A Literature Review of the Effect of Malaria on Stunting.

Background: The current version of the Lives Saved Tool (LiST) maternal and child health impact modeling software does not include an effect of malaria on stunting.Objective: This literature review was undertaken to determine whether such a causal link should be included in the LiST model.Methods: The PubMed, Embase, and Scopus databases were searched by using broad search terms. The searches returned a total of 4281 documents. Twelve studies from among the retrieved documents were included in the review according to the inclusion and exclusion criteria.Results: There was mixed evidence for an effect of malaria on stunting among longitudinal observational studies, and none of the randomized controlled trials of malaria interventions found an effect of the interventions on stunting.Conclusions: There is insufficient evidence to include malaria as a determinant of stunting or an effect of malaria interventions on stunting in the LiST model. The paucity and heterogeneity of the available literature were a major limitation. In addition, the studies included in the review consistently fulfilled their ethical responsibility to treat children under observation for malaria, which may have interfered with the natural history of the disease and prevented any observable effect on stunting or linear growth.

Metrics for Identifying Food Security Status and the Population with Potential to Benefit from Nutrition Interventions in the Lives Saved Tool (LiST).

Background: The Lives Saved Tool (LiST) uses the poverty head-count ratio at $1.90/d as a proxy for food security to identify the percentage of the population with the potential to benefit from balanced energy supplementation and complementary feeding (CF) interventions, following the approach used for the Lancet's 2008 series on Maternal and Child Undernutrition. Because much work has been done in the development of food security indicators, a re-evaluation of the use of this indicator was warranted.Objective: The aim was to re-evaluate the use of the poverty head-count ratio at $1.90/d as the food security proxy indicator in LiST.Methods: We carried out a desk review to identify available indicators of food security. We identified 3 indicators and compared them by using scatterplots, Spearman's correlations, and Bland-Altman plot analysis. We generated LiST projections to compare the modeled impact results with the use of the different indicators.Results: There are many food security indicators available, but only 3 additional indicators were identified with the data availability requirements to be used as the food security indicator in LiST. As expected, analyzed food security indicators were significantly positively correlated (P < 0.001), but there was generally poor agreement between them. The disparity between the indicators also increases as the values of the indicators increase. Consequently, the choice of indicator can have a considerable effect on the impact of interventions modeled in LiST, especially in food-insecure contexts.Conclusions: There was no single indicator identified that is ideal for measuring the percentage of the population who is food insecure for LiST. Thus, LiST will use the food security indicators that were used in the meta-analyses that produced the effect estimates. These are the poverty head-count ratio at $1.90/d for CF interventions and the prevalence of a low body mass index in women of reproductive age for balanced energy supplementation interventions.

Available studies fail to provide strong evidence of increased risk of diarrhea mortality due to measles in the period 4-26 weeks after measles rash onset.

BACKGROUND: Measles vaccination effectiveness studies showed dramatic decreases in all-cause mortality in excess of what would be expected from the prevention of measles disease alone. This invited speculation that measles infection may increase the risk of diarrhea morbidity and mortality subsequent to the acute phase of the disease. The aim of the present systematic review is to summarize the existing evidence in the publically available literature pertaining to the putative causal link between measles and diarrhea in the period 4-26 weeks following measles rash onset. METHODS: We searched the PubMed, Embase, Open Grey and Grey Literature Report databases for relevant literature using broad search terms. Prospective, retrospective and case-control studies in low- and middle-income countries involving children under five wherein relevant evidence were presented were included. Data were extracted from the articles and summarized. RESULTS: Fifty abstracts retrieved through the database searches met the initial screening criteria. Twelve additional documents were identified by review of the references of the documents found in the initial searches. Six documents representing five unique studies that presented evidence relevant to the research question were found. Four of the included studies took place in Bangladesh. One of the included studies took place in Sudan. Some measles vaccine effectiveness studies show lower diarrhea morbidity and mortality among the vaccinated. However, children who received vaccine may have differed in important ways from children who did not, such as health service utilization. Additionally, cohort studies following unvaccinated children showed no difference in diarrhea morbidity and mortality between cases and controls more than 4 weeks after measles rash onset. One study showed some evidence that severe measles may predispose children to gastroenteritis, but was not able to show a corresponding increase in the risk of diarrhea mortality. CONCLUSIONS: The available evidence suggests that the risk of measles-associated diarrhea mortality is largely limited to the 5-week period 1 week prior to and 4 weeks after measles rash onset, and that there is no increased risk of diarrhea mortality in the longer-term caused by measles.

Haemophilus influenzae Type b Vaccine Immunogenicity in American Indian/Alaska Native Infants.

OBJECTIVES: American Indian and Alaska Native (AI/AN) infants historically experienced a disproportionate burden of invasive Haemophilus influenzae type b (Hib) disease, especially early in life. PedvaxHIB vaccine is preferentially recommended for AI/AN infants because it elicits protective antibody levels postdose 1. Vaxelis, a hexavalent vaccine that contains the same Hib conjugate as PedvaxHIB but at lower concentration, is recommended for US children, but postdose 1 Hib immunogenicity data are needed to inform whether a preferential recommendation should be made for AI/AN infants. METHODS: We conducted a phase IV randomized, open-label, noninferiority trial comparing postdose 1 immunogenicity of Vaxelis to PedvaxHIB in AI/AN infants. Participants were randomized to receive a primary series of PedvaxHIB or Vaxelis. Serum samples collected 30 days postdose 1 were tested for anti-Hib immunoglobulin G antibody by enzyme-linked immunosorbent assay. The anti-Hib immunoglobulin G geometric mean concentration (GMC) ratio (Vaxelis/PedvaxHIB) was estimated by constrained longitudinal data analysis. Noninferiority was defined a priori as the lower bound of the 95% confidence interval (CI) of the GMC ratio ≥0.67. RESULTS: A total of 327 of the 333 infants enrolled in the study were included in the per-protocol analysis. The postdose 1 anti-Hib GMC was 0.41 µg/mL (95% CI 0.33-0.52) in the Vaxelis group (n = 152) and 0.39 µg/mL (95% CI 0.31-0.50) in the PedvaxHIB group (n = 146). The constrained longitudinal data analysis GMC ratio was 1.03 (95% CI 0.76-1.39). CONCLUSIONS: Postdose 1 immunogenicity of Vaxelis was noninferior to PedvaxHIB. Our findings support the use of Vaxelis in AI/AN children, a population with elevated risk of Hib disease.

Early estimates of the indirect effects of the COVID-19 pandemic on maternal and child mortality in low-income and middle-income countries: a modelling study.

BACKGROUND: While the COVID-19 pandemic will increase mortality due to the virus, it is also likely to increase mortality indirectly. In this study, we estimate the additional maternal and under-5 child deaths resulting from the potential disruption of health systems and decreased access to food. METHODS: We modelled three scenarios in which the coverage of essential maternal and child health interventions is reduced by 9·8-51·9% and the prevalence of wasting is increased by 10-50%. Although our scenarios are hypothetical, we sought to reflect real-world possibilities, given emerging reports of the supply-side and demand-side effects of the pandemic. We used the Lives Saved Tool to estimate the additional maternal and under-5 child deaths under each scenario, in 118 low-income and middle-income countries. We estimated additional deaths for a single month and extrapolated for 3 months, 6 months, and 12 months. FINDINGS: Our least severe scenario (coverage reductions of 9·8-18·5% and wasting increase of 10%) over 6 months would result in 253 500 additional child deaths and 12 200 additional maternal deaths. Our most severe scenario (coverage reductions of 39·3-51·9% and wasting increase of 50%) over 6 months would result in 1 157 000 additional child deaths and 56 700 additional maternal deaths. These additional deaths would represent an increase of 9·8-44·7% in under-5 child deaths per month, and an 8·3-38·6% increase in maternal deaths per month, across the 118 countries. Across our three scenarios, the reduced coverage of four childbirth interventions (parenteral administration of uterotonics, antibiotics, and anticonvulsants, and clean birth environments) would account for approximately 60% of additional maternal deaths. The increase in wasting prevalence would account for 18-23% of additional child deaths and reduced coverage of antibiotics for pneumonia and neonatal sepsis and of oral rehydration solution for diarrhoea would together account for around 41% of additional child deaths. INTERPRETATION: Our estimates are based on tentative assumptions and represent a wide range of outcomes. Nonetheless, they show that, if routine health care is disrupted and access to food is decreased (as a result of unavoidable shocks, health system collapse, or intentional choices made in responding to the pandemic), the increase in child and maternal deaths will be devastating. We hope these numbers add context as policy makers establish guidelines and allocate resources in the days and months to come. FUNDING: Bill & Melinda Gates Foundation, Global Affairs Canada.