Pichamon Sittikul

Dr. Pichamon Sittikul


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 September 2022 in Viruses
Verified
Journal Article
Open access
PDF file
Harapan HarapanHarapan Harapan
Harapan Harapan
Youdiil OphinniYoudiil Ophinni
Youdiil Ophinni
DMDewi Megawati
Dewi Megawati
Andri FrediansyahAndri Frediansyah
Andri Frediansyah
SMSukamto Salang Mamada
Sukamto Salang Mamada
Malik SallamMalik Sallam
Malik Sallam
The 2022 multi-country monkeypox outbreak in humans has brought new public health adversity on top of the ongoing coronavirus disease 2019 (COVID-19) pandemic. The disease has spread to 104 countries throughout six continents of the world, with the highest burden in North America and Europe. The etiologic agent, monkeypox virus (MPXV), has been known since 1959 after isolation from infected monkeys, and virulence among humans has been reported since the 1970s, mainly in endemic countries in West and Central Africa. However, the disease has re-emerged in 2022 at an unprecedented pace, with particular concern on its human-to-human transmissibility and community spread in non-endemic regions. As a mitigation effort, healthcare workers, public health policymakers, and the general public worldwide need to be well-informed on this relatively neglected viral disease. Here, we provide a comprehensive and up-to-date overview of monkeypox, including the following aspects: epidemiology, etiology, pathogenesis, clinical features, diagnosis, and management. In addition, the current review discusses the preventive and control measures, the latest vaccine developments, and the future research areas in this re-emerging viral disease that was declared as a public health emergency of international concern.

10 May 2021 in Pathogens
Verified
Journal Article
Open access
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NTNipa Thammasonthijarern
Nipa Thammasonthijarern
NKNathamon Kosoltanapiwat
Nathamon Kosoltanapiwat
WNWarisa Nuprasert
Warisa Nuprasert
PSPichamon Sittikul
Pichamon Sittikul
PSPimolpachr Sriburin
Pimolpachr Sriburin
SCSupawat Chatchen
Supawat Chatchen
Hand, foot, and mouth disease (HFMD) is a contagious childhood illness and annually affects millions of children aged less than 5 years across the Asia–Pacific region. HFMD transmission mainly occurs through direct contact (person-to-person) and indirect contact with contaminated surfaces and objects. Therefore, public health measures to reduce the spread of HFMD in kindergartens and daycare centers are essential. Based on the guidelines by the Department of Disease Control, a school closure policy for HFMD outbreaks wherein every school in Thailand must close when several HFMD classrooms (more than two cases in each classroom) are encountered within a week, was implemented, although without strong supporting evidence. We therefore conducted a prospective cohort study of children attending five kindergartens during 2019 and 2020. We used molecular genetic techniques to investigate the characteristics of the spreading patterns of HFMD in a school-based setting in Bangkok, Thailand. These analyses identified 22 index cases of HFMD (symptomatic infections) and 25 cases of enterovirus-positive asymptomatic contacts (24 students and one teacher). Enterovirus (EV) A71 was the most common enterovirus detected, and most of the infected persons (8/12) developed symptoms. Other enteroviruses included coxsackieviruses (CVs) A4, CV-A6, CV-A9, and CV-A10 as well as echovirus. The pattern of the spread of HFMD showed that 45% of the subsequent enteroviruses detected in each outbreak possessed the same serotype as the first index case. Moreover, we found a phylogenetic relationship among enteroviruses detected among contact and index cases in the same kindergarten. These findings confirm the benefit of molecular genetic assays to acquire accurate data to support school closure policies designed to control HFMD infections.

6 July 2023 in Biosafety and Health
Verified
Journal Article
Open access
PSPichamon Sittikul
Pichamon Sittikul
PSPimolpachr Sriburin
Pimolpachr Sriburin
JRJittraporn Rattanamahaphoom
Jittraporn Rattanamahaphoom
WNWarisa Nuprasert
Warisa Nuprasert
NTNipa Thammasonthijarern
Nipa Thammasonthijarern
SCSupawat Chatchen
Supawat Chatchen
• Scientific question: Hand, foot, and mouth disease (HFMD) is a contagious disease that mainly affects young children in the Asia–Pacific region. The viral transmission can occur through direct contact with nose and throat secretions, surfaces, fomites and the environment. Moreover, children’s school toys may serve an important role in HFMD surface-to-hand transmission. Heat inactivation can be an alternative to control HFMD transmission at schools. • Evidence before this study: Stability and heat inactivation of enteroviruses on different surfaces have been investigated in previous studies. However, studies regarding entervirus-A71 (EV-A71) and coxsackievirus A16 (CVA16) on children’s school toy surfaces have been rarely reported. • New findings: In this study, we showed that the infectivity of EV-A71 and CVA16 declined within a few hours on all three surfaces, whereas the viral RNA could be detected for up to 28 days. In both assays, viral stability was higher on wood than on the other surfaces. Meanwhile, heat inactivation at 60°C for 15 min, which can be repeatable without damaging toys, was sufficient to completely inactivate both enterovirus serotypes. • Significance of the study: Results of the study clearly demonstrated the prolonged persistence of enteroviruses on commonly encountered surfaces, highlighting the potential of indirect spread of these viruses among children. The heat inactivation is an applicable way for controlling the spread of pathogens in school environments, including complimented disinfection programs which normally required detergents and water.

10 September 2021 in Viruses
Verified
Journal Article
Open access
PDF file
PSPimolpachr Sriburin
Pimolpachr Sriburin
PSPichamon Sittikul
Pichamon Sittikul
NKNathamon Kosoltanapiwat
Nathamon Kosoltanapiwat
SSSalin Sirinam
Salin Sirinam
WAWatcharee Arunsodsai
Watcharee Arunsodsai
SCSupawat Chatchen
Supawat Chatchen
Zika virus (ZIKV) is the mosquito-transmitted virus that the WHO declared a Public Health Emergency of International Concern in 2016 due to the consequence of microcephaly from infected pregnancies. The incidence of Zika infection has been unclear in many countries because most infected people have nonspecific febrile illnesses. This study’s aim is to investigate the incidence of symptomatic Zika virus infections from the archived samples of a dengue cohort study of children in central Thailand from 2006 to 2009. We performed Zika NS1 immunoglobulin (Ig)G enzyme-linked immunosorbent assay (ELISA) screening to identify symptomatic Zika infections in paired acute/convalescent serum samples. Symptomatic Zika infections were confirmed by reverse transcription polymerase chain reactions (RT-PCR) of acute serum samples. The comparison of the Zika NS1 IgG ELISA results between acute and convalescent samples showed 290/955 (30.4%) seropositive cases. Zika RT-PCR results were positive in 28 febrile cases (15 females, 13 males). Zika RT-PCR showed that symptomatic Zika infection occurred in children aged 4–11 years in Ratchaburi province, Thailand (2007–2009, first case in April 2007), and the symptomatic Zika:dengue infection ratio was 28 Zika:394 dengue (1:14). Phylogenetic analysis showed that all Zika viruses were of Asian lineage. Zika NS1 IgG ELISA identified Zika-infected patients and showed a low Zika:dengue ratio.

20 June 2023 in Viruses
Verified
Journal Article
Open access
PDF file
PSPichamon Sittikul
Pichamon Sittikul
EBElizabeth M. Batty
Elizabeth M. Batty
PYPrasert Yodsawat
Prasert Yodsawat
JNJiratchaya Nuanpirom
Jiratchaya Nuanpirom
NKNathamon Kosoltanapiwat
Nathamon Kosoltanapiwat
JTJanjira Thaipadungpanit
Janjira Thaipadungpanit
Human enterovirus causes various clinical manifestations in the form of rashes, febrile illness, flu-like illness, uveitis, hand–foot–mouth disease (HFMD), herpangina, meningitis, and encephalitis. Enterovirus A71 and coxsackievirus are significant causes of epidemic HFMD worldwide, especially in children aged from birth to five years old. The enterovirus genotype variants causing HFMD epidemics have been reported increasingly worldwide in the last decade. We aim to use simple and robust molecular tools to investigate human enteroviruses circulating among kindergarten students at genotype and subgenotype levels. With the partial 5′-UTR sequencing analysis as a low-resolution preliminary grouping tool, ten enterovirus A71 (EV-A71) and coxsackievirus clusters were identified among 18 symptomatic cases and 14 asymptomatic cases in five kindergartens in Bangkok, Thailand, between July 2019 and January 2020. Two occurrences of a single clone causing an infection cluster were identified (EV-A71 C1-like subgenotype and coxsackievirus A6). Random amplification-based sequencing using MinION (Oxford Nanopore Technology) helped identify viral transmission between two closely related clones. Diverse genotypes co-circulating among children in kindergartens are reservoirs for new genotype variants emerging, which might be more virulent or better at immune escape. Surveillance of highly contagious enterovirus in communities is essential for disease notifications and controls.

Verified
Journal Article
Open access
PDF file
PSPichamon Sittikul
Pichamon Sittikul
PSPimolpachr Sriburin
Pimolpachr Sriburin
JRJittraporn Rattanamahaphoom
Jittraporn Rattanamahaphoom
KLKriengsak Limkittikul
Kriengsak Limkittikul
CSChukiat Sirivichayakul
Chukiat Sirivichayakul
SCSupawat Chatchen
Supawat Chatchen
Zika virus (ZIKV) is a mosquito-borne flavivirus that has recently emerged as a global health threat. The rise in ZIKV infections has driven an increased incidence of neonates born with microcephaly or other neurological malformations. Therefore, screening for ZIKV infection can considerably impact pregnant women, especially during the first trimester. The majority of ZIKV infections are mild or asymptomatic, and clinical diagnosis is inaccurate. Moreover, given the high level of cross-reactivity among flaviviruses, serological approaches to distinguish ZIKV from dengue virus (DENV) infections are complicated. We used the combination of DENV and ZIKV nonstructural protein 1 (NS1) IgG enzyme-linked immunosorbent assay (ELISA) and ZIKV NS1 blockade-of-binding (BOB) ELISA to test the convalescent sera of non-flavivirus, primary DENV, secondary DENV, and ZIKV infections. Our findings indicate that primary testing using a ZIKV NS1 IgG ELISA, the test of choice for large-scale ZIKV serosurvey studies, provided relatively high sensitivity. Moreover, the confirmation of positive ELISA results using the ZIKV NS1 BOB ELISA increased average specificity to 94.59% across serum samples. The combined use of two simple ELISAs for ZIKV serosurveys and the monitoring of ZIKV infection during pregnancy can elucidate the epidemiology, pathogenesis, and complications of ZIKV in DENV-endemic areas.