Meningitis is a rare but potentially fatal infection in children that can leave permanent sequelae. The most common bacteria causing meningitis in children are Haemophilus influenzae type B (Hib), pneumococcus, and meningococcus; vaccines are available for the first two and are administered routinely to infants starting from the 2nd month. The vaccine for meningococcal disease was first introduced worldwide in 2006 and has been used in our country since 2013.
The Global Situation of Meningococcal Infections
Meningococcal infections are seen all over the world, but they are more common in temperate regions such as Africa and the Arabian Peninsula. In our country, the incidence is around 2-4 per 100,000. Meningococcus has serotypes such as A, B, C, Y, and W-135, and the detected types vary by country. Epidemiological studies conducted in our country have shown that W-135 and type B are the most common.
Every year, 1,200,000 meningococcal disease cases are reported worldwide, and 135,000 of these result in death.
Who are the risk groups for meningitis?
Meningococcal infections are especially seen in children under 5 years of age and make a second peak during adolescence (15-25 years). The transmission rate is particularly high in crowded environments such as military barracks and dormitories. People going on pilgrimage (Hajj) and those traveling to endemic regions such as Africa are also at risk. These individuals are also vaccinated for protection before travel.
Not everyone who encounters the meningococcal bacteria develops the disease; about 5-10% may carry this bacteria in their throat without becoming ill. Especially people with weak immune systems and those whose spleen has been removed are at risk.
How does meningococcus cause disease?
Meningitis is common in winter and spring months. The bacteria enter the body through the respiratory tract and usually begin like a respiratory tract infection. When the microbe reaches the blood and the membranes of the brain, sepsis and meningitis develop. Headache, high fever, vomiting, and confusion are signs of meningitis. A condition called meningococcemia, characterized by subcutaneous bleeding throughout the body, progresses within hours and causes shock and organ failure. 10-20% of cases result in death despite treatment. Survivors may have sequelae such as tissue loss in the hands and feet, seizures, deafness, and intellectual disability.
Preventive treatment is applied to the patient’s close contacts and those who have been exposed.
Meningitis Vaccine
Meningococcus has been included by the World Health Organization among vaccine-preventable diseases, and the developed vaccine has been shown to be effective and safe. Currently, vaccines covering 4 types of meningococcus are available and are used in more than 50 countries worldwide.
The meningitis vaccine is administered to babies older than 9 months. There are currently 2 vaccines used in our country. Menactra is recommended as 2 doses 3 months apart between 9-23 months, and after the age of 2 it is given as a single dose and can be administered up to the age of 55. Nimenrix is given as a single dose after the age of 1. New vaccine studies are ongoing.
Are there side effects of the meningitis vaccine?
The most common side effect of the vaccine is redness and tenderness at the injection site. In general, side effects such as fever and restlessness may occur. Rarely, the vaccine should not be administered to those who are allergic to the substances in the vaccine.
Dr. Hale Yener / Pediatric Health and Diseases Specialist / İRENBE