A look-back investigation of patients of an HIV-infected physician. Public health implications.

BACKGROUND: Transmission of the human immunodeficiency virus (HIV) to five patients receiving care from an HIV-infected dentist in Florida has recently been reported. Current data indicate that the risk of HIV transmission from health care workers to patients is low. Despite this low risk, programs to notify patients of past exposure to an HIV-infected health care worker are being conducted with increasing frequency. METHODS: We recently conducted an investigation of all the patients cared for by an HIV-infected family physician during a period when he had severe dermatitis caused by Mycobacterium marinum on his hands and forearms. After reviewing the patients' records, we notified 336 patients who had undergone one or more procedures (digital examination of a body cavity or vaginal delivery) placing them at potentially increased risk of HIV infection. The patients were offered tests for HIV infection and counseling. RESULTS: Of the 336 patients, 325 (97 percent) had negative tests for HIV antibody, 3 (1 percent) refused testing, 1 (less than 1 percent) died of a cause unrelated to HIV infection before notification, and the HIV-antibody status of 7 (2 percent) remained unknown. The direct and indirect public health costs of this investigation were approximately $130,000. CONCLUSIONS: The results of this investigation raise important questions about the risk of HIV transmission from health care workers to patients and the usefulness of HIV look-back programs, particularly in the light of recently published recommendations from the Centers for Disease Control. We propose that before a look-back investigation is undertaken, there should be a clearly identifiable risk of transmission of the infection, substantially higher than the risk requiring limitation of an HIV-infected health care worker's practice prospectively.

[Experimental reproduction of lactic acidosis in the pony]. / Reproduction expérimentale de l'acidose lactique chez le poney.

One pony has been subjected to the intravenous injections of L-lactic acid. Two other ponies have been trained to intracaecal administration of L-lactic acid or sucrose. The obtained results show that: Intravenous injection of lactic acid increases the concentration of histamin and lactic acid, decreases the level of magnesium and reduces the pressure of carbon dioxide in the blood (the control animals and the treated animals) without the clinical symptoms of lactic acidosis. Intracaecal administration of lactic acid induces a high liberation of histamin in the caecum (the control animals and the treated animals), however, the level of histamin in the blood is not modified. Intracaecal administration of sucrose decreases pH and increases the concentration of lactic acid in the caecum, although, in this case, the accumulation of histamin in the caecum appears only in the non-fasting ponies, the starved animals, and the fed animals, which suggests the necessity of food's proteins for histamin synthesis.