Bayesian latent class estimation of the incidence of chest radiograph-confirmed pneumonia in rural Thailand.

Pneumonia is a leading cause of mortality and morbidity worldwide with radiographically confirmed pneumonia a key disease burden indicator. This is usually determined by a radiology panel which is assumed to be the best available standard; however, this assumption may introduce bias into pneumonia incidence estimates. To improve estimates of radiographic pneumonia incidence, we applied Bayesian latent class modelling (BLCM) to a large database of hospitalized patients with acute lower respiratory tract illness in Sa Kaeo and Nakhon Phanom provinces, Thailand from 2005 to 2010 with chest radiographs read by both a radiology panel and a clinician. We compared these estimates to those from conventional analysis. For children aged <5 years, estimated radiographically confirmed pneumonia incidence by BLCM was 2394/100 000 person-years (95% credible interval 2185-2574) vs. 1736/100 000 person-years (95% confidence interval 1706-1766) from conventional analysis. For persons aged ⩾5 years, estimated radiographically confirmed pneumonia incidence was similar between BLCM and conventional analysis (235 vs. 215/100 000 person-years). BLCM suggests the incidence of radiographically confirmed pneumonia in young children is substantially larger than estimated from the conventional approach using radiology panels as the reference standard.

Acinetobacter bacteraemia in Thailand: evidence for infections outside the hospital setting.

SUMMARY: Acinetobacter is a well-recognized nosocomial pathogen. Previous reports of community-associated Acinetobacter infections have lacked clear case definitions and assessment of healthcare-associated (HCA) risk factors. We identified Acinetobacter bacteraemia cases from blood cultures obtained <3 days after hospitalization in rural Thailand and performed medical record reviews to assess HCA risk factors in the previous year and compare clinical and microbiological characteristics between cases with and without HCA risk factors. Of 72 Acinetobacter cases, 32 (44%) had no HCA risk factors. Compared to HCA infections, non-HCA infections were more often caused by Acinetobacter species other than calcoaceticus-baumannii complex species and by antibiotic-susceptible organisms. Despite similar symptoms, the case-fatality proportion was lower in non-HCA than HCA cases (9% vs. 45%, P < 0·01). Clinicians should be aware of Acinetobacter as a potential cause of community-associated infections in Thailand; prospective studies are needed to improve understanding of associated risk factors and disease burden.

Incidence of respiratory pathogens in persons hospitalized with pneumonia in two provinces in Thailand.

Although pneumonia is a leading cause of death from infectious disease worldwide, comprehensive information about its causes and incidence in low- and middle-income countries is lacking. Active surveillance of hospitalized patients with pneumonia is ongoing in Thailand. Consenting patients are tested for seven bacterial and 14 viral respiratory pathogens by PCR and viral culture on nasopharyngeal swab specimens, serology on acute/convalescent sera, sputum smears and antigen detection tests on urine. Between September 2003 and December 2005, there were 1730 episodes of radiographically confirmed pneumonia (34·6% in children aged <5 years); 66 patients (3·8%) died. A recognized pathogen was identified in 42·5% of episodes. Respiratory syncytial virus (RSV) infection was associated with 16·7% of all pneumonias, 41·2% in children. The viral pathogen with the highest incidence in children aged <5 years was RSV (417·1/100,000 per year) and in persons aged ≥50 years, influenza virus A (38·8/100,000 per year). These data can help guide health policy towards effective prevention strategies.