Campus Alert Archive
Cal State LA

2,000 Daily Library Visitors, No Sign-In Sheet: Cal State LA's Measles Quarantine Nightmare

CAdisease outbreakadvisorymedium confidence
Confirmed Threat

On April 25, 2019, California State University, Los Angeles notified the campus that a measles-positive individual had been in the campus library on April 11, 2019 from 11 a.m. to 3 p.m., triggering an LA County Department of Public Health quarantine order affecting initially 198 students and staff. Because the library received approximately 2,000 visitors per day with no sign-in requirement, the quarantine order rapidly expanded to 656 individuals who could not prove immunity.

Alerts
2
Response
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Killed
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Injured
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Institution
California State University, Los Angeles
Public Masters · CA
~27,000 studentsCal State LA Emergency Notification
Confirmed Timeline

Alert Sequence

2 messages in sequence

Some alert texts below are approximate reconstructions from news coverage, not confirmed verbatim transcripts. Reconstructed texts are shown in italic with a dashed border. Verified verbatim texts have a solid border and are marked accordingly.

INITIAL ALERTEmail
Approximate reconstructionReconstructed from Washington Post and NPR reporting on the April 25 joint county-university announcement952 chars
California State University, Los Angeles is alerting students and staff that a person with confirmed measles was on campus on April 11, 2019, from 11:00 a.m. to 3:00 p.m. in the university library. The Los Angeles County Department of Public Health has issued a quarantine order for individuals who were present in the library during that time and cannot show proof of measles immunity. If you were in the library during those hours on April 11, please do not come to campus. Contact the Student Health Center or your health care provider immediately to provide documentation of measles immunity (two doses of MMR vaccine or a positive measles titer). Measles is one of the most contagious viruses known; a single infectious person can infect up to 90% of non-immune close contacts. Symptoms include fever, cough, runny nose, red eyes, and a distinctive rash. If you develop symptoms, call before visiting a medical facility to prevent exposing others.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

The exposure date of April 11 -- two weeks before the public announcement on April 25 -- reflects the epidemiological reality that measles may have already spread during the 14-day window between exposure and notification.
The library's 2,000 daily visitors without a sign-in requirement was identified as the key contact-tracing barrier; the final quarantine order of 656 persons reflects only those who could be identified through other records.
Measles' extreme transmissibility (basic reproduction number R0 = 12-18) means a single undetected case in a public building can generate multiple secondary cases in non-immune individuals -- the exact dynamic playing out simultaneously at both Cal State LA and UCLA.
UPDATEEmail
Approximate reconstructionReconstructed from Washington Post 'The Latest' coverage of the expanding Cal State LA quarantine678 chars
An update on the measles situation at Cal State LA: The quarantine order has been expanded to 656 students and staff who were in the library on April 11 and cannot provide proof of measles immunity. Proof of immunity includes documentation of two MMR vaccine doses, a positive measles blood titer, or birth before 1957 (when measles was widespread and most people developed natural immunity). Those under quarantine must remain home until they provide this documentation or the exposure risk period ends. The Student Health Center is available to help verify immunization records. We recognize this is disruptive and appreciate your patience as we work to protect public health.

This text has been reconstructed from news coverage and may not reflect the exact original wording.

The quarantine grew from 198 to 656 persons as records were reviewed and additional exposures identified -- illustrating how contact tracing in a high-traffic, low-documentation public space can rapidly scale a quarantine order.
The inclusion of birth before 1957 as an alternative to documented vaccination reflects that pre-vaccine-era birth cohorts typically acquired natural measles immunity in childhood and are considered immune without documentation.
The quarantine requirement -- stay home and provide proof of immunity -- is enforceable under California public health law and LA County's emergency powers; non-compliance could result in legal sanctions.
Context

Background

Cal State LA's April 2019 measles quarantine was part of a broader LA County measles emergency that simultaneously struck UCLA, making it one of the most high-profile campus measles responses in recent US history. The exposure occurred in the campus library on April 11 -- two weeks before the public announcement on April 25 -- as a measles-positive individual spent four hours in a space with approximately 2,000 daily visitors and no sign-in requirement. This anonymity meant that contact tracing could only reach those identifiable through other records, ultimately producing a quarantine order for 656 students and staff who could not prove immunity. The 2019 national measles resurgence was the worst since the disease was declared eliminated from the US in 2000, with over 700 cases reported from January through April -- driven by unvaccinated communities and international travel. NPR reported that LA County issued both isolation and quarantine orders, invoking emergency public health authority. Cal State LA serves a predominantly Hispanic/Latino student body with significant representation of first-generation college students, a demographic that includes some members of communities with lower vaccination rates -- a structural factor in the outbreak's reach.
Analysis

Key Findings

The library's approximately 2,000 daily visitors without a sign-in requirement was the primary contact-tracing barrier; the final quarantine of 656 was limited to those identifiable through other records
The quarantine grew from an initial 198 to 656 persons as records review expanded the identified contact pool -- illustrating how undocumented public-space exposure scales a measles quarantine
A two-week gap between the April 11 exposure and the April 25 announcement reflects the typical timeline: incubation (7-14 days to first symptoms), clinical diagnosis, laboratory confirmation, and contact tracing each add time
The quarantine order required individuals to remain home until providing proof of immunity (two MMR doses, positive titer, or pre-1957 birth) -- enforceable under California public health law
Outcome
656 students and staff were placed under quarantine orders, required to stay home until they provided evidence of measles immunity or the risk period expired. The campus library's lack of a sign-in system complicated contact tracing significantly.
Provenance

Sources

  1. News
    Two LA universities quarantine more than students and staff for measles outbreak -- Washington Post
    washingtonpost.com
  2. News
    The Latest: Cal State LA measles quarantine grows to 656 -- Washington Post
    washingtonpost.com
  3. News
    Hundreds Of People At 2 LA Universities Quarantined Because Of Measles Exposure -- NPR
    npr.org
  4. News
    Almost 300 People Quarantined at UCLA and Cal State LA Due to Measles Exposure -- Campus Security Today
    campussecuritytoday.com
  5. News
    Measles outbreak 2019: Hundreds of students quarantined at California universities -- CBS News
    cbsnews.com
Tags
measlesdisease-outbreakpublic-healthquarantinevaccinationcalifornialos-angeleshsihispanic-servinglibrarycontact-tracing
Added May 2026Updated May 2026Via ingestion