Letter cites coronavirus concerns, rampant mistreatment
Gathering was to have taken place in San Francisco Bay Area in July
Detainees with compromised immune systems at increased risk for coronavirus
Activists remain on lockdown as disease ravages countries
Group notes detainees at heightened risk of coronavirus
Tijuana LGBTQ migrant shelter scrambling to prepare for pandemic
Advisory notes coronavirus has prompted countries to close borders
Disease could be 'death threat' to anyone with compromised immune system
Companies cancelling cruises, hotels closing properties
Democrat cites coronavirus in statement