The use of capture-recapture methods to provide better estimates of the burden of norovirus outbreaks from seafood in England, 2004-2011

Using capture-recapture methods to estimate influenza hospitalization incidence rates

Background

Accurate population estimates of disease incidence and burden are needed to set appropriate public health policy. The capture–recapture (C‐R) method combines data from multiple sources to provide better estimates than is possible using single sources.

Methods

Data were derived from clinical virology test results and from an influenza vaccine effectiveness study from seasons 2016–2017 to 2018–2019. The Petersen C‐R method was used to estimate the population size of influenza cases; these estimates were then used to calculate adult influenza hospitalization burden using a Centers for Disease Control and Prevention (CDC) multiplier method.

Results

Over all seasons, 343 influenza cases were reported in the clinical database, and 313 in the research database. Fifty‐nine cases (17%) reported in the clinical database were not captured in the research database, and 29 (9%) cases in the research database were not captured in the clinical database. Influenza hospitalizations were higher among vaccinated (58%) than the unvaccinated (35%) in the current season and were similar among unvaccinated (51%) and vaccinated (49%) in the previous year. Completeness of the influenza hospitalization capture was estimated to be 76%. The incidence rates for influenza hospitalizations varied by age and season and averaged 307–309 cases/100,000 adult population annually.

Conclusion

Using C‐R methods with more than one database, along with a multiplier method with adjustments improves the population estimates of influenza disease burden compared with relying on a single‐data source.

Estimating the number of farms experienced foot and mouth disease outbreaks using capture-recapture methods

Foot and mouth disease (FMD) is recognized as an endemic disease in Thailand and throughout other countries in Southeast Asia. The underreporting of FMD outbreaks has affected the true status of the disease. This study aimed to determine the number of dairy farms in Chiang Mai that had experienced FMD outbreaks (FMD outbreak farm) during 2015-2016 using capture-recapture (CR) methods. Two independent FMD outbreak data sources including data from the livestock authorities and survey questionnaires were analyzed using Chapman estimator and Chao estimator. Results showed that the estimated number of FMD outbreak farms was 264 (95% CI = 250, 277) and 273 (95% CI = 259, 292) farms based on the Chapman estimator and Chao estimator, respectively. The estimated prevalence of FMD corresponding to the Chapman estimator was lower than the Chao estimator. The active approach of the survey method offered a higher degree of sensitivity compared to the passive method used by the livestock authorities. Estimations from the CR method provided an upper bound for the true number of outbreak farms. This study demonstrated the use of the CR method to estimate the true status of FMD outbreaks. Our proposed approach can potentially be used as a tool to enhance the accuracy and sensitivity of established monitoring and surveillance systems.

Using Capture-Recapture Methods to Estimate Local Influenza Hospitalization Incidence Rates

Background

Accurate population estimates of disease incidence and burden are needed to set appropriate public health policy. The capture-recapture (C-R) method combines data from multiple sources to better estimate prevalence than is possible using single sources. This study used the C-R method to estimate influenza cases using research and administrative databases to calculate county-wide influenza hospitalization burden.

Methods

Data were derived from a database of clinical virology test results and research data from an influenza vaccine effectiveness study from seasons 2015-2016 to 2018-2019. Missed influenza cases were estimated using C-R method. These estimates were used to calculate disease burden using the multiplier method to correct for underreporting due to curtailing data collection before the end of influenza circulation.

Results

Over all seasons, 422 influenza cases were reported in the administrative database and 382 influenza cases in the research database. Seventy-five cases (18%) reported in the administrative database were not captured in the research database, and 35 (9%) cases in the research database were not captured in the administrative database. Completeness of the influenza hospitalization was estimated to be 76%. Influenza hospitalizations were higher among unvaccinated (32%) than vaccinated (22%) in the current season and among unvaccinated (28%) than vaccinated (23%) in the previous year. The incidence rates for influenza hospitalizations varied by age and season and averaged 421 cases/100,000 population annually.

Conclusion

The capture-recapture method offers a more accurate method for estimating influenza hospitalization than relying on a single data source. Using the multiplier method with adjustments improves the detection of influenza disease burden through a matched database. The incidence rates are consistent with national estimates.