Detection of Salmonella typhi protein antigen in serum and urine: a value for diagnosis of typhoid fever in an endemic area

Using haemoculture as the gold standard, a double antibody sandwich ELISA for the detection of Salmonella typhi Barber protein antigen (BP) was compared with the Widal test. Specimens used were serum and urine obtained from normal healthy individuals and from patients with typhoid fever, paratyphoid fever, pyrexia caused by other bacteria and pyrexia with negative haemoculture. The ELISA for antigenuria gave a significantly higher sensitivity, specificity, accuracy and positive predictive value than the Widal test (p less than 0.05). The ELISA for antigenaemia gave a significantly higher sensitivity and positive predictive value only. All other values were not significantly different. The timing of specimen collection was critical for sensitivity in the ELISA for antigenaemia and antigenuria, and the best results could be obtained by carrying out both assays simultaneously. The clearance of BP from serum into urine occurred around 16 days after the onset of fever in one patient. In two patients, BP could be detected in sera up to 3 weeks after the onset of fever. In two patients, serum BP could still be detected although haemoculture was negative.     

Prevalence and genotyping of Cryptosporidium SPP from dairy cow fecal samples in western Thailand

The aims of this study were to determine the prevalence of Cryptosporidium spp in dairy cows in central Thailand and to investigate the genotype of Cryptosporidium spp in this population. A total of 200 fecal samples from dairy cows were collected and examined by the acid-fast staining technique and polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The prevalence of Cryptosporidium infection in dairy cows was 7% (95% CI 3.5-10.5) by acid-fast staining, and 15.5% (95% CI 10.5-20.5) by PCR-RFLP. This is the first report of genetic identification of the C. parvum bovine genotype in dairy cows in Thailand. PCR-RFLP analysis showed all positive samples were C. parvum (bovine genotype). C. andersoni was not found in this study. The only significant risk factor for Cryptosporidium infection in dairy cows was age. Calves less than 2 months old were more frequently infected by Cryptosporidium than others (OR 13.82, 95% CI 3.67-51.97, p = 0.001). Cattle may be a potential source of human cryptosporidiosis.     

Shiga toxin- and enterotoxin-producing Escherichia coli isolated from subjects with bloody and nonbloody diarrhea in Bangkok,Thailand

A total of 314 stool samples collected from 92 subjects with bloody diarrhea, 119 subjects with non-bloody diarrhea and 103 normal subjects in Bangkok, Thailand, were investigated for the presence of Shiga toxin-producing Escherichia coli (STEC) and enterotoxin-producing E. coli (ETEC) by multiplex PCR assay. Virulence genes and cytotoxic effect to Vero cells of STEC were also determined. STEC (5 isolates) and ETEC (18 isolates) were detected in 3 and 14 subjects, respectively. Among subjects containing ETEC, only one person belonged to normal control group. The detected STEC included two isolates (serotypes O26:H(-) and O111:H(-)) of Shiga toxin type 1 (Stx1-only) STEC from a child with non-bloody diarrhea, two isolates (Stx1-Stx2 STEC and Stx1-only STEC) from an adult with bloody diarrhea, and one isolate of Stx1-Stx2v STEC (O157:H7) from normal child. Only Stx1-Stx2 STEC isolate was found to exhibit toxicity to Vero cells and carry hlyA gene. The intimin encoding gene locus eaeA was not detected in any isolate. These results indicate that most of STEC isolates in Thailand were low virulent.     

Chronic diarrhoea: a prospective study in Thai patients at Chulalongkorn University Hospital, Bangkok

Fifty-five Thai patients with chronic diarrhoea were prospectively studied to find out the underlying causes. The aetiology was identified in 38.2%, uncertain in 29.1%, and unknown in 32.7% of the patients. In the group with a definitive aetiologic diagnosis, parasitic and infective causes were commoner than non-infective causes. Amoebiasis and giardiasis were more frequent than expected, such that empirical therapeutic trial with an antiprotozoal may be justified if initial routine investigations fail to uncover the cause of the diarrhoea. No significant clinical features were noted between the infective and the non-infective groups. Overall, repeated stool microscopy using the concentration technique was the most useful single investigation in approaching the chronic diarrhoea problem.     

Specific primers for PCR amplification of the ITS1 (ribosomal DNA) of Trypanosoma lewisi

Trypanosoma lewisi is a mild or non-pathogenic parasite of the sub-genus Herpetosoma transmitted by fleas to rats. In a previous study we described pan-trypanosome specific primers TRYP1 which amplify the ITS1 of ribosomal DNA by hybridizing in highly conserved regions of 18S and 5.8S genes. These primers proved to be useful for detecting T. lewisi DNA in laboratory rats, but a recent large scale survey in wild rodents demonstrated a lack of specificity. In the present study, we designed and evaluated mono-specific primers LEW1S and LEW1R, for the detection and identification of T. lewisi by a single-step PCR. These primers were designed inside the highly variable region of the ITS1 sequence of T. lewisi ribosomal DNA. The product size of 220 bp is specific to T. lewisi. The sensitivity limit was estimated between 0.055 and 0.55 pg of DNA per reaction, equivalent to 1–10 organisms per reaction. All the PCR products obtained from 6 different T. lewisi isolates were more than 98% similar with each other and similar to the sequences of T. lewisi already published in Genbank. All DNA of 7 T. lewisi stocks from China gave the specific 220 bp product. We showed that LEW1S and LEW1R primers enabled sensitive detection and identification of T. lewisi infection in laboratory and wild rats. This assay is recommended for monitoring T. lewisi infections in rat colonies or for studying infections in the wild fauna. An absence of cross reaction with human DNA means that these primers can be used to investigate atypical trypanosome infections in humans. Given the risk of T. lewisi infection in human, we believe that these primers will be beneficial for public health diagnosis and rodents investigation programmes.     

Cholestatic liver diseases: An era of emerging therapies

Recently the field of cholestasis has expanded enormously reflecting an improved understanding of the molecular mechanisms underlying bile secretion and its perturbation in chronic cholestatic disease. Novel anti-cholestatic therapeutic options have been developed for patients not favorably responding to ursodeoxycholic acid (UDCA), the current standard treatment for cholestatic liver disease. Important novel treatment targets now also include nuclear receptors involved in bile acid (BA) homoeostasis like farnesoid X receptor and G protein-coupled receptors e.g., the G-protein-coupled BA receptor “transmembrane G coupled receptor 5”. Fibroblast growth factor-19 and enterohepatic BA transporters also deserve attention as additional drug targets as does the potential treatment agent norUDCA. In this review, we discuss recent and future promising therapeutic agents and their potential molecular mechanisms in cholestatic liver disorders.     

Asia Pacific Consensus Statements on Crohn's disease. Part 1: Definition,diagnosis, and epidemiology

Inflammatory bowel disease (IBD) was previously thought to be rare in Asia, but emerging data indicate rising incidence and prevalence of IBD in the region. The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology with the goal of developing best management practices, coordinating research, and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis with specific relevance to the Asia‐Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis, and management of Crohn's disease. The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia‐Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses, and treatment availability. It does not intend to be all comprehensive and future revisions are likely to be required in this ever‐changing field.     

Do gallstones found before sleeve gastrectomy behave the same as those formed after surgery due to weight loss?

Background

Gallstone formation is prevalent in the bariatric population and after weight loss. We believe that gallstones found preoperatively behave differently and may not cause significant complications as those developing after weight loss. Thus, prophylactic cholecystectomy before or during sleeve gastrectomy (SG) may not be necessary.

Methods

Patients undergoing SG from January 2011 to May 2012 were evaluated for the presence of gallstones and development of symptoms or need for cholecystectomy postoperatively.

Results

Group 1 (n = 18) had gallstones preoperatively. Group 2 (n = 29) developed gallstones after weight loss. Both groups' demographics were similar. Symptomatic gallstones occurred in 1 patient (5.6%) in group 1 and in 9 patients (31.0%) in group 2 (P = .19). Percent excess body mass index loss (%EBL) was 58 ± 24% vs 70 ± 22% (P = .11) with a mean follow-up of 8.9 ± 6.2 and 14.7 ± 3.9 months for group 1 and group 2, respectively (P = .005).

Conclusions

Asymptomatic gallstones found before SG tend to have less risk of becoming symptomatic than those formed after weight loss. There was no statistical significant difference because of small sample. Prophylactic cholecystectomy, however, may not be warranted in these patients.