Publications by authors named "Malinee Chittaganpitch"

Article Synopsis
  • - The Thai Department of Medical Sciences initiated a national external quality assessment (EQA) program to evaluate COVID-19 testing accuracy across 197 laboratories using inactivated SARS-CoV-2 samples.
  • - Most laboratories (93%) reported accurate results, although some faced issues, with false negatives mostly linked to low viral loads and two key error causes identified: RNA contamination and poor-quality RNA extraction.
  • - This EQA approach could guide other countries in setting up their own programs for better laboratory accuracy, emphasizing that such national schemes can be more cost-effective and sustainable than commercial alternatives.
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Background: Pneumonia remains the leading cause of death among children <5 years of age beyond the neonatal period in Thailand. Using data from the Pneumonia Etiology Research for Child Health (PERCH) Study, we provide a detailed description of pneumonia cases and etiology in Thailand to inform local treatment and prevention strategies in this age group.

Methods: PERCH, a multi-country case-control study, evaluated the etiology of hospitalized cases of severe and very severe pneumonia among children 1-59 months of age.

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Background: Seasonal influenza vaccination uptake among young children in Thailand is low despite national recommendation for vaccination. We implemented a knowledge, attitude/perception, and practice survey to understand determinants of influenza vaccination in children aged six months to two years.

Methods: Using a cross-sectional design, we interviewed caregivers of 700 children in seven hospitals using a structured questionnaire to collect information on caregivers' and children's demographic characteristics, and caregivers' knowledge of influenza illness and national vaccine recommendation, attitude/perception toward influenza vaccine, and information sources.

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Background: We compared influenza antibody titers among vaccinated and unvaccinated pregnant and non-pregnant women.

Methods: During 1st June- 30th September 2018, four groups of cohort participants-vaccinated pregnant, unvaccinated pregnant, vaccinated non-pregnant, and unvaccinated non-pregnant women were selected by matching age, gestational age, and the week of vaccination. Serum antibody titers against each strain of 2018 Southern Hemisphere inactivated trivalent influenza vaccine (IIV3) were assessed by hemagglutination inhibition (HI) assay on Day 0 (pre-vaccination) and Day 28 (one month post-vaccination) serum samples.

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Background: Influenza illness burden is substantial, particularly among young children, older adults, and those with underlying conditions. Initiatives are underway to develop better global estimates for influenza-associated hospitalizations and deaths. Knowledge gaps remain regarding the role of influenza viruses in severe respiratory disease and hospitalizations among adults, particularly in lower-income settings.

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Background: Human metapneumovirus is a common virus associated with acute lower respiratory infections (ALRIs) in children. No global burden estimates are available for ALRIs associated with human metapneumovirus in children, and no licensed vaccines or drugs exist for human metapneumovirus infections. We aimed to estimate the age-stratified human metapneumovirus-associated ALRI global incidence, hospital admissions, and mortality burden in children younger than 5 years.

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Article Synopsis
  • This study focused on the causes of severe acute respiratory infections (SARI) in adults across six countries, using advanced testing methods to identify multiple pathogens.
  • Researchers enrolled 2,388 SARI patients and 1,135 asymptomatic adults, finding that 76% of SARI patients had at least one detectable pathogen, commonly Haemophilus influenzae and Streptococcus pneumoniae.
  • The analysis suggested that specific pathogens, including various strains of influenza and RSV, significantly contributed to SARI cases, highlighting the potential benefits of flu vaccination and the need for RSV vaccine development to lessen SARI prevalence.
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Background: External quality assessments (EQAs) for the molecular detection of respiratory syncytial virus (RSV) are necessary to ensure the provision of reliable and accurate results. One of the objectives of the pilot of the World Health Organization (WHO) Global RSV Surveillance, 2016-2017, was to evaluate and standardize RSV molecular tests used by participating countries. This paper describes the first WHO RSV EQA for the molecular detection of RSV.

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Article Synopsis
  • The Thailand Ministry of Public Health and the US CDC launched a surveillance program in 2010 to identify causes of severe pneumonia across 30 hospitals in 17 provinces.
  • More than 60% of tested cases from December 2010 to December 2015 identified a potential etiology, with respiratory syncytial virus being the most common pathogen, particularly in children under 5.
  • The surveillance system also tested for MERS-CoV but found no cases, contributing to overall knowledge and preparedness for pneumonia outbreaks.
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Background: Human respiratory syncytial virus (RSV) causes illnesses among all age groups and presents a burden to healthcare services. To better understand the epidemiology and seasonality of RSV in different geographical areas, the World Health Organization (WHO) coordinated a pilot initiative to access the feasibility of establishing RSV surveillance using the existing Global Influenza Surveillance and Response System (GISRS) platform.

Objectives: To describe and compare RSV and influenza seasonality in countries in the northern andsouthern temperate, and tropics during the period January 2017 to April 2019.

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We report two cases of coronavirus disease 2019 (COVID-19) in travellers from Wuhan, China to Thailand. Both were independent introductions on separate flights, discovered with thermoscanners and confirmed with RT-PCR and genome sequencing. Both cases do not seem directly linked to the Huanan Seafood Market in Hubei but the viral genomes are identical to four other sequences from Wuhan, suggesting early spread within the city already in the first week of January.

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Diabetes mellitus (DM) patients are at an increased risk of complications following influenza-virus infection, seasonal vaccination (SV) is recommended. However, SV with trivalent influenza vaccine (TIV) can induce antibody and type-I interferon (IFN) responses, and the effect of anti-DM treatment on these responses is incompletely understood. We evaluated the antibody response and IFN-α expression in individuals with and without type 2 DM (T2DM) following SV, and examined the effects on anti-DM treatment.

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Background: On-line hemodiafiltration (HDF) clears more azotemic toxins compared to high-flux hemodialysis (HD). The response to vaccination is impaired in dialysis patients. We wished to determine whether the immune responses to influenza vaccine in dialysis patients treated by HDF were stronger than those treated by HD.

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Background: Information on the burden, characteristics and seasonality of non-influenza respiratory viruses is limited in tropical countries.

Objectives: Describe the epidemiology of selected non-influenza respiratory viruses in Thailand between June 2010 and May 2014 using a sentinel surveillance platform established for influenza.

Methods: Patients with influenza-like illness (ILI; history of fever or documented temperature ≥38°C, cough, not requiring hospitalization) or severe acute respiratory infection (SARI; history of fever or documented temperature ≥38°C, cough, onset <10 days, requiring hospitalization) were enrolled from 10 sites.

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Background: Self-collection of nasal swabs could improve the timeliness of influenza virus detection in older adults.

Objectives: Measure the acceptability, adequacy, timeliness, and validity of self-collected nasal swabs among adults >65 years in Thailand.

Methods: Our evaluation consisted of two parts: a one-month study among randomly selected, community-dwelling older adults to simulate community-based surveillance for acute respiratory infections (ARI); and a clinic study of older adults with ARI to evaluate the sensitivity and specificity of self-collected nasal swabs for influenza virus infection compared with healthcare worker (HCW)-collected nasal and nasopharyngeal swabs.

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Background: The global burden of pediatric severe respiratory illness is substantial, and influenza viruses contribute to this burden. Systematic surveillance and testing for influenza among hospitalized children has expanded globally over the past decade. However, only a fraction of the data has been used to estimate influenza burden.

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Background: Each year, an influenza B strain representing only one influenza B lineage is included in the trivalent inactivated influenza vaccine (IIV3); a mismatch between the selected lineage and circulating viruses can result in suboptimal vaccine effectiveness. We modeled the added potential public health impact of a quadrivalent inactivated influenza vaccine (IIV4) that includes strains from both influenza B lineages compared to IIV3 on influenza-associated morbidity and mortality in Thailand.

Methods: Using data on the incidence of influenza-associated hospitalizations and deaths, vaccine effectiveness, and vaccine coverage from the 2007-2012 influenza seasons in Thailand, we estimated rates of influenza-associated outcomes that might be averted using IIV4 instead of IIV3.

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Background: Clinical practice guidelines for influenza have been implemented to maximise the appropriate use of empirical oseltamivir; however, good predictive values are required.

Methods: Between October 2011 and September 2013, children aged < 15 years who presented at the Bamrasnaradura Infectious Diseases Institute with an influenza-like illness plus either (i) pneumonia or (ii) being in a higher risk group for influenza complications were prospectively enrolled. Respiratory specimens were taken for real-time polymerase chain reaction testing (RT-PCR).

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Background: Influenza-associated mortality in subtropical or tropical regions, particularly in developing countries, remains poorly quantified and often underestimated. We analyzed data in Thailand, a middle-income tropical country with good vital statistics and influenza surveillance data.

Methods: We obtained weekly mortality data for all-cause and three underlying causes of death (circulatory and respiratory diseases, and pneumonia and influenza), and weekly influenza virus data, from 2006 to 2011.

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Influenza epidemiology differs substantially in tropical and temperate zones, but estimates of seasonal influenza mortality in developing countries in the tropics are lacking. We aimed to quantify mortality due to seasonal influenza in Thailand, a tropical middle-income country. Time series of polymerase chain reaction-confirmed influenza infections between 2005 and 2009 were constructed from a sentinel surveillance network.

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During February 2013-March 2015, a total of 602 human cases of low pathogenic avian influenza A(H7N9) were reported; no autochthonous cases were reported outside mainland China. In contrast, since highly pathogenic avian influenza A(H5N1) reemerged during 2003 in China, 784 human cases in 16 countries and poultry outbreaks in 53 countries have been reported. Whether the absence of reported A(H7N9) outside mainland China represents lack of spread or lack of detection remains unclear.

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Objective: Limited data were available to guide management, counseling, and/or diagnostic investigation among children presenting with influenza-like illness (ILI). During a recent period of high influenza activity, we wished to determine the frequency, outcomes, and factors associated with influenza infection among children presenting with ILI.

Material And Method: During September and October 2010, children presenting with ILI were enrolled.

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Most neutralizing antibodies elicited during influenza virus infection or by vaccination have a narrow spectrum because they usually target variable epitopes in the globular head region of hemagglutinin (HA). In this study, we describe a human monoclonal antibody (HuMAb), 5D7, that was prepared from the peripheral blood lymphocytes of a vaccinated volunteer using the fusion method. The HuMAb heterosubtypically neutralizes group 1 influenza A viruses, including seasonal H1N1, 2009 pandemic H1N1 (H1N1pdm) and avian H9N2, with a strong hemagglutinin inhibition activity.

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Background: Pandemic influenza A(H1N1)pdm09 emerged in Thailand in 2009. A prospective longitudinal adult cohort and household transmission study of influenza-like illness (ILI) was ongoing in rural Thailand at the time of emergence. Symptomatic and subclinical A(H1N1)pdm09 infection rates in the cohort and among household members were evaluated.

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