Varicella Epidemiology and Testing. Lexie Barber Varicella Epidemiologist November 2, 2018

Transcription

1 Varicella Epidemiology and Testing Lexie Barber Varicella Epidemiologist November 2, 2018

2 Varicella Reporting in Minnesota 2006: Schools required to report varicella outbreaks. Subset of schools reported individual cases of varicella. 2004: Minnesota School Immunization Law requirement of one dose of varicella vaccination for entry into kindergarten and 7 th grade. 2009: Minnesota School Immunization Law requirement of two doses for entry into kindergarten and 7 th grade. 2014: All students (k-12) in Minnesota required to have two doses. Beginning January 1, 2013: case based surveillance. Healthcare providers, schools, and childcares report suspected and confirmed cases to the Minnesota Department of Health (MDH). 11/9/2018 2

3 Reported Varicella Outbreaks in Minnesota Schools and Number of Students Involved No. of Cases No. of Outbreaks 70 Number of Cases Number of Outbreaks /9/2018 3

4 Varicella Annual Case Counts and Incidence in Minnesota No. of Cases Total Cases Incidence per 100, Incidence per 100, /9/2018 4

5 Varicella Cases by Age Group in Minnesota-2017 Number of Cases Number of Cases Incidence per 100,000 Persons < Age in Years Incidence per 100,000 11/9/2018 5

6 Varicella Case-Based Reporting in Minnesota MDH follow-up: Conduct phone interviews with case or case s parent/guardian, Notifies school, childcare, or exposed high risk contacts that may require PEP, Enters disease history into MIIC-only for lab confirmed cases. A rash description is essential for inclusion of cases in statistics and to inform recommendations for disease control. Laboratory confirmation is extremely important when notifying and making PEP recommendations. 11/9/2018 6

7 School Cases and Outbreaks Notification of classmates for a single case of varicella. Notification of school for a varicella outbreak: >5 cases of varicella that are related in place and epidemiologically linked. Symptom watch letters sent to parents of unvaccinated students. Specimen collection kits: designed for parents to use to test child for varicellaespecially important in confirming an outbreak if we haven t already. Can end up with large number of individuals notified, which can lead to a lot of rash illness being called varicella. This is another reason why it is important to test. 11/9/2018 7

8 Materials Provided to Parents Two-slide mailer 1 slide for dislodging loose scabs/crusts 1 slide with label for receiving scabs/crusts Buccal cell collection swab Combined instruction and informed consent document Prepaid padded mailing envelope 11/9/2018 8

9 Varicella in Unvaccinated Individual Generalized and pruritic rash Lasting about 5-7 days Macules Papules Vesicular lesions Crusts Mild fever and malaise may occur 1-2 days prior to rash onset, particularly in adults. In children, rash is usually the first symptom. 11/9/2018 9

10 Varicella in Vaccinated Individual More common than typical varicella disease Presents atypically Usually mild, shorter illness, and low or no fever <50 lesions with few or no vesicles Often fades rather than crusting over 25-30% of those vaccinated with 1 dose will have clinical features similar to those unvaccinated. Very difficult to clinically diagnose due to the mild presentation. Laboratory testing is important for confirming case and managing their contacts! Less contagious if < 50 lesions, but still need to notify contacts. 11/9/

11 Challenges in Clinical Diagnosis Breakthrough varicella more common-atypical presentation. Atypical hand, foot, and mouth disease (FHMD) more common (coxsackievirus A6). Rash may appear on arms, legs, truck, perioral regions, buttocks, and genitalia. Inconsistent diagnoses of varicella vs. HFMD. Exclusion and PEP recommendations differ greatly! Exclusion for Varicella: until rash crusts over/fades-can be 5-7 days. Large burden for parents to keep child out of childcare or school for this amount of time. Exclusion for HFMD: until 24 hours after fever stops. 11/9/

12 Challenges in Clinical Diagnosis Post exposure prophylaxis: Hand, foot, and mouth disease No PEP recommendations Varicella Varicella vaccine recommended within 5 days of exposure VariZIG for those at high risk for severe disease, up to 10 days post-exposure Pregnant women and Immunocompromised persons without evidence of immunity Newborns whose mothers have onset of varicella from 5 days before until 2 days after delivery and premature infants Notification: limits cry wolf problem in schools and child cares 11/9/

13 Varicella Outbreak Examples Varicella outbreak among infants in child care center, Aug.-Sept (N=9) Reporting to MDH Directly by health care provider (HCP) 1-2 By child care after parent relayed diagnosis by HCP 9 Clinical Diagnosis Specimen Collection Varicella 4 By HCP at time of visit 2 HFMD 2 By parent using kit supplied by MDH 5 HFMD vs varicella 2 None collected 2 Unknown 1 PCR Testing Specimens testing positive for VZV by PCR 7/7 Specimens testing positive for Enterovirus by PCR 0/6 11/9/

14 Philadelphia Department of Public Health Study Philadelphia Department of Public Health studied breakthrough varicella in single dose vaccine recipients: 411 suspected breakthrough cases laboratory tested: Confirmed VZV: 31% VZV ruled out: 45% Indeterminate: 24% Large burden on parents to stay home with child if it is not in fact chickenpox 11/9/

15 Other Skin Conditions Mistaken for Varicella Coxsackievirus (HFMD) Herpes simplex virus Follicultis Insect bites Impetigo Scabies 11/9/

16 Enhanced Varicella Project Since January 2017 Asked labs to submit specimens that were tested for varicella to the MDH lab in patients under 18 years old-both positive and negative. Two labs regularly submitting also including specimens submitted by parents using our testing kits and any specimens submitted by health care providers for regular VZV testing. Testing for VZV, as well as enterovirus, HSV-1, and HSV specimens submitted so far 44 cases excluded pediatric zoster 99 cases excluded after reviewing medical charts, did not have generalized rash 146 remaining specimens 11/9/

17 Enhanced Varicella Project 146 specimens submitted for VZV testing: 65 tested positive for VZV 19 tested positive for enterovirus 1 positive for HSV-1 61-negative for VZV, enterovirus, HSV-1, and HSV-2 Interested in getting more clinics involved in enhanced varicella surveillance. MDH provides free VZV testing. Can also provide collection materials. 11/9/

18 Why test? Rash is increasingly confused with other causes. Exclusion and PEP recommendations differ. Limits cry wolf problem in schools and child cares. Allows documentation of immunity in MIIC-so vaccine is not given unnecessarily. MDH provides PCR testing at no charge (IgM is not reliable and not recommended). Submitting clinical materials to MDH is now required. 11/9/

19 How to Test for Varicella Polymerase chain reaction (PCR)-preferred testing method for varicella. Polyester swab methods: Using a sterile needle, unroof the top of the vesicle. Using a sterile swab-vigorously swab the base of the lesion. Glass slide method: Rake the edge of the slide over the selected lesion-abrading the lesion to ensure skins cells are gathered onto the slide. Use swab to scrub the abraded lesion and collect the material collected on the edge of the slide. Crusts: With young children, asking them to help may make this less stressful. Use separate swabs for separate lesions. Crusts are excellent samples for PCR detection. Crusts can be lifted off of the skin and transferred into break resistant, snap-cap or screw-top tubes. IgM is not reliable and not recommended for confirming varicella disease. 11/9/

20 Barriers to Varicella Reporting and Testing Problems with diagnosis: unsure of disease control/follow up/statistical analysis when clinically diagnosed. Don t always have a good rash description. Triage lines/screening out potential cases and providing counseling over the phone: Reporting to MDH rarely occurs. Lost opportunity to do contact follow-up, disease control, and statistics. Could reporting be delegated? Other ideas? Clinically diagnosed cases often go unreported Varicella report form is readily available online: Cost of lab testing by PCR: Testing available at no charge at MDH. 11/9/

21 Minnesota Varicella Cases by Month, Number of Cases JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 11/9/

22 Varicella in Health Care Settings Follow standard precautions plus airborne precautions and contact precautions until lesions are dry and crusted. If negative air flow rooms are not available, isolate patient in closed room. Do not allow contact with those without evidence of immunity to varicella. Only staff with evidence of immunity should care for patients. 11/9/

23 Exposed Health Care Personnel Those with two doses of varicella vaccine: Monitor daily for days post exposure- fever, rash, or other symptoms suggestive of varicella. Remove immediately from patient care if symptoms occur. Those with one dose of varicella vaccine: Receive second dose of varicella vaccine-(provided 4 weeks have passed since first dose). Follow guidelines for HCP with two doses of varicella vaccine for monitoring. Unvaccinated health care workers: Potentially contagious from days after exposure-should be furloughed. Should receive post exposure prophylaxis (PEP) as soon as possible-within 3-5 days- may modify disease. Easier to ensure all health care providers have evidence of immunity to VZV at hire rather than after an exposure! Information should be documented and readily available at work location. 11/9/

24 Evidence of Immunity to Varicella Documentation of two doses of varicella vaccine. Laboratory evidence of immunity. Documentation of a diagnosis or verified history of varicella or zoster from a health care provider. *Birth before 1980 is not considered evidence of immunity for health care workers 11/9/

25 Thank you! Lexie Barber /9/

26 Measles and Clinical Response Cynthia Kenyon VPD Surveillance Supervisor November 2, 2018

27 Objectives Describe the importance of healthcare facility and public health partnership in order to effectively respond to a measles outbreak. Develop a plan for identifying healthcare facility exposures and initiating post-exposure follow-up action steps in a timely manner. Understand the complementary roles of healthcare and public health in implementation of disease control activities.

28 Measles (Rubeola) Fever, cough, coryza, conjunctivitis Maculopapular rash spreads from head to trunk to lower extremities Highly infectious, 90% attack rate in close contacts Contagious 9 days (4 days before/after rash onset) Vaccine preventable 93% effective with 1 dose at 12 mo 97% effective after 2 doses

29 Exposure sites for measles cases, Measles, MN, 2017 Measles cases by likely exposure site (N=75) School, 4 (5%) Unknown, 1 (1%) Community, 10 (13%) Childcare, 32 (43%) Household, 26 (35%) Healthcare, 2 (3%)

30 Outbreak Control Strategy Rapid identification + investigation of cases Decrease transmission Eliminate exposure in high risk settings Identify exposed persons + implement post-exposure prophylaxis Exclusion on as last resort Increase immunity through MMR vaccination Targeted outreach as needed Accelerate MMR schedule

31 Identifying Cases of Measles Have suspicion among patients presenting with Rash Fever Cough, Conjunctivits, Coryza (the three C s) TRAVEL Call MDH! Send Specimens to MDH

32 Could this be Measles? Amoxicillin allergy rash Measles rash Strep rash

33 Check Out Our Website Measles Toolkit

34 Minimize Exposures Ask patients with a febrile rash illness about a history of international travel, contact with foreign visitors. Mask suspect measles patients immediately. Do not allow suspect measles patients to remain in the waiting area or other common areas. Allow only health care personnel with documentation of 2 doses of MMR vaccine or laboratory evidence of immunity (measles IgG positive) to enter the patient s room. Close examination room for at least 2 hours after the possibly infectious patient leaves. Schedule suspect measles patients at the end of the day if possible. Notify the Minnesota Department of Health immediately! 11/9/

35 35

36 MDH Measles & Travel Find here in multiple languages: idepc/diseases/measles/thinkmeasl es/index.html What do you think when you think travel? Do you think International? Domestic? 11/9/

37 Healthcare Exposure Follow-up

38 PEP Window

39 Identify PEP window The clock is ticking!

40 Where was the patient? What department(s) and room(s) was the patient in? Where they in airborne isolation? What time were they there? What time were they in the waiting room, room a, room b, room c, etc. What other patients were near them? What staff saw them? 11/9/2018 Optional Tagline Goes Here mn.gov/websiteurl 40

41 Prioritizing Exposures Step 1: Determine MMR status EMR Minnesota Immunization Information Connection (MIIC) tab Primary Care Provider MDH contacted other state health departments Step 2: Prioritize by MMR status 1 st Priority 0 doses 2 nd Priority 1 dose 3 rd Priority 2 doses High risk (e.g., immunocompromised)

42 Contacting the Exposed 1st Priority = Phone calls Who is going to make the calls Who is going to answer when people call back Call bank with dedicated phone line 2 nd and 3 rd Priority = Letters Easy access to addresses (part of exposure report) Who is going to send the letters (stuffing hundreds of envelopes!) Templates ready to go MDH can help with this! Interpreters

43 Call Script Inform of exposure Verify immune status of patient Assess immune status of those accompanying the patient What to do next Where to go Challenges (e.g. transportation) Refusal or unable to reach Send to public health

44 Administering PEP Does your facility have IMIG and IVIG? Where will it be given? Who will give it? Extended hours? Family Education sheet Notifying PCP that PEP was given

45 So Many Questions, So Much To Think About Public Health is here to help MDH has template scripts, letters, and spreadsheets Some healthcare providers have a had a lot of experience, your healthcare colleagues are great resources too Public Health can help with capacity as needed 11/9/2018 Optional Tagline Goes Here mn.gov/websiteurl 45

46 QUESTIONS? Cynthia Kenyon, MPH /9/

47 A Plug Check out our website for other resources on testing For pertussis and mumps! PLUS Flu Near You! 11/9/

48 Pilot Project: Flu Near You Self-Swabbing Flu Near You is a participatory disease surveillance system that uses anonymous crowdsourced data to detect and visualize reports of influenza-like illness. Participants are asked weekly if they are experiencing any symptoms. This flu season, MDH has partnered with Flu Near You on a project to validate reports of influenza-like illness with self-collected nasal swabs. We are seeking volunteers willing to submit weekly reports and self-collect a nasal swab for testing at the MDH Public Health Lab. 1. Register at 2. Each Wednesday in November, Flu Near You will a link to sign up.