VIRULENT INFECTIONS CAUSED BY ALPHA-HEMOLYTIC STREPTOCOCCI IN CANCER-PATIENTS AND THEIR MANAGEMENT

Streptococci of the viridans group have long been considered to be min or pathogens, except in bacterial endocarditis. For some years, howeve r, these microorganisms have been the cause of serious bacteraemia in neutropenic patients receiving intensive chemotherapy. These infection s can lead to severe complications such as endocarditis, respiratory d istress syndromes or shock, and are associated with a mortality rate r anging from 6-30%. The principal risk factors for these infections are profound neutropenia, antibiotic prophylaxis with quinolones or cotri moxazole, large doses of cytosine arabinoside, a recent history of che motherapy, oropharyngeal mucositis and viridans streptococcal coloniza tion. Protective factors are the early administration of parenteral an tibiotics during periods of neutropenia, or the prophylactic administr ation of penicillin. Although the introduction of penicillin to prophy lactic antibiotic regimens has led to a decrease in the incidence of t hese infections, the emergence of strains resistant to beta-lactams is a worrying problem which could compromise this type of treatment.