Unit 1

pathogens spread?

through direct contact, water, air

lyme disease

tick vector

Infections period

time person can spread disease

Chain of infection

transmission occurs when the agent leaves its reservoir or host through a portal of exit, is conveyed by some mode of transmission, and enters through an appropriate portal of entry to infect a susceptible host. infectious diseases result from the interaction of agent, host, and environment

What is an infectious disease

a disease caused by an infectious agent -such as: viruses, bacteria, parasites, fungi -infectious diseases are global problem: historically leading cause of death

Biocrime

use of biological agent to kill or make ill a single individual or small group of individuals, motivated by revenge or the desire for monetary gain by extortion, rather than by political, ideological, religious or other belief

Epidemiological research

variable that may predict/cause an outcome is exposure

Clinical research or mathematical relationships

variable that predicts and causes and outcome is independent variable

incubation period

when someone gets infected to when they start showing symptoms

Experiment

when we manipulate a variable

descriptive epidemiology

who, what, when, where

H5N1 flu

wild birds -> poultry -> humans

How would CJ Peters answer this question? When you hear hoofbeats, think _______.

zebra

secondary attack rate

proportion of people exposed who get disease

case fatality

proportion who die after infection

Miasmatic theory

the belief that people contract disease when they breathe the bad odors of decay and putrefying excrement. (poisonous vapor or mist with particles that cause illnesses) new theory today: germ theory most diseases caused by an infectious agent

Pathogens

disease causing micro-organism (virus, bacteria, protist, fungi)

entering new era

diseases becoming better controlled

Vector- borne diseases

infected animal or human spread through bite of vector -ex: mosquito, ticks, flies, fleas, snails

emerging infectious diseases

new or is (increasing incidence or range)

Systematic approach epidemiologist

-Counts: cases or health events and describes them in terms of time, place, and person -Divides: the #'s of cases by an appropriate denominator to calculate rates -Compares: these rates over time or for different groups of people 1)define case definition 2)epidemiologist finds and collects information about case-patients 3)perform descriptive epidemiology by characterizing cases collectively according to time, place, person 4)calculate disease rate (divide #of cases by size of population) 5)determine if rate is greater than normal expectation and if so identify factors contributing to this increase, compare rate to rate of appropriate comparison group (analytic technique)

Biological weapons and biological warfare(BW)

-Genera protocol (ratified 1925; 65/121 states signed) prohibits the development, production, and use in war of biological and chemical weapons -WHO identified the threat of biological and chemical warfare midst of Vietnam and Cold war =UN resolution 2162B (XXI) 1967, condemming all actions contraty to Genera protocal =1970 WHO report "Health aspects of Chemical and Biological weapons" =WHO guidance "public Health response to biological and chemical weapons" =WHO document focuses on detecting and responding to unusual disease outbreaks -Historically until WWII # soldiers dying from disease increase than combat kills # =WWII: 95% US and 82% Korean war has been related to soldiers being incapacitated because of disease =56% - 75% malaria contributed for US forces in Vietnam war -Catapulting manure, dead plague victims/cattle, blankets with smallpox, shigella & chlorea organisms to poison wells, plague contaminated fleas -Biological warfare programmes prohibited by Biological and Toxin Weapon Convention (170 nations signed)= fairly certain # of rogue nations secretary carrying BW research -preparedness and responding efficiently reduce casualty figure by 75% =bioterrism used to cause significant economic loss by infectious livestock/crops/buildings -ex: foot & mouth disease: lead to loss of nations disease-free status and subsequent bans on export of animals, meat, and derived products, causing significant economic loss

Requirements

-Requirements for bio. attack are obtaining a pathogenic organism or toxin, multiplying it in such a way that the agent retains its viabilty and pathogenic attributes, and developing a method whereby the agent can actually reach and enter a human being sufficient quantities to cause disease (inhaled or swallowed by target population= a enolization or contamination food/water) -vial containing organism, even if pathogenic, does not constitute bio. warfare

important epidemiology tasks

-disease surveillance (notifiable disease registry : by law inform government: tuberculosis, ebola, aids) -diagnostic tests (sensitivity/specificity) -trend analysis (detection bias) -experimental design

Bioterrism bacteria

-may result in biofuel-producing bacteria, lighting from luminescent microbes, or even bio. computers -Likelihood of successful bioterrist attack not very large, given technical difficulties and constraints resulting from the need to work in secret and more probably at the low-technology end of the spectrum than the high-technology end -impact of bioterrist attack can still be high, will affect many lives, and is certainly to be costly in direct and indirect ways

Epidemics

-most epidemics emerge because of external, often climatological or geographical factors -human interference influences the spread of disease -zoonoses -human made outbreaks of disease is the manipulating and distribution of pathogens with the intention of disrupting societies = part of government policy in biological warfare (BW) but also used by terrorist groups/criminals

What is Epidemology

-the study of distribution and determinants of disease or health status in a population -the branch of medicine that deals with the incidence, distribution, and possible control of diseases and other factors relating to health -science of sciences: science of looking at health of populations

successive stages of emergence

1 adaptation to a new host 2 epidemic/pathogenic stage 3 endemic stage 4 fully adapted stage: organism may become nonpathogenic and potentially even beneficial to the new host

Agents selected considered suited for causing mass casualties found to share number of characteristics:

1) High morbidity and potentially high lethal 2) Highly infectious or high toxicity 3) Suited 4 mass production and storage until delivery without loss of pathogenic potential 4) suited for methods aimed at wide-area delivery, and hardy to withstand delivery process 5) stable in environment after dissemination for a period long enough to infect humans 6) suitable having potential as BW agent improved by genetic engineering and weaponization processes

US CDC recognizes 3 categories of bioterrism agent. Category A includes highest priority agents, pose risk to national security because following:

1) easily disseminated or transmitted person to person causing secondary and tertiary cases 2) cause increase mortality with potential of major public health impact, including healthcare facilities 3) cause public panic and social disruption 4) require special action for public health preparedness -Anthrax, Brucellosis, Glanders, Metiodsis, Plague, Q-fever, Salmonellosis, Shigellosis, tularemia (rabbit fever), Smallpox, Venezuelan equine encephalitis, Botulism, Ricin, Staphylococcal, Enterotoxin B : selected because either been weaponized for warfare or have been used in bioterrism, cause most significant impact most suited

Paradigms : 3 philosophies

1) ontology: inquiry into how we define and experience reality 2) epistemology : how we acquire and process knowledge 3) methodology: tools of identifying and categorizing knowledge purpose of research paradigms -define how the world works ; knowledge -define types of questions -published not published -structure the world -provide world's meaning and significance

US department of Health and Human services and US Department of Agriculture declared 3 categories of bio. agents that have potential to pose a severe threat to health and safety. Agents called Biological Select Agents or Toxins:

1)those affect humans 2) those affect animals or crops 3) those affect both

Smallpox

1st disease radicated by humans 1979scientists 1980world health assembly last known case 1975 2yr old rahima baru who: 1967 began an eradication program 15million people developed smallpox annually -2 million people died -1980 smallpox eradicated

Zoonotic

60-80% new human infections from animals (rodents/bats) -others from human-adapted infectious agents (resistance) =Black death pandemic (bubonic plague 25-40 million deaths) =1918 flu pandemic (50 million deaths) =HIV/AIDS pandemic (35 million deaths)

Anthrax case after September 11 attack

=October 2001 through use of postal service, anthrax spores were widely disseminated, including to homes, senate, major newsrooms - resulting in morbidity and mortality and effectively disrupting our way of life and revealing our vulnerability -October 2001, Robert Stevens, Florida - Dr. Bush inspect Gram-stained sample of cerebrospinal fluid : anthrax immediately suspected(Gram-positive bacilli) -medical facilities lab -referral lab (penicillin disc) : Florida department of Health confirmed the identification of bacterium, according to the protocols of Lab. response Network for Bioterrism established by Centers for Disease Control and Prevention (CDC) and Association of Public Health Lab -48 hrs after admittance into hospital Mr. Stevens 19th known case of inhalation anthrax in US since 1900 and 1st since 1976 -Dr. Bush promptly notified local health department officials -largest epidemiologic and criminal investigations in US history : 1st thoughts not related to bioterrism -next 7 weeks 21 additional confirmed/suspected cases found : inhalation cases numbered 11, 5 persons died including Mr. Stevens, 7 confirmed 4 suspected 4 states: Florida, New York, New Jersey, Connecticut, and Washington : confirmed anthrax cases -affected people's lives, economic, social and political consequences resulting from bioterrism and still persist today to affect people =2001 anthrax: perhaps largest epidemiologic investigation of infectious disease outbreak in history of US public health -concluded Bruce Ivins, microbiologist and leading research scientist studying vaccines and cures for exposure to anthrax at the US army Medical Research Institute of Infectious Disease: suicide in 2008 precluded legal resolution of innocence/guilt PROS: 1) ability to identify pathogen in lab 2) deployment of National Pharmaceutical Stockpile for post-exposure prophylaxis 3) decrease in mortality through rapid diagnosis and multidisciplinary care 4) willingness of medical team CONS: 1)anthrax info old, outdated, inaccurate 2) delay in administrating anthrax vaccine due to lack of availability 3) hoarding ciprofloxacin and other antibiotics, to persons far beyond population considered immediately at risk =CDC relied on syndromic surveillance systems to enhance early detection of illnesses caused by biologic agents that could cause a bioterrism attack -program not successful in October 2001 -Astute clinician will again be first to recognize the next patient with illness resulting from deliberate exposure to biologic agent

Case definition

A set of standard criteria for classifying whether a person has a particular disease, syndrome, or other health condition. ; sometimes limitations on time, place, or people -some definitions (national surveillance)=national standards =equivalent/comparable -council of state and territorial epidemiologists (CSTE) CDC = standard case definitions for notifiable infectious diseases -local outbreaks tailored to local situation =clinical criteria include confirmatory lab tests, combinations of symptoms, signs, and other findings =case definitions used during outbreak investigations more likely to specify limits on time, place, and /or people (listeria monocytogenes : from lab) lab confirmation =case definitions not rely on lab cultures results alone, organisms sometimes present without causing disease =case definitions can change over time as more info is obtained (SARS) =case definitions vary according to purposed of classifying occurrence of disease (strict case definition)

FSMA: FDA Food Safety Modernization Act

Background: -48 million people( 1 in 6 Americans) get sick, 128,000 hospitalized, and 3,000 die each yr from foodborne diseases -FDA Food Safety Modernization Act (FSMA) signed into law (Obama) Jan. 4, enables FDA to better protect public health by strengthening food safety system -preventing food safety problems rather than relying primarily on reacting to problems after they occur -FDA important new tools to hold imported foods to same standards as domestic foods -build an integrated national food safety system in partnership with state and local authorities -companies recall food and prepare/issue regulations and guidance documents PREVENTION: -Mandatory preventive controls for food facilities -Mandatory produce safety standards -Authority to prevent intentional contamination INSPECTION AND COMPLIANCE: -Mandated inspection frequency (5 yrs after enactment then no less 3 yrs there after) -Records access -Testing by accredited labs RESPONSE: -Mandatory recall -Expanded administrative detention -Suspected of registration -Enhanced product tracing abilities -Additional recordkeeping for high risk foods IMPORTS: -Importer accountability -3rd party certification -Certification for high risk foods -Voluntary qualified importer program -Authority to deny entry ENHANCED PARTNERSHIPS: -State and local capacity building -Foreign capacity building -Reliance on inspections by other agencies

CORE

Background: -FDA brought together expertise in medicine, punlic health and science to coordinate its efforts to find, stop, and prevent foodborne illness outbreaks -CORE established 2011, CORE teams identified 959 potential outbreaks, responded to 234 outbreaks potentially linked to FDA regulate food products, identified specific food in 100 outbreaks, and warned consumers to avoid those foods 400 publications CORE SIGNALS AND SURVEILLANCE TEAM: -evaluates emerging outbreaks and disease surveillance trends, working with CDC FDA field officers, and state agencies -reviews data including past inspections, sampling results, product distribution, and sourcing info -Considers previous incidents involving similar pathogen and food pairs RESPONSE TEAM: -1 goal: control and stop outbreak -team coordinates investigation, inspections, sampling, and traces product distribution -coordination among FDA, CDC and state/local regulatory, public health and ag. department is crucial to stopping an outbreak -make actions to protect public health or inform public health efforts COMMUNICATIONS TEAM: -monitors emerging and active incident investigations -also prepare responses to inquiries from FDA stakeholders and media regarding outbreaks OUTBREAK EVALUATION AND OUTBREAK ANALYTICS TEAM: -What did we learn? How can we prevent? -look at all aspects o outbreak, from ingredient sourcing to production and distribution -conduct data analyses to recommend ways to integrate preventative measures in food safety activities RECENT OUTBREAK: outbreak investigation of Salmonella Enteritidis: Peaches (August 2020) =(-) for Salmonella sample of peach tree leaves and peaches 4/40 (+) salmonella but different strain from outbreak -Prima wawona/ wawona packing company -October 15 2020 101 cases across 17 states -August 22 2020 Prima Wawona recalled Total illnesses: 101 Hospitalization: 28 Deaths: 0 Last illness: August 27, 2020 States: CA, CT, IA, KS, KY, MD, MI, MN, MO, NJ, NY, OH, PA, VA, VT, WI HOW CORE WORKS: -investigations managed by FDA's CORE Response team: variety of stages limited info or near completion

Who was the supervising veterinarian for Hazelton Research Products?

Dan Dalgard

Modes of Transmission

Direct: infectious agent spread through direct contact or droplet spread -direct contact: skin to skin, kissing, sex and contact with soil or vegetation harboring infectious organism -droplet spread: spray of large, short range aerosols = sneezing, coughing, talking Indirect:transfer from reservoir to host by air particles, inanimate objects (vehicles) or animate intermediators (vectors) -airborne transmission: dust or droplet nuclei suspended in air; less than 5 micorns (last long period of time and go long distance) -vehicles: food, water, biologic products (blood) and formites; can carry or provide environment for pathogen -vectors: mosquitoes, fleasm ticks

What group is Dr. CJ Peters the chief of?

Disease Assessment Division

Neglected Tropical Diseases

Diseases that affect people primarily in the poorest areas of the world in which housing, sanitation, and water supplies are deficient. -affects poorest countries ; neglected

Origin

England : Dr. John Snow used non-medical means to discover source of chlorea outbreak in 1854 (maps and graphs) #'s -suspected contamination of water (southward and Vauxhall co water pump) public health epidemiologist

In what room were the macaque monkeys dying of a bleeding death?

F

At Home

FOOD SAFETY: 1) Clean: always wash food, hands, counters, and cooking tools (Wet, lather, scrub, rinse, dry - hot soapy water) 2) Seperate: keep raw foods to themselves. Germs can spread from one food to another 3) Cook: foods need to get hot and stay hot. heat kills germs -Beef, pork, lamb 145* -Fish 145* -Ground Beef, Pork, Lamb 160* -Turkey, Chicken, Duck 165* 4) Chill: put food in fridge right away -2hr rule -never thaw by taking out of fridge =Think have food illness -save food package and report problem -call USDA, FDA or local health department -Food-poisoning, 1/6 citizens sick each yr -consuming dangerous foodborne bacteria cause illness 1-3 days of eating contaminated food 20min-6 weeks later symptoms: vomiting, diarrhea, abdominal pain, flu like symptoms, fever, headache, body ache -More at risk: pregnant, young children, older adults, weakened immune system

most modern emerging infectious diseas

HIV/AIDS (jumped form chimps to humans)

Implications of Public Health

Knowing entry and exit and transmission help in making control measures. control measures dictated against segment in infection chain most suspectible to intervention Interventions are directed at: -controlling or eliminating agent at source of transmission -protecting portals of entry -increasing hosts defenses =may be directed at controlling or eliminating the agent at its source =may be directed at mode of transmission =strategies protect portals of entry are simple and effective: gloves, bed nets =some increase host defenses: vaccinations =some prevent pathogen from encountering susceptible host (herd immunity)

When did the US army first become aware of hantaviruses, and more specifically Epidemic Hemorrhagic Fever (EHF)?

Korean War

In what state is USAMRIID located?

Maryland

Who was Dr. Peter's Biology teacher?

Mrs. Willie Filleman

PULSENET

OVERVIEW: -national lab network that connects foodborne illness cases to detect outbreaks -uses DNA fingerprinting of bacteria making people sick to detect thousands o local and multistate outbreaks -1996 network began; improved our food safety systems through identifying outbreaks early OUTBREAK DETECTION: -PulseNet: 1st step in identifying a widespread foodborne outbreak -PulseNet labs submit DNA fingerprinting of bacteria from sick patients to CDC when fingerprints are matched, investigations may be launched to detect source of illness -Pulsenet labs use pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS) (most accurate) to detect DNA fingers -Pulsenet also identify bacteria from pet turtles, hedgehogs, animals at petting zoos, rodents, reptiles, animal feed, and recreational water in addition to foodborne illness -Public health microbiologists enters info into electronic database and submit to CDC -CDC's Pulsenet team compares data from across country which helps identify increase in reported illness an trigger investigation -Epidemiologists investigate illness clusters identified by PulseNet links between cases= outbreaks -Whole genome sequencing replace PFGE -PulseNet identifies potential outbreaks through cluster detection -help provide real time surveillance of bacterial foodborne disease and assist epidemiologists in investigation outbreaks; provides communication between public health rates

Who was the senior research scientist at USAMRIID?

Peter Jarling

What government agency did Dr. Peters apply to join to avoid being sent to the Vietnam war?

Public Health service

In what city, was there a potentially airborne filovirus (hemmorrhagic fever) in a monkey lab?

Reston

Where did CJ go to college?

Rice University

What designation did the Navajo Tribal Council give the new hantavirus?

Sin Nombre Virus

In what state did Dr. Peters grow up?

Texas

In what state was CJ Peters born and raised?

Texas

Virologists traditionally name a new virus after what?

The location it was discovered in

Who was recruited and prepared the electron micrographs?

Tom Geisbert

What large city is Reston located near?

Washington, DC

What animal is in the title of the Prologue?

Zebras

Cluster

aggregation of cases grouped in place and time suspected to be greater than # expected, even though expected # may not be known

Counts

allow public health officials to determine the extent and patterns of disease occurrence by time, place, and person. indicate clusters on outbreaks of disease in community -important for health planning

endemic level or baseline

amount of particular disease usually present in a community -not derived level necessarily but rather observed level -expected level of disease

zoonotic disease

animals to humans over 60%

basic reproductive rate

average # of secondary cases

What happens when person gets infected

bacteria/infection gets into body some fight off with immune system others get sick -weak immune system (due to drugs, age, other) or no immunity

Nipah virus

bats -> pigs -> humans

Epidemic Patterns: epidemics classified by how spread through population

common source: group of persons are all exposed to an infectious agent or toxin from same source -point-source outbreak: brief period exposure, everyone who becomes ill does so with on incubation period - steep upslope and more gradual downslope -continuous-common source: exposed over a period of days, weeks, or longer - flattened and widen the peaks of epidemic curve -intermittent-common source: reflecting intermittent nature of exposure propagated outbreak: transmission form 1 person to another -person to person contact; vehicles; vector borne - occur over more than one incubation period Mixed epidemics: common source followed by secondary person-to-person spread others: not common source or propogated (zoonotic)

Endemic

constant presence and/or usual prevalence of disease or infectious agent in population within geographic area

What was the reservoir for the new hantavirus in Chapter 1?

deer mice

Bioterrism

deliberate release of viruses, bacteria or other agents used to cause illness or death in people, but also in animals or plants -aimed at creating casualties, terror, societal disruption, or economic loss, inspired by ideological, religious or political beliefs -success defined by measure of societal disruption and panic, not necessarily # of casualties

newly emerging and reemerging infectious diseases

diseases recognized for 1st time, and diseases that historically have infected humans but continue to appear in new locations or in drug-resistant forms, or that reappear after apparent control or elimination

SARS

emerged from bats -> humans

Pandemic

epidemic that has spread over several countries or continents, affecting a large # of people

risk factors

exposure that increase or decrease the likelihood of developing certain disorders, conditions, or diseases

reemerging

new or more severe disease associated with acquisition of new genes by an existing microbe ex: antibiotic resistance genes, brazilian purponic fever, SARS,MERS B coronavirus

Drug resistance mutations

have also caused reemergence's of certain pathogens such as multi-drug-resistant and extensively drug-resistant tuberculosis, drug resistant malaria, and numerous bacterial diseases

reemerging infectious diseases

have survived and persisted by adapting to changing human populations and to environmental factors that have been altered by humans

What patient symptom led the medical detectives to abandon arenaviruses as the cause and instead look at hantavirus?

high white blood cell counts

transmission reduced?

hygiene measures

herd immunity

immunity in large amount of population protects others

Host

immunity/resistance; malnutrition, alcohol, disease less/low immune response

epidemic

increase often sudden in # of cases of a disease above normal expectation in the population area -occur when the agent and susceptible host are present in adequate #'s and the agent can be effectively conveyed from a source to susceptible host. Results from: =recent increase in amount or virulence of the agent =recent introduction of the agent into a setting where not been before =enhanced mode of transmission so that more susceptible persons are exposed =change in susceptibility of host response to agent =factors increase host exposure or involve introduction through new portals of entry -diabetes and obesity exist in epidemic proportion

Reservoir

infectious agent is the habitat in which the agent normally lives, grows, and multiplies -Human reservoir: sexually transmitted diseases, measles, mumps, streptococcal infection, and many respiratory pathogens. carrier: person inapparent to infection who is capable of transmitting pathogens to others =asymptomatic/passive/healthy carrier: never experience symptoms =convalescent: recovered from illness; transmit to others =incubatory: transmit during incubation period =chronic: continue to harbor pathogen for mnths or yrs -Animal Reservoir: zoonosis; brucellosis (cows and pigs), anthrax (sheep), plague (rodents), trichinellosis/trichinosis (swine), tularemia (rabbits), and rabies -Environmental reservoir: plants, soil, water = Legionella pneumophila

Rabies

isolated to prevent spread to others

fungi

made significant contributions to disease emergence as well

Portal of entry

manner in which a pathogen enters a susceptible host: often same as exit -skin, mucous membrane, blood, oral

observational epidemiology

many times we do not know the cause of disease but we can associate it with certain exposures -leads to us to understand the association between the morbidity and mortality from a disease and certain exposures, habitats, lifestyles choices

Rates

measures relate the #'s of cases during a certain period of time (usually per yr) to the size of the population in which they occurred -# of cases divided by the size of the population per unit of time -comparing disease occurrence during different periods of time -high risk group

Malaria and Yellow fever

mosquito vector

Portal of exit

path pathogens leaves host; corresponds to site where pathogen is localized

hyperendemic

persistent, high levels of disease occurrence

2009 H1N1 pandemic flu

pigs -> humans

Eliminate disease

possible to eradicate certain infectious diseases unlikely that we will eliminate in foreseeable future due to continuous genetic hyper-evolution forces

vaccinations

preventing and reducing pathogens -small amount of inactive or dead pathogens into the body which stimulates body to form antibodies

Sporadic

refers to disease that occurs infrequently and irregularly

prevent chlorea

safe drinking water good sanitation hygiene needs

outbreak

same as epidemic but more limited geographic area