Increasing coverage of pediatric diarrhea treatment in high-burden countries

Background

Diarrhea is the second leading cause of infectious deaths in children under-five globally. Oral rehydration salts (ORS) and zinc could avert an estimated 93% of deaths, but progress to increase coverage of these interventions has been largely stagnant over the past several decades. The Clinton Health Access Initiative (CHAI), along with donors and country governments in India, Kenya, Nigeria, and Uganda, implemented programs to scale-up ORS and zinc coverage from 2012 to 2016. The programs sought to demonstrate that increases in pediatric diarrhea treatment rates are possible at scale in high-burden settings through a holistic approach addressing both supply and demand barriers. We describe the overall program model and the activities undertaken in each country. The overall goal of the paper is to share the program results and lessons learned to inform other countries aiming to scale-up ORS and zinc.

Methods

We used a triangulation approach, using population-based household surveys, public facility audits, and private outlet surveys, to evaluate the program model. We used pre- and post-program population-based household survey data to estimate the changes in coverage of ORS and zinc for treatment of diarrhea cases in children under-five in program areas. We also conducted secondary analysis of Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) surveys in surrounding regions and compared annual coverage changes in the CHAI-supported program geographies to the surrounding regions.

Results

Across CHAI-supported focal geographies, the average ORS coverage across the program areas increased from 35% to 48% and combined ORS and zinc coverage increased from 1% to 24%. ORS coverage increases were statistically significant in the program states in India, from 22% (95% confidence interval CI = 21–23%) to 48% (95% CI = 47–50%) and program states in Nigeria, from 38% (95% CI = 32–40%) to 55% (95% CI = 51–58%). For combined ORS and zinc, coverage increases were statistically significant in all program geographies. Compared to surrounding regions, the estimated annual changes in combined ORS and zinc coverage were greater in program geographies. Using the Lives Saved Tool and based on the coverage changes during the program period, we estimated 76 090 diarrheal deaths were averted in the program geographies.

Conclusions

Increasing ORS and zinc coverage at scale in high-burden countries and states is possible through a comprehensive approach that targets both demand and supply barriers, including pricing, optimal product qualities, provider dispensing practices, stocking rates, and consumer demand.

Vulnerability of Barley to African Pathotypes of Puccinia graminis f. sp. tritici and Sources of Resistance

The emergence of widely virulent pathotypes (e.g., TTKSK in the Ug99 race group) of the stem rust pathogen (Puccinia graminis f. sp. tritici) in Africa threatens wheat production on a global scale. Although intensive research efforts have been advanced to address this threat in wheat, few studies have been conducted on barley, even though pathotypes such as TTKSK are known to attack the crop. The main objectives of this study were to assess the vulnerability of barley to pathotype TTKSK and identify possible sources of resistance. From seedling evaluations of more than 1,924 diverse cultivated barley accessions to pathotype TTKSK, more than 95% (1,844) were found susceptible. A similar high frequency (910 of 934 = 97.4%) of susceptibility was found for the wild progenitor (Hordeum vulgare subsp. spontaneum) of cultivated barley. Additionally, 55 barley lines with characterized or putative introgressions from various wild Hordeum spp. were also tested against pathotype TTKSK but none was found resistant. In total, more than 96% of the 2,913 Hordeum accessions tested were susceptible as seedlings, indicating the extreme vulnerability of the crop to the African pathotypes of P. graminis f. sp. tritici. In total, 32 (1.7% of accessions evaluated) and 13 (1.4%) cultivated and wild barley accessions, respectively, exhibited consistently highly resistant to moderately resistant reactions across all experiments. Molecular assays were conducted on these resistant accessions to determine whether they carried rpg4/Rpg5, the only gene complex known to be highly effective against pathotype TTKSK in barley. Twelve of the 32 (37.5%) resistant cultivated accessions and 11 of the 13 (84.6%) resistant wild barley accessions tested positive for a functional Rpg5 gene, highlighting the narrow genetic base of resistance in Hordeum spp. Other resistant accessions lacking the rpg4/Rpg5 complex were discovered in the evaluated germplasm and may possess useful resistance genes. Combining rpg4/Rpg5 with resistance genes from these other sources should provide more durable resistance against the array of different virulence types in the Ug99 race group.