So, this is the SRD commentary on Lycanthropy cures:
"An afflicted character who eats a sprig of belladonna (also called wolfsbane) within 1 hour of a lycanthrope’s attack can attempt a DC 20 Fortitude save to shake off the affliction. If a healer administers the herb, use the character’s save bonus or the healer’s Heal modifier, whichever is higher. The character gets only one chance, no matter how much belladonna is consumed. The belladonna must be reasonably fresh (picked within the last week).
However, fresh or not, belladonna is toxic. The character must succeed on a DC 13 Fortitude save or take 1d6 points of Strength damage. One minute later, the character must succeed on a second DC 13 save or take an additional 2d6 points of Strength damage.
A remove disease or heal spell cast by a cleric of 12th level or higher also cures the affliction, provided the character receives the spell within three days of the lycanthrope’s attack.
The only other way to remove the affliction is to cast remove curse or break enchantment on the character during one of the three days of the full moon. After receiving the spell, the character must succeed on a DC 20 Will save to break the curse (the caster knows if the spell works). If the save fails, the process must be repeated.
Characters undergoing this cure are often kept bound or confined in cages until the cure takes effect.
Only afflicted lycanthropes can be cured of lycanthropy.
Society has several defensive mechanisms here, and it can be presumed that society has evolved to meet the threat. For example, it would be pretty much impossible that a town would not have a crop of belladonna growing, and many goodwives - taking advice of their mothers - would ensure a good crop is growing outside the kitchen. Note that if a healer administers the herb, you get to use the healer's heal bonus in place of the saving throw. With Skill Focus, it's not hard for a 3rd level expert to have at least a +11 bonus on heal checks, and depending on the rules you use +14 isn't remotely hard. That cures about half the afflicted population right then and there.
Beyond that, it's quite possible to introduce more refined methods here. For example, in my game the plant monkshood, (aconite, or wolf's bane) can be refined by moderately skilled alchemist into a potion which maximizes its effectiveness as a curative while minimizing its poisonous effects. Stored in an airtight vial, such curatives have a shelf life that is basically indefinite. Since alchemists in my game are only slightly less common than blacksmiths and brewers, any reasonably large community will have access to the services of an alchemist, apothecary, or witch capable of brewing such a cure.
So, assuming the first line of defenses fail, the next line of defenses is the village priest. Dealing with curses of this sort is part of the standard training of pretty much any man of religion. If the character knows he's afflicted, as most victims would, most will seek out a priest at the first opportunity for the safety of their loved ones at the least. Anyone bit by a potentially afflicted animal is going to want to go in for a 'detect curse' spell at the very least. Afflicted individuals that can't be immediately cured are comfortably imprisoned in chambers built for that purpose and the priest will prepare to try to exorcise the curse when it next manifests itself during a night of the full moon. Note that to this point, the victim is still in his right mind.
If the local village priest isn't sufficiently learned to handle the problem, he immediately sends by messenger to his parent church in the larger town (usually a days ride away) indicating the severity of the emergency. The parent church will either send an emergency response team - generally, a ranking priest, 1-4 Templars, 1-2 acolytes, and sometimes an inquisitor - to handle the emergency, or else will send a number of Templars and members of the civic guard (and a wagon) to fetch the prisoner for transfer to the main temple. In the event of a very remote area without a lot of priestly skill, this process can repeat a couple of times until you hit whatever regional capital has sufficient facilities to handle the problem. If this is a very large and cosmopolitan city, it might even be possible that a 12th level priest is available. In short, seeing the severity of the threat, the locals will muster every resource to meet it. And seeing that this won't have been the first time ever that lycanthropes have been encountered, they'll have a very sophisticated, knowledgeable, and appropriate response. This all follows from the fact that lycanthropes haven't taken over the world.
The priest in question will then bless the afflicted character cast guidance and make every possible effort to bolster the will of the victim, before casting 'remove curse' (from a safe position outside the cell). Ideally, the cell will have been constructed with this in mind and have various enchantments in place, often cast decades or centuries ago, that aid in this process. Of course, by this point unless the person is quite strong willed, it will be difficult to remove the curse. Ideally, the process can be attempted again over the course of several months, but if the curse takes hold, the difficult decision must be made to judicially executed the person in question. Generally they'll receiving counseling, the equivalent of last rites, and be given the robes of a penitent petitioner, allowed to say last goodbyes when appropriate and then executed privately by whatever method is expedient.
Of course, a few rebellious souls try to avoid clerical intervention to avoid this possible fate, and the bulk of new lycanthropes start in this fashion. However, of course the entire community has reason to fear and be suspicious of any such evasive behavior, so your best hope of getting away with that is to flee into the wilderness. And note that before you get that desperate, most people are going to try the poison, which tends to leave them incapacitated even if it doesn't work. It's not overly hard for society to catch these dangerous miscreants in most cases.
Beyond that, the city watch will certainly be trained to recognize the signs and work of lycanthropes, and will certainly be equipped to deal with such threats in even the smallest of towns. Twenty to forty men armed with crossbows and silver tipped bolts make short work of most young lycanthropes, and many members of the city watch will be skilled with nets or man catchers, will have blood hounds for tracking (and may be skilled at tracking themselves) and wealthier communities will have horses. A young lycanthrope generally goes down hard to a typical band of the guard lead or supported by town leaders of various sorts.
Beyond that, several major religions maintain militant religious orders dedicated to ridding the world of such curses as lycanthropy. An outbreak or report of such an incident will reach them within a week or two, and will generally be followed up on by an inquisitor (rogue/ranger of level 4-7), or paladin (level 3-6), a priest (level 3-5), an adept (cleric level 1-2), and 4-6 Templars (fanatic/fighters level 1-2) well equipped to meet such a threat. Often multiple such parties will converge on any reported incident.
Beyond that, while the national military prefers to leave hunting monsters to small well equipped parties, a serious scourge will probably call down a purge on an area where they just simply kill everyone in the region and leave it for the gods to sort out.
Taking all this together then, you have to look at this from the perspective of the lycanthropes. A young untrained lycanthrope is a serious danger to the entire community. A young untrained lycanthrope - say a 1st level commoner - lacks the skills to hide his affliction, lacks control over his shape to take advantage of his higher CR and so is basically helpless except on nights of the full moon, and may in fact betray the community at the first opportunity if he did not willingly join the band. The larger the band, the more likely they are to attract seriously threatening attention, and the more likely they are to - while mindless raging during the full moon - do things that betray their presence to their enemies. As such, it's not in the interest of a band of lycanthropes to start spreading their curse willy nilly the way a young and mindless lycanthrope might if left to themselves. They don't tend to leave survivors if they can at all help it. And if they do leave a survivor, it's in their interest to hunt him down and kill or capture him before he does something to give them all away. If the trail is cold, they'll leave him to his likely fate and the hands of the priests and count themselves lucky. Other they'd much rather keep such a person locked up on their own for a few months, and then keep them out of the way for a few years until the new lycanthrope has grown in power and control of his abilities. Only really in wilderness areas can they be truly free to rampage about, and in those situations lycanthropy just doesn't spread for lack of regular victims. Most cells of lycanthropes survive by being cunning and secretive, being very careful about expanding their cell and recruiting new members for the 'honor' of being a lycanthrope. Often they prefer to keep the honor within family lines, and are at least as zealous at caging up their younger members and preparing for a full moon as the communities would be if they knew about them. Hunting trips to remote regions just before the full moon are also solid plans to avoid leaving the tell tale evidence of a werewolf attack. Those that go about rampaging in a community quickly get discovered and winnowed out.
If your PC's contract lycanthropy, it's reasonable to assume that as average inhabitants of their world, they'll know at least as much and probably more about the scourge than your players do. As such, they'll certainly know about the protocols of reporting suspicious injuries to the authorities, and the basic remedies. A sprig of belladonna administered by a 3rd level expert apothecary gives probably better than a 50% chance of a full recovery right off the bat, just by RAW and without heavy optimization of the NPC.
In general I would agree with you that lycanthropes are not appropriate encounters for low level parties, and it would be a nasty trick to send a party of 1st level characters up against a lair of wererats. Depending on the level demographics of your campaign world, you might also want to lower the level of cleric that can cure the curse with a remove curse within the first 3 days. On my campaign world, 12th level clerics are extremely far from common, and that number just doesn't represent a realistic number in a world where characters about 10th level are numerable.
