Emerging Cases of Meningococcal Disease: Symptoms and Vaccination Options

Recent reports confirm the detection of new meningococcal disease cases, including two women hospitalized in Tasmania, bringing the year's total to 48 cases nationwide. Health officials emphasize the importance of recognizing symptoms and considering vaccination to prevent this serious illness.

Invasive meningococcal disease is a potentially fatal condition caused by the bacterium Neisseria meningitidis. It spreads rapidly through the bloodstream to vital organs. Early medical intervention is crucial, as delayed treatment can lead to severe complications and long-term disabilities such as cognitive, physical, or psychological impairments.

The bacteria are carried harmlessly in the nose or throat of about 10% of the population, but they do not transmit easily through common activities like sharing drinks or simply breathing shared air. Transmission occurs mainly through close, extended contact involving saliva or respiratory secretions—such as intimate kissing or living in close quarters. Carriers are typically asymptomatic.

Anyone can be affected, but certain groups are at higher risk. These include infants under one year of age, adolescents, young adults aged 15–25, and individuals lacking a functioning spleen or those who are immunocompromised. Symptoms often appear suddenly and include high fever, sensitivity to light, and a prominent non-blanching rash. Younger children may show irritability, difficulty waking, or refusal to feed.

The disease commonly manifests as meningitis, inflammation of the brain lining, or septicemia, a severe bloodstream infection. It can also cause infections in the bones, lungs, or eyes.

There are multiple strains of meningococcal bacteria, but types A, B, C, W, and Y are most associated with serious illness. The bacteria evade immune defenses through a sugar capsule on their surface, which varies among strains. Vaccines are available to target the most common and dangerous strains.

Two main vaccines are on the market: one protecting against strains A, C, W, and Y (MenACWY), and another targeting meningococcal B (MenB). These vaccines differ in composition but are safe for individuals six months of age and older, including those with weakened immune systems.

The MenACWY vaccine is included in Australia's national immunization program, offering free protection to infants at 12 months and a catch-up program for teenagers. It not only prevents disease but also reduces bacteria colonization, lowering transmission risk. The MenB vaccine is recommended for infants from six weeks but is only subsidized in certain regions; otherwise, parents typically pay A$220–270 for two doses. Although highly effective, the MenB vaccine does not eliminate bacteria from the throat nor reduce its spread.

Additional groups eligible for vaccination include people with asplenia, immunocompromised conditions, travelers to high-risk areas, and laboratory workers. Public health measures and vaccination programs have significantly decreased invasive meningococcal disease rates in Australia since their implementation.

Interestingly, the MenB vaccine may also reduce rates of gonorrhea by 33–47%, due to similarities between Neisseria meningitidis and gonococcal bacteria. Ongoing research aims to better understand bacterial behavior, immune evasion, and cross-protection between these pathogens.

Source: https://medicalxpress.com/news/2025-06-cases-meningococcal-disease-symptoms-vaccinated.html