Workshops advocating ASEAN Vaccine Security and Self-Reliance (AVSSR): A regional initiative.

The concept of ASEAN Vaccine Security and Self-Reliance (AVSSR) has recently been advocated for by the National Vaccine Institute (NVI), a public organization of Thailand, through two workshops in 2014 and 2015 organized in cooperation with the World Health Organization (WHO) for the ASEAN Collaboration Initiatives for Regional Vaccine Security and Self-Reliance (VSSR). In both workshops relevant policy makers, Expanded Programme on Immunization (EPI) managers, and experts from government and partner agencies involved in the vaccine life cycle actively participated. A paradigm shift in leveraging the initiatives of VSSR from national to regional levels was noted and reiterated. The first workshop's objective was to understand the perspectives and identify the needs of ASEAN countries regarding vaccine security, and to list potential areas for further collaboration. The existing vaccine-related capacities, collaborations, and networks in ASEAN were discussed based on findings from a pre-workshop, self-administered questionnaire survey. The workshop ended with four key areas unanimously recommended for regional collaboration strengthening: (1) system development for vaccine security; (2) human resource development; (3) ASEAN price policy for vaccine (APPV) and pooled procurement; and (4) communication and coordination. A call for immediate action was made, prompting the second workshop to focus only on "communication and coordination" to identify concrete, actionable collaborative models for effective communication and coordination. At the second workshop, a five-year Communication and Coordination Action Plan (CCAP) was developed to foster long-term AVSSR. The AVSSR's ultimate goal is to avoid incidental vaccine shortage and ensure sufficient supply of affordable, quality vaccines for normal and urgent situations both at the national and ASEAN-wide levels. To date, collaboration for AVSSR is being strengthened according to the ASEAN post-2015 Health Development Agenda and its collaborative framework among concerned countries and development partners. Nevertheless, to achieve the goal, integration of multiple strategies based upon strong policy commitment and uninterrupted engagement among relevant partners are required.

Economic Evaluation and Budget Impact Analysis of Vaccination against Haemophilus influenzae Type b Infection in Thailand.

Current study aimed to estimate clinical and economic outcomes of providing the Haemophilus influenzae type b (Hib) vaccination as a national vaccine immunization program in Thailand. A decision tree combined with Markov model was developed to simulate relevant costs and health outcomes covering lifetime horizon in societal and health care payer perspectives. This analysis considered children aged under 5 years old whom preventive vaccine of Hib infection are indicated. Two combined Hib vaccination schedules were considered: three-dose series (3 + 0) and three-dose series plus a booster does (3 + 1) compared with no vaccination. Budget impact analysis was also performed under Thai government perspective. The outcomes were reported as Hib-infected cases averted and incremental cost-effectiveness ratios (ICERs) in 2014 Thai baht (THB) ($) per quality-adjusted life year (QALY) gained. In base-case scenario, the model estimates that 3,960 infected cases, 59 disability cases, and 97 deaths can be prevented by national Hib vaccination program. The ICER for 3 + 0 schedule was THB 1,099 ($34) per QALY gained under societal perspective. The model was sensitive to pneumonia incidence among aged under 5 years old and direct non-medical care cost per episode of Hib pneumonia. Hib vaccination is very cost-effective in the Thai context. The budget impact analysis showed that Thai government needed to invest an additional budget of 110 ($3.4) million to implement Hib vaccination program. Policy makers should consider our findings for adopting this vaccine into national immunization program.

Do Thai Physicians Recommend Seasonal Influenza Vaccines to Pregnant Women? A Cross-Sectional Survey of Physicians' Perspectives and Practices in Thailand.

BACKGROUND: Physicians play a major role in influencing acceptance and uptake of vaccines. However, little is known about physicians' perspectives on influenza vaccination of pregnant women in Thailand, for whom vaccine coverage is estimated at <1%. METHOD: In 2013, a self-administered questionnaire on physicians' perceptions, attitudes and practices related to influenza vaccination for pregnant women was distributed to 1,134 hospitals with an antenatal care clinic (ANC) in Thailand. At each hospital, one physician working at the ANC completed the survey. Predictors of routine recommendation of influenza vaccine were analyzed utilizing log-binomial regression. RESULTS: A total of 580 (51%) complete responses were received from physicians practicing at ANCs. A favorable attitude towards vaccination was expressed by 436 (75%) physicians, however only 142 (25%) reported routinely recommending influenza vaccine to pregnant women in their current practice. Physicians were more likely to recommend influenza vaccine routinely when they had more than three years of practice (prevalence ratio [PR] 1.9, 95% CI 1.2-2.3), had treated pregnant women for influenza (PR 1.8, 95% CI 1.3-2.7), perceived the influenza vaccine to be effective (moderate level: PR 1.6, 95% CI 1.1-2.4; high level: PR 1.9, 95% CI 1.3-2.9) and were aware of the Ministry of Public Health's (MOPH) recommendation of influenza vaccination in pregnancy (PR 1.3, 95% CI 1.1-1.7). Vaccine not being available, perception that policy was ambiguous and lack of awareness of MOPH recommendations were the most commonly cited barriers to routine recommendation of influenza vaccine. CONCLUSION: Despite a national policy to vaccinate pregnant women for influenza, only 25% of Thai physicians working in ANCs routinely recommend vaccination. Strategies are needed to increase vaccine availability and free vaccine services, address clinician concerns over vaccine effectiveness and expand healthcare provider awareness of MOPH recommendations.

What criteria do decision makers in Thailand use to set priorities for vaccine introduction?

BACKGROUND: There is a need to identify rational criteria and set priorities for vaccines. In Thailand, many licensed vaccines are being considering for introduction into the Expanded Program on Immunization; thus, the government has to make decisions about which vaccines should be adopted. This study aimed to set priorities for new vaccines and to facilitate decision analysis. METHODS: We used a best-worst scaling study for rank-ordering of vaccines. The candidate vaccines were determined by a set of criteria, including burden of disease, target age group, budget impact, side effect, effectiveness, severity of disease, and cost of vaccine. The criteria were identified from a literature review and by in-depth, open-ended interviews with experts. The priority-setting model was conducted among three groups of stakeholders, including policy makers, healthcare professionals and healthcare administrators. The vaccine data were mapped and then calculated for the probability of selection. RESULTS: From the candidate vaccines, the probability of hepatitis B vaccine being selected by all respondents (96.67 %) was ranked first. This was followed, respectively, by pneumococcal conjugate vaccine-13 (95.09 %) and Haemophilus influenzae type b vaccine (90.87 %). The three groups of stakeholders (policy makers, healthcare professionals and healthcare administrators) showed the same ranking trends. Most severe disease, high fever rate and high disease burden showed the highest coefficients for criterion levels being selected by all respondents. This result can be implied that a vaccine which can prevent most severe disease with high disease burden and has low safety has a greater chance of being selected by respondents in this study. CONCLUSIONS: The priority setting of vaccines through a multiple-criteria approach could contribute to transparency and accountability in the decision-making process. This is a step forward in the development of an evidence-based approach that meets the need of developing country. The methodology is generalizable but its application to another country would require the criteria as relevant to that country.

Knowledge, attitudes and beliefs related to seasonal influenza vaccine among pregnant women in Thailand.

BACKGROUND: In 2009, Thailand recommended pregnant women be prioritized for influenza vaccination. Vaccine uptake among Thai pregnant women is lower than other high-risk groups. METHODS: During December 2012-April 2013, we conducted a cross-sectional survey of a convenience sample of Thai pregnant women aged ≥ 15 years attending antenatal clinics at public hospitals in 8 of 77 provinces. A self-administered questionnaire covered knowledge, attitudes, and beliefs related to influenza vaccination using the Health Belief Model. We examined factors associated with willingness to be vaccinated using log-binomial regression models. RESULTS: The survey was completed by 1031 (96%) of 1072 pregnant women approached. A total of 627 (61%) women had heard about influenza vaccine and were included in the analysis, of whom 262 (42%) were willing to be vaccinated, 155 (25%) had received a healthcare provider recommendation for influenza vaccination and 25 (4%) had received the influenza vaccine during the current pregnancy. In unadjusted models, high levels of perceptions of susceptibility (prevalence ratio [PR] 1.5, 95% CI 1.2-2.0), high levels of belief in the benefits of vaccination (PR 2.3, 95% CI 1.7-3.1), moderate (PR 1.7, 95% CI 1.2-2.3) and high (PR 3.4, 95% CI 2.6-4.5) levels of encouragement by others to be vaccinated (i.e., cues to action) were positively associated with willingness to be vaccinated. Moderate (PR 0.5, 95% CI 0.4-0.7) and high levels of (PR 0.5, 95% CI 0.4-0.8) perceived barriers were negatively associated with willingness to be vaccinated. In the final adjusted model, only moderate (PR 1.5, 95% CI 1.1-2.0) and high levels of cues to action (PR 2.7, 95% CI 2.0-3.6) were statistically associated with willingness to be vaccinated. CONCLUSION: Cues to action were associated with willingness to be vaccinated and can be used to inform communication strategies during the vaccine campaign to increase influenza vaccination among Thai pregnant women.

Incidence of Pneumococcal Pneumonia Among Adults in Rural Thailand, 2006-2011: Implications for Pneumococcal Vaccine Considerations.

The incidence of pneumococcal pneumonia among adults is a key driver for the cost-effectiveness of pneumococcal conjugate vaccine used among children. We sought to obtain more accurate incidence estimates among adults by including results of pneumococcal urine antigen testing (UAT) from population-based pneumonia surveillance in two Thai provinces. Active surveillance from 2006 to 2011 identified acute lower respiratory infection (ALRI)-related hospital admissions. Adult cases of pneumococcal pneumonia were defined as hospitalized ALRI patients aged ≥ 18 years with isolation of Streptococcus pneumoniae from blood or with positive UAT. Among 39,525 adult ALRI patients, we identified 481 pneumococcal pneumonia cases (105 by blood culture, 376 by UAT only). Estimated incidence of pneumococcal pneumonia hospitalizations was 30.5 cases per 100,000 persons per year (2.2 and 28.3 cases per 100,000 persons per year by blood culture and UAT, respectively). Incidence varied between 22.7 in 2007 and 43.5 in 2010, and increased with age to over 150 per 100,000 persons per year among persons aged ≥ 70 years. Viral coinfections including influenza A/B, respiratory syncytial virus (RSV), and adenovirus occurred in 11% (44/409) of pneumococcal pneumonia cases tested. Use of UAT to identify cases of pneumococcal pneumonia among adults in rural Thailand substantially increases estimates of pneumococcal pneumonia burden, thereby informing cost-effectiveness analyses and vaccine policy decisions.

Seasonal influenza vaccine coverage among high-risk populations in Thailand, 2010-2012.

BACKGROUND: The Advisory Committee on Immunization Practice of Thailand prioritizes seasonal influenza vaccinations for populations who are at highest risk for serious complications (pregnant women, children 6 months-2 years, persons ≥65 years, persons with chronic diseases, obese persons), and healthcare personnel and poultry cullers. The Thailand government purchases seasonal influenza vaccine for these groups. We assessed vaccination coverage among high-risk groups in Thailand from 2010 to 2012. METHODS: National records on persons who received publicly purchased vaccines from 2010 to 2012 were analyzed by high-risk category. Denominator data from multiple sources were compared to calculate coverage. Vaccine coverage was defined as the proportion of individuals in each category who received the vaccine. Vaccine wastage was defined as the proportion of publicly purchased vaccines that were not used. RESULTS: From 2010 to 2012, 8.18 million influenza vaccines were publicly purchased (range, 2.37-3.29 million doses/year), and vaccine purchases increased 39% over these years. Vaccine wastage was 9.5%. Approximately 5.7 million (77%) vaccine doses were administered to persons ≥65 years and persons with chronic diseases, 1.4 million (19%) to healthcare personnel/poultry cullers, 82,570 (1.1%) to children 6 months-2 years, 78,885 (1.1%) to obese persons, 26,481 (0.4%) to mentally disabled persons, and 17,787 (0.2%) to pregnant women. Between 2010 and 2012, coverage increased among persons with chronic diseases (8.6% versus 14%; p<0.01) and persons ≥65 years (12%, versus 20%; p<0.01); however, coverage decreased for mentally disabled persons (6.1% versus 4.9%; p<0.01), children 6 months-2 years (2.3% versus 0.9%; p<0.01), pregnant women (1.1% versus 0.9%; p<0.01), and obese persons (0.2% versus 0.1%; p<0.01). CONCLUSIONS: From 2010 to 2012, the availability of publicly purchased vaccines increased. While coverage remained low for all target groups, coverage was highest among persons ≥65 years and persons with chronic diseases. Annual coverage assessments are necessary to promote higher coverage among high-risk groups in Thailand.

Effectiveness of the 2010 and 2011 Southern Hemisphere trivalent inactivated influenza vaccines against hospitalization with influenza-associated acute respiratory infection among Thai adults aged ≥ 50 years.

BACKGROUND: Inactivated influenza vaccine (IIV) effectiveness has been evaluated among older adults in high-income countries, but data on IIV effectiveness in low- and middle-income countries remain sparse. We conducted a test-negative case-control analysis to estimate 2010 and 2011 trivalent IIV effectiveness against hospitalization with influenza-associated acute respiratory infection (ARI) among persons aged ≥ 50 years in rural Thailand. METHODS: During 2010-2011, active surveillance for ARI hospitalization was conducted in two provinces; patients were tested for influenza viruses by real-time RT-PCR. Vaccination status was obtained from vaccine registries. Case and control patients were patients with nasopharyngeal swabs positive and negative for influenza viruses, respectively. Vaccine effectiveness (VE) was estimated for the 6 months after vaccination began. Logistic regression was used to evaluate the association between case status and vaccination while adjusting for age, province, medical conditions, and time. RESULTS: During 2010-2011, there were 1545 patients with ARI, of whom 279 (18%) were influenza-positive case patients and 1266 (82%) were influenza-negative control patients. Of the 279 case patients, 247 (89%) had influenza A and 32 (11%) had influenza B. Fourteen of 279 (5%) case patients and 108 of 1266 (9%) control patients were vaccinated against influenza. The unadjusted IIV effectiveness against hospitalization with influenza-associated ARI was 43% (95% CI: 0-68%); adjusted VE was 47% (95% CI: 5-71%). CONCLUSION: The 2010 and 2011 IIVs were moderately effective against hospitalization with influenza-associated ARI among Thais aged ≥ 50 years, but IIV coverage was low. Additional efforts are warranted in Thailand to improve IIV uptake in this target group.

Seroincidence of Influenza Among HIV-infected and HIV-uninfected Men During the 2009 H1N1 Influenza Pandemic, Bangkok, Thailand.

Among 368 Thai men who have sex with men with paired serum samples collected before and during the 2009 H1N1 influenza pandemic, we determined influenza A (H1N1)pdm09 seroconversion rates (≥4-fold rise in antibody titers by hemagglutination inhibition or microneutralization assays). Overall, 66 of 232 (28%) participants seroconverted after the first year of A(H1N1)pdm09 activity, and 83 of 234 (35%) participants seroconverted after the second year. Influenza A(H1N1)pdm09 seroconversion did not differ between human immunodeficiency virus (HIV)-infected (55 of 2157 [35%]) and HIV-uninfected (71 of 2211 [34%]) participants (P = .78). Influenza A(H1N1)pdm09 seroconversion occurred in approximately one third of our Thai study population and was similar among HIV-infected and HIV-uninfected participants.

Economic analysis for evidence-based policy-making on a national immunization program: a case of rotavirus vaccine in Thailand.

Severe diarrhea caused by rotavirus is a health problem worldwide, including Thailand. The World Health Organization has recommended incorporating rotavirus vaccination into national immunization programs. This policy has been implemented in several countries, but not in Thailand where the mortality rate is not high. This leads to the question of whether it would be cost-effective to implement such a policy. The Thai National Vaccine Committee, through the Immunization Practice Subcommittee, has conducted an economic analysis. Their study aimed to estimate the costs of rotavirus diarrhea and of a rotavirus vaccination program, and the cost-effectiveness of such a program including budget impact analysis. The study was designed as an economic evaluation, employing modeling technique in both provider and societal perspectives. A birth cohort of Thai children in 2009 was used in the analysis, with a 5-year time horizon. Costs were composed of cost of the illness and the vaccination program. Outcomes were measured in the form of lives saved and DALYs averted. Both costs and outcomes were discounted at 3%. The study found the discounted number of deaths to be 7.02 and 20.52 for vaccinated and unvaccinated cohorts, respectively (13.5 deaths averted). Discounted DALYs were 263.33 and 826.57 for vaccinated and unvaccinated cohorts, respectively (563.24 DALYs averted). Costs of rotavirus diarrhea in a societal perspective were US$6.6 million and US$21.0 million for vaccinated and unvaccinated cohorts, respectively. At base case, the costs per additional death averted were US$5.1 million and US$5.7 for 2-dose and 3-dose vaccines, respectively, in a societal perspective. Costs per additional DALYs averted were US$128,063 and US$142,144, respectively. In a societal perspective, with a cost-effectiveness threshold at 1 GDP per capita per DALYs averted, vaccine prices per dose were US$4.98 and US$3.32 for 2-dose and 3-dose vaccines, respectively; in a provider perspective, they were US$2.90 and US$1.93. One-way and probabilistic sensitivity analyses were included. The budget required for vaccine purchase was calculated for all scenarios.

Influenza vaccination guidelines and vaccine sales in southeast Asia: 2008-2011.

BACKGROUND: Southeast Asia is a region with great potential for the emergence of a pandemic influenza virus. Global efforts to improve influenza surveillance in this region have documented the burden and seasonality of influenza viruses and have informed influenza prevention strategies, but little information exists about influenza vaccination guidelines and vaccine sales. METHODS: To ascertain the existence of influenza vaccine guidelines and define the scope of vaccine sales, we sent a standard three-page questionnaire to the ten member nations of the Association of Southeast Asian Nations. We also surveyed three multinational manufacturers who supply influenza vaccines in the region. RESULTS: Vaccine sales in the private sector were <1000 per 100,000 population in the 10 countries. Five countries reported purchasing vaccine for use in the public sector. In 2011, Thailand had the highest combined reported rate of vaccine sales (10,333 per 100,000). In the 10 countries combined, the rate of private sector sales during 2010-2011 (after the A(H1N1)2009pdm pandemic) exceeded 2008 pre-pandemic levels. Five countries (Indonesia, Malaysia, Singapore, Thailand and Vietnam) had guidelines for influenza vaccination but only two were consistent with global guidelines. Four recommended vaccination for health care workers, four for elderly persons, three for young children, three for persons with underlying disease, and two for pregnant women. CONCLUSIONS: The rate of vaccine sales in Southeast Asia remains low, but there was a positive impact in sales after the A(H1N1)2009pdm pandemic. Low adherence to global vaccine guidelines suggests that more work is needed in the policy arena.

Effectiveness of mouse brain-derived inactivated Japanese encephalitis vaccine in Thai National Immunization Program: a case-control study.

Mouse brain-derived, purified inactivated Japanese encephalitis vaccine (MB JEV) has been locally produced and introduced into Thai National Immunization Program (NIP) since 1990. However, MB JEV effectiveness has been concerned, since 30-40% of JE cases received JE vaccines were recently reported in two descriptive studies. Therefore, in 2010, a case-control study was designed to assess effectiveness of the MB JEV used in the NIP, among children aged 1 to <6 years. Subjects enrolled from all regions of the country, 26 cases were clinical encephalitis with laboratory-confirmed for JE IgM titer, while 103 controls had past illness free on encephalitis. For each case, four controls were enrolled from children living in the same community with the case. Individual health records of the subjects were used to verify JE immunization status. Among children aged ≥ 18 months old, the recommended age by the NIP, the effectiveness was estimated at 94.6% (95%CI, 79.6-98.6%) and adjusted effectiveness was 97.50% (95%CI, 88.60-99.50%). The study results suggest that the MB JEV used in the NIP is highly effective, even among children aged <18 months. Therefore, aggressive immunization using the MB JEV would greatly diminish disease burden.

Incorporation of private demand into cost-benefit analysis of a universal Hib vaccination program in Thailand.

Conjugate Hib vaccines are costly and Hib meningitis incidence in Thailand is relatively low comparing to western countries; a decision tree model was used for cost-benefit analysis (CBA) of a universal conjugate Hib vaccination program in Thailand. Tangible and intangible costs and benefits of the program, occurring from birth to 60 years of age from the provider and client perspectives, were included in the cost analysis. With a birth cohort of 740,109, at a cost of USD 8 million (THB 288 million), the program will potentially prevent 77 deaths, 19 cases of severe disability, 135 cases of meningitis, and 628 cases of pneumonia resulting in a net benefit of about USD 70 million to society. The program is cost-effective only if intangible benefits are included in the model.

A method for estimating vaccine-preventable pediatric influenza pneumonia hospitalizations in developing countries: Thailand as a case study.

The burden of influenza in children is increasingly appreciated; some middle-income countries are considering support for influenza vaccine programs. To support decision-making, methods to estimate the potential impact of proposed programs are needed. Using Thailand as a case-study, we present a model that uses surveillance data, published vaccine effectiveness estimates, and vaccination coverage assumptions to estimate the impact of influenza vaccination on pediatric influenza pneumonia hospitalizations. Approximately 56,000 influenza pneumonia hospitalizations occur annually among children aged <18 years in Thailand; 23,700 (41%) may be vaccine-preventable. Vaccination of 85% of Thai children aged 7 months-4 years might prevent 30% of all pediatric influenza pneumonia hospitalizations in Thailand.

The private demand for Hib vaccination in a probable low Hib disease incidence country: Thailand 2006.

This study aimed to determine the private demand for Hib vaccination in Thailand. A willingness-to-pay (WTP) survey was performed by face-to-face interviews of 662 pregnant women attending antenatal clinics in 4 regions of the country. Hypothetical incidence scenarios of Hib disease and hypothetical vaccine market scenarios were presented to the respondents. Regarding the scenarios, the respondents responded to discrete choice questions asking for their WTP for Hib vaccination for their children. Probit regression models were used to predict median WTP for Hib vaccine per child. A median WTP for Hib vaccine per child per vaccination course was estimated at THB 3800, or USD 106. Although Hib disease incidence in Thailand is probably low, high monetary value of WTP for Hib vaccine probably reflects concern among Thai people about severity of the disease and good perceptions about safety and efficacy of the vaccine.

Immunization policy development in Thailand: the role of the Advisory Committee on Immunization Practice.

The Advisory Committee on Immunization Practice (ACIP) of Thailand, established nearly 40 years ago and currently consisting of 28 experts in immunization and related fields, develops written recommendations to the Ministry of Public Health (MoPH) regarding vaccines and immunization. Through careful review of available scientific data, compiled and analyzed by Working Groups set up to examine specific topics, the ACIP makes recommendations concerning the inclusion of new vaccines into the national immunization program, target groups and ages for administration, vaccine schedules, and precautions and contraindications. This paper includes a description of the composition of the ACIP; the process that the Committee uses to formulate recommendations, including required data; and areas for improvement.

Bacterial meningitis incidence in Thai children estimated by a rapid assessment tool (RAT).

Acute bacterial meningitis is an important cause of morbidity and mortality in children. To estimate the incidence of meningitis caused by all types of bacteria in Thai children under five years of age, data were collected using a rapid assessment tool (RAT) and analyzed. Clinical and laboratory data from suspected meningitis cases for a one-year period were retrospectively collected from 5 selected catchment areas located in the 4 regions of the country. Adjusted incidences of confirmed bacterial meningitis were calculated based on laboratory quality and lumbar puncture rates. Seventy-five suspected meningitis cases were identified among 305,023 children under age five in the catchment areas, with an unadjusted incidence of 24.6 per 100,000. Of these, 66.2, 55.9, and 33.8% were unconfirmed bacterial, purulent, and confirmed bacterial meningitis cases, respectively. Among the confirmed bacterial meningitis cases, 39.1, 26.1, 21.7 and 13.0% were caused by Haemophilus influenzae type B, gram-positive cocci, gram-negative bacilli, and Neisseria meningitidis, respectively. After adjusting based on the RAT application, the incidence of confirmed bacterial meningitis was about double that of the unadjusted incidence. This study gives an interval of possible incidences of bacterial meningitis in children under age five, which is between the unadjusted (low estimate) and adjusted (high estimate) incidences.

Factors associated with diagnosis of bacterial pneumonia in children of Northern Thailand.

The purpose of this study was to determine the association between common clinical features in general practice, and chest radiographic findings among children with suspected bacterial or viral pneumonia. The study was prospective hospital-based carried out in Northern Thailand, from 2000 to 2001. One thousand three hundred ninety-six children under age five years admitted with suspected pneumonia were enrolled in the study. Multinomial logistic regression was used to analyze the radiographic results, clinical outcomes, white blood cell (WBC) counts, percent poly-morphonuclear cells (% PMN), duration of illness before admission, body temperature, age, and gender as variables. Chest radiographs were read by a radiologist following the recommendations of the WHO regarding chest radiographic reading. Chest radiographic findings were classified as normal, viral or bacterial. Fifty-nine children (4.2%) had normal radiographic findings, 1,233 (88.3%) had a viral appearance on chest radiograph, and 104 (7.5%) had a bacterial appearance of chest radiograph. On unadjusted analysis, WBC count, % PMN, body temperature, duration of illness before admission, and gender were strongly associated with outcomes (p < 0.05). On multivariate analysis, only % PMN, duration of illness before admission, and gender were associated with the findings of the chest radiograph. A PMN results of 40% to 70% [RRR, 5.64; 95% confidence interval (CI), 2.14-14.82], PMN > 70% (RRR, 5.11; 95% CI = 1.71-15.22), and duration of illness > 4 days (RRR, 5.19; 95% CI = 1.79-15.06) were positively associated with bacterial radiographic profile. Female (RRR, 0.50; 95% CI = 0.29-0.85) was negatively associated with viral radiographic profile. WBC counts in children admitted with suspected pneumonia were not associated with chest radiograph findings, but % PMN and duration of illness before admission were positively associated with a bacterial radiographic result.

Prospective population-based incidence of Haemophilus influenzae type b meningitis in Thailand.

There are limited prospective data for Haemophilus influenzae type b (Hib) disease in Asia, where some countries are considering vaccine introduction. A prospective population-based study was conducted to measure the incidence of Hib meningitis in children in two northern provinces of Thailand. Children <5 years with symptoms consistent with bacterial meningitis were enrolled in the study if inclusion criteria were met. The study enrolled 598 children with clinical meningitis, 76% of whom received lumbar puncture. The rate of probable bacterial meningitis was 26.6/100,000 children <5 years per year. There were four cases of laboratory confirmed Hib meningitis (rate 3.8/100,000 children <5 years per year). These findings suggest a relatively low incidence of Hib meningitis. However, additional data from studies of pneumonia are needed to define the Hib disease burden in Thailand.