TY - JOUR
T1 - Estimating transmission intensity for a measles epidemic in Niamey, Niger
T2 - lessons for intervention
AU - Grais, R. F.
AU - Ferrari, M. J.
AU - Dubray, C.
AU - Bjørnstad, O. N.
AU - Grenfell, B. T.
AU - Djibo, A.
AU - Fermon, F.
AU - Guerin, P. J.
N1 - Funding Information:
This research work was supported by MSF and WHO. M.J.F., O.N.B. and B.T.G. received funding from the Fogarty International Center, National Institutes of Health, USA for their participation. We thank the Ministry of Health of Niger for their support during the outbreak investigations. We also thank the MSF team in Niger for their committed work during this outbreak. In Niger, several individuals were key to the collection of the data used in this analysis: Dr Abdulaye Djibo (MSF), who was in charge of data collection for the entire epidemic; Moussa Mallam Barke (epidemiologist at the DRSP, MoH), who was of a great help in providing data and his valuable insight on the measles situation in Niger; Dr Ibrahim Chaibou, head of the Epidemiology department, Institut de Santé Publique (ISP), and Mr Sanda Maiga Abdullaye, Director of the Institut Pratique de Santé Publique (IPSP), who provided public health students for the LQAS survey and for retrospective and prospective data collection. A special thanks to students from the ISP and the IPSP for collecting data under difficult conditions. We also wish to thank Dr Alan Moren for his continued support. This work is dedicated to the memory of Nicholas Nathan.
PY - 2006/9
Y1 - 2006/9
N2 - 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.
AB - 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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U2 - 10.1016/j.trstmh.2005.10.014
DO - 10.1016/j.trstmh.2005.10.014
M3 - Article
C2 - 16540134
AN - SCOPUS:33745623952
SN - 0035-9203
VL - 100
SP - 867
EP - 873
JO - Transactions of the Royal Society of Tropical Medicine and Hygiene
JF - Transactions of the Royal Society of Tropical Medicine and Hygiene
IS - 9
ER -
