All sorts of theories have been proposed to explain the rise — 6.4 million in 2011, a 42 percent jump from 2004 — in schoolchildren being told they have Attention-Deficit/Hyperactivity Disorder, or ADHD, requiring therapy, medicine or both.

Some believe it’s simply a matter of more awareness — meaning that more parents are seeking a diagnosis. Others blame the environment or diet. Now a new report from the Centers for Disease Control and Prevention brings up another possibility: improper diagnosis.

The CDC report takes an in-depth look at how children with ADHD came to get the label through a survey of 2,976 families. In 18 percent of cases, the diagnosis was done solely on the basis of family members’ reports, which is inconsistent with AAP recommendations that information be collected from individuals across multiple settings. Additionally, one out of every 10 children was diagnosed without the use of a behavior rating scale that is supposed to be administered.

Plague cases in U.S. are on the rise

There have been 13 cases and three deaths from plague in the United States in the past five months, but researchers do not know why the disease appears to be on the rise.

The number of U.S. plague cases usually averages about three a year. The Centers for Disease Control and Prevention reports that recent cases have afflicted residents of Arizona, California, Colorado, Georgia, New Mexico, Oregon and Utah. Two cases have been linked to exposure in or near Yosemite National Park.

While doctors say there is no need to panic, there are some practical precautions that outdoor adventurers should take. Plague is usually spread by bites from rodents and the fleas that feed on them. Dr. Christina Nelson, a medical epidemiologist with the CDC and an author of the report, said using insect repellents and wearing long pants were practical ways to prevent exposure. “If you do get a fever or lymph node swelling after being outdoors, make sure to see a health care provider and tell them where you’ve been,” she advised.

Pertussis passed on from siblings

A study has found that siblings, not mothers, are now the most common source of pertussis infection in newborns.

Infants can be given the DTaP vaccine (it also protects against tetanus and diphtheria) starting at 2 months, and the schedule calls for four more shots through ages 4 to 6.

Researchers determined the source of pertussis infection in 569 infants from 2006 to 2013. Fathers were the source of 10 percent of the infections, mothers of 20.6 percent, and siblings of 35.5 percent. Until 2008, mothers were the most common source of infection. The study was published in Pediatrics.

The finding is probably a result of waning immunity among children and adolescents who had received the DTaP vaccine. But vaccination of pregnant women remained the best strategy for preventing pertussis, said the lead author of the study, Tami H. Skoff, an epidemiologist with the Centers for Disease Control and Prevention, since the disease can spread from vaccinated siblings.

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