A boy with measles circa 1963. It was his third day suffering from the rash. (Courtesy of the Centers for Disease Control and Prevention)

California, land of sun and surf, also is unfortunately having a terrible run of infectious disease. After a difficult flu season that resulted in more than 300 deaths of people under 65, the state is now grappling with a huge whooping cough epidemic, a large measles outbreak and, most recently, a localized outbreak of tuberculosis in Sacramento.

There appears to be no connection between the four public health threats, but that must be little solace to officials working to contain them. The most widespread is the outbreak of whooping cough (also known as pertussis), a bacterial infection that has spread to 4,558 people and killed three infants, according to this June 27 report in the San Jose Mercury News.

The disease is preventable via vaccine given to infants. Pregnant women can protect themselves and convey some immunity to their babies by getting immunized during the third trimester of pregnancy, according to the Centers for Disease Control and Prevention. The last epidemic in California was in 2010, and officials say the disease has a three- to five-year cycle. But a contributing factor is people who refuse to vaccinate themselves or their children.

That is also an issue in the state's measles outbreak, which, the CDC reported in May, had grown to include 60 people. State officials say 25 of them were unvaccinated, 19 by choice, and there were 18 more whose vaccination status was unknown. Measles was declared eradicated in the United States in 2000, but the CDC said in May that the outbreak had set a record nationwide for any year since then, with 288 cases. Public health officials admit they are alarmed and are urging U.S. residents to make sure they are immunized, especially if they are traveling to places such as the Philippines, where measles is widespread.

On Tuesday, health officials in Sacramento, California's capital, reported that four more students at a high school had tested positive for the active type of tuberculosis, bringing the total to five since a student tested positive in February. Authorities have screened about 500 people, turning up another four with active TB and about 120 with the latent type. Only one of the five students was contagious, said Olivia Kasirye, the Sacramento County public health officer.

Kasirye said that the four public health issues "are not connected" in any way and that "it is strange that they're all happening" within a short span. "California is a large state, and so you get a lot of things going on," she said in an interview.

Although the prevalence of tuberculosis is at historical lows in the United States, at about 10,000 cases annually, local outbreaks are not uncommon, said Lee Reichman, executive director of the Global Tuberculosis Institute at Rutgers University. It is much more common in other parts of the world, with about 8 million cases annually, he said.

The slow-growing bacteria are spread from person to person by aerosolized droplets emitted by coughing.

Reichman expressed worry about cutbacks in spending on public health in places such as California, though he knew of no link to the current outbreaks. "I think the message across all three diseases is that public health is a great secret until there's an outbreak," he said. "You pay for it, we keep people well, find disease" and contain it, he said. "Tuberculosis is an excellent canary in the mine."