Measuring protective efficacy and quantifying the impact of drug resistance: A novel malaria chemoprevention trial design and methodology

BACKGROUND

Recently revised WHO guidelines on malaria chemoprevention have opened the door to more tailored implementation. Countries face choices on whether to replace old drugs, target additional age groups, and adapt delivery schedules according to local drug resistance levels and malaria transmission patterns. Regular routine assessment of protective efficacy of chemoprevention is key. Here, we apply a novel modelling approach to aid the design and analysis of chemoprevention trials and generate measures of protection that can be applied across a range of transmission settings.

METHODS AND FINDINGS

We developed a model of genotype-specific drug protection, which accounts for underlying risk of infection and circulating genotypes. Using a Bayesian framework, we fitted the model to multiple simulated scenarios to explore variations in study design, setting, and participant characteristics. We find that a placebo or control group with no drug protection is valuable but not always feasible. An alternative approach is a single-arm trial with an extended follow-up (>42 days), which allows measurement of the underlying infection risk after drug protection wanes, as long as transmission is relatively constant. We show that the currently recommended 28-day follow-up in a single-arm trial results in low precision of estimated 30-day chemoprevention efficacy and low power in determining genotype differences of 12 days in the duration of protection (power = 1.4%). Extending follow-up to 42 days increased precision and power (71.5%) in settings with constant transmission over this time period. However, in settings of unstable transmission, protective efficacy in a single-arm trial was overestimated by 24.3% if recruitment occurred during increasing transmission and underestimated by 15.8% when recruitment occurred during declining transmission. Protective efficacy was estimated with greater precision in high transmission settings, and power to detect differences by resistance genotype was lower in scenarios where the resistant genotype was either rare or too common.

CONCLUSIONS

These findings have important implications for the current guidelines on chemoprevention efficacy studies and will be valuable for informing where these studies should be optimally placed. The results underscore the need for a comparator group in seasonal settings and provide evidence that the extension of follow-up in single-arm trials improves the accuracy of measures of protective efficacy in settings with more stable transmission. Extension of follow-up may pose logistical challenges to trial feasibility and associated costs. However, these studies may not need to be repeated multiple times, as the estimates of drug protection against different genotypes can be applied to different settings by adjusting for transmission intensity and frequency of resistance.

Identification of the PfK13 mutations R561H and P441L in the Democratic Republic of Congo

OBJECTIVES

Partial artemisinin resistance, mediated by Plasmodium falciparum K13 (PfK13) mutations, has been confirmed in certain areas of East Africa that are historically associated with high-level antimalarial resistance. The Democratic Republic of Congo (DRC) borders these areas in the East. This study aimed to determine the prevalence of resistance markers in six National Malaria Control Program surveillance sites; Boende, Kabondo, Kapolowe, Kimpese, Mikalayi, and Rutshuru.

METHODS

The single nucleotide polymorphisms (SNPs) in P. falciparum genes PfK13, Pfdhfr, Pfdhps, Pfmdr1, and Pfcrt were assessed using targeted next-generation sequencing of isolates collected at enrollment in therapeutic efficacy studies.

RESULTS

PfK13 SNPs were detected in two samples: in Kabondo (R561H) and in Rutshuru (P441L), both areas near Uganda and Rwanda. The Pfdhps ISGEGA haplotype, associated with reduced sulfadoxine-pyrimethamine chemoprevention efficacy, ranged from 0.8% in Mikalayi (central DRC) to 42.2% in Rutshuru (East DRC).

CONCLUSIONS

R561H and P441L observed in eastern DRC are a concern, as they are associated with delayed artemisinin-based combination therapies-clearance and candidate marker of resistance, respectively. This is consistent with previous observations of shared drug resistance profiles in parasites of that region with bordering areas of Rwanda and Uganda. The likely circulation of parasites has important implications for the ongoing surveillance of partial artemisinin-resistant P. falciparum and for future efforts to mitigate its dispersal.

Estimating the burden of severe malarial anaemia and access to hospital care in East Africa

Severe malarial anaemia can be fatal if not promptly treated. Hospital studies may under-represent the true burden because cases often occur in settings with poor access to healthcare. We estimate the relationship of community prevalence of malaria infection and severe malarial anaemia with the incidence of severe malarial anaemia cases in hospital, using survey data from 21 countries and hospital data from Kenya, Tanzania and Uganda. The estimated percentage of severe malarial anaemia cases that were hospitalised is low and consistent for Kenya (21% (95% CrI: 7%, 47%)), Tanzania (18% (95% CrI: 5%, 52%)) and Uganda (23% (95% CrI: 9%, 48%)). The majority of severe malarial anaemia cases remain in the community, with the consequent public health burden being contingent upon the severity of these cases. Alongside health system strengthening, research to better understand the spectrum of disease associated with severe malarial anaemia cases in the community is a priority.

Candida pneumonia in young and immunocompetent lady: A case report and literature review

Background

Candida is a frequent respiratory tract colonizer. True candida pneumonia is rare and seen with predominance in immunosuppressed patients. Our aim is to document a previously unreported case of Candida pneumonia in a young and immunocompetent patient, highlighting, an unusual pathological manifestation of this infection in immunocompetent individuals.

Case summary

We report a previously healthy young lady who remained symptomatic with fever, cough and shortness of breath for three weeks duration despite treatment with extensive antibiotics regimen for community acquired pneumonia. She was eventually treated as a probable, rare case of candida pneumonia. The patient demonstrated a dramatic response to single antifungal treatment both clinically and biochemically within the first 24hrs of treatment. Candida albican was isolated on repetitive cultures form the sputum and bronchoalevolar lavage samples. The patient had negative blood cultures. Her HRCT scan revealed bilateral basal air space opacities with peri bronchovascular distribution and centrilobular nodules with branching pattern suggestive of tree in bud predominantly in lower lobes. Her endobronchial biopsies was mostly unremarkable apart from rare non-necrotizing granuloma.

Conclusion

Candida can rarely cause clinically significant pneumonia in immunocompetent patients and should be considered in the differential diagnosis of granulomatous lung disease.

A snapshot of the prevalence of dihydropteroate synthase-431V mutation and other sulfadoxine-pyrimethamine resistance markers in Plasmodium falciparum isolates in Nigeria

BACKGROUND

Malaria is a major public health issue with substantial risks among vulnerable populations. Currently, the World Health Organization (WHO) recommends SP-IPTp in the second and third trimesters. However, the efficacy of SP-IPTp is threatened by the emergence of sulfadoxine-pyrimethamine resistant malaria parasites due to single nucleotide polymorphisms in the Plasmodium falciparum dihydrofolate reductase and dihydropteroate synthetase genes. This study aimed to assess the current prevalence of Pfdhfr/Pfdhps mutations in P. falciparum isolates collected from individuals residing in Ile-Ife, Nigeria, and also present maps of the prevalence of Pfdhps 431V and 581G within Nigeria and surrounding countries.

METHODS

Between October 2020 and April 2021, samples were collected as dried blood spots among 188 participants who showed malaria positivity with a histidine-rich-protein-based rapid diagnostic test (RDT). Nested PCR assays were used to confirm falciparum in the samples with RDT positivity, and to amplify fragments of the Pfdhfr/Pfdhps genes followed by targeted amplicon sequencing. Published data since 2007 on the prevalence of the Pfdhps genotypes in Nigeria and the neighbouring countries were used to produce maps to show the distribution of the mutant genotypes.

RESULTS

Only 74 and 61 samples were successfully amplified for the Pfdhfr and Pfdhps genes, respectively. At codons resulting in N51I, C59R, and S108N, Pfdhfr carried mutant alleles of 97.3% (72/74), 97.3% (72/74) and 98.6% (73/74), respectively. The Pfdhps gene carried mutations at codons resulting in amino acid changes at 431-436-437-540-581-613; I431V [45.9%, (28/61)], A581G [31.1% (19/61)] and A613S [49.2% (30/61)]. Constructed haplotypes were mainly the triple Pfdhfr mutant 51I-59R-108N (95.9%), and the most common haplotypes observed for the Pfdhps gene were the ISGKAA (32.8%), ISGKGS (8.2%), VAGKAA (14.8%), VAGKAS (9.8%) and VAGKGS (14.8%). In the context of the previously published data, a high prevalence of 431V/581G mutations was found in the study population. It seems quite evident that the Pfdhps 431V, 581G and 613S often co-occur as Pfdhps-VAGKGS haplotype.

CONCLUSION

This study showed that the prevalence of VAGKGS haplotype seems to be increasing in prevalence. If this is similar in effect to the emergence of 581G in East Africa, the efficacy of SP-IPTp in the presence of these novel Pfdhps mutants should be re-assessed.

Lung ultrasound to predict gas-exchange response to prone positioning in COVID-19 patients: A prospective study in pilot and confirmation cohorts

PURPOSE

To examine whether lung ultrasound prior to prone positioning can predict the resulting gas-exchange response.

MATERIALS AND METHODS

This is a prospective observational study on critically-ill COVID-19 patients with a pilot and confirmation cohort. Lung ultrasound examinations were performed before prone positioning and gas-exchange parameters were recorded before and after position change.

RESULTS

A total of 79 patients, 36 in the pilot cohort and 43 in the confirmation cohort, were included. In the pilot cohort, a moderate correlation between pre-turn lung ultrasound score index (LUSI) and change in PaO2/FiO2 after prone positioning was found. These findings were corroborated and extended upon in the confirmation cohort. The confirmation cohort found that anterior LUSI had the strongest correlation with follow-up time-points 1, 6, 12, and 24 h after prone positioning, with strength of correlation gradually increasing up to 24 h. In a multivariate model anterior aeration loss (odds ratio 0.035; 95%CI 0.003-0.319 for anterior LUSI >50%) and higher pre-turn PaCO₂ (odds ratio 0.479 95% CI 0.235-0.979) were negatively predictive of a PaO2/FiO2 increase ≥20 mmHg.

CONCLUSIONS

Anterior LUSI, in addition to other clinical parameters, may be used to aid COVID-19 respiratory strategy and a clinician's decision to prone.

Projected health impact of post-discharge malaria chemoprevention among children with severe malarial anaemia in Africa

Children recovering from severe malarial anaemia (SMA) remain at high risk of readmission and death after discharge from hospital. However, a recent trial found that post-discharge malaria chemoprevention (PDMC) with dihydroartemisinin-piperaquine reduces this risk. We developed a mathematical model describing the daily incidence of uncomplicated and severe malaria requiring readmission among 0-5-year old children after hospitalised SMA. We fitted the model to a multicentre clinical PDMC trial using Bayesian methods and modelled the potential impact of PDMC across malaria-endemic African countries. In the 20 highest-burden countries, we estimate that only 2-5 children need to be given PDMC to prevent one hospitalised malaria episode, and less than 100 to prevent one death. If all hospitalised SMA cases access PDMC in moderate-to-high transmission areas, 38,600 (range 16,900-88,400) malaria-associated readmissions could be prevented annually, depending on access to hospital care. We estimate that recurrent SMA post-discharge constitutes 19% of all SMA episodes in moderate-to-high transmission settings.

The Association between Resilience and Psychological Distress during the COVID-19 Pandemic: A Systematic Review and Meta-Analysis

This study examined the association between resilience and psychological distress in healthcare workers, the general population, and patients during the COVID-19 pandemic. We searched the PubMed, Web of Science, PsycInfo, Science Direct, and Nursing and Allied Health databases. Included articles examined healthcare workers (e.g., physicians and nurses), the general population, and patients during the COVID-19 pandemic. Studies of exposure to other infectious diseases related to epidemics or pandemics (e.g., SARS and MERS) were excluded. This study was performed following the Cooper matrix review method and PRISMA guidelines, followed by a meta-analysis of study results using R version 4.1.2. A random effect model was used for the pooled analysis. This study was registered with PROSPERO (registration No. CRD42021261429). Based on the meta-analysis, we found a moderate negative relationship between overall resilience and psychological distress (r = -0.42, 95% confidence interval [CI]: -0.45 to -0.38, p < 0.001). For the subgroup analysis, a moderately significant negative relationship between overall resilience and psychological distress was found among healthcare workers (r = -0.39, 95% CI: -0.44 to -0.33, p < 0.001), which was weaker than in the general population (r = -0.45, 95% CI: -0.50 to -0.39, p < 0.001) and in patients (r = -0.43; 95% CI: -0.52 to -0.33; p < 0.001). This association was robust, although the heterogeneity among individual effect sizes was substantial (I² = 94%, 99%, and 74%, respectively). This study revealed a moderate negative relationship between resilience and psychological distress in healthcare workers, the general population, and patients. For all these populations, interventions and resources are needed to improve individuals' resilience and ability to cope with psychological distress during the COVID-19 pandemic and in future disease outbreaks.

Social contact patterns and implications for infectious disease transmission: a systematic review and meta-analysis of contact surveys

Background:

Transmission of respiratory pathogens such as SARS-CoV-2 depends on patterns of contact and mixing across populations. Understanding this is crucial to predict pathogen spread and the effectiveness of control efforts. Most analyses of contact patterns to date have focused on high-income settings.

Methods:

Here, we conduct a systematic review and individual-participant meta-analysis of surveys carried out in low- and middle-income countries and compare patterns of contact in these settings to surveys previously carried out in high-income countries. Using individual-level data from 28,503 participants and 413,069 contacts across 27 surveys, we explored how contact characteristics (number, location, duration, and whether physical) vary across income settings.

Results:

Contact rates declined with age in high- and upper-middle-income settings, but not in low-income settings, where adults aged 65+ made similar numbers of contacts as younger individuals and mixed with all age groups. Across all settings, increasing household size was a key determinant of contact frequency and characteristics, with low-income settings characterised by the largest, most intergenerational households. A higher proportion of contacts were made at home in low-income settings, and work/school contacts were more frequent in high-income strata. We also observed contrasting effects of gender across income strata on the frequency, duration, and type of contacts individuals made.

Conclusions:

These differences in contact patterns between settings have material consequences for both spread of respiratory pathogens and the effectiveness of different non-pharmaceutical interventions.

Funding:

This work is primarily being funded by joint Centre funding from the UK Medical Research Council and DFID (MR/R015600/1).

Infectious diseases, particularly those caused by airborne pathogens like SARS-CoV-2, spread by social contact, and understanding how people mix is critical in controlling outbreaks. To explore these patterns, researchers typically carry out large contact surveys. Participants are asked for personal information (such as gender, age and occupation), as well as details of recent social contacts, usually those that happened in the last 24 hours. This information includes, the age and gender of the contact, where the interaction happened, how long it lasted, and whether it involved physical touch.

These kinds of surveys help scientists to predict how infectious diseases might spread. But there is a problem: most of the data come from high-income countries, and there is evidence to suggest that social contact patterns differ between places. Therefore, data from these countries might not be useful for predicting how infections spread in lower-income regions.

Here, Mousa et al. have collected and combined data from 27 contact surveys carried out before the COVID-19 pandemic to see how baseline social interactions vary between high- and lower-income settings. The comparison revealed that, in higher-income countries, the number of daily contacts people made decreased with age. But, in lower-income countries, younger and older individuals made similar numbers of contacts and mixed with all age groups.

In higher-income countries, more contacts happened at work or school, while in low-income settings, more interactions happened at home and people were also more likely to live in larger, intergenerational households. Mousa et al. also found that gender affected how long contacts lasted and whether they involved physical contact, both of which are key risk factors for transmitting airborne pathogens.

These findings can help researchers to predict how infectious diseases might spread in different settings. They can also be used to assess how effective non-medical restrictions, like shielding of the elderly and workplace closures, will be at reducing transmissions in different parts of the world.

The Association between GDP and non-communicable disease mortality in the WHO European Region

Background

The WHO Europe Region consists of 53 countries, each of which has differences in mortality from cardiovascular (CVD), neurological, and chronic respiratory diseases. Such diverse metrics result from political, social, and economic events that have influenced the health performance of each European sub-region. From a public health perspective, an updated analysis of such metrics is required for policymakers and health system organisations to improve the overall population health outcomes.

Methods

This study utilised data between 1990-2017 from the Global Burden of Disease study 2017 to explore the association between GDP and NCD mortality in Western, Central, and Eastern Europe and Central Asia. The mortality data was already stratified by age and sex, and a fixed effected regression analysis was run to observe associations between both variables using STATA. Data completeness was 80-100% for GDP and 100% for mortality across the European region. The final results were reported as a rate per 100,000, with confidence intervals. The rate changes were calculated using an equation from the GBD.

Results

The most significant decrease per 100,000 of the population across all three NCDs as GDP increased was in Central Asia and Eastern Europe among both sexes. For every 1000 unit increase in GDP, we expect -12.13 [-13.60, -10.66] and -14.49 [-16.89, -12.29] less deaths in CVD in females and males per 100,000 of population, respectively. Western Europe had the lowest decrease per 100,000 of the population, as with every 1000 unit increase in GDP, we expect -2.42 [-2.59, -2.25] and -4.09 [-4.33, -3.84] fewer deaths in CVD in females and males, respectively.

Conclusions

The overall differential rate of mortality from the three NCDs is decreasing across all regions. However, there is a large disparity between the sexes. Males have a higher mortality rate across CVD and chronic respiratory diseases, whilst neurological disorders were highest among females.

Key messages

This study’s analysis has added to existing knowledge on chronic health patterns in the WHO European region. Governments in Eastern Europe and Central Asia should introduce health policies targeting unhealthy consumption of alcohol, smoking and diets, as seen in Western Europe.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Setting-specific Transmission Rates: A Systematic Review and Meta-analysis

BACKGROUND

Understanding the drivers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission is crucial for control policies, but evidence of transmission rates in different settings remains limited.

METHODS

We conducted a systematic review to estimate secondary attack rates (SARs) and observed reproduction numbers (Robs) in different settings exploring differences by age, symptom status, and duration of exposure. To account for additional study heterogeneity, we employed a beta-binomial model to pool SARs across studies and a negative-binomial model to estimate Robs.

RESULTS

Households showed the highest transmission rates, with a pooled SAR of 21.1% (95% confidence interval [CI]:17.4-24.8). SARs were significantly higher where the duration of household exposure exceeded 5 days compared with exposure of ≤5 days. SARs related to contacts at social events with family and friends were higher than those for low-risk casual contacts (5.9% vs 1.2%). Estimates of SARs and Robs for asymptomatic index cases were approximately one-seventh, and for presymptomatic two-thirds of those for symptomatic index cases. We found some evidence for reduced transmission potential both from and to individuals younger than 20 years of age in the household context, which is more limited when examining all settings.

CONCLUSIONS

Our results suggest that exposure in settings with familiar contacts increases SARS-CoV-2 transmission potential. Additionally, the differences observed in transmissibility by index case symptom status and duration of exposure have important implications for control strategies, such as contact tracing, testing, and rapid isolation of cases. There were limited data to explore transmission patterns in workplaces, schools, and care homes, highlighting the need for further research in such settings.

Children's role in the COVID-19 pandemic: a systematic review of early surveillance data on susceptibility, severity, and transmissibility

SARS-CoV-2 infections have been reported in all age groups including infants, children, and adolescents. However, the role of children in the COVID-19 pandemic is still uncertain. This systematic review of early studies synthesises evidence on the susceptibility of children to SARS-CoV-2 infection, the severity and clinical outcomes in children with SARS-CoV-2 infection, and the transmissibility of SARS-CoV-2 by children in the initial phases of the COVID-19 pandemic. A systematic literature review was conducted in PubMed. Reviewers extracted data from relevant, peer-reviewed studies published up to July 4th 2020 during the first wave of the SARS-CoV-2 outbreak using a standardised form and assessed quality using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. For studies included in the meta-analysis, we used a random effects model to calculate pooled estimates of the proportion of children considered asymptomatic or in a severe or critical state. We identified 2775 potential studies of which 128 studies met our inclusion criteria; data were extracted from 99, which were then quality assessed. Finally, 29 studies were considered for the meta-analysis that included information of symptoms and/or severity, these were further assessed based on patient recruitment. Our pooled estimate of the proportion of test positive children who were asymptomatic was 21.1% (95% CI: 14.0-28.1%), based on 13 included studies, and the proportion of children with severe or critical symptoms was 3.8% (95% CI: 1.5-6.0%), based on 14 included studies. We did not identify any studies designed to assess transmissibility in children and found that susceptibility to infection in children was highly variable across studies. Children's susceptibility to infection and onward transmissibility relative to adults is still unclear and varied widely between studies. However, it is evident that most children experience clinically mild disease or remain asymptomatically infected. More comprehensive contact-tracing studies combined with serosurveys are needed to quantify children's transmissibility relative to adults. With children back in schools, testing regimes and study protocols that will allow us to better understand the role of children in this pandemic are critical.

Social Contact Patterns and Implications for Infectious Disease Transmission: A Systematic Review and Meta-Analysis of Contact Surveys

BACKGROUND

Transmission of respiratory pathogens such as SARS-CoV-2 depends on patterns of contact and mixing across populations. Understanding this is crucial to predict pathogen spread and the effectiveness of control efforts. Most analyses of contact patterns to date have focussed on high-income settings.

METHODS

Here, we conduct a systematic review and individual-participant meta-analysis of surveys carried out in low- and middle-income countries and compare patterns of contact in these settings to surveys previously carried out in high-income countries. Using individual-level data from 28,503 participants and 413,069 contacts across 27 surveys we explored how contact characteristics (number, location, duration and whether physical) vary across income settings.

RESULTS

Contact rates declined with age in high- and upper-middle-income settings, but not in low-income settings, where adults aged 65+ made similar numbers of contacts as younger individuals and mixed with all age-groups. Across all settings, increasing household size was a key determinant of contact frequency and characteristics, but low-income settings were characterised by the largest, most intergenerational households. A higher proportion of contacts were made at home in low-income settings, and work/school contacts were more frequent in high-income strata. We also observed contrasting effects of gender across income-strata on the frequency, duration and type of contacts individuals made.

CONCLUSIONS

These differences in contact patterns between settings have material consequences for both spread of respiratory pathogens, as well as the effectiveness of different non-pharmaceutical interventions.

FUNDING

This work is primarily being funded by joint Centre funding from the UK Medical Research Council and DFID (MR/R015600/1).

Does integrated community case management (iCCM) target health inequities and treatment delays? Evidence from an analysis of Demographic and Health Surveys data from 21 countries in the period 2010 to 2018

Background

Integrated community case management (iCCM) is a programme that can, via community health workers (CHWs), increase access to timely and essential treatments for children. As well as improving treatment coverage, iCCM has an additional equity-focus with the aim of targeting underserved populations. To assess the success of iCCM programmes it is important that we understand the contribution they are making to equitable health coverage.

Methods

We analysed demographic and health survey data from 21 countries over 9 years to assess evidence and evaluate iCCM programmes. We summarise the contribution CHWs are making relative to other health care provider groups and what treatment combinations CHWs are commonly prescribing. We assessed the ability of CHWs to target treatment delays and health inequities by evaluating time to treatment following fever onset and relationships between CHWs and wealth, rurality and remoteness.

Results

There was good evidence that CHWs are being successfully targeted to improve inequities in health care coverage. There is a larger contribution of CHWs in areas with higher poverty, rurality and remoteness. In six surveys CHWs were associated with significantly shorter average time between fever onset and advice or treatment seeking, whilst in one they were associated with significantly longer times. In areas with active CHW programmes, the contribution of CHWs relative to other health care provider groups varied between 11% to 45% of treatment visits. The distribution of types of treatment provided by CHWs was also very variable between countries.

Conclusions

The success of an iCCM programme depends not only on increasing treatment coverage but addressing inequities in access to timely health care. Whilst much work is still needed to attain universal health care targets, and despite incomplete data, there is evidence that iCCM is successfully addressing treatment delays and targeting underserved populations.

The impact of delayed treatment of uncomplicated P. falciparum malaria on progression to severe malaria: A systematic review and a pooled multicentre individual-patient meta-analysis

BACKGROUND

Delay in receiving treatment for uncomplicated malaria (UM) is often reported to increase the risk of developing severe malaria (SM), but access to treatment remains low in most high-burden areas. Understanding the contribution of treatment delay on progression to severe disease is critical to determine how quickly patients need to receive treatment and to quantify the impact of widely implemented treatment interventions, such as 'test-and-treat' policies administered by community health workers (CHWs). We conducted a pooled individual-participant meta-analysis to estimate the association between treatment delay and presenting with SM.

METHODS AND FINDINGS

A search using Ovid MEDLINE and Embase was initially conducted to identify studies on severe Plasmodium falciparum malaria that included information on treatment delay, such as fever duration (inception to 22nd September 2017). Studies identified included 5 case-control and 8 other observational clinical studies of SM and UM cases. Risk of bias was assessed using the Newcastle-Ottawa scale, and all studies were ranked as 'Good', scoring ≥7/10. Individual-patient data (IPD) were pooled from 13 studies of 3,989 (94.1% aged <15 years) SM patients and 5,780 (79.6% aged <15 years) UM cases in Benin, Malaysia, Mozambique, Tanzania, The Gambia, Uganda, Yemen, and Zambia. Definitions of SM were standardised across studies to compare treatment delay in patients with UM and different SM phenotypes using age-adjusted mixed-effects regression. The odds of any SM phenotype were significantly higher in children with longer delays between initial symptoms and arrival at the health facility (odds ratio [OR] = 1.33, 95% CI: 1.07-1.64 for a delay of >24 hours versus ≤24 hours; p = 0.009). Reported illness duration was a strong predictor of presenting with severe malarial anaemia (SMA) in children, with an OR of 2.79 (95% CI:1.92-4.06; p < 0.001) for a delay of 2-3 days and 5.46 (95% CI: 3.49-8.53; p < 0.001) for a delay of >7 days, compared with receiving treatment within 24 hours from symptom onset. We estimate that 42.8% of childhood SMA cases and 48.5% of adult SMA cases in the study areas would have been averted if all individuals were able to access treatment within the first day of symptom onset, if the association is fully causal. In studies specifically recording onset of nonsevere symptoms, long treatment delay was moderately associated with other SM phenotypes (OR [95% CI] >3 to ≤4 days versus ≤24 hours: cerebral malaria [CM] = 2.42 [1.24-4.72], p = 0.01; respiratory distress syndrome [RDS] = 4.09 [1.70-9.82], p = 0.002). In addition to unmeasured confounding, which is commonly present in observational studies, a key limitation is that many severe cases and deaths occur outside healthcare facilities in endemic countries, where the effect of delayed or no treatment is difficult to quantify.

CONCLUSIONS

Our results quantify the relationship between rapid access to treatment and reduced risk of severe disease, which was particularly strong for SMA. There was some evidence to suggest that progression to other severe phenotypes may also be prevented by prompt treatment, though the association was not as strong, which may be explained by potential selection bias, sample size issues, or a difference in underlying pathology. These findings may help assess the impact of interventions that improve access to treatment.

Selection criteria for resuscitation and survivability rates for neonates at the limit of viability

AIM

To evaluate outcomes of a cohort of infants born at 23 weeks' gestational age after introducing a new selection score for resuscitation in the delivery room (DR).

METHODS

This was a retrospective charts review study using data from the maternal and newborn registry funded by the Qatar National Research Fund. Parents were consulted prenatally and their wishes were honored. The plan of resuscitation was based on the new selection score. The seven components of the score were four antenatal and three immediate postnatal in the DR. Each component received a score of zero, one, or two according to its presence, uncertainty or absence, respectively. Only a score of≥7 would receive active resuscitation unless specified otherwise during prenatal consultation.

RESULTS

The study reviewed 60 infants that were delivered over a two year period. The DR death rate was 23 of 60 (38%). Thirty-seven infants (61%) were admitted to the NICU. The score was applied only on 37 infants where all score criteria were reported in their files. Twenty infants had score <7; of them 13 (65%) died in the DR and 7 were admitted to NICU of whom two (29%) survived to discharge. Seventeen babies with scores≥7 admitted to NICU of whom nine (51%) survived to discharge. The survival rate to discharge was 13 of 37(35%). A satisfaction survey included 33 neonatal physicians; 32 neonatologists stated the score was easy to comprehend, 26 voted for easy to implement, and 30 voted for ethical relief and moral comfort.

CONCLUSIONS

Using a resuscitation score of seven was associated with improved survival until the discharge of those infants resuscitated. NICU physicians described the score as functional and convenient.

Vitamin D and cardiometabolic disorders: a review of current evidence, genetic determinants and pathomechanisms

Vitamin D deficiency has been implicated in the pathophysiology of cardiometabolic disorders including obesity, type 2 diabetes mellitus, cardiovascular diseases and polycystic ovary syndrome. Despite a large number of experimental and observational studies supporting a role for vitamin D in these pathologies, randomized controlled trials have reported little to no effect of vitamin D supplementation in the prevention or treatment of these disorders, although some results remain ambiguous. Polymorphisms in genes related to vitamin D metabolism, particularly in the vitamin D receptor and binding protein and the metabolizing enzyme 1-α-hydroxylase, have emerged as potential contributors to these divergent results. It is now becoming increasingly recognized that the effects and potential benefits of vitamin D supplementation may vary by several factors including vitamin D deficiency status, ethnicity and/or the presence of genetic variants, which affect individual responses to supplementation. However, these factors have seldom been explored in the available literature. Future trials should consider inter-individual differences and, in particular, should aim to clarify whether certain subgroups of individuals may benefit from vitamin D supplementation in the context of cardiometabolic health.

Is frailty a stable predictor of mortality across time? Evidence from the Cognitive Function and Ageing Studies

Background

age-specific mortality reduction has been accompanied by a decrease in the prevalence of some diseases and an increase in others. Whether populations are becoming ‘healthier’ depends on which aspect of health is being considered. Frailty has been proposed as an integrative measure to quantify health status.

Objective

to investigate changes in the near-term lethality of frailty before and after a 20-year interval using the frailty index (FI), a summary of age-related health deficit accumulation.

Design

baseline data from the Cognitive Function and Ageing Studies (CFAS) in 1991 (n = 7,635) and 2011 (n = 7,762).

Setting

three geographically distinct UK centres (Newcastle, Cambridgeshire and Nottingham).

Subjects

individuals aged 65 and over (both institutionalised and community-living).

Methods

a 30-item frailty score was used, which includes morbidities, risk factors and subjective measures of disability. Missing items were imputed using multiple imputations by chained equations. Binomial regression was used to investigate the relationship between frailty, age, sex and cohort. Two-year mortality was modelled using logistic regression.

Results

mean frailty was slightly higher in CFAS II (0.19, 95% confidence interval (CI): 0.19–0.20) than CFAS I (0.18, 95% CI: 0.17–0.18). Two-year mortality in CFAS I was higher than in CFAS II (odds ratio (OR) = 1.16, 95% CI: 1.03–1.30). The association between frailty and 2-year mortality was non-linear with an OR of ~1.6 for each 0.10 increment in the FI.

Conclusions

the relationship between frailty and mortality did not significantly differ across the studies. Severe frailty as an indicator of mortality is shown to be a stable construct.

Neoadjuvant chemoradiotherapy followed by radical vulvectomy for adenoid cystic carcinoma of Bartholin's gland: a case report and review of the literature

Adenoid cystic carcinoma (ACC) of Bartholin's gland is a rare variant and around 90 cases have been reported. Herein, the authors re port a locally advanced ACC of Bartholin's gland that was treated with neoadjuvant chemotherapy followed by right radical hemi-vulvectomy and reconstruction with a gracilis musculocutanous flap. There was no evidence of recurrence after three years of follow up.

Vitamin D and cardiometabolic risk factors and diseases

Obesity, type 2 diabetes, and cardiovascular disease (CVD) are the most common preventable causes of morbidity and mortality worldwide. Insulin resistance, which is a shared feature in these conditions, is also strongly linked to the development of polycystic ovary syndrome (PCOS), which is the most common endocrine disease in women of reproductive age and a major cause of infertility. Vitamin D deficiency has reached epidemic proportions worldwide, primarily due to the shift to sedentary, indoor lifestyles and sun avoidance behaviours to protect against skin cancer. In recent years, vitamin D deficiency has been implicated in the aetiology of type 2 diabetes, PCOS and CVD, and has been shown to be associated with their risk factors including obesity, insulin resistance, hypertension, as well as chronic low-grade inflammation. Treating vitamin D deficiency may offer a feasible and cost-effective means of reducing cardiometabolic risk factors at a population level in order to prevent the development of type 2 diabetes and CVD. However, not all intervention studies show that vitamin D supplementation alleviates these risk factors. Importantly, there is significant heterogeneity in existing studies with regards to doses and drug regimens used, populations studied (i.e. vitamin D deficient or sufficient), and the lengths of supplementation, and only few studies have directly examined the effect of vitamin D on insulin secretion and resistance with the use of clamp methods. Therefore, there is a need for well-designed large scale trials to clarify the role of vitamin D supplementation in the prevention of type 2 diabetes, PCOS, and CVD.

The Effect of Silane Treated Hybrid Filler on the Mechanical and Thermal Performance of Carboxylated Nitrile Butadiene Rubber (XNBR) Composites

Carboxylated Nitrile Butadiene Rubber (XNBR) was reinforced with untreated and silane treated hybrid filler. The hybrid filler was composed of organic layered nanosilicates (NLS) and agro polymer based olive husk powder (OHP). The fabricated composites were inspected with regard to their mechanical and thermal properties. It was found that the silane treated hybrid filler was able to improve the tensile strength at break and the tensile modulus as compared to the control. The overall degree of interaction between the matrix and both the untreated and treated hybrid filler was improved. This was evidenced by the increased degree of curing which is the torque difference (τmax–τmin) derived from the moving die rheometer (MDR) and the decreased swelling index data. Dynamic mechanical analysis (DMA) revealed that the apparent was the highest in case of the silane treated hybrid filler. The thermogravimetric analysis (TGA) revealed that the thermal stability of the composites improved with the incorporation of the hybrid filler. The attenuated total reflectance (ATR-IR) revealed that dipole-dipole interactions between the various reactive functional groups namely the carboxylic of the XNBR, the hydroxyl group of the agro-polymer and the silanol of the silane agent occurred during the fabrication stage of the composites. Scanning electron microscopy (SEM) showed that the fracture surface of the samples differ after the incorporation of the treated hybrid filler.

Sociodemographic characteristics associated with blindness in a Nile Delta governorate of Egypt

BACKGROUND

Globally, blindness is associated with old age and being female. Other sociodemographic and socioeconomic status characteristics associated with blindness have included educational attainment, and occupation. These factors reflect exposure to specific risk factors for blinding eye diseases and utilisation of preventive and curative services by specific sectors of the population.

METHODS

A population based survey of blindness and trachoma was conducted in Menofiya governorate in Egypt. 3322 adults 50 years of age and over were sampled from throughout the governorate (population 2.7 million). Visual acuity and clinical conditions were recorded and interviews with respondents were conducted.

RESULTS

Overall, blindness (<6/60 presenting vision in the better eye) was recorded in 13% of the study population. Besides age and sex, other factors associated with blindness (logistic regression) were marital status and poor sanitation in the household.

CONCLUSION

Socioeconomic status does not appear to be a significant factor associated with blindness in adults in this setting. Instead, sociocultural factors, in particular, characteristics associated with gender sensitive decision making within households, are likely to be more important considerations in understanding blindness in these communities. Successfully combating blindness in the Nile Delta of Egypt will require gender sensitive efforts aimed at timely and effective utilisation of eye care services.

Choline deficiency induced by Mycoplasma fermentans enhances apoptosis of rat astrocytes

A choline uptake system accumulating free choline in an energy-dependent process is described in Mycoplasma fermentans. The uptake system has a K(m) of 2.2x10(-5) M and a V(max) of 0.15 nmol 10 min(-1) mg(-1) cell protein and the choline incorporated could be recovered in the soluble fraction as free choline, phosphorylcholine and CDP-choline. Choline accumulation by M. fermentans resulted in a marked choline depletion of the growth medium. The choline depletion of an astrocyte cell culture induced by M. fermentans was associated with the apoptotic death of the cells. Apoptosis was not obtained with heat-inactivated mycoplasmas and could be reversed by the addition of free choline to the growth medium.

RANTES promotes growth and survival of human first-trimester forebrain astrocytes

We have examined the role of alpha and beta chemokines in the promotion of the ontogenetic development of the brain. RANTES was expressed preferentially in human fetal astrocytes in an age-dependent manner. Astrocytes from 5-week-old brains showed high proliferation and reduced survival, whereas 10-week-old astrocytes exhibited opposite effects. These effects were suppressed by anti-RANTES or anti-RANTES receptor antibodies and were enhanced by recombinant RANTES. RANTES induced tyrosine phosphorylation of several cellular proteins and nuclear translocation of STAT-1 in astrocytes. Interferon-gamma (IFN-gamma) was required for RANTES effects because RANTES induced IFN-gamma and only 10-week-old astrocytes expressed the IFN-gamma receptor. Blocking of IFN-gamma with antibody reversed the effects of RANTES, indicating that cytokine/chemokine networks are critically involved in brain development.

Human first trimester forebrain cells express genes for inflammatory and anti-inflammatory cytokines

Using in situ hybridization and immunohistochemistry the induction of potential cytokines [interleukin 1beta (IL-1beta), IL-4, IL-6, IL-10, tumour necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma) and transforming growth factor beta (TGF-beta)] in human embryonic forebrain cells at weeks 5, 7 and 10 of gestation was studied. The aims were to investigate the capacity of these cells to express cytokines, to determine the kinetics of induction and to display the type of cytokine expressing cells in the developing brain. Constitutive cytokine gene expression was recorded from week 5, augmented by about 50% at week 7 and by more than 100% at week 19 (except TGF-beta at week 10). Among other cytokines, IL-1beta exhibited the highest expression at week 10. TGF-beta showed maximum expression at week 7 and declined at week 10. Combined techniques revealed that glial cells are a major source of cytokines. The study show and present for the first time the kinetics of spontaneous cytokine expression in human embryonic forebrain cells. The increased mRNA expressions with age suggest an important role for cytokines in promotion of brain development. The capacity of inducing these cytokines may, however, be implicated in the immunopathogenesis of several brain diseases. The distinctive TGF-beta profile suggests a further role for TGF-beta on modulation of cytokine responses during development.