Epidemiology Quiz 3
Atypical pneumonia's (Community-Acquired Pneumonia)
- more mild typically - mycoplamsa and chlamydophila = transmitted via aerosol droplets among ppl in close living quarters = family, students, the military - "walking pneumonia" = lack of acute illness in most patients
Streptococcus pneumoniae (Community-Acquired Pneumonia) - shape, factors/risks, vaccines
- pneumococcus - small, gram + flattened coccus (often appearing in pairs) - factors: old age (or v young), season, underlying viral respiratory disease, diabetes, chronic abuse of alcohol/narcotics - vaccine ENCOURAGED *# at end of vaccine name is amount of serotypes included in vaccine* 1) pneumococcal polysaccharide vaccine PPSV23 (Pneumovax) 2) pneumococcal conjugate vaccine PCV13 (Prevnar)
Measles - Treatment
- really just treating the symptoms - reducing fever - suppressing cough (ex: NyQuil) - Replacing lost fluid (ex: drinking water) - remedies to relieve neurological + respiratory symptoms and to sustain nutrient, electrolyte, and fluid levels - Vitamin A supplements are recommended (because it is a vitamin that helps boost immune response)
Measles (facts)
- viral - also rubella - typically a childhood disease - HIGHLY infectious (RO = 16) - humans are the ONLY host (reservoir)
Measles - Pathogenesis and Virulence factors (how it enters/where it implants itself, travels where?, fusing?)
- virus implants on respiratory mucosa (enters via resp. Tract) —> infects the tracheal/bronchial cells - travels to lymphatic system (multiples + enters the bloodstream (VIREMIA!) which carriers the virus to skin and organs - cell membranes of adjacent host cells fuse into large syncytial (giant cells w/many nuclei) and no longer perform their proper function
Is the infectious dose known at this point in time for legionella pneumophila?
Nope, Dr. K said he was unable to discover the infectious dose number.
Pharyngitis: streptococcus pyogenes — prevention and treatment (methods)
Prevention: - no vaccine exists - good hand washing, esp. after coughing, sneezing, and before preparing foods + eating Treatment: - penicillin = antibiotic of choice - cephalexin = used for patients w/penicillin allergy - most sore throats are caused by s. Pyogenes can resolve on their own, but antibiotic treatment is needed to prevent serious sequelae
Measles (vaccine, how many killed before vaccine, deaths dropped since 2002, and parents relation with measles vaccine)
- extremely effective vaccine - has been available since 1963 (about 367 children die each day despite vaccine) - 6 million people died every year (before vaccine introduced) - dropped 74% since 2002 - parents in dev. Countries opting out of the vaccine due to speculation between vaccination and autism (anti-vaccine project)
Measles - post infection complications (5 main examples)
- laryngitis - bronchopneumonia - secondary bacterial infections (such as ear and sinus infections) - pneumonia - encephalitis (resulting in neurological system damages/permanent brain damage/epilepsy)
About _____% of people who get sick from Legionnaire's disease will die
10%
As of 9/26/2020 there were how many cases of legionella pneumophila reported in the US? OH? What about in 2019?
2,962 cases in US/ 268 in OH; 6,697 in US/ 566 in OH
Incubation period and onset of COVID-19
2-10 days; 5-6 days
We have identified over ___ species that cause legionella and around ___ serotypes
50, 70
Where in the lungs does the legionella pneumophila target?
Alveolar macrophages and neutrophils
Legionella replicates within?
Amoeba
Viremia - what is it?
An infection that is spread via the bloodstream
What is the estimation of cases/yr for legionellosis?
Around 50,000-100,000 (this number is a higher estimation than what is actually reported because of the cases that may not be reported)
Legionnaire's disease and pontiac fever are caused by what pathogens?
BOTH Legionella pneumonphila!
Why is it that the area within the lungs where legionella pneumophila targets ironic?
Because the place where legionella pneumophila targets is the place within the lung that is supposed to help REDUCE infections in the respiratory tract...but this is the place where legionella pneumophila thrives !!
Why is having an at-home hot tub dangerous and a risk factor for breeding legionella pneumophila ?
Because the temp is usually higher (danger zone of 37 degrees C/100 degrees F) and can foster pathogens (especially if the individual doesn't shower before getting into the water. PREVENTION: treat water w/halogens (Br + Cl) to properly clean to limit risk of legionella pneumophila
What type of coronavirus does COVID-19 belong to? What family?
Beta coronavirus; coronaviridae
How is COVID-19 specifically named?
COronaVIrus DIsease 2019 (19 included from 2019)
COVID-19 information for USA (cases, deaths, and cases within the last week of oct. 12)
Cases: 7,740,934 Deaths: 214,108 Last week of Oct. 12: 344,300
SARS-CoV can be transmitted from animal to human (________ _________) and human-to-human (______)
Direct contact; droplet/aerosols
T/F: legionella does not occur naturally in freshwater environments
FALSE! Legionella does occur naturally in freshwater environments, like lakes and streams.
T/F: Pontiac's disease can be treated with antibiotics
FALSE! The fever is actually treated with supportive care (because the illness is self-limiting)
T/F: antibody treatment/antiviral meds are typically treatments for the common cold
FALSE! Treatment for the common cold is simply for symptoms only
T/F: Studies suggest that the virus is unable to be aerosolized + travel farther, remaining in the air for up to 30 minutes
FALSE; the virus is ABLE to do the above/ is viable for up to 3 hours
When is someone infectious w/COVID?
Few days before signs/symptoms and also a week after infection
What type of coronavirus affects aviation species?
Gamma coronavirus
What is the key to keeping legionella out of water systems in buildings?
Good Building Management !!
Legionella pneumophila is what type of organism?
Gram-negative bacterium
Various types of streptococcus and the bacteria caused by it
Group A strep - s. Pyogenes = responsible for strep throat Group B strep - s. Agalactiae - puerperal sepsis, childbed fever Non-Beta-Hemolytic Viridans Streptococci - s. Mutant = causes cavities S. Pneumoniae - causes respiratory tract pneumonia
A North Carolina State Fair _____ ___ was the reason for ____ people testing positive for legionnaire's disease.
Hot tub; 100
Transmission of the common cold
Indirect contact, droplet contact (aerosols, H2O droplets)
What is pharyngitis? (What does it do and what is it caused by?)
Inflammation of the throat; can be viral or bacterial-induced
Legionella pneumophila is a/an ________ pathogen
Intracellular; this means that the microbe is able to live within our macrophages
Legionella pneumophila has a (LOT/LITTLE) of peptidoglycan
LITTLE; this is because of the gram-negative nature of the microbe (thin cell wall)
Immunocompromised individuals usually come down with what sub-type illness of legionellosis?
Legionnaire's disease !
Macula-splat rash diseases
Maculopapular: - skin eruptions caused by a variety of microbes - flat to slightly raised colored bumps Measles (Rubeola) *is a maculopapular rash* - rubella - fifth disease - roseola
Measles - Transmission and epidemiology (transmitted via, reservoir of measles, person infectious during what stages?)
One of the MOST contagious infectious diseases ! - tranmissted via respiratory droplets - humans = only reservoir - person infectious during: periods of incubation, prodrome phase, and skin rash but NOT during convalescence (the gradual recovery of disease)
MERS-CoV originated from...?
Originated from a caramel reservoir —> direct transfer to humans
Where did SARS-CoV and SARS-CoV-2 likely originate from? What is the track to humans?
Originated likely from BATS (as the reservoir) —> small mammals intermediate hosts —> humans
How many common cold causative agents are there?
Over 200 different viruses (known to cause the common cold)
Signs and symptoms of Pharyngitis
Pain Inflammation of the throat Reddened and/or swollen mucosa
Community-acquired legionella pnumophila
Pneumonia that is acquired from the community (of the patient)
Nosocomial pneumonia
Pneumonia that is acquired from the hospital
Pharyngitis: streptococcus pyogenes — culture and diagnosis
Rapid diagnosis tests of pharyngeal swab specimens - use antibodies to detect group A streptococci - BUT LOTS of false negatives THUS culturing phenotypically is best method !! Culturing of pharyngeal swab specimens - plated on sheep blood agar - s. Pyogenes causes beta-hemolysis (look at the picture)
Serotyping in the case of serotypes of legionella means?
Recognizing different organisms using immunotypic (antibody) response/methods of patient(s)
What type of pathogen is legionella pneumophila? What does it cause?
Respiratory pathogen, causes respiratory tract infections
What is measles also known as?
Rubeola
How did scientists name legionella (bacterium)?
Scientists named bacterium after an outbreak in Philadelphia in 1976 Many people who went to an American Legion Convention got sick w/pneumonia (lung infection)
Symptoms of the common cold
Sneezing, scratchy throat, runny nose, fever in children "Relatively mild" - Dr. K
What is the genome of COVID-19
SsRNA (single-stranded RNA)
How many beta-coronaviruses have crossed the species barrier since 2000; what are they + where/when did the coronaviruses emerge?
THREE beta-coronaviruses !! 1) SARS-CoV: Guangdong province of China/2002 2) MERS-CoV (Middle-East Respiratory syndrome coronavirus): Arabian peninsula/2012 3) SARS-CoV-2 (COVID-19): Dec. 2019
T/F: Legionnaire's disease is likely underdiagnosed
TRUE!
T/F: sore throats caused by bacteria are MORE painful than those caused by viruses (and more likely to be accompanied by fever, headache, and nausea)
TRUE!
T/F: legionnaire's disease and Pontiac fever are known as legionnellosis (and can be referred to as legionellosis)
TRUE! These are two sub-types of legionellosis
T/F: viral particles can remain viable on surfaces such as plastic, for up to 3 days
TRUE! This is indirect transmission via a fomite
T/F: white blood cells are a type of macrophage
TRUE! This is what legionella target within our bodies
T/F: legionella is on the rise in the US
TRUE! This may be due to: better identification of microbe, increasing older population, and also COVID playing a role in the increase
T/F: in early 2000s, Measles was declared to be nearly eradicated within the US, but then spikes have occurred since and now Measles has made a come-back and now still seen
TRUE!!
T/F: measles are still endemic to large parts of the world
TRUE!!
What is the defining characteristic of streptococcus?
The chain (phenotype)
Legionella infects ________ in humans
The macrophages
What is the main cause of fatality when considering patients with legionellosis?
The pneumonia that results is what leads to death
Treatment and complications of Pontiac fever
Typically self-limiting and resolves on it's own NO prescriptions or antibiotics
Someone isn't infectious w/COVID when...?
When the person doesn't shed the virus anymore (which can be indicted by a lack of symptoms)
Where was COVID first observed and isolated? When?
Wuhan, China; December 2019
Pontiac fever - clinical features, pneumonia, pathogenesis, incubation period, % become ill when exposed to source of legionella, treatment, isolation of organism, and outcome
clinical features - a milder illness without pneumonia (a flu-like illness, often w/fever, chills, headache, myalgia, fatigue, malaise) pneumonia - No pathogenesis - possible an inflammatory response to endotoxin (of legionella) incubation period - 24-72 hours after exposure % become ill when exposed to source of legionella - greater than 90% treatment - supportive care - because illness is self-limiting isolation of organism - never demonstrated outcome - case-fatality rate extremely low, hospitalization uncommon
Legionnaire's disease - clinical features, pneumonia, pathogenesis, incubation period, % become ill when exposed to source of legionella, treatment, isolation of organism, and outcome
clinical features - fever, myalgia, and cough (additional symptoms: shortness of breath, headache, confusion, nausea, diarrhea) pneumonia - Yes pathogenesis - replication of organism (within amoeba) incubation period - 2-10 days after exposure % become ill when exposed to source of legionella - less than 5% treatment - antibiotics (quinolones, macrolides) isolation of organism - possible outcome - case-fatality rate 10%, 25% for healthcare-associated, hospitalization common
Diagnosis methods for Pontiac fever (2)
same as legionnaire's disease !! 1) urine test (antigen test) — immunologic method 2) lab test involving sample of sputum (phlegm) or washing from lung — phenotypic method that may take longer to develop
Genome type of Measles
ssRNA and UNsegmented
Official name of COVID-19. Who named it and when?
"Severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2) World Health Organization (WHO); in January 2020
Hantavirus (Community-Acquired. Pneumonia) (where it was discovered/when, the family belongs to, associated w/what animal + humans)
- 1993: Four Corners Area - cluster of unusual cases of severe lung edema among HEALTHY young adults - Bunyaviridae family (enveloped virus) - associated w/presence of MICE in close proximity w/humans = transmitted via airborne dust (cleaning) contaminated w/urine, feces, or saliva of infected rodents - other fact: more rain can be associated with higher viruses amongst humans (Hantavirus)
Pharyngitis: Streptococcus Pyogenes — Transmission and Epidemiology (% caused by it, how it's transmitted, how many serotypes exist, other facts)
- 30% of sore throats may be caused by s. Pyogenes - transmission via respiratory droplets or direct contact w/mucus secretions - 80+ serotypes of s. Pyogenes exist - immunity is serotype specific - Carried as "normal" biota by 15% of the pop. - humans = only significant reservoir - transmission human to human is more likely to come from someone who is carrier (unlike those suffering from the active disease)
Subacute sclerosing panencephalitis (caused by, degeneration of, occurrence, how virus is defective, causes?, leads to ?)
- Caused by defective MEASLES virus - progressive neurological degeneration of cerebral cortex/white matter/brain stem - occurrence: 1 in less than 1,000 children (before getting vaccinated) - involves a defective virus = unable to form a capsid/released from an infected cell - spreads unchecked through the brain via cell fusion/destroying neurons and accessory cells + breaking down myelin - causes profound intellectual/neurological impairment - eventually leads to coma + death
healthcare-associated pneumonia (% hospitalized, mortality rate, most commonly associated with ..?)
- Eighty-six percent of nosocomial pneumonias are associated with mechanical ventilation and are termed ventilator-associated pneumonia (VAP). Between 250,000 and 300,000 cases per year occur in the United States alone, which is an incidence rate of 5 to 10 cases per 1,000 hospital admissions" - mortality rate: 30-50% - commonly associated w/mechanical ventilation (via an endotracheal or tracheostomy tube) = those on ventilators are more likely to get healthcare-associated pneumonia
Measles - Prevention
- MMR vaccine - live, attenuated measles virus (that confers protection for up to 20 yrs) - Recommended for healthy children aged 12-15 months, w/booster before child enters school
Measles symptomology
- acute infection - conjunctivitis (reddening of the eyes) - fever (relatively high) - maculopapular rash (look at picture) - Koplik's spots - sore throat - dry cough *not a lot of phlegm* - headache - lymphadenitis (swelling of the lymphnodes)
Mycoplasma pneumoniae (what type of pneumonia, cell wall (?), and treatment)
- atypical pneumonia - lack of cell wall (NO antibiotics used bc no cell to target) - treatment is supportive (for the symptoms) because NO ANTIBIOTICS are utilized
Measles - culture and diagnosis
- clinical presentation (rash/fever/cough/koplik's spots, etc - ELISA to test for IgM (antibody) to measles antigen = which is a serological test
Streptococcus (facts)
- cocci - non-motile (NO flagella) - pairs or chains - facultative anaerobe (can live WITH and WITHOUT oxygen) - catalase negative - hemolytic - capsule (can evade the immune system easier bc protected against macrolides) - Group A strep - Group B strep - non-beta-hemolytic
Pneumonia (what it is, what happens in the lungs, what causes it , relation to children)
- inflammatory response within respiratory tract - inflammatory condition of the lungs in which fluid fills the alveoli (therefore lowers body's ability to get oxygen!!) - wide variety of microbes can cause pneumonia (microbes that have characteristics that allow it to penetrate/survive in lower respiratory tract AND avoid phagocytosis or avoid being killed once phagocytes) - more children die of pneumonia than ANY other infectious disease
Viral cycle of Measles (5)
1) Early Infection - about 2 days after the virus enters body = infects lymph nodes - primary viremia 2) Spread - 3-4 days after infection, blood vessels carry virus-laden cells throughout the body - secondary viremia = leads to rash 3) Early Symptoms - 7-10 days after infection, coughing/sneezing/fevers emerge after viral loads peak. 4) Rash - 12-14 days after infection, red bumps start to spread across the skin - Rash starts at the face/head THEN spreads to the rest of the body 5) Recovery - memory immune cells are depleted by the infection
Measles Key take always (4)
1) Humans - only reservoir 2) transmission via Respiratory droplets/aerosols — Airborne 3) temporal pattern peak = late winter/spring 4) communicable 4 days before to 4 days after RASH onset !
Distinct illnesses of Legionellosis (3)
1) Legionnaire's Disease 2) Pontiac Fever 3) Extrapulmonary legionellosis
Other human coronaviruses (3 examples)
1) MERS-CoV (the Beta coronavirus that causes Middle East Respiratory Syndrome, or MERS) 2) SARS-CoV (the Beta coronavirus that causes severe acute respiratory syndrome, or SARS) 3) SARS-CoV-2 (the novel coronavirus that causes coronavirus disease 2019, or COVID-19)
Types of rashes (6)
1) Macule - spot, FLAT (discoloration) - less than 1 cm in size 2) Papule - spot, ELEVATED (red, pink, purple) - less than 1 cm in size 3) Vesicle - raised - less than 0.5 cm in size - fluid containing (clear) 4) Bullae - greater than 0.5 cm in size 5) Nodule - solid - deeper into tissue 6) Pustle - small - less than 1 cm in size - elevated - fluid filled (cloudy - pus) —> dead cells = neutrophils
COVID testing (3) (take a look at the advantages/disadvantages on the picture)
1) PCR test - amplifies and detects viral genetic material (RNA) if present in a person's secretions collected w/a swab - molecular/genotypic 2) antigen test - detects viral proteins (those that act as antigens) vs. genetic material - serological test 3) antibody test - blood test that determines the presence of antibodies that appear 5+ days post-infection - determine if an individual has had a past infection
COVID is comprised of four main structural proteins, name them
1) spike (S) glycoproteins 2) envelope (E) glycoproteins 3) membrane (M) glycoproteins 4) nucleocapsid (N) proteins
Vaccine Testing Process (4)
1) Preclinical - Scientist test new vaccine on cells, then give to animals (mice or monkeys) - see if produces an immune response 2) Phase 1 - scientists give vaccine to small number of people - test safety + dosage + confirm vaccine stimulates the immune system 3) Phase 2 - scientists give vaccine to hundreds of people (split into groups, such as children and the elderly) - see if vaccine acts differently in various groups + test vaccine safety and ability to stimulate immune response 4) Phase 3 - scientists give the vaccine to thousands of people - wait and see how many become infected, compare w/volunteers who received a placebo vaccine
Infectious Diseases of the Respiratory System (10) and WHAT they are caused by
1) Sinusitus - various bacteria + various fungi 2)Rhinitis - 200+ viruses 3) Diphtheria - corynebacterium diphtheriae 4) Influenza - Influenza virus A/B/C 5) Pneumonia - streptococcus pneumoniae, legionella, mycoplasma pneumoniae, pseudomonas aeruginosa, acinetobacter baumannii, hantavirus, histoplasma capsulatum, pneumocystis jirovecii 6) Otitis Media - streptococcus pneumoniae, other bacteria 7) Pharyngitis - streptococcus pyogenes, viruses 8) Whooping Cough - bordetella pertussis 9) Respiratory Syncytial Virus - RSV 10) Tuberculosis - Mycobacterium tuberculosis
Public Health Pandemic Control Measures (4)
1) Testing (the population w/speed and accuracy) 2) Isolation (of infected individuals) 3) contact tracing (identifying those who have been exposed to the virus) 4) quarantine (Restricting movement of those who are exposed)
Severe complications of Measles in children + Adults (5)
1) about 1 in 5 UNvaccinated ppl in US who get measles gets hospitalized 2) as many as 1 out of every 20 children w/measles gets pneumonia (the most common cause of death from measles in young children !!) 3) about 1 child out of every 1,000 who gets measles will develop encephalitis (swelling of the brain) = lead to convulsions + can leave the child deaf or w/intellectual disability 4) Nearly 1 to 3 of every 1,000 children infected w/measles will die from respiratory + neurological complications 5) measles may cause pregnant women who have NOT had the MMR vaccine may give birth prematurely or have a baby w/low birth weight
Risk Factors for Legionella pneumonia (8)
1) age ≥ 50 years of age — (higher risk for immune system disorders) 2) smoking (current or historical) — (cilia within the lungs aren't able to clear respiratory tract of pathogens like legionella pneumonia) 3) chronic lung disease — (such as emphysema (asthma) or COPD) 4) Immune system disorders due to disease or medication 5) underlying illness — (such as diabetes, renal (kidney) failure, or hepatic (liver) failure 6) recent travel w/an overnight stay outside of the home, including a stay in a healthcare facility — (esp w/places w/water-coolant systems) 7) exposure to hot tubs 8) systemic malignancy
Replication cycle of legionella pneumophila in amoeba (8)
1) attachment and entry 2) establishment and differentiation 3) differentiation and replication (within the ER) 4) differentiation 5) maturation 6) egress (exit) 7) cycle reinitiation 8) passage through ciliates
Infection cycle of legionella pneumophila in macrophages (4)
1) attachment and entry 2) legionella within existing vesicle (the vesicle is taken over by the legionella pneumophila to replicate) 3) replication 4) microbes egress (infect neighboring cells)
Treatment for COVID (2)
1) convalescent plasma - extracting plasma from recovered patients, donating it to sick individuals - FDA allowed treatment of this type in March 2020 for individuals suffering from life-threatening COVID-19 2) Monoclonal antibodies - regeneron - prevent attachment to host cells
Signs and symptoms of legionellosis (5)
1) cough 2) shortness of breath 3) fever 4) muscle aches 5) headaches
Signs and symptoms of COVID (11)
1) fever or chills 2) cough (dry cough) 3) shortness of breath or difficulty breathing 4) fatigue 5) muscle or body aches (myalgia) 6) headache 7) new loss of taste or smell 8) sore throat 9) congestion or runny nose 10) nausea or vomiting 11) diarrhea
Treatment and complications of legionnaire's disease (3)
1) levofloxacin + azithromycin (tetracyclines) 2) lung failure — failure to get oxygen (due to pus, etc in lungs) 3) death
Portals of entry for COVID (3)
1) nasal and oral passages (of the respiratory tract) 2) nasolacrimal duct 3) oral cavity + esophagus
Indications for legionnaire's disease testing (6)
1) patients who have failed outpatient antibiotic treatment for community-acquired pneumonia 2) painters w/severe pneumonia (esp those requiring intensive care) 3) immunocompromised patients w/pneumonia (overall heath status important!) 4) patients w/travel history (patients who have traveled away from their home within the last 10 days before onset of illness, esp to places using water-coolant systems) 5) all patients w/pneumonia in a place of an outbreak of legionnaire's disease 6) patients at risk for legionnaire's disease w/healthcare-associated pneumonia (pneumonia w/onset of 48 hours or more after admission)
Ideal conditions for the spread of the virus (provided on the slide, 5)
1) population-dense areas 2) large public gatherings 3) prisons 4) cruise ships 5) senior living centers
Streptococcus infections lead to (3 outcomes)
1) rheumatic fever - immune response to bacterial infection = heart targeted due to immune response 2) Glomerulonephritis - immune response targets other areas of body due to response 3) scarlet fever - scarletina - defining characteristics = rash over body, strawberry tongue *Immune system responds to microbe and since our cells appear similar to immune system = our tissues are thus targeted
Examples of common cold causative agents (4)
1) rhinovirus (99 serotypes) 2) coronavirus 3) adenovirus 4) respiratory syncytial virus (RSV)
Causes and common sources of infection (6)
1) shower heads and sink facets — (creates smaller droplets/aerosols that are inhaled/biofilm contains organisms that are able to be spread through the shower head) 2) cooling towers — (structures that contain water and a fan as part of a centralized air-cooling systems for building/industrial processes == creates vapors/aerosols that people within the building inhale) 3) hot tubs that aren't drained after each use — (or poorly maintained) 4) decorative fountains and water features — creates aerosols that people nearby are to inhale 5) hot water tanks and heaters 6) large plumbing systems
Targets for COVID-19 (2)
1) spike (S) glycoproteins; prevents attachment of the virus 2) 16 nonstructural proteins (that the genome ssRNA encodes for); prevents viral replication, maturation, and release
Community-Aquired pneumonia (causative organisms - 6)
1) streptococcus pneumoniae - 40% of all community-acquired bacterial cases 2) Legionella -less common - causes serious disease 3) Haemophilus influenzae - once was a major cause (HIB vaccine reduced its incidence) 4) Mycoplasma pneumoniae and Chlamydophila pneumoniae - walking pneumonia 5) Histoplasma capsulatum - fungus 6) Hantavirus
Pneumonia (name the 7 causative agents AND study the chart !!)
1) streptococcus pneumoniae 2) legionella species 3) mycoplasma pneumoniae 4) hantavirus 5) histoplasma capsulatum (fungi) 6) pneumocystis jiroveci (fungi) 7) respiratory viruses
Diagnosis methods for legionnaire's disease (2)
1) urine test (antigen test) — immunologic method 2) lab test involving sample of sputum (phlegm) or washing from lung — phenotypic method that may take longer to develop
Common human coronaviruses (4 specific strain names given and the type of coronavirus) that cause the common cold
229E (alpha) NL63 (alpha) OC43 (beta) HKU1 (beta)
Pharyngitis (three == causative organisms, common modes of transmission, virulence factors, culture/diagnosis, prevention, treatment, distinctive features, epidemiological features)
AGENTS (causative agents): 1) streptococcus pyogenes (bacterial) - droplet/direct contact - LTA, M protein, hyaluronic acid capsule, superantigens, induction of autoimmunity - beta-hemolytic on blood agar, sensitive to bacitracin, rapid antigen tests - hygiene practices - penicillin, cephalexin in pencilin-allergic - generally more severe than viral pharyngitis - US: 20-30% of all cases of pharyngitis 2) fusobacterium necrophorum (bacterial) - opportunistic - invasiveness, endotoxin, leukotoxin - growth on anaerobic agar - hygiene practices - penicillin + metronidazole or clindamycin - common in adolescents and young adults, neck swelling common; infections spread to cardiovascular system or deeper tissues - US: 10-30% of cases 3) viruses (ex: adenovirus and rhinovirus) - all forms of contact - NA - goal is to rule out s. Pyogenes, further diagnosis usually not performed - hygiene practices - symptom relief only - hoarseness frequently accompanies virtual pharyngitis - ubiquitous; responsible for 40-60% of all pharyngitis
Is Pontiac fever considered more an inflammatory response or a disease?
An inflammatory response because the microbe is not able to be isolated from patient and the inflammatory response is what is most likely causing person to be ill and have symptoms
What is a cytokines storm? What leads to one?
An overreaction by the immune system, causing immune cells to attack healthy tissues Extensive exocytosis of virus particles leads to apoptosis and death of alveolar cells; non-specific immune cells release chemokines = stimulate a targeted attack on the infected cells, crippling normal cell function... then in critical cases a cytokine storm occurs
The Common Cold (causative organisms, common modes of transmission, virulence factors, culture/diagnosis, prevention, treatment, epidemiological features)
Causative organisms: approx. 200 viruses Most common modes of transmission: indirect contact, droplet contact Virulence factors: attachment proteins; most symptoms induced by host response Culture/diagnosis: not necessary Prevention: hygiene practices Treatment: for symptoms only (ex: meds for myalgia/runny nose/cough) Epidemiological features: highest incidence among preschool/elementary schoolchildren w/average of 3-8 colds a year and adults/adolescents 2-4 colds a year
In, general people (DO/DO NOT) spread legionnaire's disease to other people
DO NOT; however this may be possible under rare circumstances
Where does the coronavirus get it's name? (The corona part)
From it's characteristic of looking like a crown ("corona") - due to the S proteins protruding from it's surface
Example of a vaccine given too early
ROTAVIRUS Vaccine (rotavirus = an intestinal pathogen) - negative side-affects = high morbidity although virus was not high in frequency (within the vaccine) SIDE NOTE: DENGUE VIRUS as well! - vaccine trial showed that targeting one serotype = higher ability for the three other serotypes to allow infection (and adverse reactions)
Stages of COVID (3)
Stage 1: asymptomatic state - incubation time - median 4-5 days, range 2-14 days - virus detected by a nasal swab and shed by the host in droplets - virus propagates, mild innate immune response initiated Stage 2: upper airway and conducting airway response - robust immune response - clinical manifestations of disease appear 2-14 days post-exposure and include symptoms - up to 80% of COVID-19 cases will be either asymptomatic or will arrest at this stage Stage 3: hypoxia, progression to acute respiratory diseases syndrome (ARDS) within 8-12 days - critical care/hospitalization necessary - approx. 15% of patients require oxygen and 5% ventilation - manifestations: pneumonia, difficulty breathing, persistent chest pain/pressure, confusion, inability to stay away, bluish lips/skin - oxygen levels fall as lungs fill w/fluid, white blood cells, mucus, and cellular debris - cytokine storm = drop in blood pressure, leaky blood vessels, formation of blood clots, organ failure
T/F: viral particles have been found in fecal samples and there is accumulating evidence for fecal-oral transmission
TRUE!
T/F: it is possible to feel great and WITHOUT symptoms and STILL infect others
TRUE! As long as you are shedding the virus to possibly contaminate others, you are contagious
T/F: Measles erases immune "memory" for other diseases
TRUE! Measles can expose you to other diseases and reinfect body
T/F: pneumonia can be secondary effect of influenza
TRUE!!
T/F: As of May 2020, there are no FDA-approved drugs for COVID
TRUE; although therapies have been suggested as being hopeful - Remdesivir (antiviral drug for SARS/MERS which are also coronaviruses; targets RNA-dependent RNA-polymerase therefore the VIRAL REPLICATION) - chloroquine/hydroxychloroquine (antimalarial drugs targeting viral entry/PH levels preventing acidification) — NOT shown to be very significant in helping
T/F: COVID may have a role in the estimated increase of legionnaire's diseases.
TRUE; this is because of the sitting water within the water fountains that may be harboring legionella pneumophila that would then be exposed to ppl once the water fountains are opened up again.
How does COVID manifest inside the human body?
The proteins are translated (from the RNA within the virus), which make polyproteins within the body
What is the purpose of the vesicle/ why does legionella pneumophila prefer this?
This is because the vesicle protects the microbe because the white blood cells (macrophages) aren't able to get ahold of the microbe/combat it
