Detection of HIV-1 infection in blood donors during the immunological window period using the nucleic acid-amplification technology.

Individual nucleic acid-amplification testing (NAT) was recently recommended by Brazilian legislation and has been implemented at some blood banks in the city of São Paulo, Brazil, in an attempt to reduce the transfusion transmission of human immunodeficiency virus (HIV) and hepatitis C viruses. This screening test can identify donations made during the immunological window period before seroconversion. The impact of this technology in our blood donors and transfusion routine was studied. In all, 47 866 donations were tested from March 2004 until November 2005, according to Brazilian legislation, using two approved enzyme immunoassays for HIV antibodies and individual NAT. Supplemental tests included Western blot, p24 antigen detection and quantitative PCR-HIV-1. Among the donors screened, two (one first-time and one repeat donor) were non-reactive in enzyme immunoassays, with negative confirmatory p24 antigen and Western blot, but positive for HIV-1 NAT. Although serological analysis for HIV is a primary tool for diagnostic testing, the addition of NAT allowed for identification and prevention of component transfusion from two HIV-positive blood donations during an 18-month period. The screening of donors reduced the immunological window period, permitting the identification of very early stage HIV infections. In addition, this report also emphasized the fact that the risk of HIV transmission is not limited to the first-time donors.

Incidence of and risk factors for nosocomial pneumonia in patients with tetanus.

From June 1998 through July 2000, 28 patients with tetanus admitted to the Intensive Care Unit for Tetanus and Infectious Diseases at the Hospital das Clínicas of University of Medicine at São Paulo, Brazil, were evaluated to establish what the incidence of nosocomial pneumonia was and what their risk factors were. The degree of severity of tetanus was assessed in all patients by means of APACHE II scores. The mortality rate was 3.6%. There were 63 hospital infections in 20 patients; among these, there were 10 cases of nosocomial pneumonia in 8 patients. Nosocomial pneumonia was associated in univariate analysis with the degree of severity of tetanus, dysautonomy, use of neuromuscular blockers, use of higher doses of diazepam, and lower arterial oxygen and oxygen fractions. In the multiple logistical regression, significance was found for dysautonomy (relative risk, 31.67; 95% confidence interval, 2.68-373.74; P=.006). Dysautonomy was an independent risk factor for pneumonia in patients with tetanus.

Risk of health care professionals acquiring HIV infection in Latin America.

This study describes the professional risk of acquiring HIV infection while caring for AIDS patients at a teaching hospital in Brazil. Since 1985 we have tested health care professionals (HCP) for HIV-1 antibody after accidents with blood and body fluids from AIDS patients. The blood samples were tested twice using an ELISA FDA approved test and, if positive, we performed Western blot. Two hundred and forty seven health care professionals reported 338 accidents (50% were percutaneous and 22% were mucous membrane exposures to blood). A further 404 HCPs reported no occupational exposure but wanted to be tested. From 247 HCPs with at least one accident, we analyzed 115 with more than 6 months of follow up. None were HIV antibody positive. Nobody received zidovudine as a prophylaxis. Of the 404 HCPs with no accident, 6 (1.5%) were positive and had confirmed risk factors for HIV. Our results support other studies that report a low occupational risk (about 0.4%) of acquiring HIV infection.

Aztreonam in the treatment of bacterial meningitis.

The monobactam aztreonam was used to treat 22 young patients with meningitis caused by gram-negative bacilli. Haemophilus influenzae was isolated from the CSF of 21 patients and Salmonella heidelberg from the CSF of 1. Dosages ranged from 100 to 200 mg/kg/day in 4 doses at 6-hour intervals. Minimal inhibitory concentrations were determined by the broth dilution method for all isolated strains, and values ranged from 0.05 to 2.0 micrograms/ml. Blood and CSF drug levels were determined by a microbiologic plate diffusion method, and mean values for CSF and blood were 1.4 and 14.9 micrograms/ml, respectively. The outcome was good in 21 patients; 1 patient died. Complications were mild; subdural effusion occurred in 6 cases and was managed clinically; asymptomatic hydrocephalus was seen in 4; seizure during the acute phase occurred in 6 cases; hypoacusis was noted in 2, and motor impairment was detected at the follow-up in 1 case. Aztreonam achieved good blood and CSF penetration and performed well in the treatment of 20 cases of H. influenzae meningitis and in the one case of S. heidelberg meningitis.