Varicella surveillance among the patient population in Belgian general practice between 2019 and 2021

Sherihane Bensemmane, Robrecht De Schreye

Keywords: Infectious diseases, varicella, Primary care, surveillance

Background:

Varicella is a preventable infectious disease caused by varicella-zoster virus (VZV). Usually, varicella is a mild or moderate illness. Although serious cases are rare, complications can occur and include superinfection of the skin or soft tissue, respiratory syndromes, and neurological manifestations, even death.
In Belgium, there is no mandatory notification for varicella cases. Furthermore, vaccination against varicella is not compulsory. The network of Sentinel General Practitioners (SGP) ensures varicella surveillance in primary care. During the period from 2006 to 2012, the incidence varied between 30.6 and 41.8 cases per 10000 person-years.

Research questions:

This study aims to update varicella surveillance among patients consulting Belgian general practices as it resumed in 2019.

Method:

A 3-year retrospective population-based study based on data collected by the SGP network. We conducted a web-based survey using LimeSurvey®. Registered cases from 2019 to 2021 were analyzed.

Results:

During the study period, 431 cases were reported. The majority of patients were female (51.5%). In this sample, only 1.2% of patients were vaccinated against VZV. Patients aged 1-4 years old represented 61.3%, the second most affected group (21.4%) was patients aged 5-14, then patients under 1 year old (8.6%).
Complications rarely occurred (3.5%). Moreover, the most common complication was superinfection of the skin.
Consistently with previous data, a seasonality with peaks in winter is observed. In 2019, incidence was 20/10000, 6.7/10000 in 2020 and 7.5/10000 in 2021.
Incidence decreased in 2020 and 2021 compared to 2019. This drop could be explained by COVID-19-related restrictions (e.g. physical contact restriction), as well as the impact of COVID-19 on consultation and reduced registration by GP’s due to increased work load.

Conclusions:

This study yields recent data on reported varicella cases reported in general practice in Belgium. Unsurprisingly, COVID-19-related situation lead to a decrease in cases. Furthermore, surveillance data from SGP network is consistent with the literature.

Points for discussion:

Appropriateness of varicella surveillance through general practice

Impact of covid-19 on surveillance activities

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