The 2017–2018 influenza season in Bucharest, Romania: epidemiology and characteristics of hospital admissions for influenza-like illness

Abstract

BackgroundSeasonal influenza causes a considerable burden to healthcare services every year. To better measure the impact of severe influenza cases in Romania, we analyzed active surveillance data collected during the 2017–2018 season from patients admitted for influenza-like illness (ILI) at a tertiary care hospital in Bucharest.MethodsPatients admitted for acute ILI were included if they were resident in the Bucharest-Ilfov region, had been hospitalized for at least 24 h, and had onset of symptoms within 7 days before admission. Patient demographics, healthcare use, vaccination status, and outcome data were collected by questionnaire or by searching clinical records. Respiratory swabs were also obtained from each patient to confirm influenza A (A/H1 and A/H3 subtypes) or influenza B (Yamagata and Victoria lineages) infection by real-time reverse-transcription polymerase chain reaction assay.ResultsThe study included 502 patients, many (45.2%) of whom were aged < 5 years. Overall, 108 patients (21.5%) had one or more comorbidities. Seventeen adults aged 18–64 years (3.4%) had been vaccinated against influenza. Patients were hospitalized for a median of 5 days and most (90.4%) were prescribed antiviral treatment. More than one-half of the patients (n = 259, 51.6%) were positive for influenza. Most influenza cases were caused by B viruses (172/259, 66.4%), which were mostly of the B/Yamagata lineage (85 of 94 characterized, 90.4%). Most of the subtyped A viruses were A/H1 (59/74, 79.7%). A/H1 viruses were frequently detected in influenza-positive admissions throughout the 2017–2018 season, whereas the predominant B/Yamagata viruses were detected around the middle of the season, with a peak in cases at week 7 of 2018. Eleven patients were admitted to an intensive care unit; of these, one patient with confirmed B/Yamagata infection died.ConclusionsThese results show that seasonal influenza results in considerable hospitalization in Bucharest-Ilfov, Romania and suggest vaccine coverage should be extended, especially to the youngest age groups. The data from this study should help inform and optimize national influenza healthcare policies.

Surveillance of medically‐attended influenza in elderly patients from Romania—data from three consecutive influenza seasons (2015/16, 2016/17, and 2017/18)

“…The overall low vaccination uptake in our study population and in the country precluded us from performing an analysis of vaccine effectiveness for this study site. Also, lineage determination was only performed for a small proportion of B viruses circulating in the third influenza season investigated, which did not allow an exact quantification of the circulation of B/Victoria vs. B/Yamagata strains, but our data, corroborated with other information from field literature, showed that in the 2017/18 season in the Bucharest‐Ilfov region B/Yamagata accounted for 90.4% of all characterized B strains circulating in hospitalized influenza 25 …”

“…For the 2017/18 season, the predominance of B viruses was evident in our SARI study, accounting for 86.9% of all influenza cases, but the rate was higher than the one reported for ILI‐based surveillance at the national level (66.5%) 24 . In our study, lineage determination was only performed for a small proportion of B viruses circulating during this season (11.3%, 6/53 cases), but based on the results available from a different study concomitantly conducted in our hospital in the 2017/18 season, B/Yamagata appeared to be the main circulating strain in patients of all ages 25 …”

Clinical and molecular epidemiology of influenza viruses from Romanian patients hospitalized during the 2019/20 season

“…In our population, we have seen a predominance of pediatric patients among cases of LCI. While this may reflect to a certain extent a real increased circulation of influenza viruses among young children, who are known to be a risk group for influenza, this may also be driven at least in part by an increased addressability of pediatric patients with ILI to tertiary care rather than primary care services in our country, as previously discussed [19,20]. Furthermore, a potential propensity towards managing fever and administering antiviral treatment in children in the hospital rather than as outpatients cannot be ruled out, and this is probably reflected in the rather short 5 days median length of hospitalization in infants and toddlers.…”

Circulation of influenza A viruses among patients hospitalized for severe acute respiratory infection in a tertiary care hospital in Romania in the 2018/19 season

“…For example, in Romania, there was a completely heterogeneous circulation in the 3 seasons that preceded the one reported in this study: in 2015/16 influenza A/H1 predominated, [7] in 2016/17 influenza A/H3, [8] and in 2017/18 influenza B circulated in more than two-thirds of cases. [ 9 10 ] For this reason, epidemiological surveillance is needed to detect temporal trends and to make informed decisions and projections regarding the upcoming influenza seasons. Under these conditions, laboratory confirmation of influenza, especially through molecular techniques, is important because it guides clinical therapeutic decisions.…”