Journal Article > CommentaryFull Text
PLOS Med. 5 November 2013; Volume 10 (Issue 11); DOI:10.1371/journal.pmed.1001544
Minetti A, Bopp C, Fermon F, Francois G, Grais RF, et al.
PLOS Med. 5 November 2013; Volume 10 (Issue 11); DOI:10.1371/journal.pmed.1001544
Andrea Minetti and colleagues compare measles outbreak responses from the Democratic Republic of the Congo and Malawi and argue that outbreak response strategies should be tailored to local measles epidemiology. Please see later in the article for the Editors' Summary.
Journal Article > ReviewAbstract
Pathog Glob Health. 1 January 2014; Volume 108 (Issue 1); DOI:10.1179/2047773214Y.0000000126
Ali A, Jafri RZ, Messonnier N, Tevi-Benissan C, Durrheim DN, et al.
Pathog Glob Health. 1 January 2014; Volume 108 (Issue 1); DOI:10.1179/2047773214Y.0000000126
A number of countries now include meningococcal vaccines in their routine immunization programs. This review focuses on different approaches to including meningococcal vaccines in country programs across the world and their effect on the burden of invasive meningococcal disease (IMD) as reflected by pre and post-vaccine incidence rates in the last 20 years. Mass campaigns using conjugated meningococcal vaccines have lead to control of serogroup C meningococcal disease in the UK, Canada, Australia, Spain, Belgium, Ireland, and Iceland. Serogroup B disease, predominant in New Zealand, has been dramatically decreased, partly due to the introduction of an outer membrane vesicle (OMV) vaccine. Polysaccharide vaccines were used in high risk people in Saudi Arabia and Syria and in routine immunization in China and Egypt. The highest incidence region of the meningitis belt initiated vaccination with the serogroup A conjugate vaccine in 2010 and catch-up vaccination is ongoing. Overall results of this vaccine introduction are encouraging especially in countries with a moderate to high level of endemic disease. Continued surveillance is required to monitor effectiveness in countries that recently implemented these programs.
Journal Article > ResearchFull Text
Trans R Soc Trop Med Hyg. 1 March 2008; Volume 102 (Issue 3); DOI:10.1016/j.trstmh.2007.10.015
Alberti KP, Guthmann JP, Fermon F, Nargaye KD, Grais RF
Trans R Soc Trop Med Hyg. 1 March 2008; Volume 102 (Issue 3); DOI:10.1016/j.trstmh.2007.10.015
Inadequate evaluation of vaccine coverage after mass vaccination campaigns, such as used in national measles control programmes, can lead to inappropriate public health responses. Overestimation of vaccination coverage may leave populations at risk, whilst underestimation can lead to unnecessary catch-up campaigns. The problem is more complex in large urban areas where vaccination coverage may be heterogeneous and the programme may have to be fine-tuned at the level of geographic subunits. Lack of accurate population figures in many contexts further complicates accurate vaccination coverage estimates. During the evaluation of a mass vaccination campaign carried out in N'Djamena, the capital of Chad, Lot Quality Assurance Sampling was used to estimate vaccination coverage. Using this method, vaccination coverage could be evaluated within smaller geographic areas of the city as well as for the entire city. Despite the lack of accurate population data by neighbourhood, the results of the survey showed heterogeneity of vaccination coverage within the city. These differences would not have been identified using a more traditional method. The results can be used to target areas of low vaccination coverage during follow-up vaccination activities.
Journal Article > ResearchFull Text
Vaccine. 23 September 2014; Volume 32 (Issue 47); DOI:10.1016/j.vaccine.2014.09.027
Juan-Giner A, Domicent C, Langendorf C, Roper M, Baoundoh P, et al.
Vaccine. 23 September 2014; Volume 32 (Issue 47); DOI:10.1016/j.vaccine.2014.09.027
In resource-poor settings, cold chain requirements present barriers for vaccine delivery. We evaluated the immunogenicity and safety of tetanus toxoid (TT) vaccine in "Controlled Temperature Chain" (CTC; up to 40°C for <30 days before administration), compared to standard cold chain (SCC; 2-8°C). Prior to the study, stability parameters of TT-CTC were shown to meet international requirements.
Journal Article > ResearchFull Text
J Infect Dis. 1 July 2011; Volume 204 (Issue suppl_1); DOI:10.1093/infdis/jir093
Luquero FJ, Pham-Orsetti H, Cummings DAT, Ngaunji PE, Nimpa M, et al.
J Infect Dis. 1 July 2011; Volume 204 (Issue suppl_1); DOI:10.1093/infdis/jir093
A measles outbreak occurred in Maroua, Cameroon, from January 2008 to April 2009. In accordance with recent World Health Organization guidelines, an outbreak-response immunization (ORI) was conducted in January 2009. The aim of this study was to investigate the causes of the epidemic in order to guide vaccination strategies.
Journal Article > ResearchFull Text
Trans R Soc Trop Med Hyg. 1 September 2006; Volume 100 (Issue 9); DOI:10.1016/j.trstmh.2005.10.014
Grais RF, Ferrari MJ, Dubray C, Bjørnstad ON, Grenfell BT, et al.
Trans R Soc Trop Med Hyg. 1 September 2006; Volume 100 (Issue 9); DOI:10.1016/j.trstmh.2005.10.014
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.
Journal Article > ResearchFull Text
PLOS Med. 1 January 2007; Volume 4 (Issue 1); DOI:10.1371/journal.pmed.0040016
Grais RF, Dubray C, Gerstl S, Guthmann JP, Djibo A, et al.
PLOS Med. 1 January 2007; Volume 4 (Issue 1); DOI:10.1371/journal.pmed.0040016
BACKGROUND: Despite the comprehensive World Health Organization (WHO)/United Nations Children's Fund (UNICEF) measles mortality-reduction strategy and the Measles Initiative, a partnership of international organizations supporting measles mortality reduction in Africa, certain high-burden countries continue to face recurrent epidemics. To our knowledge, few recent studies have documented measles mortality in sub-Saharan Africa. The objective of our study was to investigate measles mortality in three recent epidemics in Niamey (Niger), N'Djamena (Chad), and Adamawa State (Nigeria). METHODS AND FINDINGS: We conducted three exhaustive household retrospective mortality surveys in one neighbourhood of each of the three affected areas: Boukoki, Niamey, Niger (April 2004, n = 26,795); Moursal, N'Djamena, Chad (June 2005, n = 21,812); and Dong District, Adamawa State, Nigeria (April 2005, n = 16,249), where n is the total surveyed population in each of the respective areas. Study populations included all persons resident for at least 2 wk prior to the study, a duration encompassing the measles incubation period. Heads of households provided information on measles cases, clinical outcomes up to 30 d after rash onset, and health-seeking behaviour during the epidemic. Measles cases and deaths were ascertained using standard WHO surveillance-case definitions. Our main outcome measures were measles attack rates (ARs) and case fatality ratios (CFRs) by age group, and descriptions of measles complications and health-seeking behaviour. Measles ARs were the highest in children under 5 y old (under 5 y): 17.1% in Boukoki, 17.2% in Moursal, and 24.3% in Dong District. CFRs in under 5-y-olds were 4.6%, 4.0%, and 10.8% in Boukoki, Moursal, and Dong District, respectively. In all sites, more than half of measles cases in children aged under 5 y experienced acute respiratory infection and/or diarrhoea in the 30 d following rash onset. Of measles cases, it was reported that 85.7% (979/1,142) of patients visited a health-care facility within 30 d after rash onset in Boukoki, 73.5% (519/706) in Moursal, and 52.8% (603/1,142) in Dong District. CONCLUSIONS: Children in these countries still face unacceptably high mortality from a completely preventable disease. While the successes of measles mortality-reduction strategies and progress observed in measles control in other countries of the region are laudable and evident, they should not overshadow the need for intensive efforts in countries that have just begun implementation of the WHO/UNICEF comprehensive strategy.
Journal Article > ResearchFull Text
BMC Public Health. 21 February 2014; Volume 14; DOI:10.1186/1471-2458-14-193
Grout L, Conan N, Giner AJ, Hurtado N, Fermon F, et al.
BMC Public Health. 21 February 2014; Volume 14; DOI:10.1186/1471-2458-14-193
Background: The World Health Organization recommends African children receive two doses of measles containing vaccine (MCV) through routine programs or supplemental immunization activities (SIA). Moreover, children have an additional opportunity to receive MCV through outbreak response immunization (ORI) mass campaigns in certain contexts. Here, we present the results of MCV coverage by dose estimated through surveys conducted after outbreak response in diverse settings in Sub-Saharan Africa.
Methods: We included 24 household-based surveys conducted in six countries after a non-selective mass vaccination campaign. In the majority (22/24), the survey sample was selected using probability proportional to size cluster-based sampling. Others used Lot Quality Assurance Sampling.
Results: In total, data were collected on 60,895 children from 2005 to 2011. Routine coverage varied between countries (>95% in Malawi and Kirundo province (Burundi) while <35% in N'Djamena (Chad) in 2005), within a country and over time. SIA coverage was <75% in most settings. ORI coverage ranged from >95% in Malawi to 71.4% [95% CI: 68.9-73.8] in N'Djamena (Chad) in 2005.In five sites, >5% of children remained unvaccinated after several opportunities. Conversely, in Malawi and DRC, over half of the children eligible for the last SIA received a third dose of MCV.
Conclusions: Control pre-elimination targets were still not reached, contributing to the occurrence of repeated measles outbreak in the Sub-Saharan African countries reported here. Although children receiving a dose of MCV through outbreak response benefit from the intervention, ensuring that programs effectively target hard to reach children remains the cornerstone of measles control.
Methods: We included 24 household-based surveys conducted in six countries after a non-selective mass vaccination campaign. In the majority (22/24), the survey sample was selected using probability proportional to size cluster-based sampling. Others used Lot Quality Assurance Sampling.
Results: In total, data were collected on 60,895 children from 2005 to 2011. Routine coverage varied between countries (>95% in Malawi and Kirundo province (Burundi) while <35% in N'Djamena (Chad) in 2005), within a country and over time. SIA coverage was <75% in most settings. ORI coverage ranged from >95% in Malawi to 71.4% [95% CI: 68.9-73.8] in N'Djamena (Chad) in 2005.In five sites, >5% of children remained unvaccinated after several opportunities. Conversely, in Malawi and DRC, over half of the children eligible for the last SIA received a third dose of MCV.
Conclusions: Control pre-elimination targets were still not reached, contributing to the occurrence of repeated measles outbreak in the Sub-Saharan African countries reported here. Although children receiving a dose of MCV through outbreak response benefit from the intervention, ensuring that programs effectively target hard to reach children remains the cornerstone of measles control.
Journal Article > ResearchAbstract
Int Health. 11 November 2011; Volume 3 (Issue 4); DOI:10.1016/j.inhe.2011.06.003
Guerrier G, Guerra J, Fermon F, Talkibing WB, Sekkenes J, et al.
Int Health. 11 November 2011; Volume 3 (Issue 4); DOI:10.1016/j.inhe.2011.06.003
Journal Article > Short ReportFull Text
Emerg Infect Dis. 1 January 2015; Volume 21 (Issue 1); DOI:10.3201/eid2101.140256
Gamougam K, Daugla DM, Toralta J, Ngadoua C, Fermon F, et al.
Emerg Infect Dis. 1 January 2015; Volume 21 (Issue 1); DOI:10.3201/eid2101.140256
In 2011, vaccination with a serogroup A meningococcal polysaccharide conjugate vaccine was implemented in 3 of 23 regions in Chad. Cases of meningitis declined dramatically in vaccinated areas, but an epidemic continued in the rest of Chad. In 2012, the remaining Chad population was vaccinated, and the epidemic was halted.