The Surveillance of Acute Encephalitis Syndrome in Thailand, 2003-2019: A Perspective for Prevention and Control

Background

Acute encephalitis syndrome (AES) is an infection of the central nervous system with high case-fatality rates. Japanese encephalitis virus (JEV) is the most common vaccine preventable cause of AES in Asia and part of the Western Pacific. In 2003, the JE vaccine was introduced into Thailand's National Immunization Program and expanded to all provinces. This study reviews data from the national surveillance system on the incidence of AES, including Japanese encephalitis in Thailand to guide surveillance, control, and prevention strategies.

Materials and Methods

We collected data on all patients diagnosed with AES and reported to the Bureau of Epidemiology, Ministry of Public Health, Thailand, from 2003 to 2019.

Results

A total of 9566 AES patients and 266 death cases were reported during these 17 years. Six hundred and forty-two (6.7%) patients were JE with 16 deaths. The incidence of AES increased from 0.47-0.51-1.36 cases per 100,000 population with a preponderance of cases in adults. CFR reduced from 6.25% - 6.94% in 2003-2005 to 0.78% in 2019. AES cases occurred all year round in all the age groups with a male predilection JE vaccination coverage had reached 83% by 2019. The patients were mainly from the north-eastern region of Thailand.

Conclusion

Integrated surveillance regular monitoring, strengthening, and making immunization sustainable is required to improve and maintain progress toward JE control and prevention.

Measles seroprevalence in Thailand: are adolescents and young adults at risk of measles?

INTRODUCTION

During the last decade, measles has become an important re-emerging disease in Thailand. The objective of this study was to measure measles seroprevalence and its influencing factors and to plan for an improved vaccination program.

METHODS

A total of 600 participants aged between 9 months and 50 years were divided into seven groups those represent birth cohorts that experienced different measles vaccination policies. Participants' blood samples were obtained to measure measles immunoglobulin G (IgG) levels.

RESULTS

None of the participants in the 9-month age group had measles IgG levels beyond a protective level. Participants in the following age groups: 2 ½, 5-15, 16-29, 30-33, 34-40, and 41-50 years had 82% (95% confidence interval [CI] 73.3-90.7), 50% (95% CI 36.1-63.9), 52% (95% CI 42.3-62.7), 70% (95% CI 61.1-78.9), 88.8% (95% CI 84.1-93.5), and 98.8% (95% CI 96.4-100.0) measles seropositivity, respectively. The study did not find any significant factors affecting measles seropositivity.

CONCLUSION

Individuals aged 15-34 years are vulnerable to measles infections. Supplementary vaccination in special situations, including post-exposure prophylaxis during an outbreak among young adults or providing for high-risk occupations, such as healthcare personnel, should be encouraged.

Clinical manifestations of early childhood dengue virus infection in Thailand

INTRODUCTION

Clinical manifestations of dengue infection has a wide spectrum. This study aimed to describe and compare the clinical aspects of dengue infection in early childhood and those in older children.

MATERIALS AND METHODS

All dengue patients hospitalised at King Chulalongkorn Memorial Hospital, Bangkok, Thailand during 1987-2008 and aged 0-15 years were included. All parameters were compared between patients in two groups: aged 0-2 years and >2-15 years.

RESULTS

Of the 2,221 children who were diagnosed with dengue, 179 were children aged 0-2 years compared with 2,042 children aged >2-15 years. The early childhood group presented significantly more frequently with hepatomegaly, drowsiness, diarrhoea, rash, convulsions, splenomegaly, and unusual manifestations. Dengue fever (DF) was more common in the early childhood group and dengue haemorrhagic fever (DHF) was less common. The mortality rate of the early childhood group was 1.67%, which was significantly higher than that of the comparative group. Approximately 65% of study subjects were serologically proven to have primary infection, compared to 9.8% of older children.

CONCLUSIONS

Clinical manifestations of dengue infection in early childhood are different in some aspects from those of dengue infection in older children, and mortality is higher. To effectively prevent dengue infection morbidity and mortality in children, it is essential that clinicians correctly recognize and diagnose dengue infection, particularly in early childhood.

The burden of norovirus disease in children: a multi-country study in Chile, Brazil, Thailand and the Philippines

BACKGROUND

Noroviruses (NoVs) cause acute gastroenteritis (AGE) worldwide, affecting children in particular. We aimed to estimate the burden of disease due to NoV among children aged <6 years in Brazil, Chile, Philippines and Thailand.

METHODS

This was a prospective, hospital-based, observational study. Children were recruited over one year between 2014 and 2017. Four cohorts were analysed: community-acquired AGE outpatients and inpatients, nosocomial AGE inpatients, and asymptomatic outpatients. We collected demographic and clinical data, and a stool sample that was tested for NoV. Positive samples were tested for Rotavirus (RV) and NoV-genotyped. Disease severity was assessed by the Vesikari and modified Vesikari scores. Prevalence and incidence of NoV-AGE were estimated by cohort and country.

RESULTS

1637 participants yielded valid laboratory results. The proportion of NoV-positive cases was 23.8% (95% CI 20.8-27.2) in the outpatient cohort, 17.9% (15.0-21.3) in the hospital cohort, 21.4% (12.7-33.8) in the nosocomial cohort and 9.6% (6.9-13.2) in the asymptomatic cohort. Genotype GII.4 was predominant (58%). Less than 4% samples had RV coinfection. In general, NoV-positive subjects had more severe presentations than NoV-negative subjects.

CONCLUSIONS

NoV caused AGE with substantial burden throughout the studied settings, with higher relative frequency in Brazil where RV vaccination coverage is high.

Clinical features and antibiotic susceptibility of Salmonella gastroenteritis in children: A ten-year review

INTRODUCTION

Salmonella is a common organism, causing intestinal and extraintestinal infections among Thai children, especially infants, and leading to overwhelming antibiotic use.

MATERIALS AND METHODS

In this retrospective review, data collected during 2006-2015 from the medical charts of patients with evidence of infection, caused by any Salmonella serogroup or clinical form, were examined. We aimed to assess the clinical manifestations, antibiotic susceptibility, and antibiotic use in children with Salmonella gastroenteritis over the ten years' period.

RESULTS

A total of 419 patients had non-typhoidal Salmonella infection. Four-hundred (95.5%) patients were diagnosed with acute gastroenteritis, which was common in children aged <12 months (72.3%). The clinical features of patients with gastroenteritis included fever (74.5%), diarrhoea with bloody mucus (60.5%), watery diarrhoea (39.5%), and vomiting (19.8%). Serogroup B was most commonly detected in the stool specimens. The susceptibility of non-typhoidal Salmonella to ampicillin, norfloxacin, and co-trimoxazole was 36.3%, 98.0%, and 80.5%, respectively. Serogroup B was the most resistant strain, which was sensitive to ampicillin in only 21.6% of specimens, while it showed high susceptibility to norfloxacin and co-trimoxazole (98.1 and 84.0%, respectively). Third-generation cephalosporin and fluoroquinolone were most commonly prescribed.

CONCLUSIONS

Acute gastroenteritis is the most common form of Salmonella infection. Gastroenteritis caused by serogroup B is still the most common infection, which mostly occurs among infants under one year of age. The majority of stool specimens were still susceptible to antimicrobial agents, especially fluoroquinolone and cotrimoxazole; however, there was an overuse of antibiotics without proper indications.

Dengue associated haemophagocytic lymphohystiocytosis: An often-missed complication of a common infection

Hemophagocytic lymphohistiocytosis (HLH) is a severe and life-threatening condition causing multisystem involvement such as cytopenia, hepatosplenomegaly, and death. Dengue infection is one of the leading causes of HLH. We reviewed three cases of children at HRH Princess Maha Chakri Sirindhorn Medical Center, Faculty of Medicine, Srinakharinwirot University, Nakhon Nayok, Thailand, with dengue fever who subsequently developed HLH, based on the HLH-2004 diagnostic criteria. Following treatment with dexamethasone and intravenous immunoglobulin, there was a dramatic response including defervescence and improvement of cytopenia, hyperfibrinogenemia, and hyperferritinemia. Key features for diagnosis of dengue fever complicated by HLH include a history of prolonged fever exceeding seven days, splenomegaly, and worsening cytopenia. Early recognition and treatment are crucial for a successful outcome.

Post-licensure, phase IV, safety study of a live attenuated Japanese encephalitis recombinant vaccine in children in Thailand

BACKGROUND

Japanese encephalitis is a mosquito-borne viral disease endemic in most countries in Asia. A recombinant live, attenuated Japanese encephalitis virus vaccine, JE-CV, is licensed in 14 countries, including Thailand, for the prevention of Japanese encephalitis in adults and children.

METHODS

This was a prospective, phase IV, open-label, multicentre, safety study of JE-CV conducted from November 2013 to April 2015, to evaluate rare serious adverse events (AEs). JE-CV was administered to 10,000 healthy children aged 9months to <5years in Thailand as a primary (Group 1) or booster (Group 2) vaccination. Serious AEs (SAEs), including AEs of special interest, up to 60days after administration were evaluated. Immediate Grade 3 systemic AEs up to 30min after JE-CV administration were also described.

RESULTS

The median age of participants was 1.1years in Group 1 and 3.8years in Group 2. SAEs were reported in 204 (3.0%) participants in Group 1 and 59 (1.9%) participants in Group 2. Among a total of 294 SAEs in 263 participants, only three events occurring in two participants were considered related to vaccination. All three cases were moderate urticaria, none of which met the definition of AEs of special interest for hypersensitivity. AEs of special interest were reported in 28 (0.4%) participants in Group 1 and 4 (0.1%) participants in Group 2; none were considered related to vaccination. Febrile convulsion was the most frequently reported AE of special interest: 25 (0.4%) participants in Group 1; and 2 (<0.1%) in Group 2. There were no cases of Japanese encephalitis reported. No Grade 3 immediate systemic AEs were reported after any JE-CV vaccination.

CONCLUSIONS

Our study did not identify any new safety concerns with JE-CV and confirms its good safety profile. This study was registered on www.clinicaltrials.gov (NCT01981967; Universal Trial Number: U1111-1127-7052).

Serum Aminotransferases in Thai Children With Dengue Infection

BACKGROUND

Hepatic manifestations are one of the unusual manifestations of dengue infection.

OBJECTIVES

We conducted this study in order to study the pattern of serum aminotransferases and sequential changes before and after shock in Thai children with dengue infection.

PATIENTS AND METHODS

Children who were clinically and serologically diagnosed as dengue infection and were admitted to King Chulalongkorn Memorial Hospital during a peroid of one year were enrolled. They were clinically classified into a non-shock group and a shock group. The majority of serum aminotransferases including aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were obtained within a week after the onset of fever and until 3 days after shock in the shock group. Student t-test and median in boxplot form were used for statistical analysis.

RESULTS

We enrolled 127 children with a mean age of 7.6 ± 3.6 years. The incidence of abnormal AST and ALT levels was 97.4% and 50.0% in the shock group, and 91.8% and 44.9% in the non-shock group respectively. 29% and 15.4% of the patients in shock group and only 10.2% and 4.1% in non-shock group had the respective AST and ALT levels > 200 U/L. Serum aminotransferase levels were significantly higher in the shock group when compared to the non-shock group. AST tended to increase starting from one day before shock and continued to increase within a few days whereas ALT was less likely to be affected.

CONCLUSIONS

Elevated serum aminotransferases are a common finding in children with dengue infection and the levels of AST are higher than those of ALT. Patients with shock have significantly higher aminotransferase levels that increase up to 3 days after shock.

Early Onset Neonatal Sepsis Due to Salmonella enterica Serovar 4,5,12:i:-: A Case Report with Literature Review

The authors report a case of a 36-week male infant born via spontaneous vaginal delivery who developed Salmonella sepsis at HRH Princess Maha Chakri Sirindhorn Medical Center Srinakharinwirot University, Nakhon Nayok, Thailand. He was born to a mother without identifiable risk factors. On day 3, he developed fever tachycardia, lethargy, poor feeding and diarrhea prompting a sepsis evaluation. Blood and stool cultures were positive for S. enterica serovar 4,5,12:i:-. Therefore, Salmonella infection should be considered in the differential diagnosis of early onset neonatal sepsis (EOS) particularly in endemic areas.

Serum sodium levels do not predict recurrence of febrile seizures within 24 hours

BACKGROUND

Febrile seizures recur within 24 hours in around 16% of children. Some studies have demonstrated a significant correlation between serum sodium levels and recurrent febrile seizures.

AIM

To investigate whether the serum sodium level predicts recurrence of febrile seizures within 24 hours.

METHODS

The study was undertaken in children with febrile seizures in the period from January 2007 to December 2011. Retrospective data collected from medical records included age, gender, family history of febrile seizures, body temperature, duration of recognised fever and serum sodium levels.

RESULTS

315 children were diagnosed with febrile seizures with a mean (SD) age of 21.7 (12.5) months, and 181 (57.5%) were male. Forty-seven episodes of recurrent febrile seizures within 24 hours occurred in 39 children (12.4%). There was no significant difference in mean (SD) serum sodium levels between the 276 patients with single febrile seizures [134.94 (3.09) mmol/L] and those in whom febrile seizures recurred within 24 hours [134.49 (3.24) mmol/L]. A family history of febrile seizures was a significant predictive risk factor of recurrence within 24 hours (P < 0.05).

CONCLUSION

This study demonstrates that serum sodium levels do not predict the recurrence of febrile seizures within 24 hours.

DENGUE VIRUS VIRULENCE AND DISEASES SEVERITY

The dengue virus is the causative agent of a wide spectrum of clinical manifestations, ranging from mild acute febrile illness to classical dengue fever, dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS). DHF and DSS are the potentially fatal forms of dengue virus infection, which has become an intractable public health problem in many countries. The pathogeneses of DHF/ DSS are not clearly understood. One hypothesis concerning virus virulence and the immune enhancement hypothesis has been debated. Although dengue disease severity has been associated with evidence of genetic differences in dengue strains, virus virulence has been difficult to measure because of the lack of in vivo and in vitro models of the disease.

ASSOCIATION BETWEEN MANNOSE-BINDING LECTIN GENE POLYMORPHISMS AND SUSCEPTIBILITY TO DENGUE VIRUS INFECTION: A PRELIMINARY REPORT

Mannose-binding lectin (MBL) can bind with a wide range of pathogens and can activate through lectin pathway or enhances opsonophagocytosis. MBL is encoded by the MBL2 gene and single-nucleotide polymorphisms (SNPs) in the promoter and exon have functional effects on serum levels of MBL. MBL deficiency has been shown to predispose to infectious diseases. We assess whether or not, the variant MBL alleles are associated with susceptibility to dengue infection. Patients with confirmed dengue infection who were admitted to King Chulalongkorn Memorial Hospital during a calendar year were studied. Controls were patients without dengue infection. Deoxyribonucleic acid (DNA) was extracted from 50 μl of peripheral blood mononuclear cell (PBMC) using the DNA Blood Mini Kit. The SNPs in the promoter (-221 X/Y) and exon 1 (codon 54 A/B) of MBL2 gene were genotyped by using 2 separate cycling reactions of the TaqMan allele discrimination system. Serum levels of MBL were determined by double-antibody sandwich ELISA. Chi-square was used for statistical analysis. Serum MBL levels and genotypes were determined in 110 dengue patients (mean age 18.1 years; 62 males and 48 females) and 42 controls (mean age 25.8 years; males: females = 1:1). Our study showed that YB haplotype is associated with low serum levels of MBL. There was no association between MBL2 gene polymorphisms and susceptibility to dengue infection. The higher frequency of YB in dengue patients than in controls suggesting the likelihood of an association. Further studies are warranted.

Nasal carriage and antimicrobial susceptibility of Staphylococcus aureus among medical students at the HRH Princess Maha Chakri Sirindhorn Medical Center, Thailand: a follow-up study

OBJECTIVE

The objective of this study is to evaluate the patterns of nasal colonization of Staphylococcus aureus and its susceptibility patterns among medical students before and after their rotations in the hospital.

METHODS

Nasal swabs were obtained from 128 medical students for microbiological study and susceptibility testing prior to working in the hospital (the first), following the first rotation (the second) and at the end of the rotation schedule in the hospital (the last). The probable risk factors for nasal carriage were recorded for assessment.

RESULTS

S. aureus was isolated at the first, second and last swabs with colonization rates of 29.7%, 30.5% and 39.4%, respectively. The prevalence rate of colonization of S. aureus showed a statistically significant increase (P<0.05). There was a persistent colonization of S. aureus at the rate of 20.3%. No participants showed methicillin-resistant S. aureus. The susceptibility of S. aureus to erythromycin and clindamycin was 36.8%, 41% and 34% at the first, second and last swabs, respectively. There was no significant correlation between nasal carriage of S. aureus and its potential risk factors.

CONCLUSIONS

After clinical rotation in the hospital, the prevalence rate of asymptomatic nasal carriage of S. aureus increased and the S. aureus isolated has shown a relatively high resistance to erythromycin and clindamycin.

Nasal carriage and antimicrobial susceptibility of Staphylococcus aureus among medical students at the HRH Princess Maha Chakri Sirindhorn Medical Center, Thailand: a cross sectional study

OBJECTIVE

To determine the epidemiology of the nasal carriage of Staphylococcus aureus and its susceptibility pattern among preclinical medical students at the HRH Princess Maha Chakri Sirindhorn Medical Center, Srinakharinwirot University.

METHODS

Nasal swabs were taken from 128 preclinical medical students prior to working at the hospital. Susceptibility testing of S. aureus was performed using Kirby Bauer's disc diffusion method.

RESULTS

Of the 128 participants, 38/128 (29.7%; 95% confidence interval [CI]=21.8%, 37.6%) were carriers of S. aureus. No methicillin-resistant S. aureus was detected by the cefoxitin disk diffusion test. Resistance of S. aureus to erythromycin, clindamycin, tetracycline, chloramphenicol and fusidic acid was observed at the following rates: 63.2% (95% CI; 47.8%, 78.5%), 63.2% (95% CI; 47.8%, 78.5%), 34.2% (95% CI; 19.1%, 49.3%), 2.6% (95% CI; -2.5%, 7.7%) and 2.6% (95% CI; -2.5%, 7.7%), respectively. There was no statistically significant correlation between nasal carriage of S. aureus and possible risk factors.

CONCLUSIONS

The prevalence of asymptomatic nasal carriage of S. aureus was higher than reported by previous literature in Thailand, and S. aureus isolates exhibited relatively high resistance to erythromycin and clindamycin.

Successful medical treatment in a child with E. coli ESBL meningitis with acute communicating hydrocephalus and ventricular empyema: a case report

Extended-spectrum beta-lactamase (ESBL) producing organisms cause wide spectrum of diseases including urinary tract infection, cholangitis, intra-abdominal abscess or pneumonia but rarely meningitis. The present report a successful nonsurgical, medical treatment in a child with Escherichia coli ESBL meningitis with acute symptomatic communicating hydrocephalus and ventricular empyema. Incidence of infections from ESBL producing organisms are increasingly emerging and causing wide spectrum of illnesses which prompts for both aggressive medical and surgical intervention to prevent morbidity and mortality. Antimicrobial agents must be vigilantly utilized to prevent possible development of new highly-resistant organisms.

Heavy proteinuria following dengue hemorrhagic fever

We report a case of nephrotic range proteinuria with 24-hour urine protein level of 335.7 mg/kg/day which developed following dengue hemorrhagic fever. Due to prolonged hypoalbuminemia from renal loss, right pleural effusion persisted and required pleuracentesis. The patient did not have classical nephrotic syndrome. The proteinuria improved without specific treatment. A renal biopsy was not performed due to self-resolution of the proteinuria and azotemia. Heavy proteinuria is not a typical characteristic of dengue virus infection, therefore the pathophysiology of this nephropathy has not been well described to date.

Pneumococcal infections in high-risk and immunocompromised hosts

Streptococcus pneumoniae is an important cause of morbidity and mortality worldwide, it is responsible for invasive pneumococcal disease (IPD) (e.g. meningitis, bacteremic pneumonia and bacteremia) and non-IPD (e.g. pneumonia, acute otitis media, and sinusitis). IPD is preceded by nasopharyngeal colonization with high incidence of disease among young children, the elderly, persons with underlying medical conditions and immunocompromised hosts. The term "immunocompromised host" is generally applied to a variety of patients with various immune defects. The factors that contribute to the development of IPD include host immunity (specific and innate), genetic and environment. Specific defects in host responses to pneumococcal infections may due to very young age, deficiencies in levels of antibodies and complement factors, and splenic dysfunction. The combinations of these defects contribute to the increased rates of IPD. The immunocompromising and other conditions that predispose to pneumococcal disease were described.

Invasive pneumococcal infection in neonates: 3 case reports

Streptococcus pneumoniae is a rarely recognized cause of neonatal sepsis. We report invasive pneumococcal infection in three neonates. The infections were abrupt, severe, and rapidly progressive in two neonates with fatal outcome despite antibiotic therapy. There was no identifiable risk factor. Maternal colonization should be further studied.