(Adapted from MMWR, September 29, 1995) On June 27, 1995, a crew of five workers began partial demolition of an abandoned city hall building in Belfry, Kentucky. One truck driver who hauled the debris to the dump, four workers who helped the driver haul and dump the debris, and two people who had washed the building assisted them. At the time of demolition, a colony of bats had been observed in the vicinity of the building, and an approximately 2-foot deep pile of debris covered with bat guano had accumulated in the building. During the demolition, none of the workers wore personal protective equipment (i.e., respirators, eye protection, gloves, or protective clothing). Within 3 weeks, six of these workers required treatment for acute respiratory illnesses, and three had been hospitalized. Their symptoms included chills, fever, cough, and headache. Several had substernal discomfort, and several had painful skin lesions. Rales were heard on auscultation. Because the men had all worked together, a common source of infection was suspected, probably an environmental source.
Question 1 - Single Best Answer
Which of the following diseases have an environmental source and are most likely to be responsible for these menŐs illnesses?
A) asbestosis
B) pneumococcal pneumonia or staphylococcal pneumonia
C) LegionnaireŐs disease or tuberculosis
D) Botulism or tetanus
E) Histoplasmosis or Blastomycosis
F) Cryptococcois or Coccidioidomycocis
G) Histoplasmosis or LegionnaireŐs disease.
Question 2 - Single Best Answer
X-rays were done on the symptomatic workers and showed interstitial infiltrates and hilar adenopathy. Which of the following statements is correct?
A) This proves that it is histoplasmosis
B) This proves that it is coccidioidomycocis
C) This proves that it is blastomycosis
D) This proves that it is LegionnaireŐs disease
E) This shows that we need to enlarge our differential diagnosis.
F) None of the above
Question 3 - Single Best Answer
Why would you favor a diagnosis of histoplasmosis rather than blastomycosis?
A) Blastomycosis usualy presents as an encephalitis
B) Blastomycosis is not endemic in the United States
C) Blastomycosis is not endemic in Kentucky
D) Blastomycosis is always asymptomatic
E) None of the above
Question 4 - Single Best Answer
Why would you favor a diagnosis of histoplasmosis rather than coccidioidomycocis?
A) Coccidioidomycocis usually presents as an encephalitis
B) Coccidioidomycocis is not endemic in the United States
C) Coccidioidomycocis is not endemic in Kentucky
D) Coccidioidomycocis is always asymptomatic
E) None of the above
Question 5 - Single Best Answer
What do histoplasmosis, coccidioidomycocis, and blastomycosis have in common?
A) They are all caused by molds
B) They are all acquired by inhalation
C) They all cause a preponderance of inapparent infections
D) They are all caused by dimorphic fungi
E) All of the above
Question 6 - Single Best Answer
How could an acute infection of histoplasmosis be proven?
A) Skin test for reactivity to histoplasmin
B) Growth of the organism from sputum
C) Acid fast bacterium seen in the sputum
D) Giemsa stain of lung biopsy
E) Complement fixation titer of 1:32 or higher
F) Either Giemsa stain of lung biopsy or complement fixation titer of 1:32 or higher
Lung biopsies of the three hospitalized patients were obtained. Giemsa stained tissue from the lung biopsy of one of the patients suggested the presence of Histoplasma capsulatum. All of these individuals developed high complement fixation titers for antibodies to the organism. Two other workers also had high c.f. titers. The 6th individual had milder respiratory symptoms and was not tested. The workers who were not sick enough to see a doctor, as well as the 6th individual who had not been tested were later tested for antibodies to Histoplasma capsulatum. All but one were positive. The five sickest individuals were the ones that had done the actual demolition work.
Question 7 - Single Best Answer
What is the most likely reason that these were the sickest?
A) They were all on steroids
B) They all had AIDS
C) They all had the most exposure
D) They were the only ones that hadnŐt been exposed to the organism before.
Question 8 - Single Best Answer
Is the fact that bats had inhabited the building significant?
A) Yes
B) No
Question 9 - Single Best Answer
In what other diseases is exposure to birds a factor?
A) Saint Louis Encephalitis Virus (SLEV) and Chlamydia trachomatis
B) Eastern Equine Encephalitis Virus (EEEV) and Poliovirus
C) Cryptococcus and Chlamydia psittaci
D) Coccidioidomycosis and Blastomycosis
Question 10 - Single Best Answer
Histoplasmosis is also called spelunkerŐs disease. This is because
A) most people canŐt spell it right
B) it is also transmitted in Trail Mix
C) bats are often found in caves
D) it is also transmitted by river water
Question 11 - Single Best Answer
What other disease might be called spelunkerŐs disease?
A) Rocky Mountain Spotted Fever
B) Lyme Disease
C) Rabies
D) Coccidioidomycosis
E) Cryptococcosis
All of the symptomatic individuals recovered uneventfully but two. One of them developed shortness of breath and progressive swelling of the lower extremities and the face. The other one succumbed to an overwhelming infection that eventually spread to every organ of his body.
Question 12 - Single Best Answer
The latter patient likely had
A) chronic obstructive pulmonary disease
B) AddisonŐs disease
C) the highest exposure to the organism
D) AIDS
Followup x-rays were done on all the individuals who survived. The x-ray of the one that had progressive shortness of breath showed a mass in his mediastinum, which compressed several bronchi. A venogram showed compression of the superior and inferior vena cava as well.
Question 13 - Single Best Answer
What would you expect to see in the x-rays of the individuals that recovered?
A) lung abscesses
B) calcified nodules in the periphery of the lungs
C) increased interstitial infiltrates
D) healed lesions in the upper lobes of the lung
E) a completely normal x-ray
Question 14 - Single Best Answer
The individual that had progressive shortness of breath and an x-ray that showed a mass in his mediastinum had what histoplasmosis-related problem?
A) lung cancer
B) lung abscess
C) pneumococcal pneumonia
D) mediastinal fibrosis
E) Aspergillosis
Question 15 - Single Best Answer
Who should be treated for histoplasmosis?
A) Noone
B) Everyone with respiratory symptoms
C) Individuals with disseminated histoplasmosis
D) Only immunocompetent patients, immnodeficient patients will have a severe immunological response after treatment.
Question 16 - Single Best Answer
What is the best treatment for those who require it?
A) penicillin
B) amphotericin B
C) fluconazole
D) metronidazole
E) isoniazid
Question 17 - Single Best Answer
What is the mechanism of action of amphotericin B?
A) it interacts with sterols in the cell membrane
B) it is deaminated to flourouracil and incorporated into RNA
C) it inhibits sterol biosynthesis
D) it inhibits microtubular function and acts as a mitotic poison