Conquest & Resurgence of Infectious Disease-Intro to PH Chpt 9 & 10 Fall 2024 PDF

Chapter 9 The “Conquest” of Infectious Diseases What do you think of when you think of infectious disease? What diseases come to mind?  Infectious Diseases: Major Killers in the Past Bubonic plague Typhus – “Black Death” Yellow Fever...

Chapter 9 The “Conquest” of Infectious Diseases What do you think of when you think of infectious disease? What diseases come to mind?  Infectious Diseases: Major Killers in the Past Bubonic plague Typhus – “Black Death” Yellow Fever Tuberculosis Diphtheria Smallpox Measles Cholera Influenza Typhoid How did we conquer some of these infectious diseases?  Infectious Diseases Were “Conquered” by the 1960s Immunization—When was the first vaccine developed and what was it for? https://www.who.int/news-room/feature-stories/detail/smallpox- vaccines#:~:text=The%20smallpox%20vaccine%2C%20introduced%20by,protected%20against%20inoculated%20variola%20virus. https://www.cdc.gov/poxvirus/monkeypox/vaccines/vaccine-basics.html Antibiotics—When was the 1st antibiotic discovered and what was it? https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/flemingpenicillin.html#:~:text=But%20it%20was%20not%20until,Mary's%20Hospital%20in%20 London. Public health measures – Purification of water (In 1908, Jersey City, New Jersey was the first city in the United States to begin routine disinfection of community drinking water) – Proper disposal of sewage – Pasteurization of milk – Improved nutrition and personal hygiene  Polio Signs & Symptoms of Polio https://www.cdc.gov/polio/what-is-polio/index.htm Polio Vaccine History https://www.history.com/this-day-in-history/polio-vaccine-trials-begin How does polio outbreak happen in NY in 2022 https://www.theguardian.com/us-news/2022/aug/29/polio-us-vaccines-new-york-rockland-county Measles: Most cases in 2019 since 1992  Measles This is the greatest number of cases reported in the U.S. since 1992. More than 73% of the cases were linked to recent outbreaks in New York. Measles is more likely to spread and cause outbreaks in U.S. communities where groups of people are unvaccinated. The majority of cases were among people who were not vaccinated against measles. Measles can cause serious complications. From January 1 – December 31, 2019, 128 of the people who got measles were hospitalized, and 61 reported having complications, including pneumonia and encephalitis. States with Reported Measles 2019 ** (as of December 31, 2019) The states that have reported cases to CDC were Alaska, Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Michigan, Missouri, New Mexico, Nevada, New Hampshire, New Jersey, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Texas, Tennessee, Virginia, and Washington. – What are the vaccination rates for these states? – NEW YORK, NY — New York is among the 10 states with the lowest vaccination rates, according to federal health data. The states that reported outbreaks were California, Georgia, Illinois, Michigan, New Jersey, New York City, New York State, Oregon, Pennsylvania, Texas, and Washington. All measles cases were caused by measles wild-type D8 or B3.  Health Impact of Measles Severe Complications. Some people may suffer from severe complications, such as pneumonia (infection of the lungs) and encephalitis (swelling of the brain). They may need to be hospitalized and could die. As many as one out of every 20 children with measles gets pneumonia, the most common cause of death from measles in young children. Measles | Complications | CDC www.cdc.gov/measles/about/complications.html  Is Measles still a concern? https://www.cdc.gov/measles/data- research/index.html  Smallpox Smallpox - WebMD https://www.webmd.com/a-to-z-guides/smallpox For centuries, smallpox killed millions of people around the world. But thanks to global immunization programs, the deadly infectious disease was wiped out in the late 1970s. Smallpox is a contagious, disfiguring and often deadly disease that has affected humans for thousands of years. Naturally occurring smallpox was eradicated worldwide by 1980 — the result of an unprecedented global immunization campaign. Samples of smallpox virus have been kept for research purposes. This has led to concerns that smallpox could someday be used as a biological warfare agent [See link re: Explosion in Russian lab known for housing deadly small pox virus]. No cure or treatment for smallpox exists. A vaccine can prevent smallpox, but the risk of the vaccine's side effects is too high to justify routine vaccination for people at low risk of exposure to the smallpox virus. Covid Vaccine Update & CDC Covid Tracker per American Medical Association (AMA) & CDC https://www.ama-assn.org/delivering-care/public-health/cdc-covid-19- vaccine-guidelines-when-new-covid-vaccine-coming-out https://covid.cdc.gov/covid-data-tracker/#datatracker-home  Infectious Agents Bacteria – Tuberculosis, cholera, typhoid, tetanus, diphtheria, dysentery, syphilis, streptococci, staphylococci Viruses – Smallpox, poliomyelitis, hepatitis, measles, rabies, AIDS, yellow fever Parasites – Malaria, cryptosporidiosis, giardiasis, roundworms, tapeworms, hookworms, pinworms  Chain of Infection The transmission pattern is composed of links: – Pathogen (infectious agent) – Reservoir – Means of transmission – Susceptible host Public health measures to control the spread of disease are aimed at interrupting the chain of infection at whichever links are most vulnerable.  Means of Transmission Directly from one person to another Aerosol Touching contaminated object and putting hands to mouth, nose, or eyes Contaminated water or food – Fecal-oral route Vectors Sexual contact Carriers  Interrupting Chain of Infection Kill pathogen with antibiotics. Eliminate the reservoir. Prevent transmission: – Hand washing – Quarantine – Condoms Increase resistance of host by immunization.  Public Health Measures Epidemiologic surveillance Epidemiological surveillance is defined as the “ongoing systematic collection, analysis, and interpretation of health data that are essential to the planning, implementation, and evaluation of public health practice” (25). https://www.google.com/search?q=epidemiological+surveillance&rlz=1C1GCEU_enUS896US896&oq=epidmemiological+sur&aqs=chrome.1.69i57j0i13l4j0i13i3 95l5.11035j1j15&sourceid=chrome&ie=UTF-8  Public Health Measures Contact tracing Immunization and treatment of identified patients to prevent further spread Quarantine if necessary CDC’s Morbidity and Mortality Weekly Report (MMWR) https://www.cdc.gov/mmwr/  Examples SARS: Severe acute respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus called SARS-associated coronavirus (SARS-CoV). SARS was first reported in Asia in February 2003. – Controlled by classic public health measures Rabies – Surveillance of wildlife – Immunization of dogs – Post-exposure prophylaxis  Eradication Eradication is possible if there is no nonhuman reservoir and if a vaccine exists. Smallpox was eradicated in 1977. Polio was eradicated from the Western Hemisphere. – Now it is only in a few countries. – There is religious opposition in some countries. Measles is the next target. – Now it is no longer endemic in the U.S.  Fear of Vaccines Rumors spread of vaccines causing autism and SIDS. No MMR Vaccine-Autism Link in Large Study – Study of over 95,000 children included 15,000 unvaccinated 2 to 5 year olds and nearly 2,000 kids already considered at high risk for autism (April 21, 2015) https://www.autismspeaks.org/science-news/no-mmr-autism-link-large-study-vaccinated-vs-unvaccinated-kids https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2831678/ [2010, retracted 12 years after initial report] Side effects do exist for some vaccines. Some parents refuse to accept risks. Herd immunity is lost if many people do not get vaccinated. Pharmaceutical companies are reluctant to develop vaccines. – Low profits – Risk of lawsuits  Whooping Cough https://www.bing.com/videos/search?q=infec tius+disease+video&view=detail&mid=9FCC64 9361207120AA649FCC649361207120AA64&F ORM=VIRE Two vaccines to help prevent whooping cough, DTaP and Tdap (also provide protection against tetanus and diphtheria CDC Recommends Whooping Cough Vaccines for People of All Ages  Chapter 10 The Resurgence of Infectious Diseases  Tuberculosis TB is the leading cause of infectious-disease death worldwide. – One third of the world population is infected. There was a resurgence in the U.S. in the early 1990s. People with HIV are at much higher risk. TB is transmitted by aerosol. Fatality rate is 50% for untreated TB.  Tuberculosis, ctd. Antibiotics are effective but must be taken for several months. Improper use of antibiotics leads to resistance, including multidrug resistance – Then, mortality rate can exceed 50%. Directly observed therapy works. – It is the best approach for preventing antibiotic resistance. In 2007, the CDC revised its requirements for overseas medical screening of applicants for immigration to the U.S. What is Ebola? Symptoms of Ebola Treatment of Ebola Artist’s Intervention in the Ebola crisis 2015 https://www.youtube.com/watch?v=- Wx7g6NbhPs  Ebola https://www.google.com/search?source=hp&ei=if0qXoL4N7K9ggfRi7YI&q=ebola+viru s&oq=ebola&gs_l=psy- ab.1.1.0i131l10.1243.2717..4944...0.0..0.85.345.5......0....1..gws-wiz.......0.bPdx-6sDRik https://www.youtube.com/watch?v=-Wx7g6NbhPs  HIV/AIDS Was first recognized in the U.S. in 1981. Is now a worldwide killer. Is caused by a retrovirus. Attacks the immune system. Screening test recognizes antibodies. We can measure viruses in the blood. Now many drugs are available but no cure.  HIV/AIDS Transmission Sexual contact: – Homosexual Most common in U.S. – Heterosexual Most common around the world Sharing needles: – Intravenous drug use – Medical use of unsterile needles  HIV/AIDS Transmission Mother to infant – Prenatal or during birth – Breastfeeding Blood transfusions – No longer in the U.S. Circumcision helps protect men against contracting HIV from women, but it doesn’t protect women from contracting it from men.  Where Did HIV Originate? Probably originated in Africa. Transmitted cross-species from monkeys or apes. Spread in human populations due to disruption of traditional lifestyles. Spread to Western countries due to changing patterns of sexual behavior and international travel.  HIV/AIDS 30 Years https://www.youtube.com/watch?v=QPEONF3h UBI  Other Emerging Viruses Ebola Monkey pox Hantavirus Other hemorrhagic fevers West Nile virus SARS  Factors That Lead to Emergence of New Infectious Diseases Human activities that cause ecological damage and close contact with wildlife Modern agricultural practices International travel International distribution of food and exotic animals Breakdown of social restraints on sexual behavior and intravenous drug use  Influenza Influenza is an RNA virus like HIV. Virus is constantly mutating. Vaccine must be changed frequently. New lethal strains appear periodically. Epidemic of 1918–1919 killed 20 million to 40 million worldwide. Bird flu and H1N1 are concerns. https://www.cdc.gov/flu/index.htm  New Bacterial Threats Legionnaire’s disease Lyme disease Group A streptococci E. coli O157:H7 in food Antibiotic resistance – From improper medical use – Use in agriculture – MRSA  Public Health Response to Emerging Infections Global surveillance Improved public health capacity Veterinary surveillance Reduction of inappropriate use of antibiotics Institute of Medicine recommendations: – New vaccines – New antimicrobial drugs – Measures against vector-borne diseases  Threat of Bioterrorism Attacks: A bioterrorism attack is the deliberate release of viruses, bacteria, or other germs to cause illness or death. These germs are often found in nature. But they can sometimes be made more harmful by increasing their ability to cause disease, spread, or resist medical treatment.Feb 7, 2019 Approach to bioterrorism is the same as that for natural disease outbreaks. Bioterrorism will probably first be recognized by surveillance. – First signs of an attack are likely to be seen by physicians and hospital emergency room staff. It is best defended against by the same methods as natural outbreaks.  The world's most dangerous bioweapons The Hanta virus from Bunyaviridae family of viruses has a mortality rate of up to 50%.... Anthrax is one of the most potential biological weapons in the world.... Botulinum bacteria as a bio-weapon can be distributed through aerosol or by contamination of water and food supplies. More items...Apr 12, 2015 www.army-technology.com › features › featurethe-worlds-most-danger...  Discussion Question 1 Visit the CDC website on vaccines and immunizations, www.cdc.gov/vaccines. – What evidence can you find about the safety of childhood vaccines?  Discussion Question 2 CDC News & Outbreaks – Visit the website of the Centers for Disease Control and Prevention, www.cdc.gov.  How Emerging & Re-Emerging Infections Differ https://www.youtube.com/watch?v=8swAWix SQPs