Surveillance and risk factors of norovirus gastroenteritis among children in a southern city of China in the fall-winter seasons of 2003-2006.

AIM: Noroviruses (NoVs) are an important cause of acute gastroenteritis but knowledge on the disease burden and epidemiology in children in the developing countries remains limited. In this study, we performed a surveillance of NoV gastroenteritis in children of China to address some of the questions. METHODS: Faecal specimens from children (<5 years of age) at outpatient clinics of the Nan Fang Hospital in Guangzhou, China during the fall-winter seasons in 2003-2006 were tested for rotaviruses (RVs) and NoVs. A questionnaire on clinical records and hygiene habits was collected from each patient. RESULTS: Among 957 stool specimens tested, 488 (51%) specimens were positive for RVs. NoVs were detected in 112 (24%) of the 469 RV negative specimens. The Genogroup II (GII), particularly GII-4, viruses were predominant. No significant difference of clinical symptoms, hospitalisation and patient care expenses were found between children infected with NoVs and RVs. Consumption of uncooked food is a risk for NoV infection. Contact with diarrhoea patients is a suspected risk factor. Cutting nails frequently is a protective factor against NoV infection. CONCLUSIONS: NoVs are an important cause of acute gastroenteritis in children which need special attention of patient care at the clinics in addition to RVs. The awareness of those risk factors may help future disease control and prevention.

[An epidemiological investigation of bats carrying SARS-CoV in Guangzhou and its vicinity].

OBJECTIVE: To detect serve acute respiratory syndrome-associated coronavirus (SARS-CoV) and SARS-like-CoV in fruit bats captured in Guangzhou and its vicinity. METHODS: Totally 927 bats of 9 species (Cynopterus sphinx, Rousettus leschenaulti, Miniopterus schreibersi, Hipposideros pratti, Rhinolophusasinicus, Scotophilusakuhlii, Hipposideros Pomona, Rhinolophus affinis, and Rhinolophus pusillus) captured in Guangzhou and its vicinity from September 2004 to November 2005 were available for this investigation, from which 3,043 samples (813 throat swasb, 524 sera, 853 lung tissues and 853 colorectal tissue specimens) were obtained. SARS-Cov and SARS-like-CoV were detected in these specimens using diagnostic kit for novel coronavirus N protein (ELISA), SARS-CoV Virus RNA detection kit, fluorescence PCR, Genchip, RT-PCR and cell isolation culture methods. RESULTS AND CONCLUSION: No SARS-CoV and SARS-like-CoV were detected in the 3043 samples, indicating the current absence of SARS-CoV and SARS-like-CoV in the bats captured in Guangzhou and its vicinity.

[Molecular epidemiological study of human calicivirus infection in diarrhea children in autumn and winter at a hospital in Guangzhou].

OBJECTIVE: To investigate the epidemiological features of human calicivirus( HuCV) infection in children with diarrhea in a hospital in Guangzhou. METHODS: Stool specimens were collected from children with viral diarrhea diagnosed between October, 2003 and January, 2004 and between October, 2004 and January, 2005. HuCV was detected by means of RT-PCR and sequence analysis of the PCR products. RESULTS: Eighty specimens positive for Norwalk-like viruses (NLVs) were identified from 648 stool specimens, with a positivity rate of 12.35%, and sapporo-like viruses (SLVs) were identified in 2 specimens (0.31%). The monthly NLV positivity rate was 11.74% (Oct.), 14.16% (Nov.), 9. 09% (Dec.) and 13.95% (Jan.), respectively, showing no significant variation in these months. NLVs mainly infected children below 2 years old. Twenty-two strains of NLVs were sequenced and analyzed, and 21 of them were identified as GII and the genotype of 1 strain could not be determined. The prevalent viral population were GII-3 and GII-4 in 2003 and was GII-4 in 2004, and both of the SLVs belong to GI-1. CONCLUSION: NLVs is one of the important pathogens causing sporadic acute gastroenteritis in children admitted in the hospital in Guangzhou, and the prevalent strains are GII-3 and GII-4 , but different prevalent strains are possible in different periods.

[Molecular epidemiology of diarrhea among children with Norwalk-like virus in a hospital of Guangzhou in autumn and winter].

OBJECTIVE: To explore the epidemiological characteristics of Norwalk-like virus (NLVs) infection in children with diarrhea and to study the genotype and predominant cluster at a hospital in Guangzhou city. METHODS: Fecal specimens from 358 children with acute gastroenteritis from October 2003 to January 2004 and information about the cases were collected. NLVs was detected from the specimens by reverse transcription-polymerase chain reaction (RT-PCR) and the PCR products were purified and sequenced. RESULTS: Forty-two positive specimens were detected from the 358 fecal specimen with a positive rate of 11.73% (42/358). Of these, 40 specimens were obtained from infants younger than 3 years of age. The youngest infant infected with NLVs in this study was only 25 days. The positive rate in November (17.27%) was the highest. Eleven positive PCR products were selected and sequenced. Nucleotide sequence analysis revealed that 11 strains all belong to genogroup II (G II), and of these, 5 strains belonged to G II-3 cluster, with another 5 strains belonged to G II-4 cluster. However, one strain with its cluster could not be determined. CONCLUSION: NLVs served as one of the important pathogens causing sporadic acute gastroenteritis among children at a hospital in Guangzhou. The predominant strains were identified as G II-3 and G II-4 cluster.

[Detection and sequence analysis of Sapporo-like virus in Guangzhou].

OBJECTIVE: To verify the presence of Sapporo-like virus (SLV) in children with diarrhea in Guangzhou. METHODS: Stool specimens were collected from children with diarrhea treated in the Department of Pediatrics of Nanfang Hospital in autumn and winter, 2003, and semi-nested reverse transcriptase-polymerase chain reaction (RT-PCR) was employed for SLV detection, the positive product of which was sequenced and analyzed in comparison with the SLV sequences documented in GenBank. RESULTS: Only one positive specimen (CH03354) was found out of the 169 stool specimens collected. Sequence analysis of the capsid gene of this strain showed that it belonged to SLV GI-1 cluster. CONCLUSION: SLV exists in Guangzhou and different regions of China may have different genotypes of this virus.

Differential expression of the enzyme that esterifies retinol, lecithin:retinol acyltransferase, in subtypes of human renal cancer and normal kidney.

PURPOSE: Retinoids, a group of compounds, including vitamin A (retinol), and related metabolites, have been shown to regulate the growth and differentiation of many types of cells. IFN-alpha and either 13-cis-retinoic acid or liposomal all-trans retinoic acid have been used in the treatment of patients with metastatic renal cell carcinoma. We knew that samples from renal cell carcinomas contained greatly reduced levels of retinol and retinyl esters relative to samples from normal human kidney. This prompted us to examine the levels of LRAT (lecithin:retinol acyltransferase) protein in various subtypes of human kidney cancers relative to normal human kidney by immunohistochemistry. EXPERIMENTAL DESIGN: We examined 31 partial or radical nephrectomy specimens diagnosed with kidney tumors between 1997 and 1998. Representative paraffin-embedded tissue blocks from each tumor, with each containing adjacent nonneoplastic renal parenchyma, were used for immunohistochemical analysis with affinity purified antibodies to human LRAT protein. RESULTS: LRAT protein was detected at high levels in the epithelial cells in the tubules and the lining of Bowman's capsule in the glomeruli of normal, nonneoplastic kidney sections. Among the 31 tumors, there were 13 cases of conventional (clear cell) renal cell carcinoma (RCC; including 2 multilocular cystic RCCs), 7 papillary RCC, 6 chromophobe RCC, 1 RCC, unclassified, and 4 renal oncocytoma. All tumors showed diffuse immunoreactivity for LRAT. In each case, the staining was uniform throughout the tumor, with only minimal variation in the staining intensity between different areas. All 4 renal oncocytomas, 2 of 6 chromophobe RCCs, 1 conventional (clear cell) carcinoma, 1 RCC, unclassified, and 2 conventional RCCs, which were of the multilocular cystic-type stained strongly (3+) for LRAT. In contrast, the remaining conventional RCCs and the papillary RCC samples stained much less intensely for LRAT. Of the 10 tumors that stained 3+ for LRAT in the study, 9 were either benign tumors or tumors with low malignant potential. CONCLUSIONS: These data show that LRAT expression is higher in renal tumors with an indolent biological behavior. Additional studies will ascertain if LRAT possesses any prognostic or therapeutic role in renal cancer.