Common cold (Rhinitis)

Causative organism: Approximately 200 viruses (rhinoviruses, adenoviruses, and coronaviruses)

Mode 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

Sinusitis (virus)

Causative organism: Viruses

Mode of Transmission: Direct contact, indirect contact

Culture/Diagnosis: Culture not usually performed; diagnosis based on clinical presentation

Prevention:Hygiene

Treatment: None

Sinusitis (bacteria)

Causative organism: Various bacteria, often mixed
infection

Mode of Transmission: Endogenous (opportunism)

Culture/Diagnosis: Culture not usually performed;
diagnosis based on clinical presentation, occasionally X-rays or other imaging technique used

Prevention: N/A

Treatment: Recommendation is for no antibiotics unless it remains unresolved for some weeks

Sinusitis (fungi)

Causative organism: Various fungi

Mode of Transmission: introduction by trauma or
opportunistic overgrowth

Culture/Diagnosis: Culture not usually performed;
diagnosis based on clinical presentation

Prevention: N/A

Treatment: Physical removal of fungus; in severe cases, antifungals used

Otis Media (Streptococcus)

Causative organism: Streptococcus pneumoniae

Mode of Transmission: Endogenous (may follow upper
respiratory tract infection by S. pneumoniae or other microorganisms)

Virulence factors: Capsule, hemolysin

Culture/Diagnosis: Usually relies on clinical symptoms and
failure to resolve within 72 hr

Prevention: Pneumococcal conjugate vaccine (PCV13)

Treatment: Wait for resolution; if needed, amoxicillin (high rates of resistance) or amoxicillin + clavulanate or cefuroxime; antibiotic usage recommended for babies less than 6 months old

Otis Media (Candida)

Causative organism: Candida auris

Mode of Transmission: Not known

Virulence factors: Biofilm formation

Culture/Diagnosis: MALDI-TOF or PCR; CDC will identify if requested

Prevention: None

Treatment: Consult with CDC; in Urgent Category in CDC Antibiotic Resistance Report

Pharyngitis (Streptococcus)

Causative organism: Streptococcus pyogenes

Mode of Transmission: Droplet or direct contact

Virulence factors: LTA, M protein, hyaluronic acid capsule, SLS and SLO, superantigens, induction of autoimmunity

Culture/Diagnosis: Beta-hemolytic on blood agar, sensitive to bacitracin, rapid antigen tests

Prevention: Hygiene practices

Treatment: Penicillin, cephalexin in penicillin-allergic

Pharyngitis (Fusobacterium)

Causative organism: Fusobacterium necrophorum

Mode of Transmission: Usually endogenous

Virulence factors: Invasiveness, endotoxin

Culture/Diagnosis: Culture anaerobically; CT scan for
abscess(es)

Prevention: ?

Treatment: Penicillin

Pharyngitis (virus)

Causative organism: Viruses

Mode of Transmission: All forms of contact

Virulence factors: N/A

Culture/Diagnosis: Goal is to rule out S. pyogenes
(and F. necrophorum); further diagnosis usually not
performed

Prevention: Hygiene practices

Treatment: Symptom relief only

Pertussis (Whopping Cough)

Causative organism: Bordetella pertussis

Mode of Transmission: Droplet contact

Virulence factors: FHA (adhesion), pertussis toxin and tracheal cytotoxin, endotoxin

Culture/Diagnosis: PCR or growth on B-G, charcoal, or potato-glycerol agar; diagnosis can be made on symptoms

Prevention: Acellular vaccine (DTaP), azithromycin for contacts

Treatment: Azithromycin; drug-resistant B. pertussis is a
concerning threat on the CDC’s list of antibiotic resistance threats

Respiratory Syncytial Virus Disease

Causative organism: Respiratory syncytial virus (RSV)

Mode of Transmission: Droplet and indirect contact

Virulence factors: Syncytia formation

Culture/Diagnosis: RT-PCR

Prevention: Passive antibody (humanized monoclonal) in high-risk children

Treatment: Ribavirin plus passive antibody in severe cases

Influenza

Causative organism: Influenza A, B, and C viruses

Mode of Transmission: Droplet contact, direct contact, or indirect contact

Virulence factors: Glycoprotein spikes, antigenic drift and shift

Culture/Diagnosis: Gold standard is RT-PCR tests

Prevention: A variety of vaccines are available and should be
received annually

Treatment: Oseltamivir (Tamiflu), baloxavir (Xofluza)

Tuberculosis (Mycobacterium)

Causative organism: Mycobacterium tuberculosis

Mode of Transmission: Vehicle (airborne)

Virulence factors: Lipids in wall, ability to stimulate strong
cell-mediated immunity (CMI)

Culture/Diagnosis: Culture, PCR test (Xpert®), IGRA,
complemented by skin test and chest X-ray

Prevention: Avoiding airborne M. tuberculosis; BCG
vaccine in other countries

Treatment: Isoniazid, rifampin, and pyrazinamide +
ethambutol or streptomycin for varying lengths of time (always lengthy)

Tuberculosis (MDR-TB)

Causative organism: MDR-TB and XDR-TB

Mode of Transmission: Vehicle (airborne)

Virulence factors: Lipids in wall, ability to stimulate strong cell-mediated immunity (CMI)

Culture/Diagnosis: Culture, PCR test (Xpert®), IGRA,
complemented by skin test and chest X-ray

Prevention: Avoiding airborne M. tuberculosis; BCG
vaccine in other countries

Treatment: Multiple-drug regimen, which may include
pretomanid, bedaquiline; and linezolid; in Serious Threat category in CDC Antibiotic Resistance Report

Community-acquired pneumonia (rhinovirus)

Causative organism: Rhinoviruses

Mode of Transmission: Droplet contact or endogenous
transfer

Virulence factors: N/A

Culture/Diagnosis: Failure to find bacteria or fungi

Prevention: Hygiene

Treatment: None

Community-acquired pneumonia (Streptococcus)

Causative organism: Streptococcus pneumoniae

Mode of Transmission: Droplet contact or endogenous
transfer

Virulence factors: Capsule

Culture/Diagnosis: Gram stain often diagnostic, alpha-hemolytic on blood agar

Prevention: PCV-13 or PPSV23 vaccine

Treatment: Doxycycline, ceftriaxone, with or without vancomycin; much resistance

Community-acquired pneumonia (Mycoplasma)

Causative organism: Mycoplasma pneumoniae

Mode of Transmission: Droplet contact

Virulence factors: Adhesins

Culture/Diagnosis: Rule out other etiologic agents; serology; PCR

Prevention: No vaccine, no permanent immunity

Treatment: Erythromycin

Community-acquired pneumonia (Legionella)

Causative organism: Legionella species

Mode of Transmission: Vehicle (water droplets)

Virulence factors: N/A

Culture/Diagnosis: Urine antigen test; culture requires selective charcoal yeast extract agar

Prevention: N/A

Treatment: Fluoroquinolone, azithromycin, clarithromycin

Community-acquired pneumonia (Histoplasma)

Causative organism: Histoplasma capsulatum

Mode of Transmission: Vehicle (inhalation of fungal
spores in contaminated soil)

Virulence factors: Survival in phagocytes

Culture/Diagnosis: Rapid antigen tests, microscopy

Prevention: Avoid soil contaminated with
bird and bat droppings

Treatment: Itraconazole

Community-acquired pneumonia (Pneumocystis)

Causative organism: Pneumocystis jirovecii

Mode of Transmission: Vehicle (inhalation of fungal spores)

Virulence factors: N/A

Culture/Diagnosis: Microscopy

Prevention: Antibiotics given to AIDS patients to prevent this

Treatment: Trimethoprim/sulfamethoxazole

Health-care associated pneumonia

Causative organism: Gram-negative and gram-positive bacteria from upper respiratory tract or stomach; environmental contamination of ventilator

Mode of Transmission: Endogenous (aspiration)

Virulence factors: N/A

Culture/Diagnosis: Culture of lung fluids

Prevention: Elevating patient’s head, preoperative education, care of respiratory equipment

Treatment: Varies by etiology

Hantavirus Pulmonary Syndrome Disease

Causative organism: Hantavirus

Mode of Transmission: Vehicle—airborne virus emitted from rodents

Virulence factors: Ability to induce inflammatory response

Culture/Diagnosis: Serology (IgM), PCR identification of antigen in tissue

Prevention: Avoid mouse habitats and droppings

Treatment: Supportive