Varicella (Chickenpox) in Florida

The number of varicella cases reported in September 2024 increased from the previous month and was below the previous 5-year average. Due to robust vaccination programs, there is no longer discernable seasonality for varicella cases in the United States.

In September 2024, 40 varicella cases were reported in 19 counties, outlined in black in the map. From July 2024 through September 2024 the average county rates varied throughout the state.

In 2024, 570 varicella cases were reported. The annual number of reported varicella cases increased from 2018 to 2019 and decreased significantly in 2020, 2021 and 2022. Cases reported in 2023 returned to levels similarly observed prior to the 2020 pandemic.
*CDC MMWR report year

In September 2024, the varicella rate was highest among <1 - 5 year olds at 1.02 cases per 100,000 population. Infants <1 year old are too young to receive varicella vaccination, which is why vaccination of siblings, parents, grandparents, and other age groups is important in infection prevention among infants.

In September, 14 cases were household-associated and 2 cases were outbreak-associated. For most varicella cases, exposure to other known cases is not identied. In Florida, transmission setting is not routinely identied for non-outbreak cases.

People with shingles infection can transmit the virus that causes varicella to people without immunity. In September, 1 case reported having contact with someone diagnosed with shingles during their exposure period.

In September 2024, 68% of cases reported with varicella had not received the recommended number of varicella vaccinations for their age or had unknown vaccination status. Vaccination against varicella is important for infants, children, teenagers, and adults. If a person was born before September 1, 1994, the current varicella immunization recommendation would not have been implemented when they were receiving their childhood immunizations. Based on the case’s age, 121 cases in 2024 would not have been vaccinated under the current childhood immunization recommendations.

In 2024, the majority of adults aged 19 years and older with varicella were not up-to-date on their varicella vaccinations or had unknown vaccination status. Although individuals who have been vaccinated can still develop varicella, complete and timely vaccination remains the best way to prevent varicella and severe complications.