Q&A: Causes of Occupational Pneumonia

Environmental and occupational issues present both diagnostic and preventive care opportunities in primary care practice, emergency medicine, pediatrics, and various medical specialties. Clinicians need to know how to take a good environmental/occupational history and should have a reasonable understanding of common environmentally related illnesses and injuries as well as basics of exposure assessment.

This article is for Medical Students & Professionals

This is a  Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find the Pneumonia article more useful, or one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.

In this article:
Occupational disease
MCQ exam: clinical scenario
MCQ exam: answer
MCQ exam: explanation

Occupational disease

An occupational disease is any chronic ailment that occurs as a result of work or occupational activity. It is an aspect of occupational safety and health. An occupational disease is typically identified when it is shown that it is more prevalent in a given body of workers than in the general population, or in other worker populations.

Environmental and work exposures can cause or aggravate a variety of common diseases such as asthma, carpal tunnel syndrome, dermatitis, hepatitis B, and cancer. In many cases, the work- or environment-related illnesses do not have unique clinical presentations: asthma caused by latex allergy does not differ from asthma precipitated by a cat allergy; median nerve entrapment related to acute trauma or repetitive motions has the same constellation of symptoms and signs as carpal tunnel syndrome due to pregnancy; headache due to carbon monoxide poisoning can be mistaken for severe tension headache or migraine. Symptoms related to hazardous exposures can appear as complaints involving any body system and mimicking ordinary medical diseases.

MCQ exam: clinical scenario

A pet shop owner develops a febrile illness characterized by pneumonia and systemic symptoms. Chlamydia is isolated from a clinical specimen.

The most likely diagnosis is:

a) Lyme disease
b) brucellosis
c) infective endocarditis
d) listeriosis
e) psittacosis

MCQ exam: answer

The correct answer is E.
Psittacosis is the most likely cause.

MCQ exam: explanation

Psittacosis is primarily an infectious disease of birds caused by the bacterium Chlamydia psittaci. Transmission from infected birds results in a relatively rare febrile illness characterized by pneumonia and systemic symptoms. A flu -like illness can also occur.

Almost any bird can harbor this bacterium in their excreta, tissues, feathers, and secretions, but parrots, parakeets, and budgerigars are the most common.

Psittacosis is considered an occupational disease of pet shop owners. Psittacosis is almost always transmitted to humans by the respiratory route. Average incubation is 7-14 days.

Reference(s)
1). UptoDate: Overview of occupational and environmental health. Available online: https://www.uptodate.com/contents/overview-of-occupational-and-environmental-health