This is a fatal case of Pneumocystis pneumonia (PCP).
Back when this case showed up in our lab, in 1984, PCP was beginning to become common killer in the HIV/AIDS community. Prior to HIV/AIDS, PCP was rarely seen. Much like other infectious diseases and immunologically related diseases such as Cryptococcal meningitis and Kaposi’s sarcoma, there was a significant uptick related to the HIV/AIDS epidemic. Back in those days PCP was thought to be a protozoan and thus in many parasitic text books it has retained its presence in their pages. Today it is classified as a fungus.
The fungus is ubiquitous in nature. Normal immune systems keep the fungus in check. It is when the immune system becomes compromised as in an HIV/AIDS patient that the organism can establish itself in the host and cause disease. Up to 40% of the cases of PCP are in the HIV/ADIS population. The rest of the cases are distributed in various other disease states that compromise the immune system. Diseases/conditions such as COPD, cancers, immunosuppressive drugs given to reduce the incidence of organ transplant rejection, and any kind of inflammatory autoimmune disease.
The symptoms of PCP usually will develop within a span of several days after being exposed. But there can be some cases where it isn’t for weeks until the symptoms appear. The symptoms include fevers; chest pain; chills; dyspnea; coughing; fatigue.
Most of us are exposed to this fungus and our intact immune system will clear it. 20% of the population may carry it at a time. This population can be a source of spread via droplets to susceptible individuals. Though as previously stated the fungus is ubiquitous in nature and therefore is most likely acquired through environmental exposure.
Diagnosis is usually made by collecting sputum or a bronchioalveolar lavage specimen. The bronchioalveolar lavage specimen is a much more reliable specimen for the detection of the fungus. In highly suspected cases where the above specimens are not acquired as needed then there may be the need to perform a lung tissue biopsy but only as a last resort. Especially when there are highly sensitive PCR tests available. These are not routinely available however and direct fluorescent antibody staining or silver stains are employed instead.
Lung radiographic studies can provide a strong suspicion of PCP given the history of the patient. The most common finding in high resolution CTs is the appearance of a diffuse ground-glass opacity or GGO. This finding is thought to be due to the accumulation of intralveolar fibrin, debris and organisms.
The infection must be treated. PCP can cause death in the vulnerable patient. Indeed, during the HIV/AIDS epidemic the PCP fatality rate was especially high. Today with the advent of fantastic antiretroviral drugs to treat HIV/AIDS, the incidence of many of the diseases such as PCP have dramatically reduced the fatal outcomes of the past. These antiretroviral drugs are critical to maintaining the CD4 cell counts elevated and the viral loads low to non detectable. Effectively keeping the patient relatively immunocompetent. In cases of PCP the drug of choice is trimethoprim/sulfamethoxazole or (TMP/SMX). The drug is most popularly known by its trade names, Bactrim, Septra, and Cotrim. Treatment consists of oral or venous administration of the antibiotic for a period of about 3 weeks. Treatment options are available for patients that are hypersensitive to TMP/SMX. Long term preventative medicine can be beneficial for some HIV/AIDS patients more at risk to PCP due to resistant or refractory infections with the virus.
This case was especially difficult for most of us in the lab who knew the patient personally and professionally. Not one of us had any hint of him being HIV positive. At that time the overwhelming stigma of the disease would have been overwhelming for him to bear. It was early in the HIV/AIDS epidemic. The stigmas had already been deeply perpetrated. The questions to answer would have been too personal in a culture of misunderstanding. In the end he refused to have anyone visit him. Better to be alone than be judged. And that bothered me. Because no one deserves to be alone as they draw their last breaths.