Estimating transmission intensity for a measles epidemic in Niamey, Niger

lessons for intervention

R. F. Grais, Matthew Joseph Ferrari, C. Dubray, Ottar N. Bjornstad, B. T. Grenfell, A. Djibo, F. Fermon, P. J. Guerin

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

The objective of this study is to estimate the effective reproductive ratio for the 2003-2004 measles epidemic in Niamey, Niger. Using the results of a retrospective and prospective study of reported cases within Niamey during the 2003-2004 epidemic, we estimate the basic reproductive ratio, effective reproductive ratio (RE) and minimal vaccination coverage necessary to avert future epidemics using a recent method allowing for estimation based on the epidemic case series. We provide these estimates for geographic areas within Niamey, thereby identifying neighbourhoods at high risk. The estimated citywide RE was 2.8, considerably lower than previous estimates, which may help explain the long duration of the epidemic. Transmission intensity varied during the course of the epidemic and within different neighbourhoods (RE range: 1.4-4.7). Our results indicate that vaccination coverage in currently susceptible children should be increased by at least 67% (vaccine efficacy 90%) to produce a citywide vaccine coverage of 90%. This research highlights the importance of local differences in vaccination coverage on the potential impact of epidemic control measures. The spatial-temporal spread of the epidemic from district to district in Niamey over 30 weeks suggests that targeted interventions within the city could have an impact.

Original languageEnglish (US)
Pages (from-to)867-873
Number of pages7
JournalTransactions of the Royal Society of Tropical Medicine and Hygiene
Volume100
Issue number9
DOIs
StatePublished - Sep 1 2006

Fingerprint

Niger
Measles
Vaccination
Vaccines
Retrospective Studies
Prospective Studies

All Science Journal Classification (ASJC) codes

  • Parasitology
  • Public Health, Environmental and Occupational Health
  • Infectious Diseases

Cite this

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title = "Estimating transmission intensity for a measles epidemic in Niamey, Niger: lessons for intervention",
abstract = "The objective of this study is to estimate the effective reproductive ratio for the 2003-2004 measles epidemic in Niamey, Niger. Using the results of a retrospective and prospective study of reported cases within Niamey during the 2003-2004 epidemic, we estimate the basic reproductive ratio, effective reproductive ratio (RE) and minimal vaccination coverage necessary to avert future epidemics using a recent method allowing for estimation based on the epidemic case series. We provide these estimates for geographic areas within Niamey, thereby identifying neighbourhoods at high risk. The estimated citywide RE was 2.8, considerably lower than previous estimates, which may help explain the long duration of the epidemic. Transmission intensity varied during the course of the epidemic and within different neighbourhoods (RE range: 1.4-4.7). Our results indicate that vaccination coverage in currently susceptible children should be increased by at least 67{\%} (vaccine efficacy 90{\%}) to produce a citywide vaccine coverage of 90{\%}. This research highlights the importance of local differences in vaccination coverage on the potential impact of epidemic control measures. The spatial-temporal spread of the epidemic from district to district in Niamey over 30 weeks suggests that targeted interventions within the city could have an impact.",
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Estimating transmission intensity for a measles epidemic in Niamey, Niger : lessons for intervention. / Grais, R. F.; Ferrari, Matthew Joseph; Dubray, C.; Bjornstad, Ottar N.; Grenfell, B. T.; Djibo, A.; Fermon, F.; Guerin, P. J.

In: Transactions of the Royal Society of Tropical Medicine and Hygiene, Vol. 100, No. 9, 01.09.2006, p. 867-873.

Research output: Contribution to journalArticle

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