African meningitis belt

Meningococcal Meningitis Range

African Meningitis Belt

The African Meningitis Belt is a region in sub-Saharan Africa where the incidence of meningitis is significantly higher than in other parts of the world. This area stretches from Senegal in the west to Ethiopia in the east, covering more than 25 countries. The belt is characterized by its dry and dusty climate, which has been associated with the seasonal outbreaks of meningitis that occur during the dry season, typically between December and June.

Epidemiology

Meningitis is an inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The disease can be caused by various pathogens, including viruses, bacteria, and fungi, but the most severe outbreaks in the African Meningitis Belt are caused by the bacterium Neisseria meningitidis. This bacterium has several serogroups, but serogroups A, C, W, and X are most commonly associated with epidemics in this region.

The African Meningitis Belt has the highest rates of meningococcal meningitis in the world, with epidemics occurring at intervals of 5 to 12 years. These epidemics can be devastating, with case fatality rates as high as 10%, and high morbidity among survivors, including neurological damage and hearing loss.

Prevention and Control

Efforts to control meningitis in the African Meningitis Belt have focused on vaccination. The introduction of the MenAfriVac vaccine in 2010, which targets Neisseria meningitidis serogroup A, has significantly reduced the incidence of meningitis in this region. MenAfriVac is a conjugate vaccine that provides long-lasting immunity and has the added benefit of reducing carriage of the bacteria, thereby decreasing transmission.

Mass vaccination campaigns in countries within the belt have led to a dramatic decline in the number of meningitis A cases. However, serogroups C, W, and X still pose a significant threat, and efforts are ongoing to develop and distribute vaccines that cover these serogroups as well.

Challenges

Despite the success of vaccination campaigns, the African Meningitis Belt continues to face several challenges in the fight against meningitis. These include the emergence of new serogroups, logistical difficulties in conducting mass vaccination campaigns, and the need for sustained surveillance to detect and respond to outbreaks promptly.

Climate change is also a concern, as changes in temperature and humidity may affect the transmission dynamics of Neisseria meningitidis and potentially expand the geographic range of the meningitis belt.

Conclusion

The African Meningitis Belt remains a region of high risk for meningococcal meningitis. While significant progress has been made in reducing the incidence of disease through vaccination, continued vigilance and investment in prevention and control measures are essential to combat this public health threat.