[Incidence and etiology of viremia in 2,619 patients]

Virus investigation, specially cytomegalovirus (CMV), in blood has increased such that the capacity of hospitalary laboratories is threatened with collapse. The causal agents of viremia are analyzed being correlated with the clinical symptoms and underlying disease to establish the selection criteria of patients for virologic study.

Two thousand six hundred nineteen patients suspected of having viral infection, fundamentally by CMV were studied over 6 years by 4,394 blood samples. Of these patients 1,646 were immunosuppressed, 824 were considered immunocompetent and this data was unknown in 149 patients. The leukocytes were separated using standardized techniques being seeded in cell cultures (human embryo lung fibroblasts).

Three hundred forty-seven specimens corresponding to 242 patients were positive with isolation of the following pathogens: 327 strains of CMV, 4 enterovirus, 2 adenovirus, 1 herpes simplex virus, 1 varicella-zoster, another 5 unidentified cytopathic agents, 6 strains of toxoplasma and 1 Cryptococcus. With regard to the base disease, 302 positive samples to CMV pertained to 204 immunosuppressed patients: 103 (13.6% positives among the cases studied) AIDS or AIDS-related complex, 54 (21.3%) kidney transplant patients, 31 (24.8%) liver transplant patients, 2 (1.5%) lung transplant patients, and 2 (1.5%) bone marrow transplant patients. A non CMV microorganism was isolated in 13 samples from 12 immunosuppressed patients. Only 24 (2.5% of those studied) immunocompetent or with unknown immunity status had viremia by CMV, being detected in 25 samples. Non CMV cytopathic agents were isolated in another 7 samples from 6 patients.

Analysis of blood cultures allows the isolation of cytomegalovirus and occasionally other unsuspected agents such as toxoplasma. This investigation is indicated in immunosuppressed patients but not in immunocompetent patients who present a febrile syndrome with no clinical suspicion of cytomegalovirus infection.