Infecção respiratória aguda grave no paciente HIV positivoaspectos clínicos e epidemiológicos

Pneumonia is the third global cause of death and among the HIV population is the leading one. Introduction of PCR technique enables viral detection in up to one third of the cases. WHO points at the need to strenghten Severe Acute Respiratory Infection surveillance, which has recently been redefined as: fever, and cough, and ten days of onset of symptons and need for hospitalization. On the other hand, brazilian Ministry of Health (MH) promotes surveillance on Severe Acute Respiratory Syndrome (SARS), which primaraly involves the need to fill influenza-like illness case definition known as: ―suddenly onset‖ of fever and cough or odinophagia and one of the following symptons headache or myalgia or arthralgia. In order to explore the clinical and epidemiological aspects of respiratory infection in the HIV population, a prospective observational study was conducted at INI-IPEC. For each HIV positive patient hospitalized with fever and cough and up to 30 days of symptons onset, blood cultures were taken to explore bacterial, fungus and Mycobateria spp infection, sputum for Mycobacterium spp, urine for Streptococcus pneumonia and Legionella pneumophila-1 antigen detection and nasopharyngeal swabs for a panel of virus detection through rt-PCR. Clinical data were extracted from chart through a standardized questionnaire until death or hospital discharge. Among the 49 patients included, the median age was 38 years old and the majority of them presented at HIV associated late-stage disease, despite 78% being HAART exposed. The median time of symptons onset and hospital entry were ten days, 73% of them exhibited a multilobar X-Ray infiltrate and 80% scored zero or one point at CRB65 score. Despite the low scoring, 67% needed non-invasive ventilation support and/or oxygen therapy in the first 72 hours of admission, 31% underwent mechanical ventilation (MV) and overall mortality found were 18.3%. Factors associated with mortality were CD4 nadir cell count, microbiological identification, vasoactive drugs, MV and hospital-acquired infection. Scoring two-four points at CRB65 could not predict death but CRB65 + pulse oxymetria below 90% was significantltely associated with mortality. The clinical and epidemiologycal aspects of the 27 patients with SARI were similar to those of the whole population included and the microbiological agents identified, in descending order, were: nine virus, Mycobaterial tuberculosis (TB) was the main agent identified in six patients and Streptococcus pneumoniae and Pneumocystis jiroveccii each one in four patients. The two Cryptococcus neoformans and the only case of Legionella pneumphila-1 were identified only in non-SARI patients. The expression ―suddenly onset‖ of symptons, for SARS definition in Brazil, did not apply to HIV/AIDS population in this study, due to late-HIV associated disease and the overlaping of other opportunistic diseases. If one consider ―10 days of symptons onset‖, 11 patients could be retrieved and 3 virus identified. Only one out three influenza cases were captured by both approaches. The other 2 influenza slipped surveillance due to 20 and 30 days of onset of symptons, respectively. The lack of a clear cut-off on the brazilian SARS case-definition may jeopardize the standardization of SARS surveillance in the HIV/AIDS population, which, in turn, precludes incidence comparison between region and countries that relies on the OMS criteria. The possibility of prolonged viral shedding in this population points at the need for adapting SARS and SARI influenza surveillance for HIV/AIDS patients. In places were TB is endemic, Mycobaterium tuberculosis should be persued as a cause of respiratory illness in hospitalized HIV/AIDS patients, despite less than ten days of fever and cough.