Improving access to care and community health in Haiti with optimized community health worker placement

The national deployment of polyvalent community health workers (CHWs) is a constitutive part of the strategy initiated by the Ministry of Health to accelerate efforts towards universal health coverage in Haiti. Its implementation requires the planning of future recruitment and deployment activities for which mathematical modelling tools can provide useful support by exploring optimised placement scenarios based on access to care and population distribution. We combined existing gridded estimates of population and travel times with optimisation methods to derive theoretical CHW geographical placement scenarios including constraints on walking time and the number of people served per CHW. Four national-scale scenarios that align with total numbers of existing CHWs and that ensure that the walking time for each CHW does not exceed a predefined threshold are compared. The first scenario accounts for population distribution in rural and urban areas only, while the other three also incorporate in different ways the proximity of existing health centres. Comparing these scenarios to the current distribution, insufficient number of CHWs is systematically identified in several departments and gaps in access to health care are identified within all departments. These results highlight current suboptimal distribution of CHWs and emphasize the need to consider an optimal (re-)allocation

Improving access to care and community health in Haiti with optimized community health worker placement.

The national deployment of polyvalent community health workers (CHWs) is a constitutive part of the strategy initiated by the Ministry of Health to accelerate efforts towards universal health coverage in Haiti. Its implementation requires the planning of future recruitment and deployment activities for which mathematical modelling tools can provide useful support by exploring optimised placement scenarios based on access to care and population distribution. We combined existing gridded estimates of population and travel times with optimisation methods to derive theoretical CHW geographical placement scenarios including constraints on walking time and the number of people served per CHW. Four national-scale scenarios that align with total numbers of existing CHWs and that ensure that the walking time for each CHW does not exceed a predefined threshold are compared. The first scenario accounts for population distribution in rural and urban areas only, while the other three also incorporate in different ways the proximity of existing health centres. Comparing these scenarios to the current distribution, insufficient number of CHWs is systematically identified in several departments and gaps in access to health care are identified within all departments. These results highlight current suboptimal distribution of CHWs and emphasize the need to consider an optimal (re-)allocation

Suppression of an elicitor-induced oxidative burst reaction in Medicago sativa cell cultures by Sinorhizobium meliloti lipopolysaccharides

Albus U, Baier R, Holst O, Pühler A, Niehaus K. Suppression of an elicitor-induced oxidative burst reaction in Medicago sativa cell cultures by Sinorhizobium meliloti lipopolysaccharides. New Phytologist . 2001;151(3):597-606.The biological activity of lipopolysaccharides (LPS) from the symbiotic soil bacterium Sinorhizobium meliloti was analysed in cell cultures of the host plant Medicago sativa (alfalfa) and the nonhost plant Nicotiana tabacum (tobacco). LPS of S. meliloti were purified and chemically characterized. Alfalfa and tobacco suspension cell cultures responded to yeast elicitors with an alkalinization of the culture medium and the induction of an oxidative burst. This assay was used to study the biological activity of isolated LPS. In alfalfa cell cultures the simultaneous addition of purified LPS of S. meliloti suppressed the elicitor induced alkalinization and oxidative burst reaction. Cell cultures of the nonhost tobacco reacted differently to the application of S. meliloti LIPS. In these cell cultures, the S. meliloti LIPS itself caused an alkalinization of the culture medium and an oxidative burst reaction. S. meliloti LPS released from the bacterial surface might function as a specific signal molecule, promoting the symbiotic interaction and suppressing a pathogenic response in the host plant, alfalfa. (C) New Phytologist (2001)