How is meningitis diagnosed. What are the early signs of meningitis. Can meningitis be fatal if left untreated. How quickly can meningitis progress. What is the most reliable test for meningitis.

Understanding Meningitis: A Potentially Life-Threatening Condition

Meningitis is a serious inflammatory condition affecting the meninges, the protective membranes surrounding the brain and spinal cord. This inflammation can be caused by various factors, including infections from viruses, bacteria, fungi, or parasites. In some rare cases, non-infectious causes such as cancer or other diseases can also lead to meningitis.

The severity and urgency of meningitis cases can vary significantly depending on the underlying cause. Bacterial meningitis, for instance, is particularly dangerous and can progress rapidly, potentially leading to fatal outcomes within hours if left untreated. On the other hand, viral meningitis often resolves on its own without specific treatment.

Types of Meningitis

• Bacterial meningitis
• Viral meningitis
• Fungal meningitis
• Parasitic meningitis
• Non-infectious meningitis

Given the potential severity of meningitis, particularly in its bacterial form, it is crucial to seek immediate medical attention if meningitis is suspected. Early diagnosis and prompt treatment can significantly improve outcomes and prevent potentially life-threatening complications.

Recognizing the Signs and Symptoms of Meningitis

Identifying meningitis early is crucial for effective treatment. The symptoms of meningitis can develop rapidly and may vary depending on the type and cause of the infection. However, some common signs and symptoms are often present across different forms of meningitis.

Common Symptoms of Meningitis

• Sudden high fever
• Severe headache
• Stiff neck
• Sensitivity to light (photophobia)
• Nausea and vomiting
• Confusion or altered mental state
• Seizures
• Skin rash (in some cases)

Is there a specific symptom that definitively indicates meningitis? While no single symptom can conclusively diagnose meningitis, the combination of high fever, severe headache, and neck stiffness is often considered highly suggestive of the condition. However, it’s important to note that these symptoms may not always be present, especially in young children, elderly individuals, or those with compromised immune systems.

The Meningitis Rash and Glass Test

In some cases of bacterial meningitis, particularly those caused by meningococcal bacteria, a characteristic rash may develop. This rash typically starts as small, red pinpricks that can rapidly progress to larger, purple bruise-like marks. A key feature of this rash is that it does not fade under pressure.

The “glass test” is a simple method to check for this non-blanching rash:

1. Press a clear glass firmly against the skin where the rash is present.
2. If the rash does not fade and remains visible through the glass, it may indicate septicaemia (blood poisoning) associated with meningococcal meningitis.
3. This is considered a medical emergency requiring immediate attention.

Can the glass test definitively diagnose meningitis? While the glass test can be a useful indicator, it is not a definitive diagnostic tool. Some cases of meningitis may not produce a rash, and the rash may appear late in the course of the illness. Therefore, it’s crucial not to rely solely on the presence or absence of a rash when suspecting meningitis.

Diagnostic Procedures for Meningitis

When meningitis is suspected, a series of diagnostic tests are typically performed to confirm the diagnosis and identify the underlying cause. The cornerstone of meningitis diagnosis is the analysis of cerebrospinal fluid (CSF), which requires a procedure called a lumbar puncture or spinal tap.

Lumbar Puncture (Spinal Tap)

A lumbar puncture involves inserting a needle between the vertebrae in the lower back to collect a sample of cerebrospinal fluid. This fluid is then analyzed for various factors, including:

• White blood cell count
• Glucose levels
• Protein levels
• Presence of bacteria, viruses, or other pathogens

Is a lumbar puncture always necessary to diagnose meningitis? While a lumbar puncture is the most definitive test for meningitis, in some cases, treatment may be initiated based on clinical symptoms and other diagnostic tests if performing a lumbar puncture would delay treatment or if it’s contraindicated due to certain medical conditions.

Additional Diagnostic Tests

In addition to the lumbar puncture, other tests may be performed to aid in diagnosis or rule out other conditions:

• Blood tests: To check for signs of infection and inflammation
• Imaging studies: CT or MRI scans of the head to look for signs of inflammation or other abnormalities
• Throat and nasopharyngeal swabs: To identify potential infectious agents

These tests, combined with a thorough clinical examination and patient history, help healthcare providers make an accurate diagnosis and determine the most appropriate treatment approach.

Treatment Approaches for Meningitis

The treatment of meningitis varies depending on the underlying cause and the severity of the condition. Prompt initiation of appropriate treatment is crucial, especially in cases of bacterial meningitis, where delays can significantly impact outcomes.

Bacterial Meningitis Treatment

Bacterial meningitis is treated with intravenous antibiotics. The choice of antibiotics may initially be broad-spectrum to cover multiple potential pathogens and may be adjusted once the specific bacteria is identified. In some cases, corticosteroids may also be administered to reduce inflammation and the risk of complications.

How quickly should antibiotic treatment be started for suspected bacterial meningitis? Ideally, antibiotic treatment should be initiated as soon as bacterial meningitis is suspected, even before confirmatory test results are available. This prompt treatment can significantly improve outcomes and reduce the risk of severe complications or death.

Viral Meningitis Treatment

Most cases of viral meningitis resolve on their own without specific treatment. Management typically focuses on supportive care, including:

• Rest
• Adequate hydration
• Pain relief medications
• Anti-nausea medications if needed

In some cases, antiviral medications may be prescribed if a specific viral cause is identified and treatable.

Fungal Meningitis Treatment

Fungal meningitis is treated with long courses of high-dose antifungal medications. The specific medication and duration of treatment depend on the type of fungus causing the infection and the patient’s overall health status.

Preventing Meningitis: Vaccination and Risk Reduction

Prevention plays a crucial role in reducing the incidence of meningitis, particularly for bacterial forms of the disease. Vaccination is one of the most effective preventive measures available.

Vaccines for Meningitis Prevention

Several vaccines are available that protect against common causes of bacterial meningitis:

• Haemophilus influenzae type b (Hib) vaccine
• Pneumococcal conjugate vaccine (PCV13)
• Meningococcal vaccines (MenACWY and MenB)

These vaccines are typically included in routine childhood immunization schedules, but some may also be recommended for certain high-risk adults.

Are meningitis vaccines 100% effective in preventing the disease? While meningitis vaccines significantly reduce the risk of infection, they do not provide complete protection against all forms of meningitis. Some strains of bacteria that cause meningitis are not covered by current vaccines, and viral causes of meningitis are not preventable through vaccination.

Other Preventive Measures

In addition to vaccination, other preventive measures can help reduce the risk of meningitis:

• Practicing good hygiene, including regular handwashing
• Avoiding close contact with individuals who have meningitis
• Maintaining a healthy lifestyle to support immune function
• Seeking prompt medical attention for persistent high fever or other concerning symptoms

Long-Term Outlook and Potential Complications of Meningitis

The prognosis for individuals with meningitis can vary significantly depending on the type of meningitis, the causative agent, the timeliness of diagnosis and treatment, and individual factors such as age and overall health status.

Bacterial Meningitis Outcomes

Bacterial meningitis is the most severe form and can lead to significant complications if not treated promptly. Potential long-term effects may include:

• Hearing loss
• Vision problems
• Memory and concentration difficulties
• Balance and coordination issues
• Seizures
• Neurological deficits

What percentage of people fully recover from bacterial meningitis? With prompt and appropriate treatment, many people recover fully from bacterial meningitis. However, studies suggest that approximately 10-20% of survivors may experience long-term sequelae or complications.

Viral Meningitis Prognosis

The outlook for viral meningitis is generally more favorable. Most people recover completely without specific treatment, typically within 7-10 days. Long-term complications are rare but can occur, particularly in individuals with weakened immune systems.

Fungal and Parasitic Meningitis Outcomes

The prognosis for fungal and parasitic meningitis can vary widely depending on the specific pathogen involved and the individual’s health status. These forms of meningitis often occur in people with compromised immune systems and may require prolonged treatment.

Meningitis Research and Future Directions

Ongoing research in the field of meningitis aims to improve prevention, diagnosis, and treatment strategies. Some areas of current focus include:

• Development of more comprehensive vaccines
• Exploration of novel treatment approaches, including targeted therapies
• Improvement of rapid diagnostic techniques
• Investigation of factors influencing long-term outcomes and rehabilitation strategies

What promising advancements are on the horizon for meningitis treatment? Researchers are exploring various avenues, including the development of universal vaccines that could protect against a broader range of meningitis-causing pathogens, as well as investigating the potential of immunomodulatory therapies to mitigate the inflammatory response associated with meningitis.

As our understanding of meningitis continues to evolve, it is hoped that these research efforts will lead to improved outcomes for individuals affected by this serious condition. However, the importance of early recognition, prompt medical attention, and adherence to preventive measures remains paramount in the fight against meningitis.

Meningitis Glass Test – Meningitis Rash Test

A rash that does not fade under pressure can be a sign of meningococcal septicaemia (meningococcal bacteria can cause meningitis and septicaemia). Using the glass test on a rash that appears on someone’s skin will help you to determine whether the rash is a medical emergency or not

People with septicaemia may develop a red rash of tiny ‘pin pricks’, which can develop into purple bruising.

This rash does not fade under pressure.

The meningitis glass test

Performing the meningitis glass test is very straight forward, follow the instructions below:

• Press the side of a clear glass firmly against the skin
• Spots/rash may fade at first
• Keep checking
• Fever with spots/rash that do not fade under pressure is a medical emergency
• Do not wait for a rash. If someone is ill and getting worse, get medical help immediately

On dark skin, the spots/rash can be more difficult to see, check lighter areas such as the palms of the hands, soles of the feet, inside the eyelids and the roof of the mouth. Be aware of all meningitis signs and symptoms.

What is the rash?

The rash associated with meningitis is actually caused by septicaemia, more information below:

• Meningococcal bacteria can cause meningitis and septicaemia 
• People will often have both together
• When the bacteria are in the bloodstream, they multiply rapidly and begin to release endotoxins (poisons) from their outer coating
• The body’s natural defences have little effect on these poisons and eventually blood vessels become damaged. As septicaemia advances, it affects the whole body and can cause organ damage or failure
• The rash associated with septicaemia is caused by blood leaking into the tissues under the skin

It’s important to know that septicaemia can also cause other more specific symptoms to look out for (as well as the red rash):

• Fever with cold hands and feet
• Joint or muscle pain
• Rapid breathing
• Stomach cramps and diarrhoea

If you are worried about spotting the symptoms in time, let us help you.  Download our phone optimised videos and images on your phone, or request one of our free credit-card sized signs and symptoms cards by calling our Meningitis Helpline on 0808 80 10 388.

Concerned about meningitis?

• If you live on your own, always make sure you tell someone if you are not feeling well. They can check up on you and take action if needed
• Trust your instincts. You know your loved ones, and your own body, best
• Describe the symptoms and say you think it could be meningitis or septicaemia
• Early diagnosis can be difficult. If you have had medical advice and are still worried, get medical help again 

Do not wait for a rash. If someone is ill and getting worse, get medical help immediately.

Septicaemia and sepsis

Many medical experts now use the term sepsis instead of septicaemia. Sepsis describes the life-threatening condition that arises when the body’s response to an infection injures its own tissues and organs.

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Meningitis: Tests, symptoms, diagnosis

Meningitis occurs when the meninges, the protective coating around the brain and spinal cord, becomes inflamed. Because meningitis can be a life-threatening emergency, a person who thinks they may have meningitis should seek immediate medical care.

A meningitis test can diagnose meningitis, and help determine what caused it.

A cerebrospinal fluid (CSF) analysis can definitively diagnose meningitis. However, a doctor may recommend additional tests to rule out other causes.

If a doctor suspects bacterial meningitis, they may begin antibiotic treatment before meningitis test results come back.

Meningitis causes swelling and inflammation of the meninges. The meninges are three membranes that protect the brain and spinal cord.

Meningitis usually happens when an infection – often a virus or bacteria – travels to the meninges.

Less commonly, a fungus or parasite can cause meningitis. Bacterial meningitis can kill a person within a few hours without treatment, while viral meningitis often goes away on its own.

Very rarely, an amoeba called Naegleria fowlerican travel through water, up the nose, and into the brain. This type of meningitis is almost always fatal.

Meningitis can also occur without an infection, as a result of cancer or other diseases. Meningitis tests can tell a doctor which type of meningitis a person has, and guide treatment decisions.

This article explores the importance of seeking immediate medical attention to test for meningitis, types of tests and how doctors diagnose meningitis, meningitis causes, and the outlook for a person diagnosed with various types of the disease.

Meningitis can be a life-threatening emergency, especially if a person has bacterial meningitis. Bacterial meningitis can kill a person in a few hours.

Outcomes for viral meningitis are usually better, and a person may recover on their own without treatment.

However, it is impossible to know which type of meningitis a person has without medical testing.

Though meningitis is very serious, prompt care can save lives.

Go to the emergency room or call a doctor immediately if a person has:

• a stiff neck
• a very intense headache
• a high fever, especially following an illness such as the flu
• sensitivity to light
• an unexplained rash
• seizures
• vomiting
• confusion

There are a number of different tests a doctor can perform to diagnose meningitis, depending on which type of meningitis they think a person may have. They include:

Physical examination

Meningitis testing usually begins with a physical exam, during which a doctor assesses how likely it is that a person has meningitis. A doctor may ask about any recent illnesses, all symptoms, and when any symptoms appeared.

A doctor may also perform physical tests to assess for inflammation of the meninges. Two specific tests are often used to help diagnose meningitis.

One test looks for what is known as the Brudzinski sign. During this test, a person lies on their back while a doctor flexes their neck upward and toward the chest. If this causes the person to flex their knees or hips, this suggests inflammation of the meninges, and may mean a person has meningitis.

The other test looks for what is called the Kernig sign. During this test, a person lies on their back. A doctor bends the knee toward the chest, then attempts to straighten the leg upward. If this is very painful or impossible, a person may have swelling in the meninges, suggesting meningitis.

Blood tests and culture

Meningitis testing also generally includes blood work, which can rule out some other potential causes of meningitis, such as sepsis.

Some blood test results, such as a very high white blood cell count, may help with diagnosing a severe infection, including meningitis.

A doctor may also order bloodwork to test for other issues, such as poisoning or dangerous changes in blood glucose.

High levels of the chemical procalcitonin can also help a doctor determine whether an infection is more likely to be viral or bacterial. High procalcitonin suggests a bacterial infection.

A blood culture, which tests the blood for certain organisms, may be able to detect some types of meningitis in the blood, including some forms of bacterial and fungal meningitis. This can help guide treatment, especially when a doctor needs to know which type of antibiotic to use for bacterial meningitis.

However, a blood culture cannot definitively diagnose or rule out meningitis. According to a 2017 American Family Physician article, just 62–66% of adults under 60 with bacterial meningitis had a positive culture. Among adults over 65, the figure was slightly higher, at 73%.

Cerebrospinal fluid test

The most reliable way to diagnose meningitis is with a lumbar puncture. During a lumbar puncture, a doctor inserts a long, thin needle in between two vertebrae in the lower back. This allows them to withdraw some cerebrospinal fluid (CSF), which is the fluid that cushions the brain and spinal cord.

The doctor then sends the CSF to the lab to analyze it for signs of infection. A CSF culture can usually detect the specific organisms causing meningitis.

When a person has viral or noninfectious meningitis, there are not usually organisms in the CSF. Instead, a doctor will look for slightly elevated protein levels and elevated white blood cell counts.

Imaging tests

For some people, a lumbar puncture may not be safe. This may include those with high pressure inside the skull, certain brain diseases, a history of stroke, and those with weak immune systems because of HIV or certain drugs.

A CT scan uses x-rays to take pictures of the brain and skull. This can help with detecting whether there is any increased pressure in the head that may make a lumbar puncture unsafe. A doctor may recommend proceeding to a lumbar puncture if the CT scan indicates it would be safe.

A CT scan, however, is not a fully reliable measure of pressure in the head. A doctor may recommend foregoing both the CT scan and the lumbar puncture and beginning treatment if there are other signs of meningitis.

At-home tests

No home tests can conclusively prove that a person does or does not have meningitis. Instead, anyone with symptoms of meningitis should seek immediate medical care. Some warning signs include:

• a stiff neck
• a very intense headache
• a high fever, especially following an illness such as the flu
• sensitivity to light
• an unexplained rash
• seizures
• vomiting
• confusion

Looking for Kernig or Brudzinski signs may provide evidence that a person has meningitis. However, it is easy to perform these tests incorrectly, especially without medical training.

Many different infections and diseases can cause meningitis. They include:

• Viral meningitis: Viral meningitis happens when a virus, such as measles, mumps, or the flu, spreads to the meninges. Symptoms usually are less serious than other types of meningitis. Viruses that cause viral meningitis spread from one person to another.
• Bacterial meningitis: Bacterial meningitis happens when a bacterial infection spreads to the meninges. Many organisms can cause this infection, but some common culprits include group B streptococcus and Haemophilus influenzae. A person can spread group B strep to a newborn when giving birth vaginally. The infections that cause bacterial meningitis can spread from one person to another.
• Fungal meningitis: Fungal meningitis happens when a person contracts a fungal infection, often by inhaling spores from the environment. The infection can then spread to the meninges. Candida, a common fungal infection on the skin that can cause yeast infections or thrush, may also spread to the meninges, but this is rare.
• Parasitic meningitis: Parasitic meningitis happens when a parasite gets into the meninges. This is uncommon but can happen when a person eats raw or contaminated food, or has contact with raccoon feces from soil.
• Amebic meningitis: This rare and highly lethal type of meningitis happens when a bacteria that lives in the water travels up the nose to the meninges.
• Non-infectious meningitis: This means that the meninges become swollen without an infection. This can happen when a person has a serious disease like lupus erythematosus, a head injury, a recent brain surgery, or cancer.

The outlook depends on the type of meningitis a person has.

Bacterial meningitis has a much higher fatality rate than viral meningitis. In 2010, overall, 14.3% of people with bacterial meningitis died. Factors such as age – being either very young or very old – and having a weak immune system can increase the risk of death.

Amebic meningitis has a death rate that is much higher. Of 34 infections reported to Centers for Disease Control and Prevention (CDC) between 2009 and 2019, just 3 people survived.

Among people who do survive meningitis, complications are common, especially when meningitis damages the neurological system.

A 2010 meta-analysis of children diagnosed with meningitis found the following complication rates after hospital discharge:

• hearing loss: 6%
• behavioral issues: 2.6%
• cognitive challenges: 2.2%
• motor skill problems: 2.3%
• seizures: 1.6%
• vision impairments: 0.9%

Early testing and prompt treatment for meningitis is critical to survival.

A person who thinks they might have meningitis should not delay care, and should be clear and specific at the emergency room about what symptoms they are experiencing.

A person should tell a doctor about any recent potential meningitis exposures, and request testing for meningitis immediately.

How to recognize meningitis and diagnose the disease in the Optimum medical laboratory in Sochi (Adler)

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Symptoms, diagnosis and prevention of meningitis

Meningitis is an inflammation of the membranes of the brain or spinal cord, which can be triggered by infections of viral and bacterial etiology. Pathology is accompanied by a severe headache, a typical body position in bed, hemorrhagic rashes on the skin and stiffness of the muscles of the occipital zone. Children and adolescents, as well as elderly people with weakened immune systems, are especially susceptible to this disease.

Causes of meningitis

The main cause of meningitis are infections of viral and bacterial etiology. The causative agent of the inflammatory process can be:

• pneumococci;
• Haemophilus influenzae;
• Escherichia coli;
• streptococci;
• amoeba.

In childhood, the main cause of the development of pathology is enteroviruses that enter the body by airborne droplets. Infection can occur during childbirth, through contaminated food, dirty water, and insect bites. The main causes of non-infectious meningitis are trauma and damage to the skull, as well as tumor processes occurring in the brain.

Mechanism of development

For the development of pathology, the pathogen must penetrate the cranial cavity and provoke an inflammatory process in the brain. In some cases, this is observed when foci of infection occur in tissues located near the meninges. Pathologies such as purulent otitis media or sinusitis can provoke meningitis.

In some cases, craniocerebral trauma becomes a provoking factor in the development of pathology, but the infection mainly penetrates into the cranial cavity along with the blood flow. The very process of entering the pathogen into the blood and its further spread to the meninges is associated with a poor state of immunity.

Symptoms

Meningitis causes the following clinical picture:

• rise in body temperature;
• photophobia;
• muscle tension in the occipital region;
• confusion;
• convulsive syndrome;
• strabismus;
• muscle pain syndrome;
• mental disorders;
• tachycardia;
• rashes on the skin.

If these symptoms develop, seek medical attention as soon as possible because meningitis has a high mortality rate.

Diagnostic methods

The main method for diagnosing meningitis is lumbar puncture with further examination of cerebrospinal fluid. This diagnostic method is used in all cases when there is a suspicion of a disease.

In addition, the doctor analyzes the patient’s complaints and collects an anamnesis, as well as conducts a neurological examination. With the help of a blood test, it is possible to diagnose signs of inflammation, and PCR of blood and cerebrospinal fluid helps to identify the pathogen.

Computed and magnetic resonance imaging allows to assess the structure of the brain and diagnose indirect manifestations of the pathological process in the meninges of the brain.

Prevention

Some forms of meningitis can be prevented by vaccination, which is effective for several years. As a preventive measure, it is recommended to treat chronic and acute pathologies of an infectious nature in a timely manner and take courses of immunostimulating drugs in the foci of meningococcal disease. In addition, you should harden the body, avoid visiting places with large crowds of people and severe hypothermia. In the autumn-winter period, you need to drink multivitamin complexes or vitamin C.

Tests for meningococcal infection

The causative agent of meningococcal infection is Neisseria meningitidis (meningococcus). Meningococcus colonizes the posterior wall of the human nasopharynx and, depending on the virulence of the strain and the resistance of the infected person, causes an infectious process with a wide range of clinical manifestations: asymptomatic carriage, nasopharyngitis and a generalized form – meningococcemia and / or meningitis. Meningococcal infection affects people of all ages, but more often (70%) children get sick. The lethality rate averages 10%, which determines the high social significance of the disease. Capsular strains of meningococcus, depending on the chemical structure of the capsular polysaccharide, are divided into a number of serological groups: A, B, C, X, Y, Z, W-135, 29-E, H, I, K, L. More than 90% of cases of generalized forms of meningococcal infection are caused by strains of serogroups A, B and C, much less often by strains of serogroups X, Y and W-135, the remaining serogroups are not of epidemiological interest. The determination of the serogroup is the most important procedure for the selection of an adequate vaccine product. All meningococci express on their surface one of the allelic variants of class 2 or 3 outer membrane proteins (PorB). Most meningococci express class 1 proteins (PorA). The antigenic structure of the PorB protein determines the serotype of the strain, while the PorA protein determines the serosubtype. Based on the chemical structure of the capsular lipopolysaccharide, the immunotype is determined. The antigenic characteristic may include some other AGs: Ora and Ors (class 5 outer membrane proteins), pili, FetA surface protein.

Indications for examination

• Diagnostic studies are carried out in a hospital with suspected purulent meningitis and / or a generalized form of meningococcal infection;
• studies according to epidemic indications are carried out in the focus of a generalized form of meningococcal infection among those who have been in contact with the patient and have clinical manifestations of nasopharyngitis.

Study material

• Blood – microscopic examination, culture;
• CSF – microscopic examination, culture, DNA detection, AH detection;
• swabs from the oropharynx and nose – culture;
• blood serum – detection of hypertension, determination of specific antibodies

Differential diagnosis

• Causative agents of purulent meningitis of other etiologies: Streptococcus pneumonia, Haemophilus influenza, Staphylococcus aureus, etc.;
• in the study of the nasopharynx – pigmenting Neisseria subflava, Neisseria flavescens, Neisseria mucosa, Neisseria sicca, Neisseria lactamica.

Laboratory diagnosis of a generalized form of meningococcal infection includes microscopy of biological material, inoculation of biological material with further cultural and biochemical identification of the pathogen, determination of antibiotic sensitivity; detection of specific genetic fragments of meningococcus and its AG, detection of specific antibodies.

Comparative characteristics of laboratory research methods and features of interpretation of their results. Microscopy of native cerebrospinal fluid or a “thick drop” blood product (stained with an aqueous-alcoholic solution of methylene blue) on a blue background reveals morphologically clear cocci, diplococci, stained in dark blue, resembling coffee beans or bean seeds, adjacent to each other with concave sides , sometimes the capsule comes to light. Microbial cells can be located both outside and inside leukocytes. The intensity of CSF contamination by microbial cells varies considerably and depends on the stage of development of the infectious process at the time of sampling. If antibiotic treatment has been carried out, the typical microbial cell morphology is lost. The study is recommended to be carried out in the active phase of the disease (the first two days after admission to the hospital).

Inoculation of CSF and blood on nutrient media with further incubation for 24 hours at 37°C in an atmosphere with 5–10% CO2 and high humidity makes it possible to identify the characteristic tinctorial properties of the pathogen. The study is recommended to be carried out in the active phase of the disease (the first two days after admission to the hospital) before the start of intensive antibiotic therapy.

When determining the saccharolytic activity, the results of sowing a pure culture on dense nutrient media with carbohydrates are taken into account. The method makes it possible to differentiate different types of Neisseria and some other types of microorganisms (Table 16). Sometimes there is variability in saccharolytic activity in different strains of the same species.

Clarification of the biochemical properties of meningococci is carried out using reagent kits for an extended study of their enzymatic and metabolic activity, which within 2 hours allows you to determine the species of the pathogen.

The determination of the serogroup of meningococci is carried out in the agglutination reaction on glass with a set of agglutinating serogroup antisera (serogroups A, B, C, X, Y, Z, W-135,29E). The reaction is carried out only with a pure culture of meningococci that has passed all stages of identification. Meningococci of serogroups A, B and C are most often the cause of generalized forms of meningococcal infection, the agglutination reaction is carried out primarily with antisera to meningococci of these serogroups. The absence of a reaction with one of the main serogroup antibodies indicates the need to continue similar studies with other specific antisera (X, Y, Z, W-135, 29e). Only if a strain of meningococcus confirmed by all tests did not show a positive result in the agglutination test with a full set of agglutinating antisera, it should be classified as a non-agglutinating strain (NA).

Latex agglutination reaction is used to detect AG in CSF and/or blood serum. The study of native cerebrospinal fluid (express method) is carried out if it contains signs of purulent inflammation and / or microscopic detection of pathogens. The use of the reaction allows in the shortest possible time (15-20 minutes) to identify specific AG of meningococci of the most common serogroups (A, B, C, Y, W-135). It is recommended to conduct a study in the active phase of the disease (the first two days after admission to the hospital).

CSF and/or a fresh pure culture of Neisseria meningitidis grown on Petri dishes is used to detect pathogen DNA. Detection of specific genetic fragments of the microorganism is performed using PCR. The method has high diagnostic sensitivity and specificity, allows to detect microorganisms contained in single quantities or in a non-viable state in a clinical sample, is characterized by high reproducibility and short deadlines for performing the study (within several hours).

Indications for conducting studies to detect DNA in the diagnosis of bacterial meningitis are:

• negative results of diagnosis by other methods, especially in the case of examination of CSF samples after massive antibiotic therapy or in the late stages of the disease;
• the need for an urgent response about the etiology of the pathogen;
• Examination of material samples delivered frozen or fixed in ethanol.

Detection of specific antibodies in the blood serum in the diagnosis of meningococcal infection is carried out using RNHA. It is recommended to conduct the study twice: in the active phase of the disease (the first two days after admission to the hospital) and on the 12-14th day of the disease. The diagnosis is considered confirmed when the increase in titers of antibodies by four or more times within the specified period.

The use of RNHA for research in “paired sera” reveals the dynamics of the increase in titers of specific antibodies to meningococcus in the blood and allows you to determine whether the pathogen belongs to the most common serogroups of meningococci (A and C). The detection of AT makes it possible to conduct a retrospective laboratory diagnosis of generalized forms of meningococcal infection, since the final answer is obtained only 12-14 days after the onset of the disease. The primary research opportunities are laboratory confirmation of meningococcemia, in which the use of other methods of laboratory diagnostics, as a rule, is not very effective.