Varicella and Zoster, 2019: DCN - Minnesota Dept. of Health

Varicella and Zoster, 2019

In 2019, 366 varicella cases (6.5 per 100,000 population) were reported. Two hundred ten (57%) were from the metropolitan area. Cases ranged from 28 days to 66 years of age. Fortyfour cases (12%) were <1 year, 123 (34%) were 1-6, 89 (24%) were 7-12, 40 (11%) were 13-17, and 70 (19%) were ≥18 years of age. Nine cases were hospitalized; 3 were <1 year, 1 was 1-17, and 5 were ≥18 years. Eight of the hospitalized cases had never been vaccinated; 3 were underage for vaccination, and the other 5 were adults who had never been offered the vaccine.

Varicella cases are often identified by parents/guardians reporting to schools and childcare facilities, rather than directly reported by a clinician. Of the 366 cases for which information regarding diagnosis was available, 264 (72%) had visited a health care provider, 18 (5%) had consulted a provider or clinic by telephone, 2 had been identified by a school health professional, and 82 (22%) had not consulted a health care provider. Of the 361 cases for which information regarding laboratory testing was available, 150 (41%) had appropriate testing performed. Seventeen percent of cases occurred as part of an outbreak, defined as ≥5 cases in the same setting. Four outbreaks occurred in schools. Three were private schools, and one was a public school. The largest outbreak had 8 cases; 1 case was partially vaccinated, 1 case had an unknown vaccination status, and 6 cases were unvaccinated. Of the unvaccinated cases, 4 were due to parental refusal, and 2 were unknown.

Zoster cases in children <18 years of age are reportable in Minnesota; 58 cases were reported in 2019. Cases may be reported by school health personnel, child care staff, or healthcare providers. Ages ranged from 1 to 17 years (median 9 years). Varicella vaccine became a requirement for entry into kindergarten and 7th grade in 2004, and the incidence of zoster in children has declined from 15.7 per 100,000 population in 2006 to 4.5 per 100,000 population in 2019.

Zoster with dissemination or complications (other than postherpetic neuralgia) in persons of any age is also reportable; 80 such cases were reported, and 66 were hospitalized. Cases ranged from 13 to 99 years of age, with a median age of 56. Forty-six (58%) had comorbidities or were being treated with immunosuppressive drugs. Twenty-six had disseminated rash or disease, 27 had meningitis, 20 had cellulitis or other bacterial superinfection, 9 had encephalitis, 3 had meningioencephalitis, and 6 had Ramsay-Hunt Syndrome. Cases with disseminated rash or disease tended to be older than cases with meningitis without dissemination (median age of 66 vs. 43 years), and were more likely to have immunocompromising conditions or immunosuppressive drug treatment (77% vs. 30%). Three deaths occurred; one had encephalitis and a disseminated infection, one had meningoencephalitis, and one had a disseminated infection. All deaths were in cases >65 years. Fifteen percent of cases ≥50 years of age had a record of receiving zoster vaccine.

Updated Monday, 19-Jul-2021 15:28:58 CDT