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B73 Measles

Key FactsPrint Version

This webpage is only intended for use by staff from the Los Angeles County Department of Public Health.Page Updated 11-13-24


  • Agent: Measles (rubeola) virus
  • Reservoir/Source: Human/Respiratory tract secretions and fomites.
  • Symptoms: Consider measles in patients of any age who have a fever ≥101 F, plus at least one of the 3 “Cs” (cough, coryza, or conjunctivitis) and a descending rash that starts on the face. The rash typically follows the onset of illness within 4 days. Atypical and modified rash can start on hands and feet.
  • Complications: Diarrhea, otitis media, pneumonia, encephalitis, subacute sclerosing panencephalitis, acute disseminated encephalomyelitis, keratitis, myocarditis, pericarditis, and death.
  • Differential Diagnoses: Kawasaki, rubella, scarlet fever, enteroviruses, and other febrile rash exanthems.
  • Incubation: From exposure to rash onset, 7-21 days with an average of 14 days.
  • Communicability and Transmission: From 4 days before onset of rash to 4 days after its appearance via direct contact with infectious droplets or by airborne spread.
  • Presumption of Immunity Criteria: See Box 2.
  • Specimen Collection/Lab Testing: Throat or nasopharyngeal (NP) swab, urine, and serum, see Box 1 for details.
  • Specific Treatment: Supportive care only; antiviral agent not available. Vitamin A supplementation may be beneficial for reducing measles severity and risk of complications.
  • Post-Exposure Prophylaxis: MMR or immune-globulin. See “Investigation of Asymptomatic Contacts to a Measles Case” for more details.
  • ACIP Recommended Vaccines: MMR and MMRV
  • Reportable Criteria: Report by phone immediately upon suspicion of measles: 888-397-3993 (for Los Angeles County).
    Do not wait for laboratory confirmation before reporting.
  • Report forms to be completed: Measles (Rubeola) Case Report (CDPH-8345), Measles Exposure Interview Form (Optional), and Measles Contact Line List
Investigation of a Suspect Measles Case
1. Measles Report Notification
  1. If the Vaccine Preventable Disease Control Program (VPDC) did not refer the suspect measles case to the Health District, the Health District must immediately call VPDC’s main line at 213-351-7800, ask to speak to the surveillance person on duty, and notify VPDC of the case.
  2. Within 24 hours of notification, VPDC will conduct the initial assessment of the case.
  3. If Health District follow-up is needed, VPDC will open the incident in IRIS and route to the Health District of case’s residence.
2. Establish Communication with Case
  1. If field support is needed, Health District commences investigation within 24 hours of case notification and completes remaining steps in this “Investigation of a Suspect Measles Case” section.
  2. Obtain all documents in the IRIS filing cabinet and read IRIS notes provided by the VPDC initial investigator, if available.
  3. Conduct case interview to complete Initial Assessment Form, if not yet completed. This can be done over the phone.
  4. Within 24 hours of case interview, send notification letter to case with isolation guidance, if not previously sent.
  5. If unable to reach the case by phone and case interview has not been completed, at least one home visit is required within 24 hours of receipt of case assignment. After 3 unsuccessful attempts within 24 hours, a second home visit is required within 48 hours of receipt of assignment.
  6. If all contact attempts are unsuccessful within 48 hours of receipt of assignment, consult with Public Health Nurse (PHN) Supervisor and Regional Medical Director (RMD) for immediate referral to PHI.
  7. At any point in the investigation, if the case becomes non-compliant with instructions to submit requested information or adherence to isolation/exclusion procedures, consult with PHN Supervisor and RMD immediately. VPDC (or CFS, if triaged to Health District) will serve isolation health officer order within 24 hours of knowledge of non-compliance.
3. Clinical Assessment of Case
  1. VPDC, or the Health District if triaged for field support, will review medical notes, Initial Assessment Form, and any other documentation in IRIS filing cabinet and notes/remarks to confirm the following:
    1. Fever onset date and duration
    2. Rash onset date and duration
    3. Rash onset location on body and progression on body over time
    4. Presence or recent history of “3 C’s” – cough, coryza, and conjunctivitis
    5. Case’s current immunocompromised status and at the time of exposure
  2. Determine from case and evaluating clinician if case had any of the following:
    1. An MMR vaccine within the last 3 weeks (document the number of doses and dates for all MMR vaccines received)
    2. Immune-globulin within the last year (document date)
    3. Antibiotics within the last 4 weeks (document antibiotic name, dosage, indication, treatment start date, and completion date)
4. Specimen Collection: Urine, Throat or NP, and Serum
  1. See Box 1 for collection equipment and timeline.
  2. The staff member(s) collecting specimens must have documented measles immunity (two documented MMRs or a positive measles IgG titer).
  3. Specimen collection can occur at Public Health Centers or elsewhere (such as private provider offices or case’s home). When possible, choose a setting that minimizes exposing other patients to the case. Ideally, schedule the case to come into the clinic at the start or end of the day to avoid possible exposure to other patients.
  4. Suspect measles cases should wear a high-grade medical mask and immediately be escorted to an airborne isolation room away from other patients. If an airborne isolation room is not available, a private room can be used. Otherwise, consider collecting the specimen outdoors, such as at the patient’s car.
  5. Do not use the exam room again until one hour after the case has left the room.
  6. Once specimens are collected, arrange for Public Health Lab courier to pick up specimen (see Box 1 Storage and Lab Requisition Forms).
  7. Immediately notify VPDC of specimens collected by emailing vpdc@ph.lacounty.gov or calling 213- 351-7800 and asking for the surveillance person on duty.
5. Isolation/Exclusion from Activity
  1. VPDC, or the Health District if triaged for field support, must isolate/exclude the case based on the following categories:

    Symptoms of febrile rash: Regardless of measles immunity status, the case should not attend school, participate in any social activities, use public transit, or attend public gatherings or venues until Public Health has determined that the case does not have measles.

    Confirmed to have measles by Public Health: Regardless of immunity status, the case must isolate until the 4th day after rash onset.

    Hospitalized: Prompt airborne isolation is required until the 4th day after rash onset. If case is immunocompromised, airborne isolation should be maintained throughout illness duration.
  2. An Off Work Notice may be considered to enforce exclusion from work. Consult PHN Supervisor and RMD if other institutional exposure isolation procedures, such as an isolation health officer order, is being considered.
6. Identify Exposed Contacts
  1. Determine dates of infectious period: 4 days before rash onset through 4 days after rash onset. Rash onset date is day 0.
  2. Exposure Definition: Sharing the same air space with a case -OR- having been present in these areas within 1 hour after the case leaves.
  3. Identify sites where the case visited while infectious. Use credit card receipts, calendars, and other tools to try to get a complete list of sites.
    1. The Measles Activity Log is an optional tool to help identify sites. The investigator may provide the log pre-filled with dates of the infectious period and ask the case to fill it out.
  4. Once all possible contacts have been identified and a measles diagnosis has been confirmed in consultation with VPDC, proceed to the section on “INVESTIGATION OF ASYMPTOMATIC CONTACTS TO A MEASLES CASE.”
7. Complete Case Report Form
  1. If case is confirmed, complete Measles Case Report Form (CDPH-8345) and upload it to the IRIS filing cabinet.
Investigation of Asymptomatic Contacts to a Measles Case
1. Obtain line lists from Exposure Sites
  1. Within 24 hours of case interview, VPDC will assign exposure sites based on location type to programs.
    1. Community exposure sites: VPDC or the Health District (if field support is needed).
    2. Healthcare facilities (exposed staff and patients): ACDC Healthcare Outreach Unit (HOU).
    3. Flight Exposure: VPDC coordinates with CDC/CDPH for line list.
  2. Assigned teams will immediately coordinate with exposed facilities to obtain a completed Measles Contact Line List. For schools, a copy of immunization records for exposed students and staff should also be requested. Within 24 hours of receiving completed line list(s), VPDC will determine which contacts will be routed to CFS for follow-up and triage to an assigned investigator in the Health District of residence.
    1. If a line list is not received within 48 hours:
      From a community site: VPDC will request a site visit from CFS-PHN or Environmental Health to obtain a completed line list.
      From a Healthcare Facility: ACDC- HOU may escalate request to Chief Medical Officer or conduct a site visit.
    2. Completed line lists should be sent via secure email to VPDC at vpdc@ph.lacounty.gov.
  3. Upon initial contact, all sites should be provided the public exposure notification flyer (available in English, Spanish, Chinese, and Armenian). Instruct sites to post flyers throughout the duration of the monitoring period (21-days after most recent exposure).
  4. Within 24 hours of initial communication, the assigned investigator will also provide a Facility Exposure Notification Letter to their assigned exposure sites.
  5. Throughout the investigation, the assigned investigator will provide their assigned sites with a daily list of individuals to exclude. VPDC will generate this list for distribution.
  6. If an exposure site becomes non-compliant at any point in the investigation, consult with PHN Supervisor and RMD to determine whether a Health Officer Order is warranted.
2. Establish Communication with Contact and Confirm Exposure
  1. For healthcare facilities, If ACDC-HOU cannot locate non-staff contacts (e.g., patients or visitors) within 24 hours, they will be routed to CFS for follow-up and triaged to an assigned investigator in the Health District of residence.
  2. Within 24 hours of notification of any contact investigation, the assigned investigator attempts to contact the contact.
  3. The assigned investigator interviews contact to determine the following critical information:
    1. Exposure setting
    2. Measles immunity status
    3. Risk status (high or low)
    4. Contact with persons at high risk of severe illness
    5. Signs and symptoms
  4. The Measles Exposure Interview Form is an optional tool to help guide the initial interview. Also see appendix (Figure 1 and Tables 1-3).
  5. After the interview, the assigned investigator sends contact the Exposed Individual Notification Letter with guidance on actions they will need to take until the end of the surveillance period.
  6. The assigned investigator should attempt to reach the contact at least once per 24 hours (for up to 72 hours) until contact is interviewed. If contact is not reached by phone, a home visit should be attempted within 48 hours. If contact is not reached after home visit attempt, consult with PHN Supervisor and RMD for immediate referral to PHI to obtain additional contact information. After at least 3 unsuccessful contact attempts over 72 hours (including at least 1 home visit attempt), record as lost to follow-up.
  7. If contact has not responded after 24 hours of initial contact attempt, the exposure site will be informed to exclude the individual from the site by the site's assigned point of contact (see section "1. Obtain Line Lists from Exposure Sites.").
3. Specimen Collection for Symptomatic Contacts
  1. If a contact reports symptoms at any point of the investigation, immediately notify VPDC by calling the VPDC main line at 213- 351-7800 and ask to speak with the surveillance person on duty.
  2. Immediately coordinate specimen collection for testing. See Box 1 for collection equipment and guidelines.
  3. Begin steps in “INVESTIGATION OF A SUSPECT MEASLES CASE.”
4. Determine Risk Level
  1. High-risk contacts are those who may experience severe illness if infected or to whom transmission potential is high.
    Examples of high-risk individuals:
    • Pregnant women
    • Infants <12 months of age
    • Immunocompromised persons
    • Household contacts
    • Persons with prolonged exposure (e.g., rideshare driver of the case)
    • Persons who work in high-risk settings. High-risk settings include locations in which transmission risk is high (e.g., setting with a large number of measles susceptible persons or an infant care setting). Healthcare contacts who are not healthcare workers and are not otherwise high risk can be followed up as low risk.
  2. Low-risk contacts are those who are not at high risk of experiencing severe illness or to/from whom transmission potential is not high.
    Examples of low-risk individuals:
    • Immunocompetent
    • ≥12 months of age
    • Not pregnant
    • Not a healthcare worker
    • Not a household contact
5. Determine Immune Status
  1. High-risk contacts who self-report measles immunity have 24 hours from initial interview to produce evidence of immunity (see Box 2).
  2. Low-risk contacts have 48 hours from initial interview to meet presumptive immunity criteria (see Box 2).
  3. If immunity criteria are not met within specified time frame, the investigator will attempt to collect specimen for IgG titers. An attempt to collect specimen for IgG titers should occur within 24 hours for high-risk contacts and within one business day for low-risk contacts. Contacts should be advised to quarantine while IgG results are pending. Contacts may also go to their private healthcare providers for IgG titers if they prefer.
  4. If IgG titer result is negative, the assigned investigator should offer MMR to contact.
  5. If contact refuses IgG blood draw and does not produce evidence of immunity, the investigator should provide the contact with isolation/exclusion guidance and symptom monitoring (see section "7. Quarantine/Exclusion from High-Risk Settings").
6. Post-Exposure Prophylaxis (PEP)
  1. The administration of MMR vs. immune globulin (IG) for PEP depends upon time since exposure to case, age, and risk status. See appendix for more details. MMR is acceptable PEP when all the following criteria are met:
    • <72 hours have passed since first exposure to case
    • ≥6 months of age (though IG is preferred for infants 6-11 months)
    • 1 or no documented MMR vaccines or negative IgG

    Immune Globulin (IG) is acceptable PEP when the following criteria are met:

    • ≤6 days have passed since first exposure to case (can be given ≤6 days from last exposure to prevent infection but not considered adequate PEP for contact management)
    • Susceptible persons not eligible for MMR -or- immunocompromised persons regardless of immune status
  2. The assigned investigator will recommend PEP for eligible contact and coordinate with DPH Clinic Services to offer PEP at a Health Center for those unable to receive it through their healthcare providers.
  3. A person who receives PEP may discontinue quarantine but must still be excluded from high-risk settings (e.g., healthcare settings, infant daycare) for 21 days after last exposure date.
7. Quarantine/Exclusion from High-Risk Settings
  1. Quarantine refers to a period of home isolation. Exclusion refers to high-risk settings and can apply to persons who are not otherwise quarantined. See appendix for more details on quarantine and exclusion by contact risk status.
  2. If contact does not meet immunity criteria (Box 2) within allotted time frame (24 hours for high risk and 48 hours for low risk), the assigned investigator will provide quarantine guidance and, if applicable, exclusion guidance.
    • An Off Work Notice may be sent to enforce exclusion from work.
    • High-risk contacts may be released from quarantine if they receive adequate PEP or provide evidence of immunity. However, they still must be excluded from high-risk settings.
  3. Low-risk contacts who work in or attend a high-risk setting and have only 1 documented MMR dose OR meets presumption of immunity do not require quarantine but require exclusion from the high-risk setting. If they do not have at least 1 documented dose of MMR or do not meet presumption of immunity, they require both quarantine and exclusion.
  4. Contacts who receive IG PEP should be excluded from high-risk settings for 28 days after last exposure.
  5. If a contact is non-compliant, consult with PHN Supervisor and RMD to determine if a Health Officer Order is warranted.
8. Symptom Monitoring
  1. Symptom monitoring continues for 21 days, 28 days for those who receive IG PEP, after most recent exposure to an infectious case. See appendix (Table 1-3) for monitoring by risk status/setting.
  2. Active monitoring is daily monitoring via phone call or text throughout the surveillance period. The assigned investigator actively monitors contacts in the following groups:
    • High-risk contacts without documentation of immunity
    • Low-risk contacts who do not meet presumption of immunity
    • Persons who receive IG PEP until day 21 (should then passively monitor during days 22-28)
  3. Passive Monitoring is required for all contacts who do not require active monitoring. The investigator advises contacts to monitor for symptoms and reach out if any develop. Notification should be sent on the last day of the surveillance period to inform contacts that the surveillance period has ended.
Boxes, Appendix, & Resources
Box 1: Measles Specimen Collection & Lab Testing

Collect all specimens in consultation with VPDC. Real-time polymerase chain reaction (RT-PCR) testing can be done at the Public Health Lab or certain commercial labs.

Testing for Patients with a Rash

  • Throat or NP swab for RT-PCR
    • Timeline: Collect within 2 weeks of rash onset.
    • Equipment
      • Use sterile synthetic (non-organic) swab (e.g., Dacron)
      • Place swab after collection into liquid viral or universal transport medium.
    • Urine for RT-PCR
      • Timeline: Collect within 2 weeks of rash onset
      • Equipment:
        • Collect 10-50 ml urine in a sterile container from the first part of the urine stream. The first morning void is ideal.
    • Serum for IgM test for recent infection or recent vaccination
      • Timeline: Acute serum optimally collected at least 72 hours after rash onset
      • Equipment:
        • Collect 7-10 ml of blood in a serum separator tube (SST, red-gray rubber stopper or gold plastic stopper).
        • Use capillary blood 2-5 tubes (finger or heel stick) for pediatric patients.
        • If acute IgM is negative, a convalescent serum specimen may be requested 14-28 days later.

Immunity Testing for Asymptomatic Patients

  • Serum for IgG only
    • Equipment is same as IgM serum test

Storage and Lab Requisition Forms

Box 2: Presumption of Immunity Criteria

Contacts may be presumed immune if they meet any of the following criteria:

High Risk

  • Documentation of two doses of measles vaccine given 1968 or later, separated by at least 28 days, with the first dose on or after first birthday
  • A positive IgG test for measles
  • Laboratory confirmation of previous disease

Low Risk

  • Any high-risk presumptive immunity criteria.
  • Born in the U.S. prior to 1957
  • Born outside the U.S. prior to 1970 AND moved to the U.S. in 1970 or later
  • Born in any country in 1976 or later AND attended a U.S. primary or secondary school
  • Have written documentation with date of receipt of at least one dose of measles- containing vaccine given on or after first birthday in 1968 or later
  • Have a documented IgG positive test for measles
  • Served in the U.S. armed forces
  • Entered the U.S. as a permanent U.S. resident or became one in 1996 or later (i.e., have a “green card”)
Figure 1: Measles Contact Management Algorithm
Contact Management

* For measles contacts who have tested measles IgG negative or equivocal in a commercial lab, VPDC should be consulted regarding potential retesting at DPH PHL. If a contact tests positive for IgG at PHL or a commercial lab, consider them to be immune.
‡ Implement quarantine from day 7 after first exposure through day 21 after last exposure. If symptoms consistent with measles develop, the exposed person should be isolated and tested.
§ Exclude from high-risk settings (e.g., childcare facilities with infants and healthcare facilities; see definition above) from day 7 (day 5 for healthcare workers in healthcare settings) after first exposure through day 21 after last exposure. Those who have received IG should exclude through day 28 after last exposure.
‡‡ If it can be done rapidly, it is recommended that pregnant persons be tested for measles IgG prior to administering IGIV if it is likely that they have received vaccine or had disease. If an exposed pregnant person is IgG negative or IgG equivocal or has unknown status and IgG test results (or retest at VRDL) will not be known by day 6 after exposure, administer IGIV.
‡‡‡ A self-reported history of measles disease without documentation is not acceptable as a presumption of immunity. See page 6 for presumption of immunity criteria. If a low-risk contact has a measles IgG negative or IgG equivocal result, and subsequently provides documentation of two doses of MMR vaccine, base public health decisions on the two documented doses of MMR vaccine, i.e., presume immunity.

Figure 2:

Figure 2: Immune Globulin (IG) Dosage for Measles Exposure

   
Indications		    
Dose		    
Interval before MMR vaccine administration

Infants <12months of age
0.5 ml/kg IM
(max dose = 15mL)
6 months   

Susceptible immunocompetent contacts <30 kg/66lbs5 		   
0.5 ml/kg IM
(max dose =15mL)		    
6 months

Pregnant women without evidence of immunity 		   
400 mg/kg IV (intravenously)   
8 months and nonpregnant
   
Severely immunocompromised persons6 (also see Section VI)		    
400 mg/kg IV (intravenously)   		    
8 months   

1IGIM should be administered at room temperature and within 6 days of exposure.
2IG should be administered to susceptible infants and children <30 kg and high-risk persons (pregnant women and severely immunocompromised persons). See footnote 7.
3IGIM can be given to any person <30 kg who lacks evidence of measles immunity, but priority should be given to persons exposed in settings with intense, prolonged, close contact (e.g., household, child care, classroom, etc.) or persons who are more likely to develop severe measles (infants, immunocompromised children).
4The maximum intramuscular dose of IG is 15 ml for all persons.
5Persons weighing >30 kg/66 lbs are unlikely to receive an adequate amount of measles antibody from IGIM.
6Severely immunocompromised patients who are exposed to measles should receive IGIV prophylaxis regardless of immunologic or vaccination status because they might not be protected by the vaccine. Per CDC and IDSA, persons with high-level immunosuppression include those:

  • with combined primary immunodeficiency disorder (e.g., severe combined immunodeficiency);
  • who are receiving cancer chemotherapy;
  • on treatment for ALL within and until at least 6 months after completion of immunosuppressive chemotherapy;
  • within 2 months after solid organ transplantation;
  • who have received a bone marrow transplant until at least 12 months after finishing all immunosuppressive treatment, or longer in patients who have developed graft-versus-host disease;
  • with HIV infection with a CD4 T-lymphocyte count <200 cells/mm3 (age >5 years) and percentage <15 (all ages) (some experts include HIV-infected persons who lack recent confirmation of immunologic status or measles immunity);
  • receiving daily corticosteroid therapy with a dose ≥20 mg (or >2 mg/kg/day for patients who weigh <10 kg) of prednisone or equivalent for ≥14 days; and
  • receiving certain biologic immune modulators, that is, a tumor necrosis factor-alpha (TNF-α) blocker or rituximab

After HSCT, duration of high-level immunosuppression is highly variable and depends on type of transplant (longer for allogeneic than for autologous), type of donor and stem cell source, and post-transplant complications such as graft vs host disease (GVHD) and their treatments.

Table 1: Follow-Up of High-Risk Measles Contacts
High-risk contacts (persons with potential for severe illness if infected or to whom the transmission potential is high) IgG testing*
 PEP† Quarantine if no PEP‡ Exclusion Monitoring§
Unvaccinated infants <6 months of age No IG only Yes Yes** Active
Unvaccinated infants 6-11 months of age†† No MMR or IG‡‡ Yes Yes** Active
Pregnant persons without 2 documented MMR vaccine doses or serologic evidence of immunity‡‡ Yes* IG only Yes Yes** Active
Severely immunocompromised§§ No IG only Yes Yes** Active
Household contact or contact with prolonged exposure without 2 documented MMR vaccine doses or serologic evidence of immunity Yes* MMR or IG*** Yes Yes** Active
Immunocompetent contact with 2 documented MMR vaccine doses or serologic evidence of immunity No No No No Passive

* For measles contacts who have tested measles IgG negative or equivocal in a commercial lab, VPDC should be consulted regarding potential retesting at DPH PHL. If a contact tests positive for IgG at PHL or a commercial lab, consider them to be immune.
† Contacts at high risk of severe infection (severely immunocompromised people, unvaccinated infants, and susceptible pregnant persons) should receive IG PEP within 6 days or less from the date of last exposure to measles.
‡ Implement quarantine from day 7 after first exposure through day 21 after last exposure. If symptoms consistent with measles develop, the exposed person should be isolated and tested.
§ Exclude from high-risk settings (e.g., childcare facilities with infants and healthcare facilities; see definition above) from day 7 (day 5 for healthcare workers in healthcare settings) after first exposure through day 21 after last exposure. Those who have received IG should exclude through day 28 after last exposure.
** Exclude from high-risk settings (e.g., childcare facilities with infants and healthcare facilities; see definition above) from day 7 (day 5 for healthcare workers in healthcare settings) after first exposure through day 21 after last exposure. Those who have received IG should exclude through day 28 after last exposure.
†† MMR vaccine can be given as PEP within 72 hours or less from the time of exposure to persons >6 months of age who do not have contraindications for MMR vaccine. IMIG can be given as PEP for exposed infants <12 months of age <6 days from exposure. Persons >12 months of age who may have been vaccinated or had disease and receive MMR vaccine as PEP should have blood drawn and tested for measles IgG if measles IgG status is unknown at the time of MMR administration.
‡‡ If it can be done rapidly, it is recommended that pregnant persons be tested for measles IgG prior to administering IGIV if it is likely that they have received vaccine or had disease. If an exposed pregnant person is IgG negative or IgG equivocal or has unknown status and IgG test results (or retest at VRDL) will not be known by day 6 after exposure, administer IGIV.
§§ Refer to CDC and IDSA guidance for high-level immunosuppression criteria.
*** IGIM can be considered for susceptible persons in this category weighing <30 kg (<66 pounds). There is no recommendation for IGIM in susceptible persons >30 kg (≥66 pounds). MMR PEP is preferred if <72 hours of exposure. IGIV is not recommended for low-risk contacts weighing ≥30 kg (≥66 pounds).

Table 2: Follow-Up of Measles Contacts Who Work in A High-Risk Setting
Contacts who work in a healthcare setting or other high-risk setting IgG testing* PEP Quarantine if no PEP‡ Exclusion Monitoring
High-risk for severe disease due to personal medical history
and without 2 documented MMR vaccine doses or serologic evidence of immunity		 See Table 1
Low risk for severe disease and with 1 documented MMR vaccine dose
and no serologic evidence of immunity		 Yes MMR No Yes** Active
Low risk for severe disease and with no documented MMR vaccine doses
and no serologic evidence of immunity		 Yes MMR Yes Yes** Active
With 2 documented MMR vaccine doses
or serologic evidence of immunity		 No No No No Passive

* For measles contacts who have tested measles IgG negative or equivocal in a commercial lab, VPDC should be consulted regarding potential retesting at DPH PHL. If a contact tests positive for IgG at PHL or a commercial lab, consider them to be immune.
** Exclude from high-risk settings (e.g., childcare facilities with infants and healthcare facilities; see definition above) from day 7 (day 5 for healthcare workers in healthcare settings) after first exposure through day 21 after last exposure. Those who have received IG should exclude through day 28 after last exposure.

Table 3: Follow-Up of Low-Risk Measles Contacts
Low-risk contacts (immunocompetent
persons, persons >12 months of age, not pregnant,
not a healthcare worker, not a household contact)		 IgG testing* PEP Quarantine if no PEP‡ Exclusion Monitoring§
Two documented doses of MMR vaccine (3% will be susceptible) No No No No Passive
Known to be measles IgG positive (<1% will be susceptible)
Meets presumption of immunity criteria (including 1 documented MMR dose) If desired MMR if desired No Yes** Passive
Unknown or no documentation of vaccination or
immune status, without presumption of immunity†††		 Yes* MMR Yes Yes** Active
Prior measles IgG negative test result*,†††
Known to be unvaccinated††† No MMR Yes Yes** Active

* For measles contacts who have tested measles IgG negative or equivocal in a commercial lab, VPDC should be consulted regarding potential retesting at DPH PHL. If a contact tests positive for IgG at PHL or a commercial lab, consider them to be immune.
‡ Implement quarantine from day 7 after first exposure through day 21 after last exposure. If symptoms consistent with measles develop, the exposed person should be isolated and tested.
§ Exclude from high-risk settings (e.g., childcare facilities with infants and healthcare facilities; see definition above) from day 7 (day 5 for healthcare workers in healthcare settings) after first exposure through day 21 after last exposure. Those who have received IG should exclude through day 28 after last exposure.
** Exclude from high-risk settings (e.g., childcare facilities with infants and healthcare facilities; see definition above) from day 7 (day 5 for healthcare workers in healthcare settings) after first exposure through day 21 after last exposure. Those who have received IG should exclude through day 28 after last exposure.
††† See pages 3-4 for “Presumption of Immunity Criteria for Low-Risk Contacts”. A self-reported history of measles disease without documentation is not acceptable as a presumption of immunity. If a low-risk contact has a measles IgG negative or IgG equivocal result, and subsequently provides documentation of two doses of MMR vaccine, base public health decisions on the two documented doses of MMR vaccine, i.e., presume immunity.

Resources

Virtual Trainings:

Acute Communicable Disease Control Manual (B73):



Public Health has made reasonable efforts to provide accurate translation. However, no computerized translation is perfect and is not intended to replace traditional translation methods. If questions arise concerning the accuracy of the information, please refer to the English edition of the website, which is the official version.

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