The only natural reservoir of Neisseria meningitidis is the human nasopharyngeal mucosa. Depending on age, climate, country, socioeconomic status, and other factors, approximately 10% of the human population harbors meningococci in the nose. However, invasive disease is relatively rare, as it occurs only when the following conditions are fulfilled: (i) contact with a virulent strain, (ii) colonization by that strain, (iii) penetration of the bacterium through the mucosa, and (iv) survival and eventually outgrowth of the meningococcus in the bloodstream. When the meningococcus has reached the bloodstream and specific antibodies are absent, as is the case for young children or after introduction of a new strain in a population, the ultimate outgrowth depends on the efficacy of the innate immune response. Massive outgrowth leads within 12 h to fulminant meningococcal sepsis (FMS), characterized by high intravascular concentrations of endotoxin that set free high concentrations of proinflammatory mediators. These mediators belonging to the complement system, the contact system, the fibrinolytic system, and the cytokine system induce shock and diffuse intravascular coagulation. FMS can be fatal within 24 h, often before signs of meningitis have developed. In spite of the increasing possibilities for treatment in intensive care units, the mortality rate of FMS is still 30%. When the outgrowth of meningococci in the bloodstream is impeded, seeding of bacteria in the subarachnoidal compartment may lead to overt meningitis within 24 to 36 h. With appropriate antibiotics and good clinical surveillance, the mortality rate of this form of invasive disease is 1 to 2%. The overall mortality rate of meningococcal disease can only be reduced when patients without meningitis, i.e., those who may develop FMS, are recognized early. This means that the fundamental nature of the disease as a meningococcus septicemia deserves more attention.

Update on Meningococcal Disease with Emphasis on Pathogenesis and Clinical Management

This review covers the history of meningococcal meningitis in Africa since epidemics of the infection were first described around 100 years ago. It is possible that an epidemic strain of the meningococcus was introduced into West Africa from the Sudan by pilgrims returning from the Haj around the turn of the century. Since 1905 major epidemics of meningococcal meningitis have occurred in countries of the Sahel and sub-Sahel every few years, culminating in a massive epidemic in which nearly 200,000 cases were reported in 1996. Attempts to control epidemic meningococcal meningitis in Africa by vaccination with meningococcal polysaccharide vaccines have met with only modest success because epidemics can progress with great rapidity and vaccination is often started too late. This situation should be improved as a result of a recent initiative, the International Coordinating Group (ICG), which is contributing to better surveillance in countries at risk and ensuring that vaccine is available when needed. However, in the medium term, the best prospect for the control of meningococcal meningitis in Africa lies in the recent development of polysaccharide-protein conjugate vaccines which, unlike polysaccharide vaccines, are immunogenic in the very young, induce immunological memory and are likely to give long-lasting protection.

Manson Lecture. Meningococcal meningitis in Africa.

In developing countries, endemic childhood meningitis is a severe disease caused most commonly by Streptococcus pneumoniae or Haemophilus influenzae type b (Hib). Although many studies have shown that fatality rates associated with meningitis caused by these organisms are high in developing countries, little is known about the long-term outcome of survivors. The purpose of this study was to assess the importance of disabilities following pneumococcal and Hib meningitis in The Gambia. 257 children aged 0-12 years hospitalized between 1990 and 1995 with culture-proven S. pneumoniae (n = 134) or Hib (n = 123) meningitis were included retrospectively in the study. 48% of children with pneumococcal meningitis and 27% of children with Hib meningitis died whilst in hospital. Of the 160 survivors, 89 (55%) were followed up between September 1996 and October 1997. Of the children with pneumococcal meningitis that were traced, 58% had clinical sequelae; half of them had major disabilities preventing normal adaptation to social life. 38% of survivors of Hib meningitis had clinical sequelae, a quarter of whom had major disabilities. Major handicaps found were hearing loss, mental retardation, motor abnormalities and seizures. These data show that despite treatment with effective antibiotics, pneumococcal and Hib meningitis kill many Gambian children and leave many survivors with severe sequelae. Hib vaccination is now given routinely in The Gambia; an effective pneumococcal vaccine is needed.

Outcome of meningitis caused by Streptococcus pneumoniae and Haemophilus influenzae type b in children in The Gambia.

Sarcoptes scabiei and scabies

In order to estimate the importance as a public health problem of skin diseases, we investigated the prevalence and severity of skin diseases in a representative sample of children in Mali. 1817 children were randomly selected in 30 clusters by probability-proportional-to-size sampling in Koulikoro region. The mean prevalence (+/- 2 SD) of skin diseases was 34 +/- 4%. The most frequent dermatoses were pyoderma (12.3 +/- 1.6%), tinea capitis (9.5 +/- 2.5%), pediculosis capitis (4.7 +/- 1.4%), scabies (4.3 +/- 1.5%), and molluscum contagiosum (3.6 +/- 1%). The most troublesome dermatoses were scabies and severe pyoderma. Pyoderma was the only dermatosis associated with poor individual or household hygiene. Public health services were little used by the population for skin diseases, probably because of the lack of an adequate response by the services and the high cost of treatment. The high prevalence and the severity of many of the lesions, and the discomfort caused, make pyoderma and scabies a significant public health problem in Mali.

Skin diseases of children in Mali: a public health problem

In a controlled trial chloramphenicol proved as effective and much cheaper than penicillin for the treatment of group A meningococcal meningitis in Zaria, Nigeria. A short course of five days cured most patients. Adults and older children were soon able to take chloramphenicol by mouth, which reduced the cost and simplified treatment.It is suggested that chloramphenicol is a suitable alternative to sulphonamides for the treatment of meningococcal meningitis in those parts of Africa where the organism is sulphonamide-resistant.

https://www.bmj.com/content/bmj/3/5876/379.full.pdf

Trial of chloramphenicol for meningitis in northern savanna of Africa.

Meningococcal antigen in diagnosis and treatment of group A meningococcal infections.

The epidemiology and clinical features of skin rashes, pyoderma, and pyoderma with nephritis in children and adults in Zaria is described. Scabies is endemic in Zaria especially among young children, and boys at the Koranic schools. Pyoderma follows secondary infection of scabies and is more prevalent towards the end of the humid rainy season in August and September. Acute glomerulo-nephritis is common at this time also. Of 20 patients with pyoderma and nephritis 16 had scabies which had become infected. Group A streptococci were isolated from the skin lesions of 11 patients, but only 2 strains—one each of types M49 and M55—recognized to be associated with nephritis, were recovered. 3 patients had an uncommon type, M26 which had not previously been suspected of causing nephritis. Serum complement was low in all 10 patients with nephritis who were tested. Anti-deoxyribonuclease B was significantly more useful as an index of streptococcal infection than the antistreptolysin 0 titre.

A.D. Rajkovic

Papers

Trial of chloramphenicol for meningitis in northern savanna of Africa.

Meningococcal antigen in diagnosis and treatment of group A meningococcal infections.

Scabies, pyoderma and nephritis in Zaria, Nigeria. A clinical and epidemiological study