An Update on Meningitis

In the United States and other developed nations, bacterial meningitis is increasingly being viewed as an “historical” disease — a disease consigned to the history books. This is due to the availability of vaccines combined with relatively low instances of infection.

But unlike polio or Hansen’s disease (leprosy), nearly all new cases of which are brought to the United States from abroad, bacterial meningitis (primarily meningococcal meningitis) remains endemic to this country. And while the incidence rate is low (ranging from 900 to 3,000 cases of meningococcal meningitis infections per year), bacterial meningitis remains a life-threatening disease, one that claims several hundred lives annually.¹

Around the world, meningitis is an even more serious health problem. In Brazil, sub-Saharan Africa and parts of India, infection rates are five times greater than in the U.S. and Europe. And, while reliable statistics are not always available, rates of up to 800 per 100,000 population have been reported — compared to rates of five per 100,000 or fewer in the developed world.²

Not only is it a challenge to effectively diagnose and treat meningitis, but the various types are symptomatically indistinguishable from one another. And since the treatments vary widely depending on the cause of infection, an accurate diagnosis is critical. Only a culture of cerebrospinal fluid can confirm the cause of the meningitis infection.

While viral meningitis is typically less dangerous than bacterial, the quickly developing nature of a bacterial infection (often measured in hours) and its lethal potential indicate that all cases of meningitis should be approached at first as if caused by the meningococcus or other bacteria, since their treatment is the most time-sensitive.

What Is Meningitis?

Meningitis is the name given to any inflammation of the protective coverings of the brain and spinal column, which are known as the meninges.³

The Centers for Disease Control and Prevention (CDC) classifies meningitis into five categories, based on what causes the infection.⁴ Viral are the most common, followed by bacterial. Fungal and parasitical infections (which can be as serious as a bacterial meningitis infection) are very rare, and even rarer are noninfectious causes, such as cancer, head injuries and some drugs.⁵

Any form of meningitis poses risks to the patient, as the swelling can cause injury to the brain and/or spinal column. Viral infections tend to run their course without treatment and without serious long-term impacts on the patient. But the more dangerous forms (most typically meningococcal meningitis) may lead to brain damage, hearing loss and even severe infection of limbs resulting in amputation.⁶

Symptoms of Meningitis

In its early stages, any form of meningitis can manifest similarly to flu; Fever, nausea and vomiting, and headache all are common symptoms. It is possible to distinguish between meningitis and flu if the patient presents with symptoms of confusion and stiff neck, or a sudden sensitivity to light.⁶

Treating Meningitis

When meningitis is suspected, the CDC recommends immediate testing of the cerebrospinal fluid to determine the cause. The severity, and even potential fatality, of the infection can be lowered through timely, effective treatment.

As mentioned, most cases of viral meningitis run their course in a few weeks without intervention. The typical treatment for viral meningitis is bed rest and fluids for seven to 10 days.

Depending on the specific virus (enteroviruses and herpes simplex are the two most common), 6 antivirals can be introduced in rare situations to help fight a severe infection. While less serious than other forms and rarely life-threatening, viral meningitis typically takes longer to recover from — with headaches, memory loss and fatigue often lasting months and sometimes even longer following a severe case.⁷

Although fungal and parasitical sources of meningitis can be as deadly as bacterial meningitis, they also are extremely rare. The CDC reports that effective treatments with antifungals are available;⁸ however, amoeba-caused meningitis is not currently treatable and is nearly always fatal.⁹

For bacterial meningitis, the antibiotics treatment will depend on the specific bacteria causing the infection, as determined by the cerebrospinal fluid culture. According to the CDC, the type of bacteria causing meningitis is associated with the age of the patient (although exceptions are common). With newborns, the most common causes are Group B Streptococcus, Escherichia coli and Listeria monocytogenes. For infants and children, they are Streptococcus pneumoniae, Neisseria meningitidis (meningococcus) and Haemophilus influenzae type b. Adolescents and young adults are most susceptible to Neisseria meningitidis (meningococcus) and Streptococcus pneumoniae. The elderly are most prone to infection from Streptococcus pneumoniae, Neisseria meningitidis (meningococcus) and Listeria monocytogenes.

Preventing Meningitis

While effective treatments for bacterial meningitis are widely available, the CDC still recommends inoculation as the best approach.¹⁰

There are effective antibiotics to treat the various bacteria that can cause meningitis, but there also are three different vaccines available to help prevent most cases of bacterial meningitis. Neisseria meningitidis (meningococcus), Streptococcus pneumoniae (pneumococcus) and Haemophilus influenzae type b (Hib) all have vaccines available to prevent infection.¹¹

The Hib vaccine is already part of the normal childhood regimen of inoculations. 11 But, the pneumococcal conjugate vaccine also is recommended by the CDC for all children, as well as for the elderly.¹²

For the meningococcal bacteria, there are currently two vaccines available in the United States: MCV4 and MPSV4. The CDC recommends that all children receive one of these vaccines between ages 11 and 12, as well as a booster at age 16.

Studies show that young people living in close proximity are at higher risk of contracting bacterial meningitis than the population at large. Therefore, many colleges and universities now require proof of a recent booster for admission. In addition, military recruits are advised to receive an immunization or booster, as barracks are not much different from dorm rooms when it comes to pooling bacteria among a population.

Those traveling to areas of the world where meningococcal meningitis is prevalent should also receive an inoculation or booster.

Certain high-risk infants also may be recommended for vaccination. 13 In addition, the chicken pox and measles, mumps and rubella (MMR) vaccines will help prevent infection by several of the viruses that can cause meningitis.¹⁴

To prevent viral meningitis, hygiene is a key factor. Washing one’s hands with hot water and soap can kill many of the viruses that can cause meningitis. Particularly important is paying attention to hygiene when changing diapers, before and after meals, and when using the bathroom.

The Importance of Vaccination

The CDC, the American Medical Association15 and private patient-support organizations such as the National Meningitis Association (United States) and the Meningitis Trust (United Kingdom) all advocate for the importance of vaccinations, and they point out that vaccinations are highly tested and have established records of safety.

With the recent push-back against vaccinations from some parents (often influenced by conspiracy-theory advocates), it can oftentimes be a challenge for pediatricians to convince parents to inoculate their children with all the recommended vaccines — particularly those to prevent a disease like meningitis with a low rate of occurrence in this country.

Therefore, it is important that parents realize how dangerous meningitis is (particularly bacterial meningitis), and how quickly it can strike. Even among the majority of patients who survive, many will suffer for years from brain damage and its effects, including learning disabilities, speech impediments and worse. When counseling parents and young adults, it is imperative that they have all the information relevant to the risks — both of the vaccine, and of not being vaccinated.