Sonographic Features of Uterine Arteriovenous Malformation: A Case Series.

Uterine arteriovenous malformation (AVM) is very rare but potentially life-threatening. Early and accurate diagnosis is the cornerstone of its management. The objective of this study is to encourage sonographers to become familiar with a variety of grayscale sonographic features, facilitating rapid recognition of the patterns and prompting them to apply color flow Doppler for a diagnosis of uterine AVM and possible further investigations or interventions. We present six cases of uterine AVM presenting with abnormal uterine bleeding at varying degrees of severity, from abnormal menstruation to life-threatening bleeding following curettage. All initially provided some clues of uterine AVM upon grayscale ultrasound, leading to the application of color Doppler flow to support a diagnosis, with confirmation using abdominal computer tomography angiography (CTA) in most cases, resulting in definitive treatment using uterine artery embolization or other interventions. Most importantly, this study provides various sonographic features of uterine AVM, such as appearances of small tubular structures, spongy patterns, a conceptive-product-like appearance, and spaghetti-like patterns. Hopefully, familiarity with these sonographic features can facilitate practitioners to make an early diagnosis, leading to proper further investigation and intervention, and to prevent serious complications from potentially being caused by this subtle but very serious disorder.

Comparisons of the Rates of Large-for-Gestational-Age Newborns between Women with Diet-Controlled Gestational Diabetes Mellitus and Those with Non-Gestational Diabetes Mellitus.

(1) Objectives: The primary objective is to compare the rate of large-for-gestational-age (LGA) between women with diet-controlled gestational diabetes mellitus (GDM) and those with non-GDM, and to assess whether or not diet-controlled GDM is an independent factor of LGA fetuses. The secondary objectives are to compare the rates of other common adverse pregnancy outcomes, such as preeclampsia, cesarean section rate, preterm birth, and low Apgar score, between pregnancies with diet-controlled GDM and non-GDM pregnancies. (2) Methods: A retrospective cohort study was conducted on singleton pregnancies, diagnosed with GDM and non-GDM between 24 and 28 weeks of gestation, based on a two-step screening test. The prospective database of the obstetric department was accessed to retrieve the records meeting the inclusion criteria, and full medical records were comprehensively reviewed. The patients were categorized into two groups, GDM (study group) and non-GDM (control group). The main outcome was the rate of LGA newborns, and the secondary outcomes included pregnancy-induced hypertension, preterm birth, cesarean rate, low Apgar scores, etc. (3) Results: Of 1364 recruited women, 1342 met the inclusion criteria, including 1177 cases in the non-GDM group and 165 (12.3%) in the GDM group. Maternal age and pre-pregnancy BMI were significantly higher in the GDM group. The rates of LGA newborns, PIH, and cesarean section were significantly higher in the GDM group (15.1% vs. 7.1%, p-value < 0.001; 7.8% vs. 2.6%, p-value = 0.004; and 54.5% vs. 41.5%, p-value = 0.002; respectively). On logistic regression analysis, GDM was not significantly associated with LGA (odds ratio 1.64, 95% CI: 0.97-2.77), while BMI and gender were still significantly associated with LGA. Likewise, GDM was not significantly associated with the rate of PIH (odds ratio: 1.7, 95% CI: 0.825-3.504), while BMI and maternal age were significantly associated with PIH, after controlling confounding factors. (4) Conclusions: The rates of LGA newborns, PIH, and cesarean section are significantly higher in women with diet-controlled GDM than those with non-GDM. Nevertheless, the rates of LGA newborns and PIH are not directly caused by GDM but mainly caused high pre-pregnancy BMI and advanced maternal age, which are more commonly encountered among women with GDM.

Change in Prevalence of Hepatitis B Virus Infection in Pregnant Women in the Last Two Decades in Thailand.

Objectives: In Thailand, there has been a strategy to prevent the mother-to-child transmission of HBV for over 30 years. However, there is still a lack of empirical evidence regarding the effectiveness of this strategy. This study aims to investigate the trends in the prevalence of HBV infection in pregnant women and to identify factors that may be associated with the prevalence of HBV infection in pregnant women. Patients and Methods: A maternal-fetal medicine database was accessed to retrieve the consecutive obstetric records of women giving birth at Chiang Mai University Hospital, Thailand, from January 2003 to December 2022. All women undergoing HBV tests with available results were included for an analysis of the trends and changes in the prevalence of maternal HBV infection. Also, the rates of infection in different age cohorts were compared. Results: During the study period, a total of 36,958 women were eligible for analysis. Overall, the prevalence of HBV infection in pregnant women was found to be 5.3% (1970 cases). Overall, HBV prevalence fell from 6.11% in 2003 to 3.15% in 2022. There was a significant reduction, especially in the adolescent group, decreasing from 8.26% in 2003 to 0% in 2022. In the reproductive age group, the prevalence significantly decreased from 6.41% to 2.01%. However, the prevalence in the elderly group was unchanged. The only significant risk factor was the years in the early timeline of the study period, presumably associated with previous HBV vaccination. Other factors, such as socioeconomic status, residential area, and being a private case, were not correlated with the prevalence of HBV. Conclusion: The prevalence of HBV infection in pregnant women has significantly decreased in the past two decades from 6.11% in 2003 to 3.15% in 2022. The percentage of reduction was very striking in the adolescent group, dropping from 8.6% in 2003 to 0.0% in 2022 or being nearly eradicated in the most recent years. Our results suggest that the overall prevalence of HBV infection among our pregnant women will probably be less than 1.0% in the near future.

Hepatitis B virus genotypes associated with pregnant women in Northern Thailand.

BACKGROUND: Mother-to-child transmission of hepatitis B virus (HBV) is the major route of transmission causing persistent infection. The prevalence of HBV infection and HBV genotypes found in different geographical areas varies from country to country. Therefore, this study was conducted to identify the HBV genotypes in HBV-infected pregnant women in Northern Thailand. METHODS: Stored blood samples that were collected from 145 HBsAg-positive pregnant women who gave birth at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand from 2017 to 2020 were analyzed. The partial nucleotide sequence of the S gene of HBV was amplified by nested PCR and sequenced. All sequences were analyzed phylogenetically together with the reference strains to define the HBV genotypes. RESULTS: A total of 31 blood samples from 145 HBsAg-positive pregnant women were positive for HBV by nested PCR. The detected HBV strains were identified as presumptive subgenotypes C1 (77.4%; 24/31), B9 (9.7%; 3/31), C2 (3.2%; 1/31), B2 (3.2%; 1/31), B4 (3.2%; 1/31), and presumptive B4/C2 recombinant subgenotype (3.2%; 1/31). CONCLUSIONS: The findings revealed that presumptive subgenotype C1 was the most common subgenotype circulating in pregnant women in Northern Thailand and accounted for 77.4% of cases, followed by presumptive subgenotypes B9, C2, B2, and B4. Furthermore, this study reported, for the first time in Thailand, the HBV genotypes and presumptive subgenotypes, particularly subgenotype B9 circulating in pregnant women.

Impacts of ß-thalassemia/hemoglobin E disease on pregnancy outcomes.

OBJECTIVE: To compare obstetric outcomes between women with ß-thalassemia/hemoglobin E (ß-thal/HbE) disease and those of low-risk pregnancies, and also between the two subgroups, ß-thal0 /HbE and ß-thal+ /HbE disease. METHODS: A retrospective cohort study was undertaken on pregnant women with ß-thal/HbE disease and low-risk pregnancies, which were randomly selected with a case-to-control ratio of 1:10. RESULTS: Pregnancies with ß-thal/HbE disease were identified in 0.19% of 59 152 pregnancies, including 104 women in the study group and 1040 women in the control group. The mean gestational age and mean birth weight were significantly lower in the study group. The prevalence of fetal growth restriction, preterm birth and low birth weight were significantly increased in the study group based on both univariate and multivariate analysis. The impacts were more striking in the ß-thal0 /HbE subgroup than in the ß-thal+ /HbE subgroup. The cesarean rate was significantly higher in the study group. No maternal death or serious complication was found in this cohort. CONCLUSION: Based on this cohort, the largest ever published, ß-thal/HbE disease is significantly associated with increased incidence of fetal growth restriction, preterm birth and low birth weight. The impacts were more pronounced in the ß-thal0 /HbE subgroup. Pregnancy may be relatively safer for women with ß-thal/HbE disease.

Possible Association between Genetic Diversity of Hepatitis B Virus and Its Effect on the Detection Rate of Hepatitis B Virus DNA in the Placenta and Fetus.

Background: The prevalence of HBV infection and HBV genotypes varies from country to country, and the role of HBV genotypes in the presence of HBV in the placenta and fetus has never been explored. This study was conducted to (1) identify HBV genotypes, and their frequencies, that infected Northern Thai pregnant women; (2) evaluate the association between HBV genotypes and the detection rate of HBV DNA in the placenta and fetus; (3) evaluate the association between specific mutations of the HBV genome and HBV DNA detection in placental tissue; and (4) identify the mutation of the HBV genome that might occur between maternal blood, placenta, and cord blood. Methods: Stored samples of the maternal blood, placental tissue, and cord blood that were collected from 145 HBsAg-positive pregnant Thai women were analyzed to identify HBV DNA. Results: Approximately 25% of infected mothers had fetal HBV DNA detection, including cases with concomitant HBV DNA detection in the placenta (77.3%). A total of 11.7% of cases with placental detection had no HBV DNA detection in the maternal blood, indicating that the placenta could be a site of HBV accumulation. Of the 31 HBV-positive blood samples detected by nested PCR, the detected strains were subgenotype C1 (77.4%), subgenotype B9 (9.7%), and subgenotype C2, B2, B4, and recombinant B4/C2 (3.2% for each). Genotype B had a trend in increased risk of placental HBV DNA detection compared to genotype C, with a relative risk of 1.40 (95% CI: 1.07-1.84). No specific point mutation had a significant effect on HBV DNA detection in placental tissue. Mutation of C454T tended to enhance HBV DNA detection in placental tissue, whereas T400A tended to have a lower detection rate. No mutation was detected in different sample types collected from the same cases. Conclusions: HBV DNA detection in the fetus was identified in approximately 25% of HBV-positive mothers, associated with the presence of HBV in the placenta in most cases. The placenta could possibly be a site of HBV accumulation. Subgenotype C1 was the most common subgenotype, followed by subgenotype B9. HBV genotype B possibly had a higher trend in intrauterine detection than HBV genotype C. Mutation is unlikely to occur during intrauterine exposure.

Trends in the Prevalence of Diabetes Mellitus in Pregnancy during the Past Two Decades in Northern Thailand.

Background: The prevalence of gestational diabetes mellitus (GDM) and pre-gestational diabetes mellitus (PDM) has increased dramatically in the past decade in all ethnic groups. The prevalence also varies markedly among different ethnic groups. Each ethnic group must have its own data about GDM/PDM for improvement in women's health care. We conducted this study with the main objective of assessing recent trends in the prevalence of PDM/GDM among pregnant women in the northern part of Thailand during the past two decades. The secondary objective is to identify the risk factors influencing the prevalence of DM in pregnancies. Patients and Methods: The maternal-fetal medicine database was accessed to retrieve consecutive obstetric records of women who gave birth in Chiang Mai University Hospital, Thailand, from January 2003 to December 2022. This is a 20-year study period of the same protocol of GDM screening policy, using the 50 g glucose challenge test as a screening test for the average risk group and the 100 g OGTT as a diagnostic test. The women were categorized into GDM, PDM and non-DM groups. Trends or percentage changes in the prevalence of GDM/PDM during the study period were evaluated. Risk factors related to GDM/PDM were identified. Results: Among 37,027 women who gave birth during the study period, the prevalence of DM in pregnancy was 11.4% (4223 cases), including 214 cases of PDM (0.6%) and 4009 cases of GDM (10.8%). The prevalence of PDM significantly increased from 0.3% in 2003 to 1.5% in 2022; also, the prevalence of GDM significantly increased, dramatically, from 3.4% in 2003 to 22.0% in 2022. The prevalence of GDM increased in recent years in all age groups (adolescent, reproductive and elderly groups), while that of PDM did not significantly change in the adolescent group during the study period. Maternal age and pre-pregnancy BMI significantly increased in the more recent years. Independent factors significantly associated with the prevalence of PDM/GDM include maternal age, pre-pregnancy BMI, higher socio-economic status, and urban areas of residence. Recent time is still an independent risk factor after adjustment for other known factors. Conclusions: Relatively, GDM and PDM are highly prevalent in the northern part of Thailand, and their prevalence continuously increased during the past two decades. The trend of increased prevalence was evident in all age groups. Increasing maternal age and pre-pregnancy BMI mainly contributed to the increase in the prevalence of GDM and PDM in recent years. Recent time is still an independent risk factor after adjustment for other known factors, indicating that some other unexplained risk factors are associated with the increase in prevalence of DM in recent years, possibly the increase in sedentary lifestyle. Modification of lifestyle, especially reducing pre-pregnancy BMI among reproductive women, may reduce the prevalence of DM in pregnancy.

Performance of Serum Quad Test in Screening for Fetal Down Syndrome in a Large-Scale Unselected Population in a Developing Country.

Objective: To assess the effectiveness of Quad test in the detection of Down syndrome (DS) in routine practice among a large-scale population and to compare the effectiveness of Quad test based on the Western reference model (WM) and that based on Thai reference model (TM). Methods: Quad test was performed on 42,769 pregnancies at 14-21 weeks. The fetal risk of DS derived from Quad test was automatically computed based on WM and used in evaluating the effectiveness. Also, the fetal risk was calculated based on the TM. Results: Of 39,740 women with complete follow-ups including 74 fetuses with DS, with WM, the detection and false positive rates were 81.1% and 7.2%, respectively, whereas the detection and false positive rates with TM were 87.8%, and 6.8%, respectively. According to ROC curves, the performance of Quad test based on TM was slightly but significantly better than that based on WM (AUC of 0.959 vs. 0.940, p = 0.001). Conclusion: Quad test is highly effective in service settings and suitable for developing countries and the effectiveness is even higher when based on ethnicity-specific reference model.

Popcorn Appearance of Severely Calcified Uterine Leiomyoma: Image-Pathological Correlation.

Calcified subserous leiomyoma is a rare benign tumor commonly seen in the postmenopausal age group. Cases with severely calcified degeneration all over the mass are extremely rare. It causes diagnostic confusion with the solid calcified adnexal mass and the large bladder calculi in the pelvis. We hereby present a case of heavily calcified subserous uterine leiomyoma in a 66-year-old postmenopausal woman. An X-ray of the abdomen and pelvis and CT scan showed a pelvic mass with scattered popcorn appearance in the pelvis, representing severely calcified discrete spots all over the mass. Sonographically, different from typical uterine leiomyomas which exhibit recurrent refractory shadowing patterns, our case showed heavy homogeneous acoustic shadow obscuring all structures beneath the mass surface, resulting in a suboptimal ultrasound examination. Accordingly, CT scans, which are usually not a primary tool for the diagnosis of uterine leiomyomas, are helpful to characterize the mass and identify their organ of origin. The case presented here was treated with a hysterectomy with bilateral oophorectomy and was post-operatively confirmed for severely calcified subserous leiomyomas.

An Unruptured True Aneurysm of the Uterine Artery during Pregnancy.

The antenatal diagnosis of an unruptured true aneurysm of the uterine artery is extremely rare and has never been reported, whereas pseudoaneurysms associated with previous trauma or cesarean section have been reported several times. True aneurysms occur when the artery or vessel weakens and bulges, sometimes forming a blood-filled sac. Nearly all cases of pelvic true aneurysms involved ovarian arteries which ruptured during the peripartum period. The case presented here is unique in terms of being an unruptured true aneurysm of the uterine artery with a first diagnosis during pregnancy at 32 weeks of gestation and the spontaneous development of thrombosis in the aneurysm in late pregnancy, documented at 37 weeks of gestation. The diagnosis of a true aneurysm of the uterine artery was based on, (1) a demonstration of the cystic mass located in proximity to the lower segment of the uterus with ultrasound characteristics of arterial flow in the mass, and (2) the occurrence in a woman who had no history of trauma or surgery in the pelvis. The finding during cesarean section confirmed the prenatal sonographic finding. The pregnancy ended with successful outcomes.

Cardiac rhabdomyoma as a possible new prenatal sonographic feature of Prader-Willi syndrome.

We describe a unique case of a pregnancy with fetal Prader-Willi syndrome (PWS). A 40-year-old pregnant woman prenatally presented with polyhydramnios, decreased fetal movements, fetal growth restriction with normal Doppler study, and fetal cardiac rhabdomyoma, a possible new sonographic markers for PWS, at 31 weeks of gestation. The newborn had hypotonia and feeding difficulty. Molecular genetic study showed a normal copy number of the 15q11.2-q13.1 chromosomal region but hypermethylation pattern of this region, indicating PWS. Other than the combination of polyhydramnios, fetal growth restriction, and decreased fetal movements, cardiac rhabdomyoma was detected and possibly associated with PWS. In conclusion, PWS should be listed in differential diagnoses if fetuses having the following perinatal factors: polyhydramnios, decreased fetal movements, and growth restriction. Finally, cardiac rhabdomyoma, observed in this case, might possibly be associated with PWS, although further studies to confirm are needed.

Effects of intrauterine exposure to hepatitis B virus in foetuses.

Foetal response to hepatitis B viral infection is still unknown. The mechanisms of persistent infection that occurs more often in mother-to-child transmission than adult transmission are also unclear. Various aspects of the environmental factors that accelerate or inhibit infection and the cytokine responses are associated with the persistence of infection. Several studies showed that the cytokine poor immune response in immaturity causes the persistence of the infection. However, some reports suggested that a mature immune response was the cause of this persistent infection. This review comprehensively summarized the reports from in vitro, in vivo as well as clinical reports regarding the responses of the foetuses of hepatitis B infected mothers to the micro-organism. The mechanism of more opportunities to be persistently infected via the mother-to-child transmission route is also summarized and discussed. Since there are limited clinical reports at this time, this review will provide evidence for future studies regarding the intrauterine infection mechanism and foetal response to hepatitis B virus to elucidate the mechanisms responsible for mother-to-child transmission. This understanding may lead to effective interventions to control mother-to-child hepatitis B infection in the future.

Prenatal Sonographic and Molecular Genetic Diagnosis of Popliteal Pterygium Syndrome.

Popliteal pterygium syndrome (PPS) is an extremely rare autosomal dominant disorder, characterized by the cleft palate with or without cleft lip, limbs abnormalities with highly characteristic features of popliteal webbing, syndactyly, and genital abnormalities and nail anomalies. Prenatal diagnosis of PPS has been extremely rare. We describe a unique case of fetal PPS at 20 weeks of gestation. The diagnosis of PPS was based on the ultrasound findings of bilateral popliteal webbings, extending from posterior aspects of the upper thighs through the lower legs, resulting in restriction in knee extension, bilateral equinovarus feet with syndactyly, ambiguous genitalia and the grooved lip. Anatomical structures were otherwise normal. Trio whole-exome sequencing revealed a de novo heterozygous IRF6 gene mutation in the fetus, confirming the diagnosis with PPS. In conclusion, popliteal webbing or combination of facial cleft or cleft variants and bilateral abnormal postures of the lower limbs is suggestive of PPS and genetic diagnosis should be warranted.

Hepatitis B Virus Infection in Pregnancy: Immunological Response, Natural Course and Pregnancy Outcomes.

This review aimed to provide an update on the impact of pregnancy on the natural course of hepatitis B virus (HBV) infection and also on the impact of HBV infection on adverse pregnancy outcomes, including mother-to-child transmission (MTCT). For the literature review, original research articles, review articles, and guidelines were narratively reviewed and comprehensively validated. The databases of PubMed, EMBASE, and CINAHL were carefully searched for articles in English on topics related to HBV infection, pregnancy, and vertical transmission from 1960 to May 2021. Immunological changes during pregnancy such as suppression of Th1 response and induction of Th2 immunity lead to an impaired immune reaction to HBV and stimulate viral activity along with the reduction of CD8 T cells to escape immune detection. The impact of pregnancy on the natural course of chronic HBV infection seems to be minimal, while pregnancy can increase morbidity and mortality in the case of advanced HBV hepatitis or cirrhosis. Importantly, hepatitis flare or alanine aminotransferase (ALT) flare can occur during pregnancy and is more common during the postpartum period due to the interaction between HBV and the immune response. Interestingly, the impact of HBV infection on adverse pregnancy outcomes is more serious than ever thought. Updated evidence indicates that pregnancies with chronic HBV infection increase the risk of preterm birth and gestational diabetes, especially in cases of positive hepatitis e antigen (HBeAg).

First trimester genetic sonogram for screening fetal Down syndrome: A population-based study.

OBJECTIVE: To evaluate the performance of first trimester sonomarkers in the detection of fetal Down syndrome among Thai pregnant women. MATERIALS AND METHODS: Pregnant women at 11-13+6 weeks' gestation underwent ultrasound examination for assessment of nuchal translucency (NT), nasal bone (NB), tricuspid regurgitation (TR), and abnormal ductus venosus (aDV) Doppler waveforms. The women were followed up for final outcomes. Fetal abnormalities other than trisomy 21 were excluded. The performances of each sonomarker and their combinations in predicting fetal Down syndrome were calculated. RESULTS: A total of 7820 pregnant women meeting the inclusion criteria were available for analysis, including 20 cases with fetal Down syndrome and 7800 unaffected cases. Of the four sonomarkers, NT, as a single sonomarker, had the highest detection rate (55.0% at a false positive rate of about 5%), whereas the remaining single sonomarkers had low detection rate (15-20%). The combination of all sonomarkers had the highest detection rate of 70% but the false positive rate was as high as 10.8%. The combination of NT and NB had a detection rate of 60% with an acceptable false positive rate of 6.9%, whereas the other combinations yielded relatively high false positive rates. CONCLUSION: The first trimester genetic sonogram in screening for Down syndrome among Asian women is acceptably effective and may be offered to some selected groups of the population. NT is the best sonomarker with a detection rate of 55% at 5% false positive rate and its combination with NB can improve performance with minimal increase in false positive rate.

New genetic and clinical evidence associated with fetal Beckwith-Wiedemann syndrome.

Early detection of Beckwith-Wiedemann syndrome (BWS) is very important since it is very useful regarding counseling of parents concerning the risk of developing embryonic tumors, selection of the mode of delivery due to potential adrenal cysts that might bleed during labor, prevention of neonatal hypoglycemia and even options of pregnancy termination in non-viable fetuses. This report describes the prenatal classic sonographic triad of fetal BWS (omphalocele, macrosomia, macroglossia) and other supporting findings (hepatomegaly, adrenal enlargement) as well as additional postnatal evidence. Also, it demonstrates new molecular genetic evidence potentially associated with the disease (the presence of a novel heterozygous c.358G>T variant of the CDKN1C gene). Importantly, we provide new evidence indicating that elevated levels of the four serum biomarkers (alpha-fetoprotein, beta-human gonadotropin, unconjugated estriol, and inhibin-A) in late first or early second trimester might be strongly suggestive of BWS which may facilitate early detection especially in cases of no obvious anomaly. In conclusion, this study emphasizes on early detection of BWS as early as at 14 weeks of gestation, based on the abnormal rise of the four serum biomarkers together with omphalocele. To the best of our knowledge, this is the earliest prenatal detection of BWS ever reported. Finally, we provide new molecular genetic evidence that is, potentially associated with BWS.

Hepatitis B Virus Infection in Pregnancy: An Update on Evidence-Based Management.

IMPORTANCE: Vertical hepatitis B virus (HBV) transmission is the important route of chronic HBV infection. Although infant immunoprophylaxis is effective, a significant number of infants still become infected, most are associated with intrauterine infection. New evidences support intrauterine treatment in cases of high risk. OBJECTIVE: The aim of this study was to review the current evidences and recommendations for management of HBV infection in pregnancy. EVIDENCE ACQUISITION: Original research articles, review articles, and guidelines were reviewed. RESULTS: The management can be summarized as follows: (1) all pregnant women should be screened for hepatitis B surface antigen (HBsAg) and antibody to HBsAg. High-risk HBsAg-negative pregnant women without immunity should be vaccinated during pregnancy. (2) HBsAg-positive pregnant women should undergo further workup for liver status and indicative factors for immunoprophylaxis failure. (3) Pregnant women should be treated with HBV DNA levels greater than 200,000 IU/mL or 6 log copies/mL. (4) Antiviral drug should be started around 28 to 32 weeks. The first-line drug is tenofovir disoproxil fumarate. (5) Delivery route should be chosen based only on obstetric indications. (6) Breastfeeding is not contraindicated because it does not increase the risk of transmission in neonates with HBV vaccine and immunoglobulin administration. (7) Neonates born to HBsAg-positive mothers should receive HBV vaccine and immunoglobulin after birth as soon as possible. (8) Follow-up of the mothers and neonates is important. Beware of hepatitis flare after birth and after antiretroviral drug discontinuation; alanine transaminase assessment every 1 to 3 months until 6 months is suggested. Also, the schedule of infant vaccination and follow-up of serologic testing at 9 to 12 months old is needed.

Genetic diversity of norovirus genogroup I, II, IV and sapovirus in environmental water in Thailand.

BACKGROUND: Enteric caliciviruses, including noroviruses (NoVs) and sapoviruses (SaVs) are the most significant pathogens associated with waterborne and foodborne outbreaks of nonbacterial acute gastroenteritis in humans worldwide. METHODS: In this study, 126 environmental water samples collected from 6 different sources in Chiang Mai, Thailand from November 2016 to July 2018 were examined for the presence of genogroups I, II, IV (GI, GII, GIV) NoVs and SaVs by using RT-nested PCR assays, genome sequencing, and phylogenetic analysis, RESULTS: Forty out of 126 (31.7%) water samples were positive for one or more caliciviruses throughout the years of study with high prevalence in winter. Among 126 tested specimens, 34 (27.0%), 30 (23.8%), 3 (2.4%), and 2 (1.6%) were positive for NoV GI, GII, GIV, and SaV, respectively. For NoV GI, 6 different genotypes were identified with the most predominant of GI.1 genotype (17 strains). In addition, 6 different genotypes of GII were detected with high prevalence of GII.17 (12 strains) and GII.2 (11 strains). It was interesting to note that our study reported the detection of NoV GIV for the first time in water samples in Thailand, and all were GIV.1 genotype. For SaV detection, only 2 water samples were positive for SaV GI. CONCLUSIONS: The data revealed heterogeneity and highly dynamic distribution of NoV GI, GII, GIV, and SaV in environmental water in Chiang Mai, Thailand, during the study period of 2016-2018.