In a relatively brief timespan, the Kenyan writer and activist for LGBT rights Binyavanga Wainaina, who has died aged 48 following a stroke, made a revolutionary impact on literature from and about the African continent, promoting new writers and challenging entrenched stereotypes about identity and gender. He is perhaps best known for his scathingly satirical essay How to Write About Africa, which was published in Granta in 2005.

It became the magazine’s most widely read article, brilliantly sending up the cliches and reductionist views so often perpetrated by journalists or historians: “Never have a picture of a well-adjusted African on the cover of your book, or in it, unless that African has won the Nobel prize. An AK-47, prominent ribs, naked breasts: use these …

“In your text, treat Africa as if it were one country. It is hot and dusty with rolling grasslands and huge herds of animals and tall, thin people who are starving. Or it is hot and steamy with very short people who eat primates. Don’t get bogged down with precise descriptions. Africa is big: 54 countries, 900 million people who are too busy starving and dying and warring and emigrating to read your book.”

Less than a decade later, in a persistent climate of anti-gay legislation in Africa, Binyavanga marked his 43rd birthday by courageously outing himself as gay, acknowledging feelings he had had since childhood.

He had made a major entrance on the international literary stage in 2002 as winner of the Caine prize for African writing, worth £10,000. I was on the judging panel that gave the award to his story Discovering Home, which pipped to the post the entry from another young writer named Chimamanda Ngozi Adichie.

His prize money went towards founding in 2003 a Kenya-based literary magazine, Kwani? (meaning “so what?”), which would become one of the most influential platforms for writing from across the African continent, launching the literary careers of many, including Yvonne Adhiambo Owuor, who won the next Caine prize. Binyavanga was an enabler, whom the Kenya Publishers Association recognised with an award that year for his services to Kenyan literature.

Beyond Africa, his reach encompassed being, in 2007, writer-in-residence at Union College in Schenectady, New York, and in 2008, at Williams College, in Massachusetts. He also became director of the Chinua Achebe Centre for African Writers and Artists at Bard College, New York state. He completed an MPhil in creative writing at the University of East Anglia in 2010.

He wrote for outlets that included the East African, National Geographic, the Sunday Times (South Africa), Granta, the New York Times and Chimurenga magazine, as well as the Guardian. However, a projected novel never appeared.

His only book, the autobiographical One Day I Will Write About This Place, was published in 2011. In 2014, he framed a confessional essay entitled “I Am a Homosexual, Mum” as a lost chapter of that memoir, addressed to his mother who had died in 2000; his father, too, had died before Wainaina’s public announcement of his sexual orientation.

A follow-up tweet confirmed: “I am, for anybody confused or in doubt, a homosexual. Gay, and quite happy.” It was a brave and controversial stand for someone from a country that deemed same-sex relationships illegal.

Born into a middle-class family in Nakuru, Kenya, Binyavanga was the son of Rosemary, who ran a hair salon in the town, and Job, the managing director of an agricultural company. He attended Moi primary school in Nakuru, Mangu high school in Thika and Lenana school in Nairobi. In 1991 he went to South Africa, where he studied commerce at the University of Transkei (now Walter Sisulu University). He later freelanced as a food and travel writer, based in Cape Town, before returning home in 2000.

A unique way with words guaranteed that there was always a buzz to Binyavanga’s writing. He reminded us “what English can look like when it’s an African language”, said Ellah Wakatama Allfrey, Caine prize chair and former series editor for the 2013 Kwani? Manuscript Project (a one-off prize for unpublished African fiction).

When in 2014 Africa39 (for which I was a judge) was initiated by the Hay festival to identify 39 of the most promising writers under the age of 40, with the talent to define trends in the development of literature from Sub-Saharan Africa and the diaspora, the venture was heavily reliant on submissions researched by Binyavanga.

That was also the year he was named on Time magazine’s list of the world’s 100 most influential people. His citation was penned by Adichie.

Binyavanga’s appetite for life was a joy to witness, encompassing all things culinary, and he had a daringly unconventional dress sense that inspired warm smiles.

In 2015 he suffered a stroke. He subsequently wrote of being physically attacked in Berlin by a taxi driver impatient at the time it took him to search his phone for an address. Recent months had brought further ill health, and a second stroke.

On World Aids day in 2016 he revealed that he was HIV positive “and happy”, and in 2018 he announced that he was in love and would be marrying his long-term partner later this year.

His partner survives him, along with his brother, James, and sisters, June and Melissa.

• Kenneth Binyavanga Wainaina, writer and publisher, born 18 January 1971; died 21 May 2019