Valeria Luiselli’s “singular, teeming, extraordinary” novel Lost Children Archive has won the £30,000 Rathbones Folio prize. The Mexican-born novelist and essayist is the first woman to win the prize since its inception in 2013.

The planned ceremony at the British Library in London was cancelled because of the coronavirus pandemic, but the chair of judges, Paul Farley, called on those watching the event online to imagine the award ceremony: “a podium, flutes of house prosecco, the din of assembled guests and the speeches”. Organisers of the prize broadcast the presentation live on Twitter and its website.

Farley, an award-winning poet, spoke from Lancashire and Luiselli was in New York for the event. In a recorded speech, Farley said there was “still a cause for celebration”, and he described Lost Children Archive as a “genuinely original and bravura performance of a novel: a road trip, a documentary, a portrait of a family and of the American borderlands, and a journey into the idea of home and belonging”.

Photograph: FMcM Associates/PA

Luiselli, who lives in New York, was inspired to write Lost Children Archive by her work with young migrants on the Mexico-US border. The autobiographical novel, her third and her first to be written in English, brings together a family road trip from New York to the southern border with stories of Mexican children trying to cross into the US. Longlisted for the Booker last year, it beat titles including Zadie Smith’s first short story collection, Grand Union, and Forward prize-winner Fiona Benson’s poetry collection Vertigo & Ghost to win the Folio award, which is open to books of all genres.

Luiselli was “happy, sad, confused and overwhelmed” on learning she’d won the prize.

“First I was smiling, and then my publisher in London said, ‘How I wish you were coming so we could toast and be together,’ and I started crying,” she said, speaking on the phone from New York. “Writing is a solitary work, so to celebrate with the team you worked with doesn’t happen so often. That was frustrating and sad but everyone in the world is feeling that same frustration, at the fact we cannot come together the way we’d like to.”

The writer said she was “deeply thankful that we can continue, that we can say, ‘OK, we can still give a literary prize, and you know why? Because we believe in books as the echo of something so much greater than us, and much greater than this moment.”

Farley said that he and his fellow judges, the novelists Nikita Lalwani and Ross Raisin, were unanimous in their choice of Luiselli, with their gatherings over the winter “to talk about nothing but books for a few hours over a drink already … like idylls from a bygone age”. Their final meeting to decide the winner “took place online, without so much as an elbow bump”.

“Last year, when I was invited to be chair of the Rathbones Folio prize, my first duty was to offer a few words for a press release. I heard myself saying something about how judging through the autumn and winter would lead to an emerging, sometime around the spring equinox, into the lengthening daylight with a winner,” Farley said in his speech. “Things haven’t quite worked out like that … the room in the British Library where the Rathbones Folio prizewinner for 2020 would have been announced this evening is currently dark, along with theatres, galleries, cinemas and stadiums everywhere.”

But he reminded those watching that there was “still a cause for celebration”, and that “as daily life suddenly feels circumscribed and uncertain … I also think of how a novel, story or poem, now more than ever, can reassert its ability to transport and illuminate”.

Rathbones Folio prize director Minna Fry said that it had been “quite a challenge to keep up” with changing realities, but the prize’s organisers were “determined to find a way to go ahead, to celebrate the eight brilliant shortlisted authors and to reward the book our judges considered the very best of the year”.

Previous winners of the prize, which was set up after the Booker prize was accused of prioritising readability over artistic achievement, include Raymond Antrobus, Hisham Matar and George Saunders.