Meningitis Research Paper

Meningitis is an inflammation of the meninges, which are the membranes that cover the brain and spinal cord. The disease can be caused by a viral, bacterial, fungal or parasitic infection. Viral meningitis is the most common cause of this disease, yet it’s rarely fatal and can improve without the need of treatment. In the United States, bacterial meningitis continues to be a significant source of morbidity and mortality. Early diagnosis and treatment of meningitis can be the line between life and death for an individual. People may also experience complications if treatment is held off for long periods of time. This can lead to seizures and permanent neurological damages. Further prevention & vaccination can help decrease the spread of meningitis.

INTRODUCTION
Meningitis is an inflammation of the fluid in the spinal cord and the fluid which surrounds the brain. The membranes that cover the brain and the spinal cord are known as the meninges. There are 3 layers that make up the meninges; the dura, arachnoid and the subarachnoid space. The Dura is the tough outer membrane, the arachnoid is a lacy, weblike middle membrane and the subarachnoid space is the delicate, fibrous inner layer that contains many blood vessels that feed the brain and spinal cord. Inflammation is caused by an infection of the fluid surrounding the brain and spinal cord. Some types of meningitis can be contagious and spread rapidly, while others can occur in people with comprised immune systems and certain diseases.
Symptoms of meningitis include fever, headache, confusion, vomiting and stiff neck. These symptoms can develop over several hours, or may take 1 to 2 days. It’s easily mistaken for the flu in the early signs and symptoms of the disease. Children older than the age of 2 may have added symptoms like seizures, sleepiness or difficulty waking up, sensitivity to light, lack of interest in drinking or eating and in some cases a skin rash (meningococcal meningitis). Newborns may not have the classic signs and symptoms of meningitis. Instead they may include high fever, constant crying, excessive sleepiness or irritability, inactivity or sluggishness, poor feeding, a bulge in the soft spot on the top of their head or stiffness in a baby’s body and neck. “Infants with meningitis may be difficult to comfort and may cry harder when being picked up.” (MayoClinic.org)
Depending on the cause of infection, meningitis symptoms can improve on its own, or it can be a serious life-threatening emergency that requires antibiotic treatment. Viral infections are the usual cause of meningitis, but they can also be a bacterial infection. Viral meningitis, also known as aseptic meningitis, is “rarely fatal in people with normal immune systems and depends on the virus involved.”(CDC). It’s caused by viruses like enteroviruses, arboviruses and herpes simplex viruses. Enteroviruses are the most responsible for viral meningitis in the United States. They’re spread from person to person through fecal contamination, eye/nose/mouth secretions, or blister fluid. Viral meningitis may improve without the use of treatment within 7 to 10 days; however, there are vaccines to prevent it.
Bacterial meningitis is the most serious cause of meningitis and can be life-threatening if not treated in time. This infection usually occurs when “bacteria enters the bloodstream and migrate to the brain and spinal cord. It can also occur when bacteria directly invades the meninges, as a result of an ear or sinus infection, or a skull fracture, or rarely, after some surgeries.” The spread of infection is caused by direct close contact with discharges from the respiratory or throat secretion of an infected person. Fortunately, the bacteria that cause meningitis are not contagious. You will not catch the disease by casual contact or by breathing the same air as a person who’s infected with meningitis. (MayoClinic) Many strains can cause bacterial meningitis; however, the most common are Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumonia. It’s important to know the specific bacterial cause in order to be treated properly so it may be prevented from spreading and infecting others.
Haemophilus influenzae (Hib) used to be the leading cause of bacterial meningitis in children in the United Sates. With new vaccines being available in the routine schedule of childhood immunization, the numbers of cases have greatly reduced. Today Neisseria meningitidis, and Streptococcus pneumonia are the leading causes of bacterial meningitis. Streptococcus pneumonia is known to cause pneumonia, ear infections or sinus infections in infants, young children and adults. Neisseria meningitides, also known as meningococcal meningitis, affects mainly teenagers and young adults. It occurs when bacteria from an upper respiratory infection enters the bloodstream. Fortunately, there are vaccines to reduce the occurrence of both this infections.
An uncommonly rare type of meningitis, fungal meningitis, is caused by fungi like Cryptococus and Histoplasma. This type of infection is acquired by inhaling fungal spores from the environment. Certain medical conditions including diabetes, cancer or even HIV can put people at higher risk for fungal meningitis. Parasitic meningitis is another rare case of meningitis which is caused by parasites like Angiostrongylus cantonensis which can contaminate food, water and soil.
Anyone at any age group is susceptible to getting meningitis.

The risk of meningitis is highest among infants due to their immune systems not being fully developed enough to fight back effectively. Adolescents, teens and young adults make up for one third of all cases in the United States. Teenagers tend to share water bottles, make-up or eating utensils which make it easier for bacteria to spread to these individuals and put them at an increased risk for disease. Dormitories also put college students at a high risk due to living in highly populated areas. Increased risks can be caused by sharing items, kissing and engaging in activities where respiratory secretions, throat secretions or saliva is exchanged. Other people who can be put at risk for a certain type of meningitis are individuals traveling to areas where the disease is common, military personal due to them living in close quarters. If you live or work with someone who has the disease, you are also at risk for

meningitis.
The first step in diagnosing meningitis starts by analyzing the spinal fluid from a spinal tap. “The cerebrospinal fluid (CSF) analysis helps determine if the causative agent is bacterial, viral, mycobacterium or otherwise.” (EHA Consulting Group) If a viral infection is detected, a polymerase chain reaction (PCR) amplification can be used. Blood cultures are used to see if there is bacterial growth in the blood. A blood sample may be used for a Gram Stain to be examined under a microscope for bacteria or viruses. Another diagnose is the use of X-rays to view any swelling or inflammation in the head, chest or sinuses. Computerized tomography (CT) scans are used to check for other suspected problems like brain damage.
Since some diagnosis can take several hours to complete, treatment will usually start before the diagnosis is confirmed.

The type of treatment a patient needs will depend on the cause of meningitis. If the cause is unsure, doctors will start both antiviral and antibiotic treatment while determining the cause. For bacterial meningitis, it acquires immediate antibiotic treatment. Recently, cortisone mediations have been given “to ensure recovery and to reduce the risk of brain swelling and seizures.” (Mayo Clinic) Furthermore, a broad-spectrum antibiotic may be recommended until the type of bacteria causing the disease is

determined.
For viral meningitis, antibiotics can’t cure this infection; however, it is recommend getting plenty of fluids, bed rest and using over-the-counter pain medications to help with fever and body aches. The only viral meningitis infection that will need an antiviral medication would be severe cases like herpes virus. Laboratory results will need to be confirmed before fungal meningitis treatment can start due to the antifungal medication possibly causing serious side effects. Cortisone medications may also treat noninfectious meningitis that’s due to allergic reactions or autoimmune diseases. Cancer-related meningitis acquires therapy for the specific cancer.
Patients who are not treated for meningitis happen to come across complications. “In this case it can make matters more severe the longer they go without treatment and can put them or their child at greater risk for seizures and permanent neurological damage.” (Mayo Clinic) These damages can include hearing loss, memory difficulty, learning disabilities, brain damage, gait problems, kidney failure, shock and death. Complications after bacterial meningitis are more common and normally rare in viral meningitis. “The more severe a meningitis infection is, the greater the likelihood of complications.” (NHS) Effects should improve with time during recovery; however, some may need additional therapy.
Further vaccination will help prevent the spread of meningitis. “There are a number of vaccines to help prevent many types of viral and bacterial meningitis.” (NHS) Making sure your child is up-to-date on their vaccinations is a great start. Unfortunately there are no vaccines for meningococcal disease in the United States that’s approved for children under 2 years old. Vaccinations available for meningitis prevention include the MMR vaccine, meningitis C vaccine, the 5-in-1 vaccine and the pneumococcal vaccine. Other helpful ways to prevent this disease can be washing your hands, practicing good hygiene, maintaining a healthy immune system, covering your mouth and, if your pregnant, cooking food properly and avoid unpasteurized milk (soft cheeses, feta, queso, brie and camembert).
EPIDEMIOLOGY
In the United States, bacterial meningitis continues to be a significant source of morbidity and mortality. There are almost 4,100 cases and 500 deaths occurring annually along with an annual incidence of 1.33 cases per 100,000 population. Table 1 shows the changing epidemiology of bacterial meningitis in the US between 1978 through 2007. According to reports made to the CDC, cases among young children under 5 years old have declined from 20,000 to 255 between 1978 and 1998. This decline in incidence rates could be due to the use of the Hib vaccine.

Table 1: Changes of Bacterial Meningitis in the United Sates between 1978 through 2007 (Medscape)
Bacteria 1978-1981 1986 1995 1998-2007
Haemophilus influenzae 48% 45% 7% 6.7%
Listeria monocytogenes 2% 3% 8% 3.4%
Neisseria meningitidis 20% 14% 25% 13.9%
Streptococcus agalactiae (group B streptococcus) 3% 6% 12% 18.1%
Streptococcus pneumoniae 13% 18% 47% 58%

Meningococcal disease incidence rates, caused by N. meningitidis, have gone up and down since World War II. “Approximately 600-1,000 people contract meningococcal disease in the United States each year” and 10-15 % of those who get the disease unfortunately die. (NMA) Meningococcal cases are now at their lowest they’ve been, mostly due to the increased use of meningococcal vaccines. The disease is broken up into five serologic groups that cause the majority of this disease; A, B, C, Y & W-135. Currently serogroup A is uncommon in the United States, while serogroup Y disease has emerged importances