Penicilliosis
Penicilliosis is a fungal infection caused by the dimorphic fungus *Penicillium marneffei*, primarily affecting individuals with compromised immune systems, particularly those with human immunodeficiency virus (HIV) infection. This infection is most commonly found in endemic regions such as Southeast Asia, Guangxi Province of China, Hong Kong, and Taiwan, and its incidence correlates with HIV rates in these areas. Symptoms often include fever, weight loss, skin lesions, lymphadenopathy, and hepatomegaly, with pulmonary symptoms occurring in about half of the cases. Diagnosis typically involves identifying the fungus from clinical specimens or biopsies, while elevated liver enzymes can also aid in diagnosis. Effective treatment includes antifungal medications like ketoconazole and amphotericin B, with a high response rate if treated early. However, without treatment, the prognosis is poor due to potential liver failure and a high risk of relapse, which can occur in about 50% of cases in the absence of ongoing prophylaxis. Preventive measures, including the use of itraconazole, have been shown to significantly reduce the incidence of penicilliosis in at-risk populations.
Penicilliosis
- ANATOMY OR SYSTEM AFFECTED: Blood, lungs, lymphatic system, respiratory system, skin
- ALSO KNOWN AS: Penicillosis
Definition
Penicilliosis is the third most common opportunistic infection in persons with human immunodeficiency virus (HIV) infection, namely in the areas of the world in which penicilliosis is endemic. The incidence of penicilliosis, a fungal infection, in endemic areas parallels the incidence of HIV infection.
Causes
Penicilliosis is caused by the dimorphic fungus Penicillium marneffei, which is either spherical or oval and about 3 to 6 microns long. It is endemic to Southeast Asia, the Guangxi Province of China, Hong Kong, and Taiwan. P. marneffei appears in tissue as a unicellular organism that reproduces by planate division. It is a mold at room temperature and converts to the yeast form if incubated at 98.6° Fahrenheit (37° Celsius). This dimorphism is not found in other members of the genus Penicillium.
Risk Factors
Compromised immunity and acquired immunodeficiency syndrome (AIDS) render a person susceptible to penicilliosis. Recent exposure to a potential environmental reservoir of organisms is the predominant risk factor. Cases of penicilliosis occasionally are seen outside endemic areas, but most of these cases involve the infected person having a history of travel to an endemic area. The fungus has been isolated from four species of bamboo rats and from soil. Infection seems to be more frequent in the rainy season.
Symptoms
The most common presentation of this disease is disseminated infection, manifested by fever and weight loss (which occur in more than three-fourths of cases), anemia, skin lesions (in approximately two-thirds of cases), generalized lymphadenopathy, and hepatomegaly with or without splenomegaly. Lesions usually appear on the face, trunk, and extremities as papules with central necrotic umbilication; folliculitis and lesions that look like acne also may occur.
Pulmonary symptoms occur in about 50 percent of cases. Chest radiographic abnormalities typically manifest as diffuse reticulonodular infiltrates, though 50 percent of cases have normal chest radiographs. Persons affected by penicilliosis usually have AIDS and low CD4 lymphocyte counts.
Screening and Diagnosis
Diagnosis is usually made by identification of the fungi from clinical specimens. Biopsies of skin lesions, lymph nodes, and bone marrow demonstrate the presence of organisms on histopathology. The elevation of liver enzymes in the blood helps to establish a diagnosis. A specific polymerase chain reaction assay is under evaluation and could be useful as an alternative test for rapid diagnosis.
Treatment and Therapy
P. marneffei usually demonstrates in vitro susceptibility to multiple antifungal agents, including ketoconazole, itraconazole, miconazole, flucytosine, and amphotericin B. The response to antifungal treatment is good if the treatment is started early; without treatment, the prognosis is poor. Death occurs if the liver fails (that is, it can fail if the fungus releases toxins in the bloodstream). Response rates of up to 97 percent have been reported with amphotericin B therapy for the first two weeks, followed by ten weeks of itraconazole.
After the initial treatment, the infected person may need to take an antifungal drug as a secondary prophylaxis for life. Relapse occurs in the absence of prophylaxis in approximately 50 percent of infected persons.
Prevention and Outcomes
Primary prophylaxis can prevent the occurrence of penicilliosis. A randomized, placebo-controlled study from Chiang Mai University suggests that primary prophylaxis with itraconazole (200 milligrams daily) can prevent penicilliosis in persons with AIDS and in those with CD4 counts less than 200 cells per microliter. Of 129 persons enrolled in the study, penicilliosis occurred in only one case in the itraconazole group compared with eleven cases in the placebo group, a statistically significant difference. In addition, there were fewer cases of cryptococcosis and candidiasis in the itraconazole group, but no survival difference between groups was detected.
Bibliography
Dismukes, William E., Peter G. Pappas, and Jack D.Sobel, eds. Clinical Mycology. New York: Oxford University Press, 2003.
Galanda, Claudia D., ed. AIDS-Related Opportunistic Infections. New York: Nova Biomedical Books, 2009.
St. Georgiev, Vassil. Opportunistic Infections: Treatment and Prophylaxis. Totowa, N.J.: Humana Press, 2003.
"Talaromycosis (Penicilliosis) Basics." Centers for Disease Control and Prevention (CDC), 15 May 2024, ww.cdc.gov/talaromycosis/about/index.html. Accessed 4 Feb. 2025.