3 What are the meninges?The meninges are membranes that cover and protect the brain and spinal cord. The meninges consist of three layers of protective tissueDura mater- most superior of meningeal layersArachnoid- middle layer of the meningesPia mater- inner most layer of the meningesFunctionProtects Cranial Nerves and Spinal CordIts name means "hard mother" in Latin and it is tough and inflexible. This tissue forms several structures that separate the cranial cavity into compartments and protect the brain from displacement.
4 What is meningitis?Meningitis is a disease caused by the inflammation of the protective membranes covering the brain and spinal cord known as the meningesThe inflammation is usually caused by an infection of the fluid surrounding the brain and spinal cord.
5 How does meningitis develop? Meningitis may develop in response to a number of causes, usually viruses or bacteriameningitis can also be caused by physical injury, cancer or certain drugsThe five main types of meningitis are:Bacterial meningitis, Viral meningitis, Parasitic meningitis, Fungal meningitis, Non-infectious meningitisThe severity of illness and the treatment for meningitis differ depending on the causeThus, it is important to know the specific cause of meningitis.
6 Viral Meningitis Is the most common type of meningitis Often less severe than bacterial meningitisMost people (usually) get better on their ownInfants younger than 1 month and those with suppressed immune systems more severe illness
7 Viral meningitis Causes Non-polio enteroviruses are most common cause of viral meningitis in the U.S.Common in summer to fallOnly small number of peo0ple with an enterovirus develops meningitisOther Viruses that can cause meningitis are:Mumps, Measles, Influenza, West Nile VirusCommon in summer to fall when these viruses spread most often
8 Viral Meningitis Risk Factors Any age group, some are at higher risk including:Children younger than 5 yrs. of agePeople with suppressed immune systems caused by other disease, medications, and recent organ or bone marrow transplantationsTransmissionClose contact with person who has viral meningitis may infect you with the virus that made person sick, but low chances of you developing meningitis
9 Viral meningitis Symptoms In Infants: Fever, Irritability, poor eating In Adults: Fever, Headache, Stiff neck, Sensitivity to bright lightDiagnosisNaso-oropharyngeal swabs, stool, cerebrospinal fluid, blood, and serumTreatmentMost cases have no specific treatmentPreventionWash hands, avoid touching your face with unwashed hands, stay home when sick, Vaccinate against viral infections that can lead to viral meningitis
10 Bacterial meningitis Usually severe Most people can recover, but it can cause serious complicationsBrain damage, hearing loss, learning disabilitiesSeveral pathogens can cause bacterial meningitisLeading causes in the U.S. include:Haemophilus influenzae (most often caused by type b, Hib), Streptococcus pneumoniae, group B Streptococcus, Listeria monocytogenes, and Neisseria meningitidis.
11 Risk factorsAge- children and teens are at a higher risk for bacterial meningitisCommunity setting- Infectious diseases tend to spread more quickly where larger groups of people gather together. College students living in dormitories and military personnel are at increased risk for meningococcal meningitis.Season- The infection occurs more often in winter or spring
12 transmissionThe germs that cause bacterial meningitis can be contagiousSome bacteria can spread through the exchange of respiratory and throat secretions fore exampleKissing, sneezing or coughing on someone, living in closed quarters with an infected personFortunately, most of the bacteria that cause meningitis are not as contagious as diseases like the common cold or the fluHealthy people can carry the bacteria in their nose or throat without getting sick. Rarely, these bacteria can invade the body and cause disease. Most people who ‘carry’ the bacteria never become sick.
13 Symptoms Can show up in a person by: Sudden onset of a fever, headache and stiff neckIt will often have other symptoms, such asNauseaVomitingIncreased sensitivity to light (photophobia)Altered mental status (confusion)The symptoms of bacterial meningitis can appear quickly or over several days. Typically they develop within 3-7 days after exposure.
14 Tests to diagnose meningitis If the health care provider thinks meningitis is possible, a lumbar puncture (“spinal tap") should be done to remove a sample of spinal fluid (cerebrospinal fluid, or CSF) for testing.Tests that may be done include:Blood cultureChest x-rayCT scan of the headWhite blood cell (WBC) count
15 Treatment Antibiotics should be started as soon as possible Appropriate antibiotic treatment of the most common types of bacterial meningitis should reduce the risk of dying from meningitis to below 15%, although the risk remains higher among young infants and the elderlyCeftriaxone is one of the most commonly used antibiotics for meningococcal meningitisPenicillin in high doses is almost always effective, too.If the patient is allergic to penicillin, chloramphenicol may be usedSometimes corticosteroids may be used, especially in children
16 PreventionPeople in close contact with someone who has meningococcal meningitis should be given antibiotics to prevent infectionSuch people include: household members, roommates in dormitoriesVaccines are effective for controlling epidemics. They are currently recommended for:AdolescentsCollege students in their first year living in dormitoriesMilitary recruitsTravelers to certain parts of the world
17 Recent Meningococcal disease outbreaks Two U.S. universities are experiencing unrelated outbreaks of serogroup B meningococcal diseasePrincenton University8 reported cases1st case reported in March 2013Serogroup B meningococcal vaccine is being usedUniversity of California, Santa Barbara4 confirmed cases reported during November 2013