Virus diversity and an outbreak of group C rotavirus among infants and children with diarrhea in Maizuru city, Japan during 2002-2003

A total of 236 fecal specimens collected from infants and children with gastroenteritis in Maizuru city, Japan from July 2002 to June 2003, were tested for the presence of rotaviruses, noroviruses, sapoviruses, astroviruses, and adenoviruses by RT-PCR, PAGE, RPHA, and latex agglutination methods. Among diarrheal viruses detected, group A rotavirus was the most prevalent (32.2%; 76 of 236) followed by norovirus GII (21.2%; 50 of 236), group C rotavirus (10.2%; 24 of 236), adenovirus (3.8%; 9 of 236), sapovirus (2.5%; 6 of 236), astrovirus (1.3%; 3 of 236), and norovirus GI (0.8%; 2 of 236), respectively. It is noteworthy that group C rotavirus infection was apparently confined only within the period of 5 months (December 2002 through April 2003). This pattern of infection implied that the outbreak of group C rotavirus in these patients, which was the first outbreak of gastroenteritis attributed to group C rotavirus in Maizuru city. Moreover, about half (12 of 24) of group C rotavirus infected cases were confined to infants and young children less than 3 years old. Another interesting feature of the study was the demonstration of the mixed infections with group C rotavirus and group A rotavirus, as well as group C rotavirus and norovirus GII in 20.8% (5 of 24) and 8.3% (2 of 24), respectively. This is the first report of gastroenteritis associated with the mixed infections with group C rotavirus and other viral enteropathogens such as norovirus. The results indicate that group C rotavirus could infect not only older children and adults but also infants and young children under 3 years old.     

Epidemiology of rotavirus infection in Thailand

Rotavirus is a major cause of acute severe diarrhea in children worldwide and an important cause of death among young children in developing countries. Group A rotaviruses are antigenically complex and multiple serotypes infect humans. Reassortant rotavirus vaccines are now available which offer protection against severe illness caused by rotavirus serotypes G1-4. Before vaccines are introduced into target populations, it is necessary to establish the baseline data of the epidemiology of rotavirus infection in those countries. The purpose of the present study is to provide information related to the epidemiology of rotavirus infection in Thailand. All rotavirus studies performed in Thailand were found through Medline and Thai Index Medicus searches. A total of 26 of the most relevant studies published in international and national journals are reviewed. Most studies reported that the prevalence of rotavirus infection in Thailand was 27-34%, although a few studies have reported a prevalence above this range. The peak seasonal distribution of rotavirus infection among children hospitalized with diarrhea in Thailand was seen in the dry cool seasons: October to February. The prevalence of rotavirus infection was most frequently found in children aged 6-11 months up to 2 years. G1 was the most prevalent serotype in Thailand, followed by G2, G4 and G3, respectively. At least three G serotypes, mostly G1, G2 and G4, are seen to coexist in Thailand each epidemic year and in some studies all four G-serotypes were reported in the same epidemics. In a 1996-1997 study, G9 was the third prevailing serotype after G1 and G2, respectively. These results indicate that rotavirus epidemics occur in Thailand every year and children are the most affected population. In Thailand, although G1-G4 have been reported, G1 is the most prevalent serotype in each epidemic and G9 is becoming increasingly common.     

Evolutionary consequences of G9 rotaviruses circulating in Thailand

Infection with group A rotaviruses is the main cause of acute gastroenteritis in infants and young children worldwide. Rotavirus G9 is recognized as the fifth most predominant G genotype that spreads throughout the world. In this study, we describe the changing distribution of rotavirus G9 genotype in Chiang Mai, Thailand, from 1989 to 2005. Molecular genetic evolutionary analysis of the G9 rotavirus VP7 gene was performed. The G9 rotavirus in Thailand was first detected in Chiang Mai in 1989 with a low prevalence of 1.98%, but in 2000 and 2001 it had become the most predominant genotype, reaching prevalence of 75% and 92.2%, respectively. Then, the prevalence of G9 reached a peak of 100% in 2002 and decreased abruptly over the next 3 years, i.e. 16.7% in 2003, 32.1% in 2004, and 4.7% in 2005. Our phylogenetic analysis demonstrates that all the G9 rotaviruses circulating in Thailand belonged to lineage III, and clustered closely together based on the year of virus isolation. One amino acid change from Thr to Ile was observed in antigenic region C at position 208 between the G9 strains isolated in 1989 and the strains of 1997–2005. These findings provide the overall picture and genomic data of G9 rotaviruses circulating in Chiang Mai, Thailand.     

Toxicity of copper in butterfish (Poronotus triacanthus): tissues accumulation and ultrastructural changes

The present study investigated the accumulation of copper in various tissues and ultrastructural alterations in butterfish, Poronotus triacanthus. In acute toxicity test, butterfish were exposed to 250 microg/L copper for 24 h. In subacute toxicity test, fish were exposed to 25 microg/L copper for 7 days and then returned to normal water for 48 h. The levels of copper accumulation in the tissues were determined by using an atomic absorption spectrometer. After the 7 day exposure, the highest level of copper was found in the liver, followed by kidney, gills, and muscle tissues (3.64, 0.62, 0.59, and 0.34 microg/L, respectively). The recovery group has shown some reduction in copper level in these tissues when compared with those of the 7 day exposure group (3.09, 0.34, 0.30, and 0.27 microg/L, respectively). In gills, the major changes such as filament cell proliferation, increase in intercellular spaces, epithelial lifting, and thickening of the filament and lamellar epithelium were observed. In liver, the major changes such as swollen mitochondria, fragmented in rough endoplasmic reticulum, increases in number and size of lysosomes and lipid droplets. Infiltration of leukocytes, increasing hepatocyte size with pyknotic nuclei, and presence of vacuoles were also observed. In kidney, the changes included alterations of the first proximal tubules, as well as vacuolization of the cytoplasm, proliferation of lysosomes and mitochondria, dilation of endoplasmic reticulum, and finally, cell necrosis. The transmission electron microscopic analysis revealed that the 7 day exposure group had more severe effect in tissue alterations than the 24 h exposure group. Tissue regeneration was also observed in the 48 h recovery group.     

Identification of virulence-associated antigens and plasmids in Rhodococcus equi from patients with acquired immune deficiency syndrome and prevalence of virulent R. equi in soil collected from domestic animal farms in Chiang Mai,Thailand

The prevalence of virulent Rhodococcus equi in soil collected from 17 domestic animal farms (from 12 cattle, 1 pig, and 4 horse farms) and in 6 clinical specimens from patients with acquired immune deficiency syndrome (AIDS) in Chiang Mai, Thailand, was investigated. The isolates were tested for the presence of 15-17-kDa antigens (VapA) and a 20-kDa antigen (VapB) by immunoblotting and for the presence of virulence plasmid DNA. Rhodococcus equi was isolated from most soil samples (68 of 80) obtained from the 17 farms, with 2.0 x 10(2) to 6.0 x 10(5) colony-forming units per gram of soil. We detected VapA in none of the 537 isolates from the soil samples. In one isolate from a pig farm, both VapB and virulence plasmid DNA were detected. Of the 6 clinical isolates from patients with AIDS, however, 4 isolates contained both VapB and virulence plasmid DNA. The remaining 2 isolates were avirulent.     

普芦卡必利治疗慢性便秘的中国多中心随机、双盲、安慰剂对照临床研究

目的 评价普芦卡必利(2 mg,每日1次)对中国慢性便秘患者的疗效及安全性.方法 采用多中心、随机、双盲、安慰剂对照方法进行Ⅲ期临床研究,慢性便秘患者连续12周每日口服1次普芦卡必利(2 mg)或安慰剂.主要疗效指标为12周治疗期间平均每周完全自发排便(SCBM)≥3次的受试者比例.关键次要疗效指标为治疗前4周内平均每周完全自发排便(SCBM)≥3次的受试者比例.其他次要疗效指标包括每周平均SCBM次数、首次服药后出现第1次SCBM所需的时间、平均每周使用比沙可啶成灌肠剂的天数,并通过比较治疗前后PAC-SYM评分及PAC-QOL评分的变化评价患者的症状及生活质量改善情况.观察不良反应、实验室检查及心血管事件等安全性指标.结果 共筛选受试者446例,其中313例患者接受治疗,295例患者完成研究.治疗12周时,普芦卡必利组平均每周SCBM≥3次者的比例为39.4％,明显高于安慰剂组(12.7％,x2=29.50,P＜0.01).治疗4周时,普芦卡必利组平均每周SCBM≥3次者的比例为40.0％,明显高于安慰剂组(13.3％,x2=28.58,P＜0.01).患者总体症状及生活质量改善方面,普芦卡必利组优于安慰剂组.治疗期间常见的不良反应为腹泻、恶心、腹痛及头痛,基本为轻至中度,持续数天后即缓解.结论 普芦卡必利能显著且持续改善肠道功能,有效改善慢性便秘患者的相关症状,用以治疗中国慢性便秘患者安全、有效.     

Combined Ultrapulse CO2 Laser and Q-Switched Alexandrite Laser Compared with Q-Switched Alexandrite Laser Alone for Refractory Melasma: Split-Face Design

BACKGROUND. : Melasma is common and can cause major psychological impact. To date, the mainstay of treatment, including various hypopigmenting agents and chemical peels, is ineffective and can cause adverse effects. Laser is a new approach and is yet to be explored for its efficacy and safety. OBJECTIVE. : To compare combined Ultrapulse CO2 laser and Q-switched alexandrite laser (QSAL) with QSAL alone in the treatment of refractory melasma. METHODS. : Six Thai females were treated with combined Ultrapulse CO2 laser and QSAL on one side of the face and QSAL alone on the other side. The outcome was evaluated periodically for up to 6 months using the modified Melasma Area and Severity Index score and the modified Melasma Area and Melanin Index score. RESULTS. : The side with combination treatment had a statistically significant reduction of both scores. On the QSAL side, the score reduction was not significant. Two cases developed severe postinflammatory hyperpigmentation and were effectively treated with bleaching agents. Transient hypopigmentation and contact dermatitis were observed with the combination treatment side. CONCLUSIONS. : Combined Ultrapulse CO2 laser and QSAL showed a better result than QSAL alone but was associated with more frequent adverse effects. Long-term follow-up and a larger number of cases are required to determine its efficacy and safety for refractory melasma.     

Photocatalytic inactivation of diarrheal viruses by visible-light-catalytic titanium dioxide

Titanium dioxide (TiO2) that had been irradiated with visible light (VL) was demonstrated to inactivate rotavirus, astrovirus, and feline calicivirus (FCV). The virus titers were dramatically reduced after exposure for 24 hrs to the VL-catalytic TiO2. The addition of bovine serum albumin could protect the virus against inactivation by VL-catalytic TiO2 in a dose-dependent manner. This finding implied that the VL-catalytic TiO2 products might somehow interact initially with the viral proteins in the process of virus inactivation. Moreover, we showed partial degradation of the rotaviral dsRNA genome. This was more prominent when the virus was exposed to the VL-catalytic TiO2 treatment for at least 2 days. An attempt was made to elucidate the mechanism underlying the inactivation of the viruses. It was found that upon activation of TiO2 with VL by using a white fluorescent lamp, the reactive oxygen species such as superoxide anions (O2-) and hydroxyl radicals (*OH) were generated in a significant amount after stimulation for 8, 16, and 24 hrs. We therefore assume that virus inactivation by VL-catalytic TiO2 might occur through the generation of O2- and *OH followed by damage to the viral protein and genome. This is the first report, to the best of our knowledge, demonstrating the inactivation of rotavirus, astrovirus and FCV by the presence of TiO2 film under VL as well as describing its mechanism.     

Circulating of human bocavirus 1, 2, 3, and 4 in pediatric patients with acute gastroenteritis in Thailand

Human bocavirus (HBoV) is a newly identified human parvovirus that associated with respiratory and gastrointestinal diseases. Epidemiological surveillance of HBoV was conducted on fecal specimens collected from hospitalized children with diarrhea in Chiang Mai, Thailand in 2011. Among a total of 222 fecal specimens tested, 17 (7.7%) were positive for HBoV by PCR. Of the 17 HBoV positive samples, double- or triple-infections together with other enteric viruses were found in 10 (58.8%) pediatric patients, while monoinfection with HBoV alone was detected in seven (41.2%) cases. Mixed infection among HBoV with norovirus GII was frequently observed in this population. The partial VP1 nucleotide sequences of all 17 HBoV strains demonstrated that all four species of HBoV were found in the specimens tested. Eleven strains were HBoV1. Other three strains showed the sequence identity with HBoV2, which were most closely related to the HBoV2A. In addition, other two HBoV strains showed the highest level of nucleotide sequence identity with the HBoV3. It was surprisingly to observe that one Thai HBoV strain showed a unique characteristic similar to the HBoV4, a rare species of HBoV found in acute gastroenteritis patients. In summary, this study presents the genetic background information of HBoV circulated in acute gastroenteritis children in Chiang Mai, Thailand and it was clearly demonstrated that HBoVs circulated in this area were genetically diverse as all four species of HBoVs (HBoV1-4) were detected in the fecal specimens collected from pediatric patients admitted to the hospitals in this area.