Pulmonary Disease From Nontuberculous Mycobacteria in Patients With Human Immunodeficiency Virus: Mycobacterium kansasii
Mycobacterium kansasii is antigenically and clinically more closely related to M tuberculosis than many of the other NTM species. Although this organism may be cultured from environmental water sources, it is less likely to be recovered from nonhuman sources and is seldom a contaminant when cultured from biologic specimens. In immunocompetent hosts, disease is most common among those with underlying lung abnormalities; chronic pulmonary infection closely resembles tuberculosis.
In patients with HIV infection, two forms of M kansasii infection have been described: disseminated infection and isolated pulmonary infection Link canadian pharmacy levitra. A review of experience at Parkland Memorial Hospital in Dallas over an 8-year period identified nine M kansasii infections in more than 1,100 HIV-positive patients (compared with 160 cases of dMAC and 50 of MTb). Five of these patients had only pulmonary disease; four had disseminated infection, including two whose primary clinical manifestation was pulmonary. One patient had a reported history of prior endobronchial M kansasii infection. The radiographic findings were heterogeneous, including upper lobe infiltrates, bibasilar nodular infiltrates, diffuse interstitial infiltrates, and hilar mass.
Valainis et al. conducted a review of M kansasii isolates over a 60-month period (1983 to 1988) from two referral centers in New Orleans. Two hundred five isolates from 72 patients were identified; 23 of the patients (31.9 percent) were HIV-seropositive. Symptoms present at the time of isolation of M kansasii included cough (79 percent), weight loss (72 percent), fever (68 percent), and dyspnea (53 percent). Fourteen patients, however, had documented Pneumocystis pneumonia concurrently, and in only 5 could M kansasii be repeatedly cultured. Of interest, 40 percent of isolates from HIV-infected patients were resistant to isoniazid at 4 Mg/ml.
Levine and Chaisson described 19 patients with HIV infection and M kansasii infection from Johns Hopkins Hospital: 14 with exclusively pulmonary disease, 3 with pulmonary and extrapulmonary infection, and 2 with exclusively extrapulmonary infection. All patients had advanced HIV disease with CD4+ lymphocyte counts of <200/mm (median =66) and six had PCP at the time of the initial diagnosis of M kansasii infection. Patients presented with subacute to chronic symptoms (median duration, 4 weeks) that included fever, cough, dyspnea, night sweats, pleuritic pain, and hemoptysis. Nine patients had diffuse infiltrates, and eight had focal upper lobe disease; thin-walled cavities were seen in nine. Treatment was successful in all patients (ten) who were treated with antituberculous agents.
Category: Respiratory Symptoms
Tags: AIDS, atypical Mycobacterium infections, HIV infection, Mycobacterium avium-intracellulare infection