The median age of the 38 cases was 42 years (range: 2–81 years) and 25 were male (Table). The proportion of male cases was higher among cases acquired in Europe (14 males of 21 cases) compared with those acquired in China (8 males of 14 cases) although the difference was not statistically significant (chi-squared test: p = 0.6). There was no difference in median age by sex (males: 45 years; females: 38 years, k-sample median test, p = 1.0) or by whether infection was acquired in Europe or not (acquired in Europe: 47 years; acquired in China: 38 years, p = 0.2).