Streptococcal Meningitis

What is Streptococcal Meningitis?

Streptococcal meningitis is a serious condition where the protective coverings of the brain and spinal cord, known as membranes, become inflamed due to infection from streptococcal bacteria. When we talk about bacterial meningitis, it’s a severe, life-threatening infection that can lead to death if treatment isn’t started quickly.

Even though we’ve seen improvements in how we diagnose and treat this disease, as well as the introduction of vaccines, bacterial meningitis remains one of the most challenging infections across the globe.

What Causes Streptococcal Meningitis?

Many different types of Streptococcus bacteria can cause meningitis, which is an inflammation of the membranes surrounding your brain and spinal cord. One of the most common types is Streptococcus pneumoniae, which is likely the leading cause of meningitis all around the world, for both adults and children.

A different type of Streptococcus, called Group B Streptococcus (GBS), is the most common cause of meningitis in newborns and young infants.

There are other types of Streptococcus bacteria, like those in the S. viridans group or group A, but these rarely cause meningitis in either adults or children.

Risk Factors and Frequency for Streptococcal Meningitis

Streptococcal meningitis is an infection caused by different types of Streptococcus bacteria, which varies depending on the patient’s age. The most common type in children over a month old and adults of all ages is caused by Streptococcus pneumoniae. In the U.S., the number of cases of this type of meningitis has decreased since 1997. It is also the main cause of bacterial meningitis in children worldwide. In developing countries, it is a significant health issue, causing up to one million deaths each year in children under five.

However, in newborn babies, Streptococcus agalactiae is one of the main causes of meningitis. In the U.S., cases of this type of meningitis occurring within the first week of a baby’s life have decreased from 2006 to 2015, mainly due to the use of antibiotics during childbirth. However, cases in babies older than a week remained stable during these years. The global rate of this type of disease in babies is 0.49 per 1000 births, with the highest numbers in Africa. Other types of Streptococcus bacteria rarely cause meningitis.

• Streptococcus pneumoniae is the most common cause of meningitis in children over a month old and adults.
• Its incidence has dropped in the U.S. since 1997.
• It’s the top cause of bacterial meningitis in children.
• This infection causes up to 1 million deaths per year in children under five in developing countries.

• Streptococcus agalactiae is one of the leading causes of meningitis in newborns.
• In the U.S., cases in babies under a week old have decreased from 2006 to 2015 due to antibiotic use.
• However, the rate of cases in babies over a week old has remained the same.
• Globally, this infection occurs in 0.49 out of every 1000 births, with most cases in Africa.
• Other types of Streptococcus bacteria rarely cause meningitis.

Signs and Symptoms of Streptococcal Meningitis

Bacterial meningitis symptoms, such as those caused by Streptococcus, can appear suddenly or develop over a few days, typically showing up 3 to 7 days after exposure. It’s challenging to identify the specific bacteria causing meningitis just from the symptoms.

In adults, the main symptoms of meningitis are often fever, neck stiffness, and changes in mental state, although not all patients will have all three. Most patients will have at least two of these symptoms: a headache, fever, neck stiffness, or altered mental state. Other common symptoms include severe headache that gets worse when moving the head, feeling sick, vomiting, and sensitivity to light. However, these symptoms alone are not very reliable in diagnosing meningitis. If a patient doesn’t have at least two of these four symptoms, it’s highly unlikely that they have meningitis. During a physical examination, a doctor might look for signs of irritation in the membranes covering the brain and spinal cord, although these signs are not always present.

More specific signs like a bulging soft spot on the head, neck stiffness, and seizures are usually seen later in the illness. These symptoms can be harder to spot in babies younger than six months. However, reduced feeding, seeming very sick, being lethargic or unconscious, neck stiffness, and a bulging fontanel are usually associated with meningitis in children between two months and three years of age.

Testing for Streptococcal Meningitis

The key to diagnosing meningitis, including types caused by streptococcus bacteria, involves testing the cerebrospinal fluid (CSF). This fluid is found around and inside your brain and spinal cord, forming a cushiony layer. This test can confirm whether you have meningitis, identify the type of bacteria causing it, and help tailor your treatment.

To get this fluid, your doctor will perform a lumbar puncture (LP), often called a ‘spinal tap’, as soon as meningitis is suspected. However, if there’s a chance of serious side effects like brain herniation (a dangerous condition where brain tissue pushes into areas it shouldn’t), abnormal blood clotting, or if the patient is critically ill, they might hold off on the lumbar puncture.

Before the lumbar puncture, the doctor might order a head CT scan if you have focal neurological deficits (like specific, localised issues with brain function), changes in consciousness levels, swelling in the optic nerve that can suggest increased brain pressure, recent seizures, history of brain disease, or a weakened immune system.

The lumbar puncture involves extracting samples of the CSF for examination. This fluid will be checked for its physical and chemical make-up, cell count, and presence of bacteria. It will also undergo a Gram stain test, which helps identify bacteria types, and a latex agglutination test (LAT), which detects certain bacterial antigens. If available, a polymerase chain reaction (PCR) test will be done to detect bacterial DNA.

In cases of streptococcal meningitis, the CSF might show signs like high white blood cell count (indicating infection), elevated lactate level (another indicator of infection), and a lowered CSF/serum glucose ratio (a measure comparing sugar levels in your CSF and blood).

Unfortunately, some findings like a low white blood cell count and high protein level in the CSF could suggest worse outcomes in children with pneumococcal meningitis. An initial bacterial hint can be found through a Gram stain of the CSF, while the LAT might pick up specific bacteria such as streptococcus pneumoniae.

The definitive way to identify the bacteria causing the meningitis is by culturing a CSF sample. However, sometimes the bacteria do not grow in the lab cultures. In these instances, a PCR test can be used as it can detect bacterial DNA even if the bacteria do not grow in lab cultures. The PCR test’s relevance has been growing, though it can only identify certain types of bacteria.

Complementary to CSF testing, other lab tests will be carried out. This includes a blood culture to help further identify the bacterial cause, a complete blood count to assess your overall health and detect disorders like infections or anemia, and tests to measure inflammation, blood clotting, liver and kidney function. It is crucial not to delay treatment while waiting for the test results.

Treatment Options for Streptococcal Meningitis

Streptococcal meningitis, an infection in the brain and spinal cord caused by streptococcus bacteria, requires immediate medical attention. This condition needs quick action because any delay in treatment can lead to severe complications.

Treatment strategy often begins with antibiotics, which are medicines that kill or stop the growth of bacteria. For pneumococcal meningitis, caused by a bacterium named Streptococcus pneumoniae, antibiotics like vancomycin and either cefotaxime or ceftriaxone are usually given at first. However, this therapy may change when the doctor gets results from lab tests showing which antibiotics can kill the specific bacteria causing the infection. At that point, if the bacteria are found to be sensitive to penicillin, this medicine can replace the original antibiotics. For any patient who is known to have severe allergic reactions to either cephalosporins or penicillins, a different type of antibiotic known as chloramphenicol can be used as an alternative.

Some doctors also add another type of medicine, called dexamethasone, to the antibiotics for pneumococcal meningitis patients. Studies have shown that this approach brings down the rate of death and other unfavorable outcomes when compared to using antibiotics alone.

On the other hand, if the meningitis is caused by group B Streptococcus (S. agalactiae) or group A Streptococcus or S. viridans, penicillin G is the main treatment option. If penicillin G cannot be used, ampicillin can be an alternative for group B Streptococcus.

Apart from antibiotics, supportive care plays a crucial part in treating this condition. This involves measures like controlling the amount of fluids in the body, reducing the pressure in the brain, managing fever and pain among many others. This approach helps in dealing with symptoms and supporting the body’s combat against the infection.

What else can Streptococcal Meningitis be?

When diagnosing certain brain and nervous system infections, there are many other conditions that need to be ruled out because they can present similar symptoms. For example, different types of bacterial meningitis can be easily confused. A test called a CSF Culture is needed to figure out the exact cause. Besides bacteria, viruses and fungi can also cause meningitis and must be excluded. Encephalitis, a brain inflammation, can also look similar to meningitis, but it’s different due to evidence of brain inflammation that is not present in meningitis. Other causes of altered mental status and coma such as stroke, drug intoxication, low blood sugar, and electrolyte disturbances should also be excluded.

Other conditions that could be mistaken for these neural infections include:

• Brain abscess
• Brain tumors
• Subdural or epidural abscess
• Leukemia of the central nervous system (CNS)
• Adverse reactions to certain medications
• Tuberculosis of the CNS
• Disorders related to blood vessel inflammation, like Kawasaki disease and collagen vascular disease
• Lead encephalopathy
• Encephalitis
• Stroke
• Low blood sugar (hypoglycemia)
• Drug intoxication
• Viral meningitis
• Fungal meningitis

What to expect with Streptococcal Meningitis

Streptococcal meningitis is a serious condition. A Danish research study found that 21% of people with this type of meningitis did not survive, and that adults are ten times more likely to die from the disease than children. There are several reasons why streptococcal meningitis can be fatal such brain damage, stroke-related complications, systemic causes like septic shock, failure of multiple organs, and other causes. About one third of the patients die due to both systemic and brain-related complications.

In this study, several factors contributed to these fatalities such as being very old, having a lung focus (an area of infection in the lung), experiencing convulsions, having a CT scan before a lumbar puncture, and needing assisted breathing. Interestingly, if the infection originated in the ear, patients had a better chance of survival.

The study also found that symptoms such as falling into a coma, having difficulty breathing, experiencing shock, and having leukopenia, a condition characterized by low numbers of white blood cells, indicated a poor prognosis in children with meningitis.

Mortality rates for Group B Streptococcus (GBS) meningitis in newborns have decreased due to the use of prophylactic treatment during labor and delivery. This treatment is given to prevent the newborn from getting the infection. However, the mortality rate is still high at 11.4 percent. Additionally, it’s common for survivors to experience long-term neurological and systemic health issues.

Possible Complications When Diagnosed with Streptococcal Meningitis

Survivors of pneumococcal meningitis often experience serious brain-related complications. One study found that over 70% of patients suffered from complications after pneumococcal meningitis while over a third experienced body-wide complications. These problems ranged from seizures and brain swelling to hearing loss, brain damage, and fluid build-up in the brain. Another study found that nearly two-thirds of patients had neurological deficiencies, with hearing loss being the most common.

In children, the most recurring long-term issue from post-pneumococcal meningitis was developmental delay, affecting nearly half of children studied. Around a third of survivors had seizures a year after infection, with 29% experiencing hearing loss. For children who had a specific type of meningitis called GBS, one in four had mild to moderate issues, and close to one-fifth showed severe long-term problems.

Complications for Adults:

• Seizures
• Brain Swelling
• Hearing loss
• Brain damage (ischemic or hemorrhagic)
• Fluid build-up in the brain (hydrocephalus)

Complications for Children:

• Developmental delay
• Seizures
• Hearing loss
• Impairments from GBS meningitis

Preventing Streptococcal Meningitis

It’s very important for patients to understand about Streptococcal meningitis, a type of bacterial infection in the brain and spinal cord. You should also be aware of the severe warning signs related to this condition. Acting quickly when these symptoms appear is crucial because any delay in treatment can lead to worse outcomes.

Pregnant women need to be aware that they may be given drugs during labor and delivery (called intrapartum chemoprophylaxis) to prevent the transmission of bacteria to the baby. This is something that your pregnancy doctor (obstetrician) should discuss with you. Remember, the more you understand about what’s happening, the better it is for your health and your baby’s health.