industrialized countries, have been increasingly used; pcr can rapidly identify the organism, and works even after antibiotics have been given. prevention all recent contacts of the infected patient over the seven days before onset should receive medication to prevent them from contracting the infection. this especially includes young children and their child caregivers or nursery-school contacts, as well as anyone who had direct exposure to the patient through kissing, sharing utensils, or medical interventions such as mouth-to-mouth resuscitation. anyone who frequently ate, slept or stayed at the patient's home during the seven days before the onset of symptom, or those who sat beside the patient on an airplane flight or classroom for eight hours or longer, should also receive chemoprophylaxis. the agent of choice is usually oral rifampicin for a few days. receiving a dose of the meningococcal vaccine before traveling to a country in the "meningitis belt" or having a booster meningitis vaccine, normally five years apart could prevent someone from getting an infection from the pathogen. vaccination main article: meningococcal vaccine united states a number of vaccines are available in the u.s. to prevent meningococcal disease. some of the vaccines cover serogroup b, while others cover a, c, w, and y. the centers for disease control and prevention (cdc) recommends all teenagers receive menacwy vaccine and booster, with optional menb. menacwy and menb are also recommended for people of other ages with various medical conditions and social risk factors. a meningococcal polysaccharide vaccine (mpsv4) has been available since the 1970s and is the only meningococcal vaccine licensed for people older than 55. mpsv4 may be used in people 2–55 years old if the mcv4 vaccines are not available or contraindicated. two meningococcal conjugate vaccines (mcv4) are licensed for use in the u.s. the first conjugate vaccine was licensed in 2005, the second in 2010. conjugate vaccines are the preferred vaccine for people 2 through 55 years of age. it is indicated in those with impaired immunity, such as nephrotic syndrome or splenectomy. in june 2012, the u.s. food and drug administration (fda) approved a combination vaccine against two types of meningococcal diseases and hib disease for infants and children 6 weeks to 18 months old. the vaccine, menhibrix, was designed to prevent disease caused by neisseria meningitidis serogroups c and y, and haemophilus influenzae type b (hib). it was the first meningococcal vaccine that could be given to infants as young as six weeks old. in october 2014 the fda approved the first vaccine effective against serogroup b, named trumenba, for use in 10- to 25-year-old individuals. africa in 2010, the meningitis vaccine project introduced a vaccine called menafrivac in the african meningitis belt. it was made by generic drug maker serum institute of india and cost 50 u.s. cents per injection. beginning in burkina faso in 2010, it has been given to 215 million people across benin, cameroon, chad, ivory coast, ethiopia, ghana, mali, niger, mauritania, nigeria, senegal, sudan, togo and gambia. the vaccination campaign has resulted in near-elimination of serogroup a meningitis from the participating countries. treatment persons with confirmed n. meningitidis infection should be hospitalized immediately for treatment with antibiotics. because meningococcal disease can disseminate very rapidly, a single dose of intramuscular antibiotic is often given at the earliest possible opportunity, even before hospitalization, if disease symptoms look suspicious enough. third-generation cephalosporin antibiotics (i.e. cefotaxime, ceftriaxone) should be used to treat a suspected or culture-proven meningococcal infection before antibiotic susceptibility results are available. clinical practice guidelines endorse empirical treatment in the event a lumbar puncture to collect cerebrospinal fluid (csf) for laboratory testing cannot first be performed. antibiotic treatment may affect the results of microbiology tests, but a diagnosis may be made on the basis of blood-cultures and clinical examination. epidemiology n. meningitidis is a major cause of illness, developmental impairment and death during childhood in industrialized countries and has been responsible for epidemics in africa and in asia. every year, about 2,500 to 3,500 people become infected with n. meningitidis in the us, with a frequency of about 1 in 100,000. children younger than five years are at greatest risk, followed by teenagers of high school age. rates in the african meningitis belt were as high as 1 in 1,000 to 1 in 100 before introduction of a vaccine in 2010. the incidence of meningococcal disease is highest among infants (children younger than one year old) whose immune system is relatively immature. in industrialized countries there is a second peak of incidence in young adults, who are congregating closely, living in dormitories or smoking. vaccine development is ongoing. it is spread through saliva and other respiratory secretions during coughing, sneezing, kissing, and chewing on toys. inhalation of respiratory droplets from a carrier which may be someone who is themselves in the early stages of disease can transmit the bacteria. close contact with a carrier is the predominant risk factor. other risk factors include a weakened general or local immune response, such as a recent upper respiratory infection, smoking, and complement deficiency. the incubation period is short, from 2 to 10 days. in susceptible individuals, n. meningitidis may invade the bloodstream and cause a systemic infection, sepsis, disseminated intravascular coagulation, breakdown of circulation, and septic shock. history in 1884 ettore marchiafava and angelo celli first observed the bacterium inside cells in the cerebral spinal fluid (csf). in 1887 anton weichselbaum isolated the bacterium from the csf of patients with bacterial meningitis. he named the bacterium diplococcus intracellularis meningitidis. biotechnology components from neisseria meningitidis are being harnessed in biotechnology. its cas9 enzyme is a useful tool in crispr gene editing because the enzyme is small and has distinct targeting features to the commonly used enzyme from streptococcus pyogenes. the cell-surface protein frpc from neisseria meningitidis has been engineered to allow covalent coupling between proteins, because it generates a reactive anhydride when exposed to calcium. the bacterium also expresses unique enzymes able to cleave iga antibodies.