Meningitis

Lacey Hamlyn considers herself lucky—which is surprising, since the 17-year-old almost died from invasive meningococcal disease (IMD). Why? Because she survived when many victims don’t and suffered no permanent physical damage when many victims do. “I thought it was a migraine, but it was the sensitivity to light,” she says, describing two telltale signs of IMD—severe headache and photosensitivity. So bad were both, says her mother Elaine, that even a cloth over her eyes in a dark room wouldn’t lessen the pain. Like many parents, Elaine Hamlyn was not unaware of the dangers of IMD—or meningitis, as most people call it—which mostly targets children, teens and young adults. The deadly bacterial infection comes on virulently and often kills within hours of symptoms appearing. By the time Lacey was rushed to the hospital it was anybody’s guess if she would survive.

For travellers, IMD represents a grey zone of risk. Statistically, travellers are at low risk for it and it’s not considered highly contagious by public health experts. In 2005, only 181 cases were reported in Canada, likely because many people have a natural immunity that stabilizes the overall incidence. Yet it’s worth noting that IMD is a human disease—we are the reservoir of the bacteria, which can reside in the throats and noses of up to 25 percent of the population. (Many people are asymptomatic carriers who never get sick, but transmit the microbes in droplets when they sneeze or cough.) IMD is endemic to all countries and is epidemic in parts of the developing world where thousands of cases appear annually. The most notorious region is the “meningitis belt” of sub-Saharan Africa, which runs from Senegal in the west to Ethiopia in the east, where IMD is a threat during the continent’s entire dry season(from December to June). In the first six weeks of 2008, the belt recorded more than 2,300 cases and 324 deaths. That’s compared to the devastating epidemic of 1996—which saw 250,000 cases and 25,000 deaths (and likely many more unreported). The two most serious forms of IMD are meningococcal meningitis, a swelling of the membranes lining the brain and spinal cord, and meningococcal septicemia (meningococcemia), a deadly blood-borne infection; both are caused by the same bacteria, of which several subgroups, or types, exist. (Viral meningitis also exists but is a less serious disease.) Of the types, five—A, B, C, Y and W-135— are responsible for most cases worldwide. In western countries, types B and C are major threats, whereas A, C, Y and W-135 are prominent in Africa and Asia. Contracting one does not confer immunity for another, and so wily are the microbes that they can convert from one type to another to ensure their survival.

It’s crucial to know IMD is always a medical emergency. It spreads voraciously with each passing hour and survival itself becomes a race against time. It’s not an illness you can sleep off, warns Elaine Hamlyn—indeed, trying to do so can cost you your life. Even quick antibiotic treatment doesn’t guarantee survival, or prevent long-term consequences like brain damage or amputation. Once symptoms appear, or you think you’ve been exposed to the bacteria, get to a hospital as fast as possible. Since this isn’t always an option when travelling, planning for an IMD encounter would seem wise. In fact, says Dr. Ronald Gold, an infectious disease and meningitis expert, off-the-path travellers are at higher risk for IMD because they often bunk with local populations, where prolonged exposure to carriers is possible. People who live or work abroad in at-risk zones are also vulnerable. Thankfully, newer, more efficacious vaccines have been developed in the past decade. Travellers might take a cue from Prince Edward Island and New Brunswick, which immunize their youth populations using a combined vaccine for most types. Gold, who favours this four-in-one vaccine as a national policy, recommends it too for travellers when the situation fits. Unhappily, there’s no vaccine for type B—so beware its symptoms, even if protected against the other four. Lacey Hamlyn was immunized against type C, then almost lost her life to type B.

This entry was posted on Friday, September 25th, 2009 at 4:16 pm and is filed under Health. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a comment, or trackback from your own site. Add to del.icio.us.