In short, yes, if that water has been infected by the feces of someone who has the disease. The reason why is because of the small size of the virus (less than 0.1-micron diameter), most cartridge-type filters will not remove them from water. A safe bet is to always either boil or adequately disinfect the water you take from a stream while camping, hiking, or biking in rural areas.
So what is Hepatitis A and what are its symptoms? Hepatitis A is a serious liver disease caused by a virus. Symptoms may include fatigue, poor appetite, fever, nausea, and abdominal discomfort. Urine may become dark and the whites of a person's eyes or their skin may become yellowed — a condition known as jaundice. Symptoms most commonly appear within three to four weeks after exposure, although symptoms can appear as early as two weeks and as late as six weeks after exposure. A person spread the virus as early as two weeks prior to showing any symptoms and will continue to spread the virus up to one week after the onset of jaundice. How exactly is the virus spread? The virus is ingested (swallowed), multiplies in the body, and is passed in the feces (bowel movements). The virus can be carried on an infected person's inadequately washed hands and be spread by direct contact or consuming food or drink handled by that person.
So how can Hepatitis A be prevented? The most effective way to prevent the disease is careful handwashing every time after using the toilet. You can greatly reduce your chances of getting Hepatitis A by carefully washing your hands after using the toilet. People working with ready-to-serve foods such as salads, fruits, and sandwiches or those who slice meats should wear disposable plastic gloves. They should be worn only for the task which they are provided and discarded when they become soiled, punctured or torn. If you feel ill, do not go to work. Tell your supervisor and see your doctor.
It is important to note that there is no vaccine to prevent Hepatitis A and no specific treatment once the person has the disease. Symptoms usually resolve with adequate rest and diet. Adults tend to develop more severe cases of the disease than children. People who have close personal contact with an infected individual or eat foods prepared by an infected individual should call their doctor or Health Department to obtain an immune globulin shot. This shot reduces the chances of becoming ill.
When hiking or camping you should always use your judgment and common sense before drinking from natural streams, as you have no way to accurately judge if the water is truly safe. The best rule of thumb is to bring bottled water along for hikes or camping if you are unable to boil water you safely collect.