A newly developed meningococcal A conjugate vaccine led to a decrease in the number of meningitis cases in Sudan, the only country in the Region in the so-called meningitis belt (Photo: Pixabay)
Meningococcal diseases
Meningococcal diseases include meningococcal meningitis (see below) and meningococcaemia (also known as meningococcal septicaemia), which is an infection of the blood. Both diseases are caused by the bacterium Neisseria Meningitidis (more commonly known as meningococcus), although meningitis has additional nonbacterial causes (see below).
Symptoms of meningococcaemia range from milder, like fever, headache, and rashes consisting of small spots, to more severe ones like blood clotting, patches of subcutaneous bleeding, lethargy and shock. The infection may also spread through the body and cause meningitis, and must be treated immediately with antibiotics.
Meningitis
Meningitis is a life-threatening infection of the meninges (the three membranes that envelop the brain and spinal cord) that affects the brain and spinal cord. It is usually caused by infection with meningococcus, which is transmitted only from person to person through droplets of respiratory or throat secretions. Additional causes of meningitis include fungal infection, chemical irritation, bleeding into the subarachnoid space surrounding the brain, and cancer. Smoking and close and prolonged contact with infected persons, as well as mass gatherings, such as the Haj pilgrimage, facilitate the spread of meningococcal meningitis.
The most common symptoms of meningitis are a stiff neck, high fever, sensitivity to light, confusion, headaches and vomiting. If left untreated, the disease kills up to 50% of those infected. More than 10% of patients will develop severe conditions such as hearing loss, cognitive impairment and epilepsy. Even when the disease is diagnosed early and adequate treatment is started, 5-10% of patients die, typically within 24 to 48 hours after the onset of symptoms.
Meningococcal meningitis is of particular importance due to its potential to cause large epidemics. Twelve types of N. meningitides have been identified, six of which (A, B, C, W, X and Y) can cause epidemics.
The largest disease burden occurs in an area of sub-Saharan Africa known as the meningitis belt, which stretches from Senegal and the Gambia in West Africa to Ethiopia in the East and includes 26 countries in total. Sudan is the only country in the Region included in those, and major epidemics have been reported from Sudan in 1950–1951, 1978–1979, 1988–1989, and in 1998–1999. The Hajj pilgrimage in Saudi Arabia has been associated with two major outbreaks of meningococcal meningitis caused by N. meningitidis serogroups A and W135, resulting in the global dissemination of meningococcal disease in 1987 and also in 2000 respectively. As such, the current Hajj vaccination policy includes mandatory vaccination for all pilgrims by polysaccharide quadrivalent ACWY vaccines.
The progressive introduction of a newly developed meningococcal A conjugate vaccine in 2012 led to a decrease in the number of cases, and mass preventive vaccination campaigns were successfully implemented throughout Sudan in 2013. In 2016, this meningitis A vaccination was introduced into the country’s routine immunization programme.
In addition to preventive vaccination, other preventive and control measures include enhanced surveillance, early confirmation of outbreaks, case management, and reactive vaccination. After infection, appropriate antibiotic treatment, which may include penicillin, ampicillin and ceftriaxone, should be started as soon as possible.
