Real-World Effectiveness of COVID-19 Vaccines against Severe Outcomes during the Period of Omicron Predominance in Thailand: A Test-Negative Nationwide Case-Control Study.

Due to the widespread Omicron variant of SARS-CoV-2 in Thailand, the effectiveness of COVID-19 vaccines has become a major issue. The primary objective of this study is to examine the real-world effectiveness of COVID-19 vaccines based on secondary data acquired under normal circumstances in a real-world setting, to protect against treatment with invasive ventilation of pneumonia during January to April 2022, a period when Omicron was predominant. We conducted a nationwide test-negative case-control study. The case and control were matched with a ratio of 1:4 in terms of age, date of specimen collection, and hospital collection specimen and the odds ratio was calculated using conditional logistic regression. Overall, there was neither a distinction between mix-and-match regimens and homologous mRNA regimens against severe symptoms, nor was there a decline of the protective effect over the study period. The third and fourth dose boosters with ChAdOx1 nCoV-19 or mRNA vaccines provided high levels of protection against severe outcomes, approximately 87% to 100%, whereas two doses provided a moderate degree (70%). Thus, this study concludes that current national vaccine strategies provide favourable protective benefits against the Omicron variant. All Thais should receive at least two doses, while high-risk or vulnerable groups should be administered at least three doses.

Real-World Effectiveness of Mix-and-Match Vaccine Regimens against SARS-CoV-2 Delta Variant in Thailand: A Nationwide Test-Negative Matched Case-Control Study.

The objective of this study is to explore the real-world effectiveness of various vaccine regimens to tackle the epidemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant in Thailand during September-December 2021. We applied a test-negative case control study, using nationwide records of people tested for SARS-CoV-2. Each case was matched with two controls with respect to age, detection date, and specimen collection site. A conditional logistic regression was performed. Results were presented in the form vaccine effectiveness (VE) and 95% confidence interval. A total of 1,460,458 observations were analyzed. Overall, the two-dose heterologous prime-boost, ChAdOx1 + BNT162b2 and CoronaVac + BNT162b2, manifested the largest protection level (79.9% (74.0-84.5%) and 74.7% (62.8-82.8%)) and remained stable over the whole study course. The three-dose schedules (CoronaVac + CoronaVac + ChAdOx1, and CoronaVac + CoronaVac + BNT162b2) expressed very high degree of VE estimate (above 80.0% at any time interval). Concerning severe infection, almost all regimens displayed very high VE estimate. For the two-dose schedules, heterologous prime-boost regimens seemed to have slightly better protection for severe infection relative to homologous regimens. Campaigns to expedite the rollout of third-dose booster shot should be carried out. Heterologous prime-boost regimens should be considered as an option to enhance protection for the entire population.

Rapid method through routine data to evaluate real-world vaccine effectiveness against coronavirus disease 2019 (COVID-19) infection: lessons from Thailand.

The objective of this article is to draw lessons from the Thai experience in estimating vaccine effectiveness (VE) for coronavirus disease 2019 (COVID-19) based on routine service data. We found that a matched case-control design, using probability-based controls representing the varying vaccine coverage across the population over time, yielded a valid result for VE assessment. The proposed design has an advantage in its applicability drawing from the routine data monitoring system. Future studies that exercise other designs, such as test-negative and cohort studies, are recommended in order to compare and contrast the findings across different designs. To implement a continuous monitoring system on VE, the integration of data from different sources is needed. This requires long-term investment in the data monitoring system for the entire healthcare system.

Evaluation of a hospital-based injury surveillance system for monitoring road traffic deaths in Phuket, Thailand.

Objectives: The objective of this study was to evaluate and injury surveillance (IS) system's ability to monitor road traffic deaths and the coverage of road traffic injury and death surveillance in Phuket, Thailand. Methods: U.S. Centers for Disease Control and Prevention guidelines on surveillance system evaluation were used to qualitatively and quantitatively evaluate IS. Interviews with key stakeholders focused on IS's usefulness, simplicity, flexibility, acceptability, and stability. Active case finding of 2014 road traffic deaths in all paper and electronic hospital record systems was used to assess system sensitivity, positive predictive value, and data quality. Electronic data matching software was used to determine the implications of combining IS data with other provincial-level data sources (e.g., death certificates, electronic vehicle insurance claim system). Results: Evaluation results indicated that IS was useful, flexible, acceptable, and stable, with a high positive predictive value (99%). Simplicity was limited due to the burden of collecting data on all injuries and use of paper-based data collection forms. Sensitivity was low, with IS only identifying 55% of hospital road traffic death cases identified during active case finding; however, IS cases were representative of cases identified. Data accuracy and completeness varied across data fields. Combining IS with active case finding, death certificates, and the electronic vehicle insurance claim system more than doubled the number of road traffic death cases identified in Phuket. Conclusion: An efficient and comprehensive road traffic injury and death surveillance system is critical for monitoring Phuket's road traffic burden. The hospital-based IS system is a useful system for monitoring road traffic deaths and assessing risk behaviors. However, the complexity of data collection and limited coverage hinders the ability of IS to fully represent road traffic deaths in Phuket Province. Combining data sources could improve coverage and should be considered.

Data Reliability and Coding Completeness of Cancer Registry Information Using Reabstracting Method in the National Cancer Institute: Thailand, 2012 to 2014.

PURPOSE: Data quality is a core value of cancer registries, which bring about greater understanding of cancer distribution and determinants. Thailand established its cancer registry in 1986; however, studies focusing on data reliability have been limited. This study aimed to assess the coding completeness and reliability of the National Cancer Institute (NCI) hospital-based cancer registry, Thailand. METHODS: This study was conducted using the reabstracting method. We focused on seven cancer sites-the colon, rectum, liver, lung, breast, cervix, and prostate-registered between 2012 and 2014 in the NCI hospital-based cancer registry. Missing data were identified for coding completeness calculation among important variables. The agreement rate and κ coefficient were computed to represent data reliability. RESULTS: For reabstracting, we retrieved 957 medical records from a total of 5,462. These were selected using the probability proportional to size method, stratified by topology, sex, and registered year. The overall coding completeness of the registered and reabstracted data was 89.9% and 93.6%, respectively. In addition, the overall agreement rate among variables ranged from 84.7% to 99.6%, and κ coefficient ranged from 0.619 to 0.995. The misclassification among unilateral organs caused lower coding completeness and agreement rate of laterality coding. The completeness of current residency could be improved using the reabstracting method. The lowest agreement rate was found among various categories of diagnosis basis. Sex misclassification for male breast cancer was identified. CONCLUSION: The coding completeness and data reliability of the NCI hospital-based cancer registry met the standard in most critical variables. However, some challenges remain to improve the data quality. The reabstracting method could identify the critical points affecting the quality of cancer registry data.

Trends in Incidence of Two Major Subtypes of Liver and Bile Duct Cancer: Hepatocellular Carcinoma and Cholangiocarcinoma in Songkhla, Southern Thailand, 1989-2030.

BACKGROUND: The incidence of liver and bile duct cancer continues to rise, especially in Thailand. We aimed to project the trends in incidence of this rare but lethal cancer in southern Thailand in order to determine its future disease burden. METHODS: Gender-specific trends in age-standardized incidence rates per 100,000 person-years for hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) cases in Songkhla province of southern Thailand diagnosed between 1989 and 2013 were estimated and projected up to year 2030 using three different modeling techniques: a joinpoint model, an age-period-cohort model, and a modified age-period-cohort model. RESULTS: Of 2,676 liver and bile duct (LBD) cancer cases identified, 73% were males, 51% were aged between 50 and 69 years, and HCC (44.4%) was slightly more common than CCA (38.1%). The models all predicted an increase in the incidence rate of CCA up to 2025 for both sexes whereas the incidence of HCC is expected to decrease among males and stabilize among females. The incidence rates of HCC and CCA among males in 2030 could reach 6.7 and 9.4 per 100,000 person-years, respectively, whereas the expected rates of HCC and CCA among females are expected to be around 1.5 and 3.9 per 100,000 person-years, respectively. CONCLUSIONS: The incidence of cholangiocarcinoma is expected to increase in Songkhla and will contribute a larger proportion of LBD cancers in the future. Future public health efforts and research studies should focus on this increasing trend.

Estimation of the Incidence of Hepatocellular Carcinoma and Cholangiocarcinoma in Songkhla, Thailand, 1989-2013, Using Multiple Imputation Method.

PURPOSE: Histological specimens are not required for diagnosis of liver and bile duct (LBD) cancer, resulting in a high percentage of unknown histologies. We compared estimates of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) incidences by imputing these unknown histologies. MATERIALS AND METHODS: A retrospective study was conducted using data from the Songkhla Cancer Registry, southern Thailand, from 1989 to 2013. Multivariate imputation by chained equations (mice) was used in re-classification of the unknown histologies. Age-standardized rates (ASR) of HCC and CCA by sex were calculated and the trends were compared. RESULTS: Of 2,387 LBD cases, 61% had unknown histology. After imputation, the ASR of HCC in males during 1989 to 2007 increased from 4 to 10 per 100,000 and then decreased after 2007. The ASR of CCA increased from 2 to 5.5 per 100,000, and the ASR of HCC in females decreased from 1.5 in 2009 to 1.3 in 2013 and that of CCA increased from less than 1 to 1.9 per 100,000 by 2013. RESULTS: of complete case analysis showed somewhat similar, although less dramatic, trends. CONCLUSION: In Songkhla, the incidence of CCA appears to be stable after increasing for 20 years whereas the incidence of HCC is now declining. The decline in incidence of HCC among males since 2007 is probably due to implementation of the hepatitis B virus vaccine in the 1990s. The rise in incidence of CCA is a concern and highlights the need for case control studies to elucidate the risk factors.

Risk factors for measles in children younger than age 8 months: A case-control study during an outbreak in Guangxi, China, 2013.

BACKGROUND: Following a period (2009-2012) during which zero measles cases were reported, a measles outbreak occurred in 2013 in Bama County, Guangxi, China, that involved more than 100 children younger than age 8 months. We aimed to identify the pitfalls and risk factors while implementing the control measures. METHODS: An outbreak investigation and a case-control study was conducted among children younger than age 8 months. The serum specimens of the study subjects and their mothers were tested for measles immunoglobulin M and immunoglobulin G. RESULTS: The attack rate was 2.3/1,000 population. The median (interquartile range) age was 18.6 months (7.9-52.8 months). The coverage of 2-dose measles-containing vaccine was only 34%. The case-control study revealed 2 independent risk factors: low education level of main caregiver (odds ratio [OR], 2.86; 95% confidence interval [CI], 1.31-6.22) and visiting a hospital 7-21 days before the date of symptoms onset (OR, 9.84; 95% CI, 4.27-22.67). The population attributable fraction of the latter was 52.8%. The mothers of the cases had nonsignificantly higher levels of immunoglobulin M and were significantly more likely to have protective levels of immunoglobulin G than those of the controls. This suggests a reactive rather than protective role of the antibody to the child's infection. CONCLUSIONS: In a near-elimination but low measles-containing vaccine coverage community, supplementary immunization activities should be emphasized for children and women who are potential future mothers. The minimum age of measles-containing vaccine should be further reduced. Hospital measles transmission must also be strictly prevented.

A Population-Based Acute Meningitis and Encephalitis Syndromes Surveillance in Guangxi, China, May 2007-June 2012.

OBJECTIVES: Acute meningitis and encephalitis (AME) are common diseases with the main pathogens being viruses and bacteria. As specific treatments are different, it is important to develop clinical prediction rules to distinguish aseptic from bacterial or fungal infection. In this study we evaluated the incidence rates, seasonal variety and the main etiologic agents of AME, and identified factors that could be used to predict the etiologic agents. METHODS: A population-based AME syndrome surveillance system was set up in Guigang City, Guangxi, involving 12 hospitals serving the study communities. All patients meeting the case definition were investigated. Blood and/or cerebrospinal fluid were tested for bacterial pathogens using culture or RT-PCR and serological tests for viruses using enzyme-linked immunosorbent assays. Laboratory testing variables were grouped using factor analysis. Multinomial logistic regression was used to predict the etiology of AME. RESULTS: From May 2007 to June 2012, the annual incidence rate of AME syndrome, and disease specifically caused by Japanese encephalitis (JE), other viruses, bacteria and fungi were 12.55, 0.58, 4.57, 0.45 and 0.14 per 100,000 population, respectively. The top three identified viral etiologic agents were enterovirus, mumps virus, and JE virus, and for bacteria/fungi were Streptococcus sp., Cryptococcus neoformans and Staphylococcus sp. The incidence of JE and other viruses affected younger populations and peaked from April to August. Alteration of consciousness and leukocytosis were more likely to be caused by JE, bacteria and fungi whereas CSF inflammation was associated with bacterial/fungal infection. CONCLUSIONS: With limited predictive validity of symptoms and signs and routine laboratory tests, specific tests for JE virus, mumps virus and enteroviruses are required to evaluate the immunization impact and plan for further intervention. CSF bacterial culture cannot be omitted in guiding clinical decisions regarding patient treatment.

Success of a cervical cancer screening program: trends in incidence in songkhla, southern Thailand, 1989-2010, and prediction of future incidences to 2030.

BACKGROUND: Cervical cancer has been a leading female cancer in Thailand for decades, and has been second to breast cancer after 2007. The Ministry of Public Health (MoPH) has provided opportunistic screening with Pap smears for more than 30 years. In 2002, the MoPH and the National Health Security Office provided countrywide systematic screening of cervical cancer to all Thai women aged 35-60 years under universal health care coverage insurance scheme at 5-year intervals. OBJECTIVES: This study characterized the cervical cancer incidence trends in Songkhla in southern Thailand using joinpoint and age period cohort (APC) analysis to observe the effect of cervical cancer screening activities in the past decades, and to project cervical cancer rates in the province, to 2030. MATERIALS AND METHODS: Invasive and in situ cervical cancer cases were extracted from the Songkhla Cancer Registry from 1990 through 2010. Age standardized incidence rates were estimated. Trends in incidences were evaluated by joinpoint and APC regression models. The Norpred package was modified for R and was used to project the future trends to 2030 using the power of 5 function and cut trend method. RESULTS: Cervical cancer incidence in Songkhla peaked around 1998-2000 and then dropped by -4.7% per year. APC analysis demonstrated that in situ tumors caused an increase in incidence in early ages, younger cohorts, and in later years of diagnosis. CONCLUSIONS: Both joinpoint and APC analysis give the same conclusion in continuation of a declining trend of cervical cancer to 2030 but with different rates and the predicted goal of ASR below 10 or even 5 per 100,000 women by 2030 would be achieved. Thus, maintenance and improvement of the screening program should be continued. Other population based cancer registries in Thailand should analyze their data to confirm the success of cervical cancer screening policy of Thailand.

Signal detection for Thai traditional medicine: examination of national pharmacovigilance data using reporting odds ratio and reported population attributable risk.

Herbal containing medicine consumption has increased while the awareness of adverse drug reaction (ADR) was less than conventional medicine. Early detection of unexpected numbers of ADRs from herbal medicines' reports which are abnormal from the whole database needs quantification. Disproportionality analysis has been performed for signal detection by using reporting odds ratio (ROR) as measurement. The impact of having medicine as exposures in each ADR should be measured by using reported population attributable risks (RPAR). This study aimed to quantify the contribution of Thai traditional medicine (TTM) to ADR reports and to assess the association between TTMs and serious adverse drug reactions. Data were retrieved from the adverse drug reaction surveillance database, Thai-Food and Drug Administration from 2002 to 2013. Crude and adjusted RORs for each drug-ADR pair and RPARs were computed. TTM contributed only 0.001% of all serious ADRs reported. Out of 4208 TTM-ADR pairs were examined, three had the statistically significant RORs, namely Andrographis paniculata and anaphylactic shock (ROR 2.32, 95% CI 1.03, 5.21); green traditional medicine and Stevens-Johnson syndrome (ROR 13.04, 95% CI 5.4-31.51) and Derris scandens Benth and angioedema (ROR 2.71, 95% CI 1.05-6.95). Their RPARs ranged from 0.05% to 0.16%. We conclude that TTMs need more intensive surveillance.

Mekong Basin Disease Surveillance (MBDS): a trust-based network.

The Mekong Basin Disease Surveillance (MBDS) network was formally established in 2001 through a Memorandum of Understanding signed by six Ministers of Health of the countries in the Greater Mekong sub-region: Cambodia, China (Yunnan and Guangxi), Lao PDR, Myanmar, Thailand and Vietnam. The main areas of focus of the network are to: i) improve cross-border infectious disease outbreak investigation and response by sharing surveillance data and best practices in disease recognition and reporting, and by jointly responding to outbreaks; ii) develop expertise in epidemiological surveillance across the countries; and iii) enhance communication between the countries. Comprised of senior health officials, epidemiologists, health practitioners, and other professionals, the MBDS has grown and matured over the years into an entity based on mutual trust that can be sustained into the future. Other regions have started emulating the network's pioneering work. In this paper, we describe the development of MBDS, the way in which it operates today, and some of its achievements. We present key challenges the network has faced and lessons its members have learned about how to develop sufficient trust for health and other professionals to alert each other to disease threats across national borders and thereby more effectively combat these threats.

Prevalence and characteristics of dengue and chikungunya infections among acute febrile patients in Nong Khai Province, Thailand.

We conducted a cross sectional study at three hospitals of Nong Khai Province, Thailand to determine the prevalence and characteristics of dengue and chikungunya infection among patients who sought care. The study population was acute febrile patients who visited these hospitals during 1 August -31 October, 2010 who were aged 2-60 years and had clinical symptoms compatible with the case definition. Dengue and chikungunya cases were confirmed by an ELISA IgM titer or RT-PCR. We also reviewed surveillance data of dengue and chikungunya infections from 2003-2009. Of the 200 participants recruited into the study, 103 patients (51.5%) were confirmed to have acute dengue infection; dengue serotype 2 was the most prevalence serotype. The ages of confirmed dengue cases ranged from 2-37 years old. The distribution of cases showed that dengue morbidity tended to be clustered in adjacent areas, particularly in Mueang District. Only a small proportion of the patients uses mosquito repellant and had screens on their windows. One patient (0.5%) had laboratory confirmed chikungunya infection. She was from Rattanawapi District, an area where no chikungunya had been reported before. Since the disease varies by age and geographic location, increased awareness of health care workers and public health officers about the diseases in the area is needed for early detection of cases and to promote early prevention and control measures.

Evaluation of hepatitis A surveillance data and outbreak detection in Yunnan Province, China, from 2004 through 2009.

Hepatitis A outbreaks may be averted if detected early. The current study objectives were to evaluate the quality and timeliness of hepatitis A surveillance data from Yunnan Province, China, and to evaluate the sensitivity of the system for reporting outbreaks. The study period was from January 1, 2004 through December 31, 2009. Records from the National Infectious Diseases Surveillance System (NIDSS) were compared with those from local hospitals. The timeliness of case detecting, reporting and updating was also analyzed. The numbers of cases in a specific location during a moving time interval were computed to identify past outbreaks which were then validated against reported cases. The NIDSS received 38,095 reports during the study period; of which 6% were duplicates, and 26% had serological confirmation. The sensitivity and positive predictive value of cases were 96% and 98%, respectively. Time from onset to diagnosis remained constant over the 6-year period. Delays in reporting became shorter, and quality control of data improved over the period, but the timeliness of identifying duplicate records did not. Based on data from NIDSS, 9 outbreaks should have been reported, but only 3 were reported. The 3 reported outbreaks were shorter in duration than the 6 unreported ones, but the numbers of cases involved were not significantly different. Surveillance data needs improvement in updating timeliness. The system for outbreak detection and reporting needs to be improved.

Improving the health and mental health of people living with HIV/AIDS: 12-month assessment of a behavioral intervention in Thailand.

OBJECTIVES: We examined findings from a randomized controlled intervention trial designed to improve the quality of life of people living with HIV in Thailand. METHODS: A total of 507 people living with HIV were recruited from 4 district hospitals in northern and northeastern Thailand and were randomized to an intervention group (n = 260) or a standard care group (n = 247). Computer-assisted personal interviews were administered at baseline and at 6 and 12 months. RESULTS: At baseline, the characteristics of participants in the intervention and standard care conditions were comparable. The mixed-effects models used to assess the impact of the intervention revealed significant improvements in general health (B = 2.51; P = .001) and mental health (B = 1.57; P = .02) among participants in the intervention condition over 12 months and declines among those in the standard care condition. CONCLUSIONS: Our results demonstrate that a behavioral intervention was successful in improving the quality of life of people living with HIV. Such interventions must be performed in a systematic, collaborative manner to ensure their cultural relevance, sustainability, and overall success.

Antiretroviral therapy adherence among patients living with HIV/AIDS in Thailand.

The importance of antiretroviral therapy adherence for patients living with HIV/AIDS has been well documented. Despite this critical need, many do not follow prescribed regimens. To examine the barriers that lead to non-adherence, we used cross-sectional survey data from a randomized controlled intervention trial in northern and north-eastern Thailand. Of the 507 patients that were enrolled in the trial, we analyzed 386 patients on antiretroviral therapy in order to examine the barriers to adherence. In addition to demographic characteristics, depressive symptoms, physical health, access to care, social support, and internalized shame, HIV disclosure and family communication were examined. The correlation analysis revealed that adherence is significantly associated with internalized shame, access to care, depressive symptoms, and family communication. Based on the multiple logistic regression analysis, depressive symptoms, access to care, HIV disclosure, and family communication were significant predictors of adherence. Having depressive symptoms remains a significant barrier to adherence, while access to care, HIV disclosure, and family communication play important positive roles. Our findings underscore the critical importance of addressing these various challenges that can influence adherence to antiretroviral therapy.

Caregiver burden of family members of persons living with HIV in Thailand.

Caregivers of people living with HIV (PLH) in Thailand face tremendous caregiver burden. This study examines complex ways in which caregivers' mental health affects their levels of caregiver burden. This study uses data from 409 caregivers of PLH in northern and north-eastern Thailand. Multiple regression models were used to examine the predictors of caregiver burden. Depression was significantly associated with caregiver burden (P < 0.0001) and being HIV positive (P = 0.015). Inverse associations were observed between depression and quality of life (P < 0.0001) and caregiver burden and quality of life (P = 0.004). Social support had direct positive association with caregiver's quality of life (P < 0.0001). Our findings underscore the complex relationship between caregiver burden, depression and HIV-status. Interventions that address the caregiver burden are urgently needed.

Benefits of family and social relationships for Thai parents living with HIV.

Family and social relationships are important structural supports in Thailand that are likely to influence the health and mental health of persons living with HIV (PLH). Structural equation modeling examined these relationships among 409 PLH in two communities in Thailand. Latent variables were constructed for most outcomes and mediators, with adherence to antiretroviral (ARV) therapy, depression, and disclosure represented by single-item indicators. All models controlled for gender, age, and education. Disclosure was significantly and positively associated with ARV adherence, and to both family functioning and social support. Family functioning and social support were significantly related to the PLH's self-perceptions of health and mental health, as well as being significantly correlated with each other. Better family functioning was significantly associated with better quality of life, better perceived health, fewer symptoms of depression, and greater ARV adherence. Social support was significantly associated with better quality of life and fewer depressive symptoms. These results highlight the important role that an organized and structured family life and social support network can play in encouraging better health outcomes among PLH.

Stigma, social support, and depression among people living with HIV in Thailand.

BACKGROUND: People living with HIV/AIDS (PLWHA) in Thailand face tremendous challenges, including HIV-related stigma, lack of social support, and mental health issues such as depression. This study aims to examine complex relationships among demographics, HIV-related stigma, and social support and their impact on depression among PLWHA in Thailand. METHODS: This study uses data collected in northern and northeastern Thailand. A total of 408 PLWHA were recruited and interviewed in 2007. HIV-related stigma was measured by two subscales: "Internalized Shame" and "Perceived Stigma." Based on correlation analyses, hierarchical multiple regression models were used to examine the predictors of depression, social support, and HIV-related stigma, controlling for demographic characteristics. RESULTS: Correlational analysis revealed that depression was significantly associated with both dimensions of stigma: internalized shame and perceived stigma. Self-reported emotional social support was negatively associated with depression. We found that internalized shame and emotional social support were significant predictors of depression after controlling for gender, age, income, and education. CONCLUSIONS: HIV-related stigma has a negative impact on psychological wellbeing of PLWHA in Thailand, and emotional social support remains a protective factor against depression. Intervention developers and clinicians working with PLWHA may find it useful to incorporate the association between stigma and depression into their programs and treatments, and to address social support as a protective effect for the mental health of PLWHA.

Incidence of intussusception among children 0-5 years of age in Thailand, 2001-2006.

To provide baseline incidence data of intussusception among Thai children under 5 years old, outpatient and inpatient records from 2001 to 2006 from five hospitals were reviewed. 112 cases of intussusception were identified, confirmed by either ultrasonography (65%), radiology procedure (32%) or surgery (3%). Common presenting symptoms were vomiting, mucous bloody stool and fever. 50% of intussusceptions were ileocolic in location and 49% underwent surgery. Male to female ratio was 1.7:1 and 86% of cases were under 1 year of age. No deaths were reported. 89 of 112 cases were resident in the study catchment area, for an annual incidence of 19.70-47.83 and 4.36-11.44 per 100,000 children under 1 and 5 years of age, respectively. This is somewhat lower than other regional studies emphasising need to continue and enhance surveillance prior to starting a universal rotavirus vaccine program.