Epidemiological Situation

Following an unusually low level of dengue virus circulation in 2017, including during the southern winter, an increase in viral circulation has been observed each week since January 2018.During the past week (March 19–25), 154 cases were confirmed, bringing the total number of cases reported in 2018 to 588, all of which are locally acquired. Since the beginning of 2017, a total of 682 locally acquired cases and 9 imported cases have been confirmed. The cases reported during the past week are primarily located:

• in the west in St-Paul, Gare Routière, and Etang (35 cases), Bois de Nèfles and La Plaine (29 cases), in La Possession (11 cases), Le Port (3 cases), St Gilles-les-Bains (29 cases), St-Gilles-les-Hauts (4 cases), La Saline (3 cases), St-Leu (5 cases).

• in the south in St-Pierre (8 cases), Ravine des Cabris, and Bois d'Olives (6 cases)

Isolated cases have also been identified in Saint-Denis (4 cases), Sainte-Marie (2 cases), Trois Bassins (1 case), Saint-Louis (4 cases), Le Tampon (1 case), and Saint-Joseph (1 case). Ongoing investigations will help identify their places of infection. Since early 2017, among locally acquired cases, the predominant serotype has been DENV-2 (345 genotypes). The other viruses identified are DENV-1 (4 genotypes) and DENV-4 (1 genotype), primarily in imported cases in 2017. In 2016, co-circulation of DENV-1, DENV-2, and DENV-3 viruses was observed, with DENV-1 being the most prevalent.Of the 682 confirmed cases since 2017, 52 cases (8%) are children under 15 years of age, and 103 cases (15%) are aged 65 or older.