Meningococcal Disease

Meningococcal disease is a severe bacterial infection caused by Neisseria meningitidis (meningococcus). It has a high mortality rate if untreated but is preventable with vaccines. This disease is notorious for causing meningitis and sepsis, both of which can lead to severe illness, death, and disability.

Signs and Symptoms

Meningitis

Patients with meningococcal meningitis often present with high fever, stiff neck (nuchal rigidity), severe headache, vomiting, and purpura. Other symptoms may include photophobia, altered mental status, or seizures. Petechiae, small red or brown spots on the skin, are common but their absence does not rule out the disease. Immediate intravenous antibiotic treatment is very important to improve prognosis.

Meningococcaemia

Meningococcaemia initially presents with flu-like symptoms such as fever, nausea, myalgia, headache, and chills. As the disease progresses, it can cause septic shock, purpura, hypotension, cyanosis, petechiae, and multiple organ dysfunction syndrome. The characteristic petechial rash appears star-like due to blood vessel damage. Meningococcal sepsis has a higher mortality rate than meningitis but lower risk of neurological sequelae.

Diagnosis

Diagnosis is primarily clinical, supported by laboratory tests. A lumbar puncture can confirm meningitis by revealing bacteria in cerebrospinal fluid. Blood cultures and skin biopsies of petechiae can also identify N. meningitidis. Time is very important, and treatment should not be delayed while waiting for diagnostic confirmation.

Treatment

Immediate treatment is essential and usually begins with intramuscular benzylpenicillin in primary care, followed by urgent hospital transfer. In hospitals, intravenous broad-spectrum antibiotics like cefotaxime or ceftriaxone are preferred. Supportive measures include IV fluids, oxygen, and inotropic support. Steroid therapy may help some adult patients.

Complications

Early complications include raised intracranial pressure, disseminated intravascular coagulation, seizures, and organ failure. Later complications often involve deafness, blindness, lasting neurological deficits, reduced IQ, and gangrene leading to amputations.

Prevention

Vaccination is the most effective prevention method. There are vaccines for six serogroups (A, B, C, X, Y, and W135), which are responsible for most human cases. Vaccines offer protection ranging from three to over eight years, depending on the type.

Vaccinations

Children

Children aged 2–10 at high risk should receive primary immunisation. Safety and efficacy in children under 2 are not well-established.

Adolescents

Primary immunisation is recommended for all adolescents aged 11–12 and unvaccinated older adolescents at 15. Conjugate vaccines are preferred, but polysaccharide vaccines are alternatives if necessary.

Adults

Immunisation is advised for college students living in dormitories, adults in endemic areas, and military recruits. Conjugate vaccines are preferred for those under 55.

Medical Staff

Healthcare workers exposed to N. meningitidis should receive routine immunisation. Unvaccinated staff in contact with infected patients should receive prophylactic antibiotics.

Travellers

Immunisation is recommended for travellers to endemic regions. Saudi Arabia requires Hajj and Umrah pilgrims to be vaccinated.

HIV-Infected Individuals

HIV-infected individuals may receive primary immunisation. Vaccines do not affect CD4+ T-cell counts or viral load.

Antibiotics

Prophylactic antibiotics like rifampin, ceftriaxone, ciprofloxacin, and penicillin are effective in eradicating N. meningitidis in carriers. Side effects are minimal.

Epidemiology

Africa

Meningococcal disease is significant in Africa, particularly in the meningitis belt. Epidemics are common during the dry season. Overcrowded living conditions and respiratory infections increase transmission risk.

Florida

As of June 2022, an outbreak in Florida has resulted in 26 cases and seven deaths.

History and Etymology

The term "meningococcal" derives from the Greek meninx (membrane) and kokkos (berry). The disease was first described in 1805 by Gaspard Vieusseux. The bacterium N. meningitidis was identified in 1887 by Anton Wiechselbaum, linking it to epidemic meningitis.

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Self-assessment MCQs (single best answer)

What bacterium causes meningococcal disease?

Which symptom is NOT typically associated with meningococcal meningitis?

What is the characteristic appearance of the rash in meningococcaemia?

What is the first line of treatment in primary care for suspected meningococcal disease?

Which of the following is NOT a recommended vaccination group for meningococcal disease?

What is the primary method of diagnosis for meningococcal meningitis?

Which of the following is a common complication of meningococcal disease?

Which antibiotic is commonly used for prophylaxis against meningococcal disease?

What season is meningococcal disease most likely to cause epidemics in Africa?

Which of the following is NOT a symptom of meningococcaemia?