Researchers Determine Frequency of Bloodstream Infections in Patients With Febrile Neutropenia

One in 5 patients with febrile neutropenia experience bloodstream infection, which often results in mortality and highlights the importance of awareness of prevalent pathogens and their susceptibility pattern for effective treatment of infection. Examining the frequency of bloodstream infection in these patients, researchers have found that staphylococcus aureus is most prevalent, followed by Klebsiella and E. coli.

Between February 21, 2016, and August 20, 2017, the researchers observed 200 patients over age 15 with severe neutropenia. Each patient had 4 to 5 ml of venous blood taken, which was sent to the laboratory within 20 minutes of collection, and antimicrobial sensitivity testing of all isolates were performed on diagnostic sensitivity test plates.

According to the researchers, Staphylococcus aureus was identified as round grape-like colonies under the microscope; Pseudomonas aeruginosa was identified as rod-shaped bacteria with unipolar motility; E. coli was identified as rod-shaped and 2 mm long and 0.5 μm in diameter; and Klebsiella pneumonae was identified as small rod-shaped structures inoculated in culture.

During the study period, 89 patients (44.5%) had low-grade fever and 111 (55.5%) had high-grade fever. The frequency of Staphylococcus aureus was 16%, E. coli was 14.5%, Pseudomonas aeruginosa was 8.5%, and Klebsiella pneumonae was 15.5%.

Staphylococcus aureus (19.2% vs 11.3%) was more common in men than in women, while Pseudomonas aeruginosa (10% vs 7.5%), E. coli (15% vs 14.2%), and Klebsiella pneumonae (17.5% vs 14.2%) were more common in women than in men.

“Thirty years ago most of the infections in these patients were caused by aerobic Gram-negative bacilli. Over the last 20 years, however, a shift in the bacterial spectrum towards Gram-positive cocci has been reported in the west,” wrote the researchers. “Although the exact cause of this shift is not known, long-dwelling intravascular devices, fluoroquinolone prophylaxis, and chemotherapy-induced mucositis have been implicated.”

Reference

Siddiqui B, Azmat R, Tikmani S, et al. Frequency of bloodstream infection in febrile neutropenic patients, experience from a developing country [published September 12, 2018]. Ann Med Surg. doi: 10.1016/j.amsu.2018.09.004.