Epidemiology of radiographically-confirmed and bacteremic pneumonia in rural Thailand.

Pneumonia remains a leading public health concern in Thailand. Using population-based surveillance during January 2004-December 2006, we describe incidence, mortality, and bacterial etiologies of chest radiograph-confirmed pneumonia requiring hospitalization in one rural Thai province. Of 19,316 patients who met the case definition for clinical pneumonia, 9,596 (50%) had a chest radiograph, and 4,993 (52%) of those had radiographically-confirmed pneumonia. The incidence of radiographically-confirmed pneumonia ranged from 199 to 256 per 100,000 persons per year; 151 (3.0%) patients died. The annual average pneumonia mortality rate was 6.9 per 100,000 persons (range 6.2 to 7.8 per 100,000) and was highest in persons aged < 1 year (64/100,000) and > or = 65 years (44/100,000). Of 4,993 patients with radiographically-confirmed pneumonia, 1,916 (38%) had blood cultures, and 187 (10%) of those had pathogens isolated. Pathogens causing bacteremic pneumonia included B. pseudomallei (15% to 24% of bacterial pathogens), E. coli (9.2% to 25%), S. pneumoniae (7.9% to 17%), K. pneumoniae (2.2% to 6.4%), and S. aureus (4.3 to 5.3%). Bacteremia was significantly associated with pneumonia mortality after controlling for age, sex, HIV status and measures of disease severity in a logistic regression model (OR=5.2; 95% confidence interval= 2.2-12). Pneumonia remains an important cause of morbidity and mortality in Thailand, as in other countries in Southeast Asia. These findings can inform pneumonia clinical management and treatment decisions and guide public health programming, including the development of effective prevention strategies.

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.

Trends in liver cancer, Sa Kaeo Province Thailand.

OBJECTIVE: To determine liver cancer trends in Sa Kaeo Province, Thailand. METHODS: Death certificate (1993-2003) and hospital records (1999-2003) were reviewed and compared to national averages and other provinces. RESULTS: According to data from death certificates, liver cancer mortality in Sa Kaeo Province increased from 3.1 to 26.1 per 100,000 population between 1993 and 2003. In Thailand overall rates increased from 9.0 to 19.8 per 100,000 population between 1996 and 2003. According to electronic hospital records, the total number of patient encounters (in-patient admissions and out-patient visits) for liver cancer in the two main hospitals in Sa Kaeo Province increased 56% (14% annually) between 1999 and 2003. The number of cases of hepatocellular carcinoma increased from 42 in 2001 to 73 in 2003, while the number of cases of cholangiocarcinoma showed little change. CONCLUSIONS: Thailand as a whole and Sa Kaeo Province specifically have a high burden of liver cancer, which appears to have increased substantially in the past 10 years. Demonstrating the impact of ongoing strategies aimed at reducing risk factors for liver cancer, such as universal hepatitis B vaccination of infants, will require reliable data describing liver cancer disease burden and etiology. Rapid investigations using available data from death certificates, electronic admissions records, and patient charts can provide valuable insights on disease burden and trends.

Pneumonia surveillance in Thailand: current practice and future needs.

We reviewed reported pneumonia cases and deaths in Thailand since 1975 to evaluate the pneumonia surveillance system. In Sa Kaeo Province, we analyzed 3 years in detail (1999--2001) from electronic surveillance data, and compared deaths reported through surveillance to death certificate data in 1999 and 2000. In addition, we interviewed surveillance personnel who collected the data from all 7 hospitals and from a 10% random sample of health centers. Since the mid-1980s, reported illnesses and deaths from pneumonia have been increasing. In Sa Kaeo, an average of 925 pneumonia cases were reported each year, for an estimated average annual incidence of 211 per 100,000. The age-specific incidence peaked at 1,418 per 100,000 in children less than 5 years. In 1999 and 2000, there were 7 and 6 pneumonia deaths, respectively, reported through the surveillance system, compared with 28 and 53, respectively, reported by death certificate. Sixty-two (82%) of the 72 surveillance personnel reported receiving some training, but most of this was informal. Although written criteria to diagnose pneumonia were established in 1996, those who report cases did not know these criteria. A combination of physician, nurse, and public health workers diagnoses were used. According to the written criteria, cases of suspect or rule out pneumonia should be reported, but when asked about specific examples only 79% of persons interviewed said they would report "tuberculosis with pneumonia" and 44% would report "bronchitis, rule out pneumonia." Seventy-four percent of persons interviewed completed the surveillance report within one day of patient admission.