Tuesday, June 29, 2010

Did the anti-vaccine movement help create a whooping cough epidemic?

The nutters kill kids

A whooping cough epidemic has broken out in California, which is now facing what could be the largest outbreak of the contagious disease since 1958. Over 900 cases have been confirmed in the state—more than four times as many as last year—and 600 suspected cases are being investigated. The highly contagious disease can be deadly to infants—five have already died from the disease this year in California—but it’s eminently preventable through vaccination.

Officials are still investigating the causes of the outbreak, but some have already suggested that the anti-vaccine movement could be at least partly to blame. "California is the epicenter of vaccine refusal" in the United States, said Dr. Blaise Congeni from Ohio’s Akron Children's Hospital, according to an ABC News story. While California requires that children be vaccinated from whooping cough before they attend school, "the requirement is waived if parents file a 'personal belief exemption' (PBE), which need not be based on religion or medical necessity," the story continues. And some parents have been flocking to join the vaccine refusalists. ABC News cites Ken August, spokesman for the California Department of Public Health:
He said that the overall rate for PBEs among the state's roughly 7,200 schools is about 2 percent. But rates are much higher in some schools. Records for 2009 indicated that close to 175 schools had PBE rates of 20 percent or more. A few had rates above 70 percent.

Researchers have found that vaccination rates of at least 93 percent are needed to ensure so-called herd immunity against pertussis, which prevents the disease from spreading quickly to unvaccinated individuals.

Fears about vaccines are nothing new, but they’ve been revived in recent years by anti-vaccine crusaders who’ve junked science in favor of medical myths and conspiracy theories. In the US and abroad, they’ve popularized the notion that vaccines cause autism and that whooping cough is not actually fatal, among other falsehoods. There’s also the tireless conservative argument—promulgated by folks like the Eagle Forum’s Phyllis Schlafly—that government-required vaccines infringe upon individual liberty.

The claims by leading anti-vaccine activists have been thoroughly debunked. The US Court of Claims, for example, ruled last year that there was no substantive evidence to support the autism-vaccine link. The main researcher behind the claim, British doctor Andrew Wakefield, has been completely discredited and even stripped of his medical license.

But there's still reason to be concerned about the damage that the movement may have already done. Vaccine-phobia has gripped towns like Boulder, which in 2002 had the lowest school-wide vaccination rate in Colorado—and "one of the highest per capita rates of whooping cough in the United States.” And now children in California are dying of a disease that should have been made obsolete by the 21st century. If vaccine refusals are indeed behind the current epidemic, California needs to figure out the real reasons that parents are putting their own children and others at risk.*


Simple blood test will give women precise age at which they will no longer be fertile

Could be useful even if only approximately right

DOCTORS were set to unveil tomorrow a simple blood test that could tell young women the precise age at which they would no longer be able to have babies.

The test - which measures levels of a hormone produced by the ovaries - could allow women as young as 20 to pinpoint within a few months when they would cease to be fertile.

The procedure, to be launched in Rome at the annual conference of the European Society of Human Reproduction and Embryology, would be valuable to women trying to balance careers with having children.

Among Western women, menopause occurs on average at 51. However, about 15 per cent of women experience it early, under the age of 45.

“Our results suggest that the novel marker anti-Mullerian hormone (produced by the ovaries) could precisely forecast the age at menopause, even in young women,” said Dr Fahimeh Ramezani Tehrani, who led the research.

Dr Tehrani analysed levels of the hormone, which controls the development of the cells in the ovaries from which eggs develop, in 266 women aged 20 to 49.

It was known that levels of the hormone vary between women and also decline with age. Scientists previously suspected that changing levels were linked to menopause, but there was insufficient data to use this knowledge as a predictive tool.

By gathering data from a large number of women, Dr Tehrani believes she created a mathematical model that can predict the age of menopause for any woman.

The test developed by Dr Tehrani, a senior researcher at the World Health Organisation-backed Endocrine Research Centre in Tehran, would need to be validated in large-scale trials before it could come into common use.


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