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MICROBIOLOGY IN AFRICA ARTICLE
Antimicrobial testing
for paediatric bacterial
meningitis in Sudan
facilities because a single dose of this
Sudan lies within the so-called meningitis belt that stretches across Africa long-acting formulation has been shown
to be effective.4
from Senegal in the west to Ethiopia in the east. Here, Mahadi Mahmoud
BUGS FROM BRAZIL
and colleagues focus on this devastating bacterial infection in the paediatric The incidence of bacterial meningitis is
higher in developing countries than in
setting in Khartoum. developed countries1–10 and is particularly
high in children under one year old. Mortality
rates for bacterial meningitis range from
Bacterial meningitis is an inflammatory are through direct contact with patients with 4.5% in developed countries to 15–50% in
process of the meninges and is a major meningococcal disease.3 developing countries.5
cause of death and disability worldwide.1 Of the other common pathogens that It has been proposed that clinical efficacy
Meningococcal disease was first described cause paediatric bacterial meningitis, and safety of short-duration regimens of third-
in 1805 when an outbreak occurred in Haemophilus influenzae and Streptococcus generation cephalosporin therapy (ie five days
Geneva, Switzerland. However, the causative pneumoniae are susceptible to penicillin and versus seven days or five days versus 10 days
agent, Neisseria meningitidis, was not cefotaxime.1 A range of antibiotics may be of cefotaxime or ceftriaxone) for bacterial
identified until 1887. Twelve serogroups used for treatment, including penicillin, meningitis should be studied.6,7 In Brazil,
of N. meningitidis have been identified and ampicillin, chloramphenicol and ceftriaxone. antimicrobial susceptibility has been
four (N. meningitidis A, B, C and W 135) In epidemics, oily chloramphenicol is the determined for 150 H. influenzae isolates
have caused epidemics.2 drug of choice in areas with limited health obtained during population-based surveillance
N. meningitidis is a Gram-negative
diplococcus (Fig 1) that possesses capsular
polysaccharide antigens that differentiate
eight serogroups (A, B, C, X, Y, Z, 29-E and
W135). Subtyping identifies certain strains
that are associated with increased virulence
and epidemic potential. The organism can
grow on blood agar and produces haemolytic
colonies. Most cases of N. meningitidis
infection are acquired through exposure to
asymptomatic carriers, while relatively few
‘The incidence of bacterial
meningitis is higher in
developing countries than in
developed countries and is
particularly high in children
under one year old’ Fig 1. Intracellular meningococci in a cerebrospinal fluid sample.
OCTOBER 2008 THE BIOMEDICAL SCIENTIST 893

2. pp893-895 BMSoct08 17/9/08 15:31 Page 894
ARTICLE
for meningitis, and 10 (6.7%) isolates were
resistant to ampicillin and chloramphenicol. 600
Of these, two isolates, a β-lactamase and 500 Cases 2000
non-β-lactamase producer, were resistant to Cases 2001
amoxacillin-clavulanic acid. These findings 400 Cases 2002
Cases
indicate that present antibiotic regimens in 300
Brazil may not be appropriate for the
200
treatment of H. influenzae meningitis.8
100
PENETRATING THE
0
CEREBROSPINAL SPACE
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
Either parenteral penicillin or ampicillin is
the drug of choice, while chloramphenicol is a Weeks
good and inexpensive alternative.9 The third-
generation cephalosporins ceftriaxone and Fig 2. Meningitis cases reported in Sudan (2000–2002).
cefotaxime are excellent alternatives but are
considerably more expensive. On the other Prevalence of paediatric bacterial ‘Other common pathogens
hand, ceftriaxone can be administered once a meningitis in the population studied was
day for as short a period as just two days, 20.4%, and the most common isolated that cause paediatric
which needs to be taken into account when organism was N. meningitidis (78.8%),
comparing the total costs of treatment with followed by H. influenzae (16.4%). The latter bacterial meningitis include
this antibiotic.10 is a common causative agent of paediatric
Worldwide, one million cases of bacterial meningitis in similar studies carried out in Haemophilus influenzae and
meningitis are estimated to occur and the USA, Wales, Australia and Israel, with
200,000 of these are fatal. Meningitis remains H. influenzae isolation rates of 40% , 22%, Streptococcus pneumoniae’
a major public health challenge in the 25% and 18%, respectively.16 Other similar
African ‘meningitis belt’, an area that extends studies have shown H. influenzae rates of
from Senegal to Ethiopia with an estimated 23.8% and 33.8%.17 sulphonate and chloramphenicol resistance
total population of 300 million. Over the last The isolation rate for S. pneumoniae of was 40% and 13, respectively.
10 years some 700,000 cases of epidemic 5.5% in the present study was low compared
meningitis have been reported, and about with other reported rates of 14.3% and 14.8% ACTIVE SURVEILLANCE
10% of patients have died.11 (from Saudi Arabia), and with rates in Most of the isolates show a pattern of resistant
Epidemics in the meningitis belt have been non-meningitis belt countries of 30–50% for most of the commonly used antibiotics,
associated traditionally with serogroup A N. and 25–35%, and N. meningitidis rates which suggests a high rate of misuse of these
meningitidis. In Sudan, many outbreaks have of 25–35%.18–20 Surveillance in Egypt agents. Moreover, the lack of laboratory
occurred over the past years,12 as shown in the (1998–2002)21 shows similar findings to facilities to establish proper isolation,
chart covering the years 2000–2002 (Fig 2). those reported here, with H. influenzae identification and susceptibility testing to
All humans are susceptible to meningitis, rates of 18%; however, infection rate for facilitate diagnosis is a contributing factor.
which has an incubation period that varies S. pneumoniae was high at 37% but for Establishment of a treatment strategy
from one to 10 days (usually <4 days). N. meningitidis was low at 17%. for bacterial meningococcal infection is
Many antimicrobials are active against N. meningitidis showed a pattern required. Surveillance and a vaccination
meningococci in vitro, but only those that of resistance to erythromycin (36.4%), programme should be activated in epidemic
penetrate the cerebrospinal space should chloramphenicol (20.5%), trimethoprim areas, especially for children, and the
be used.13 sulphonate (11.4%) and ceftriaxone (4.7%). development of molecular techniques to
However, these results differed from those detect resistant strains would be helpful.
SEROTYPING TO SUSCEPTABILITY of a similar study performed in Saudi Arabia, Finally, health education is essential through
This study from Sudan aims to evaluate the which shows resistance to chloramphenicol public awareness of meningitis, and also
common causative agents of bacterial at 12.7%, and a Kenyan study that shows an understanding that antimicrobial agents
meningitis in this area of Africa among a resistance at 8%. often are misused. ᔢ
paediatric population, and to study the H. influenzae was resistant to most
pattern of antimicrobial susceptibility testing commonly used antimicrobial agent (ampicillin REFERENCES
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BJBS
A selection of topics
in Volume 65,
Number 4, 2008
• Comparative in vitro antimicrobial procedural efficacy for susceptibility
of Staphylococcus aureus, Escherichia coli and Pseudomonas species
to chloramphenicol, ciprofloxacin and cefaclor
• Correlation of Bmi-1 expression and telomerase activity in human
ovarian cancer
Available online at www.bjbs-online.org
• Effect of cytokines on hyaluronan synthase activity and response
to oxidative stress by fibroblasts
• Molecular characterisation of the recA locus in clinical isolates Reading a
of verocytotoxigenic E. coli O157:H7 colleague’s
• Cloning and structural analysis of full-length cytolethal distending copy of
toxin (cdt) gene operon from Campylobacter lari
• Reduction of Staphylococcus epidermidis adhesion to indwelling
The Biomedical
medical devices: a simple procedure Scientist?
• Antibiotic susceptibility patterns of Helicobacter pylori strains from Join the IBMS
patients with upper gastrointestinal pathology in western Nigeria
and its CPD
• Fluorescence (FISH) and chromogenic (CISH) in situ hybridisation in
prostate carcinoma cell lines: comparison and use of virtual microscopy scheme
• Good analytical practice: statistics and handling data in the biomedical Keep in touch with
sciences. A primer and directions for authors. Part 1: Introduction. your profession and
Data within and between one or two sets of individuals
update your skills
OCTOBER 2008 THE BIOMEDICAL SCIENTIST 885