No 22/24 - 2024

Epidemiology of parvovirus B19 epidemic

In the spring of 2024, Denmark observed an increase in the incidence of the fifth disease, caused by parvovirus B19 as described in EPI-NEWS 13/2024. The heightened incidence has been monitored closely by Statens Serum Institut, and an outbreak page was established, which is updated every other week until the epidemic starts following a declining trend.

Statens Serum Institut, in collaboration with Danish clinicians, has conducted a study describing the comprehensive parvovirus epidemic of this spring by merging data from various registries. This study was recently published in an article in Eurosurveillance to raise awareness in Denmark and Europe regarding the ongoing parvovirus situation, given that several countries are witnessing similar trends.

The most notable aspect of the 2024 epidemic is an exceptionally high number of cases compared to previous epidemics. Typically, parvovirus B19 infection results in mild illness that does not require treatment. However, in rare cases, the infection may lead to severe illness in pregnant women and immunocompromised individuals. Hence, it is important to focus on the condition in these specific patient groups. Transmission to the foetus may occur if a seronegative pregnant woman becomes infected with parvovirus. In very rare cases, the foetus may develop anaemia, hydrops foetalis (severe fluid accumulation) or foetal death. Among pregnant women with parvovirus infection in Denmark during this epidemic, 12.3% (16/130) experienced severe complications.

The risk of severe complications is higher when infection occurs before the 20th week of gestation. However, if there is suspicion of infection in a pregnant woman, testing is warranted irrespective of gestational week. The pregnant woman should be referred to a specialised department upon confirmation of parvovirus infection.

(A.C. Nordholm and M. Wessman, Department of Infectious Epidemiology and Prevention)

Nordic Vaccine Meeting in Copenhagen

The Nordic Vaccine Meeting is held biennially in rotation among the five Nordic countries, providing a platform to convene and discuss vaccine development, programmatic application and vaccination policies in the Nordic countries. This year, the Nordic Vaccine Meeting will take place in Copenhagen in September. The meeting is organised by Statens Serum Institut in collaboration with the Danish Health Authority. The scientific agenda encompasses topics such as RSV vaccination, vaccination of pregnant women and inequality in vaccination. If you are interested in vaccines and vaccine-preventable diseases, this event offers an enriching experience replete with insightful discussions and valuable networking opportunities. More information about the meeting programme and registration is available on at the Nordic Vaccine Meeting site.

(J. Grau, T. Dalby, A.C. Nordholm, P.H. Andersen, Department of Infectious Epidemiology and Prevention)