Advances in antimicrobial therapy for respiratory tract infections.

Even at the turn of the millennium, respiratory infections exact a heavy toll on the American public. Pneumonia is the leading infectious disease cause of death, and influenza costs Medicare more than $1 billion each year. This article highlights some of the advances this past year in antimicrobial therapy for respiratory tract infections. Efforts are targeted at shortening the length of treatment and reducing costs for pneumonia. A promising new class of antivirals has been introduced for the treatment of influenza, and alternative medicine continues to receive more scientific scrutiny. Antimicrobials alone are not the answer, and preliminary work on immunomodulatory therapies may usher in a new era of multifaceted treatment approaches.

Clinical manifestations and implications of coinfection with Mycobacterium kansasii and human immunodeficiency virus type 1.

We conducted a retrospective study to further elucidate the clinical presentations and prognosis of disease due to Mycobacterium kansasii in patients infected with human immunodeficiency virus (HIV). Forty-nine HIV-infected patients first had M. kansasii isolated at a mean CD4 cell count of 62/mm3 and at a mean interval of 17 months after the diagnosis of AIDS. Seventeen of the 49 patients had disseminated disease caused by M. kansasii. Twenty-nine patients had a positive acid-fast smear of sputum, and 35 were known to be cigarette smokers. At the time of initial isolation of M. kansasii, 13 patients had other concurrent pulmonary isolates and 15 had another mycobacterial species concurrently isolated (the Mycobacterium avium complex in 13 instances). Patients who received antimycobacterial treatment survived longer than those who did not. Only one of the 49 patients was definitively determined to be colonized with M. kansasii without disease; therefore, it appears that pulmonary isolates of M. kansasii in HIV-infected patients are almost always associated with disease. The increase in rates of M. kansasii disease among HIV-infected patients has paralleled the rise of AIDS in Louisiana. So far, this state has recorded more coinfections with M. kansasii and HIV than any other.

Neurologic aspects of North American zoonoses.

Neurologic dysfunction is a frequent presentation or complication of zoonotic infections. The differential diagnosis is broad and will include nonzoonotic diseases as well. Patterns of neurologic findings, systemic signs of infection, and epidemiologic risk factors are useful in the approach to diagnosis and initial empiric treatment of the patient with suspected zoonotic infection. Associations between these patterns and specific organisms are emphasized by means of tables and algorithms.