Saturday, February 04, 2006

Bird Flu, Whooping Cough Topics at Gay Leather Meeting

Copyright © 2006 by Mark Gabrish Conlan for Zenger’s Newsmagazine • All rights reserved

It might have seemed an incongruous topic for a Gay men’s Leather group, but “Papa” Tony Lindsey, founder of the San Diego League of Gentlemen, decided to make the group’s February 3 meeting a presentation on two major disease threats — and not AIDS or STD’s, either. Lindsey said he picked the topic to draw on the expertise of two club members, San Diego County health promotion specialist Everardo Aguilar and former American Red Cross and Centers for Disease Control (CDC) health educator Mitch Metzner. Metzner’s presentation was on the potential for a worldwide bird flu pandemic on the order of the 1918 killer influenza, which took the lives of up to 150 million people, while Aguilar spoke on a seemingly more prosaic but still real health threat: adult pertussis, commonly known as whooping cough.

Metzner began by distinguishing potentially lethal strains of influenza from the so-called “seasonal flu” we’re all used to. He also described flu as a disease that incubates in animals, especially wild birds and pigs, and said new strains of flu frequently transmit from birds through pigs to humans before evolving to a point where they can move from human to human without an animal being involved. “Ducks infect other ducks and give it to farm animials, like chickens or pigs, and then to humans,” Metzner explained. “Sometimes a flu strain goes straight from birds to humans.” That, he said, was what the 1918 flu did — and what scientists are currently worried bird flu will do, too, though he stressed that contrary to some of the scare stories in the media no human has yet caught bird flu directly from another human.

“Pigs are an important player in the exchange of human diseases,” Metzner said. “We have enough genetic material in common to be able to exchange skin and other parts [including the implantation of pig arteries in humans to replace badly clogged ones and thereby prevent heart disease]. An intelligent disease like the flu can exchange genetic material [between lethal and non-lethal strains], so the virus can adapt itself to spread easily from person to person like seasonal flu does.”

Metzner said the current strain of bird flu “first appeared in China in 1996, and in 1997 six people died. In 2003 there was a more widespread incidence. December [2005] and January [2006] have been very significant months. Turkey and Iraq both have cases in humans, and the disease there was recognized in humans before it was recognized in wild birds.” He said the disease spreads through the air or by touching contaminated surfaces, and the virus can transmit over distances of six feet and remain alive outside a host for up to two days.

According to Metzner, by examining tissue samples from three victims of the 1918 flu epidemic — including two from people who died in Alaska and whose bodies were frozen in ice, thereby preserving them — scientists determined that the bird flu virus of today is genetically similar to the one responsible for the 1918 pandemic. “Symptoms are similar to those of seasonal flu, but they don’t include runny noses and the other cold-like symptoms of seasonal flu and they can include diarrhea,” Metzner explained. “The incubation period is one to four days and a child can spread it six days before symptoms show or up to 21 days after. The people most at risk are 65 or older.”

What’s worrying many people in disease prevention, Metzner said, is whether or not people today would accept the kinds of sweeping public-health interventions that took place to stop the 1918 epidemic. These included closing schools, banning all indoor public gatherings, and forcing people to wear face masks whenever they went outside on pain of arrest if they didn’t. Metzner said that the level of trust in government was far higher in 1918 than it is today and therefore it was easier to enforce regulations like these. “The chaos surrounding Hurricane Katrina has made people in the government concerned that people won’t follow measures like closing all bars and public gatherings,” Metzner said.

He also pointed to globalization as a complicating factor; whereas most advanced countries used to produce their own medicine, today drug-making is farmed out all over the world. Tamiflu, the only drug so far proved effective against bird flu, is made in only one country — Switzerland — and the chemical components that go into it are made elsewhere and shipped there. A pandemic could get in the way of medicine production by wreaking havoc with the transportation system, and could also encourage countries to block exports of medicines in order to serve their own populations first — leaving non-producing countries like the U.S. without the drugs.

According to Metzner, governments are already spending a lot of money to develop bird flu vaccines to try to stop the epidemic before it starts — or at least slow it down and control it. The city of San Diego, cash-strapped as it is, has allocated $500 million to the San Diego Zoo to develop a response to bird flu, including draining all the ponds in the zoo and locking up their birds in indoor enclosures to keep them from contracting the disease themselves and spreading it to humans. But Metzner admitted that so far, human intervention has never stopped an incipient epidemic, and he said even ordinary seasonal flus are becoming harder to treat. He explained that last year only 10 percent of seasonal flu cases were resistant to the two most common antiviral drugs; this year it’s over 90 percent.

Metzner said a bird flu pandemic has the potential to be more deadly than the one in 1918 because “there are far more people now. Also, there are twice as many chickens and pigs in China as there were in 1918. Nobody alive today is immune to the 1918 strain and they’re making vaccines based on what they think the virus will be like.” One potentially bright spot, according to Metzner, is that the U.S. Centers for Disease Control and Prevention (CDC) has just announced a test for bird flu that will produce results in four hours instead of two weeks.

Aguilar’s presentation was focused mainly on challenging two myths about whooping cough: that it’s strictly a disease of children, and that the standard vaccines given to most U.S. children still protect them in adulthood. Based on original research by Dr. Mark Sawyer, medical director of the County of San Diego’s immunization program, and the program’s lead nurse, Sue Hunt, his presentation focused on what pertussis is and how it can be diagnosed and treated.

“Pertussis is a bacterial infection caused by Bordatella pertussis,” Aguilar explained. “It goes into your lungs and creates a poison, a toxin, that attaches to the cilia— the little hairs that dirt and other things out of your lungs — and paralyzes them. So you cough and can’t stop, and with babies and young children there’s a distinctive ‘whooping’ sound when they catch their breaths between coughs. Adults don’t normally get that sound, so it’s often not diagnosed accurately.” The infection is characterized by a chronic cough that can last up to three and one-half months — the “hundred-day cough,” it’s often called — and the symptoms can also include vomiting, choking and loss of sleep due to continual coughing.

According to Aguilar, there’s another reason why pertussis wasn’t considered a major health threat in adults; it’s only in the last few years that scientists have discovered the immunity to it from childhood vaccinations doesn’t last into adolescence and adulthood. “Pertussis is not a ‘childhood disease,’ and it can spread quickly through the community,” he explained. “It can affect teens, adults, families and senior citizens. It’s highly contagious and is airborne through the particles that come out of your mouth when you cough.”

Aguilar said that San Diego County’s pertussis case levels have increased rapidly, from about 75 in 1997 to a spike of 225 in 2002. After a dip the next two years, they leaped again to at least 369 in 2005 — “at least,” Aguilar explained, because the records for last year are incomplete and some new cases may still be discovered. While most of the cases are in babies under six months old — Aguilar said that was because they’re too young to have been vaccinated — 23 percent of the county’s most recent cases occurred in 10- to 14-year-olds and 20 percent in adults over 30.

“The good thing about pertussis is that it’s a bacterial infection and therefore antibiotics are useful,” Aguilar said. The front-line treatment is a 14-day course of erythromycin, and if that doesn’t work there are three other drugs used in sequence: azithromycin (five days), clarithromycin (seven days) and Septra or Bactrim (14 days). So far, Aguilar said, no cases of antibiotic-resistant pertussis have been recorded. He said a pertussis vaccine for adults was approved by the U.S. Food and Drug Administration (FDA) in late 2005, the so-called “Tdap” booster given along with tetanus and diphtheria vaccines, but people with compromised immune systems or chronic illnesses shouldn’t use it.