HLTH 2501: infectious diseases (respiratory) Flashcards
what is the common cold?
a viral infection that affects the upper respiratory tract
common pathogens causing the common cold
most often it is a rhinovirus, but may also be an adenovirus, parainfluenza virus, or coronavirus; however, there are more than 200 possible causative organisms
how is the common cold spread?
via respiratory droplets (these are either inhaled or spread by secretions on hands or contaminated objects)
why is the common cold so contagious?
because the virus is shed in large numbers from the infected nasal mucosa and it can also survive for several hours outside of the body
signs of a common cold
red nose, swollen pharynx, nasal congestion, watery eyes sneezing, mouth breathing, sore throat, headache, slight fever, malaise, cough, and may cause secondary infections
rhinorrhea
mucus or snot dripping out of the nose
what are common secondary infections of the common cold?
pharyngitis, laryngitis, or acute bronchitis,
treatment for the common cold
acetaminophen for fever and headache, decongestants, antihistamines, humidifiers, vitamin C, and antibiotics if a secondary infection has developed
another name for strep throat
pharyngitis
sinusitis
is usually a bacterial infection secondary to a cold or an allergy that has obstructed the drainage of one or more of the paranasal sinuses into the nasal cavity
common causative organisms for sinusitis
pneumococci, streptococci, or hemophilus influenza, as well as viruses or fungi
signs of sinusitis
pain in the facial bones (feels like a headache or toothache), nasal congestion, fever, and sore throat
why do you feel pain in the facial bones during sinusitis?
as exudate accumulates, pressure builds up inside the sinus cavity causing pain
diagnosis for sinusitis
radiograph or transillumination
treatment for sinusitis
decongestants, analgesics, and antibiotics
laryngotracheobronchitis
is a common viral infection in children that begins as an upper respiratory infection. causing inflammation of the mucosa and trachea, obstructing airflow
common causative agents of laryngotracheobronchitis
parainfluenza viruses and adenoviruses
signs of laryngotracheobronchitis
nasal congestion, cough, swelling, exudate, and inflammation, which lead to barking cough (croup) and hoarse voice
treatment for laryngotracheobronchitis
humidifiers, shower, or croup tent, but is usually self-limited and recovery is quick
epiglottitis causative organism
haemophilus influenzae
epiglottitis
is an acute bacterial infection common in children 3-7, causing swelling of the larynx, supraglottic area, and epiglottis
signs of epiglottitis
round, red ball obstructing the airway, fever, sore throat, inspiratory stridor (high-pitched sound), refusing to swallow, child takes a sitting position or tripod position with the mouth open, saliva drooling, and pallor
treatment for epiglottitis
oxygen and antimicrobial therapy, and sometimes tracheotomy
influenza
is a viral infection of both the upper and lower respiratory tracts and has three types (A,B,C)
type A influenza
is the most prevalent pathogen for influenza
flu vs cold
flu has a sudden onset with marked fever, fatigue, and body aching but both may cause secondary infections to develop
common secondary infection of influenza
pneumonia
treatment for influenza
antiviral drugs like amantadine, zanamivir, or oseltamivir
incubation period for influenza
1-4 days
what is scarlet fever caused by?
group A beta-hemolytic streptococcus pyogenes
symptoms of scarlet fever
fever, sore throat, chills, vomiting, abdominal pain, malaise, strawberry tongue, and a fine rash on the chest, neck, groin, and things
strawberry tongue
common in scarlet fever and is caused by the exotoxin produced by the bacteria
treatment for scarlet fever
antibiotics
upper respiratory tract infections
scarlet fever, influenza, common cold, epiglottitis, sinusitis, and laryngotracheobronchitis
bronchiolitis
is a common viral infection in young children aged 2 to 12 months
causative organism for bronchiolitis
the respiratory syncytial virus (RSV), a myxovirus
how is bronchiolitis transmitted?
oral droplets
what does the bronchiolitis infection cause?
necrosis and inflammation in the small bronchi and bronchioles, along with edema, increased secretions, and reflex bronchospasm leading to obstruction of the small airways
3 respiratory infections that affect young children
laryngotracheobronchitis, bronchiolitis, and epiglottitis
signs of bronchiolitis
wheezing, dyspnea, rapid and shallow respirations, cough, rales, chest retractions, fever, and malaise
treatment for bronchiolitis
RSV immunoglobulin serum (palivizumab) which is an RSV monoclonal antibody
pneumonia
is often a secondary infection to others and is at risk for developing when fluid pools in the lungs or when cilia function is reduced; causative agent can be a virus, bacterium, or fungus
how is pneumonia classified?
based on the causative agent, anatomic location of the infection, pathophysiologic changes, or epideminologic data
lobar pneumonia
is often caused by a bacterium, often staphylococcus aureus or legionella
pneumonia vaccines
there are 7 available for the most common agents are is often given to those with chronic respiratory or cardiovascular disease, as well as those 65+
what are common causative organisms of pneumonia for immunosuppressed individuals?
candida or pneumocystis carinii
viral pneumonia
often causes changes in the interstitial tissue or alveolar space
pneumococcal pneumonia
alveoli appears inflamed and is filled with exudate, resulting in a solid mass in a lobe
word for hospital acquired infections
nosocominal
what are causative agents in nosocomial pneumonias?
usually are gram-negative bacterias like klebsiella pneumoniae pr pseudomonas aeruginosa
community-acquired pneumonia
viral or bacterial
lobar pneumonia causative agent
S pneumoniae (pneumococcus)
3 types of pneumonia
lobar, interstitial, or bronchial
lobar pneumonia
infection if localized in one or more lobes and sometimes colonizes the nasopharynx
lobar pneumonia development
congestion first develops due to inflammation and exudate in the alveoli, then a lobe called a consolidation develops, then RBC breakdown, and infection may spread into the pleural cavity causing empyema; hypoxia may also develop due to filling of the alveoli reducing gas exchange
consolidation
is a mass of RBCs, neutrophils, and fibrin that accumulates in the alveolar exudate in lobar pneumonia
sputum for lobar pneumonia
is rusty due to RBCs in the exudate
empyema
infection of the pleural cavity resulting from spread of lobar pneumonia; can cause adhesion between the layers if not resolved quickly
how is lobar pneumonia diagnosed?
chest X-rays and culture samples of the sputum
signs of lobar pneumonia
hypoxia, sudden onset, high fever, chills, fatigue, leukocytosis, dyspnea, tachypnea, tachycardia, pleuritic pain, rales heard, productive cough with rust coloured sputum, and confusion and disorientation in severe cases
other name for lobar pneumonia
pneumococcal pneumonia
what can the oxygen deficit in lobar pneumonia result in?
metabolic acidosis
treatment for lobar pneumonia
antibacterials like penicillin, in combination with fluids, drugs to reduce fever, and O2 administration
bronchopneumonia
occurs as a diffuse pattern of infection in both lungs, often of the lower lobes; infection starts in the bronchial mucosa and spreads into the alveoli
how does bronchopneumonia causative organism begin infection?
often when there is pooled secretions in the lungs, common in immobilized patients
hypostatic pneumonia
develops in immobilized patients
signs of bronchopneumonia
gradual onset with fever, cough, rales, and cough with purulent sputum (yellowish or green)
legionnaires disease causative agent
a gram-negative bacteria called legionella pneumophila; this microbe thrives in warm, moist environments, often in spas or hospitals
why is legionnaires disease difficult to identify?
because the microbe resides in pulmonary macrophages
legionnaires disease symptoms if untreated
severe congestion and consolidation, with necrosis in the lungs
primary atypical pneumonia
differs from typical types due to the causative organism (viral or mycoplasmal) and intestinal inflammation
mycoplasma pneumoniae
is a small bacterium that lacks a cell wall and varies in shape; is normally found in the upper respiratory tract and is transmitted by aerosol
mycoplasma pneumonia signs
frequent cough
treatment for mycoplasma pneumonia
erythromycin or tetracycline therapy
viral pneumonia causative agents
is caused by influenza A and B, as well as adenoviruses and RSV
viral pneumonia development
begins gradual with inflammation in the mucosa of the upper tract, then descending to involve the lungs
signs of viral pneumonia
unproductive cough, hoarseness, sore throat, headache, mild fever, and malaise
chlamydial pneumonia
is caused by the organism Chlamydia pneumoniae and is considered to be the cause of PAP and pharyngitis
pneumocystis carinii pneumonia
is a type of atypical pneumonia and occurs as an opportunistic infection in those with AIDS and infants
how does pneumocystis carinii pneumonia develop?
a fungus is inhaled and attaches to alveolar cells, causing necrosis and diffuse interstitial inflammation; the alveoli then fill with exudate and fungi
signs of pneumocystis carinii pneumonia
difficulty breathing and a nonproductive cough
treatment for pneumocystis carinii for AIDS patients
prophylactic drugs like sulfamethoxazole-trimethoprim
what is COVID-19 caused by?
SARS-CoV-2 virus
unique pathophysiological signs of COVID-19
firm attachment to lung cells and the triggering of a cytokine storm
COVID-19 virus
is an enveloped, single-stranded, positive sense RNA virus called SARS-CoV-2 and belongs to the coronaviridae family
coronaviridae family
include COVID-19, SARS, and middle east respiratory syndrome virus
cytokine storm for COVID-19
not fully understood but results in severe inflammation of the lungs, resulting in pneumonia and lung tissue damage
signs in critical COVID-19 cases
acute respiratory distress syndrome, shock, encephalopathy, myocardial injury, heart failure, coagulation dysfunction, and acute kidney injury
signs of COVID-19
fever or chills, coughing, sneezing, difficulty breathing, fatigue, temporary loss of taste, muscle aches, headache, sore throat, nausea, vomiting, congestion, and confusion in older individuals
testing for COVID-19
antibody testing (presence of antibodies) and diagnostic (looking for presence of viral genetic material)
drugs for COVID-19
malaria drug hydroxyquinoline combined with antibiotics and remdesivir
SARS acronym
severe acute respiratory syndrome
SARS
is an acute respiratory infection that was first diagnosed in 2002
causative microbe for SARS
SARS-CoV a coronavirus which is a RNA virus
how is SARS transmitted?
via respiratory droplets
signs of SARS
first stage is flulike symptoms (fever, headache, myalgia, chills, anorexia, dirrahea) followed by a dry cough and dyspnea
serum levels in those with SARS
low O2, low WBCs, low platelets, increased C-reactive proteins, and elevated liver enzymes
treatment for SARS
antiviral ribavirin and the glucocorticoid methylprednisolone
tuberculosis
is increasing globally again, particularly common amongst AIDS patients in Africa and among those in poverty and overcrowding
what is the causative agent in tuberculosis?
mycobacterium tuberculosis which primarily affects the lungs, but the pathogen may also invade other organs; this bacterium is resistant to many disinfectants and can survive in dried sputum for weeks
tuberculosis vs immune system
the cell wall of the mycobacterium protects it
primary infection of tuberculosis
is asymptomatic and occurs when the microorganisms first enter the lungs, are engulfed by macrophages and cause a local inflammatory reaction; this then forms a granuloma, then necrosis, and a calcified lesion that contains the bacilli until it is active again
granuloma in tuberculosis
forms due to lymphocytes and macrophages clusters together at the site of inflammation; this then forms the tubercle which contains the bacilli; in the center of this, caseation necrosis will develop
ghon complexes
calcified lesions in healthy individuals caused by tuberculosis in the lungs and lymph nodes
Mantoux tuberculin test
is a hypersensitivity reactions that is used to detect exposure to the bacillus; the individual will produce a positive skin reaction, which is a hard, raised, red area
testing for secondary phase of tuberculosis
mantoux tuberculin tests, X-ray, and sputum culture; sometimes a CT is used
miliary tuberculosis
aka extrapulmonary TB; is a rapidly progressive form in which multiple granulomas affect large areas of the lungs and rapidly disseminate into the circulation and to other tissues (often bone or kidney)
secondary tuberculosis
is the stage of active infection and arises years after primary infection when the bacilli, hidden in the tubercles are reactivated usually due to decreased host resistance
what occurs in the secondary phase of tuberculosis?
larger areas of necrosis form, cavitation, hemoptysis, and infection may spread
cavitation
is the formation of a large open area in the lung and erosion into the bronchi and blood vessels; occurs in secondary phase of tuberculosis
how is tuberculosis transmitted?
oral droplets or digestion from unpasteurized milk
signs of tuberculosis
only symptoms in secondary phase and are anorexia, malaise, fatigue, weight loss, low-grade fever, night sweats, prolonged cough, and purulent sputum that often contains blood
testing for the primary phase of tuberculosis
a tuberculin test
treatment for primary phase of tuberculosis
drugs like isoniazid and rifampin; these can prevent the disease from becoming the fully active form
treatment for secondary phase of tuberculosis
drugs like isoniazid, rifampin, and streptomycin; treatment usually is 6 months to a year
histoplasmosis
is a fungal infection that is commonly opportunistic and has effects similar to tuberculosis
causative organism in histoplasmosis
the fungus histoplasma capsulatum and is often found as a parasite inside macrophages
where is histoplasmosis common?
the midwestern US
how is histoplasmosis transmitted?
as a spore being inhaled on dust particles
how is histoplasmosis similar to tuberculosis?
it has a primary asymptomatic phase, followed by a second stage of infection that involves granulomas and necrosis in the lungs, and possibly spread to other organs
signs of histoplasmosis
cough, fatigue, fever, and night weats
how is histoplasmosis diagnosed?
via a skin test and a culture to confirm this
treatment for histoplasmosis
antifungal agent amphotericin B
anthrax
ia a bacterial infection of the skin, respiratory tract, and GI tract in humans and catle
causative organism for anthrax
gram-positive bacillus that forms grayish-white spores that can remain viable for long periods of time
cutaneous form of anthrax signs
blisters and bumps that may itch, swelling around the sore, painless open skin sore with a black centre, and sores often develop on the face, neck, arms, or hands
inhalation form of anthrax
fever and chills, chest discomfort, dyspnea, cough, confusion, dizziness, nausea, vomiting, headache, sweats, extreme tiredness, and body aches
GI form of anthrax
fever, chills, swelling of neck glands, sore throat, painful swallowing, hoarseness, nausea, vomiting with blood, headache, flushing face and red eyes, fainting, and abdominal swelling
how is anthrax treated?
with the antimicrobial ciprofloxacin along with the administration of anthrax antitoxin
