Microbiological and epidemiological investigation of the <i>Neisseria meningitidis</i> serogroup A epidemic in Niger in 2009: last wave before the introduction of the serogroup A meningococcal conjugate vaccine?

Collard, Jean-Marc; Maman, Z.; Abani, A.; Mainasara, H. B.; Djibo, S.; Yacouba, Harouna; Maitournam, R.; Sidikou, Fati; Nicolas, Pierre; Rocourt, J.; Jusot, Jean-François

doi:10.1017/s0950268810003092

Cited by 8 publications

(8 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8 The age distribution of NmC cases, with the highest proportions observed in adolescents and young adults, is similar to that reported in previous NmA epidemics, 22 whereas the predominance of NmW cases in children younger than 5 years has been reported in other NmW epidemics. 4,6 The overall case fatality rate of 5·9% in this NmC epidemic is consistent with that reported in several NmA, NmW, and NmX epidemics in Niger (roughly 4–8%), 4,8,21–23 although the incompleteness of case outcome in the surveillance data limits the interpretation of these results.…”

Section: Discussionsupporting

confidence: 88%

“…Although the NmC epidemic did not match the magnitude of the largest NmA epidemics in Niger (eg, the 2009 epidemic with nearly 14 000 cases reported), 21 greater numbers of cases were reported during the NmC epidemic (9367 total cases) than in the 2010 mixed NmA–NmW epidemic (nearly 3000 total cases 4 ) and the 2006 mixed NmA–NmX epidemic (more than 4000 total cases). 8 The age distribution of NmC cases, with the highest proportions observed in adolescents and young adults, is similar to that reported in previous NmA epidemics, 22 whereas the predominance of NmW cases in children younger than 5 years has been reported in other NmW epidemics.…”

Section: Discussionmentioning

confidence: 85%

See 1 more Smart Citation

Emergence of epidemic Neisseria meningitidis serogroup C in Niger, 2015: an analysis of national surveillance data

Sidikou

Zaneidou²,

Alkassoum³

et al. 2016

The Lancet Infectious Diseases

View full text Add to dashboard Cite

Summary Background To combat Neisseria meningitidis serogroup A epidemics in the meningitis belt of sub-Saharan Africa, a meningococcal serogroup A conjugate vaccine (MACV) has been progressively rolled out since 2010. We report the first meningitis epidemic in Niger since the nationwide introduction of MACV. Methods We compiled and analysed nationwide case-based meningitis surveillance data in Niger. Cases were confirmed by culture or direct real-time PCR, or both, of cerebrospinal fluid specimens, and whole-genome sequencing was used to characterise isolates. Information on vaccination campaigns was collected by the Niger Ministry of Health and WHO. Findings From Jan 1 to June 30, 2015, 9367 suspected meningitis cases and 549 deaths were reported in Niger. Among 4301 cerebrospinal fluid specimens tested, 1603 (37·3%) were positive for a bacterial pathogen, including 1147 (71·5%) that were positive for N meningitidis serogroup C (NmC). Whole-genome sequencing of 77 NmC isolates revealed the strain to be ST-10217. Although vaccination campaigns were limited in scope because of a global vaccine shortage, 1·4 million people were vaccinated from March to June, 2015. Interpretation This epidemic represents the largest global NmC outbreak so far and shows the continued threat of N meningitidis in sub-Saharan Africa. The risk of further regional expansion of this novel clone highlights the need for continued strengthening of case-based surveillance. The availability of an affordable, multivalent conjugate vaccine may be important in future epidemic response.

show abstract

Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 85%

Emergence of epidemic Neisseria meningitidis serogroup C in Niger, 2015: an analysis of national surveillance data

Sidikou

Zaneidou²,

Alkassoum³

et al. 2016

The Lancet Infectious Diseases

View full text Add to dashboard Cite

show abstract

“…Saharan dust, carried by the Harmattan, has been shown previously to affect health, particularly by exacerbating asthma and favoring the establishment of respiratory tract infections,25, 26, 27 and is thought to have contributed to meningitis outbreaks in Burkina Faso and Niger 3 . Previous studies have demonstrated that uptake of particulates by macrophages can disrupt phagocytic bacterial killing, 28 and we demonstrate here that dust-exposed phagocytes (both macrophages and neutrophils) are functionally impaired.…”

Section: Discussionsupporting

confidence: 49%

“…Neisseria meningitidis serogroups A and X and Streptococcus pneumoniae are the main causative agents 3, 4. Meningitis outbreaks in Niger show strong seasonality, suggesting climatic factors could play a role in disease mechanisms,5, 6, 7, 8, 9, 10 but these studies focus on all-cause meningitis, and little is known about the specific effect of climate on bacterial meningitis.…”

mentioning

confidence: 99%

Airborne dust and high temperatures are risk factors for invasive bacterial disease

Jusot

Neill

Waters

et al. 2017

Journal of Allergy and Clinical Immunology

View full text Add to dashboard Cite

BackgroundThe Sahel region of West Africa has the highest bacterial meningitis attack and case fatality rate in the world. The effect of climatic factors on patterns of invasive respiratory bacterial disease is not well documented.ObjectiveWe aimed to assess the link between climatic factors and occurrence of invasive respiratory bacterial disease in a Sahel region of Niger.MethodsWe conducted daily disease surveillance and climatic monitoring over an 8-year period between January 1, 2003, and December 31, 2010, in Niamey, Niger, to determine risk factors for bacterial meningitis and invasive bacterial disease. We investigated the mechanistic effects of these factors on Streptococcus pneumoniae infection in mice.ResultsHigh temperatures and low visibility (resulting from high concentrations of airborne dust) were identified as significant risk factors for bacterial meningitis. Dust inhalation or exposure to high temperatures promoted progression of stable asymptomatic pneumococcal nasopharyngeal carriage to pneumonia and invasive disease. Dust exposure significantly reduced phagocyte-mediated bacterial killing, and exposure to high temperatures increased release of the key pneumococcal toxin pneumolysin through increased bacterial autolysis.ConclusionOur findings show that climatic factors can have a substantial influence on infectious disease patterns, altering density of pneumococcal nasopharyngeal carriage, reducing phagocytic killing, and resulting in increased inflammation and tissue damage and consequent invasiveness. Climatic surveillance should be used to forecast invasive bacterial disease epidemics, and simple control measures to reduce particulate inhalation might reduce the incidence of invasive bacterial disease in regions of the world exposed to high temperatures and increased airborne dust.

show abstract

“…Although the number of strains typed by MLST in our study was relatively low due to logistic constraints, and this could introduce a bias, we believe that our MLST results provide a reasonably representative picture of the different ST circulating during the epidemic seasons. Between 1995 and 1998, all Nm A isolates from Niger typed by MLST belonged to ST-5, from 1999 to 2001 to ST-7 (differing from ST-5 only at the pgm locus) [17], and from 2002 most of the isolates were ST-7 [18,19]. Serogoup A meningococci are largely clonal and all African isolates typed by the WHO Collaborating Centers for Reference and Research on Meningococci were remarkably homogeneous in their PorA (P1.20,9) and FetA (F3-1) sequences [20].…”

Section: Discussionmentioning

confidence: 99%

Epidemiological changes in meningococcal meningitis in Niger from 2008 to 2011 and the impact of vaccination

Collard

Issaka

Zaneidou³

et al. 2013

BMC Infect Dis

View full text Add to dashboard Cite

BackgroundThe epidemiology of bacterial meningitis in the African ‘meningitis belt’ changes periodically. In order to design an effective vaccination strategy, we have examined the epidemiological and microbiological patterns of bacterial meningitis, and especially that of meningococcal meningitis, in Niger during the period 2008–2011. During this period a mass vaccination campaign with the newly developed meningococcal A conjugate vaccine (MenAfriVac®) was undertaken.MethodCerebrospinal fluid samples were collected from health facilities throughout Niger and analysed by culture, seroagglutination and/or speciation polymerase chain reaction, followed by genogrouping PCR for Neisseria meningitidis infections. A sample of strains were analysed by multi-locus sequence typing.ResultsN. meningitidis serogroup A cases were prevalent in 2008 and 2009 [98.6% and 97.5% of all N. meningitidis cases respectively]. The prevalence of serogroup A declined in 2010 [26.4%], with the emergence of serogroup W Sequence Type (ST) 11 [72.2% of cases], and the serogroup A meningococcus finally disappeared in 2011. The geographical distribution of cases N. meningitidis serogroups A and W within Niger is described.ConclusionThe substantial decline of serogroup A cases that has been observed from 2010 onwards in Niger seems to be due to several factors including a major polysaccharide A/C vaccination campaign in 2009, the introduction of MenAfriVac® in 10 districts at risk in December 2010, the natural dynamics of meningococcal infection and the persistence of serogroup A sequence-type 7 for about 10 years. The emergence of serogroup W strains suggests that there may be a need for serogroup W containing vaccines in Niger in the coming years.

show abstract

Microbiological and epidemiological investigation of the Neisseria meningitidis serogroup A epidemic in Niger in 2009: last wave before the introduction of the serogroup A meningococcal conjugate vaccine?

Cited by 8 publications

References 9 publications

Emergence of epidemic Neisseria meningitidis serogroup C in Niger, 2015: an analysis of national surveillance data

Emergence of epidemic Neisseria meningitidis serogroup C in Niger, 2015: an analysis of national surveillance data

Airborne dust and high temperatures are risk factors for invasive bacterial disease

Epidemiological changes in meningococcal meningitis in Niger from 2008 to 2011 and the impact of vaccination

Contact Info

Product

Resources

About