Every resident in San Francisco's Mission neighborhood offered test for coronavirus

Emiliano Garcia, 4 watches third year UCSF medical student Natalie Kucirek prick his mother's finger during an antibody test for COVID-19 during UCSF's mass testing study at Garfield Square. A comprehensive study of the virus's spread held by UC San Francisco researchers in partnership with San Francisco Department of Public Health and Zuckerberg General, mass testing is provided free of charge for the 5700 residents in a one mile square radius of the Mission district. less Emiliano Garcia, 4 watches third year UCSF medical student Natalie Kucirek prick his mother's finger during an antibody test for COVID-19 during UCSF's mass testing study at Garfield Square. A comprehensive ... more Photo: Mike Kai Chen Photo: Mike Kai Chen Image 1 of / 14 Caption Close Every resident in San Francisco's Mission neighborhood offered test for coronavirus 1 / 14 Back to Gallery

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UCSF launched an effort over the weekend to offer free, voluntary COVID-19 testing to every resident in a densely populated section of the Mission District, a neighborhood with among the highest number of coronavirus cases in San Francisco.

UCSF had tested 1,734 individuals in the neighborhood as of Monday morning and that number is growing.

The study is meant to reveal the invisible spread of the virus and help inform future testing efforts in other communities.

“All our public health decisions, including when it will be possible to relax regional and statewide shelter-in-place orders, are driven by rough assumptions about how this virus behaves based on very limited data,” said Dr. Bryan Greenhouse, an associate professor of medicine at UCSF, in a statement.

Greenhouse said studying the spread in detail will give researchers "crucial data points that we can extrapolate to better predict how to control the virus in similar communities nationwide.” UCSF is implementing a similar effort in Bolinas.

Day 2 of the Unidos en Salud study that is doing #COVID19 screening for Mission residents. So thankful for everyone putting in the hard work including @carina_marquez @UCSF_HIVIDGM @DHavlir @jessikator @AyeshaAppaMD the amazing community volunteers and the Latino Task Force pic.twitter.com/8gzSPMeIxF — Francesco D Sergi (@FrancescoDSergi) April 26, 2020

Testing began in the Mission District on April 25 and will continue through April 28. Testing at pop-up sites is available to approximately 5,200 residents in a 16-block area running from Cesar Chavez to 23rd Street and South Van Ness to Harrison Street (see a map in the gallery above). Find out if your address is eligible at unidosensalud.org.

Researchers are conducting two types of tests to identify those individuals who are currently infected and those who previously had the virus. The diagnostic tests for active COVID-19 are implemented by collecting samples with nasal swabs while the antibody test is done with a finger-prick to collect a blood sample. Results are available within 72 hours.

People who test positive will get immediate follow-up calls from UCSF infectious disease experts while those who test negative will be expected to continue to following the shelter-in-place order "because of the possibility of false negative test results and a general lack of information about the potential for reinfection with the disease," according to a statement from UCSF.

"The COVID-19 pandemic is disproportionately affecting the Latinx community in San Francisco, both in terms of infection rates and economic hardship, and we have been partnering very closely with the Latino Task Force for COVID-19 to support this community by working to disrupt transmission of the disease,” said Dr. Carina Marquez, an assistant professor of medicine at UCSF.

Study results are expected to be available as early as late May.

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Amy Graff is a digital editor with SFGATE. Email her: agraff@sfgate.com.