Changing epidemiology of parvovirus B19 in the Netherlands since 1990, including its re-emergence after the COVID-19 pandemic.

Parvovirus B19V (B19V) infection during pregnancy can be complicated by potentially life-threatening fetal hydrops, which can be managed by intrauterine transfusion (IUT). This study investigates the long-term temporal patterns in the epidemiology of B19V and evaluates the impact on fetal hydrops, by combining data on B19V infections from the Dutch Sentinel Surveillance system in the period 1990 to 2023, Dutch blood banking data and hospital data on fetal hydrops. Using wavelet analysis, we identified annual epidemic cycles in the Netherlands in the period 1990-2019 and we identified superimposed multiannual cycles in the period 1990-2009. After 2009, no multiannual cycle could be identified, although the incidence fluctuated and correlates with number of IUT performed. As of 2020, weekly reports of B19V infection demonstrated a historically low incidence and B19V-DNA positive blood donors were nearly absent. From May 2020 to May 2023, no IUT for B19V-related hydrops was performed. In the spring of 2023, B19V infections re-emerged, reaching pre-pandemic epidemic levels. Due to the changes in B19V epidemiology over the last 30 years and the near-absence of B19V during the COVID-19 pandemic, the resulting low immunity levels may lead to rebound outbreaks. Alertness to severe complications such as fetal hydrops is warranted.

Valganciclovir in Infants with Hearing Loss and Clinically Inapparent Congenital Cytomegalovirus Infection: A Nonrandomized Controlled Trial.

OBJECTIVE: To assess the efficacy of valganciclovir in infants with hearing loss and clinically inapparent congenital cytomegalovirus infection (cCMV), as there is no consensus on treatment of this group. STUDY DESIGN: A nationwide, nonrandomized controlled trial, comparing 6 weeks of oral valganciclovir to no treatment in infants with cCMV, recruited after newborn hearing screening resulted in referral to an audiologist. The choice whether to treat was left to parents of subjects. Eligible subjects were full term infants aged <13 weeks with sensorineural hearing loss and diagnosed with cCMV through dried blood spot testing. The primary outcome, measured by linear and ordinal logistic regression, was change in best-ear hearing from baseline to follow-up at 18-22 months of age. RESULTS: Thirty-seven participants were included in the final analysis, of whom 25 were in the treatment group and 12 in the control group. The majority of subjects in both groups had neuroimaging abnormalities, which were mostly mild. Hearing deterioration was more likely in the control group compared with the treatment group (common OR 0.10, 95% CI 0.02-0.45, P = .003). Mean best-ear hearing deteriorated by 13.7 dB in the control group, compared with improvement of 3.3 dB in the treatment group (difference 17 dB, 95% CI 2.6 - 31.4, P = .02). CONCLUSIONS: We investigated treatment in children with hearing loss and clinically inapparent cCMV. Although our study was nonrandomized, it is the first prospective and controlled trial in this population. Valganciclovir-treated children with hearing loss and inapparent cCMV had less hearing deterioration at 18 through 22 months of age than control subjects. EUDRACT REGISTRY NUMBER: 2013-003068-30.