Gram-positive infections in granulocytopenic patients: an important issue?

Gram-positive pathogens have become a common cause of bacteraemia in granulocytopenic cancer patients. This has been partially attributed to the use of central intravenous devices such as Hickman catheters; mucositis secondary to intensive antineoplastic chemotherapy or herpes infections may also be the source, especially for streptococci, whereas the skin is most probably the source for Staphylococcus epidermidis. Antimicrobial prophylaxis recommended mainly with the aim of reducing the incidence of Gram-negative bacillary infections may also play a significant role. The rate of response of documented infections caused by Gram-positive cocci to 'standard' empirical therapy (which has been mainly directed against Gram-negative bacilli) has been unsatisfactory although the lethality reported has been low. These results raise an important question, whether or not a specific anti-Gram-positive antibiotic such as vancomycin, should be added to the empirical regimen. A recent study suggested that empirical vancomycin provided no benefit since the mortality due to Gram-positive infections was low and a favourable outcome was obtained by adding a specific antibiotic after bacteriological documentation. However, others have shown that empirical use of vancomycin was associated with a more rapid resolution of fever. Vancomycin has been associated with an excess rate of side-effects and is difficult to administer. Another important question is whether or not antimicrobial prophylaxis for gut decontamination should include anti-Gram-positive cover. Recent studies have confirmed that Gram-negative bacillary bacteraemia may be prevented by oral gut decontamination but not bacteraemia due to Gram-positive bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)