High number of hospitalisations and non-classical presentations: lessons learned from a measles outbreak in 2017, Belgium.

We describe and analyse an outbreak of measles that affected Belgium early 2017. In total, 289 cases were reported, mostly (53%) in people 15 years or older. For 133 (46%) vaccination status was unknown and a further 117 (41%) were not vaccinated. According to national guidelines, 83 of the unvaccinated cases (29% of total cases) should have received minimum one dose of vaccine, but did not. One in five cases (21%) did not present with the classical triad of fever, rash and any of coryza, conjunctivitis or cough. Rash was the most sensitive symptom, being absent in only six cases. A large proportion of cases (125/289, 43%) required hospitalisation. In hospitalised patients, the most commonly observed complications were hepatic disorders (present in 58/125 hospitalised patients, 46%). Thirty-six of the cases (12%) were in healthcare workers and nosocomial spread contributed importantly to the outbreak. Older age at presentation, altered clinical presentations and presence of complications like hepatitis can delay the correct diagnosis of measles. Clinicians should maintain a high index of suspicion in any individual presenting with rash. If the elimination target is to be reached, catch-up vaccination campaigns should be intensified and target young adults and health care workers.

Prevalence and risk factors of measles seronegativity in a cohort of HIV-positive subjects: a retrospective study.

OBJECTIVES: Measles infection is a vaccine-preventable disease currently resurging in Europe. HIV-infected subjects are at higher risk of complications following measles infection. We investigated the risk factors associated with being seronegative in a cohort of HIV-infected subjects. METHODS: All HIV-infected subjects in our cohort who had a measles serological test performed between December 2005 and May 2017 were retrospectively identified. A measles immunoglobulin G (IgG) titre > 275 mIU/mL was considered protective. Risk factors were analysed using logistic regression. RESULTS: Measles serology was available in 273 of 3124 subjects in active follow-up (8.7%). The prevalence of measles seronegativity was 21.6% (59 of 273). In the univariate analysis, being born after 1970 and HIV infection by vertical transmission were both associated with a higher risk of measles seronegativity, while a nadir CD4 T-cell count < 200 cells/µL was associated with a lower risk of measles seronegativity. In the multivariate analysis, only being born after 1970 [odds ratio (OR) 4.9; 95% confidence interval (CI) 1.3-18.7] and vertical transmission (OR 7.7; 95% CI 3.3-18.3) were significantly associated with seronegativity. Among the vertically infected subjects with measles-mumps-rubella (MMR) immunization documentation, the median number of doses of vaccine received before testing was 2 (range 1-3). CONCLUSIONS: HIV-infected subjects born after 1970 and vertically infected subjects should be screened for measles seropositivity.