Forest malaria and prospects for anti-malarial chemoprophylaxis among forest goers: findings from a qualitative study in Thailand.

BACKGROUND: Across the Greater Mekong Subregion, malaria remains a dangerous infectious disease, particularly for people who visit forested areas where residual transmission continues. Because vector control measures offer incomplete protection to forest goers, chemoprophylaxis has been suggested as a potential supplementary measure for malaria prevention and control. To implement prophylaxis effectively, additional information is needed to understand forest goers' activities and their willingness to use malaria prevention measures, including prophylaxis, and how it could be delivered in communities. Drawing on in-depth interviews with forest goers and stakeholders, this article examines the potential acceptability and implementation challenges of malaria prophylaxis for forest goers in northeast Thailand. METHODS: In-depth interviews were conducted with forest goers (n = 11) and stakeholders (n = 16) including healthcare workers, community leaders, and policymakers. Interviews were audio-recorded, transcribed and coded using NVivo, employing an inductive and deductive approach, for thematic analysis. RESULTS: Forest goers were well aware of their (elevated) malaria risk and reported seeking care for malaria from local health care providers. Forest goers and community members have a close relationship with the forest but are not a homogenous group: their place and time-at-risk varied according to their activities and length of stay in the forest. Among stakeholders, the choice and cost of anti-malarial prophylactic regimen-its efficacy, length and complexity, number of tablets, potential side effects, and long-term impact on users-were key considerations for its feasibility. They also expressed concern about adherence to the preventive therapy and potential difficulty treating malaria patients with the same regimen. Prophylaxis was considered a low priority in areas with perceived accessible health system and approaching malaria elimination. CONCLUSIONS: In the context of multi-drug resistance, there are several considerations for implementing malaria prophylaxis: the need to target forest goers who are at-risk with a clear period of exposure, to ensure continued use of vector control measures and adherence to prophylactic anti-malarials, and to adopt an evidence-based approach to determine an appropriate regimen. Beyond addressing current intervention challenges and managing malaria incidence in low-transmission setting, it is crucial to keep malaria services available and accessible at the village level especially in areas home to highly mobile populations.

Pneumococcal pneumonia prevalence among adults with severe acute respiratory illness in Thailand - comparison of Bayesian latent class modeling and conventional analysis.

BACKGROUND: Determining the etiology of pneumonia is essential to guide public health interventions. Diagnostic test results, including from polymerase chain reaction (PCR) assays of upper respiratory tract specimens, have been used to estimate prevalence of pneumococcal pneumonia. However limitations in test sensitivity and specificity and the specimen types available make establishing a definitive diagnosis challenging. Prevalence estimates for pneumococcal pneumonia could be biased in the absence of a true gold standard reference test for detecting Streptococcus pneumoniae. METHODS: We conducted a case control study to identify etiologies of community acquired pneumonia (CAP) from April 2014 through August 2015 in Thailand. We estimated the prevalence of pneumococcal pneumonia among adults hospitalized for CAP using Bayesian latent class models (BLCMs) incorporating results of real-time polymerase chain reaction (qPCR) testing of upper respiratory tract specimens and a urine antigen test (UAT) from cases and controls. We compared the prevalence estimate to conventional analyses using only UAT as a reference test. RESULTS: The estimated prevalence of pneumococcal pneumonia was 8% (95% CI: 5-11%) by conventional analyses. By BLCM, we estimated the prevalence to be 10% (95% CrI: 7-16%) using binary qPCR and UAT results, and 11% (95% CrI: 7-17%) using binary UAT results and qPCR cycle threshold (Ct) values. CONCLUSIONS: BLCM suggests a > 25% higher prevalence of pneumococcal pneumonia than estimated by a conventional approach assuming UAT as a gold standard reference test. Higher quantities of pneumococcal DNA in the upper respiratory tract were associated with pneumococcal pneumonia in adults but the addition of a second specific pneumococcal test was required to accurately estimate disease status and prevalence. By incorporating the inherent uncertainty of diagnostic tests, BLCM can obtain more reliable estimates of disease status and improve understanding of underlying etiology.

Evaluation of Pneumococcal Load in Blood by Polymerase Chain Reaction for the Diagnosis of Pneumococcal Pneumonia in Young Children in the PERCH Study.

BACKGROUND.: Detection of pneumococcus by lytA polymerase chain reaction (PCR) in blood had poor diagnostic accuracy for diagnosing pneumococcal pneumonia in children in 9 African and Asian sites. We assessed the value of blood lytA quantification in diagnosing pneumococcal pneumonia. METHODS.: The Pneumonia Etiology Research for Child Health (PERCH) case-control study tested whole blood by PCR for pneumococcus in children aged 1-59 months hospitalized with signs of pneumonia and in age-frequency matched community controls. The distribution of load among PCR-positive participants was compared between microbiologically confirmed pneumococcal pneumonia (MCPP) cases, cases confirmed for nonpneumococcal pathogens, nonconfirmed cases, and controls. Receiver operating characteristic analyses determined the "optimal threshold" that distinguished MCPP cases from controls. RESULTS.: Load was available for 290 of 291 cases with pneumococcal PCR detected in blood and 273 of 273 controls. Load was higher in MCPP cases than controls (median, 4.0 × 103 vs 0.19 × 103 copies/mL), but overlapped substantially (range, 0.16-989.9 × 103 copies/mL and 0.01-551.9 × 103 copies/mL, respectively). The proportion with high load (≥2.2 log10 copies/mL) was 62.5% among MCPP cases, 4.3% among nonconfirmed cases, 9.3% among cases confirmed for a nonpneumococcal pathogen, and 3.1% among controls. Pneumococcal load in blood was not associated with respiratory tract illness in controls (P = .32). High blood pneumococcal load was associated with alveolar consolidation on chest radiograph in nonconfirmed cases, and with high (>6.9 log10 copies/mL) nasopharyngeal/oropharyngeal load and C-reactive protein ≥40 mg/L (both P < .01) in nonconfirmed cases but not controls. CONCLUSIONS.: Quantitative pneumococcal PCR in blood has limited diagnostic utility for identifying pneumococcal pneumonia in individual children, but may be informative in epidemiological studies.

An outbreak of Paederus dermatitis in Thai military personnel.

An outbreak of Paederus dermatitis in Thai military personnel in 2007 was reported. Approximately ninety-one percent ofmilitary personnel who worked in a battalion located in Bangkok experienced Paederus dermatitis in April-May 2007. The most common clinical manifestations were blisters and erythematous rash. The most affected areas were head, neck, back and groin. "Kissing lesions" were seen in 17.3% of cases and 23.5% had multiple lesions. Compared with other reports, we found a high incidence of lesions in unexposed body parts. This disease should be recognized as a differential diagnosis especially in tropical countries. Awareness of the condition and its clinical features will aid early diagnosis and prompt treatment.

Prevalence and risk factors for Chlamydia trachomatis infection among young Thai men in 2008-2009.

BACKGROUND: Asymptomatic Chlamydia trachomatis (CT) infection and other sexually transmitted infections in men potentially contribute significantly in sustaining the spread of the infection. To describe the distribution and related sexual behaviors, we conducted a cross-sectional study among young Thai men using a (1:30) systematic sampling of all newly inducted military conscripts in Thailand. METHODS: In November 2008 and May 2009, participants' urine and serum samples were tested for CT and Neisseria gonorrhoeae, using a multiplex polymerase chain reaction technique, and serologic testing for Treponema pallidum and HIV-1 was done. Information on demographic data and risk behaviors was obtained by a self-administered questionnaire. RESULTS: The overall prevalence rates of CT, N. gonorrhoeae, HIV-1, and syphilis infection were 7.9%, 0.9%, 0.5%, 0.05%, respectively. The risk factors for CT infection were living in the upper north region (adjusted rate ratios [95% confidence interval], 2.13 [1.39-3.26]), having had 4 or more sexual partners (2.14 [1.48-3.09]), graduation from a vocational school (1.66 [1.14-2.41]), inconsistent condom use (1.48 [1.05-2.08]), unemployment (1.82 [1.06-3.12]), and age 21 years or younger (1.63 [1.01-2.63]). CONCLUSIONS: The prevalence of CT infection among young male military conscripts was high, especially among men from upper northern Thailand. Multiple sexual partners, graduation from a vocational school, inconsistent condom use, unemployment before the military induction, and younger age were independently associated with the CT infection among young Thai men. These data will be useful to develop more effective public health interventions to prevent, detect, and treat sexually transmitted infections among young men in Thailand.

Melioidosis in animals, Thailand, 2006-2010.

We retrospectively estimated the incidence of culture-proven melioidosis in animals in Thailand during 2006-2010. The highest incidence was in goats (1.63/100,000/year), followed by incidence in pigs and cattle. The estimated incidence of melioidosis in humans in a given region paralleled that of melioidosis in goats.

Hospitalized Bacteremic Melioidosis in Rural Thailand: 2009-2013.

Melioidosis incidence and mortality have reportedly been increasing in endemic areas of Thailand, but little population-based data on culture-confirmed Burkholderia pseudomallei infections exist. We provide updated estimates of melioidosis bacteremia incidence and in-hospital mortality rate using integration of two population-based surveillance databases in Nakhon Phanom, Thailand, since automated blood culture became available in 2005. From 2009 to 2013, 564 hospitalized bacteremic melioidosis patients were identified. The annual incidence of bacteremic melioidosis ranged from 14 to 17 per 100,000 persons, and average population mortality rate was 2 per 100,000 persons per year. In-hospital mortality rate declined nonsignificantly from 15% (15/102) to 13% (15/118). Of 313 (56%) bacteremic melioidosis patients who met criteria for acute lower respiratory infection and were included in the hospital-based pneumonia surveillance system, 65% (202/313) had a chest radiograph performed within 48 hours of admission; 46% (92/202) showed radiographic evidence of pneumonia. Annual incidence of bacteremic melioidosis with pneumonia was 2.4 per 100,000 persons (95% confidence intervals; 1.9-2.9). In-hospital death was more likely among bacteremic melioidosis patients with pneumonia (34%; 20/59) compared with non-pneumonia patients (18%; 59/321) (P-value = 0.007). The overall mortality could have been as high as 46% (257/564) if patients with poor clinical condition at the time of discharge had died. The continued high incidence of bacteremic melioidosis, pneumonia, and deaths in an endemic area highlights the need for early diagnosis and treatment and additional interventions for the prevention and control for melioidosis.

Epidemiology and antimicrobial resistance of invasive non-typhoidal Salmonellosis in rural Thailand from 2006-2014.

INTRODUCTION: Invasive salmonellosis is a common cause of bloodstream infection in Southeast Asia. Limited epidemiologic and antimicrobial resistance data are available from the region. METHODS: Blood cultures performed in all 20 hospitals in the northeastern province of Nakhon Phanom (NP) and eastern province of Sa Kaeo (SK), Thailand were captured in a bloodstream infection surveillance system. Cultures were performed as clinically indicated in hospitalized patients; patients with multiple positive cultures had only the first included. Bottles were incubated using the BacT/Alert system (bioMérieux, Thailand) and isolates were identified using standard microbiological techniques; all Salmonella isolates were classified to at least the serogroup level. Antimicrobial resistance was assessed using disk diffusion. RESULTS: Salmonella was the fifth most common pathogen identified in 147,535 cultures with 525 cases (211 in Nakhon Phanom (NP) and 314 in Sa Kaeo (SK)). The overall adjusted iNTS incidence rate in NP was 4.0 cases/100,000 person-years (95% CI 3.5-4.5) and in SK 6.4 cases/100,000 person-years (95% CI 5.7-7.1; p = 0.001). The most common serogroups were C (39.4%), D (35.0%) and B (9.9%). Serogroup D predominated in NP (103/211) with 59.2% of this serogroup being Salmonella serovar Enteritidis. Serogroup C predominated in SK (166/314) with 84.3% of this serogroup being Salmonella serovar Choleraesuis. Antibiotic resistance was 68.2% (343/503) for ampicillin, 1.2% (6/482) for ciprofloxacin (or 58.1% (280/482) if both intermediate and resistant phenotypes are considered), 17.0% (87/512) for trimethoprim-sulfamethoxazole, and 12.2% (59/484) for third-generation cephalosporins (cefotaxime or ceftazidime). Multidrug resistance was seen in 99/516 isolates (19.2%). CONCLUSIONS: The NTS isolates causing bloodstream infections in rural Thailand are commonly resistant to ampicillin, cefotaxime, and TMP-SMX. Observed differences between NP and SK indicate that serogroup distribution and antibiotic resistance may substantially differ throughout Thailand and the region.

Increasing incidence of hospital-acquired and healthcare-associated bacteremia in northeast Thailand: a multicenter surveillance study.

BACKGROUND: Little is known about the epidemiology of nosocomial bloodstream infections in public hospitals in developing countries. We evaluated trends in incidence of hospital-acquired bacteremia (HAB) and healthcare-associated bacteremia (HCAB) and associated mortality in a developing country using routinely available databases. METHODS: Information from the microbiology and hospital databases of 10 provincial hospitals in northeast Thailand was linked with the national death registry for 2004-2010. Bacteremia was considered hospital-acquired if detected after the first two days of hospital admission, and healthcare-associated if detected within two days of hospital admission with a prior inpatient episode in the preceding 30 days. RESULTS: A total of 3,424 patients out of 1,069,443 at risk developed HAB and 2,184 out of 119,286 at risk had HCAB. Of these 1,559 (45.5%) and 913 (41.8%) died within 30 days, respectively. Between 2004 and 2010, the incidence rate of HAB increased from 0.6 to 0.8 per 1,000 patient-days at risk (p<0.001), and the cumulative incidence of HCAB increased from 1.2 to 2.0 per 100 readmissions (p<0.001). The most common causes of HAB were Acinetobacter spp. (16.2%), Klebsiella pneumoniae (13.9%), and Staphylococcus aureus (13.9%), while those of HCAB were Escherichia coli (26.3%), S. aureus (14.0%), and K. pneumoniae (9.7%). There was an overall increase over time in the proportions of ESBL-producing E. coli causing HAB and HCAB. CONCLUSIONS: This study demonstrates a high and increasing incidence of HAB and HCAB in provincial hospitals in northeast Thailand, increasing proportions of ESBL-producing isolates, and very high associated mortality.

Epidemiology, microbiology and mortality associated with community-acquired bacteremia in northeast Thailand: a multicenter surveillance study.

BACKGROUND: National statistics in developing countries are likely to underestimate deaths due to bacterial infections. Here, we calculated mortality associated with community-acquired bacteremia (CAB) in a developing country using routinely available databases. METHODS/PRINCIPAL FINDINGS: Information was obtained from the microbiology and hospital database of 10 provincial hospitals in northeast Thailand, and compared with the national death registry from the Ministry of Interior, Thailand for the period between 2004 and 2010. CAB was defined in patients who had pathogenic organisms isolated from blood taken within 2 days of hospital admission without a prior inpatient episode in the preceding 30 days. A total of 15,251 CAB patients identified, of which 5,722 (37.5%) died within 30 days of admission. The incidence rate of CAB between 2004 and 2010 increased from 16.7 to 38.1 per 100,000 people per year, and the mortality rate associated with CAB increased from 6.9 to 13.7 per 100,000 people per year. In 2010, the mortality rate associated with CAB was lower than that from respiratory tract infection, but higher than HIV disease or tuberculosis. The most common causes of CAB were Escherichia coli (23.1%), Burkholderia pseudomallei (19.3%), and Staphylococcus aureus (8.2%). There was an increase in the proportion of Extended-Spectrum Beta-Lactamases (ESBL) producing E. coli and Klebsiella pneumoniae over time. CONCLUSIONS: This study has demonstrated that national statistics on causes of death in developing countries could be improved by integrating information from readily available databases. CAB is neglected as an important cause of death, and specific prevention and intervention is urgently required to reduce its incidence and mortality.

Prevalence and risk factors for hepatitis C virus infection among young Thai men.

Epidemiologic studies of hepatitis C virus (HCV) infection are unusual in developing countries, especially Thailand. We evaluated the prevalence and risk factors for HCV among military conscripts, including a sample of 5,246 men (1:30 sample), and human immunodeficiency virus (HIV)-1 positive men (N = 500) between 2005 and 2008. The HCV prevalence was 2.2% in the sampled group and 8.4% in HIV-1 sero-positives. Among the sampled group, HIV-1 infection, injection drug use (IDU) history, and unsafe injections were associated with HCV infection; adjusted prevalence rate ratios [RRs; 95% confidence intervals (CIs)] were 3.7 (1.04-12.77), 1.9 (1.04-3.54), and 1.8 (1.02-3.11), respectively. Among HIV-1 sero-positives, an IDU history and residence in southern Thailand were associated with HCV prevalence; adjusted RRs (95% CIs) were 3.5 (1.71-7.24) and 2.6 (1.18-5.61), respectively. Public health measures to prevent HCV in Thailand should focus on reducing injection drug use and other exposures to unsafe injections among young Thai men.