Examining DNA fingerprinting as an epidemiology tool in the tuberculosis program in the Northwest Territories, Canada.

BACKGROUND: Tuberculosis (TB) is an important public health problem in the Northwest Territories (NWT), particularly among Canadian Aboriginal people. OBJECTIVE: To analyse the transmission patterns of tuberculosis among the population living in the NWT, a territorial jurisdiction located within Northern Canada. METHODS: This population-based retrospective study examined the DNA fingerprints of all laboratory confirmed cases of TB in the NWT, Canada, between 1990 and 2009. An isolate of each lab-confirmed case had genotyping done using IS6110 Restriction Fragment Length Polymorphism. DNA patterns were assigned to each DNA fingerprint, and indistinguishable fingerprints patterns were assigned a cluster. Social network analysis (SNA) was used to examine direct linkages among cases determined through conventional contact tracing (CCT), their DNA fingerprint and home community. RESULTS: Of the 225 lab-confirmed cases identified, the study was limited to 195 subjects due to DNA fingerprinting data availability. The mean age of the cases was 43.8 years (±22.6) and 120 (61.5%) males. The Dene (First Nations) encompassed 120 of the cases (87.7%), 8 cases (4.1%) were Inuit, 2 cases (1.0%) were Metis, 7 cases (3.6%) were Immigrants and 1 case had unknown ethnicity. One hundred and eighty six (95.4%) subjects were clustered, resulting in 8 clusters. Trend analysis showed significant relationships between with risk factors for unemployment (p=0.020), geographic location (p≤0.001) and homelessness (p≤0.001). Other significant risk factors included excessive alcohol consumption, prior infection with Mycobacterium tuberculosis and prior contact with a case of TB. CONCLUSIONS: This study demonstrates how DNA fingerprinting and SNA can be additional epidemiological tools, along with CCT method, to determine transmission patterns of TB.

Epidemiology of Haemophilus influenzae serotype a, North American Arctic, 2000-2005.

Before the introduction of Haemophilus influenzae type b (Hib) conjugate vaccines, rates of invasive H. influenzae disease among indigenous people of the North American Arctic were among the highest in the world. Routine vaccination reduced rates to low levels; however, serotype replacement with non-type b strains may result in a reemergence of invasive disease in children. We reviewed population-based data on invasive H. influenzae in Alaska and northern Canada from 2000-2005; 138 cases were reported. Among 88 typeable isolates, 42 (48%) were H. influenzae type a (Hia); 35 (83%) occurred in indigenous peoples. Among Hia patients, median age was 1.1 years; 62% were male; 1 adult died. Common clinical manifestations included meningitis, pneumonia, and septic arthritis. Overall annual incidence was 0.9 cases per 100,000 population. Incidence among indigenous children <2 years of age in Alaska and northern Canada was 21 and 102, respectively. Serotype a is now the most common H. influenzae serotype in the North American Arctic; the highest rates are among indigenous children.

Enzyme content and acid stability of enteric-coated pancreatic enzyme products in vitro.

OBJECTIVES: Pancreatic enzymes are prescribed routinely for pancreatic insufficiency. In the current health care environment, drug substitution is commonly performed although there is no proof of therapeutic or bioequivalence for these products. The purpose of this in vitro, prospective study was to evaluate the enzyme contents and dissolution of various capsules of pancreatic enzyme using current United States Pharmacopoeia (USP) methodology. METHODS: Nine different pancreatic enzyme products were purchased on the market and supplied to Irvine Analytical Laboratories (IAL) (Irvine, CA). All test products were maintained in the laboratory environment, at room temperature, throughout the testing period by IAL. USP procedures for assay and dissolution testing of pancrelipase delayed-release capsules, as described in the latest USP supplement were observed during product testing, including determination of amylase, lipase, and protease activity. In addition, a point assay with measurement of lipase after dissolution in simulated gastric fluid pH of 1.0 for 1 hour and then dissolution in pH 6 phosphate buffer for 30 minutes performed in accordance with USP guidelines. RESULTS: Assay results of amylase, protease, and lipase from the 9 tested products are within USP specified limits. The percentage of label claim for these enzymes was higher than depicted in their label except for one drug batch. However, the percentage of lipase activity after dissolution varied with 2 of 3 batches of 1 drug not dissolving, and 1 batch of another drug, revealing only 8% lipase activity in the USP dissolution test. CONCLUSION: While assay of pancreatic enzymes reveal they were equal to their USP claims regarding their enzyme content, not all pancreatic enzyme replacements are equal in their release of lipase activity according to USP requirements. The findings maybe clinically seen with therapeutic failures of enzyme products. The FDA has recently decreed that all pancreatic enzyme products will require an approved NDA as differences in pharmaceutical quality have been identified in this product. Thus, it is considered that substitution of these products maybe questionable. Things are seldom what they seem- not all pancreatic enzyme replacements are equal. Further studies are warranted to investigate dissolution characteristics.