Transcription

1

2

3

4

5

6

7

8

9 Halton Region Health Department Vol 13, Issue 2 Summer 2006 To all Halton Physicians The following topics are included in this update: West Nile Virus Update Update on Mumps Hepatitis B Immunization for High Risk Babies Ordering TB Medications Men C Vaccine Eligibility Hepatitis C: A review for physicians Influenza Activity Avian Influenza Update Nasopharyngeal Swabs New Diagnostics for TB Notice: Seminar for Community Nurses This issue of the Vaccine & Communicable Disease Update includes a fact sheet for physicians about Lyme disease describing the epidemiology of the disease, as well as diagnosis, treatment, and prevention information. Lyme disease is reportable, including erythema migrans, even in the absence of laboratory evidence. Robert M. Nosal MD FRCPC Medical Officer of Health Halton Region It s time to order your influenza vaccine. Please fax your orders to the Vaccine Depot Service at by August 1 st. West Nile Virus Update In 2005, there were 5 human cases of West Nile virus in Halton Region; four in Burlington residents and one in an Oakville resident. There were no deaths attributed to the virus. This was the first year since 2002 that human cases were detected in Halton. The case definition for West Nile virus is unchanged from last year. During summer and early fall, West Nile virus infection should be one of the diagnostic considerations for patients presenting with symptoms of meningitis or encephalitis both of which are reportable conditions in addition to those presenting with paralysis, weakness, movement disorders or certain other neurologic conditions. Suspect cases presenting with West Nile Non- Neurological Syndrome should be reported to the Health Department immediately if the patient has donated or received blood or tissue products within the previous 8 weeks. Otherwise, reporting can be delayed in the absence of meningitis or encephalitis until there is laboratory support. Testing IgM ELISA for WNV, and HI for St. Louis encephalitis, Eastern Equine encephalitis, Western Equine encephalitis, Powassen and Dengue will be automatically done for all suspect cases of human viral meningitis/encephalitis. When requesting testing, order IgM ELISA for WNV, use the public health laboratory requisition form and request arbovirus testing (code V02). It is helpful for the laboratory if the physician includes key clinical details and travel history on the requisition. For a WNV physician information package, please visit the Ministry of Health and Long-Term Care website at: _mn.html. Click on Public Health then scroll down to, and click on, West Nile Virus.

10 Update on Mumps Health agencies across Canada have been monitoring a recent outbreak of mumps in the U.S., specifically in the mid-western states. During January 1, 2006 to June 3, 2006, 11 states reported 3,633 cases of mumps; the majority 53% (1,924) were reported from Iowa. Associated cases have been detected in Hamilton and Wellington-Dufferin-Guelph health unit areas. Although Halton Region Health Department has received several reports of suspected mumps cases, none of the reports have met the case definition for mumps. Clinically compatible signs and symptoms include fever and tender, self-limited swelling of the salivary glands lasting 2 or more days. Should a physician suspect mumps, laboratory testing should be undertaken as described below: Laboratory testing Confirmation of mumps infection can be made by virus isolation or by serologic testing. Specimens should be obtained early in the course of illness when the virus titre is highest. a) Serology: Serological diagnosis by both acute and convalescent titres (mumps-specific IgM and IgG) is recommended. The acute specimen should be obtained as soon as possible after the onset of parotitis. The convalescent specimen should be drawn 14 days or more after symptom onset to check for a significant rise in mumps-specific IgG antibodies between acute and convalescent sera. Seroconversion or a significant rise in IgG titre is indicative of recent infection. b) Virus isolation: A nasopharyngeal swab or aspirate, or a throat swab should be obtained within 8 days after the onset of parotitis, and/or approximately 50 ml of urine within 14 days after the onset of parotitis. Laboratory requisitions should be clearly marked suspect case of mumps and sent to the public health laboratory. Inclusion of information on recent vaccination and travel history would also be useful. Please report any suspect cases of mumps to the Health Department. Hepatitis B Immunization for High Risk Babies Source: Canadian Immunization Guide 6 th Edition Infants born to mothers who are infected with the hepatitis B virus should have received the first dose of hepatitis B vaccine as well as hepatitis B immune globulin shortly after birth (within 12 hours of birth). The second and third dose of the vaccine series should be given 1 and 6 months after the first. Testing of the infant for HBsAg and anti-hbs is recommended 1 month after completion of the vaccine series to monitor the success of immunoprophylaxis. If HBsAg is found, the child is likely to become a chronic carrier. If the infant is negative for both HBsAg and Anti-HBs (i.e., a non-responder), additional doses up to a second full course of vaccine should be given, with repeated serologic testing for antibody response. Ordering TB Medications Medications for the treatment of active and latent tuberculosis are publicly funded. Treatment for atypical tuberculosis is not. To order the publicly-funded medication, please FAX the prescription to Pharmex at (Toll-free at ). The medication will be delivered to the Health Department and, on receipt, the Health Department staff will make arrangements for the medications to reach the patient. MenC Vaccine Eligibility Since 2005, as a catch-up program, students in Grade 7, all high school students, and youth aged have been eligible for publicly-funded MenC vaccine. Individuals who were eligible in 2005 continue to be eligible, even if they are currently outside these age groups. Routine MenC immunization is scheduled for 12-month-olds. Many colleges and universities, both in Canada and the United States, require or strongly recommend this vaccine before admission to the school or residence. For further information about this and other publiclyfunded vaccines, please visit the Ministry of Health website at immun/prof_immunization.html. Hepatitis C The following is reproduced with permission of the author. Although many patients are unaware of their HCV infection status, primary care physicians are in a unique position to help identify, counsel, refer and monitor patients at risk of HCV infection and its associated infections and complications. Ongoing awareness by Vaccine & CD Update Vol 13; Issue 2; Summer 2006

11 patients and primary care physicians of factors that promote HCV transmission and disease progression may reduce the burden of disease and identify more patients who would benefit from effective therapy. If a patient has hepatitis C, look specifically for contraindications to antiviral therapy (Box 2) in the clinical evaluation and for signs of liver disease such as spider nevi and palmar erythema. Jaundice, hepatosplenomegaly, ascites, encephalopathy and gastroesophageal varices are signs of more advanced disease. Baseline laboratory test results should be obtained. The patient can then be referred to a specialist to assess management options. The complex decision whether to initiate antiviral therapy needs to be based on factors such as the patient's interest, barriers to adherence, clinical and laboratory findings, probability of disease progression without therapy, odds of treatment success, likelihood of adverse effects and absolute and relative contraindications to therapy. To view the entire article, visit Source: Wong T, Lee, SS. Hepatitis C: a review for primary care physicians. CMAJ, 2006; Vol 174, Issue 5 Influenza Activity Doses Distributed Over 172,900 doses of influenza vaccine have been distributed through the Health Department s Vaccine Depot Service. This reflects an increase of almost 6,000 doses over last year, with the largest increase being in physicians offices. Influenza Activity As of May 31, 2006, 131 cases of influenza had been confirmed in Halton Region. The pattern of influenza illness was considerably different this year. Later than previous seasons, influenza activity peaked in late March and continued well into May, with the last institutional influenza outbreak being reported on May 30, 2006 in a rest and retirement home setting. This pattern of illness was similar to that in other parts of Canada, particularly the rest of Ontario and Quebec. Strain Characterization and Vaccine Match Across Canada, the mix of influenza cases this season has been 60% A-type and 40% B-type. To date, 100% of the influenza A strains characterized by the National Microbiology Laboratory (NML) have matched those included in the Canadian vaccine. However, 99% of the influenza B strains characterized belonged to the B/Victoria/02/1987 lineage (B/Malaysia/2506/2004- like), and were not covered by this year s vaccine. Vaccine for The World Health Organization has recommended that the influenza vaccine for the include the following strains: A/New Caledonia/20/99 (H1N1)-like virus; an A/Wisconsin/67/2005 (H3N2)-like virus; and a B/Malaysia/2506/2004-like virus. Confirmation of the final composition of this year s vaccine will come in the annual NACI Statement on Influenza Vaccination which is usually released in the early part of the summer. Avian Influenza Update At the time of publication of this Update, the current Pandemic Alert Phase is Pandemic Alert Phase 3.0 (WHO = 3; Canada = 0). This phase is characterised by two or more confirmed human infections with a novel virus sub-type and no evidence of efficient and sustained human-to-human transmission. Patients presenting with influenza-like illness should be queried for travel history and tested for influenza, particularly those who have recently travelled or had Vaccine & CD Update Vol 13; Issue 2; Summer 2006

12 contact with travellers to any of the H5N1 avian influenza affected areas. Current travel advisories related to Avian influenza are posted to Nasopharyngeal Swabs Nasopharyngeal (N-P) swabs are a valuable tool in the diagnosis of a number of diseases including measles, mumps, pertussis, rubella, influenza and parainfluenza. They can also be used to diagnose rhinovirus, adenovirus, echovirus, coxsackievirus infections, Epstein-Barr virus, RSV (respiratory syncytial virus) and HSV (herpes simplex virus). The Health Department continues to receive inquiries regarding the ordering of nasopharyngeal swabs. The swabs must be ordered directly from the Public Health Laboratory in Hamilton by calling or from the Central Public Health Lab in Etobicoke by written request on letterhead sent by FAX to The laboratory will discard specimens if the correct procedure has not been followed. To ensure that the specimen is processed, here are some helpful reminders: 1) Use the thin wire-handled swab only. Do not use the cotton swab. 2) After the specimen has been obtained, place the tip of the wire swab into the liquid- filled container. 3) Clip the end of the wire so that it does not interfere with closing the cap. Ensure that the cap is securely closed. 4) Label swab with name and birth date of client. 5) Place the completed swab inside the biohazard pouch and the requisition in the exterior pocket 6) Refrigerate until sent to the lab for processing. New Diagnostics for TB Screening for tuberculosis is entering a new era. A new type of TB screening test, called the QFT-G (QuantiFERON-Gold) has been approved for use in the United States and may soon be available in Canada. How does it work? Blood samples are mixed with antigens and incubated for 16 to 24 hours. The antigens include ESAT-6 and CFP-10, proteins specific to M. tuberculosis complex. These antigens are not found in BCG strains or M. avium. If the patient is infected with M. tuberculosis, the patient s lymphocytes will recognize the antigens and release interferon-gamma (IFN-g) in response. The QFT results are based on the amount of IFN-g that is released. Advantages: only one visit is required results are available in 24 hours the test is more specific and can rule out reaction caused by BCG errors in planting and reading tests are avoided there is no booster effect can detect both active and latent infections (LTBI) Disadvantages blood samples must be processed within 12 hours of collection the effectiveness as a screening tool in young children and immunocompromised has not yet been determined the sensitivity for LTBI may be less than the TST there is limited lab and clinical experience. Use of the Quantiferon-Gold (QFT-G) Immigration screening to evaluate the possible reaction of a TST being from BCG rather than natural infection Screening of health care workers Contact investigation Correctional institutions Homeless population As with the TST, additional testing is needed to confirm LTBI and exclude active disease. Notice: Seminar for Community Nurses The fall session of Current Health Issues: A Seminar for Community Nurses will take place on Wednesday, October 4, 2006 from 7 to 9 p.m. Registration information and the agenda will be sent out in August. Halton Region Health Department Toll free: HALTON ( ) TTY Vaccine & CD Update Vol 13; Issue 2; Summer 2006