Epidemiology Unit—2019 Novel Coronavirus

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The World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and state and local jurisdictions across the nation are closely monitoring an outbreak of respiratory illness caused by a novel (new) coronavirus (COVID-19). It was first detected, in December 2019, in Wuhan City, Hubei Province, China and continues to expand. Chinese health officials have reported thousands of infections with COVID-19 in China, including outside of Hubei Province. A number of countries, including the United States, are actively screening incoming travelers from Wuhan. Human infections with COVID-19 have been confirmed in Taiwan, Thailand, Japan, and South Korea. The United States announced its first case detected in a traveler returning from Wuhan to Washington state on January 21, 2020.

Coronavirus Disease 2019 (COVID-19) in San Diego County

The County of San Diego is working closely with our federal and state partners to monitor an outbreak of respiratory illness caused by a novel coronavirus (COVID-19).  These tables will be updated regularly.

Patients Under Investigation (PUIs) in San Diego County

2019 Novel Coronavirus (COVID-19)

Updated February 28, 2020

  San Diego County1 Federal Quarantine2 Non-San Diego County Residents3
Positive (confirmed cases) 0 2 0
Pending Results 5 0 1
Negative 13 11 1
Total Tested 18 13 2

1This includes Customs and Border Protection (CBP) and Immigration Customs Enforcement (ICE) local detainees.

2Individuals on repatriation flights (2/5/20 and 2/7/20) from Wuhan, China under federal quarantine at Marine Corps Air Station (MCAS) Miramar.

3Non-residents include out-of-country visitors.

Number of People Under Public Health Supervision4

in San Diego County

Updated February 28, 2020

Persons monitored (cumulative) 390
Persons actively being monitored 141
Persons who completed their monitoring 249
4The number of people under public health supervision includes those at risk of having been exposed to novel coronavirus who are monitoring their health under the supervision of public health officials. This number includes close contacts of laboratory confirmed cases, as well as people who have returned from China in the past 14 days.


What is 2019 novel coronavirus (COVID-19)?

Coronaviruses are a large family of viruses that are common in many different species of animals, including camels, cattle, cats, and bats. 

Since December 2019, Chinese authorities have identified thousands of human infections, including several dozen deaths, associated with this novel (new) coronavirus in an outbreak of pneumonia in Wuhan City, Hubei Province, China. In addition, novel coronavirus infections have been confirmed in numerous international travelers in multiple countries, including the Untied States, who traveled to or came from Wuhan City. 


How is 2019 novel coronavirus (COVID-19) acquired or transmitted?

Rarely, animal coronaviruses can infect people and then spread between people such as with Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS). Many of the patients in the pneumonia outbreak caused by COVID-19 in Wuhan, China had some link to a large seafood and live animal market, suggesting animal-to-person spread. However, a growing number of patients diagnosed with COVID-19 have not reported exposure to animal markets, indicating person-to-person spread is occurring.

When person-to-person spread occurred with MERS and SARS, it is thought to have happened via respiratory droplets produced when an infected person coughed or sneezed, similar to how influenza and other respiratory illnesses spread. The spreading of SARS and MERS between people generally occurred in people who had close contacts with others who were infected.

How easily a virus spreads from person-to-person can vary. Some viruses are highly contagious (like measles), while other viruses do not spread as easily. It is not yet clear how easily COVID-19 spreads from person-to-person. It is important to know this in order to better understand the risk associated with this virus.

Investigations are ongoing about the transmissibility, severity, and other features associated with COVID-19. The latest situation summary updates are available on CDC’s web page 2019 Novel Coronavirus, Wuhan, China.


What are the symptoms of 2019 novel coronavirus (COVID-19)?

Patients with confirmed COVID-19 infection have reported mild to severe respiratory illness with symptoms of:

  • fever
  • cough
  • shortness of breath/difficulty breathing

At this time, the CDC believes that symptoms of COVID-19 may appear in as few as 2 days or as long as 14 days after exposure.


How can you protect yourself?

Practice everyday preventive actions to help prevent the spread of respiratory viruses, including:

  • Wash your hands often with soap and water for at least 20 seconds. If soap and water are not available, use an alcohol-based hand sanitizer.
  • Avoid touching your eyes, nose, and mouth with unwashed hands.
  • Avoid close contact with people who are sick.
  • Stay home when you are sick.
  • Cover your cough or sneeze with a tissue, then throw the tissue in the trash.
  • Clean and disinfect frequently touched objects and surfaces.

These everyday habits can help prevent the spread of several viruses.

People who think they may have been exposed to COVID-19 should contact their health care provider immediately.

*If you are traveling, read the CDC recommentions on What travelers can do to protect themselves and others.


Suspected cases of COVID-19 should be reported by telephone to the San Diego County Epidemiology Unit immediately at (619) 692-8499 during business hours or at (858)-565-5255 after hours, on weekends, or holidays.

County of San Diego

California Department of Public Health

Centers for Disease Control and Prevention

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For more general information about the Novel Coronavirus, please call 2-1-1 or visit www.211sandiego.org 

For other health and medical information, contact the Epidemiology Unit at (619) 692-8499 or send us an e-mail.