My son went to Cancun about 2 years ago. 2 weeks after he got home he ran a 103* fever, stiffness in neck, painful gums, waking up with bleeding gums, receding gums, a bitter taste in his mouth and extremely tired. It lasts 3-5 days then goes away. His gums totally heal. He was having every 2 weeks for the 1st year, he thought it went away but the symptoms just came back after about 1 1/2 years and it is very painful. Parasite?