The 2024 Outbreak of Parvovirus B19 as a Global Obstetrical Threat Insights From an Obstetrics Referral Center in Northern Italy

Abstract

A significant increase in Parvovirus B 19 (B19V) infections has been reported in the last months in some European countries. This outbreak could be highly detrimental for pregnant women, considering the capacity of the virus to harm the fetus. However, the magnitude and spread of this outbreak is yet unclear. Evidence from other areas is required and there is the need to focus more on the impact on pregnancy. To this aim, pregnant women with B19V infection who were managed in a referral hospital located in Milan, Northern Italy were reviewed. The primary aim was comparing the number of ascertained cases of B19V infection in the period January-July 2024 to the number of cases recorded in the previous 9 years (2015-2023). Overall, the number of B19V infections markedly increased in the first 7 months of 2024. Until 2023, the number of cases per year were below 7, with no cases reported in 2020-2022, while in the period January-July 2024, the number raised to 59 (p < 0.001). Maternal characteristics and fetal outcomes before and after January 2024 did not differ. In conclusion, Italy is also involved in the ongoing outbreak of B19V infection and pregnant women are exposed to this threat. Synopsis: An outbreak of Parvovirus B19 infections is currently ongoing in Italian pregnant women.

Keywords: Parvovirus b19; infection; outbreak; pregnancy.

Figure 1

Distribution of the number of pregnant women with Parvovirus B19 infections referred to the Referral hospital in Obstetrics, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico (Milan, Italy), in the period 2015–2024. The distribution does not fit the null hypothesis of a uniform distribution (corresponding to a theoretical infection rate stable over time) (p < 0.001). The distribution does not fit a uniform model also when excluding the 2024 cases because of the absence of cases in 2020‐2022 (p = 0.006).