Measles Disease Containment: …but I’m Sure I was Vaccinated” Diane Portnoy, MPH Communicable Disease Control Unit San Francisco Department of Public Health July 29, 2010

Measles Learning Objectives  Be familiar with clinical manifestations of measles  Be aware of the disease control actions needed to stop the spread of measles  Understand how clinicians and public health work together to stop spread of measles

Symptoms of Measles  Incubation: days (range 7-18)  Prodrome: fever (up to ), malaise, cough, coryza, conjunctivitis  Rash: starts 1-4 days after prodrome  Erythematous, maculopapular, becomes confluent  Starts on face/head, spreads down back & trunk, then out to extremities  Koplik spots  Lasts 5-6 days, fades in order of appearance

Measles Rash Photos courtesy of Centers for Disease Control and Prevention

Measles: clinical features  Approximately 30% of reported measles cases have complications  Complications are more common in children < 5 years of age and adults ≥ 20 years of age  Complications (US): diarrhea (8%), otitis media (7%), bronchitis, pneumonia (6%), encephalitis (0.1%), death (0.2%)  Milder presentation (modified measles) if vaccinated  Atypical measles—rash progresses in opposite order—in persons who rec’d IG or newborns who rec’d maternal antibody  No specific treatment

Epidemiology of Measles  Infectious Period: 4 days before through 4 days after rash onset  Transmission by respiratory route  Droplet and airborne precautions  Infectious respiratory droplets stay suspended in air for up to 2 hours  90% attack rate  >95% measles vaccine coverage required to stop outbreak  Two doses of measles containing vaccine needed: 95% immunity (range 90% - 98%)

Measles Timeline  Timeline used during measles investigation to determine potential & actual contacts.

Index Case  SF resident (Case A) *Believed previously vaccinated for measles  Had contact with a known measles case on Jan. 17, 2009 while traveling in England  Flew back to U.S. on Jan. 20, 2009  On Jan. 25, 2009, 8 days after contact, developed measles symptoms: - malaise & fever followed by descending rash - cough developed Jan. 26, 2009

First Response January 27, 2009  Case A called children’s pediatrician and was diagnosed with measles over the phone.  Pediatrician immediately called SFDPH  That evening, Case A & family were interviewed/ examined by the Communicable Disease on-call MD.  Specimens were obtained for laboratory testing: Case A: NP swab and blood (serology) Spouse: blood (serology)  Two Children: both unvaccinated, no specimens sent  Case A isolated. Spouse & Children quarantined.  Parents counseled to provide Immune globulin and/or vaccination for children. Initially refused.

Results & Response January 28, 2009 Case A: NP specimen: (+) measles Serology: IgM+ and IgG- Spouse: Serology: immune IgG+ Preliminary case & contact investigation: multiple potential exposures of susceptible persons Activation & Notification of Infectious Disease Emergency Response Protocol initiated

Defining who is at Risk  A Contact: during the infectious period either: 1. Lived with the case OR 2. Shared air space for up to 2 hrs after the unmasked case was present AND is:  Susceptible to Measles (i.e. answers “No” to all the following): *Born before 1957 *Documentation of 2 doses of measles vaccine *History of MD documented measles infection *Laboratory evidence of measles immunity

Timeline: Case A *Infectious Period 4 days before & 4 days after appearance of rash = 8 days total Case A exposed ( to known measles case) Case A develops rash Visited large office, 1 hr : 64 people Visited religious ceremony,10 min: ~10 people 17 * * Tutored students in home, 1 hr: 3 people Contractor worked at home, 2 hrs: 1 person Household, ongoing exposures: 5 people Case A isolated Case A develops cough January February

Timeline: Case B & C *Infectious Period 4 days before & 4 days after appearance of rash = 8 days total Party A, several hrs:103 people Sunday School, couple hrs: 25 people Home visitors, < 1 hr : 3 people Case B & C quarantined in evening Case B develops rash Case C develops rash JanuaryFebruary Case B & C’s exposures start at beginning of Case A’s infectious period “Vaccinated” Home visitor, 10 min: 1 person Case B &C given IgG at home Exposures School A Classmates & Staff, many hrs: 18 people Children in After-school Program B, several hrs: 51 people

CaseContact Group Exposure Duration # People # SusceptibleOther information AHouseholdOngoing52 ATutored students 1 hr31 ALarge office1 hr + 2 hrs64UnknownMostly foreign born adults AReligious ceremony 10 min + ? 2 hrs ? ~10UnknownLarge open space B & CParty ASeveral hrs103Unknown B & CSunday school Several hrs25Many kids unvaccinated BSchool AMany hrs18Many kids unvaccinated B & CAfter school program Several hrs51Many kids unvaccinated B & CHome visitors< 1 hour4Adults Summary of Initial Info from Case & Contact Investigation

Response Activities  Identification and verification of disease  Collection of specimens for diagnosis (Cases A, B & C)  Case and contact investigation  Of 283 potential contacts, 62 determined to have been exposed (actual contacts).  Assessment of contacts’ immune status  Phone conversation  Collection of vaccination or medical records  Serology (collection, send to CDPH for testing)

Response Activities - 2  Isolation and Quarantine  Orders served in person from Jan. 29- Feb. 1, 2009  Issued to individuals meeting case or susceptible contact definitions  Active symptom surveillance of persons in quarantine  Enhanced passive surveillance with Health Alert to clinicians  Phone information line  Data Collection

Final Numbers # Confirmed Cases3 (1 adult, 2 children) # Potentially Exposed283 # Confirmed Exposed62 # Individuals Tested20 # Placed in Isolation3 # Placed in Quarantine27 # Placed under Active Surveillance 13

Effective Actions & Successes  Immediate notification by pediatrician!!!  Immediate isolation of Case A and quarantine of children (Cases B & C) by SFDPH.  Rapid testing by VRDL at CDPH.  Administration of IG likely ameliorated disease in Case B & C and may have prolonged their incubation period.  Only 3 cases!!!

The Personnel Costs of a Small Response Total Person Hours = 1,657 Participating Organizations: SF Department of Public Health  Communicable Disease Control & Prevention Section  Community Health Programs  STD Clinic California Department of Public Health  Immunization Branch  Viral & Rickettsial Diseases Lab

From Measles to Money: The Cost of a Small Response Total Person Hours = 1,657 Participating Organizations: SF Department of Public Health (CDCP, Community Health Programs, Sexually Transmitted Diseases and SF General Hospital) Cost Personnel 91,059 Supplies 7,042 $ 98,101!!!

Policies and Recommendations impacting the Scope of our Response  In the setting of limited resources, is there a way to prioritize follow-up of contacts?  Is the presence or absence of cough in the case predictive?  Is the quality of ventilation in the space where exposure occurred predictive?  Is the country of birth of the contact predictive of immunity?  Recommendation for duration of quarantine period varied for single cases versus outbreaks:  18 days (single case guidance) vs.. 21 days (outbreak guidance)  Effect of Immune globulin on disease course  Does it prolong incubation period? Should it extend quarantine?  We extended quarantine period to 28 days as per CDPH guidance.

What does the data show?  Cough as predictor of infectiousness  Ventilated space as predictor of disease spread  Country of birth: are individuals born in countries were measles is endemic likely to be immune?  Duration of quarantine period: 21 vs. 18 days  Effects of Immune globulin on infectious & incubation period

What’s in store for our next response to a measles case?  In the setting of a well confined outbreak, with no new cases, use 18 day quarantine period, rather than 21.  Promote immune globulin when indicated, in the setting of pros/cons of extended quarantine period.  Created “Tiered-Response” to follow-up of contacts.

Proposing a Tiered-response: contacts to a case of Measles Factors to evaluate when prioritizing contact investigations:  Likelihood of transmitting disease to susceptible and/or vulnerable populations if the contact develops measles  Likelihood of susceptibility  Likelihood of effective exposure  Risk of severe complications of measles disease  Feasibility of locating contacts

Proposing a Tiered-response: contacts to a case of Measles Priority #1: Settings for contact investigation High level of exposure High proportion of susceptible persons or persons at high risk of severe complications Priority #2: Identify (susceptible) contacts who are most likely to transmit measles to other susceptible high risk persons Priority #3: Assess likelihood that contact in SOS is susceptible to measles (age, history of vaccination, etc) Priority #4: Contacts whose SOS status is unknown Priority #5: Contacts not in an SOS are last priority for investigation

Additional Resources developed by SFDPH Remind Clinicians to:  Immediately Report to CDCU  Implement Infection Control  Coordinate Diagnostic Testing with CDCU  Isolate suspect Case  Help identify exposed contacts

Final Thoughts….  Measles cases are only a plane ride away.  Early Reporting by clinicians is key!  Prevent cases by vaccinating.  2 doses MMR for all school students, students in post-high school educational facilities, medical facility personnel, int’l travelers at least 12 months old  Other adults w/o evidence of immunity : 1 dose  Keep immunization records!!!  Yourself, your family, your staff, your clients  Emphasize the importance of IZ records  Immunization registries and campaigns may help in the future

Thank you:  Susan Fernyak, MD, MPH  Karen Holbrook, MD  Sandra Huang, MD  Disease Control Team & other CDCP Staff  Other SFDPH Staff  CDPH Staff: Iz Branch & VRDL