chapter 22

common cold

sneezing, rhinorrhea, congestion, sore throat, headache, malaise, cough, runny nose

diagnosis, treatment, prevention

• signs and symptoms are usually diagnostic

• pleconaril can reduce duration of symtoms

• hand antisepsis is important prevention measure

influenza

fever, rhinorrhea, headache, body aches, fatigue, dry cough, pharyngitis, congestion, myalgia

sudden fever distinguishes flu from common cold

infection provides some immunological protection from similar strains

concerns that changes in type A influenza viruses may cause another major pandemic

prevented with a immunization with a multivalent vaccine

strep throat

fever, red and sore throat, swollen lymph nodes in the neck

viral pneumonia

fever, chills, mucus-producing cough, headache, body aches, fatigue

bacterial pneumonia

fever, chills, congestion, couch, chest pain, rapid breathing, and possible nausea and vomiting

• lung inflammation accompanied by fluid-filled alveoli and bronchioles

• described by affected region or oragnism causing the disease

  • lobar

  • mycoplasmal

  • healthcare-associated

• are the most serious and mose frequent in adults

bronchitis

mucus-producing couch, wheezing

inhalation anthrax

fever, malasie, couch, chest discomfort, vomiting

coronavirus

high fever (> 38 degrees Celsius), cough, shortness of breath

streptococcal respiratory diseases

signs

• pharyngitis

  • sore throat and difficulty swallowing

• often accompanied by fever, malaise, and headache

• laryngitis and bronchitis can occur if infection spreads to lower respiratory tract

• complications including scarlet fever, rhematic fever, and actue glomerulephritis occur in some cases

Epidemiology

• spread via respiratory droplets

• occur most often in winter and spring

diagnosis, treatment, and prevention

• often confused with viral pharyngitis

• oral penicillin is an effective treatment

group A streptococci (s. pyogenes)

the pathogen that causes streptococcal respiratory diseases

• M protrins

• Hyaluronic acid capsule

• streptokinases

• C5a peptides

• pyrogenic toxins

• streptolysins

occurs when normal microbiota are depleted, large inoculum us introduced, or adaptice immunity is impaired

diphtheria

signs

• sore throat, localized pan, and fever

• presence of pseudomembrane that can obstruct airways

dianosis, treatment, prevention

• diagnososis is based on presence of a pseudomembrane

• confirmed by elek test

• treatment with antitoxin and antibiotics

• immunization is effective prevention

corynebacterium diptheriae

gram-postive, pleomorphic bacteria

ubiquitous in animals and humans

produces diphtheria toxin

prevents polypeptide synthesis and causes cell death

spread via respiratory froplets or skin contact

symptomatic in immunocompromised or nonimmune individuals

leading cause of death among unimmunized children

elek test

what test confirms diptheria after presence of pseudomembrane is seen x

enteroviruses (rhinoviruses)

the common cause of the common cold

• numerous other viruses cause coldd

• cold viruses replicate at lower temperature of the nasal cavity

• cold viruses replicate in and kill infected cells

lower

is the lower or the upper respitatory system usually axenic,

a bacterial infection of this system can cause life-threatening illness

pneomococcal pnemonia

• fever, chills, congestion, cough, and chest pain

• results in short, rapid breathing

• blood enters the lungs, causing rust-colored sputum

dianosis, treatment, prevention

• diagnosed by identifying diplococci in sputum smears

• penicillin is the drug of choice for treatment

  • some strains are now penicilin resistant

• vaccinationis method of prevention

mycoplasmal pneumonia

fever, malaise, sore throat, and excessive sweating

symptoms may last for weeks

bacteria spread by nasal secretions

most common pneumonia in teenagers and young adults

diagnosis, prevention, treatment

• difficult to diagnose

• treated with erthromycin or doxyxyline

• prevention difficult since infected with individuals may be asymptomatic

mycoplasma pneumoniae

the pathogen that causes mycoplasmal neumonia

virulence factors include adhesion protein

• bacteria colonize and kill epithelial cells

• mucus buildp and colonization by other bacteria

streptococcus pneomoniae

the cause of pneumococcal pneumonia

• virulence factors

  • adhesions

  • capsule

  • pneumolysin

• infection occurs by inhalationof bacteria

• bacterial replication causes damage to the lungs

• pneumococcal IgA protease destroys host secretory IgA

• accounts for most cases of bacterial pneumonia

klebsiella pneumonia

• pneumonia symptoms with bloody sputum and chills

• diagnosed by identifing —- in sputum samples

• treated with antimicrobials

• prevention involved good aseptic technique by health care workers

klebsiella pneumoniae

the pathogen that causes klebsiella pneumonia

• virulence factors include a capsule

• immunocompromised patients at greater risk for infection

Haemophilus influenzae and Staphylococcus aureus

diseases similar to pneumococcal pneumonia

yersinia pestis

causes pneumonia, called pneumonia plague

chlamydophila psittaci

causative agent of pstittacosis

chlamydophla pneumoniae

causes pneumonia, bronchitit, and rhinosinusitis

legionnaires disease

• typical pneumonia symptoms

• pulmonary function can rapidly decrease

the pathogen survives in domestic water sources

elderly, smokers, and immunocompromised individuals are at increased rick of infection

diagnosed with fluorescent antibody staining or serology

quinolones or macrolides are preferred treatment

controlled by reducing bacterial presence in water

leginella pneumophila

the pathogen that causes legionnaires disease

gram negative, aerobic coccobacillus

lives in and kills human cells

• causes tissue damage adn inflammation

tuberculosis

leading disease killer in the world

incidence has declined in the industrialized world

signs

• initially limited to minor couch and mild fever

• symptoms are not always present

one-third of the worlds population is infectd

most deaths occur in Asia and africa

treatment is a combination of drugs, there are resistant strains

tuberculin skin test

what test identifys tuberculosis

chest X-ray images

what can identify tubercles in the lungs

BCG

what is the vaccine that is available where tuberculosis is common

mycobacterium tuberculosis

what is the pathogen that causes tuberculosis

• small bacillus

• presence of mycolic acid gives bacteria unique features

  • slow growth

  • protection from phagocytic lysis

  • intracellular growth

  • resistance to many antimicrobial drugs

• spread via inhalation od respiratory drops

• three types of tuberculosis

  • primary

  • secondary

  • disseminated

pertussis (whooping couch)

initially cold like, than characteristic cough developes

• highly contagious

• bacteria spread through airborne droplets

• bacteria do not survive long outside the body

• considered a re-emerging disease

symptoms are diagnostic

treatment is primarily supportive

prevention is with the DTaP vaccine

bordetella pertussis

the pathogen that causes pertussis (whopping cough)

• gram negative, aerobic, coccobacillus

produces numerous virulence factors

• includes adhesions adn several toxins

progresses through four phases

inhalation anthrax

signs

• initial resembles cold or flu

• progresses ro severe coughing, lethargy, shock, and death

diagnosis based on identification of bacteria in sputum

ealry and aggressive antimicrobial treatment is necessary

vaccine is available to select individuals

bracillus anthracis

the pathogen that causes anthrax

• virulence factors include a capsule and anthrax toxin

• acquored by inhalation of or contact with endospores

oseltamivir and zanamivir

what can be administered early in infection for influenza

mutations in what produce new strains of influenza

• occurs via antigenic drift and antigenic shift

• influenza type A and B are the causative agents

• concern about the fatality accociated with strains similar to those of past pandemics

• virus causes damage to the lung epithelium

• flu patients are susceptible to secondary bacterial infections

type A

concers that chanfes in ___ influenza viruses may cause another major pandemic