Meningitis: causes, symptoms, and treatment

Meningitis

The area surrounding the brain and the spinal chord is surrounded by a network of three-layered membranes called the meninges. The fluid associated with these membranes surround the central nervous system, consisting of the brain and the spinal chord. The inflammation of the meninges resulting from the infection of the surrounding fluid results in meningitis. This inflammation can be caused by both bacterial and viral infection. Viral meningitis is less serious and, unless the person suffering has a weakened immune system, the body manages to fight off the infection. On the other hand, bacterial infections can be more severe and require aggressive treatment by antibiotics. Three primary causes of bacterial infections are known. The most common is Haemophilus influenzae type b (Hib), for which a vaccine has been developed and poses less of a hazard. More recently, two other bacteria, Streptococcus pneumoniae and Neisseria meningitides, have been identified as known to cause meningitis. (CDC 2009)

Natural History of the Disease

The first incidences of meningitis were discovered in Switzerland in 1805.(SanofiPasteur 2009) it wasn't until more than 80 years later that the bacterium (Neisseria meningitides) that caused it was isolated -- giving the disease a name. Before penicillin, the broad spectrum antibiotic was used, about 80% of the people infected died from meningitis. With the development of vaccines and specific antibiotics, incidences of death have been significantly reduced to a rarity.

It takes between two to seven days for the onset of symptoms after the infection first occurs. Though, the symptoms might appear as early as three or four days.

Symptoms

The symptoms of the disease include fevers that spike very quickly. This is accompanied by a stiffness of the neck and debilitating headaches. Vomiting and nausea frequently occur. A skin rash also arises. In infants and children, who cannot communicate the symptoms effectively, in addition to a fever and rash, there are unmistakable signs of irritability. Seizures are often observed. The person affected might become mentally unstable and irritable. It is often difficult to wake a person up from the sleep. Also, very rarely, permanent disability does occur among some individuals. In the most severe cases coma and death can occur (though these are relatively rare).

Diagnosis

Because the treatment modalities for the disease differ depending upon the infecting agent, it is important to be able to first distinguish, whether the infection is bacterial or viral. A spinal tap to draw out spinal fluid is followed by the development of a bacterial culture to identify the bacterium. As has been mentioned earlier in this essay, because of vaccinations against Hib, the H. influenzae is rarely the cause of bacterial meningitis.

Modes of Transmissions and Risk Factors

Both the viral and bacterial forms of the disease are contagious. They are however, not virulently contagious like influenza or rhinitis. There are a lot of carriers of the disease; approximately 15% of normal healthy adults carry the bacteria in the nasal membranes. Carriers might pass on the disease, but they may not suffer from it for days, months, years or even indefinitely. The cause of susceptibility, other than the obvious -- a weakened immune -- system is not known.

People who come in close contact, such as members of a family, children and youngsters at school of day care, those that are sexually or otherwise intimate will transmit the disease. These individuals are at high risk. If one of a cohort come down with symptoms, and it is proven to be meningitis, then others in close contact have to be vaccinated or otherwise medicated. The Center for Disease Control also through their own research identifies at-risk populations for vaccinations.(Humble 2009) the at large populace is not vaccinated. Members of the military as well as workers in medical facilities are at a higher risk and have to be necessarily medicated. Military personnel were one of the first to receive compulsory doses of antibiotics to prevent incidents of meningitis.

Treatment

There are several vaccines that are sage and have been successfully used for the treatment of meningitis. The two vaccines are: U.S. Meningococcal polysaccharide vaccine (MPSV4 or Menomune®) and Meningococcal conjugate vaccine (MCV4 or MenactraT). The first has been in use for almost three-decade, the second has been licensed for use in 2005. The first is used for individuals who might be at higher risk such as children or the elderly. The second is used for those between 11 and 55 years of age.

Prevalence and Incidence patterns

With early detection and treatment, coma and death are nearly impossible. Incidents of infection also have been significantly reduced with the use of vaccines. This is especially true in developed countries with a better medical infrastructure. On the other hand, in developing countries especially in Africa, the lack of knowledge and availability of vaccines and treatment facilities, and with people living in close proximity, infections and spread can cause mini-epidemics, resulting in death among the vulnerable. People who travel often or travel to developing countries are advised to get vaccinated before they leave the United States.