The writer made the revelation on December 1, World Aids Day, but he was hesitant to confirm his Twitter post to Nation.co.ke.
On Thursday, Binyavanga said he is living with the virus, and that he is “happy”.
“What I said (in a tweet) is true. I’m HIV positive and happy! That is all I can say,” he said.
“Look out for an essay I’m writing in January.”
The author won the prestigious Caine Prize for African Writing in 2002 and was in 2014 named by Time100 as one of the “Most Influential People in the World”.
The life of the 45-year-old founder of literary magazine Kwani?, who came out as a homosexual on January 14, 2014, has lately been full of controversy.
He stunned the world in April 2014 when he revealed that he had been a homosexual since he was five.
“I am five when I close my self into a vague happiness that asks for nothing much from anybody. Absent-minded. Sweet. I am grateful for all love. I give it more than I receive it, often,” he wrote on africasacountry.com blog.
“I can be selfish. I masturbate a lot, and never allow myself to crack and grow my heart. I touch no men. I read books. I love my dad so much, my heart is learning to stretch. I am a homosexual.”
In November last year, he appealed for help after suffering a stroke.
He was admitted to the Intensive Care Unit at Karen Hospital and was discharged three weeks later.
And in June, he claimed he had been viciously assaulted by a taxi driver in Berlin, Germany, as a crowd watched.
Binyavanga’s HIV revelation set Twitter alight, with some of his followers and readers praising his bravery as others took issue with it.
Many Kenyans are afraid of revealing their HIV status due to the stigma associated with it, and even more are afraid of finding out through voluntary testing and counselling.
“Proud of you. Hope the rest of the public can also come out spreading positive vibes like you do,” Linda Adongo said.
Mama Yao tweeted: “Way to go. Please scream it from the house tops. HIV is not a death sentence. Unless of course you let it.”
“You keep teaching by searingly living your truth,” Mumbi Kaptere told Binyavanga. “Thank you for your example and brave illumination of a different spectrum of being African”.
And Alan Kasujja wrote: “I've been thinking about this tweet. We've come a long way. HIV is almost demystified... pockets of stigma notwithstanding.”
But other commenters lashed out at the author, accusing him of making HIV look fashionable.
Calvin Dete said: “So being HIV positive is a new thing in town...is it a competition going by the number of accolades here...”
Paul Machira Kiruma agreed with Dete, hitting out: “Those encouraging you here r hypocrites, they, like me r wondering, WTF, will your dropping of bombs ever end?”
A literary critic commended the author’s courage but challenged him to help gays, one of the minority groups that has borne the brunt of HIV and Aids in Kenya, access medical care.
“[Binyavanga] is a brave man. Sadly, in the process, he fulfils so many stereotypes about gay men,” the critic told Nation.co.ke.
“But if he has the energy, he can sustain the struggle for gay men to have access to information and proper medical care. I doubt though, that [Binyavanga] has the energy for any long-haul campaign. Not physical energy: emotional energy and intellectual strength.”