statistics Archives – Skeptical Raptor

The Washington State Department of Health is reporting that as of August 4, 2012, the current whooping cough (Bordetella pertussis) epidemic has hit 3400 cases, over 15X more than the 214 cases reported at the same time last year. The epidemic has finally shown a big drop off in new reports this past week (pdf), although there are concerns that the numbers will increase against this fall as children return to school in the autumn.

Washington Pertussis 20120804 — Pertussis cases by week 2012 (red) vs 2011 (blue)

According to the Centers for Disease Control and Prevention, pertussis (whooping cough) can cause serious illness in infants, children and adults. The disease usually starts with cold-like symptoms and maybe a mild cough or fever. After 1 to 2 weeks, severe coughing can begin. Unlike the common cold, pertussis can become a series of coughing fits that continues for weeks. In infants, the cough can be minimal or not even there. Infants may have a symptom known as “apnea.” Apnea is a pause in the child’s breathing pattern. Pertussis is most dangerous for babies. More than half of infants younger than 1 year of age who get the disease must be hospitalized. Approximately 1-2% of infants who are hospitalized from pertussis will die. Continue reading “Whooping cough update: Washington state epidemic hits 3400 cases”

Ed Yong, a scientist and contributor to Discover Magazine, wrote an blog post, What does it mean to say that something causes 16% of cancers?, discussing a news report that stated that 16% of cancers around the world were caused by infections. Here are some excerpts:

A few days ago, news reports claimed that 16 per cent of cancers around the world were caused by infections. This isn’t an especially new or controversial statement, as there’s clear evidence that some viruses, bacteria and parasites can cause cancer (think HPV, which we now have a vaccine against). It’s not inaccurate either. The paper that triggered the reports did indeed conclude that “of the 12.7 million new cancer cases that occurred in 2008, the population attributable fraction (PAF) for infectious agents was 16·1%”.
But for me, the reports aggravated an old itch. I used to work at a cancer charity. We used to get frequent requests we got for such numbers (e.g. how many cancers are caused by tobacco?). However, whenever such reports actually came out, we got a lot confused questions and comments. The problem is that many (most?) people have no idea what it actually means to say that X% of cancers are caused by something, where those numbers come from, or how they should be used. Continue reading “Infections causes 16% of cancers–what?”