What is Meningococcal Meningitis?
Meningitis is an infection that leads to swelling in the layers that surround the brain and spinal cord, known as the meninges. A type of bacteria called Neisseria meningitidis causes a specific kind of this infection, which we call meningococcal meningitis. This form of meningitis is known to be very severe and can lead to death or serious health problems. Meningococcal meningitis is a medical emergency that may show symptoms ranging from a temporary fever to a sudden, severe blood infection and shock.
What Causes Meningococcal Meningitis?
Neisseria meningitidis is a bacteria that causes a disease called meningococcal meningitis. This particular bacteria is one of the most common causes of bacterial meningitis in the United States. It’s shaped like a bean or kidney, and grows best in certain environments, such as with certain levels of carbon dioxide that are similar to room temperature.
Interestingly, this bacteria utilizes a few different components to survive and thrive. For example, it changes the pH levels by oxidizing, or breaking down, glucose and maltose (types of sugars). This feature helps distinguish it from a similar bacteria that can’t oxidize maltose. Neisseria meningitidis also grows in an environment that includes certain antibiotics, allowing it to outcompete other types of bacteria and yeast.
This bacteria generally lives in the nose and throat, but can also be found in other parts of the body like the conjunctiva of the eye, digestive tract, and the urinary tract. It has several features that help it infect humans, including a shielding armor that protects it from the body’s immune system.
The types of Neisseria meningitidis, called serotypes, can vary with different kinds. There are 13 serotypes, with types A, B, C, X, Y, Z, W-135, and L being the most harmful to humans. There also are rare strains that do not produce harm. This bacteria’s makeup also includes a component similar to that of other harmful bacteria, which can trigger inflammation in the body leading to meningococcal sepsis, a severe blood infection.
Certain factors can increase one’s risk of getting infected with this bacterium. For instance, people with a weakened immune system, such as military recruits or people living with HIV/AIDS, have a higher chance of developing meningitis. The bacteria spreads via carriers – people who have the bacteria in their noses or throats but aren’t sick – which is why vaccination is crucial among high-risk groups. Also, people on a medication called eculizumab have a significantly higher risk of a fatal infection with this bacterium.
Risk Factors and Frequency for Meningococcal Meningitis
N. meningitidis, a bacteria often responsible for a major health condition known as meningitis, impacts about 1.2 million people every year, contributing to roughly 135,000 deaths globally. Infants and teenagers are more likely to contract this disease due to higher rates of nasal bacteria and decreasing levels of antibodies received from their mothers. In the United States, the yearly rates of meningitis from 2006 to 2015 were around 0.28 instances per 100,000 people. For babies under one year, the number was higher, around 2.50 instances per 100,000. However, the highest incidence of meningitis is found in sub-Saharan Africa, known as the “meningitis belt,” with rates varying from 20 to 1,000 per 100,000 people.
The type of meningococcal disease can differ depending on the location. For instance, meningococcus serogroup A is more common in Africa and parts of Asia. On the other hand, serogroups B, C, and Y are more common in North America and Europe. In the U.S, B, C, and Y serogroups are the prominent causes of meningitis, with each one responsible for approximately one third of the cases. Among these, serogroup B causes 50% of the cases in infants, serogroup C is seen frequently in teens, and serogroups B and Y are common in older adults.
- Between 2006 and 2015:
- The annual rate of meningitis dropped from 0.40 to 0.14 cases per 100,000.
- For serogroup B, the rate went down from 0.25 to 0.05 cases per 100,000.
- For serogroup C, the incidence decreased from 0.38 to 0.01 cases per 100,000.
- For serogroup Y, the rate changed from 0.42 to .02 cases per 100,000.
- However, the rate of infection from other serogroups remained the same.
Men are found to be slightly more affected by this infection than women. In terms of race, the infection rate is higher among African-Americans (0.27 cases per 100,000) compared to other races (0.20 cases per 100,000). Despite advances in medical technology and prevention methods, the death rate remains between 5% and 15% among those who receive treatment, and can reach up to 50% for those who do not get treatment.
Signs and Symptoms of Meningococcal Meningitis
Bacterial meningitis is a severe infection that urgently needs to be recognized and treated. This disease can present with a range of symptoms, from a basic fever to severe septic shock. The progression of the symptoms is usually swift, taking only a few hours. This rapid progression can be a useful way to distinguish meningitis from a standard viral infection.
The traditional signs of meningitis include neck stiffness, fever, and changes in mental state. Infants with the disease might show symptoms like lethargy, irritability and occasionally, a bulging soft spot on their head. Older children and adults can experience symptoms like headaches, fever, light sensitivity, vomiting, neck stiffness, and changes in mental state. A rash with small red or purple spots can also appear on lower extremities, which often develops after the initial non-specific symptoms. Muscle aches, more painful than those associated with viral influenza, can also occur. Other early signs of sepsis, such as leg pain, cold hands and feet, and unusual skin color, should also be monitored.
- Neck stiffness
- Fever
- Changes in mental state
- Lethargy or irritability (in infants)
- Headaches
- Light sensitivity
- Vomiting
- Rash with small red or purple spots
- Severe muscle aches
- Signs of early sepsis (leg pain, cold hands and feet, unusual skin color)
Upon a physical examination, the patient may exhibit abnormal vital signs such as fever, rapid breathing, rapid heart rate, and low blood pressure. If the patient’s heart rate is high and their blood pressure is low, it may suggest early signs of vascular instability. The patient should be undressed to check for the presence of small red or purple spots and for an overall skin check. Tests, like the Kernig and Brudzinski signs, can be done to confirm the irritation of the meninges, the membranes covering the brain and spinal cord. It is also critical to perform a thorough neurological exam to check for any changes in mental status or specific neurological deficits. The absence of these signs does not necessarily mean the patient does not have systemic meningococcal infection, the bacteria that often cause meningitis.
Testing for Meningococcal Meningitis
If your doctor suspects you might have meningitis, a variety of initial blood tests could be done, looking at your overall blood cell count, the balance of your bodily salts (electrolytes), and your blood’s clotting ability. They may also check your blood for harmful bacteria. However, to be completely certain, a procedure called a lumbar puncture might be needed.
A lumbar puncture involves drawing fluid from your spine, which can potentially show the presence of N. meningitidis, a type of bacteria often involved in meningitis. This fluid can show signs of infection, like an increased number white blood cells, high protein concentrations, and low glucose (sugar) levels. But even if your results come back clean in two hours, this should not delay starting antibiotics if your doctor highly suspects you have meningitis.
The spinal fluid can also be used for various other tests to refine the diagnosis. These include a test called Gram staining, culturing the fluid to encourage bacterial growth, and Polymerase Chain Reaction (PCR). The Gram staining technique can be diagnostic in 85% of patients with meningococcal meningitis if N. meningitidis is present. A culture test can definitively diagnose meningitis by promoting the growth of bacteria under specific conditions. PCR is an advanced test that can identify the DNA of the bacteria and is faster and more specific than a culture test. However, it can sometimes provide false-negative results.
In addition to these lab-based tests, if your symptoms are severe or match certain criteria, your doctor may order imaging tests, such as a CT scan. These criteria might include being older than 60, having some focused neurological deficits, memory difficulties, a weakened immune system, new and sudden seizures, a past of disorders involving the brain or spinal cord, and a swollen optic nerve (papilledema).
Treatment Options for Meningococcal Meningitis
Meningococcal meningitis is a serious health emergency. It causes symptoms like fever and skin discoloration due to bleeding under the skin and can quickly become severe enough to lead to organ failure. This illness requires immediate medical attention, which usually includes both stabilizing the patient and giving them antibiotics.
As part of stabilizing the patient, doctors will look at how stable the patient’s internal state is, like their blood pressure and organ function, to see if they need immediate interventions. Patients might need to be put on a breathing machine if their airways are compromised, they’re having ongoing shock, they’re experiencing uncontrollable seizures, or their brain pressure is high. Doctors will also work on maintaining the patient’s blood pressure and ensuring their tissues have sufficient blood supply through giving them fluids and medications, due to the threat of organ failure and shock commonly seen in such cases.
Doctors aim to start antibiotics as soon as meningitis is suspected, without waiting for tests to confirm the diagnosis. This is important because, once started, antibiotics can reduce the amount of meningococcal bacteria in the cerebrospinal fluid (fluid around the brain and spinal cord) in just hours. They generally begin with broad-spectrum antibiotics, which can target a wide range of bacteria, until they can identify the specific kind causing the illness. Generally, a week-long course of antibiotics is used to treat suspected cases of meningococcal meningitis. For adults, usual antibiotics include certain types that are highly effective against meningococcal bacteria. Additional antibiotics are also used for patients over 50 years old to cover other potential bacteria that can cause similar symptoms. Once meningococcal meningitis has been confirmed, doctors often switch to a simpler, cheaper antibiotic due to its effectiveness and lower risk of side effects. If a patient can’t tolerate certain antibiotics, or in outbreaks or in areas with limited resources, an alternate antibiotic is chosen.
Traditionally, some doctors give their patients a dose of a steroid medication, but this has been debated because it might only benefit patients whose meningitis was caused by other bacteria, not the meningococcal bacteria.
The disease can be prevented by certain measures. This includes droplet precaution, which involves wearing protective gear if you’re in close contact with a patient until they’ve been on antibiotics for 24 hours. There is also a vaccine available in the United States, which is recommended for all individuals between ages 11 and 18, as well as anyone who might be at higher risk of contracting the disease, such as travellers to areas with high numbers of cases, military recruits, those working with the bacteria in labs, and those with certain diseases or conditions that make them less able to fight infections. The vaccine is usually given two weeks before beginning treatment with a medication that impairs the body’s ability to fight off meningococcal disease.
Patients and healthcare workers who have been in close contact with someone diagnosed with meningococcal meningitis should also take antibiotics as a preventive measure. If the bacteria in question are resistant to the initial choice of antibiotic, other antibiotics are considered as alternatives. Additionally, for the duration of the treatment, patients who are on medications that inhibit their body’s ability to defend against the bacteria should receive preventive antibiotics in addition to the vaccine. These individuals and their close contacts should be watched closely for 10 days after exposure, to ensure quick treatment if they were to develop meningitis.
Lastly, patients who are known carriers of meningococcal bacteria, even if they don’t have symptoms, should get preventive antibiotics before leaving the hospital to prevent spreading the bacteria.
What else can Meningococcal Meningitis be?
When trying to diagnose a neurological condition, medical professionals need to consider a list of other possible illnesses that might share similar symptoms. These could include:
- Encephalitis (caused by bacteria or viruses)
- Brain abscess
- Cancer
- Bleeding in the brain
- Stroke
- Tetanus
- Rabies
- Reactions to medications that could cause serotonin syndrome or neuroleptic malignant syndrome
- Sinusitis
It’s also important to note that meningococcal meningitidis can progress to meningococcemia, which is marked by a purpuric rash. This condition can be difficult to distinguish from:
- Sepsis
- Disseminated gonococcemia
- Rocky Mountain Spotted Fever
- Endemic or epidemic typhus
- Leukocytoclastic vasculitis
- Hemorrhagic dengue
- Ehrlichiosis
- Anaplasmosis
- Lyme disease (Borreliosis)
- Thrombotic thrombocytopenic purpura
- Idiopathic thrombocytopenic purpura
Therefore, careful evaluation and testing are necessary for accurate diagnosis.
What to expect with Meningococcal Meningitis
The Centers for Disease Control and Prevention states that in the U.S., about 10% to 15% of people with meningococcal meningitis who get treatment may die, and this number can rise to 50% if it’s not treated. The word ‘mortality rate’ here refers to the percentage of people who die from a certain disease. Meningococcal meningitis is an infection that causes serious swelling in the brain and spinal cord. Getting antibiotics as quickly as possible—ideally within an hour—has shown to reduce not only the death rate but also the severity of the disease and the risk of complications like increased pressure inside the skull or a severe bloodstream infection known as septic shock.
There are several factors that can worsen the outcome for patients with meningococcal meningitis. These include:
- Shock, a dangerous drop in blood flow through the body
- Distinct neurological problems, called ‘focal deficits’
- Being confused or in a coma
- A type of skin rash that indicates bleeding beneath the skin, known as ‘purpuric’ or ‘ecchymotic’ rash
- Not showing signs of a stiff or painful neck, a typical symptom of meningitis
- Having a low or normal white blood cell count when it’s usually high in infections
- Being older than 60 years
- Having anemia, a condition that makes you lack enough healthy red blood cells
- Having a low platelet count, called thrombocytopenia, which can lead to abnormal bleeding
- Having low levels of certain blood proteins and high levels of a molecule in the blood that can influence blood clotting
- Having cancer
- Having bleeding inside the skull (intracranial bleed) or a stroke, also known as a ‘cerebrovascular accident’
On top of these, being a woman and getting the disease during an outbreak have also been linked to a higher risk of death from meningococcal disease.
Possible Complications When Diagnosed with Meningococcal Meningitis
Meningococcal meningitis is a serious disease that can lead to a variety of complications, which might show up earlier or later in the illness. These issues can negatively affect a person’s health and, in some cases, can cause death. Complications from within the brain include cerebral edema (swelling), alterations in blood vessels, and hydrocephalus (excessive accumulation of fluid in the brain). Other complications outside the brain can range from septic shock and disseminated intravascular coagulation (a condition affecting the blood’s ability to clot and cause bleeding), to failure of multiple organs like the adrenal gland due to bleeding (Waterhouse-Friderichsen syndrome), and imbalance of electrolytes in the body.
Furthermore, delayed complications of the disease include chronic pain, scarring of the skin, and neurological issues. Additional common complications encompass hearing loss, vision problems, and seizures. It’s recommended that patients undergo hearing tests four weeks after being discharged from the hospital. Post-traumatic stress disorder (PTSD) can also occur as a result of the stress of the disease, and this may necessitate psychiatric or psychological treatment.
Like any severe illness, other complications may also arise, such as the need for prolonged respiratory support, long-term care for a tracheostomy (opening in the neck for breathing), and feeding tube care. Other complications can involve a lengthy process of physical and occupational rehabilitation, development of polyneuropathy (damages to peripheral nerves), and polymyopathy (muscle weakness) because of the critical illness. Patients may also develop secondary infections and wounds.
Common Complications:
- Inside the brain: cerebral edema, blood vessels alterations, hydrocephalus
- Outside the brain: septic shock, disseminated intravascular coagulation, multiorgan failure, adrenal gland failure from bleeding, electrolyte imbalances
- Delayed effects: chronic pain, skin scarring, neurologic impairment
- Other complications: hearing and visual impairment, seizures
- PTSD
- Prolonged respiratory support needs, tracheostomy care, feeding tube care
- Long-term physical and occupational rehabilitation
- Polyneuropathy, polymyopathy
- Secondary infections and wounds
Preventing Meningococcal Meningitis
The best way to prevent Meningococcal disease, a serious illness that can cause infection in the brain and spinal cord, is through vaccination. Thanks to the introduction of vaccination programs, we’ve seen a significant drop in the number of people getting sick from this disease. In the US, health guidelines suggest getting a special type of vaccine, called a quadrivalent vaccine, when you’re 11 to 12 years old and then again when you’re 16. This second shot helps to ensure that you’re protected for another 3 to 5 years, during a time when you may be more at risk.
It’s really important to take steps to prevent this disease, because Meningococcal disease can become very serious, very fast – it can even lead to death. So, getting vaccinated is a priority.
