Title : Association between respiratory tract viral PCR panel results and clinical outcomes in children with cancer and febrile neutropenia
Abstract:
Febrile neutropenia (FEN) is the most common life-threatening complication of childhood cancer. Early initiation of broad-spectrum intravenous antibiotics to patients has reduced the mortality of FEN below 5%. Studies have reported viral infections to constitute 35 to 55% of FEN episodes in pediatric patients. In healthy children, these viruses usually cause upper respiratory tract infections, with a self- limited course. However, they can lead to significant morbidity and mortality in immunocompromised patients. It has also been shown that viral respiratory tract infections are more common in cancer patients than in immunocompetent patients. Up to around half of these infections are of viral origin, but viral infections are often difficult to distinguish from bacterial infections. With multiplex real-time polymerase chain reaction (PCR), the diagnosis of respiratory viruses has increased by 30 to 50%. Respiratory tract viruses were found to be positive in between 38 and 76% in children with cancer and FEN when using PCR. In five studies performed on patients with respiratory tract complaints and findings, the PCR positivity rate was between 34 and 76%. These rates ranged from 34 to 93.75% in five studies where the patients had presented with FEN. PCR positivity was reported as 35 and 78% in the two studies including patients with a positive focus of infection but only 22% in the study conducted in patients presenting with fever. PCR positivity ranged from 45 to 68% in three studies with respiratory tract complaints and an episode of FEN. It should be noted that a positive RVP is not necessarily associated with a clinically significant systemic RVI. Previous research has shown that respiratory viral shedding can occur in asymptomatic patients for up to 6 weeks following RVI. In the literature, the rate of viral coinfection varied between 19.5 and 55%. Torres et al reported that the high prevalence of febrile RVIs contributed to the increase in the rate of FEN in pediatric patients with cancer. Krause et al showed that RVIs were associated with treatment delays and increased frequency of hospitalization in pediatric cancer patients. It was reported that the severity of the infection was low in PCR- positive cases. In two different studies, it was reported that patients with only PCR positivity but without blood culture positivity had shorter hospital LOS and lower PICU admission rates. It should be borne in mind that frequency of viral type detected will change seasonally. Another reason for requesting RVP in a patient presenting with FEN would be to aid in selection of drugs to be added to the treatment. However, given that having a positive RVP does not affect LOS or disease severity, the question remains whether RVP testing contributes to clinical management in this population. Future research should also investigate if RVP positivity affects clinician decision-making or parental reassurance at discharge of pediatric patients with cancer and with FEN.
