TABLE.

Number of contacts^* exposed to an MMR-vaccinated health care worker^† with measles, by age group and MMR vaccination status — Maricopa County, Arizona, 2015

Age group	Total	Immunocompromised	History of measles disease	MMR vaccination status
				≥1 dose	No doses	Unknown
0–11 months	21	0	0	0	21	0
1–17 years§	210	9	0	166	8	27
≥18 years§	228	0	2	145	2	79¶
Unknown	19	0	0	13	0	6
Total	478	9	2	324	31	112

Abbreviation: MMR = measles, mumps, and rubella.

^*Includes only patients and their family members.

^†Health care worker had documented receipt of two MMR doses, but history of negative measles IgG serology test results.

^§Includes 50 persons aged 1–17 years and one person aged ≥18 years using the Arizona State Immunization Information System (ASIIS) records for MMR history; any ASIIS records with no MMR vaccine history were considered unknown.

^¶Fifty-one patients (among 47 families) could not be contacted; assumed one adult accompanied each patient or family of patients for siblings (i.e., the parent or guardian).