Revealing HIV epidemic dynamics and contrasting responses in two WHO Eastern European countries: insights from modeling and data triangulation.

OBJECTIVES: In the early 2000s, Estonia and Latvia experienced a rapidly growing HIV epidemic among people who inject drugs (PWID), and had, with Russia, the highest diagnosis rates in Europe. Understanding epidemic dynamics in both countries and how responses to HIV impacted them is essential to ending injection-driven epidemics. DESIGN: Statistical modeling, programmatic data collection, and triangulation. METHODS: Data on newly diagnosed HIV cases were used in a back-calculation model to estimate, for each country, trends in HIV incidence, time to diagnosis, and undiagnosed infections. Modeled estimates were then triangulated with programmatic data on harm reduction services, HIV testing, and ART. RESULTS: From 2007 to 2016, HIV incidence decreased in Estonia by 61% overall, for all exposure groups, and particularly for male PWID (97%), except men who have sex with men, where it increased by 418%. In Latvia, it increased by 72% overall. Median time to diagnosis decreased for male PWID in Estonia, from 3.5 to 2.6 years, but not in Latvia. In 2016, most new and undiagnosed infections, ∼50% in Latvia and ∼75% in Estonia, affected individuals reporting heterosexual transmission, showing a gradual shift toward heterosexual route as the main reported exposure mode. Coverage of services had been higher in Estonia; for example, by 2016, for PWID, there were >200 needles and syringes distributed per PWID annually, and HIV testing and ART coverage reached ∼50% and 76%, respectively, in Estonia, against respectively less than 100%, 10% and 27% in Latvia. CONCLUSIONS: Estonia has turned the tide of its epidemic - large scale-up of prevention and care programs probably contributed to it - whereas in Latvia it remains very active.

Mumps increase in Flanders, Belgium, 2012-2013: results from temporary mandatory notification and a cohort study among university students.

INTRODUCTION: In 2012, an increase in mumps notifications occurred in Belgium, affecting young vaccinated adults. At the end of 2012, a mumps outbreak occurred at the Catholic University of Leuven KU Leuven in Flanders. We investigated the outbreak to estimate incidence, mumps vaccine effectiveness and to detect potential risk factors for the disease. METHODS: In June 2012, we set up mandatory notification in Flanders and we collected information on circulating genotypes from the National Reference Centre. We conducted a cohort study among KU Leuven students. We defined a case as self-reported parotitis, between September 2012 and March 2013. We distributed web-based questionnaires to a random sample of students. We calculated vaccine effectiveness by comparing the risks in students vaccinated twice with those vaccinated once. We estimated risk ratios (RR) to identify risk factors. RESULTS: From 16th June 2012 to 1st April 2013, 4061 mumps cases were notified to the regional public health office (30% were vaccinated once and 69% were vaccinated twice). All 16 samples collected at the KU Leuven were genotype G5. Of 717 participants of the cohort study, 38 (5%; 95%CI 4-8%) met the case-definition. All reported being vaccinated with at least one dose of mumps-containing vaccine. The incidence of mumps was 5% among those vaccinated twice and 16% among those vaccinated once (vaccine effectiveness of two doses compared to one: 68%, 95%CI -24% to 92%). The risk of mumps was lower among those vaccinated with two doses of mumps-containing vaccine ≤10 years before (RR: 0.33, 95%CI 0.10-1.02) and higher among students working in a bar (RR: 3.6, 95%CI 1.8-7.0). CONCLUSIONS: Incomplete protection by two doses of mumps-containing vaccine, possible waning immunity and intense social contacts may have contributed to the occurrence of this outbreak in Flanders. Efforts to maintain high vaccination coverage with two doses remain essential. However, the reasons for low vaccine effectiveness must be further explored and additional immunological research for more immunogenic mumps vaccines is necessary.