Bacterial Meningitis
Meningitis is an infection of the meninges of the brain and the spinal cord and when this infection is caused by bacteria, it is called bacterial meningitis.
OCCURENCE
Common bacterial strains that are the cause of infection of the meninges involves
Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis.
Bacterial Meningitis
Group B Streptococcus, Escherichia coli, and Listeria monocytogenes are the most common causes of meningitis in neonatals. In the United States, about 17,500 cases of bacterial meningitis are reported annually.
In America, before 1990, the highest cause of bacterial infection of the meninges was due to the bacterial strain Haemophilus type b. The introduction of Hib vaccine in the child immunization schedule has shown a drastic decrease in the incidence of bacterial meningitis caused by this bacteria.
The occurrence of bacterial meningitis is noticed in all age groups but seems to be common in infants and young children. It is also common in elderly people who are mostly above the age of 60. Children who miss the routine vaccinations of the immunization schedule given by WHO, are more at a risk of getting the infection.
MODE OF INFECTION:
Many of the bacteria that cause meningitis are reasonably well-known and are more often associated with other common infections. The mode of spread of infection is basically from the bacterial infection in the skin, digestive tract, urinary system or respiratory tract. The spread of infection in a large number of cases is mainly from the respiratory infections since these bacteria are able to enter the blood stream, thus infecting the meninges of the brain and the cerebrospinal fluid. In a few infections such as ear infection or sinusitis or infection from injuries in the brain, the bacteria can rapidly infect the meninges.
SPREAD OF INFECTION
The infection can spread by direct contact with the discharges from the nose or throat or urine of an infected person. Children who stay in groups like in boarding schools, dormitories and military recruits are more prone to infections, predominantly because infectious diseases tend to spread quickly within closely packed and large groups of people.
SIGNS AND SYMPTOMS The onset is usually abrupt with fever, headache and vomiting. In some cases, these symptoms may take 48 hours to develop. The patient does not wants to turn on his back because of spinal irritation. Marked stiffness of neck is seen due to spasm of cervical muscles. A rash is seen in about 40% of the patients which appears on the 2nd or 3rd day after infection.
In neonatals and infants, the typical symptoms of fever, headache and neck stiffness may be difficult to detect. The first sign of the illness is repeated convulsions. Other signs in babies might be inactivity, irritability, projectile vomiting and poor feeding.
DIAGNOSIS OF BACTERIAL MENINGITIS
The diagnosis is usually made by taking a sample of the cerebo-spinal fluid and testing it for WBC count, glucose levels and protein values, a Gram stain and culture. to identify the particular strain.
VACCINATIONS AGAINST BACTERIAL MENINGITIS
Vaccines against N. meningitidis available in the U.S. The most prevalent ones are :
1) Meningococcal polysaccharide vaccine which has been approved by the Food and Drug Administration (FDA) and
2) Meningococcal conjugate vaccine
The vaccine against Neisseria meningitidis (meningococcal vaccine) is not routinely used on civilians in the U.S. The vaccine is sometimes used to control outbreaks of some types of meningococcal meningitis. The vaccines against Hib are very safe and remarkably effective. By the time the child is 6 months of age, at least three doses of Hib vaccine should have been administered. A fourth dose (booster) should be given between one to one and a half years of age.
TREATMENT
Bacterial meningitis can be treated with antibiotics. It is advisable to start the treatment early as this type of meningitis is rare but can be life threatening.
Advanced bacterial meningitis can result in brain damage, coma, and death.
