Outcome of respiratory viral infection in neutropenic host: implication on traditional therapeutic approach

Abstract

OBJECTIVES: Children with acquired neutropenia are prone to bacterial and fungal infection. Early introduction of aggressive antibiotic treatment is mandatory to minimize fatal infection. In standard practice, empirical broad spectrum antibiotics have to be given for at least 5 days or even longer. But in up to 75% of children with neutropenic fever, causative agents cannot be identified and the role of viral infection has not been properly addressed. We reviewed our experience in managing children with neutropenic fever and the outcome of respiratory viral infection in neutropenic patients were analyzed. METHODS: We performed a retrospective review on paediatric patients admitted to our haematology/oncology ward between 1st July to 31th December 1996. Only children (<= 15-year-old) with moderate to severe neutropenia (ANC <= 1x109/L) and fever (core temperature >= 38°C x 2 or >= 38.5°C x 1) were included in this study. Blood smear and culture were performed in all patients. The smear result usually returned within 12 hrs and culture results returned within 3 days. Nasopharyngeal aspirates (NPA) were performed in children with concomitant signs and symptoms of respiratory tract infection. The aspirates were tested for adenovirus (Adeno), influenza A & B (Flu), parainfluenza 1, 2. & 3 (paraflu) and respiratory syncytial virus (RSV) by immunofluorescence method. The aspirate results were usually available between 6 to 24 hrs. Concerning treatment, all patients were treated with standard antibiotic regimens. RESULTS: Within this 6 months period, 84 episodes of neutropenic fever were diagnosed in 48 patients. Except 3 patients with aplastic anaemia, all others had chemotherapy-induced neutropenia. 38 (45%) episodes had respiratory symptoms and 21/38 (56%) were found to have respiratory viruses (RSV n=9, Paraflu 3 n=10, Flu A n=2). 26/84 (31%) of blood cultures were positive for bacteria or fungus. Among the positive blood cultures, gram positive (gm+) organisms accounted for the majority (19/26, 73% Staphylococcus species n=12, Bacillus species n=6 and pneumococcus n=1). All episodes of gm+ infection had central venous catheter installed. 6/26 had gram negative (gm-) bacilli (Klebsiella species n=3, Acinectobacter baumaunii n=1, E.coli n=1 & Pseudomonas pickettii n=1) and 1/26 had systemic Candidia albican infection. Concomitant viral respiratory infection and positive blood cultures were found in 2 patients, both had line infection by gm+ organisms. All patients with documented viral respiratory infection recovered within a week and no significant complications were noted. Whereas those without evidence of viral respiratory infection had variable outcome. One patient with Klebsiella septicaemia died and two patients with no growth in their blood cultures died during their neutropenic fever period. CONCLUSIONS: Neutropenic children with viral respiratory infection is common in our patient cohort. If without concomitant systemic bacterial or fungal infection, this group of patients had a good outcome. Further study should be designed to test the feasibility of stopping antibiotics early in this group of patients.