Meningococcal_Disease

Meningococcal Disease Meningococcal disease is a rare but very serious illness that usually appears as meningitis or septicaemia, ‘Meningitis’ means an inflammation of the protective coverings of the brain and spinal cord and ‘Septicaemia’ means blood poisoning, which is a more widespread infection throughout the body. Meningococcal disease appears periodically in every country the world, it has developed into scattered epidemics in Africa and pandemics in Asia. Meningococcal disease is caused by bacteria called ‘meningococci’. Meningococci are common bacteria, and about one in ten people carry them at the back of the throat or nose. Carriers are more often young adults, and less often children and older people. Meningococci are only found in people, and never in animals or the general environment because the Meningococcal bacteria can only infect humans and have never been isolated from animals since the bacteria cannot get iron other than from human sources. Meningococcal disease is uncommon, however it is a very serious disease. The infection can develop very quickly, and can be fatal in about 10% of cases. If the infection is diagnosed early enough and the right antibiotics are given quickly, most people make a complete recovery. About a quarter of people who recover experience after-effects, some of the more common after-effects include headaches, deafness in one or both ears, tinnitus (ringing in the ears), blurring, double vision, aches, stiffness in the joints, and learning difficulties. However most of these problems will get better with time. Meningococcal disease can occur at any age, however babies, children less than 5 years, teenagers and young adults aged 15–24 years of age are most at risk. Persons over the age of two years with a damaged (or no) spleen are at greater risk of meningococcal disease and therefore should be vaccinated against the disease. People who get meningococcal disease are more than three times as likely to be in close contact with smokers. Recent viral illness (especially influenza/flu) is also more common. Avoiding smoky and dusty places might also help to prevent infection. For people who become sick, the average time between being infected and becoming ill is about 3–5 days, but can be up to 7 days. The symptoms of meningococcal disease can resemble symptoms of other diseases, such as influenza/flu. They include fever, headache, stiff neck, irritability, nausea and vomiting, symptoms can develop rapidly and dramatically, within minutes to hours. Fever can become very high and the headache can be intense, there may also be sensitivity to light, and a purple or red rash may appear. Symptoms can progress rapidly, leading to confusion, lethargy, seizures, loss of consciousness or coma, with the symptoms occurring death may follow within days. In infants, signs of meningococcal disease can include excessive crying, excessive sleepiness, difficulty with feeding, and a bulging of the soft spot on the top of the head. The symptoms of meningococcal disease include: In infants and young children: •Fever. •Disinterest in feeding. •Irritability. •Extreme tiredness or floppiness. •Dislike of being handled. •Vomiting and/or diarrhoea. •Turning away from light. •Drowsiness. •Convulsions or twitching. •Rash of red-purple pinprick spots or larger bruises. In older children and adults: •Headache. •Photophobia (dislike of bright lights). •Fever. •Vomiting and/or diarrhoea. •Neck stiffness or aching. •Backache. •Joint pains and sore muscles. •Low appetite •Drowsiness, confusion. •Rash of red-purple pinprick spots or larger bruises The disease is difficult to spread because the germs cannot live for more than a few seconds outside a human body, therefore they cannot be picked up from water supplies, swimming pools, buildings or factories. Only regular close prolonged household and intimate contact spread the bacteria. It also can cause outbreaks in places of crowded living conditions, such as college dormitories or on military bases. The transmission of meningococcal bacteria (meningococci) can happen through low level of salivary contact which includes sharing drink bottles, sharing cigarettes and possibly kissing. Prevention of the spread of the bacterium that causes meningococcal disease, Neisseria meningitides includes frequent hand washing and covering your mouth and nose with a tissue when you sneeze or cough. Neisseria meningitidis is a Gram-negative diplococcal (round bacterium) responsible for causing meningococcal, it is a type of pathogen called pyogenic cocci which are spherical bacteria, with a Cytoplasmic membrane. This micrographic photo depicts the manifestation of gram negative Neisseria meningitidis bacteria (1150X). This organism possesses fimbriae (also called pili) on its cell surface and outer membrane components that help it attach to non-ciliated columnar epithelial cells of later nasopharynx. This bacteria is also capable of living in the cytoplasm of neutrophils A microscopic picture of Neisseria meningitidis recovered from the urethra of an infected male (1125 X). When the cerebrospinal fluid is invaded by this blood borne organism, Originating in the respiratory tract, the meningococcal bacteria travels, via the blood, into the cerebrospinal fluid (the watery liquid that surrounds the brain and spinal cord). During infection, the bacterium releases a toxin into the fluid causing an inflammatory reaction. There are a number of host defence mechanisms to prevent meningitis from occurring. The pharyngeal (part of the throat) and respiratory epithelium acts as a physical barrier, irritation or damage of the mucosa (moist tissue lining) may cause upper respiratory infection, and may lead to invasive disease. Serum bactericidal Immunoglobulin G (antibody) and immunoglobulin M (antibody) are the most important host factors. . The list of treatments mentioned for Meningococcal disease includes the following list: * Emergency hospitalization - many cases require urgent emergency treatment. * Antibiotics * Penicillin * Penicillin G * Ampicillin * Chloramphenicol * Ceftriaxone * Oily chloramphenicol Early diagnosis and treatment is extremely important to prevent serious illness or death. A vaccine called meningococcal polysaccharide is used to prevent infection by using certain groups of the meningococcal bacteria. The vaccine works by causing the body to produce its own antibodies against the disease, the vaccine contains four of the most common types of meningococcal bacteria. Meningococcal polysaccharide vaccine works by exposing you to a small dose of the bacteria or a protein from the bacteria, which causes your body to develop immunity to the disease. Your body produces antigens to fight against the pathogens and immune you against diseases. Mucosal antibodies may provide a second line of defense against meningococcal disease. The reasons behind immunization is to introduce an antigen, derived from a disease causing organism, that stimulates the immune system to develop a protective immunity against that organism, but which does not itself cause the pathogenic effects of that organism. An antigen is defined as any substance that binds to a specific antibody and elicits an adaptive immune response. Once the first infection enters the body in the form of microbes the first attack comes from white blood cells or macrophages. They surround and destroy large groups of microbes during the macrophage attack, the microbes begin to release antigens that tell other cells in the body that it is a foreigner. The microphages then carry the antigens back to other white blood cells known as lymphocytes, T cells and B cells. The purpose is for the T cells and B cells to recognize the antigens should they appear again. If the antigens do reappear, the T cells are designed to release a chemical that destroys the diseased cells carrying the antigens, the B cells also go to work by releasing the antibodies then the antibodies and antigens work together to destroy the microbes. The plasma cells produce even more antibodies to make sure the enemy cells do not have a fighting chance. Once the disease battle is over, some T cells and B cells are designed to remember the identity of the diseased cells. So if the disease should appear again, the immunity attack will be quicker. The Meningococcal Vaccination through protein antigens will usually result in both a cellular (T-cell) and humoral (B-cell) immune response. For protection against extracellular bacterial infections, like Neisseria meningitidis, bactericidal and opsonic antibodies are of crucial importance, while T cells play a more indirect role by regulating the antibody response in terms of immunoglobulin class switch and magnitude of response. T cells are also necessary for the induction of immunological memory and can indirectly induce killing of bacteria by activating phagocytes. References http://www.healthinsite.gov.au/topics/Meningitis_and_Meningococcal_Infections http://www.meningococcal.org/the_disease.html http://brainfoundation.org.au/a-z-of-disorders/40-meningococcal-disease http://www.cdc.gov/mmwr/preview/mmwrhtml/rr4907a1.htm www.meningococcal.org/prevent.html www.ncirs.edu.au/.../fact.../meningococcal-vaccines-fact-sheet.pdf www.ncbi.nlm.nih.gov/pubmed/19202131 www.springerprotocols.com/Abstract/doi/10.1385/1-59259-148-5:339 www.jimmunol.org/content/171/8/4263.full.pdf www.deepdyve.com www.caringforkids.cps.ca