Background to my story: This would be set on another, Earth-like planet thousands of years from the current time. Technology ranges from late-medieval period things to mid 19th century depending upon what country and city you're in, or if you're out in the middle of nowhere.
Thanks to a virus native to this planet, there are denizens that need to drink blood. It doesn't matter if it's oxygenated or not or whether it comes from a vein, artery, or capillary, so long as the individual in question receives enough when they need it. These afflicted people are considered living creatures, have a pulse, and breathe. Blood is used to help produce a byproduct of the virus that ensures longevity in the infected person.
Fangs are more of a body modification for status than something that sees actual use--teeth are filed and otherwise altered to resemble fangs, but when these people feed, most use small, very sharp knives intended to make small slices and neat, shallow punctures when done properly. People who have had this condition longer show and tell people who are new to it where it's safe to feed from and while they do raise livestock to feed from (both for blood and food), human blood is generally more helpful to them.
The amount of blood needed can vary anywhere from a few drops to about a pint depending on how long it's been since the person last fed and their overall condition (if they're sick from something, weaker than average, older). In larger cities and in areas where these people are accepted as part of the community, there would probably be transfusion devices to take blood from people to give to them. In areas where technology isn't as prolific, the person in question taking the blood would need to probably have a primitive suction device to take larger amounts of blood, since feeding via the mouth can be messy and somewhat wasteful. Blood is preferred ingested over put directly into a vein (worry not, these people also eat and drink like normal people, so blood isn't their main nutritional source), but they can take it via IV if totally necessary. Since the process to make more virus byproduct begins in the mouth and digestive tract and then goes out into the body where it mixes with another biochemical to make new byproduct, intravenous blood would get one component to make more byproduct but not the other, making it so the person would need to eat so the other component to making the byproduct could be produced and used by the body. Even so, getting the blood via IV and then eating would be less effective than just drinking the blood in the first place.
My questions are, what would someone without a lot of technology make a suction device out of and how effective would it be? Generally, the materials available would be wood, stone or glass and while the cities have something resembling plastic, it would be available in limited amounts to someone out in the countryside.
Also, where would be a safe place to feed from on the human body? I read some things in this thread: http://community.livejournal.com/little_details/1697217.html which suggested the brachial artery in the wrist, another main blood source in the elbow (name for the vein/artery not given there that I saw), or, for smaller amounts of blood, the fingers. The femoral, carotid and jugular areas weren't recommended because the person would bleed out rapidly and while there is a way in this setting for people to be rapidly healed from wounds, I don't think it would be in time to save the person being fed from if the bleeding is very rapid, even with pressure applied to the area. In most cases, the goal isn't to kill the person being fed from, so feeding is consensual.
Also, how long does it generally take blood to clot/oxidize? I'd think there would be something available in this setting to delay that process for a few hours so blood could be transported short distances for those that can't hunt for themselves.
I used Wiki and Google and while I found some decent anatomy illustrations, I wasn't told much about how transfusion devices worked, what early ones were made of, or much about vampiric feeding in general. I'd really appreciate some help here, though please keep in mind I'm not a medical person and won't understand a lot of medical terms unless they're broken down or supplemented with layman's terms.
Thanks again for all the help!
Edit: I'm considering the infected people using leeches as containers and the infected people alternating between them before the leeches can fully digest the blood, and glass containers. However, if I go with the 'glass container and anti-coagulant' method, I'd need a way to create suction between the wounded person's wound and the glass so the blood could be drawn in. Not everyone would have access to needles, especially outside heavily inhabited areas.
I'm also looking into blood storage methods that predated freezing them, but haven't been able to find much. What were they? How effective were they? How suitable was blood for use after it was stored with some of these methods? I know that these days when blood is frozen it's more complicated than sticking it into a freezer then thawing it back out later.
Also, how safe is it to feed from the brachial artery? How fast would bleeding out occur and how fast could it be controlled? Thanks again!