Ethnic epidemiological profiles and antiviral therapy among patients infected with hepatitis C virus genotype 4: a multicenter study from Belgium.

BACKGROUND: Hepatitis C virus genotype 4 (HCV-4) is the most prevalent genotype in Central Africa. AIM: To compare epidemiology, clinical characteristics and any differences in access to HCV therapy in two populations of HCV-4 patients residing in Belgium. METHODS: This multicenter study selected 473 HCV-4 patients from seven hospital databases and compared them according to ethnic origin, i.e., Black African (n=331) or not (n=142), for epidemiological, clinical, biological and histological characteristics. Interleukin 28B polymorphism (CC-genotype) was evaluated in a second cohort of 69 Black African and 30 non-Black African patients. RESULTS: Compared to other patients, the Black African patients were more likely to be female and were older, commonly overweight, frequently had abnormal glucose metabolism and arterial hypertension ; they were less likely to have dyslipidemia, a history of alcohol consumption or ALT elevation. The route of infection was more frequently unknown in Black African than in other patients. Black African patients had more HCV-4 subtypes, were less frequently of IL28B CC-genotype and had less severe liver fibrosis. The proportion of patients who received antiviral treatment was similar in the two groups. CONCLUSION: In this Belgian cohort, patients with HCV-4 infection were more frequently of Black African origin than of other origin. Infected Black African patients were more commonly -female, older at diagnosis, and had more co-morbidities than other patients; they also had less advanced liver fibrosis than infected non-Black African patients and fewer had a CC genotype.

New identification characteristics of methicillin-resistant Staphylococcus aureus on chromogenic culture media.

Methicillin-Resistant Staphylococcus aureus (MRSA) is one of the most common and important causes of nosocomial infections. Rapid detection of this pathogen is important for conducting good and swift infection control. This prospective study evaluates two chromogenic media for the detection of MRSA. New colony characteristics were noticed during this evaluation: (i) a yellow/golden colouration on a pipette after streaking the colonies of the chromogenic culture could eventually be used as a supplementary identification test to identify the MRSA strains, and (ii) some MRSA strains do not metabolise the chromogens and therefore are not coloured on chromogenic agars. However, they have a typical yellow/golden colony aspect usually observed amongst S. aureus.

Metabolic disorders associated with chronic hepatitis C: impact of genotype and ethnicity.

BACKGROUND & AIM: Patients with hepatitis C virus (HCV) infection, especially those with genotypes 1 and 4, have an increased risk of developing metabolic disorders. The aim of this study was to evaluate the associations among metabolic disorders, ethnicity and genotype in a large cohort of patients with chronic hepatitis C (CHC). PATIENTS AND METHODS: All consecutive patients with CHC who were seen in our hepato-gastroenterology unit between January 2002 and September 2008 were included. Demographical data and variables related to the metabolic syndrome were collected. Insulin resistance was assessed using the homeostasis model for the assessment of insulin resistance test (HOMA-IR) test. RESULTS: Among the 454 CHC patients, the prevalence of the metabolic syndrome was 12.4%. The HOMA-IR test was performed in 140 patients, and 35.0% had insulin resistance. There were more Black Africans among the patients with genotypes 1/4 than among those with genotypes 2/3 (32.0 vs 1.2%, P<0.0001). Insulin resistance was more common in patients with genotypes 1/4 than in those with genotypes 2/3 (17 vs 1.7%, P=0.0001 and 43.3 vs 16.3%, P=0.001, respectively). Genotypes 1/4 were more frequently present in patients with insulin resistance than in those without insulin resistance (85.7 vs 60.5%, P=0.001). By logistic regression, genotypes 1/4 [odds ratio (OR)=2.79; 95% confidence interval (CI): 1.09-7.12, P=0.032] and older age (OR=1.03; 95% CI: 1.004-1.06, P=0.024) were independently associated with the presence of insulin resistance. CONCLUSIONS: In CHC, insulin resistance is independently associated with the presence of genotypes 1/4. Ethnicity is not independently associated with metabolic disorders in patients with CHC.

A prospective evaluation of selection criteria for the use of Nucleic Acid Amplification Techniques to test for the presence of Mycobacterium tuberculosis in respiratory tract samples.

BACKGROUND: Although Mycobacterium tuberculosis (MTB) can be detected rapidly by means of Nucleic Acid Amplification Techniques (NAT), these NAT tests are expensive and therefore are not used in routine practice or as a screening tool. METHODS: Although it is generally accepted that clinical and radiological data are important markers for deciding whether to test for MTB using NAT, the optimal combination of markers has not been determined. A prospective study was performed to evaluate NAT using different combinations of clinical, laboratory and radiographic selection criteria. RESULTS: The sensitivity of NAT for detecting MTB in patients with smear negative for acid-fast bacilli was two times higher in patients with radiographic abnormalities and negative routine bacterial culture for respiratory pathogens than those with absence of radiographic abnormalities or positive routine bacterial culture (77.8% vs. 33.3%; p<0.001). Furthermore, a difference of almost 40% can be observed between the positive predictive values of both groups (87.5% vs. 50.0%; p<0.001). CONCLUSIONS: Using a combination of clinical, laboratory and radiographic criteria, it is possible to identify patients in whom the NAT for MTB has reasonable sensitivity and specificity. Using these selection criteria should reduce costs associated with the inappropriate use of NAT tests.

Development of a multiple internal control for clinical diagnostic real-time amplification assays.

A major pitfall in most published genomic amplification methods for the detection and identification of human pathogens is that they do not include an internal amplification control in order to achieve an acceptable level of confidence for the absence of false-negative results. By applying composite primer technology, a single multiple internal amplification control DNA molecule was constructed to detect and quantify the hepatitis B virus, human polyomavirus, Epstein-Barr virus, Toxoplasma gondii and cytomegalovirus using real-time PCR. The multiple internal amplification control contains all forward and reverse primer binding regions targeted in the five distinct duplex PCRs, but with a unique probe hybridization site. Multiple internal amplification control detection sensitivity, assessed by Probit analysis, was 58 copies per PCR, associated with an extremely wide dynamic range (8 log(10) units). Moreover, in testing 614 patient samples, PCR inhibition occurred at a frequency of 0-8.8%. Similar multiple internal amplification controls for quantitative PCR-based assays could be designed to accommodate any infectious profiles in a particular institution as they are easy to make and inexpensive.

Clinical and microbiological features of dientamoebiasis in patients suspected of suffering from a parasitic gastrointestinal illness: a comparison of Dientamoeba fragilis and Giardia lamblia infections.

OBJECTIVES: To describe the clinical and microbiological features of Dientamoeba fragilis and Giardia lamblia infected patients, and to analyze the genetic variation of D. fragilis strains. METHODS: For a period of two years, all stool samples collected from patients suspected of having a parasitic gastrointestinal infection were examined according to our specific triple feces test (TFT) protocol. A retrospective case-control study was performed on D. fragilis and G. lamblia infected patients. Furthermore, PCR and genotyping by restriction fragment length polymorphism (RFLP) were performed upon the former. RESULTS: D. fragilis (6.3%) and G. lamblia (7.1%) were the most common pathogenic protozoa isolated out of 448 patients studied. Symptoms most frequently encountered with D. fragilis and G. lamblia infection were abdominal pain (69.2% and 72.4%, respectively) and diarrhea (61.5% and 79.3%, respectively). However, patients with D. fragilis infections suffered significantly less frequently from nausea and/or vomiting, anorexia and weight loss. After treatment, all D. fragilis and G. lamblia infected patients presenting a negative TFT follow-up also reported a complete resolution of their symptoms. Only genotype 1 could be detected in D. fragilis infected patients. CONCLUSIONS: D. fragilis and G. lamblia were the most frequently encountered parasites in our study population. Improved diagnostic tests are essential tools to study the prevalence and pathogenesis of D. fragilis.