of severe illness and 250,000-500,000 deaths • More severe and peaks more often in tropical areas • H1N1 outbreak in Mexico in 2009 • 2000-8000 Canadians die annually

24. Symptoms • Onset of high fever • Dry cough • Headache • Sore throat • Severe illness and deaths amongst people at high risk (children under the age of two and people chronically ill)

25. Transmission, Prevention, Treatment • By contact and airborne by sneezing, coughing • Common in schools and health facilities • How to Prevent it? • Cover your mouth to sneeze • Vaccination

26. Avian Influenza (H5N1) • Avian Flu or Bird Flu • Flu Infection in birds, can mutate to infect humans • Not easily transmitted to humans • 1997: First discovered in Hong Kong in poultry • Wide Scope

28. Impact and Symptoms • Statistics • As of 2011, 562 cases and 329 deaths worldwide • Over 60% of infected die (WHO) • Symptoms • Affects lower respiratory tract in humans • Viral pneumonia • Fever, cough, sore throat, muscle aches, breathing problems

29. Treatment and Future Outlook • Treatment • Oseltamivir • Concerns • History of influenza has shown high mutation rates and pandemics throughout the 20th century • Mutates into new viruses or mixtures into new subtypes

30. SARS • Severe Acute Respiratory Syndrome • Member of Coronavirus • Coughing and sneezing spread infected droplets through surface contact or an aerosol • Able to live on hands and tissues for up to 6 hours

31. SARS • Statistics • First appearance: November 2002, China • According to WHO: 251 cases in Canada, over 5000 in China, 8000+ cases worldwide • Killed 44 in Toronto, 750+ deaths worldwide • Epidemic officially ended in July 2003

32. SARS

33. Symptoms and Treatment • Symptoms • Cough • Difficulty breathing • Chills and shaking • Fever (Over 38 °C) • Headaches • Muscle Pains • Treatment • Antiviral medication, ventilation support

34. Prevention • Quarantine • Screening • Hand Hygiene • Cover mouth/nose when sneezing • Masks can help

35. Marburg Haemorrhagic Fever • Virus from Filoviridae Family • Elongated filaments • First outbreak in 1967 in 2 locations: Marburg, Germany and Belgrade, former Yugslovia • Outbreaks occurred in Angola, Congo, Kenya, and South Africa • Origin: possibly African Fruit Bats or Green Monkeys

36. Symptoms, Prevention & Treatment • Early stage: • High fever, severe watery diarrhea • “Ghost-like visage” • Late stage: • Severe haemorrhagic manifestations all over the body • Any Treatments? • No vaccine • Supplementary therapies and replace lost blood

37. Malaria • Infectious disease from Plasmodium • Typically transmitted by carrier mosquitoes • Most common in underdeveloped countries • Usually near the equator • Estimated between 708 000 and 1 003 000 deaths in 2008 (by WHO)

38. Symptoms, Treatment and Prevention • Symptoms • Fever and elevated temperatures • Sweating and weakness • Kidney failure • Acute respiratory distress syndrome • Treatment and Prevention • Chloroquine, Mefloquine, Doxycycline, Malarone • Mosquito repellent and mosquito nets

39. Tuberculosis • Infections caused by Mycobacterium tuberculosis • Can be present as • Latent TB Infection • TB disease • Antibiotic Resistant strains are emerging • Multi-drug resistant strains immune to • Isonaizid and Rifampicin

40. Symptoms, Treatment, Transmission • Symptoms • Can be asymptomatic (latent) • Chest pains • Coughing up blood • Weakness/fatigue • Treatment • Antibiotics • Transmission • Aerosol

41. Statistics • Nearly one third of the world is infected • TB results in about 2 million deaths yearly • About 9 million people will become infected • TB is one of the main causes of death for HIV infected

42. Tuberculosis

43. Trypanosomiasis • African Trypanosomiasis: Sleeping disease • Occurs through the bite of an infected tsetse fly • A re-emerging disease: most recent epidemic in 2008 in Uganda • Over 500,000 people affected in Africa

44. Types • Trypanosomabruceigambiense • Affects the majority of people Symptoms: Passive until advanced stages • Trypanosomabruceirhodiense • Acute form Symptoms: Rapidly affects neurological system • Also, ChagasDisease: Affects Latin America

46. Diagnosis and Treatment • Diagnosis: • Screening and serological tests • Diagnosis for the presence of the parasite • Staging to determine the state of disease progression, involving lumbar puncture • Treatment • Two stages: • Stage 1: Pentadimine, suramin • Stage 2: Melarsoprol, Eflornithine • Without treatment, it can be fatal

47. Bioterrorism • Viruses and bacteria deliberately released to cause illness or death • Agents are usually spread through air, water or food • Response requires cooperation between public health authorities and law enforcement • Real-time Outbreak Disease Surveillance (RODS) in the USA

48. Categorization • Category A – high-priority agents • Anthrax (2001) • Small pox • Category B – second highest priority • E coli O157:H7 • Clostridium perfringenstoxin • Category C – third highest priority • SARS • H1N1 • HIV/AIDS

49. Other Routes of Transmissions • In the 21st century there are multiple factors: • Economic development and land use • Human demographic and behaviours • International travel and globalization • Balance between human civilizations and microbial speces in nature • Adv of microbes: multiplies and mutates in minutes • Adv of humans: intelligence and will to implement and invent vaccinations