Inhalation fever, bioaerosols

CASES/YEAR
5,000 (US); 100,000 (Global)
CATEGORY
Immune-Related
AGENT TYPE
Other
OTHER NAMES
Organic dust toxic syndrome (ODTS); Mill fever; Grain fever; Humidifier fever; Pontiac fever;
ACUITY
Acute-Moderate
INCUBATION
4 to 8 hours; up to 3 days for Pontiac fever;
INITIAL SYMPTOMS
Flu-like illness with respiratory symptoms;
PRECAUTIONS
COMMENTS
Inhalation fever from bioaerosols is caused by heavy exposure to moldy organic dust (hay, silage, compost, wood chips, and grain) or to mists from air conditioning and humidifier systems contaminated with mold or bacteria. Patients often have eye and nasal irritation and then develop a flu-like illness with cough. Patients may have leukocytosis, but the chest x-ray is normal. Inhalation fever resolves without treatment within one to three days. Mill fever occurs in cotton mill workers after heavy exposure to dusts of cotton, flax, soft hemp, or kapok. Grain fever is caused by grain dust contaminated with bacterial endotoxins, storage mites, and fungi. Humidifier fever is associated with stagnant water and forced-air ventilation systems. Pontiac fever occurs after exposure to bioaerosols of the bacterium, Legionella pneumophilia. In contrast to Legionella infection (Legionnaire disease), Pontiac fever has a high attack rate (95%-100%) and a short incubation period (5-66 hours). [Rom, p. 408] "Infiltrates on the chest radiograph can occur with neutrophilia and hypoxemia that can mimic acute pneumonia or acute hypersensitivity pneumonitis." Workers usually have complete resolution of symptoms within 24-48 hours. Symptoms become milder with daily repeated exposures. [Cecil, p. 576] See "Inhalation fever, fumes." See "Hypersensitivity pneumonitis."
DIAGNOSTIC
Clinical
SCOPE
Global
SIGNS & SYMPTOMS
  • >arthralgia
  • >fatigue, weakness
  • >fever
  • >myalgia
  • E rhinitis
  • G abdominal pain
  • G nausea, vomiting
  • H leukocytosis
  • N headache
  • R cough
  • R dyspnea
  • X lung infiltrates
  • *pneumonitis
ANTIMICROBIC

No

VACCINE

No

ENTRY
Inhalation
SOURCE
RESERVOIR
RISK FACTORS
  • Inhale bioaerosols indoors
  • Inhale bioaerosols of moldy compost
  • Inhale livestock confinement building dust
  • Inhale moldy hay, silage, or grain
  • Inhale moldy wood dust
TREATMENT
No specific therapy;
DRUG LINK
REFERENCES FOR CASES/YEAR
1. (US) Of the 3522 cases detected in 2009, 95.5% were Legionnaire's disease (LD) and 0.05% were Pontiac fever; [MMWR 2011, p. 1083-6] LD: 53,000 cases/year; [See "Legionellosis."] Guesstimate: 0.05 X 53,000 = 2650 and assume about as many from other causes = total of 5000;
2. (Global) Estimate global rate at 20 X US rate;