Assessing the impact of integrated community-based management of severe wasting programs in conflict-stricken south Sudan : a multi-dimensional approach to scalability of nutrition emergency response programs

Community-based management of severe wasting (CMSW) programs have solely focused on exit outcome indicators, often omitting data on nutrition emergency preparedness and scalability. This study aimed to document good practices and generate evidence on the effectiveness and scalability of CMSW programs to guide future nutrition interventions in South Sudan. A total of 69 CMSW program implementation documents and policies were authenticated and retained for analysis, complemented with the analyses of aggregated secondary data obtained over five (2016–2020 for CMSW program performance) to six (wasting prevention) years (2014–2019). Findings suggest a strong and harmonised coordination of CMSW program implementation, facilitated timely and with quality care through an integrated and harmonised multi-agency and multidisciplinary approach. There were challenges to the institutionalisation and ownership of CMSW programs: a weak health system, fragile health budget that relied on external assistance, and limited opportunities for competency-based learning and knowledge transfer. Between 2014 and 2019, the prevalence of wasting fluctuated ac-cording to the agricultural cycle and remained above the emergency threshold of 15% during the July to August lean season. However, during the same period, under-five and crude mortality rates (10,000/day) declined respectively from 1.17 (95% confidence interval (CI): 0.91, 1.43) and 1.00 (95% CI: 0.75, 1.25) to 0.57 (95% CI: 0.38, 0.76) and 0.55 (95% CI: 0.39, 0.70). Both indicators remained below the emergency thresholds, hence suggesting that the emergency response was under control. Over a five-year period (2016–2020), a total of 1,105,546 children (52% girls, 48% boys) were admitted to CMSW programs. The five-year pooled performance indicators (mean [standard deviations]) was 86.4 (18.9%) for recovery, 2.1 (7.8%) for deaths, 5.2 (10.3%) for defaulting, 1.7 (5.7%) for non-recovery, 4.6 (13.5%) for medical transfers, 2.2 (4.7%) for relapse, 3.3 (15.0) g/kg/day for weight gain velocity, and 6.7 (3.7) weeks for the length of stay in the program. In conclusion, all key performance indicators, except the weight gain velocity, met or exceeded the Humanitarian Charter and Minimum Standards in Humanitarian Response. Our findings demonstrate the possibility of implementing robust and resilient CMSAM programs in protracted conflict environments, informed by global guidelines and protocols. They also depict challenges to institutionalisation and ownership

Low and seasonal malaria transmission in the middle Senegal River basin: identification and characteristics of Anopheles vectors

<p>Abstract</p> <p>Background</p> <p>During the last decades two dams were constructed along the Senegal River. These intensified the practice of agriculture along the river valley basin. We conducted a study to assess malaria vector diversity, dynamics and malaria transmission in the area.</p> <p>Methods</p> <p>A cross-sectional entomological study was performed in September 2008 in 20 villages of the middle Senegal River valley to evaluate the variations of <it>Anopheles </it>density according to local environment. A longitudinal study was performed, from October 2008 to January 2010, in 5 selected villages, to study seasonal variations of malaria transmission.</p> <p>Results</p> <p>Among malaria vectors, 72.34% of specimens collected were <it>An. arabiensis</it>, 5.28% <it>An. gambiae </it>of the S molecular form, 3.26% M form, 12.90% <it>An. pharoensis</it>, 4.70% <it>An. ziemanni</it>, 1.48% <it>An. funestus </it>and 0.04% <it>An. wellcomei</it>. <it>Anopheles </it>density varied according to village location. It ranged from 0 to 21.4 <it>Anopheles</it>/room/day and was significantly correlated with the distance to the nearest ditch water but not to the river.</p> <p>Seasonal variations of <it>Anopheles </it>density and variety were observed with higher human biting rates during the rainy season (8.28 and 7.55 <it>Anopheles </it>bite/man/night in October 2008 and 2009 respectively). Transmission was low and limited to the rainy season (0.05 and 0.06 infected bite/man/night in October 2008 and 2009 respectively). During the rainy season, the endophagous rate was lower, the anthropophagic rate higher and L1014F kdr frequency higher.</p> <p>Conclusions</p> <p>Malaria vectors are present at low-moderate density in the middle Senegal River basin with <it>An. arabiensis </it>as the predominant species. Other potential vectors are <it>An. gambiae </it>M and S form and <it>An. funestus</it>. Nonetheless, malaria transmission was extremely low and seasonal.</p

Evaluation of antibody response to Plasmodium falciparum in children according to exposure of Anopheles gambiae s.l or Anopheles funestus vectors

<p>Abstract</p> <p>Background</p> <p>In sub-Saharan areas, malaria transmission was mainly ensured by <it>Anopheles. gambiae </it>s.l. and <it>Anopheles. funestus </it>vectors. The immune response status to <it>Plasmodium falciparum </it>was evaluated in children living in two villages where malaria transmission was ensured by dissimilar species of <it>Anopheles </it>vectors (<it>An. funestus vs An. gambiae </it>s.l.).</p> <p>Methods</p> <p>A multi-disciplinary study was performed in villages located in Northern Senegal. Two villages were selected: Mboula village where transmission is strictly ensured by <it>An. gambiae </it>s.l. and Gankette Balla village which is exposed to several <it>Anopheles </it>species but where <it>An. funestus </it>is the only infected vector found. In each village, a cohort of 150 children aged from one to nine years was followed during one year and IgG response directed to schizont extract was determined by ELISA.</p> <p>Results</p> <p>Similar results of specific IgG responses according to age and <it>P. falciparum </it>infection were observed in both villages. Specific IgG response increased progressively from one-year to 5-year old children and then stayed high in children from five to nine years old. The children with <it>P. falciparum </it>infection had higher specific antibody responses compared to negative infection children, suggesting a strong relationship between production of specific antibodies and malaria transmission, rather than protective immunity. In contrast, higher variation of antibody levels according to malaria transmission periods were found in Mboula compared to Gankette Balla. In Mboula, the peak of malaria transmission was followed by a considerable increase in antibody levels, whereas low and constant anti-malaria IgG response was observed throughout the year in Gankette Balla.</p> <p>Conclusion</p> <p>This study shows that the development of anti-malaria antibody response was profoundly different according to areas where malaria exposure is dependent with different <it>Anopheles </it>species. These results are discussed according to i) the use of immunological tool for the evaluation of malaria transmission and ii) the influence of <it>Anopheles </it>vectors species on the regulation of antibody responses to <it>P. falciparum</it>.</p

B cell diversification Is uncoupled from SAP-mediated selection forces in chronic germinal centers within Peyer's patches

Antibodies secreted within the intestinal tract provide protection from the invasion of microbes into the host tissues. Germinal center (GC) formation in lymph nodes and spleen strictly requires SLAM-associated protein (SAP)-mediated T cell functions; however, it is not known whether this mechanism plays a similar role in mucosal-associated lymphoid tissues. Here, we find that in Peyer's patches (PPs), SAP-mediated T cell help is required for promoting B cell selection in GCs, but not for clonal diversification. PPs of SAP-deficient mice host chronic GCs that are absent in T cell-deficient mice. GC B cells in SAP-deficient mice express AID and Bcl6 and generate plasma cells in proportion to the GC size. Single-cell IgA sequencing analysis reveals that these mice host few diversified clones that were subjected to mild selection forces. These findings demonstrate that T cell-derived help to B cells in PPs includes SAP-dependent and SAP-independent functions