David Tollner gets text messages telling him when meals are placed outside the door of the family guest room, where he was banished after developing a cough.

His wife Mitra Ahani is taking no chances as the coronavirus pandemic spreads in the United States -- even though she knows her husband may have no more than a common cold.

When Tollner returned to their home near Santa Cruz from a conference in Baltimore, she steered him directly to the shower, leaving doors open so he wouldn't touch them, and wiped down his suitcase with bleach.

When he started coughing, Tollner was relegated to a spare room.

"I locked him in the guest room," confirmed Ahani, a chief executive of a center that provides educational support for children with disabilities, who like millions in this tech-savvy region has shifted to remote work in response to the spreading coronavirus. 

"He probably caught a little cold out there. But it scared the daylights out of him, and he needed that."

In an interview with AFP, Tollner wryly acknowledged his predicament.

"I'm here in the dungeon waiting for food and water," he said Friday. "I have been here for a couple of days now trying not to infect the world with something I don't know I even have."

Tollner relies on his laptop and smartphone to run his law firm in the Silicon Valley city of San Jose.

Like tens of millions across the United States -- where school districts are closing one after the other and firms are massively encouraging telework -- the family is avoiding going out; relying for daily life on many of the technologies invented or refined in the area. 

Ahani orders most of what they need from an online grocery delivery service, wearing gloves and wiping down goods with sanitizer when they arrive.

Flexibility... and isolation 

Martha Lackritz-Peltier, an attorney at nonprofit group TechSoup, is working from her home in Oakland, where her companions include two dogs and hummingbirds flitting about the garden.

"Frankly, I kind of enjoy the flexibility of sometimes lying in bed with my laptop and working on my lap," she said. "I love being able to sit outside and get some sunlight."

Remote collaboration platform Slack has been speaking with companies of all sizes about tools and techniques for employees to work together in real-time while being physically apart.

"Isolation is one of the biggest threats to a team's engagement and motivation, and it can happen silently day by day," a company spokesperson told AFP.

"Maintaining camaraderie, encouragement, and collaboration can make all the difference in the weeks ahead."

Read also: Google building self-check website for coronavirus

Ghostly Googleplex 

Across Silicon Valley, streets have emptied as the pandemic takes hold, claiming more than 50 lives so far in the United States.

People were few and far between at the "Googleplex" in Mountain View midday on Thursday, a time when throngs typically stroll, sun or grab meals at the cornucopia of food trucks or cuisine stations on the tech giant's campus.

A Googler wearing eyeglasses with tiger-stripe frames stood alone in the shade of a tree near a daily "Block Party" lunchtime event for employees on campus.

"At least the block party was a lot better today -- there were no lines," he said.

At Facebook's closed campus in the nearby city of Menlo Park, valets stood idle in mostly empty parking lots usually crammed to overfilling.

Empty shuttle buses came and went from vacant stops. No one could be seen in the town-square style center courtyard at One Hacker Way, and birdsong was the only tweeting of note.

'Stir-crazy' 

Foot traffic was scarce in Palo Alto, a social hub for Silicon Valley as well as nearby Stanford University, which has suspended in-person classes.

"The street has been quieter, but we have been busy all day," ZombieRunner barista Zac Terrones told AFP while whipping up an oat milk latte.

"I think people working are getting stir-crazy at home and coming in for a little pop. I've washed my hands about 200 times today."

Stanford students Ende Shen and Yaqing Yang, both 21-year-old juniors from China, studied at a table on the sidewalk.

"We have communities on campus and some of them are kind of falling apart simply because of the health issues," said Shen, who is from a city near Shanghai.

Yang tries to stick to a routine, scheduling time to spend in the sunshine and study with peers such as Shen.

"I think it is really important to be in contact with the world despite bearing in mind social distancing," said Yang, who is from the capital of Sichuan province.

"I also cook a bit more now; it helps me stay sane and feel I have less need to go to crowded spaces."