- Salje, Henrik;
- Cauchemez, Simon;
- Alera, Maria Theresa;
- Rodriguez-Barraquer, Isabel;
- Thaisomboonsuk, Butsaya;
- Srikiatkhachorn, Anon;
- Lago, Catherine B;
- Villa, Daisy;
- Klungthong, Chonticha;
- Tac-An, Ilya A;
- Fernandez, Stefan;
- Velasco, John Mark;
- Roque, Vito G;
- Nisalak, Ananda;
- Macareo, Louis R;
- Levy, Jens W;
- Cummings, Derek;
- Yoon, In-Kyu
Proper understanding of the long-term epidemiology of chikungunya has been hampered by poor surveillance. Outbreak years are unpredictable and cases often misdiagnosed. Here we analyzed age-specific data from 2 serological studies (from 1973 and 2012) in Cebu, Philippines, to reconstruct both the annual probability of infection and population-level immunity over a 60-year period (1952-2012). We also explored whether seroconversions during 2012-2013 were spatially clustered. Our models identified 4 discrete outbreaks separated by an average delay of 17 years. On average, 23% (95% confidence interval [CI], 16%-37%) of the susceptible population was infected per outbreak, with >50% of the entire population remaining susceptible at any point. Participants who seroconverted during 2012-2013 were clustered at distances of <230 m, suggesting focal transmission. Large-scale outbreaks of chikungunya did not result in sustained multiyear transmission. Nevertheless, we estimate that >350 000 infections were missed by surveillance systems. Serological studies could supplement surveillance to provide important insights on pathogen circulation.