Comparison of the performance of serological kits for Helicobacter pylori infection with European and Asian study populations.

Most commercial kits for the detection of Helicobacter pylori were developed and validated with Western populations, and some have been found to perform less well with Asian populations. This study compared the performances of three serological kits with Swedish and Vietnamese peptic ulcer patients and asymptomatic individuals. The Pyloriset EIA-GIII and HM-CAP ELISA kits indicated that Asian populations had lower antibody titres to H. pylori than European populations. Despite the difference, the Pyloriset EIA-GIII kit performed well with Vietnamese peptic ulcer patients and population controls. The HM-CAP ELISA kit had a significantly lower performance with Asian populations that could not be improved by adjustments to the cut-off level. The Helicoblot 2.1 immunoblot kit performed equally well with Vietnamese and Swedish populations, although the response rate to the 35-kDa band was significantly lower with Vietnamese individuals.

Long-term follow-up of Helicobacter pylori eradication therapy in Vietnam: reinfection and clinical outcome.

AIM: To assess the long-term Helicobacter pylori reinfection rates, as well as the clinical outcome in peptic ulcer disease patients in Vietnam. METHOD: At a 1-year evaluation of H. pylori eradication treatment in 226 peptic ulcer patients, long-term H. pylori status was assessed with serology and/or culture, peptic ulcer status by gastroscopy, and DNA-fingerprinting performed with random amplified polymorphic DNA and restriction fragment polymorphism. RESULT: Follow-up was performed a mean 11 months after the post-treatment evaluation on day 30 after beginning of treatment. The overall reinfection rate was 23.5%, with 58.8% of the strains being identical to the pre-treatment isolates and 41.2% being different. Peptic ulcer was found in 22.9% of the reinfected patients and in 6.3% of the non-reinfected. At the long-term follow-up of successful eradication cases, 89.8% of the patients were free of peptic ulcer disease. The corresponding result was 58.7% in patients in whom H. pylori eradication failed. CONCLUSION: Following successful H. pylori eradication, reinfection with H. pylori in patients in Vietnam was found to be higher than in industrialized countries but the long-term recurrence of peptic ulcer disease was still low. Helicobacter pylori eradication treatment is therefore of value also in developing countries as the rate of peptic ulcer disease was low at the 1-year follow-up.

Helicobacter pylori eradication and peptic ulcer healing: the impact of deleting the proton pump inhibitor and using a once-daily treatment.

AIM: To compare cheaper and simpler once-daily regimens, with and without a proton pump inhibitor, with standard, twice-daily, triple therapy. METHODS: A randomized, placebo-controlled, treatment trial in Vietnam allocated 296 Helicobacter pylori-infected patients with peptic ulcer of >or= 5 mm to one of three regimens: (i) twice-daily: lansoprazole 30 mg, clarithromycin 250 mg and tinidazole 500 mg; (ii) once-daily: lansoprazole 60 mg, clarithromycin 500 mg and tinidazole 1000 mg; (iii) once-daily: placebo, clarithromycin 500 mg and tinidazole 1000 mg. H. pylori status was assessed by culture and immunoblot, ulcer healing by endoscopy and side-effects by structured questionnaires. RESULTS: Per protocol eradication (N = 256) was higher with standard therapy (87%) than with once-daily therapy (72%), and both were better than once-daily therapy without proton pump inhibitor (39%). Per protocol ulcer healing after standard therapy (83%) was not significantly better than that after once-daily therapy (73%), but better than that after therapy without proton pump inhibitor (65%). Side-effects were reported at similar rates in all groups. CONCLUSIONS: Proton pump inhibitor was needed for optimal eradication and ulcer healing. Twice-daily administration showed improved success rates when compared with once-daily therapies. Peptic ulcer healing was achieved even in patients treated with antibiotics only, confirming the central role of H. pylori in the pathophysiology of peptic ulcer disease.

Incidence and predictors of surgical-site infections in Vietnam.

OBJECTIVE: To determine the incidence of, and risk factors for, surgical-site infections (SSIs). DESIGN: Prospective observational study of all patients undergoing surgery during a 3-month period. SETTING: Two urban hospitals in Hanoi, Vietnam. PATIENTS: All 697 patients admitted for emergent and elective surgery. METHODS: Data were collected on all patients undergoing surgery during a 3-month period at each hospital. We stratified the data by type of surgery, wound class, and Study on the Efficacy of Nosocomial Infection Control (SENIC) risk index. The analysis was done with the data sets from each hospital separately and with the combined data. The risk factors for SSI were identified using a logistic-regression model. RESULTS: During the period of observation, 10.9% of 697 patients had SSI. The SSI rate was 8.3% for clean wounds, 8.6% for clean-contaminated, 12.2% for contaminated, and 43.9% for dirty wounds. The lowest rate of SSI (2.4%) was found in obstetric-gynecologic procedures and the highest rate (33.3%) in cardiothoracic operations. Using the SENIC risk index, the incidence of SSI in low-risk patients was 5.1%; for medium-risk patients, 13.5%, and high-risk patients, 24.2%. In a logistic-regression model, abdominal surgery (odds ratio [OR], 4.46; P<.01) and wound class IV (OR, 5.67; P<.01) were significant predictors of SSI. All patients were treated with prolonged courses of perioperative antibiotics. Overall infection control practices were poor as a result of deficient facilities, limited surgical instruments, and a lack of proper supplies for wound care and personal hygiene. CONCLUSIONS: There was a higher incidence of SSI in low-risk patients in Vietnam compared with developed countries. Excessive reliance on antimicrobial therapy as a means to limit SSI places patients at higher risk of adverse effects from treatment and also may contribute to worsening problems with antimicrobial resistance. Establishment of an infection control program with guidelines for antimicrobial use should improve the use of prophylactic antibiotics and attention to proper surgical and wound-care techniques. These interventions also should reduce the incidence of SSI and its associated morbidity and costs.

The humoral antibody response to Shigella dysenteriae type 1 infection, as determined by ELISA.

An enzyme-linked immunosorbent assay (ELISA) for determining the class-specific humoral antibody response to the lipopolysaccharide antigen from Shigella dysenteriae serotype 1 bacteria has been tested. Two or more serum samples from each of 60 persons infected with this organism during a dysentery outbreak in a boarding school for young men near Haiphong, Viet Nam, and single serum samples from 39 healthy Vietnamese and from 20 healthy Swedes were included in the study. Comparison of the titres in the sera from the patients and the Vietnamese controls showed that the patients had significantly elevated IgA titres in sera collected 10, 30 and 45 days after onset of infection, and significantly elevated IgG titres in sera collected 30, 45 and 180 days after the onset. The titres in the patients' sera, compared with those in the Swedish controls, were significantly elevated for IgA and IgM as well as IgG in the samples collected after 10, 30, 45 and 180 days. The use of rabbit antisera, specific for enteropathogenic bacteria, and absorption experiments with human sera indicated that the S. dysenteriae type 1 lipopolysaccharide antigen is specific with respect to the O-antigenic polysaccharide chain.