The Fight Against Bacterial Meningitis And Meningococcemia Isn't Over
Anyone who's spent time on a college campus has likely heard a lot about bacterial meningitis in recent years. Adolescents and young adults already have a higher susceptibility to this type of infection than other age groups — except infants — and the crowded environment of college can increase that risk.
That said, anyone can come down with bacterial meningitis, or the related and more fatal meningococcemia, which is caused by the bacteria Neisseria meningitidis. Both of these are forms of what the medical profession calls meningococcal disease. Bacterial meningitis tends to be more severe than viral meningitis, and it can escalate rapidly if not properly diagnosed and treated.
Vaccines against meningococcal disease have slashed the rate of these infections in the industrialized world. But despite this progress, people who do get meningococcal disease can still face serious consequences — amputations, brain damage and death. In recent decades, public health officials have put an emphasis on prevention, encouraging more people to get informed and get vaccinated.
Three people who have personal experience with the disease on the University of Wisconsin-Madison campus spoke at a May 13, 2015 edition of the Wednesday Nite @ the Lab lecture series. Their presentation was recorded for Wisconsin Public Television's University Place.
Meredith Leigh, whose son Henry Mackaman died of bacterial meningitis in 2013 while he was attending UW-Madison, began the presentation. She described the work she's been doing with the National Meningitis Association, but also stressed that she wants people to remember her son for how he lived and not just how he died. Leigh was followed by two officials from UW-Madison's University Health Services — epidemiologist Craig Roberts and executive director Sarah Van Orman — who delved into the clinical side of meningococcal disease and the need for proper prevention and treatment.
All three speakers, especially Van Orman, detailed the progress that has been made with reducing incidence of the disease, but also emphasized that there's still much more work to do.
- Meningitis is when the bacteria (or, in the viral form, a virus) enters and inflames the membranes surrounding the brain and spine. Meningococcemia is when the bacteria enters the bloodstream. The two can happen simultaneously.
- Meningococcal disease is considered relatively rare in the United States. In 2013, according to the Centers for Disease Control and Prevention, about 550 cases were reported in the U.S., or about .18 cases per 100,000 people.
- Neisseria meningitidis typically first infects the nasopharynx, and from there can spread to the bloodstream and/or central nervous system. Researchers have identified 13 different serogroups, or subtypes, within this bacterial species, five of which are known to cause meningococcemia. Whichever serogroup causes disease, though, the symptoms tend to be pretty similar.
- Coughs, sneezes, and saliva exchange (through kissing or sharing drinks, for instance) typically spread Neisseria meningitidis. The bacteria itself is fairly common: epidemiologists believe that at any given time, about 10 percent of the population is carrying it in their throats. Most of the time, though, it does not actually cause disease among people who are carriers.
- Early symptoms of meningococcal disease tend to resemble those of common viral infections like colds or influenza, including fever, headaches, and fatigue. This expression of the infection makes it difficult for healthcare providers to accurately diagnose meningococcal disease.
- Symptoms of meningococcal disease can escalate within a very short period of time, sometimes just a few hours, to manifestations as severe as numbness, seizures, strokes and brain damage. Those latter symptoms are much more common with bacterial meningitis than with viral meningitis. Symptoms of meningococcemia include a rash on the hands.
- Meningococcemia can cause significant damage to an infected person’s blood vessels, sometimes to the extent that it cuts off blood supply to their extremities and the patient has to have one or more limbs amputated. This damage to blood vessels can also cause lasting damage to the brain and other organs.
- Infants are at the greatest risk of meningococcal disease by far, but adolescents and young adults are also at higher risks than most age groups.
- Much of the discussion of meningococcal disease focuses on college students and campuses. This is in part because college freshmen are living in close quarters with many other people for the first time, which challenges their immune systems and creates more opportunity for bacteria to cause disease.
- Overall, meningococcal disease in Wisconsin has a mortality rate of 10 percent. But among people who get meningococcemia, the mortality rate can be as high as 50 percent.
- Early meningitis vaccines, introduced in the 1970s, did not provide protection for very long periods. More advanced vaccines introduced in 2005 targeted four serogroups and helped drive down the incidence of meningococcal disease five-fold in the United States. Two newer vaccines, which have come into use just over the past three years, targets Serogroup B, which has become the most common over the last decade.
- Wisconsin state law requires the UW System to provide meningitis vaccines for college students.
- Roberts on the difference in severity between meningitis and meningococcemia: "Meningococcemia typically is worse because it represents basically blood poisoning with this bacteria and toxins are being released. It's a much more rapid onset and a much more rapid progression of disease, and it has a much higher fatality rate than just simple meningitis."
- Roberts on commonality of Neisseria meningitidis bacteria versus the rarity of the disease: "We do not really understand very well why this becomes invasive in some people and becomes a serious disease. Again, if 10 percent of our population is colonized at some point but one in 500,000 gets the disease, there's a huge gap between what happens in healthy people and why it's invasive."
- Roberts on the widely varying outcomes of meningococcal disease: "You've heard about some of the worst-case scenarios, and that's always what makes the news and what gets the attention. I have talked to students who've walked into the ER and walked out within an hour with that same diagnosis. They didn't even need to be admitted."
- Roberts on the often rapid progression of meningococcal disease: "There have also been people where this happens over a space of four, six, or eight hours, where they wake up feeling like it's a normal morning for them and they're dead by four o'clock or six o'clock that evening. That is something that is absolutely striking. Many college students and young adults don't tend to seek health care until they've been sick for a couple of days."
- Roberts on the reduced incidence of meningococcal disease on the UW-Madison campus: "At UW-Madison [20 years ago], we would probably see one or two students a year with meningococcal disease that needed to be hospitalized. Now we are typically seeing one case every two to three years, so that kind of fits with the national statistics."
- Van Orman on high vaccination rates among UW-Madison students: "Our overall rate for all students is about 87.7 percent, and for entering first-year students, it's 90.2 percent. We're always looking to increase those numbers...The largest group of students we see that don't have the vaccine are actually our incoming international students."
- Van Orman on the state of the two most recently introduced vaccines targeting serogroup B: "There's concerns that it may not provide long-lasting protection. It may not reduce carriage, and it may not lead to herd immunity. It's also multiple doses...It's absolutely great that we have the B vaccine available, but these current B vaccines as they are, the work is not done on an effective vaccine for serogroup B."
- Van Orman on the reduced incidence of meningococcal disease in the United States: "This is a great success story when it comes to vaccine-preventable diseases…[but] the work is absolutely not over yet."