Assessing the sensitivity of surveillance for pneumonia in rural Thailand.

We conducted a household survey among Sa Kaeo residents to characterize self-reported health-seeking behavior for pneumonia and the proportion of individuals who seek care at a hospital to determine the coverage of a surveillance system. A 2-stage cluster sample was used to select households. A case of pneumonia was defined as a self-reported history of cough and difficulty breathing for at least 2 days or being given a diagnosis of pneumonia by a healthcare provider in the 12-month period beginning February 1, 2002, and ending January 31, 2003. Interviewers administered a structured questionnaire that asked about clinical illness and utilization of healthcare services. Among 1,600 households, 5,658 persons were surveyed, of whom 62 persons met the case definition. Of the 59 persons with complete data, 53 (90%, 95% CI: 79-96) sought medical care and 47 (80%, 95% CI: 67-89) sought care at a hospital facility in the province. Neither distance nor cost was reported as a barrier to seeking care. Most individuals with self-reported pneumonia sought care at the hospital level. Population-based surveillance can provide reliable estimates of hospitalized, chest radiograph-confirmed pneumonia in Sa Kaeo if adjustments are made to account for the proportion of individuals who access a hospital where radiologic assessment is available.

A household survey to assess the burden of influenza in rural Thailand.

Little is known about the disease burden of influenza in middle-income tropical countries like Thailand. The recent outbreak of avian influenza (H5N1) and studies on influenza from neighboring countries highlight the need for data on incidence, access to care, and health care cost. In May/ June 2003, we conducted a province-wide household survey using two-stage cluster sampling to determine the burden of influenza-like illness in Sa Kaeo Province. We used the total number of reported influenza that occurred in May 2003 and a prospective study of outpatient influenza in clinic patients to develop an estimate of the annualized incidence of influenza. Of 718 subjects, 16 (2.2%) suffered an episode of influenza-like illness in the preceding month; 14 sought care, of whom 7 went to a hospital facility. Fifty percent reported missing on average 3 days of work or school. The total individual cost per illness episode was 663 baht (15.78 US dollars). The proportion of outpatients with influenza-like illness caused by an influenza virus in May was 16% and the annualized influenza incidence was estimated to be 5,941/100,000 in Sa Kaeo Province. This survey adds to information indicating that in rural Thailand, the burden of influenza is substantial and costs associated with an illness episode are up to 20% of an average monthly income.