Organ donation saves many lives each year. Even though some transplanted organs are derived from living donors, the majority come from patients who die but still have healthy organs that can be of value to a transplant recipient. Potential organ donors can fill out an organ donation card to specify their wishes. If the donor is in critical condition and dying, the donor's family is usually consulted to discuss the donation process. Generally, the next of kin must approve before donation can occur, regardless of whether the patient has completed an organ donation card. In some cases, a family member overrides the donor's wishes. Do you think that family members should be able to overrule the stated intentions of the potential donor? Why or why not? Have you signed up to be an organ donor? Why or why not?

Pertussis (whooping cough) is caused by a bacterial infection, and symptoms include an intense cough that lasts for weeks, sometimes leading to pneumonia and death. A complete vaccination against pertussis requires five doses, completed by age 5. A pertussis outbreak occurred in California in 2010, and a news article reported the following: 'Among fully immunized kids, there were about 36 cases for every 10,000 children two to seven years old, compared to 245 out of every 10,000 kids aged eight to twelve.' Propose an explanation for these data and a public health solution based on your explanation.

Compare the outcomes of two different cases of infectious diseases in a community.

Case 1: A man with an infectious disease enters a community where the disease has not previously occurred.

Case 2: A man with an infectious disease enters a community where almost everyone has been vaccinated against the disease.