Overview of Neisseria meningitidis
Neisseria meningitidis is an acute suppurative meningitis that can be characterized by sudden onset of high fever, severe headache, frequent vomiting, flaky subcutaneous hemorrhages on the skin and mucous membranes, etc. The prognosis for the common type is good, while the morbidity and mortality rate of the fulminant type is high, which requires early and active application of antimicrobial drugs and symptomatic treatment.
Definition
Epidemic cerebrospinal meningitis (ECM), abbreviated as epidemic cerebrospinal meningitis (ECM), is an acute suppurative meningitis caused by Neisseria meningitidis infection.
The main clinical manifestations of epidemic encephalitis are sudden onset of high fever, severe headache, frequent vomiting, dotted subcutaneous hemorrhagic spots on the skin and mucous membranes, etc. In severe cases, there may be shock and parenchymal damage to the brain, which is often life-threatening [1-4].
Types
According to the condition, the disease can be divided into the following four types [4].
Common type
The common type accounts for about 90% of the cases, and according to its developmental process, it can be divided into four stages: prodromal stage (upper respiratory tract infection stage), sepsis stage, meningitis stage, and recovery stage, but there is no obvious boundary between the clinical stages.
Sudden onset
A small number of patients have a rapid onset of disease, the condition is dangerous, if not rescued in time, often within 24 hours of life-threatening.
Mild
Mostly seen in the late stage of epidemic, with mild clinical manifestations, headache, low fever, sore throat and other upper respiratory tract symptoms, and a few hemorrhages on the skin.
Chronic sepsis type
This type is less common, mostly seen in patients with incomplete immunodeficiency or other chronic diseases, and is more common in adult patients.
Morbidity
Influenza can occur throughout the year, but there is obvious seasonality, mostly occurring in winter and spring, with March-April as the peak of incidence.
The disease is prevalent or distributed in countries all over the world, with an average annual incidence rate of about 25,000 per 100,000 people.
In China, there have been 5 national epidemic of epidemic. However, after the large-scale vaccination of group A of epidemic encephalitis was carried out in 1985, the incidence of epidemic encephalitis in China has continued to decline, and no national pandemic has occurred again [2].
Causes
Causes
The disease is caused by Neisseria meningitidis infection, and the basic conditions leading to epidemics are threefold.
Source of infection
Carriers and patients with meningitis are the main sources of infection of the disease.
Route of transmission
The disease is transmitted directly from the respiratory tract mainly through coughing and sneezing with droplets.
Because the pathogenic bacteria have very weak vitality outside the body, it is seldom transmitted indirectly through daily necessities, but close contact such as co-sleeping and breastfeeding is important for the development of infants and young children under 2 years old.
Susceptible population
The population is generally susceptible and has a high rate of latent infection. After infection, the bacteria can parasitize the nasopharynx of normal people, and it is not easy to be detected when asymptomatic.
Pathogenesis
Neisseria meningitidis can invade the human body from the nasopharynx, if the human body has strong immunity, it can kill the pathogenic bacteria quickly, or become a carrier state; if the body lacks specific bactericidal antibodies, or the bacterial virulence is strong, the bacterium can enter the bloodstream from the mucous membrane of the nasopharynx, develop into sepsis, and then involve the cerebrospinal membrane, forming purulent cerebrospinal meningitis.
The invasion of bacteria from the nasopharynx into the cerebrospinal meninges occurs in three steps, i.e., the bacteria adheres to and passes through the mucous membrane, the bacteria enters into the blood stream, and finally invades the meninges.
Symptoms
Main Symptoms
The disease can be categorized into four types, with symptoms varying between the different types [4-7].
Common type
Patients with the common type can be categorized into the following four phases according to the course of the disease, but the phases are not easily and strictly separated from each other clinically.
Prodromal stage (upper respiratory tract infection stage)
Symptoms such as low-grade fever, sore throat, nasal congestion, and cough may be present.
Septicemia
There may be chills (fear of cold), high fever, body temperature can be up to 40 ℃ or more, accompanied by headache, vomiting, fatigue, muscle pain, indifference and so on.
About 70% of patients may also have skin and mucous membrane punctate, flaky subcutaneous hemorrhages, i.e. petechiae, ecchymoses, commonly found on the limbs, conjunctiva, buttocks, etc.
Meningitis stage
Most of them appear simultaneously with the symptoms of sepsis stage, mainly manifested by severe headache, frequent vomiting, vomiting may be jet, there may be irritability, and meningeal irritation signs, such as positive cervical tonus examination.
Recovery period
After treatment, the patient’s body temperature may gradually decrease to normal, consciousness and mental state improve, skin petechiae (spots) absorb or scab healing, and neurological examination returns to normal.
Sudden onset
The condition of patients with fulminant type is very dangerous and progresses rapidly, which can be life-threatening if not treated in time.
Shock type
Most of the patients have rapid onset of the disease, may have chills, high fever, and in severe cases, the body temperature may not be elevated, accompanied by headache, vomiting, and within a short time, there may be subcutaneous hemorrhagic dots all over the body, which may rapidly increase and merge into patches.
Circulatory failure may occur in this type, with pale face, cold limbs, purple (cyanosis) of lips and fingertips, significant drop in blood pressure or even inability to measure, and decreased or absent urine output.
Meningoencephalitis type
The main manifestation is damage to the meninges and brain parenchyma, in addition to symptoms of high fever, headache and vomiting, the patient may rapidly fall into coma, accompanied by frequent convulsions, and there may be a sustained increase in blood pressure.
Some patients of this type may have brain herniation, which is characterized by unequal pupil size bilaterally, dull or absent reaction to light, irregular respiration with different speeds and depths or respiratory arrest, and increased muscle tone of limbs.
Mixed type
It has the clinical manifestations of both shock type and meningoencephalitis type. This type is the most dangerous, with poor prognosis and high mortality rate.
Mild type
In this type, the lesions are mild, and the clinical manifestations may only include low-grade fever, mild headache, sore throat, etc. There may be a few tiny bleeding spots on the skin and mucous membrane, and there is no consciousness disorder.
Chronic sepsis
The course of the disease often extends for several months, and may be characterized by intermittent chills, chills, fever, rash, arthralgia and general weakness.
Complications
Complications of the disease mainly include secondary infection, septic lesions caused by spreading to other organs during sepsis.
Secondary infections
Pneumonia is the most common secondary infection, which may be characterized by cough and sputum, and is most common in the elderly and infants.
Other secondary infections include pressure sores and urinary tract infections, which may cause frequent, urgent and painful urination.
Purulent migratory lesions
Otitis media: sudden onset of severe pain deep in the ear, which may be distending or stabbing, accompanied by a feeling of ear stuffiness, and may be accompanied by mild hearing loss.
Septic arthritis: acute onset, with symptoms such as chills and high fever, body temperature up to 39 ℃ or more, and even blurred consciousness and coma.
Septic thorax: there are signs of high fever, rapid pulse rate, shortness of breath, chest pain, generalized fatigue, and elevated white blood cells. Those with more pus accumulation also have symptoms of chest tightness, cough and sputum.
Consultation
Department of Medicine
Department of Infectious Diseases
If symptoms such as fever, sore throat, headache, vomiting, or subcutaneous hemorrhages occur during an epidemic or epidemic, it is recommended that you consult the Department of Infectious Diseases.
Neurology
Neurology is also recommended for sudden onset of high fever, severe headache, and frequent vomiting.
Emergency Medicine
In case of drowsiness, blurred consciousness, low blood pressure, shock, coma, etc., it is recommended to consult the Department of Emergency Medicine immediately.
Preparation
Preparing for your visit: registering, preparing documents, and common problems.
Tips for seeking medical treatment
This disease is contagious, it is recommended to wear a mask and avoid public transportation.
If you have fever, record the change of body temperature for the doctor’s reference.
If there is vomiting, take photos of the vomit for the doctor’s reference.
If there are bleeding spots on the skin, record the time of appearance and take photos for the doctor’s reference.
Preparation Checklist for Doctor’s Visit
Symptom Checklist
Pay particular attention to the time of onset of symptoms, special manifestations, etc.
Is there fever and what is the highest temperature?
Is there fatigue, sore throat, headache, muscle pain?
Is there nausea or vomiting? Is the vomiting of a projectile nature?
Are there any bleeding spots on the skin?
How long have the above symptoms lasted?
List of medical history
Has there been any contact with a person with epidemic cerebrospinal meningitis?
Have you traveled to an area where epidemic cerebrospinal meningitis is endemic?
Checklist
Test results in the last 1 month, which can be brought to the doctor’s office
Laboratory tests: routine blood test, cerebrospinal fluid test, etc.
Bacteriologic examination: bacterial smear, bacterial culture.
Medication list
Medication used in the last 1 month, if available, bring the box or package for medical consultation
Anti-infective drugs: penicillin, chloramphenicol, cephalosporin, etc.
Diagnosis
Diagnosis based on
Medical history
Patients often have a history of residence or travel in areas where epidemic cerebrospinal meningitis is endemic within 10 days prior to onset of illness.
Clinical manifestations
The manifestations vary among the various types of epidemic encephalitis. In general, patients with mild disease may have non-specific symptoms of upper respiratory tract infection, such as low-grade fever, sore throat, cough, and malaise. Severe patients may have different degrees of impaired consciousness (e.g. drowsiness, coma), shock, etc. Typical patients may have sudden onset of high fever.
Typical patients may have sudden onset of high fever, severe headache, frequent vomiting, and punctate subcutaneous hemorrhagic spots on the skin and mucosa.
Laboratory Tests
Routine blood tests
The total number of white blood cells and neutrophil count may be significantly elevated. Leukocytes may reach (10-30) × 109/L or more, and neutrophils are markedly elevated.
Cerebrospinal fluid examination
Cerebrospinal fluid examination is an important method to confirm the diagnosis.
Typical meningitis stage, there may be elevated cerebrospinal fluid pressure, the appearance of the cerebrospinal fluid is still clear, later turbid like rice soup or pus; white blood cell count often up to 1000 × 106 / L, mainly neutrophils; protein content is significantly increased; sugar and chloride significantly reduced.
Bacteriologic examination
Bacterial smear examination
Including skin petechiae and cerebrospinal fluid after centrifugal precipitation for smear staining.
Petechial smear is simple and easy to perform, and is an important method for early diagnosis.
Bacterial culture
Cerebrospinal fluid, blood, and petechial tissue fluid are taken for culture. If Neisseria meningitidis grows, drug sensitivity test should be done at the same time to guide the use of drugs.
Immunologic examination
Positive detection of Neisseria meningitidis-specific polysaccharide antigen in cerebrospinal fluid may be present in the acute phase.
In the recovery phase, there may be a 4-fold or more than 4-fold increase in serum Neisseria meningitidis-specific IgG antibody test potency compared with the acute phase, which is of diagnostic significance.
Diagnostic criteria
Epidemic cerebrospinal meningitis can be categorized into suspected cases, clinically diagnosed cases and confirmed cases [4].
Suspected cases
Suspected cases have the following characteristics.
Epidemiologic history of cerebrospinal meningitis: onset of the disease in winter and spring, history of close contact with patients with cerebrospinal meningitis within 1 week, or local occurrence or prevalence of the disease; no previous vaccination against cerebrospinal meningitis.
Clinical manifestations and cerebrospinal fluid examination are consistent with the manifestations of purulent meningitis.
Clinical diagnosis
Clinically diagnosed cases have the following characteristics.
Epidemiologic history of meningitis.
Clinical manifestations and cerebrospinal fluid examination are consistent with purulent meningitis manifestations and are accompanied by petechiae and ecchymosis of the skin and mucous membranes. Or, although there is no purulent meningitis, there are rapidly increasing skin and mucous membrane petechiae and ecchymosis in conjunction with post-infectious toxic shock.
Confirmed cases
On the basis of clinically diagnosed cases, positive bacteriologic examination and immunologic examination of rheumatoid-specific serum.
Differential diagnosis
Epidemic cerebrospinal meningitis needs to be differentiated from pyogenic meningitis and tuberculous meningitis caused by other bacteria.
Septic meningitis caused by other bacteria
Septic meningitis due to other bacteria is caused by bacteria that can cause suppurative infections, such as staphylococci, etc. Its onset is not seasonal, and it can be differentiated by the presence of a primary lesion and the absence of skin petechiae.
Tuberculous meningitis
Tuberculous meningitis is caused by Mycobacterium tuberculosis infection with a history of tuberculosis and an unseasonal onset. It is characterized by a long course of disease, low-grade fever, night sweats, emaciation, etc., and the absence of skin petechiae.
Treatment
Aim of treatment: to relieve symptoms, control the development of the disease and reduce complications.
Treatment principle: early application of antibacterial drugs and symptomatic treatment.
Ordinary Influenza
General treatment
Early diagnosis, hospitalization and isolation after diagnosis, close monitoring of vital signs.
Patients need to rest in bed, keep the room quiet and air circulation.
Keep the mouth and skin clean and change the position frequently to prevent bedsores.
For patients with high fever, physical cooling can be performed.
Symptomatic treatment
Patients with high fever can be physically cooled down and apply antipyretic drugs, such as ibuprofen, as appropriate.
Patients with intracranial hypertension can be treated with 20% mannitol dehydration.
Adrenocorticotropic hormone, such as hydrocortisone, can be applied to patients with severe toxemia and intracranial hypertension.
Pathogenetic treatment
When there is a high suspicion of rheumatoid encephalitis, antimicrobials should be administered as soon as possible and in adequate doses.
Penicillin G
Neisseria meningitidis is highly susceptible to penicillin and is particularly effective in treating patients with septicemic forms of the disease.
Be aware of allergic reactions such as skin rashes and asthma attacks during administration.
Cephalosporins
Third-generation cephalosporins such as cefotaxime have strong antibacterial activity against meningococcus with low toxicity.
They can be used as the first choice of drugs other than penicillin.
Chloramphenicol
Chloramphenicol has good antibacterial activity and is effective in the treatment of meningitis and other purulent meningitis.
Chloramphenicol has large adverse reactions, especially on the bone marrow hematopoietic function has inhibition, and even can cause aplastic anemia, so the selection should be very careful, generally not as the first choice, newborns should not be used.
Sulfonamide
Sulfadiazine (SD) or sulfamethoxazole (SMZ), which are more stable and not easy to deteriorate, are not used or less used due to the increase of drug-resistant strains of bacteria.
The practical application of sulfonamides is limited because of their poor efficacy in sepsis, difficulty in oral administration when high intracranial pressure leads to vomiting in the acute stage, and the possibility of precipitation and stone formation in the ureter.
Meningococcal influenza
In addition to early treatment with antimicrobial drugs, the following principles should be followed in the treatment of fulminant rheumatic encephalitis.
Shock type
Rapid correction of shock with crystalloid and colloid fluids as appropriate.
Early application of heparin is appropriate when disseminated intravascular coagulation is highly suspected.
Adrenocorticotropic hormone can be added as appropriate in patients with obvious symptoms of toxemia.
Attention should be paid to protect the function of important organs, such as brain, heart, liver, kidney and lung function.
Meningoencephalitis
Early detection of cerebral edema, active dehydration treatment, prevention of cerebral hernia, and in the treatment at the same time pay attention to keep the airway open, if necessary, tracheal intubation, the use of ventilator treatment.
Mixed type
The treatment of cerebral edema needs to be taken into account while actively treating shock.
Prognosis
Cure
If the common type is diagnosed in time and treated reasonably, the prognosis is good, and complications and sequelae are rare.
The morbidity and mortality rate of the fulminant form is higher, and the prognosis of the meningoencephalitis and mixed forms is poorer.
Hazards
Patients with Meningococcal Encephalitis may suffer from severe headache, frequent vomiting, irritability, etc., which affects the normal life of the patients, and there is a risk of death in severe cases.
Patients with this disease may be left with sequelae such as paralysis, epilepsy and mental disorders, and may need further rehabilitation, limb function exercise and psychotherapy in later stages.
Daily
Daily Management
Dietary management
Ensure adequate daily water intake, eat small and frequent meals daily, ensure nutritional supply, and actively supplement high-quality protein, such as dairy products and lean meat.
Life management
Pay attention to more rest, keep the room quiet and air circulation.
When resting in bed, change the position frequently to prevent pressure sores; keep the mouth clean and skin clean to prevent skin ulcers.
Do a good job of environmental and personal hygiene during the influenza epidemic period. Indoors can be fumigated with vinegar and mugwort leaves.
In areas where influenza is prevalent, try to avoid crowded and poorly ventilated public places, and wear a mask when going out to prevent infection.
Prevention
Prevention of the disease can be carried out through the following aspects [4,8-10].
Management of infectious agents
Early detection of patients and respiratory isolation and treatment, should be isolated until 3 days after the disappearance of symptoms, usually not less than 7 days after the disease, at the same time, their contacts for medical observation for 7 days.
Cut off the way of transmission
Do not spit, and cover your nose and mouth with tissue paper when sneezing or coughing.
Pay attention to hand hygiene, wash hands frequently, use soap and wash hands with running water.
Pay attention to the cleanliness of the living environment, open windows and keep the air circulating.
Protecting susceptible people
Vaccination
At present, there are two main types of influenza vaccines, namely, group A influenza vaccine and group A+C influenza vaccine. group A influenza vaccine can prevent group A influenza with a protection rate of more than 90%, and group A+C influenza vaccine can prevent the onset of both group A and C influenza.
Drug prevention
Drug prophylaxis can be given to close contacts, especially susceptible, frail and carriers. Drugs are best selected according to the prevalent flora and drug sensitivity in the area, such as sulfadiazine.