Argentina reports surge in leptospirosis and influenza A (H3N2) cases

The Argentine Ministry of Health’s latest epidemiological bulletin shows a 28% rise in leptospirosis notifications for weeks 1‑15 of 2026, with 109 reports (45 confirmed, 64 probable). Incidence is highest in the NEA and Centro regions, especially Santa Fe (39 cases), Buenos Aires (28) and Entre Ríos (15). Most patients are men, median age 38.

Respiratory viruses are also increasing, driven almost entirely by influenza A(H3N2). Test positivity grew from 33.3% to 42.2% in week 18, and the sub‑clade J.2.4.1(K) now accounts for 92% of sequenced H3N2 samples. In Santa Fe, a 64‑year‑old man died from influenza A in Rosario after not receiving the seasonal flu vaccine. The province recorded 12,180 hospitalisations for acute respiratory infections, with 269 confirmed viral cases, the majority influenza A. Additionally, psittacosis cases in Santa Fe rose to 98 suspected (50 confirmed or probable). Health officials urge vaccination and continued surveillance.