In the post-mortem differential diagnosis of pulmonary tuberculosis in monkeys attention has been directed occasionally to mites infecting the lungs and causing lesions which grossly resemble tubercles. The infrequency of reports of pulmonary acariasis has prompted the publication of these observations, particularly as in some instances the lesions of true tubercle and acarid nodules were coexistent in the same lungs and could thus be compared.
The history of the animals follows: In the early spring of 1926 two cages containing 45 monkeys (Macacus rhesus) were received at Trudeau, New York, very soon after their arrival in New York City from Calcutta. All were in poor condition and suffering from diarrhea but none showed symptoms of pulmonary disease and no monkey reacted to a diagnostic subcutaneous injection of old tuberculin at the time of arrival. During their first two months in Trudeau 20 monkeys died, all of which at autopsy showed entero-colitis and intestinal oesophagostomum infection.