RSV infection in Istanbul: risk factors and frequency

Abstract

Introduction: Respiratory syncytial virus (RSV) is one of the most common causes of acute respiratory infections in all age groups especially under two years. The aim of this study was to investigate the frequency and clinical features of RSV in hospitalized children under two years of age with the diagnosis of lower respiratory tract infections (LRTI) in our region. Methodology: Between September 2011-May 2013, hospitalized children aged 0-2 years with the diagnosis of viral LRTI, in which nasopharengeal secretions were tested for the presence of the RSV antigen, were included in this prospective study. Results: Among the total of 361 hospitalized children who were investigated for RSV antigen, 138 (38%) were female and 223 (62%) were male. The mean age of the group was 5,7±5,1 months (0-24 months). RSV antigen in nasopharyngeal secretions was positive in 68 (19%) of 361 patients. RSV infection was detected significantly higher in December and January (p = 0.003). RSV positivity was significantly higher in patients aged under 6 months (p=0.01), with shorter duration of breastfeeding (p = 0.02), low socioeconomic status (p = 0.02), and also born with spontaneous vaginal delivery (p = 0.007). In RSV(+) LRTI group, children were associated with severe disease than RSV (-LRTI group (p = 0.014). Conclusions: Since there is lack of data investigating the frequency and the risk factors of RSV respiratory infections in our region, the present study is important for providing new data. Furthermore, this is the second study investigating the correlation between RSV positivity and meteorological conditions in Turkey.

Prevalence and Risk Factors of Respiratory Syncytial Virus in Children under 5 Years of Age in the WHO European Region: A Systematic Review and Meta-Analysis

“…Climatic factors also contribute to promoting RSV infection. Like our results, many studies have highlighted that colder temperatures during the months with the highest RSV prevalence are associated with a greater probability of hospitalization for RSV [ 51 , 57 ]. Furthermore, the positivity of RSV is also higher in environmental conditions of high relative humidity, high atmospheric pressure and even wind speed [ 51 , 61 ].…”

“…Other authors, as in this study, consider the importance of exposure to tobacco smoke as a risk factor for RSV infection, aggravating the severity of bronchiolitis or the risk of other acute lower respiratory tract infections [ 62 ], although others do not find this association [ 51 , 63 ].…”

“…These results are similar to those of other studies that confirm a significantly higher rate in children under 3 years of age (19.5%) compared to children over 3 years of age (5.6%) [ 47 ]. Even multicenter studies find that in children under 6 months the prevalence is 50% and in children under 2 years of age 88%, a fact that corroborates the high burden of RSV in children < 2 years, especially in infants < 6 months [ 50 , 51 ]. The younger the age, the greater the risk of RSV infection, as corroborated by several authors, indicating a greater risk especially in children between 3 to 5 months [ 48 , 52 , 53 ], although other studies point out that RSV-associated hospitalizations reach their maximum peak in children under 3 months [ 54 ].…”

“…Episodes of infection usually occur between November and March, with a peak in January–February [ 51 ]. Even some studies when analysing the percentage of RSV infection and its relationship with the month of birth, find a low prevalence for children born in April of 5.7%, being higher in children born in November, of 49.6% [ 60 ].…”

“…RSV positivity is higher in children with characteristics such as low socioeconomic status and the length of the children’s hospital stay also has a negative influence [ 51 ]. In this review, we did not find a relationship between maternal aspects and RSV infection, while other studies indicate a short duration of breastfeeding as a risk factor as well as being born by spontaneous vaginal delivery [ 51 ].…”