Chp 19 pt 2

What is the most dangerous causes of pharyngitis

Streptococcus pyogenes- Group A streptococcus

Corynebacterium diphtheriae

Neisseria gonorrhoeae

What are the possible sequelae of S. pyogenes (group A streptococcus)

Rheumatic fever

Post-streptococcal glomerulonephritis (kindney inflammation; can lead to failure in serious cases)

Scarlet fever

What are the possible sequelae of Corynebacterium diphtheriae (diphtheria)

Myocarditis (heart inflammation)

Neuropathy (damage to peripheral nerves can cause paralysis)

Airway obstruction

What are the possible sequelae of Neisseria gonorrhoeae (gonococcal pharyngitis)

Disseminated Gonococcal Infection ( can spread to joints and skin)

Endocarditis and meningitis can also occur in severe cases.

Infectious diseases of the upper respiratory tract

Common cold. sinusitis, acute otitis media

Common cold

Primarily caused by viruses especially rhinovirus

Common cold transmission

Respiratory droplets, direct contact, contaminated surfaces

Symptoms of common cold

Congestion, runny nose, sneezing, sore throat, cough, mild headache, no or low grade fever

Pathology of common cold

Virus infects nasal and pharyngeal epithelial cells, causing inflammation and mucus production. Self limiting and symptoms last 5-10 days

Sinusitis

Can be viral (more common and follows cold), bacterial, or fungal

Symptoms of sinusitis

Facial pain or pressure, nasal obstruction, loss of smell, fever, headache

Complications of sinusitis

Bacterial sinusitis may lead to orbital cellulitis, meningitis, or brain abscess.

Acute otitis media

Commonly bacterial; viral upper respiratory infections often precede bacterial infection

Epidemiology of otitis media

Most common in children 6 months to 2 years

Symptoms of otitis media

Ear pain, fever, hearing loss, irritability in young children, sometimes associated with upper respiratory symptoms

Complications of otitis media

Tympanic membrane perforation, chronic otitis media, hearing loss

Antigenic drift

Antigens gradually change their amino acid composition resulting in decreased ability of host memory cells to recognize them. This is the reason that a new vaccine is required each year

Antigenic shift

RNA exchange between different influenza viruses. Occurs during co-infection of a host cell. More likely to produce pandemic strains

Discuss the problems associated with MDR-TB and XDR-TB

MDR-TB and XDR-TB don’t respond to the usual TB medicines.

Patients have to take stronger drugs that can cause more side effects.

Treatment takes much longer—up to 2 years or more.

Many people don’t fully recover, and some even die from it.

Difficult to diagnose

Expensive to treat