Background: Bloodstream infection (BSI) surveillance is essential to characterize the public health threat of bacteremia. We summarize BSI epidemiology in rural Thailand over an eight year period. Methods: Population-based surveillance captured clinically indicated blood cultures and associated antimicrobial susceptibility results performed in all 20 hospitals in Nakhon Phanom (NP) and Sa Kaeo (SK) provinces. BSIs were classified as community-onset (CO) when positive cultures were obtained ≤2 days after hospital admission and hospital-onset (HO) thereafter. Hospitalization denominator data were available for incidence estimates for 2009-2014. Results: From 2007 to 2014 a total of 11,166 BSIs were identified from 134,441 blood cultures. Annual CO BSI incidence ranged between 89.2 and 123.5 cases per 100,000 persons in SK and NP until 2011. Afterwards, CO incidence remained stable in SK and increased in NP, reaching 155.7 in 2013. Increases in CO BSI incidence over time were limited to persons aged ≥50 years. Ten pathogens, in rank order, accounted for > 65% of CO BSIs in both provinces, all age-groups, and all years: Escherichia coli, Klebsiella pneumoniae, Burkholderia pseudomallei, Staphylococcus aureus, Salmonella non-typhi spp., Streptococcus pneumoniae, Acinetobacter spp., Streptococcus agalactiae, Streptococcus pyogenes, Pseudomonas aeruginosa. HO BSI incidence increased in NP from 0.58 cases per 1000 hospitalizations in 2009 to 0.91 in 2014, but were higher (ranging from 1.9 to 2.3) in SK throughout the study period. Extended-spectrum beta-lactamase production among E. coli isolates and multi-drug resistance among Acinetobacter spp. isolates was common (> 25% of isolates), especially among HO cases (> 50% of isolates), and became more common over time, while methicillin-resistance among S. aureus isolates (10%) showed no clear trend. Carbapenem-resistant Enterobacteriaceae were documented in 2011-2014. Conclusions: Population-based surveillance documented CO BSI incidence estimates higher than previously reported from Thailand and the region, with temporal increases seen in older populations. The most commonly observed pathogens including resistance profiles were similar to leading pathogens and resistance profiles worldwide, thus; prevention strategies with demonstrated success elsewhere may prove effective in Thailand.

Background.: Antibiotic exposure and specimen volume are known to affect pathogen detection by culture. Here we assess their effects on bacterial pathogen detection by both culture and polymerase chain reaction (PCR) in children. Methods.: PERCH (Pneumonia Etiology Research for Child Health) is a case-control study of pneumonia in children aged 1-59 months investigating pathogens in blood, nasopharyngeal/oropharyngeal (NP/OP) swabs, and induced sputum by culture and PCR. Antibiotic exposure was ascertained by serum bioassay, and for cases, by a record of antibiotic treatment prior to specimen collection. Inoculated blood culture bottles were weighed to estimate volume. Results.: Antibiotic exposure ranged by specimen type from 43.5% to 81.7% in 4223 cases and was detected in 2.3% of 4863 controls. Antibiotics were associated with a 45% reduction in blood culture yield and approximately 20% reduction in yield from induced sputum culture. Reduction in yield of Streptococcus pneumoniae from NP culture was approximately 30% in cases and approximately 32% in controls. Several bacteria had significant but marginal reductions (by 5%-7%) in detection by PCR in NP/OP swabs from both cases and controls, with the exception of S. pneumoniae in exposed controls, which was detected 25% less frequently compared to nonexposed controls. Bacterial detection in induced sputum by PCR decreased 7% for exposed compared to nonexposed cases. For every additional 1 mL of blood culture specimen collected, microbial yield increased 0.51% (95% confidence interval, 0.47%-0.54%), from 2% when volume was ≤1 mL to approximately 6% for ≥3 mL. Conclusions.: Antibiotic exposure and blood culture volume affect detection of bacterial pathogens in children with pneumonia and should be accounted for in studies of etiology and in clinical management.

Background.: Lack of a gold standard for identifying bacterial and viral etiologies of pneumonia has limited evaluation of C-reactive protein (CRP) for identifying bacterial pneumonia. We evaluated the sensitivity and specificity of CRP for identifying bacterial vs respiratory syncytial virus (RSV) pneumonia in the Pneumonia Etiology Research for Child Health (PERCH) multicenter case-control study. Methods.: We measured serum CRP levels in cases with World Health Organization-defined severe or very severe pneumonia and a subset of community controls. We evaluated the sensitivity and specificity of elevated CRP for "confirmed" bacterial pneumonia (positive blood culture or positive lung aspirate or pleural fluid culture or polymerase chain reaction [PCR]) compared to "RSV pneumonia" (nasopharyngeal/oropharyngeal or induced sputum PCR-positive without confirmed/suspected bacterial pneumonia). Receiver operating characteristic (ROC) curves were constructed to assess the performance of elevated CRP in distinguishing these cases. Results.: Among 601 human immunodeficiency virus (HIV)-negative tested controls, 3% had CRP ≥40 mg/L. Among 119 HIV-negative cases with confirmed bacterial pneumonia, 77% had CRP ≥40 mg/L compared with 17% of 556 RSV pneumonia cases. The ROC analysis produced an area under the curve of 0.87, indicating very good discrimination; a cut-point of 37.1 mg/L best discriminated confirmed bacterial pneumonia (sensitivity 77%) from RSV pneumonia (specificity 82%). CRP ≥100 mg/L substantially improved specificity over CRP ≥40 mg/L, though at a loss to sensitivity. Conclusions.: Elevated CRP was positively associated with confirmed bacterial pneumonia and negatively associated with RSV pneumonia in PERCH. CRP may be useful for distinguishing bacterial from RSV-associated pneumonia, although its role in discriminating against other respiratory viral-associated pneumonia needs further study.

Biological safety cabinets (BSCs) are the primary means of containment used in laboratories worldwide for the safe handling of infectious microorganisms. They provide protection to the laboratory worker and the surrounding environment from pathogens. To ensure the correct functioning of BSCs, they need to be properly maintained beyond the daily care routines of the laboratory. This involves annual maintenance and certification by a qualified technician in accordance to the NSF/American National Standards Institute 49-2014 Biosafety Cabinetry: Design, Construction, Performance, and Field Certification. Service programs can be direct from the manufacturer or through third-party service companies, but in many instances, technicians are not accredited by international bodies, and these services are expensive. This means that a large number of BSCs may not be operating in a safe manner. In this article, we discuss our approach to addressing the lack of trained and qualified personnel in Thailand who can install, maintain, and certify BSCs in a cost-effective and practical manner. We initiated a program to create both local and regional capacity for repair, maintenance, and certification of BSCs and share our experiences with the reader.

Community-acquired bloodstream infections cause substantial morbidity and mortality worldwide but microbiology capacity and surveillance limitations have challenged good descriptions of pathogen distribution in many regions, including Southeast Asia. Active surveillance for bloodstream infections has been conducted in two rural Thailand provinces for >7 years. Blood specimens were divided into two culture bottles: one optimized for aerobic growth (F bottle) and a second for enhanced growth of mycobacteria (MB bottle), and processed used the BactT/ALERT 3D(R) system. Because routine use of MB culture bottles is resource intensive (expensive and prolonged incubation), we assessed the added yield of MB bottles by comparing the proportion of pathogens detected by MB vs. F bottles from 2005 - 2012. Of 63,066 blood cultures, 7,296(12%) were positive for at least one pathogen, the most common pathogens were Escherichia coli (28%), Burkholderia pseudomallei (11%), Klebsiella pneumoniae (9%) and Staphylococcus aureus (6%). Two bottles improved yield overall, but added yield attributable to the MB bottles was limited to a few pathogens. In addition to mycobacteria and some fungi, MB bottles improved B. pseudomallei detection (MB 27% vs. F 8%; p-value < 0.0001) with added benefit if therapy was initiated prior to the blood draw culture. Targeted use of MB bottles is warranted for patients at risk for mycobacterial and fungal infections, as well as B. pseudomallei, a common cause of septicemia in Thailand.

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.

BACKGROUND: Streptococcus pneumoniae is an important cause of morbidity and mortality in Southeast Asia, but regional data is limited. Updated burden estimates are critical as pneumococcal conjugate vaccine (PCV) is highly effective, but not yet included in the Expanded Program on Immunization of Thailand or neighboring countries. METHODS: We implemented automated blood culture systems in two rural Thailand provinces as part of population-based surveillance for bacteremia. Blood cultures were collected from hospitalized patients as clinically indicated. RESULTS: From May 2005- March 2010, 196 cases of pneumococcal bacteremia were confirmed in hospitalized patients. Of these, 57% had clinical pneumonia, 20% required mechanical ventilation, and 23% (n = 46) died. Antibiotic use before blood culture was confirmed in 25% of those with blood culture. Annual incidence of hospitalized pneumococcal bacteremia was 3.6 per 100,000 person-years; rates were higher among children aged <5 years at 11.7 and adults ≥65 years at 14.2, and highest among infants <1 year at 33.8. The median monthly case count was higher during December-March compared to the rest of the year 6.0 vs. 1.0 (p<0.001). The most common serotypes were 23F (16%) and 14 (14%); 61% (74% in patients <5 years) were serotypes in the 10-valent PCV (PCV 10) and 82% (92% in <5 years) in PCV 13. All isolates were sensitive to penicillin, but non-susceptibility was high for co-trimoxazole (57%), erythromycin (30%), and clindamycin (20%). CONCLUSIONS: We demonstrated a high pneumococcal bacteremia burden, yet underestimated incidence because we captured only hospitalized cases, and because pre-culture antibiotics were frequently used. Our findings together with prior research indicate that PCV would likely have high serotype coverage in Thailand. These findings will complement ongoing cost effectiveness analyses and support vaccine policy evaluation in Thailand and the region.

The purpose of this investigation was to enhance the detection of pneumococcal bacteremia cases using the Binax NOW(R) immunochromatographic test (ICT) on blood culture broth as part of surveillance in two rural Thailand provinces. Blood cultures were collected as clinically indicated from hospitalized patients. ICT was performed on broth from culture bottles flagged as positive by BactT/ALERT(R) (alarm-positive) but which failed to grow organisms on subculture. During the period May 2005-June 2007, ICT was positive on 43 (24%) of 182 alarm-positive blood cultures with no growth on subculture. Compared to pneumococcal bacteremia cases confirmed by culture, cases detected only by ICT had a longer median time from culture collection to incubation and a longer median time from alarm positivity to subculture, and were more likely to be from patients pretreated with antibiotics. In a subsequent surveillance period (July 2007-December 2009), ICT continued to detect additional pneumococcal cases, but in a lower proportion of samples (7 of 221, 3.2%). Recently, as part of a separate study, ICT applied to uninoculated blood culture broth produced weak-positive results, mandating caution if testing broth from patient blood cultures. The antigen testing of blood culture broth appears to enhance the detection of pneumococcal bacteremia, but a controlled evaluation is needed.

Burkholderia pseudomallei, the causative agent of melioidosis, is endemic in northeastern Thailand. Population-based disease burden estimates are lacking and limited data on melioidosis exist from other regions of the country. Using active, population-based surveillance, we measured the incidence of bacteremic melioidosis in the provinces of Sa Kaeo (eastern Thailand) and Nakhon Phanom (northeastern Thailand) during 2006-2008. The average annual incidence in Sa Kaeo and Nakhon Phanom per 100,000 persons was 4.9 (95% confidence interval [CI] = 3.9-6.1) and 14.9 (95% CI = 13.3-16.6). The respective population mortality rates were 1.9 (95% CI = 1.3-2.8) and 4.4 (95% CI = 3.6-5.3) per 100,000. The case-fatality proportion was 36% among those with known outcome. Our findings document a high incidence and case fatality proportion of bacteremic melioidosis in Thailand, including a region not traditionally considered highly endemic, and have potential implications for clinical management and health policy.

No studies have quantified the impact of pre-culture antibiotic use on the recovery of individual blood-borne pathogens or on population-level incidence estimates for Streptococcus pneumoniae. We conducted bloodstream infection surveillance in Thailand during November 2005-June 2008. Pre-culture antibiotic use was assessed by reported use and by serum antimicrobial activity. Of 35,639 patient blood cultures, 27% had reported pre-culture antibiotic use and 24% (of 24,538 tested) had serum antimicrobial activity. Pathogen isolation was half as common in patients with versus without antibiotic use; S. pneumoniae isolation was 4- to 9-fold less common (0.09% versus 0.37% by reported antibiotic use; 0.05% versus 0.45% by serum antimicrobial activity, P < 0.01). Pre-culture antibiotic use by serum antimicrobial activity reduced pneumococcal bacteremia incidence by 32% overall and 39% in children < 5 years of age. Our findings highlight the limitations of culture-based detection methods to estimate invasive pneumococcal disease incidence in settings where pre-culture antibiotic use is common.