Menigitis And Increased Risk In Teens And Children Biology Essay

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Every year about 1,500 Americans are stroked with serious and potentially fatal bacterial infection that causes disease called Meningitis. For some reason adolescents and young adults are at increased risk of contracting this infection. Therefore National Meningitis Association (NMA) which is a national non-profit charity founded in 2002 is hard at work to educate and increase awareness of meningitis disease. Among the members are those who were personally affected by the disease and their primary mission is to educate families, medical professionals, and others about meningitis and its prevention. Particularly NMA's center of attention is adolescents and young people. Sadly meningitis not only appears in the U.S. but targets mostly the poorest counties on the African continent. To be able to fight this disease we need to understand it first.

The first symptoms of meningitis were first documented in the middle Ages during the time of the Bubonic Plague but meningitis was actually identified in 1805 in Geneva, Switzerland during the outbreak of the disease that was yet to be named. Seventy years later, in 1887 the first causative agent Neisseria Meningitidis was identified and isolated (1). During both World War I and World War II the meningitis was common due mostly to poor living conditions of soldiers. According to Science Week in the first decade of the 20th century, 75 to 85 percent of people who contracted meningitis died from the disease (2). In 1944 the infection was successfully treated with intravenous penicillin and considered to be most effective treatment. Outbreaks of meningitis were also documented in other parts of the world such as Africa and Europe. In 1909 on the West Coast of Africa the infection was documented as huge burden in the form of a cyclical epidemic. The region of Africa that was hit hardest by the disease extended from Senegal and Gambia in the East to Ethiopia in the West. This is very populated region of over 300 million people and it suffers massive epidemics every 8-12 years.

The general question that people ask is what meningitis is and what causes it. Center of Disease Control and Prevention puts it simply, meningitis is an inflammation of the membranes that cover the brain and spinal cord (3). The word "meningitis" comes from the Modern Latin word meninga and the Greek word Menix meaning "membrane". The suffix "itis" comes from Greek word itis meaning "pertaining to" (4). There are two main forms of meningitis, bacterial meningitis and viral meningitis. Bacterial meningitis affects fewer people that the viral form, but very often results in more serious health consequences if it is not treated right away. Bacterial meningitis is fatal in 1 in 10 cases and leaves 1 in 7 survivors with severe disability that is caused by brain injury. Viral meningitis is far less common than the bacterial form and in most cases less devastating. Interestingly humans are the only natural host of meningococcus (8).

Bacterial meningitis furthermore is divided into several types: meningococcal, pneumococcal, neonatal, staphylococcal, and heamophilus influenza type B (Hib). Meningococcal meningitis is caused by the bacteria Neisseria meningitidis also known as meningoccocus. N. meningitidis is a gram-negative diplococcus that colonizes the upper respiratory tract of 10 percent or more of humans and is transmitted from person to person by aerosol droplets or contact with respiratory tract secretions for example by kissing, sharing drinking glasses, and mouth-to-mouth resuscitation (11). Most common cases occur in children during the season of winter and spring. This may cause local epidemics in schools, college dormitories, and military bases (5). Pneumococcal meningitis is caused by bacteria Streptococcus pneumoniae also known as pneumococcus. These bacteria also cause several respiratory diseases such as pneumonia, ear and sinus infections. It has a fatality of about 25 percent, and also the consequence is higher occurrence of brain damage than other forms of the disease. The bacteria that cause meningococcal and pneumococcal meningitis live in the back of the nose and throat or in the upper respiratory tract. It is spread among people by sneezing, coughing, as well as kissing. Since these bacteria cannot live outside the body for long time it is not likely that it can be picked up from swimming pools. People can carry these bacteria for long time, day, weeks, or months without becoming sick. About 25 percent of the population carries these bacteria but not often the bacteria overcome body's defense system and attack the cerebral spinal fluid causing meningitis (6). Neonatal meningitis affects newborn babies and is caused by bacterium called group B beta-hemolytic streptococcus, or group B strep, for short (6), Escherichia coli, and Listeria monocytogenes. Staphylococcal meningitis is very rare but can be fatal. It usually develops as a complication of surgical procedure. The last type of meningitis is Haemophilus influenza type B(Hib) and is caused by haemophilus bacteria. In the past it was one of the deadliest diseases of childhood until in 1985 Hib vaccine was introduced into routine immunization program for children in United States. This almost eliminated Hib meningitis in US.

Viral meningitis also called aseptic meningitis is found worldwide. It is far more common than bacterial type, and in most cases it is less devastating. In most cases the symptoms are mild or not detected and person fully recovers without complications in about a week. Very often it is undiagnosed because the symptoms resemble that of a common flu. Viral meningitis is caused by number of viruses in which many are linked to other diseases. About half of the cases in the United Stated are caused by the common intestinal viruses or enterovirusus (7). This viruses live in the gut and are usually shed in feces and discharges from mouth and nose. Cases of viral meningitis that occur in summer and fall are usually caused by mosquito borne viruses. The other cases that occur in the winter are likely caused by other diseases. It is important to know the symptoms of meningitis because of the seriousness of the disease and its rapid progress. Knowing whether meningitis is caused by viral or bacterial infection is important because of the seriousness of the illness and the treatment options. It is not always easy to recognize Meningitis because in many cases it may be progressing without any symptoms. Common symptom of meningitis for anyone over the age 2 is high fever, headache, and stiff neck. The last one is more classic symptom and that is the why during examinations pediatricians ask a child to look at the ceiling and at the toes if they suspect that a child may have meningitis. In addition to a stiff neck, high fever and headache there are other symptoms that are looked for. This includes vomiting, photophobia (sensitivity to light), irritability and seizures, rash, mental status changes such as lethargy, delirium, and hallucinations (4). In infants whose soft spot on the head has not closed yet, there may be a bulging fontanel. Babies will also have high pitched moaning cry, will be not easy to wake up, will refuse to eat, and will have rapid breathing. These symptoms can develop very quickly, over several hours or from one to two days. Oder children may experience severe pains in back and bones, sleepiness and confusion, cold hands and feet, shivering, and red or purple spots that do not fade under pressure.

People who are suspected of having meningitis should receive immediate treatment because the disease is potentially serious and progresses very quickly causing irreversible neurological impairment. Early treatment involves strong doses of intravenous antibiotics, such as prednisone which is a corticosteroid and is it given to relive brain pressure and reduce swelling. It can also prevent hearing loss with is common in patients. In cases of viral meningitis the virus cannot be killed by antibiotics, therefore the treatment does not involve medications. If the viral infection is mild the patient may be allowed to stay home, while the more serious infection is treated in the hospital using supportive care. Anticonvulsants such as Dilantin are used to prevent seizures, and corticosteroids to reduce brain inflammation. Pain medicine and sedatives are used to make patient more comfortable. The prognosis depends on the case of meningitis, seriousness of illness, and how fast treatment was received. In most cases patients who have minor case of viral meningitis recover fully, while patients with bacterial meningitis are more likely to suffer complications caused by the disease. In more serious cases meningitis may cause hearing or speech loss, blindness, permanent brain damage, cognitive disabilities, lock of muscle control, memory loss, and seizures. These patients with lasting complications will need medications, long term therapy, and supportive care.

To understand better viral and bacterial meningitis doctors and scientists are hard at work conducting meningitis research. The research studies are designed to answer some important questions and to find out if new approaches are safe and effective. Meningitis research has already led to many advances, but scientists still search for better and more effective methods for preventing or treating the disease. Current research efforts include better understanding of the disease and the molecular mechanisms involved in the protection and disruption of the blood-brain barrier. Researchers hope that this could lead to the development of new treatments. Other scientists hope to define at the molecular level how some viruses overcome the body's defense mechanism and interact with target host cells. Current research includes investigating new chemotherapy-based treatment for neoplastic meningitis which is caused by cancer and to better understand how central nervous system responds to inflammation, the role of T cells in suppressing infection in the brain. Scientists also are looking at possible neuroprotective medicines. This research involves therapeutic approach, testing medicines that block the damage that results from meningitis. During the last few years scientists puzzle over the question why crippling epidemics of meningitis sweeps across Africa during the dry season, and what triggers the epidemics. The last epidemic in 1996-97 reported hundreds of thousands sick and killed more than 25,000 in ten African countries (9). In the year 2007 next epidemic brought alarming death number as well. The doctors and scientists work with the African officials to prevent these occurrences by implementing vaccinations before the dry season's starts. The subject in this case is the Burkina Faso, which is the poorest population in the world. The vaccine that is used in this country is a 1960s design using polysaccharides which is still affordable but does not work too well. It prevents those that carry the bacterium from getting ill but does not stop them from spreading it to others (9). In addition the immunity only lasts for a few years and for children under the age of two it has minimal effect. Because the vaccine is not very efficient WHO suggested that it should be used only to control the epidemics but not prevent them. F. Marc LaForce is one of the people that work on the Meningitis Vaccine Project (MVP) to develop an affordable, effective, and long lasting vaccine for African meningitis. LaForce is an infectious disease expert and former meningitis officer for the U.S. Centers for Disease Control and Prevention (CCD). He worked with many officials to reduce the cost of the vaccine for African countries to 50 cents per dose, which was affordable price for many of the African governments (9). The road to provide the conjugate vaccines at this price was very challenging and met with difficulties but in the end the clinical trials were conducted at the several poorest African sites. In Gambia in 2007 the trial of 600 healthy toddlers from age of 12 to 23 months, showed that the conjugate vaccine produced antibody titers about 20-fold higher than polysaccharide vaccine (9). LaForce and his partners believe that the vaccine may be able to protect person for ten years. Still in other phases of the clinical trials the testing was done on the safety and immunogenicity of a single dose the age group of 2-29 years olds, as well as study of immunogenicity of different doses schedules in infants. If the outcome of the clinical trial are successful and the WHO prequalifies the vaccine, and if the founding come through the vaccine would be introduced by MVP in Burkina Faso, Mali, and Niger in 2009/10. The vaccine will be given first to the populations that are at the highest risk, and by 2016 there should be enough vaccine for the population in the meningitis belt which is roughly about 250 million people (9).

Many scientists, doctors, and researchers try to understand better meningitis disease and find out what contribute to certain times that outbreaks occur. There are times during the year when this disease appear more often that the other times, for example in Africa during the dry season and in U. S. during fall/winter. Laura M. Kinlin, C. Victor Spain, Victoria Ng, Caroline C. Johnson, Alexander N. J. White and David N. FismanIt are authors who wanted to evaluate the environmental factors on the invasive meningitis disease (IMD) in one of the U.S. city, Philadelphia in state of Pennsylvania. By studying monthly weather pattern and the IMD occurrence, they hoped to find seasonal factors that might otherwise confound the relation between environment and IMD (10). Because N. meningitidis remains a leading cause of septicemia and bacterial meningitis in North American children, the high case-fatality rates associated with invasive infection, and the risk of transmission to close contacts it adds up to be continuous public health importance. In this study authors focused on the area of Philadelphia, its climate, and environmental exposures. They obtained meteorological data for the period 1995-2006 from the weather station at Philadelphia International Airport and ultraviolet index forecast estimates for Philadelphia during the same period from the National Weather Service's Climate Prediction Center (10). Air quality was also taken into study, such as concentration of lead, ozone, particulate matter, and sulfur oxides. Information on cases of IMD occurring between January 1, 1995, and December 31, 2006, was obtained from the Philadelphia Department of Public Health, which included report date, patient's sex, age, outcome, and N. meningitis serogroup (10). The date on which the symptoms began was considered the date of disease onset for the study. Other environmental exposures identified in this study that were linked to the N. meningitis cases were humidity and temperature. As the results were being evaluated, there were 153 cases confirmed and 9 probable. Case count increased during winter, spring and fall. No significant relation was found between environmental risks, such as humidity and temperature although more cases were reported during winter when humidity is low. This is also true for the African continent, but not for countries as Israel, New Zealand, and England. Projections of warmer, wetter winters might suggest an increased risk of meningococcal disease based on the association between relative humidity and disease risk (10). As a summary of this study the authors decided that the seasonal nature of meningitis in Philadelphia was confirmed and environmental factors that might contribute to the observed seasonality were evaluated. Also during months that humidity was law, there is possibility that the disease has higher rate due to dryness in the upper respiratory tract and higher susceptibility of bacterial invasion. Also staying indoor in crowded places adds up to the higher risk of infections.

Because meningitis disease can be rapidly fatal and can results in severe neurological disabilities despite antibiotic therapy it is important that population is made aware and educated about this disease. Adolescents and young adults 15 to 24 years of age have a higher incidence of disease and a higher fatality rate than other populations, therefore vaccination is a key for prevention of meningitis (11). N. meningitidis is the most common cause of bacterial meningitis in children and young adults in the United States and the second most common cause of community-acquired meningitis in adults. HiB vaccine in children will help prevent one type of meningitis and pneumococcal conjugate vaccine is now a routine childhood immunization and is very effective at preventing pneumococcal meningitis. Our researchers and scientist are working hard in hopes how to better protect population from this disease, to find new treatments and improve vaccination. Educating schools, health professionals, and general population is very crucial in early detections and treatment. Education and knowledge is the first step in identification, prevention, and treatment of meningitis.