Mbaye Salla - Academia.edu (original) (raw)

Papers by Mbaye Salla

Journal of Infectious Diseases, 2014

The first steps (phase 1) toward laboratory containment of poliovirus after eradication are a nat... more The first steps (phase 1) toward laboratory containment of poliovirus after eradication are a national survey of biomedical facilities and a global inventory of such facilities retaining wild poliovirus (WPV) infectious and potentially infectious materials. We reviewed published reports on national laboratory surveys and inventories of WPV materials from each of the 3 polio-free World Health Organization (WHO) regions (the European Region, completed in 2006; the Western Pacific Region, completed in 2008; and the Region of the Americas, completed in 2010), as well as reports on progress in polio-free countries of the remaining 3 regions (the African Region, the Eastern Mediterranean Region, and the WHO South-East Asia Region). Containment phase 1 activities are complete in 154 of 194 WHO Member States (79%), including all countries and areas of the polio-free regions and most polio-free countries in the remaining 3 regions. A reported 227 209 biomedical facilities were surveyed, with 532 facilities in 45 countries identified as retaining WPV-associated infectious or potentially infectious materials. Completion of containment phase 1 global activities is achievable within the time frame set by the Polio Eradication and Endgame Strategic Plan 2013-2018.

Vaccine, 2014

This is a comparative analysis of independent monitoring data collected between 2010 and 2012, fo... more This is a comparative analysis of independent monitoring data collected between 2010 and 2012, following the implementation of supplementary immunization activities (SIAs) in countries in the three sub regional blocs of World Health Organization in the African Region. The sub regional blocs are Central Africa, West Africa, East and Southern Africa. In addition to the support for SIAs, the Central and West African blocs, threatened with importation and re-establishment of polio transmission received intensive coordination through weekly teleconferences. The later, East and Southern African bloc with low polio threats was not engaged in the intensive coordination through teleconferences. The key indicator of the success of SIAs is the proportion of children missed during SIAs. The results showed that generally there was a decrease in the proportion of children missed during SIAs in the region, from 7.94% in 2010 to 5.95% in 2012. However, the decrease was mainly in the Central and West African blocs. The East and Southern African bloc had countries with as much as 25% missed children. In West Africa and Central Africa, where more coordinated SIAs were conducted, there were progressive and consistent drops, from close to 20-10% at the maximum. At the country and local levels, steps were undertaken to ameliorate situation of low immunization uptake. Wherever an area is observed to have low coverage, local investigations were conducted to understand reasons for low coverage, plans to improve coverage are made and implemented in a coordinated manner. Lessons learned from close monitoring of polio eradication SIAs are will be applied to other campaigns being conducted in the African Region to accelerate control of other vaccine preventable diseases including cerebrospinal meningitis A, measles and yellow fever.

Risk Analysis, 2013

While global polio eradication requires tremendous efforts in countries where wild polioviruses (... more While global polio eradication requires tremendous efforts in countries where wild polioviruses (WPVs) circulate, numerous outbreaks have occurred following WPV importation into previously polio-free countries. Countries that have interrupted endemic WPV transmission should continue to conduct routine risk assessments and implement mitigation activities to maintain their polio-free status as long as wild poliovirus circulates anywhere in the world. This article reviews the methods used by World Health Organization (WHO) regional offices to qualitatively assess risk of WPV outbreaks following an importation. We describe the strengths and weaknesses of various risk assessment approaches, and opportunities to harmonize approaches. These qualitative assessments broadly categorize risk as high, medium, or low using available national information related to susceptibility, the ability to rapidly detect WPV, and other population or program factors that influence transmission, which the regions characterize using polio vaccination coverage, surveillance data, and other indicators (e.g., sanitation), respectively. Data quality and adequacy represent a challenge in all regions. WHO regions differ with respect to the methods, processes, cut-off values, and weighting used, which limits comparisons of risk assessment results among regions. Ongoing evaluation of indicators within regions and further harmonization of methods between regions are needed to effectively plan risk mitigation activities in a setting of finite resources for funding and continued WPV circulation.

Clinical Infectious Diseases, 2012

Journal of Infectious Diseases, 2014

Journal of Infectious Diseases, 2014

The first steps (phase 1) toward laboratory containment of poliovirus after eradication are a nat... more The first steps (phase 1) toward laboratory containment of poliovirus after eradication are a national survey of biomedical facilities and a global inventory of such facilities retaining wild poliovirus (WPV) infectious and potentially infectious materials. We reviewed published reports on national laboratory surveys and inventories of WPV materials from each of the 3 polio-free World Health Organization (WHO) regions (the European Region, completed in 2006; the Western Pacific Region, completed in 2008; and the Region of the Americas, completed in 2010), as well as reports on progress in polio-free countries of the remaining 3 regions (the African Region, the Eastern Mediterranean Region, and the WHO South-East Asia Region). Containment phase 1 activities are complete in 154 of 194 WHO Member States (79%), including all countries and areas of the polio-free regions and most polio-free countries in the remaining 3 regions. A reported 227 209 biomedical facilities were surveyed, with 532 facilities in 45 countries identified as retaining WPV-associated infectious or potentially infectious materials. Completion of containment phase 1 global activities is achievable within the time frame set by the Polio Eradication and Endgame Strategic Plan 2013-2018.

Vaccine, 2014

This is a comparative analysis of independent monitoring data collected between 2010 and 2012, fo... more This is a comparative analysis of independent monitoring data collected between 2010 and 2012, following the implementation of supplementary immunization activities (SIAs) in countries in the three sub regional blocs of World Health Organization in the African Region. The sub regional blocs are Central Africa, West Africa, East and Southern Africa. In addition to the support for SIAs, the Central and West African blocs, threatened with importation and re-establishment of polio transmission received intensive coordination through weekly teleconferences. The later, East and Southern African bloc with low polio threats was not engaged in the intensive coordination through teleconferences. The key indicator of the success of SIAs is the proportion of children missed during SIAs. The results showed that generally there was a decrease in the proportion of children missed during SIAs in the region, from 7.94% in 2010 to 5.95% in 2012. However, the decrease was mainly in the Central and West African blocs. The East and Southern African bloc had countries with as much as 25% missed children. In West Africa and Central Africa, where more coordinated SIAs were conducted, there were progressive and consistent drops, from close to 20-10% at the maximum. At the country and local levels, steps were undertaken to ameliorate situation of low immunization uptake. Wherever an area is observed to have low coverage, local investigations were conducted to understand reasons for low coverage, plans to improve coverage are made and implemented in a coordinated manner. Lessons learned from close monitoring of polio eradication SIAs are will be applied to other campaigns being conducted in the African Region to accelerate control of other vaccine preventable diseases including cerebrospinal meningitis A, measles and yellow fever.

Risk Analysis, 2013

While global polio eradication requires tremendous efforts in countries where wild polioviruses (... more While global polio eradication requires tremendous efforts in countries where wild polioviruses (WPVs) circulate, numerous outbreaks have occurred following WPV importation into previously polio-free countries. Countries that have interrupted endemic WPV transmission should continue to conduct routine risk assessments and implement mitigation activities to maintain their polio-free status as long as wild poliovirus circulates anywhere in the world. This article reviews the methods used by World Health Organization (WHO) regional offices to qualitatively assess risk of WPV outbreaks following an importation. We describe the strengths and weaknesses of various risk assessment approaches, and opportunities to harmonize approaches. These qualitative assessments broadly categorize risk as high, medium, or low using available national information related to susceptibility, the ability to rapidly detect WPV, and other population or program factors that influence transmission, which the regions characterize using polio vaccination coverage, surveillance data, and other indicators (e.g., sanitation), respectively. Data quality and adequacy represent a challenge in all regions. WHO regions differ with respect to the methods, processes, cut-off values, and weighting used, which limits comparisons of risk assessment results among regions. Ongoing evaluation of indicators within regions and further harmonization of methods between regions are needed to effectively plan risk mitigation activities in a setting of finite resources for funding and continued WPV circulation.

Clinical Infectious Diseases, 2012

Journal of Infectious Diseases, 2014