did Bram Stoker write any continuation stories to dracula?

Answer 1

No he didn't, and, in fact the book was initially very poorly received. It sold less than 3000 copies.
But Fred Saberhagen has written (among others )some great Dracula novels:

Dracula sequence
Saberhagen's Dracula novels are based on the premise that vampires are morally equal to normal humans: they have the power to do good or evil, it is their choice. The first in the series "The Dracula Tape" is the story of Bram Stoker's "Dracula" told from Dracula's point of view. As the continuation of the series makes obvious, in this version, Dracula survives the best efforts of Harker, Van Helsing and company, who are portrayed largely as bungling fools. In later novels Dracula interacts with other literary characters including Sherlock Holmes and Merlin.
The Dracula Tape (1975)
The Holmes-Dracula File (1978)
An Old Friend of the Family (1979)
Thorn (1980)
Dominion (1982)
A Matter of Taste (1990)
A Question of Time (1992)
Seance for a Vampire (1994)
A Sharpness on the Neck (1996)
A Coldness in the Blood (2002)

By the way, "Dracula's Guest" (mentioned below)was excised from the original DRACULA MSS by his publisher because of the length of the original book MSS andwas published as a short story in 1914, two years after Stoker's death, can be read free on-line at the second link below.

Answer 2

Although Bram Stoker never wrote a continuation of Dracula, there is a portion of the original story that's never been included in any publication of the novel.

It's a sequence that takes place early in the novel, while Jonathan Harker is making his journey towards Dracula's castle--Harker has a foretaste of the horrific doings to come, and and has a timely rescue, due entirely to the foresight of his host-to-be. As creepy as it is, the sequence would have harmed the slowly-building mystery and suspense of Harker's journey, as well as lessened the effect of his first meeting with Count Dracula, so it was omitted before publication.

As published in short-story form, the sequence is titled "Dracula's Guest" and can be found in several horror-tale anthologies, as well as in collections of Stoker's other scare-stories.

Answer 3

Bram Stoker did not, but Elaine Bergstrom wrote a good one titled "Mina." She originally wrote it under the pseudonym Marie Kiraly.

Answer 4

No. There are however a lot of continuations of Dracula by different authors.

Answer 5

No, thank God. I don't care if it IS the defining piece of modern vampire literature (well, until Anne Rice came along...), I've taught it 3 times and it gets worse every single time. Ugh.