Argentina Travel Health and Security
Argentina poses no serious health risks for the traveler, but malaria and other tropical diseases do exist in the north near the Bolivian border. If you plan to travel extensively in this area, consider malaria medication and certainly do your best to avoid insect bites by using repellant, covering up, and sleeping under a mosquito net if necessary.
As for the rest of the country, make sure your standard immunizations are up to date (tetanus-10 yrs, polio-10 yrs, typhoid-3 yrs, hepatitis A) and you'll likely experience nothing worse than a bit of traveler's diarrhea. Get your shots early, at least a month before you go. Diarrhea that gets worse instead of better after a day or two is a more serious condition and often requires treatment; consult a physician in this case. Tap water is generally safe to drink, and certainly is in Buenos Aires--but be more careful in the rural north, where you might well stick to bottled water.
Medical facilities tend to be good and inexpensive, but trust your instincts if a hospital isn't up to your standards of hygiene. See emergency contacts for a list of hospitals in Buenos Aires, or contact your embassy for their preferred list. Travel insurance, covering medical expenses as well as lost property, is recommended.
Here are some great web resources on travel health:
Security and Safety
Although crime is up since the economic collapse, and there has a been a wave of much publicized kidnappings, Argentina remains one of the safest countries in Latin America. That being said, keep vigilant in the big cities to minimize your chances of a trip-spoiling misfortune. Taxis with Radio Taxi and an IRA logos (no, not the terrorist organization) are regarded as the safest, or better yet take a remis (call-taxi), especially when you have your luggage in tow. Hotels and restaurants can arrange for remis pickups.
Be especially careful after withdrawing money from ATM machines. Try to use small or exact change when paying taxi drivers, and watch out for bill-swapping shenanigans. Other common scams include spilling something nasty on you on a busy street, then picking your pocket in the ensuing confusion. Bag snatchings are common, so hold on tight to your handbag or backpack. Better yet, don't bring one along.