I know the most common origin for werewolves is a bite by another werewolf. But a curse can be a acceptable origin for a transformation and, less often, we can see that sleeping under the full moon can transform someone into a werewolf.
But do other origins exist? Anything else, even if it doesn't involve a 'classic' transformation.
One possibility is to be the seventh son of a seventh son. This is listed on wikipedia as a superstition in the UK. In Paraguay, Argentina and Uruguay, it is only required to be a seventh son. I recall this legend from childhood when I used to read books about the supernatural.
The wikipedia article on werewolves has a section on becoming a werewolf. Some that you did not already list include:
It really depends on the type. Many cultures have different myths about how to become one. Common ones are being bitten, being born, and drinking rainwater from the footprint of a werewolf or drinking downstream from one. There are multiple origins of them. In Greece a king named Lycaon attempted to feed Zeus human flesh at a banquet and was turned into one along with his sons. They became the humanoid werewolves with a human posture, a wolf like head and hair/fur covering their body.
Another story is Native American in which a spirt, or something similar, took the form of a traveler. He came across two brothers and asked them for some food from their latest kill. Later he came across them again when they were unable to find food. He gave them the ability to turn into wolves at will because if their kindness. They were not allowed to use this to harm others. One brother became angry one day and killed a fellow tribe member. He was cursed to turn into a wolf at night. This may be where the full moon curse comes from.
A story of a modern day werewolf is the beast of gevaudan where a large doglike creature terrorized France for many years and mainly targeted women and children instead of livestock. It was said that is was killed by a silver bullet. For a better explanation google the story. This didn't exactly answer your question but it answers many werewolf myths. Best answer would be bite born or having the ability to shapeshifter
For Native Americans, werewolves were known as Skinwalkers, a man imbued with the spirit of an animal. Neither a curse or an affliction, these beings were considered almost shamanistic in nature, and were quite revered. Though generally they turned to true form (as the animal, not as a hybrid man/thing), skinwalkers were born this way, and their children were as well. It could be granted by the spirit (generally, fox, cayote, stag, and wolf were the well known ones) for those who were exceptional; a great hunter, a clever man, one with nature, etc. Supposedly, this also alters their way of thinking to that of the animal. They also can change at will, as oppose to the waxing and waning of the moon.
The Fae, the race of faeries of Druidic lore, were Shapechangers, and could alter their appearance at will. I think this was more magical than physical transformation, but many were known to adopt disguises. Robyn Goodfellow-called-Puck, of Shakespere's Midsummer's Night Dream, turned into an animal, but was still his good old mischievious self.
Changelings are a seperate humanoid race that could theoretically look like anyone/anything, within reason. They could look like a person or an animal (but not a plant). This is more common in Germania, and I believe in Scandinavia as well. Today, the concept of the changeling is now the children's myth, the Boogeyman, a creature that haunts a small, dark place that kidnaps children by preying on their fears.
As for actual Lycanthropy, werewolves were more popular in the European continent, though there are lore in other lands for something similar. Their existance and creation are as numerous as the cultures and nations of our world. Stepping over a grave unknowingly in Armenia might change you into a vampire, so who knows what they might think might make a wolfman? I've heard of a man surviving execution (Russia), a spirit of vengence (some of those cute countries that use to be a part of Russia), a survivor of a wolf attack (Germania/Central Europe), and my favorite, an offender of God (Italy). In the Orient, anything considered a shapechanger was a spirt/possessor. Haven't heard much on African lore or South American lore. If I remember correctly, an Aborigine Werewolf was a predator that could stand up on its own two legs; a reverse-werewolf in a sense.
This probably isn't the best answer to your question, but I wanted to hit upon some of the diversity of what we think of as werewolves.
The condition of werewolf-ness, or "lycanthropy", was first described as a form of punishment for the afflicted individual's actions. There is an excellent description of the history of lycanthropy on the Wikipedia page for "werewolf".
The earliest stories about werewolves come from Late Antiquity, and typically explained the condition as a punishment from the gods for some heinous crime, such as murder, cannibalism, or impiety.
From the wiki page:
In the second century BC, the Greek geographer Pausanias relates the story of Lycaon, who was transformed into a wolf because he had ritually murdered a child. In accounts by the Bibliotheca (3.8.1) and Ovid (Metamorphoses I.219-239), Lycaon serves human flesh to Zeus, wanting to know if he is really a god. Lycaon's transformation, therefore, is punishment for a crime, considered variously as murder, cannibalism, and impiety. Ovid also relates stories of men who roamed the woods of Arcadia in the form of wolves.
And:
The curse of lycanthropy was also considered by some scholars as being a divine punishment. Werewolf literature shows many examples of God or saints allegedly cursing those who invoked their wrath with werewolfism. Such is the case of Lycaon, who was turned into a wolf by Zeus as punishment for slaughtering one of his own sons and serving his remains to the gods as a dinner. Those who were excommunicated by the Roman Catholic Church were also said to become werewolves.
And:
According to Armenian lore, there are women who, in consequence of deadly sins, are condemned to spend seven years in wolf form. In a typical account, a condemned woman is visited by a wolfskin-toting spirit, who orders her to wear the skin, which causes her to acquire frightful cravings for human flesh soon after. With her better nature overcome, the she-wolf devours each of her own children, then her relatives' children in order of relationship, and finally the children of strangers. She wanders only at night, with doors and locks springing open at her approach. When morning arrives, she reverts to human form and removes her wolfskin. The transformation is generally said to be involuntary, but there are alternate versions involving voluntary metamorphosis, where the women can transform at will.
And:
In Hungarian folklore, the werewolves used to live specially in the region of Transdanubia1, and it was thought that the ability to change into a wolf was obtained in the infant age, after the suffering of abuse by the parents or by a curse. At the age of seven the boy or the girl leaves the house and goes hunting by night and can change to person or wolf whenever he wants. The curse can also be obtained when in the adulthood the person passed three times through an arch made of a Birch with the help of a wild rose's spine.
So in the earliest tales of werewolves, one became a werewolf because of some evil deeds one had performed in the past. The concept of lycanthropy being the result of a kind of "infection" transmitted by a bite is a relatively recent invention.
1 User14111 informs me that Transdanubia is Western Hungary, Dunántúl in Hungarian - the area west of the Danube River.
