Neisseria meningitidis nasopharynx colonization of diseased patients on presentation and on discharge

Carriage of Neisseria Meningitidis in Low and Middle Income Countries of the Americas and Asia: A Review of the Literature

INTRODUCTION

Meningococcal colonization, or carriage, can progress to invasive meningococcal disease, a serious public health concern, with rapid progression of disease and severe consequences if left untreated. Information on meningococcal carriage and epidemiology in low/middle income American and Asian countries remains sparse. These data are crucial to ensure that appropriate preventive strategies such as vaccination can be implemented in these regions. The goal of this study was to summarize the Neisseria meningitidis carriage literature in low and middle income countries of the Americas and Asia.

METHODS

Target countries were categorized as low and middle income according to the International Monetary Fund classification of low income/developing economies and middle income/emerging market economies, respectively. A PubMed search identified English-language publications that examined carriage in these countries. Studies reporting the epidemiology of N. meningitidis carriage or assessing risk factors for carriage were included.

RESULTS

Fourteen studies from the Americas [Brazil (n = 7), Chile (n = 3), and Colombia, Cuba, Mexico, and Paraguay (n = 1 each)] and nine from Asia [China (n = 2), India (n = 3), and Malaysia, Nepal, Philippines, and Thailand (n = 1 each)] were identified; an additional Cuban study from the authors' files was also included. Studies were not identified in many target countries, and substantial diversity was observed among study methodologies, populations, and time periods, thereby limiting comparison between studies. The carriage rate in the Americas ranged from 1.6% to 9.9% and from 1.4% to 14.2% in Asia. Consistent risk factors for carriage were not identified.

CONCLUSIONS

There is a lack of comprehensive and contemporary information on meningococcal carriage in low and medium income countries of the Americas and Asia. Future carriage studies should incorporate larger representative populations, a wider age range, and additional countries to improve our understanding of meningococcal epidemiology and disease control.

Effectiveness of antibiotics in preventing meningococcal disease after a case: systematic review

OBJECTIVE

To summarise the evidence for the role of antibiotics in preventing further cases of meningococcal disease through chemoprophylaxis given to the index patient, household contacts, and children in day care settings after a single case.

DESIGN

Systematic review.

METHODS

Studies were identified by searching Embase (1983-2003), Medline (1965-2003), and CAB Health (1973-2003) and by contacting the World Health Organization and the European meningococcal disease surveillance network and examining references of identified papers. The review included all studies with at least 10 cases in which outcomes were compared between treated and untreated groups.

MAIN OUTCOME MEASURE

Subsequent cases of meningococcal disease 1-30 days after onset of disease in the index patient.

RESULTS

Four observational studies and one small trial met the inclusion criteria. Meta-analysis of studies on chemoprophylaxis given to household contacts showed a significant reduction in risk (risk ratio 0.11, 95% confidence interval 0.02 to 0.58). The number needed to treat to prevent a case was estimated as 218 (121 to 1135). Primary outcome data were not available in studies of chemoprophylaxis given to the index patient: when prophylaxis had not been given, rate of carriage after discharge from hospital was estimated as 3% (0 to 6), probably an underestimate of the true rate. No studies of chemoprophylaxis in day care settings were identified that met the inclusion criteria.

CONCLUSION

There have been no high quality experimental trials looking at control policies for meningococcal disease. The best available evidence is from retrospective studies. The risk of meningococcal disease in household contacts of a patient can be reduced by an estimated 89% if they take antibiotics known to eradicate meningococcal carriage. Chemoprophylaxis should be recommended for the index patient and all household contacts.