Epidemic activity after natural disasters without high mortality in developing settings

Natural disasters with minimal human mortality rarely capture headlines but occur frequently and result in significant morbidity and economic loss. We compared the epidemic activity observed after a flood, an earthquake, and volcanic activity in Peru. Following post-disaster guidelines, healthcare facilities and evacuation centers surveyed 10–12 significant health conditions for ~45 days and compared disease frequency with Poisson regression. The disasters affected 20,709 individuals and 15% were placed in evacuation centers. Seven deaths and 6,056 health conditions were reported (mean: 0.29 per person). Health facilities reported fewer events than evacuation centers (0.06–0.24 vs. 0.65–2.02, P < 0.001) and disease notification increased 1.6 times after the disasters (95% CI: 1.5–1.6). Acute respiratory infections were the most frequent event (41–57%) and psychological distress was second/third (7.6% to 14.3%). Morbidity increased after disasters without substantial casualties, particularly at evacuation centers, with frequent respiratory infections and psychological distress. Post-disaster surveillance is valuable even after low-mortality events.