I had a part in starting a virus this week – a virtual, digital one, not the C-word one. With time on my hands, I was browsing Twitter on Tuesday night when I spotted a tweet from Samantha Kelly in Rosslare. With the handle @tweetinggoddess, and 53,000 followers, Samantha used her digital power to start a ripple:

So many people are self isolating at the moment. Many have underlying illnesses. So if that is you and you would like help with anything or you are feeling lonely please tweet to me and I will spread the word so you can connect with others in the same situation. #Selfisolation

Samantha’s tweet, or rather the thought behind it, caught me just as I had been reading about the theft of thousands of surgical masks from St Luke’s oncology hospital in Rathgar, in Dublin, and stories of litre bottles of pink hand sanitiser disappearing from the bottom of hospital patients’ beds.

The actor Chris O’Dowd, with his 780,000 followers, shared my tweet right away. That boost alone put the campaign into top gear

Instead of tut-tutting or retweeting the dark humour of Covid-19 memes, I tweeted that I would start the ball rolling and volunteer to pick up groceries or collect prescriptions in the north Co Dublin village of Rush. I simply added the word “Rush” to the end of the hashtag and asked others in the towns, villages and suburbs of Ireland to do the same.

OK, I’ll take a lead: If anyone in the Rush area of Dublin is alone, isolated and needs shopping or meds or anything else picked up, happy to do so. Will leave at your door. #selfisolationhelpRUSH Do it for your local community? RT please.

Within minutes the #selfisolationhelp hashtag began ticking over, and offers of help came through – from Helen A in Dublin 8 with an offer to help in Kilmainham; Tom H in Ballincollig, in Cork; Maria O’D in Limerick; Bríd C in Roscommon.

Suggestions began coming in on how to get the message out to vulnerable people not on social media. To give it an extra boost I sent my tweet to some media contacts who have huge numbers of followers.

The actor Chris O’Dowd (@BigBoyler, with 780,000 followers) shared it right away and replied: “Lovely idea here for the possible weeks and months ahead.”

So many people are self isolating at the moment. Many have underlying illnesses. So if that is you and you would like help with anything or you are feeling lonely please tweet to me and I will spread the word so you can connect with others in the same situation. #Selfisolation — Samantha Kelly (@Tweetinggoddess) March 10, 2020

Lovely idea here for the possible weeks and months ahead. https://t.co/W5sjMTj59m — chris o'dowd (@BigBoyler) March 10, 2020

That boost alone put the campaign into top gear. This was Twitter at its finest: an instant crowd-source of motivated people working towards one goal: alleviating the worry of isolated strangers. There was barely a troll in sight. (They, of course, came later.)

By Wednesday morning the tributary of volunteering had turned into a roaring torrent of help, with offers from towns and villages across the country pinging up every second. BBC Radio Ulster and Newstalk had me on air to explain how this instant online movement was trying to match up offers of help with those who needed it.

The odd grinch suggested I was “virtue signalling” – making a big show on Twitter simply to garner more followers. There’s always one… or two.

Imagine a normal straw that you might get with a takeaway meal. Divide that straw into 10 tiny straws. Now try to breathe in and out through just one of those tiny straws

My motivation was this: four years ago I nearly died in a high-dependency-unit bed in an NHS hospital in central London. I’d developed, almost overnight, bilateral pneumonia: my lungs were giving up. The paramedic who came to my house was so concerned at scarcity of oxygen in my blood that he instructed the ambulance driver to put on “blues and twos” – lights and sirens – on the dash to the hospital.

If you want to know what it’s like to have a virus similar to Covid-19 that affects the lungs, start by imagining a normal straw that you might get with a takeaway meal. Divide that straw into 10 tiny straws. Now try to breathe in and out through just one of those tiny straws. That’s how hard it was to breathe. I thought I was dying. Luckily the pharmaceutical concoctions pumping through five cannulas into my hand stopped me from being intubated (made unconscious and having a tube inserted down my throat to do my breathing for me).

I wouldn’t wish this kind of condition on anyone. That’s my motivation behind the hashtag.

Many immunosuppressed people are worried about doing the basics of living at the moment: touching the door handles of shops, putting our Pin codes into ATM pads, even opening the doors of our cars. So the offers of help and support were to remove these worries from those of us now faced with a hermit-like existence for the next few weeks.

And it’s not just for those isolating because of the possibility of having the virus or fear of catching the virus but also to help those on the front line of combating Covid-19: the nurses, doctors, porters, cleaners, paramedics, canteen staff of our hospitals and clinics. Can you walk their dog? Pick up a package for them?

Signs are going up in shops, churches and post offices showing the hashtag #selfisolationhelp. If there isn’t a sign where you live, maybe you could do the same

One of the first people the hashtag helped was a woman on crutches in Portobello, in Dublin, who couldn’t get out of her house and needed an urgent delivery. With no family or neighbours available, she posted a request via the hashtag, and a woman nearby who’d volunteered the day before was put in touch with her. They’re now in contact. She had groceries delivered yesterday. The volunteer will now be keeping in touch.

I’ve made sure to tweet to volunteers to wash their hands, use disposable latex gloves for handling shopping bags and, critically, to keep their distance from those they are helping by leaving bags or parcels on a doorstep or at a gate. It’s also sensible for volunteers to tell a family member or friend who they are helping and give the address they are delivering to – there are always chancers out there, so the motto for all is to stay safe.

The hashtag has its own momentum now. It has replicated, spread and burrowed into many villages, townlands and hamlets. I dip in every couple of hours to retweet new offers of help in more areas of Ireland. My band of 16,000 followers do their own bit, by passing on new information to their followers in turn.

We need to do more. Signs are now going up in shops, churches and post offices showing the hashtag #selfisolationhelp and giving the phone number of a local volunteer. If there isn’t a sign where you live, maybe you could do the same. Some people are leaving their contact details with their local shops.

Neighbourhood groups were already setting up WhatsApp groups for their communities, with offers of fuel and food deliveries, even a reassuring phone call every day. With 15 days of isolation ahead of all of us now, the requests for help will increase. Join in if you can. One person in a village, five people in a town, 10 in a suburb can make a difference.

We’re in uncharted territory. New forms of social support are emerging. For all the downsides of social media, its trolls, its partisan yelling, sometimes, just sometimes, social-media platforms can deliver practical, necessary help. Sign up. Volunteer. Do even one good deed. Stay safe.