State health officials are undertaking an investigation into Campylobacter infections, which is caused by drinking raw milk. So far four people have become ill.

All milk sold in grocery stores and any milk sold, by law, must be pasteurized. This process briefly heats up the milk to very high temperatures and kills almost all harmful bacteria, making it safe to drink and extend shelf life.

Campylobacter bacteria causes diarrhea, abdominal cramping, pain, nausea, vomiting and fever. The symptoms usually occur anywhere form two to five days from drinking the infected milk.

Children and those who have compromised immune systems can have the side effects become life threatening.

Interestingly, it is not permitted in Alaska to sell raw milk, but rather many people own "shares" of cows and people are allowed to receive their share of the cows' raw milk. In that case, testing or pasteurization of the milk is not required.

Alaska state officials said there have previous incidents "Outbreaks of Campylobacter are often associated with consumption of unpasteurized milk -- one such outbreak, traced to a Mat-Su Valley farm, resulted in 18 illnesses in Alaska in 2011."

The New York Times has previously reported about people in urban areas that prefer raw milk and use various grey market distribution channels to obtain it.

Raw milk does not have added fortified nutrients, such as Vitamin D and may result in children becoming vitamin D deficient.

The press release from Alaska health officials can be found here.