Which disease is transmitted to humans primarily via the bite of the Oriental rat flea and can occur in a pneumonic form, posing serious risk if inhaled?

• A. Plague
• B. Murine typhus fever
• C. Rickettsial pox
• D. Dermatitis

Answer: (A)

Plague is the illness described. It’s caused by Yersinia pestis and is classically spread to people by the bite of the Oriental rat flea, Xenopsylla cheopis. Plague can present in several forms, including bubonic (from a flea bite) and pneumonic, the latter arising when the infection reaches the lungs. Pneumonic plague is especially dangerous because it can be transmitted via inhaled respiratory droplets, posing a serious risk to anyone nearby if inhalation occurs.

The other options don’t fit as well: murine typhus fever is also flea-borne but not known for a pneumonic form; rickettsial pox is transmitted by mites, not fleas; dermatitis is not a disease transmitted by fleas.