Safety and immunogenicity of an egg-based inactivated Newcastle disease virus vaccine expressing SARS-CoV-2 spike: Interim results of a randomized, placebo-controlled, phase 1/2 trial in Vietnam

Production of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and middle-income countries is needed. NDV-HXP-S is an inactivated egg-based Newcastle disease virus (NDV) vaccine expressing the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Wuhan-Hu-1. The spike protein was stabilized and incorporated into NDV virions by removing the polybasic furin cleavage site, introducing the transmembrane domain and cytoplasmic tail of the fusion protein of NDV, and introducing six prolines for stabilization in the prefusion state. Vaccine production and clinical development was initiated in Vietnam, Thailand, and Brazil. Here the interim results from the first stage of the randomized, dose-escalation, observer-blind, placebo-controlled, phase 1/2 trial conducted at the Hanoi Medical University (Vietnam) are presented. Healthy adults aged 18-59 years, non-pregnant, and with self-reported negative history for SARS-CoV-2 infection were eligible. Participants were randomized to receive one of five treatments by intramuscular injection twice, 28 days apart: 1 μg +/- CpG1018 (a toll-like receptor 9 agonist), 3 μg alone, 10 μg alone, or placebo. Participants and personnel assessing outcomes were masked to treatment. The primary outcomes were solicited adverse events (AEs) during 7 days and subject-reported AEs during 28 days after each vaccination. Investigators further reviewed subject-reported AEs. Secondary outcomes were immunogenicity measures (anti-spike immunoglobulin G [IgG] and pseudotyped virus neutralization). This interim analysis assessed safety 56 days after first vaccination (day 57) in treatment-exposed individuals and immunogenicity through 14 days after second vaccination (day 43) per protocol. Between March 15 and April 23, 2021, 224 individuals were screened and 120 were enrolled (25 per group for active vaccination and 20 for placebo). All subjects received two doses. The most common solicited AEs among those receiving active vaccine or placebo were all predominantly mild and included injection site pain or tenderness (<58%), fatigue or malaise (<22%), headache (<21%), and myalgia (<14%). No higher proportion of the solicited AEs were observed for any group of active vaccine. The proportion reporting vaccine-related AEs during the 28 days after either vaccination ranged from 4% to 8% among vaccine groups and was 5% in controls. No vaccine-related serious adverse event occurred. The immune response in the 10 μg formulation group was highest, followed by 1 μg + CpG1018, 3 μg, and 1 μg formulations. Fourteen days after the second vaccination, the geometric mean concentrations (GMC) of 50% neutralizing antibody against the homologous Wuhan-Hu-1 pseudovirus ranged from 56.07 IU/mL (1 μg, 95% CI 37.01, 84.94) to 246.19 IU/mL (10 μg, 95% CI 151.97, 398.82), with 84% to 96% of vaccine groups attaining a ≥ 4-fold increase over baseline. This was compared to a panel of human convalescent sera (N = 29, 72.93 95% CI 33.00-161.14). Live virus neutralization to the B.1.617.2 (Delta) variant of concern was reduced but in line with observations for vaccines currently in use. Since the adjuvant has shown modest benefit, GMC ratio of 2.56 (95% CI, 1.4-4.6) for 1 μg +/- CpG1018, a decision was made not to continue studying it with this vaccine. NDV-HXP-S had an acceptable safety profile and potent immunogenicity. The 3 μg dose was advanced to phase 2 along with a 6 μg dose. The 10 μg dose was not selected for evaluation in phase 2 due to potential impact on manufacturing capacity. ClinicalTrials.gov NCT04830800.

Spatiotemporal Epidemiology of Tuberculosis in Thailand from 2011 to 2020

Tuberculosis is a leading cause of infectious disease globally, especially in developing countries. Better knowledge of spatial and temporal patterns of tuberculosis burden is important for effective control programs as well as informing resource and budget allocation. Studies have demonstrated that TB exhibits highly complex dynamics in both spatial and temporal dimensions at different levels. In Thailand, TB research has been primarily focused on surveys and clinical aspects of the disease burden with little attention on spatiotemporal heterogeneity. This study aimed to describe temporal trends and spatial patterns of TB incidence and mortality in Thailand from 2011 to 2020. Monthly TB case and death notification data were aggregated at the provincial level. Age-standardized incidence and mortality were calculated; time series and global and local clustering analyses were performed for the whole country. There was an overall decreasing trend with seasonal peaks in the winter. There was spatial heterogeneity with disease clusters in many regions, especially along international borders, suggesting that population movement and socioeconomic variables might affect the spatiotemporal distribution in Thailand. Understanding the space-time distribution of TB is useful for planning targeted disease control program activities. This is particularly important in low- and middle-income countries including Thailand to help prioritize allocation of limited resources.

Long-term effectiveness of human papillomavirus vaccines among adult women: A real-world scenario

OBJECTIVE

This study aimed to determine the real-world effectiveness of bi- or quadrivalent human papillomavirus (HPV) vaccines in Thai adult women ≥5 years post-vaccination in reducing HPV 16/18-associated low-grade squamous intraepithelial lesions or worse (LSIL+), atypical squamous cells of undetermined significance or worse (ASC-US+), and HPV 16/18 positivity.

METHODS

A retrospective cohort study was conducted among Thai women aged 20-45 years in Bangkok. The vaccinated and unvaccinated groups were matched according to baseline years. HPV/Pap test results were collected from the medical records and/or obtained by cervical sample collection at the study sites. Adjusted hazard ratios were measured using multivariable Cox regression analyses.

RESULTS

A total of 993 participants (493 vaccinated and 500 unvaccinated) were enrolled from 2018 to 2019. The median ages at baseline of the vaccinated and unvaccinated groups were 33 years (interquartile range [IQR] 27-38) and 34 years (IQR 30-38), respectively. The median follow-up periods were 7.3 years (IQR 6.1-8.6) and 7.2 years (IQR 5.8-8.9) for the vaccinated group and the unvaccinated group, respectively. More women in the vaccinated group were single (29.2% vs. 13.2%, P < 0.001) and university graduates (83.2% vs. 75.4%, P = 0.009). The vaccinated and unvaccinated groups had similar personal monthly incomes (>20,000 THB/month, 63.9% vs. 62.4%, respectively, P = 0.685). There were no cases of HPV 16/18-associated LSIL+ in the vaccinated group, whereas there were four cases in the unvaccinated group. HPV vaccine effectiveness was 88.0% (95% CI 2.0-98.5) in the reduction of HPV 16/18-associated ASC-US+, and 84.6% (95% CI 43.5-95.8) in the reduction of HPV 16/18 positivity.

CONCLUSIONS

HPV vaccine effectiveness was high in adult women in a real-world scenario in a developing country. Free HPV vaccination in adult women in this age group should be further explored when vaccine supplies are not limited. (HPV: human papillomavirus. LSIL+: low-grade squamous intraepithelial lesion or worse. ASC-US+: atypical squamous cells of undetermined significance or worse).

Safety and immunogenicity of an inactivated recombinant Newcastle disease virus vaccine expressing SARS-CoV-2 spike: Interim results of a randomised, placebo-controlled, phase 1 trial

BACKGROUND

Production of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and middle-income countries is needed. NDV-HXP-S is an inactivated egg-based recombinant Newcastle disease virus vaccine expressing the spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It's being developed by public sector manufacturers in Thailand, Vietnam, and Brazil; herein are initial results from Thailand.

METHODS

This phase 1 stage of a randomised, dose-escalation, observer-blind, placebo-controlled, phase 1/2 trial was conducted at the Vaccine Trial Centre, Mahidol University (Bangkok). Healthy males and non-pregnant females, aged 18-59 years and negative for SARS-CoV-2 antibodies, were eligible. Participants were randomised to receive one of six treatments by intramuscular injection twice, 28 days apart: 1 µg, 1 µg+CpG1018 (a toll-like receptor 9 agonist), 3 µg, 3 µg+CpG1018, 10 µg, or placebo. Participants and personnel assessing outcomes were masked to treatment. The primary outcomes were solicited and spontaneously reported adverse events (AEs) during 7 and 28 days after each vaccination, respectively. Secondary outcomes were immunogenicity measures (anti-S IgG and pseudotyped virus neutralisation). An interim analysis assessed safety at day 57 in treatment-exposed individuals and immunogenicity through day 43 per protocol. ClinicalTrials.gov (NCT04764422).

FINDINGS

Between March 20 and April 23, 2021, 377 individuals were screened and 210 were enroled (35 per group); all received dose one; five missed dose two. The most common solicited AEs among vaccinees, all predominantly mild, were injection site pain (<63%), fatigue (<35%), headache (<32%), and myalgia (<32%). The proportion reporting a vaccine-related AE ranged from 5·7% to 17·1% among vaccine groups and was 2·9% in controls; there was no vaccine-related serious adverse event. The 10 µg formulation's immunogenicity ranked best, followed by 3 µg+CpG1018, 3 µg, 1 µg+CpG1018, and 1 µg formulations. On day 43, the geometric mean concentrations of 50% neutralising antibody ranged from 122·23 international units per mL (IU/mL; 1 µg, 95% confidence interval (CI) 86·40-172·91) to 474·35 IU/mL (10 µg, 95% CI 320·90-701·19), with 93·9% to 100% of vaccine groups attaining a ≥ 4-fold increase over baseline.

INTERPRETATION

NDV-HXP-S had an acceptable safety profile and potent immunogenicity. The 3 µg and 3 µg+CpG1018 formulations advanced to phase 2.

FUNDING

National Vaccine Institute (Thailand), National Research Council (Thailand), Bill & Melinda Gates Foundation, National Institutes of Health (USA).

Confronting and Coping with Multidrug-Resistant Tuberculosis: Life Experiences in Thailand

In this article, we aimed to understand the life experiences of Thai persons diagnosed with multi-drug-resistant tuberculosis (MDR-TB). A qualitative study using a face-to-face in-depth interview was conducted at a hospital in Thailand which has the highest prevalence of MDR-TB in the country between January and February 2019. Twenty persons living with MDR-TB in Thailand were purposively selected to represent a variety of experiences based on different gender, ages, and treatment phases. Qualitative data were transcribed and thematic analysis was applied to identify common themes and sub-themes. The results indicated that all participants faced emotional difficulties, such as fear of death, fear of stigmatization, confusion, and sadness when first knowing of their diagnosis. Family and social support were the main ways that the patients coped with difficult situations. Suicidal ideas were more prevalent among patients with poor family support. Screening for mental health problems should be routinely performed in MDR-TB patients. Proper health education should be provided to patients and families to reduce emotional difficulties and stigmatization.

Knowledge, attitude, and practices toward COVID-19 among the international travelers in Thailand

BACKGROUND

International travel is among the leading impactful factors of COVID-19 transmission; thus, adequate knowledge, good attitude and good preventive practices toward COVID-19 for international travelers are particularly essential for successful pandemic control.

METHODS

A cross-sectional, questionnaire-based study was conducted to determine knowledge, attitude and practices (KAP) of international travelers (both Thai and non-Thai) and expatriates in Thailand. The data were collected at the Thai Travel Clinic, Bangkok, Thailand and via online platforms during May to October 2020. The independent T-test, Chi-square test and multiple regression analysis (MRA) were applied to determine factors influencing the KAP.

RESULTS

Of 399 travelers, 46.6% were male, 72.1% had a Bachelor's degree or higher, and the mean age was 35.6 ± 9.6 years. Due to unexpected travel restrictions and lock down, 77.9% of participants were Thai and the respective major purpose of travel was business/work. Travel cancellation/postponement was reported at 73.9%. While sufficient knowledge (≥ 60% correct answers) was reported in 77.9% of participants, a low percentage of correct answers was found in the questions regarding disease transmission. The travelers reported a neutral attitude and an overall moderate concern regarding the COVID-19 situation. Adequate preventive practices were determined by the average practice score 3.54 ± 0.38 (0 = never and 4 = always). The MRA revealed that the factors influencing good practices were travelers who: i) enrolled from outside the hospital (online platform); ii) received pretravel advice at hospital; iii) were female; iv) participated before the declaration of the end of the outbreak; v) were aged 40-49 years, and vi) visited friends and relatives.

CONCLUSIONS

The majority of travelers in this study had sufficient knowledge, a neutral attitude and adequate preventive practices toward COVID-19. The factors influencing good practices included pretravel advice, sex, age and the point in the timeline of the outbreak. In order to better control the COVID-19 pandemic situation, pretravel counselling and advice should be promoted as a means to improve knowledge, particularly in disease transmission, increase awareness and emphasize appropriate preventive measures toward COVID-19 among international travelers. Furthermore, preventive practices should be bolstered at all times regardless of the outbreak situation.

Safety and Immunogenicity of an Inactivated Recombinant Newcastle Disease Virus Vaccine Expressing SARS-CoV-2 Spike: Interim Results of a Randomised, Placebo-Controlled, Phase 1/2 Trial

Background

Production of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and middle-income countries is needed. NDV-HXP-S is an inactivated egg-based Newcastle disease virus vaccine expressing the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It's being developed in Thailand, Vietnam, and Brazil; herein are initial results from Thailand.

Methods

This phase 1 stage of a randomised, dose-escalation, observer-blind, placebo-controlled, phase 1/2 trial was conducted at the Vaccine Trial Centre, Mahidol University (Bangkok). Healthy adults aged 18-59 years, non-pregnant and negative for SARS-CoV-2 antibodies were eligible. Participants were block randomised to receive one of six treatments by intramuscular injection twice, 28 days apart: 1 µg±CpG1018 (a toll-like receptor 9 agonist), 3 µg±CpG1018, 10 µg, or placebo. Participants and personnel assessing outcomes were masked to treatment. The primary outcomes were solicited and spontaneously reported adverse events (AEs) during 7 and 28 days after each vaccination, respectively. Secondary outcomes were immunogenicity measures (anti-S IgG and pseudotyped virus neutralisation). An interim analysis assessed safety at day 57 in treatment-exposed individuals and immunogenicity through day 43 per protocol. ClinicalTrials.gov ( NCT04764422 ).

Findings

Between March 20 and April 23, 2021, 377 individuals were screened and 210 were enrolled (35 per group); all received dose one; five missed dose two. The most common solicited AEs among vaccinees, all predominantly mild, were injection site pain (<63%), fatigue (<35%), headache (<32%), and myalgia (<32%). The proportion reporting a vaccine-related AE ranged from 5·7% to 17·1% among vaccine groups and was 2·9% in controls; there was no vaccine-related serious adverse event. The 10 µg formulation's immunogenicity ranked best, followed by 3 µg+CpG1018, 3 µg, 1 µg+CpG1018, and 1 µg formulations. On day 43, the geometric mean concentrations of 50% neutralising antibody ranged from 122·23 IU/mL (1 µg, 95% CI 86·40-172·91) to 474·35 IU/mL (10 µg, 95% CI 320·90-701·19), with 93·9% to 100% of vaccine groups attaining a ≥4-fold increase over baseline.

Interpretation

NDV-HXP-S had an acceptable safety profile and potent immunogenicity. The 3 µg and 3 µg+CpG1018 formulations advanced to phase 2.

Funding

National Vaccine Institute (Thailand), National Research Council (Thailand), Bill & Melinda Gates Foundation, National Institutes of Health (USA).

Ownership and utilization of bed nets and reasons for use or non-use of bed nets among community members at risk of malaria along the Thai-Myanmar border

Background

With the goal for malaria elimination in Thailand set for 2024, increased coverage and utilization of bed net, especially insecticide-treated net (ITN) or long-lasting insecticidal net (LLIN) is a key strategy. This study aims to provide the necessary information about bed net ownership and utilization among the population at risk of malaria living along the Thai-Myanmar border in Tak province.

Methods

A cross-sectional study was conducted using a mixed-method approach in 331 households from 5 hamlets in the villages of the Thai-Myanmar border. The research tools included a questionnaire, bed net inspection, and semi-structured interviews. Logistic regression was used to explore the sociodemographic factors associated with bed net utilization. The qualitative analysis employed a thematic analysis approach.

Results

This survey found that 98.5% of households had at least one bed net per household, and 74.3% had at least one ITN/LLIN. However, only 30.8% of households reached the standard policy set by the Minister of Public Health of one ITN/LLINs per two persons. Most residents used bed net (92.1% used in the previous night and 80.9% used every day). For those using bed nets, however, 61.9% used ITNs or LLINs the night before and 53.1% used them every day. Nonetheless, the usage rates of bed nets (any type) in the previous night among children and pregnant women were high, reaching 95.3% and 90.0%, respectively. Seven explanatory variables showed statistically significant associations with bed net use every day, including: “not staying overnight in the forest or the field”, “sleeping pattern based on gender”, “sufficient numbers of bed nets to cover all sleeping spaces”, “preference for free bed nets”, “age”, “gender”, and “SES score” showed statistically significant association with bed net use every day. The major reasons for the regular use of bed nets in both household and the forest were to prevent mosquito biting. The reasons for not using bednets in the household were discomfort feelings from heat, perception of unnecessity due to low mosquito density, whereas the reason for not using bed nets in the forest was inconvenience.

Conclusion

Despite that overall coverage and usage of bed nets was high, only one third reached the standard level specified by the policy. Overnight in the forest, the dissatisfaction with the quality of free bed nets, insufficient number of bed nets, sleeping alone, male gender, age more than 10 years, low socioeconomic status, discomfort from heat, perception of no benefits of bed nets due to low mosquito density, and inconvenience were factors influencing bed net use. Maintaining high coverage and utility rate of bed nets should be a priority for the malaria high-risk population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03837-5.

Effects of large volume, isotonic nasal saline irrigation for acute rhinosinusitis: a randomized controlled study

BACKGROUND

The purpose of this study was to compare the effects of nasal saline irrigation (large volume, positive pressure isotonic saline) in addition to standard treatment in patients with acute rhinosinusitis (ARS).

METHODS

This parallel, randomized controlled trial was conducted at a tertiary hospital. The adult patients with ARS (age ≥18 years) were randomly assigned to two groups. The irrigation group received 0.9% saline irrigation twice daily, using a 250-ml squeeze bottle, in addition to standard treatment. The no-irrigation group received standard treatment only. Patients were evaluated at baseline, 1 week, and 2 weeks. The quality of life, rhinologic subscore, symptom score, endoscopy score, and cure rate were compared.

RESULTS

Sixty-one patients (30: irrigation, 31: no-irrigation) were enrolled. There were 17 males and 44 females. The mean age was 41.06 years. Although both groups showed improvements, the improvement of each outcome was not different between the groups. Subgroup analysis by ARS subtype showed benefits of irrigation in the common cold subgroup; the improvements that were greater than control included: rhinologic subscore, intergroup mean difference -4.15 [95% confidence interval (CI), -7.49, -0.80] at 1 week and -5.23 [95% CI, -9.69, -0.78] at 2 weeks; combined symptom score -5.35 [95% CI, -10.55, -0.14] at 1 week and -8.02 [95%CI, -14.36, -1.70] at 2 weeks.

CONCLUSION

The add-on isotonic nasal saline irrigation using a large volume, positive pressure device did not add benefits equally for all ARS patients. The benefits of irrigation on quality of life and nasal symptoms were only observed in the common cold patient subgroup.

Assessing the impacts of short-course multidrug-resistant tuberculosis treatment in the Southeast Asia Region using a mathematical modeling approach

This study aimed to predict the impacts of shorter duration treatment regimens for multidrug-resistant tuberculosis (MDR-TB) on both MDR-TB percentage among new cases and overall MDR-TB cases in the WHO Southeast Asia Region. A deterministic compartmental model was constructed to describe both the transmission of TB and the MDR-TB situation in the Southeast Asia region. The population-level impacts of short-course treatment regimens were compared with the impacts of conventional regimens. Multi-way analysis was used to evaluate the impact by varying programmatic factors (eligibility for short-course MDR-TB treatment, treatment initiation, and drug susceptibility test (DST) coverage). The model predicted that overall TB incidence will be reduced from 246 (95% credible intervals (CrI), 221–275) per 100,000 population in 2020 to 239 (95% CrI, 215–267) per 100,000 population in 2035, with a modest reduction of 2.8% (95% CrI, 2.7%–2.9%). Despite the slight reduction in overall TB infections, the model predicted that the MDR-TB percentage among newly notified TB infections will remain steady, with 2.4% (95% CrI, 2.1–2.9) in 2020 and 2.5% (95% CrI, 2.3–3.1) in 2035, using conventional MDR-TB treatment. With the introduction of short-course regimens to treat MDR-TB, the development of resistance can be slowed by 38.6% (95% confidence intervals (CI), 35.9–41.3) reduction in MDR-TB case number, and 37.6% (95% CI, 34.9–40.3) reduction in MDR-TB percentage among new TB infections over the 30-year period compared with the baseline using the standard treatment regimen. The multi-way analysis showed eligibility for short-course treatment and treatment initiation greatly influenced the impacts of short-course treatment regimens on reductions in MDR-TB cases and percentage resistance among new infections. Policies which promote the expansion of short-course regimens and early MDR-TB treatment initiation should be considered along with other interventions to tackle antimicrobial resistance in the region.

Effects of COVID-19 government travel restrictions on mobility in a rural border area of Northern Thailand: A mobile phone tracking study

BACKGROUND

Thailand is among the top five countries with effective COVID-19 transmission control. This study examines how news of presence of COVID-19 in Thailand, as well as varying levels of government restriction on movement, affected human mobility in a rural Thai population along the border with Myanmar.

METHODS

This study makes use of mobility data collected using a smartphone app. Between November 2019 and June 2020, four major events concerning information dissemination or government intervention give rise to five time intervals of analysis. Radius of gyration is used to analyze movement in each interval, and movement during government-imposed curfew. Human mobility network visualization is used to identify changes in travel patterns between main geographic locations of activity. Cross-border mobility analysis highlights potential for intervillage and intercountry disease transmission.

RESULTS

Inter-village and cross-border movement was common in the pre-COVID-19 period. Radius of gyration and cross-border trips decreased following news of the first imported cases. During the government lockdown period, radius of gyration was reduced by more than 90% and cross-border movement was mostly limited to short-distance trips. Human mobility was nearly back to normal after relaxation of the lockdown.

CONCLUSIONS

This study provides insight into the impact of the government lockdown policy on an area with extremely low socio-economic status, poor healthcare resources, and highly active cross-border movement. The lockdown had a great impact on reducing individual mobility, including cross-border movement. The quick return to normal mobility after relaxation of the lockdown implies that close monitoring of disease should be continued to prevent a second wave.

Preliminary estimation of temporal and spatiotemporal dynamic measures of COVID-19 transmission in Thailand

BACKGROUND

As a new emerging infectious disease pandemic, there is an urgent need to understand the dynamics of COVID-19 in each country to inform planning of emergency measures to contain its spread. It is essential that appropriate disease control activities are planned and implemented in a timely manner. Thailand was one of the first countries outside China to be affected with subsequent importation and domestic spread in most provinces in the country.

METHOD

A key ingredient to guide planning and implementation of public health measures is a metric of transmissibility which represents the infectiousness of a disease. Ongoing policies can utilize this information to plan appropriately with updated estimates of disease transmissibility. Therefore we present descriptive analyses and preliminary statistical estimation of reproduction numbers over time and space to facilitate disease control activities in Thailand.

RESULTS

The estimated basic reproduction number for COVID-19 during the study ranged from 2.23-5.90, with a mean of 3.75. We also tracked disease dynamics over time using temporal and spatiotemporal reproduction numbers. The results suggest that the outbreak was under control since the middle of April. After the boxing stadium and entertainment venues, the numbers of new cases had increased and spread across the country.

DISCUSSION

Although various scenarios about assumptions were explored in this study, the real situation was difficult to determine given the limited data. More thorough mathematical modelling would be helpful to improve the estimation of transmissibility metrics for emergency preparedness as more epidemiological and clinical information about this new infection becomes available. However, the results can be used to guide interventions directly and to help parameterize models to predict the impact of these interventions.

User Acceptance of Electronic Medical Record System: Implementation at Marie Stopes International, Myanmar

Objectives

This study assessed the technical feasibility and aimed to determine the factors influencing intention to use Electronic Medical Records (EMRs) at Marie Stopes International, Myanmar (MSI-M).

Methods

A cross-sectional survey was conducted among 112 participants who were working at the clinics and head office of MSI-M. Demographic information, type of office, technical feasibility, information communication technology knowledge, computer usage, and user acceptance towards the proposed system were obtained from the participants.

Results

The results indicated low health information technology usage and network availability at MSI-M clinics. Positive perception of EMRs was found among the staff members of MSI-M, which was reflected by positive responses regarding perceived usefulness (average score of 4.15), perceived ease of use (average score of 4.03), and intention to use (average score of 4.10) on a 5-point Likert scale. Statistically, staff from the head office expressed less desire to implement an EMR system (odds ratio = 0.07; 95% confidence interval, 0.01–0.97), especially when they do not perceive the usefulness of the system (odds ratio = 5.05; 95% confidence interval, 2.39–10.69).

Conclusions

Since health information technology usage and network availability were low in MSI-M, it is important to strengthen the information and communication technology infrastructure and introduce a policy for capacity building at MSI-M. Adequate training and strong leadership support are recommended for the successful initial implementation and sustainability of an EMR system at MSI-M.

Health Literacy Toward Zoonotic Diseases Among Livestock Farmers in Vietnam

BACKGROUND

Zoonoses are an increasing concern worldwide, particularly in low- and middle-income countries. People with close contact with animals are at high risk for contracting and transmitting the zoonotic diseases.

OBJECTIVES

To determine health literacy of livestock farmers toward biosecurity to prevent zoonotic diseases.

METHODS

This cross-sectional mixed-methods study was conducted in Thai Nguyen Province, Vietnam, where livestock and farming are the main occupation. The questionnaire survey was submitted to 218 farmers who have close contact with livestock. In addition, 8 farmers were invited to an in-depth interview to further explore the health literacy.

RESULTS

Half of the participants were men. The average age (standard deviation) of the participants was 49.3(11.5) years. The median years with experience in farming was 15 years. The majority (82.0%) of the participants had moderate health literacy level regarding zoonoses. Improper use of antibiotics was referred by 58.0% of participants, including antibiotic use as feeding supplements (34.0%) and the use of human antibiotics to treat sick animals (24.0%). Many participants were unaware of zoonotic prevention measures and due to this had practices such as not wearing protective equipment (60.0%), an absence of acaricides to prevent vector infestations (52.0%), an absence of disinfection measures (42.0%), low rate of rabies vaccination (54.0%), and do not quarantining sick animals (38.0%). In-depth interviews revealed great concern among farmers about a collective lack of participation from local veterinarians, health workers, and government authorities in zoonoses-prevention efforts. Statistical models showed that farm scale, ethnic groups, and perceived income were associated with the overall health literacy about zoonoses.

CONCLUSION

Comprehensive health education related to zoonotic diseases is recommended to improve overall knowledge, including routes of transmission, symptoms and consequences of diseases, and antibiotic usage. In addition, guidance should be provided to farmers on how to treat sick animals, the appropriate use of antibiotics, and waste management. Local veterinarians and health workers are important contact points and should work closely with the farmers to prevent zoonotic diseases.

Accuracy of childhood asthma control test among Thai childhood asthma patients

BACKGROUND

The Childhood Asthma Control Test (C-ACT) was developed to assess asthma control in children worldwide. A self-administered questionnaire for children translated into Thai language was used.

OBJECTIVE

To validate the C-ACT cut-points for evaluating the level of asthma control among Thai children, using the Global Initiative for Asthma (GINA) guideline as a gold standard.

METHODS

C-ACT score, FEV1 and assessment of level of asthma control were recorded at baseline, 3-month, 6-month, and 1-year visits among children with asthma. Receiver operating characteristic (ROC) curves was used to determine the area under the curve (AUC) of C-ACT score for determining the level of asthma control. Validity indicators were calculated at different C-ACT cut-points to determine those most appropriate for predicting controlled and uncontrolled asthma.

RESULTS

We enrolled 279 children, 64% males, with mean age 6.87±2.4 years. C-ACT score was significantly correlated with FEV1 at 3-month, 6-month, and 1-year visits (p<0.001). The AUC of C-ACT score compared with GINA score were above 80% at all visits. The suggested C-ACT score cut-point of controlled asthma was ≥ 23 (sensitivity 69.5%, specificity 73.3%, positive predictive value (PPV) 81.2%, negative predictive value (NPV) 63.8%); that of uncontrolled asthma was ≤ 18 (sensitivity 54.2%, specificity 96.9%, PPV 61.9%, NPV 95.7%).

CONCLUSIONS

The Thai version of the C-ACT is an accurate, simple, and useful tool for assessing asthma control among Thai children. The high AUC suggests that the Thai C-ACT is as good as the GINA guideline in predicting asthma control level.

Malaria cross-sectional surveys identified asymptomatic infections of Plasmodium falciparum, Plasmodium vivax and Plasmodium knowlesi in Surat Thani, a southern province of Thailand

OBJECTIVES

Malaria cross-sectional surveys are rarely conducted in very low transmission settings. This study aimed to determine the prevalence and risk factors of Plasmodium infection in a near-elimination setting in southern Thailand.

METHODS

Two cross-sectional surveys were conducted in areas of active transmission in the Surat Thani province of Thailand in January and May 2019. PCR was used to detect Plasmodium infection.

RESULTS

The prevalence of Plasmodium blood infection was 0.45% and 0.61% in January and May 2019, respectively. The major parasite species was Plasmodium falciparum in January and Plasmodium vivax in May. Unexpectedly, Plasmodium knowlesi infections were also detected. Most infections, including those of Plasmodium knowlesi, were asymptomatic. Being male and staying outdoors at night-time were the only significant identified risk factors. Of people infected in January 28.0% were positive in May for the same parasite species, suggesting persistent asymptomatic infections.

CONCLUSIONS

Despite the very low incidence rate in Surat Thani, most malaria infections were asymptomatic. Outdoor mosquito biting at night-time is likely an important mode of malaria transmission. Unexpectedly, asymptomatic Plasmodium knowlesi infection was found, confirming previous reports of such infection in mainland Southeast Asia.

Boosting Teenagers With Acellular Pertussis Vaccines Containing Recombinant or Chemically Inactivated Pertussis Toxin: A Randomized Clinical Trial

BACKGROUND

Protection induced by acellular pertussis (aP) vaccines is partial and short-lived, especially in teenagers, calling for novel immunization strategies.

METHODS

We conducted an investigator-driven proof-of-concept randomized controlled trial in aP-primed adolescents in Geneva to assess the immunogenicity and reactogenicity of a novel recombinant aP (r-aP) vaccine including recombinant pertussis toxin (PT) and filamentous hemagglutinin (FHA) coadministered with tetanus-diphtheria toxoids (Td), compared to a licensed tetanus-diphtheria-aP vaccine containing chemically detoxified PT (cd/Tdap). The primary immunological endpoints were day 28/365 geometric mean concentrations (GMCs) of total and neutralizing anti-PT antibodies. Memory B cells were assessed.

RESULTS

Sixty-two aP-primed adolescents were randomized and vaccinated with r-aP + Td or cd/Tdap. Reactogenicity, adverse events, and baseline GMCs were similar between the groups. Day 28 PT-neutralizing GMCs were low after cd/Tdap (73.91 [95% confidence interval {CI}, 49.88-109.52] IU/mL) and approximately 2-fold higher after r-aP + Td (127.68 [95% CI, 96.73-168.53] IU/mL; P = .0162). Anti-PT GMCs were also low after cd/Tdap (52.43 [95% CI, 36.41-75.50] IU/mL) and 2-fold higher after r-aP + Td (113.74 [95% CI, 88.31-146.50] IU/mL; P = .0006). Day 28 anti-FHA GMCs were similar in both groups. Day 365 anti-PT (but not PT-neutralizing) GMCs remained higher in r-aP + Td vaccinees. PT-specific memory B cells increased significantly after r-aP + Td but not cd/Tdap boosting.

CONCLUSIONS

Boosting aP-primed adolescents with r-aP induced higher anti-PT and PT-neutralizing responses than cd/Tdap and increased PT-specific memory B cells. Despite this superior immunogenicity, r-aP may have to be given repeatedly, earlier, and/or with novel adjuvants to exert an optimal influence in aP-primed subjects.

CLINICAL TRIALS REGISTRATION

NCT02946190.

Exposure to Heavy Metals in Electronic Waste Recycling in Thailand

Electronic waste recycling can release heavy metals into the environment and cause adverse health effects. We assessed the association between exposure to heavy metals from electronic waste recycling and the prevalence of asthma in a nested case-control study of 51 subject pairs with and without asthma. House dust, airborne dust, blood, and urine were collected from residents of two neighboring sites in Ubon Ratchathani province, Thailand. Multiple electronic waste-handling activities are conducted in the first site, while the second site is mostly agricultural. Concentrations of chromium, mercury, nickel, and lead in house dust and airborne dust were higher in the electronic waste-handling site (p < 0.05), but levels of exposure were similar in subjects with and without asthma. Although we did not find an association between exposure to these metals and the prevalence of asthma, control measures should be implemented to reduce health risks from long-term exposure to heavy metals.

Dynamics of Plasmodium vivax populations in border areas of the Greater Mekong sub-region during malaria elimination

Background

Countries within the Greater Mekong Sub-region (GMS) of Southeast Asia have committed to eliminating malaria by 2030. Although the malaria situation has greatly improved, malaria transmission remains at international border regions. In some areas, Plasmodium vivax has become the predominant parasite. To gain a better understanding of transmission dynamics, knowledge on the changes of P. vivax populations after the scale-up of control interventions will guide more effective targeted control efforts.

Methods

This study investigated genetic diversity and population structures in 206 P. vivax clinical samples collected at two time points in two international border areas: the China-Myanmar border (CMB) (n = 50 in 2004 and n = 52 in 2016) and Thailand-Myanmar border (TMB) (n = 50 in 2012 and n = 54 in 2015). Parasites were genotyped using 10 microsatellite markers.

Results

Despite intensified control efforts, genetic diversity remained high (H_E = 0.66–0.86) and was not significantly different among the four populations (P > 0.05). Specifically, H_E slightly decreased from 0.76 in 2004 to 0.66 in 2016 at the CMB and increased from 0.80 in 2012 to 0.86 in 2015 at the TMB. The proportions of polyclonal infections varied significantly among the four populations (P < 0.05), and showed substantial decreases from 48.0% in 2004 to 23.7 at the CMB and from 40.0% in 2012 to 30.7% in 2015 at the TMB, with corresponding decreases in the multiplicity of infection. Consistent with the continuous decline of malaria incidence in the GMS over time, there were also increases in multilocus linkage disequilibrium, suggesting more fragmented and increasingly inbred parasite populations. There were considerable genetic differentiation and sub-division among the four tested populations. Temporal genetic differentiation was observed at each site (F_ST = 0.081 at the CMB and F_ST = 0.133 at the TMB). Various degrees of clustering were evident between the older parasite samples collected in 2004 at the CMB and the 2016 CMB and 2012 TMB populations, suggesting some of these parasites had shared ancestry. In contrast, the 2015 TMB population was genetically distinctive, which may reflect a process of population replacement. Whereas the effective population size (N_e) at the CMB showed a decrease from 4979 in 2004 to 3052 in 2016 with the infinite allele model, the N_e at the TMB experienced an increase from 6289 to 10,259.

Conclusions

With enhanced control efforts on malaria, P. vivax at the TMB and CMB showed considerable spatial and temporal differentiation, but the presence of large P. vivax reservoirs still sustained genetic diversity and transmission. These findings provide new insights into P. vivax transmission dynamics and population structure in these border areas of the GMS. Coordinated and integrated control efforts on both sides of international borders are essential to reach the goal of regional malaria elimination.

Evaluation of Immunization Services for Children of Migrant Workers Along Thailand-Myanmar Border: Compliance with Global Vaccine Action Plan (2011-2020)

Immunization is a core component of the human right to health. However, accessibility to the Expanded Program on Immunization (EPI) might be difficult among migrant children. This study aims to assess the vaccination coverage of migrant children under a mobile immunization program, initiated by the Thai government in 2014. A cross-sectional, mixed-methods study was conducted in five districts along the Thailand-Myanmar border during July-December 2018. The immunization history during their first year of life was obtained. Focus group discussions were conducted among stakeholders to explore their satisfaction toward the immunization service. Mothers/guardians of 1707 migrant children participated in the survey, with a 71% response rate. The vaccination coverage increased during 2014-2017. The highest vaccination coverage was observed for Bacillus CalmetteGuérin vaccine, with 83.2% coverage in 2017. The vaccination coverage of three doses of diphtheriatetanuspertussis vaccine and Hepatitis B vaccine and oral polio vaccine increased from 34.8% in 2014 to 56.3% in 2017. For measles-containing vaccine, the vaccination coverage increased from 32.4% in 2014 to 54.6% in 2017. Overall, all stakeholders were satisfied with the immunization service. Increased workload and communication barriers were the main factors that influenced the satisfaction toward the immunization program.

The Factors associated with the unsuccessful tuberculosis treatment of hill tribe patients in Thailand

INTRODUCTION

Tuberculosis (TB) remains a serious public-health problem worldwide. The successful tuberculosis treatment was in low rate among the hill tribes in Thailand. This study aimed to determine factors associated with the unsuccessful tuberculosis treatment among the hill tribe TB patients in northern Thailand.

METHODOLOGY

A retrospective cohort study was conducted using secondary data from the national TB reporting system. Data of newly registered hill tribe patients with TB receiving treatment were obtained from 18 government hospitals in Chiang Rai province, during 2014-2017. TB treatment outcomes and factors associated with unsuccessful were determined.

RESULTS

A total of 770 hill tribe patients with TB registered during the study period. The majority were males aged 25-64 years. About 80% of the patients lived in rural areas and 53.9% worked in agriculture. The overall TB treatment success rate was 80.4%. Two factors were associated with unsuccessful TB treatment: ages 25-44 and ages 45-64 (aOR 3.14 (1.03-9.55) and 3.02 (1.01-9.03), respectively) and receiving antiretroviral drugs (proxy of HIV infection) (aOR 2.30 (1.02-5.15)).

CONCLUSION

Although the TB treatment success rate among hill tribe patients did not reach the national goal, it was still higher than that of other Thai TB patients in the area. In Thailand, hill tribe people can access health services free-of-charge under the national health insurance. This could influence the successful treatment. However, some barriers need to be considered, such as the high default rate and high death rate among those with HIV coinfection.

Etiologies of Acute Undifferentiated Febrile Illness in Bangkok, Thailand

Acute undifferentiated febrile illness (AUFI) has been a diagnostic dilemma in the tropics. Without accurate point-of-care tests, information on local pathogens and clinical parameters is essential for presumptive diagnosis. A prospective hospital-based study was conducted at the Bangkok Hospital for Tropical Diseases from 2013 to 2015 to determine common etiologies of AUFI. A total of 397 adult AUFI cases, excluding malaria by blood smear, were enrolled. Rapid diagnostic tests for tropical infections were performed on admission, and acute and convalescent samples were tested to confirm the diagnosis. Etiologies could be identified in 271 (68.3%) cases. Dengue was the most common cause, with 157 cases (39.6%), followed by murine typhus (20 cases; 5.0%), leptospirosis (16 cases; 4.0%), influenza (14 cases; 3.5%), and bacteremia (six cases; 1.5%). Concurrent infection by at least two pathogens was reported in 37 cases (9.3%). Furthermore, characteristics of dengue and bacterial infections (including leptospirosis and rickettsioses) were compared to facilitate dengue triage, initiate early antibiotic treatment, and minimize unnecessary use of antibiotics. In conclusion, dengue was the most common pathogen for AUFI in urban Thailand. However, murine typhus and leptospirosis were not uncommon. Empirical antibiotic treatment using doxycycline or azithromycin might be more appropriate, but cost-benefit studies are required. Physicians should recognize common causes of AUFI in their localities and use clinical and laboratory clues for provisional diagnosis to provide appropriate treatment while awaiting laboratory confirmation.

Prevalence and Alternative Treatment of Head-Lice Infestation in Rural Thailand: A Community-Based Study

Head-lice infestation, pediculosis capitis, remains a public-health burden in many countries. The widely used first-line pediculicides and alternative treatments are often too costly for use in poor socio-economic settings. Ivermectin has been considered an alternate treatment for field practice. This study was composed of 2 parts, a cross-sectional survey and an intervention study. The main objectives were to determine the prevalence and potential factors associated with head-lice infestation, and to evaluate the effectiveness and safety of oral ivermectin administration. A community-based cross-sectional survey was conducted among 890 villagers in rural areas along Thai-Myanmar border. Females with infestations were eligible for the intervention study, and 181 participated in the intervention study. A post-treatment survey was conducted to assess acceptance of ivermectin as a treatment choice. Data analysis used descriptive statistics and a generalized-estimation-equation model adjusted for cluster effect. The study revealed the prevalence of head-lice infestation was 50% among females and only 3% among males. Age stratification showed a high prevalence among females aged <20 years, and among 50% of female school-children. The prevalence was persistent among those with a history of infestation. The major risk factors were residing in a setting with other infected cases, and sharing a hair comb. The study also confirmed that ivermectin was safe and effective for field-based practice. It was considered a preferable treatment option. In conclusion, behavior-change communication should be implemented to reduce the observed high prevalence of head-lice infestation. Ivermectin may be an alternative choice for head-lice treatment, especially in remote areas.

Spatiotemporal epidemiology, environmental correlates, and demography of malaria in Tak Province, Thailand (2012-2015)

Background

Tak Province, at the Thai–Myanmar border, is one of three high malaria incidence areas in Thailand. This study aimed to describe and identify possible factors driving the spatiotemporal trends of disease incidence from 2012 to 2015.

Methods

Climate variables and forest cover were correlated with malaria incidence using Pearson’s r. Statistically significant clusters of high (hot spots) and low (cold spots) annual parasite incidence per 1000 population (API) were identified using Getis-Ord Gi* statistic.

Results

The total number of confirmed cases declined by 76% from 2012 to 2015 (Plasmodium falciparum by 81%, Plasmodium vivax by 73%). Incidence was highly seasonal with two main annual peaks. Most cases were male (62.75%), ≥ 15 years (56.07%), and of Myanmar (56.64%) or Thai (39.25%) nationality. Median temperature (1- and 2-month lags), average temperature (1- and 2-month lags) and average relative humidity (2- and 3-month lags) correlated positively with monthly total, P. falciparum and P. vivax API. Total rainfall in the same month correlated with API for total cases and P. vivax but not P. falciparum. At sub-district level, percentage forest cover had a low positive correlation with P. falciparum, P. vivax, and total API in most years. There was a decrease in API in most sub-districts for both P. falciparum and P. vivax. Sub-districts with the highest API were in the Tha Song Yang and Umphang Districts along the Thai–Myanmar border. Annual hot spots were mostly in the extreme north and south of the province.

Conclusions

There has been a large decline in reported clinical malaria from 2012 to 2015 in Tak Province. API was correlated with monthly climate and annual forest cover but these did not account for the trends over time. Ongoing elimination interventions on one or both sides of the border are more likely to have been the cause but it was not possible to assess this due to a lack of suitable data. Two main hot spot areas were identified that could be targeted for intensified elimination activities.

Electronic supplementary material

The online version of this article (10.1186/s12936-019-2871-2) contains supplementary material, which is available to authorized users.

Treatment outcomes for elderly patients in Thailand with pulmonary tuberculosis

Background

Elderly patients with pulmonary tuberculosis are less likely to achieve treatment success than younger patients, and patients aged ≥60 years have a substantial increase in mortality.

Objectives

To compare treatment outcomes over 2 periods during the transition of Thai national tuberculosis (TB) reporting systems and determine treatment success rates and mortality for elderly patients in TB treatment-care settings in Thailand.

Methods

Retrospective cohort study of all records of elderly patients extracted from 2 national TB databases in Thailand: the TB Case Management (TBCM) database of the National TB Program (2014–2015) and the database of the National Health Security Office (NHSO; 2010–2011).

Results

There were 8,301 elderly patients with TB in the TBCM cohort and 11,869 in the NHSO cohort. Overall treatment success rates were 78.5% for patients in the TBCM cohort and 87.5% for patients in the NHSO cohort. High success rates for treatment were found for those aged 60–69 years: 91.1% in 2010–2011 and 85.0% in 2014–2015. High mortality was reported for patients aged ≥90 years: 34.6% in 2010–2011 and 50.0% in 2014–2015.

Conclusions

Compared with the NHSO historical cohort, success rates for treatment were lower and death rates were higher in the TBCM cohort. Because NHSO enforced intensive case monitoring and follow-up while TBCM has no such mechanism, the estimates from the TBCM database may be less accurate for TB circumstances in Thailand. Frequent routine home visits may ensure more complete treatment-care information and support, and increase the treatment success rate in the elderly.