October 5th is World Meningitis Day. There are many pathogens that cause meningitis, with common ones including epidemic cerebrospinal meningitis, Japanese encephalitis, tuberculosis, Streptococcus pneumoniae, Haemophilus influenzae type B, enteroviruses, herpesviruses, Salmonella, and Cryptococcus, among others. The most fundamental method of prevention is vaccination, making it extremely important to vaccinate children. Paediatrician Dr. Lam Ka-yee shares more information on childhood meningitis.
Q1: What is meningitis? What circumstances can trigger meningitis?
Meningitis refers to inflammation of the meninges, the membranes that surround the brain and spinal cord, which is usually caused by an infection.
Q2: Is Hong Kong a high-risk area for meningitis? Are there any particular places that are high-risk?
Hong Kong is not a high-risk area for meningitis; according to the WHO, sub-Saharan Africa is a high-risk area.
Q3: Is meningitis classified?
Meningitis is generally divided into viral and bacterial types, with fungal meningitis being relatively rare.
Which bacteria are the most dangerous and most likely to cause meningitis?
The more common bacteria causing meningitis include: *Neisseria meningitidis*, *Streptococcus pneumoniae*, *Haemophilus influenzae* type b, and *Streptococcus agalactiae*; while viruses include: influenza viruses, enteroviruses, Japanese encephalitis virus, and herpesviruses.
What are the symptoms in young children and infants once infected?
In young children, the illness can worsen rapidly within a short period. Symptoms depend on the bacteria or virus causing the meningitis, and initial symptoms may not be obvious, including: fever, upper respiratory tract infection symptoms, and rash. Subsequently, symptoms like headache, vomiting, drowsiness, neck stiffness or seizures, and even shock may appear.
When do inflammatory reactions in a child require urgent medical attention?
If a young child has a high fever and develops a rash, vomiting, loss of appetite, or lethargy, seek medical attention as soon as possible. If convulsions occur, you must go to the emergency department.
Q7: What is the difference between meningitis in young children and adults?
The symptoms of meningitis in young children are largely the same as in adults, but because the condition can rapidly deteriorate in toddlers and they may not be able to express themselves clearly, it is easy to miss the opportunity for early treatment.
Q8: How long is the incubation period for meningitis? Is it contagious? What are the transmission routes?
The incubation period depends on the bacteria or virus. For typical bacterial meningitis, such as meningococcal meningitis, the incubation period is 2 to 10 days. For viral meningitis, such as influenza, the incubation period is generally 1 to 4 days, and for enterovirus, the incubation period is 3 to 5 days.
Viral and bacterial meningitis can be transmitted through contact and droplet.
Meningitis is often confused with which diseases?
As the early symptoms of meningitis are not obvious, it is generally easily confused with common bacterial or viral infections; some young children who develop a high fever are prone to febrile seizures, and the symptoms are also similar to those of meningitis.
Q10: How is meningitis diagnosed? Is a lumbar puncture performed to obtain cerebrospinal fluid for culture?
If there are suspected cases, a lumbar puncture will be arranged to collect cerebrospinal fluid for examination to determine if there is a meningitis infection.
Q11: Is a lumbar puncture risky for children? Are there any long-term side effects?
A lumbar puncture is an invasive diagnostic procedure, and potential complications such as bleeding, headaches, infection, and a sudden drop in intracranial pressure leading to brain herniation can occur, though these risks are not common.
How is meningitis treated?
Treatment for meningitis includes supportive care and targeted therapy. Supportive care involves stabilising the patient's blood pressure, respiration, oxygen saturation, heart rate, and other vital signs. Targeted therapy generally addresses the bacteria or virus causing the infection. Antibiotics are used to treat bacterial meningitis, while for viral meningitis, most antiviral treatments are not particularly effective, and some have no specific treatment.
Q13: How long does it generally take for a child to fully recover after treatment?
If treated early, some cases of meningitis in young children can be completely cured after two to three weeks of treatment. However, most cases have the potential for complications. A child's vision, hearing, and intellect may be impaired due to the meningitis infection. Some patients infected with meningococcal meningitis may require amputation.
Q14: If someone has had meningitis, are they more likely to get infected again? Or does the body have antibodies that make it difficult to get infected?
Patients with meningitis produce antibodies to newly infected bacteria or viruses, which are maintained for a period of time. However, due to a general decline in their overall condition, they are also relatively more susceptible to other viral and bacterial infections, and severe infections can lead to meningitis.
Q15: What are the methods to prevent meningitis? Are there vaccines that offer comprehensive protection? Or how many vaccines are sufficient to adequately protect children?
The most effective ways to prevent meningitis include paying attention to and maintaining personal and environmental hygiene, keeping hands clean, washing hands frequently, cleaning homes and toys with household bleach diluted 1:99, avoiding infection, and getting vaccinated. The Department of Health's vaccination programme already includes the pneumococcal vaccine. Parents may consider additional vaccinations for young children, such as the Haemophilus influenzae type b vaccine, meningococcal vaccine, Japanese encephalitis vaccine, and annual flu vaccination, to reduce the chance of severe complications from infection.
Case Study
In the past, there have been cases of children who developed meningitis due to infections such as influenza, Haemophilus influenzae type b, and enteroviruses. Although these cases were not life-threatening, they resulted in damage to hearing, intellect, and self-care abilities, causing significant impact and a heavy burden on the future of the children and their families.
Source: Learn Well - GoStudy.HK (5 October 2023)
