Self-powered photodetectors: a device engineering perspective

Nanoscale self-powered photodetectors that can work without any external source of energy are required for future applications. There is potential demand for these devices in areas like wireless surveillance, weather forecasting, remote monitoring, and places where the availability of power is scarce. This study provides an overview of state of the art research trends and improvements in self-powered photodetectors. A device engineering perspective for improvement in the figures of merit has been presented along with a description of additional effects like pyro-phototronic, piezo-phototronic, and surface plasmonics.

Strong isolation by distance and evidence of population microstructure reflect ongoing Plasmodium falciparum transmission in Zanzibar

The Zanzibar archipelago of Tanzania has become a low-transmission area for Plasmodium falciparum. Despite being considered an area of pre-elimination for years, achieving elimination has been difficult, likely due to a combination of imported infections from mainland Tanzania, and continued local transmission. To shed light on these sources of transmission, we applied highly multiplexed genotyping utilizing molecular inversion probes to characterize the genetic relatedness of 282 P. falciparum isolates collected across Zanzibar and in Bagamoyo District on the coastal mainland from 2016-2018. Overall, parasite populations on the coastal mainland and Zanzibar archipelago remain highly related. However, parasite isolates from Zanzibar exhibit population microstructure due to rapid decay of parasite relatedness over very short distances. This, along with highly related pairs within shehias, suggests ongoing low level local transmission. We also identified highly related parasites across shehias that reflect human mobility on the main island of Unguja and identified a cluster of highly related parasites, suggestive of an outbreak, in the Micheweni district on Pemba island. Parasites in asymptomatic infections demonstrated higher complexity of infection than those in symptomatic infections, but have similar core genomes. Our data support importation as a main source of genetic diversity and contribution to the parasite population on Zanzibar, but they also show local outbreak clusters where targeted interventions are essential to block local transmission. These results highlight the need for preventive measures against imported malaria and enhanced control measures in areas that remain receptive for malaria reemergence due to susceptible hosts and competent vectors.

Evolution of Spatial Risk of Malaria Infection After a Pragmatic Chemoprevention Program in Response to Severe Flooding in Rural Western Uganda

BACKGROUND

Malaria epidemics result from extreme precipitation and flooding, which are increasing with global climate change. Local adaptation and mitigation strategies will be essential to prevent excess morbidity and mortality.

METHODS

We investigated the spatial risk of malaria infection at multiple timepoints after severe flooding in rural western Uganda employing longitudinal household surveys measuring parasite prevalence and leveraging remotely sensed information to inform spatial models of malaria risk in the 3 months after flooding.

RESULTS

We identified clusters of malaria risk emerging in areas (1) that showed the greatest changes in Normalized Difference Vegetation Index from pre- to postflood and (2) where residents were displaced for longer periods of time and had lower access to long-lasting insecticidal nets, both of which were associated with a positive malaria rapid diagnostic test result. The disproportionate risk persisted despite a concurrent chemoprevention program that achieved high coverage.

CONCLUSIONS

The findings enhance our understanding not only of the spatial evolution of malaria risk after flooding, but also in the context of an effective intervention. The results provide a "proof of concept" for programs aiming to prevent malaria outbreaks after flooding using a combination of interventions. Further study of mitigation strategies-and particularly studies of implementation-is urgently needed.

Provisional Entrants, Exemptions, and Kindergarteners Up-to-Date on Vaccination Before and After a Regulatory Change in Pennsylvania, 2015-2019

OBJECTIVES

Before the 2017-2018 school year, Pennsylvania shortened the grace period for provisional entrants-kindergarteners who are not up-to-date on vaccination and do not have medical or nonmedical exemption-from 8 months to 5 days. We analyzed the impact of this change on school-entry vaccination status.

METHODS

Using data from the Pennsylvania Department of Health for school years 2015-2016 through 2018-2019, we examined state-level trends in Pennsylvania kindergarteners' vaccination status, including the percentage who were up-to-date on each required vaccine, provisionally enrolled, medically exempted from vaccination, and nonmedically exempted from vaccination. Using the Spearman correlation coefficient, we assessed associations at the school level among changes in kindergarteners' vaccination status after the grace period was shortened.

RESULTS

From 2016-2017 to 2017-2018, the provisional entrance rate of kindergarteners in Pennsylvania decreased substantially after the change in the grace period (from 8.1% to 2.2%), the medical exemption rate remained stable, and the nonmedical exemption rate increased slightly (from 1.8% to 2.5%). The percentage of kindergarteners up-to-date on required vaccines increased or remained stable across the study period except for polio, which decreased from 97.9% in 2015-2016 to 96.2% in 2018-2019. The change in provisional entrance rate was negatively associated with change in kindergarteners up-to-date on required vaccines (ρ range, -0.30 to -0.70) but not with change in medical or nonmedical exemptions (ρ range, -0.01 to -0.08).

CONCLUSIONS

Efforts to reduce provisional entrants may increase the percentage of kindergarteners up-to-date on vaccinations at school entry without a corresponding increase in exemptions.

Interaortocaval Lymph Node Metastasis in Gall Bladder Cancer: Is It Regional Node or Metastatic Disease?

BACKGROUND AND OBJECTIVES

Interaortocaval or para-aortic lymph node (IACLN) metastasis in gall bladder cancer (GBC) is usually a contraindication to curative resection with a prognosis similar to liver or peritoneal metastases. However, few authors have reported survival similar to regional lymph node (RLN) positive disease after curative resection in these patients. This study aims to analyse the role of curative surgery in such cases.

METHODS

Data of all patients operated for GBC from 2012 to 2019 was retrieved. Survival of the IACLN- and RLN-positive patients was compared and factors associated with recurrence and survival were analysed.

RESULTS

Patients were divided in RLN-positive (n = 47) and IACLN-positive (n = 17) group. At a median follow-up of 19.7 months, median disease-free survival (18 vs 13 months) and median overall survival (27 vs 20 months) were inferior (p = 0.06) in IACLN group. But it was higher than the patients who received only palliative therapy (median OS, 14 months). Lack of adjuvant therapy was a significant factor for disease recurrence.

CONCLUSION

Selected cases of GBC with IACLN metastases can achieve meaningful survival after curative resection and adjuvant therapy. Survival was inferior to RLN-positive cases but it was higher than the patients who received only palliative chemotherapy. This concept needs further evaluation in a prospective study with larger number of patients.

Practice Patterns and Survival in Patients with Resected Pancreatic Ductal Adenocarcinomas (PDAC) - Results from the Multicentre Indian Pancreatic & Periampullary Adenocarcinoma Project (MIPPAP) Study

BACKGROUND

There is limited data from India with regard to presentation, practice patterns and survivals in resected pancreatic ductal adenocarcinomas (PDACs).

METHODS

The Multicentre Indian Pancreatic & Periampullary Adenocarcinoma Project (MIPPAP) included data from 8 major academic institutions across India and presents the outcomes in upfront resected PDACs from January 2015 to June 2019.

RESULTS

Of 288 patients, R0 resection was achieved in 81% and adjuvant therapy was administered in 75% of patients. With a median follow-up of 42 months (95% CI: 39-45), median DFS for the entire cohort was 39 months (95% CI: 25.4-52.5), and median overall survival (OS) was 45 months (95% CI: 32.3-57.7). A separate analysis was done in which patients were divided into 3 groups: (a) those with stage I and absent PNI (SI&PNI-), (b) those with either stage II/III OR presence of PNI (SII/III/PNI+), and (c) those with stage II/III AND presence of PNI (SII/III&PNI+). The DFS was significantly lesser in patients with SII/III&PNI+ (median 25, 95% CI: 14.1-35.9 months), compared to SII/III/PNI + (median 40, 95% CI: 24-55 months) and SI&PNI- (median, not reached) (p = 0.036)).

CONCLUSIONS

The MIPPAP study shows that resectable PDACs in India have survivals at par with previously published data. Adjuvant therapy was administered in 75% patients. Adjuvant radiotherapy does not seem to add to survival after R0 resection.

Survival and Recurrence Patterns in Patients With Stomach Adenocarcinoma Receiving Chemotherapy or Chemoradiotherapy After D2 Gastrectomy in a Tertiary Care Cancer Institute: A Retrospective Real-World Evidence Cohort Study

Purpose

Clinical trials comparing the efficacy of adjuvant chemotherapy (CT) and chemo radiation therapy (CTRT) for stomach adenocarcinoma have reported equivocal results. Hence, the current retrospective cohort study assessed the long-term survival and recurrence outcomes of these therapies, to generate evidence in a real-world scenario.

Methods and Materials

Pathologically confirmed patients with stomach adenocarcinoma aged ≥18 years who underwent gastrectomy and D2 lymph nodal dissection at a tertiary cancer hospital from January 2010 to October 2017 were enrolled. Hospital-based follow-up was performed until December 2021. Data were gathered from electronic medical records, supplemented by telephonic interviews for patients who could not come for physical follow-up. CT-alone and CTRT cohorts were compared in terms of survival and recurrence outcomes.

Results

The analysis included 158 patients (mean age, 56.42 years; 63.9% male; CT-alone cohort, 69; CTRT cohort, 89). Patients in the CTRT cohort had significantly worse tumor characteristics at baseline (29.2% had the diffuse type of tumor, 94.4% had stage II or III, 68.5% had lympho-vascular space invasion, and 85.4% had lymph node involvement). Recurrence was observed in 13 (19.7%) of the 76 followed-up patients. Although locoregional recurrence was higher in the CT-alone cohort (7 vs 2), distant metastasis was higher in the CTRT cohort (3 vs 1). The overall 5-year survival was 67.0% (SE, 5.0%) and 5-year recurrence-free survival (RFS) was 75.0% (SE, 5.0%). On multivariate Cox regression, no variable was significantly associated with the overall survival, whereas age, positive lymph nodes without extracapsular extension, and lymph node-negative were significantly associated with RFS. The CTRT cohort had significantly (84.0%) higher RFS (hazard ratio, 0.161; 95% CI, 0.056-0.464; P < .001).

Conclusions

Patients who received adjuvant CTRT after D2 dissection showed similar overall survival but significantly higher RFS than the CT-alone cohort, despite having worse baseline tumor characteristics.

Background malaria incidence and parasitemia during the three-dose RTS,S/AS01 vaccination series do not reduce magnitude of antibody response nor efficacy against the first case of malaria

BACKGROUND

RTS,S/AS01 has been recommended by WHO for widespread implementation in medium to high malaria transmission settings. Previous analyses have noted lower vaccine efficacies in higher transmission settings, possibly due to the more rapid development of naturally acquired immunity in the control group.

METHODS

To investigate a reduced immune response to vaccination as a potential mechanism behind lower efficacy in high transmission areas, we examine initial vaccine antibody (anti-CSP IgG) response and vaccine efficacy against the first case of malaria (to exclude the effect of naturally acquired immunity) using data from three study areas (Kintampo, Ghana; Lilongwe, Malawi; Lambaréné, Gabon) from the 2009-2014 phase III trial (NCT00866619). Our key exposures are parasitemia during the vaccination series and background malaria incidence. We calculate vaccine efficacy (one minus hazard ratio) using a cox-proportional hazards model and allowing for the time-varying effect of RTS,S/AS01.

RESULTS

We find that antibody responses to the primary three-dose vaccination series were higher in Ghana than in Malawi and Gabon, but that neither antibody levels nor vaccine efficacy against the first case of malaria varied by background incidence or parasitemia during the primary vaccination series.

CONCLUSIONS

We find that vaccine efficacy is unrelated to infections during vaccination. Contributing to a conflicting literature, our results suggest that vaccine efficacy is also unrelated to infections before vaccination, meaning that control-group immunity is likely a major reason for lower efficacy in high transmission settings, not reduced immune responses to RTS,S/AS01. This may be reassuring for implementation in high transmission settings, though further studies are needed.

Epidemiology of Plasmodium malariae and Plasmodium ovale spp. in Kinshasa Province, Democratic Republic of Congo

Reports suggest non-falciparum species are an underappreciated cause of malaria in sub-Saharan Africa but their epidemiology is ill-defined, particularly in highly malaria-endemic regions. We estimated incidence and prevalence of PCR-confirmed non-falciparum and Plasmodium falciparum malaria infections within a longitudinal study conducted in Kinshasa, Democratic Republic of Congo (DRC) between 2015-2017. Children and adults were sampled at biannual household surveys and routine clinic visits. Among 9,089 samples from 1,565 participants, incidences of P. malariae, P. ovale spp., and P. falciparum infections by 1-year were 7.8% (95% CI: 6.4%-9.1%), 4.8% (95% CI: 3.7%-5.9%) and 57.5% (95% CI: 54.4%-60.5%), respectively. Non-falciparum prevalences were higher in school-age children, rural and peri-urban sites, and P. falciparum co-infections. P. falciparum remains the primary driver of malaria in the DRC, though non-falciparum species also pose an infection risk. As P. falciparum interventions gain traction in high-burden settings, continued surveillance and improved understanding of non-falciparum infections are warranted.

Role of Stereotactic Body Radiation Therapy in Portal Vein Tumor Thrombosis in Hepatocellular Carcinoma: A Prospective Single Institute Experience

PURPOSE/OBJECTIVE(S)

Patients diagnosed with Hepatocellular carcinoma (HCC) complicated with portal vein tumor thrombosis (PVTT) have a limited number of treatment options available and are associated with an overall poor prognosis. With the recent developments in the field of radiation therapy, the role of radiotherapy particularly Stereotactic Body radiotherapy (SBRT) has increased as a loco-regional therapy for HCC. This study was planned to evaluate the role of SBRT in Locally advanced HCC complicated with PVTT and its role as loco-regional therapy.

MATERIALS/METHODS

We conducted a prospective study that included patients diagnosed with HCC complicated with PVTT Child-Turcotte Pugh (CTP) Class A/B with a maximum score of 7, diagnosed on triple phase Contrast-Enhanced - MRI unsuitable for other ablative procedures. Patients with Bilirubin levels > 4 mg/dl, active Hepatitis, CTP score >7, normal liver volume <700cc or history of prior radiotherapy were excluded from the study. Patients underwent a contrast enhanced 4D-CT simulation with abdominal compression and were planned for SBRT using VMAT technique. Patients were followed-up as per Institute protocol. CECT or MRI for a radiological response was done for response assessment using mRECIST criteria version 1.1. A baseline MRI was done at one-month post-SBRT to understand any RT changes in the liver and to differentiate from tumor progression during the response assessment at three months.

RESULTS

A total of 22 patients with HCC were recruited and received SBRT to PVTT, with a dosage between 30-42 Gy over 6 fractions treated on alternate days. Patients were assessed post-treatment with triphasic CE-MRI every 3 months as per institute protocol. Five patients had achieved Complete response in form of Portal vein recanalization. Three patients had Partial response to the treatment. Seven patients maintained stable disease status whereas six patients had disease progression during the entire course of treatment. The response rate (CR+PR) to treatment was 36.3% at the time of analysis. The Overall Response rate (CR+PR+SD) was 69%. No grade 3 or 4 toxicities were observed and treatment was tolerated well by patients. Kaplan-Meier method was applied to calculate the survival probability at various follow-up intervals. The median time for overall survival was 25 months ((95% CI: 15-35). Out of the 22 subjects included in the study, 6 patients died. There was a 78% survival probability at 12 months and a 68% survival probability at 18 months of follow-up.

CONCLUSION

This prospective single-arm study demonstrated the vital role of SBRT in the treatment of Hepatocellular carcinoma with Portal vein tumor thrombosis and its efficacy in terms of achieving excellent local control with relatively lesser toxicities compared with existing treatment modalities. Patients have shown benefit post-treatment in terms of thrombus reduction and restoration of Portal vein flow making them suitable for further treatment like Resection or TACE.

Biological Response Assessment in Hepatocellular Carcinoma Post Stereotactic Body Radiotherapy

PURPOSE/OBJECTIVE(S)

Biological Response in Hepatocellular carcinoma (HCC) is measured in terms of serum alpha-fetoprotein (AFP) which is elevated in nearly 60% HCC patients at baseline and is directly related to the severity of the disease. This biological response is defined as the reduction of more than 50% from the baseline levels and is associated with an increased percentage of tumor necrosis and is directly related to increased loco-regional control. Patients diagnosed with HCC have very limited treatment modalities. With the recent advances in the field of radiation therapy and the development of Stereotactic Body radiotherapy (SBRT), the role of radiotherapy has increased as a loco-regional modality for HCC. In this single-arm prospective study, we evaluated the biological response post-SBRT in patients diagnosed with HCC.

MATERIALS/METHODS

We conducted a prospective study that included patients diagnosed with HCC with baseline elevation of serum AFP, Child-Turcotte Pugh (CTP) Class A/B with a maximum score of 7. Patient's serum AFP levels were recorded at baseline, pre-treatment, and post-treatment. The biological response was measured at 3 months post-treatment and compared with the baseline serum AFP levels using Wilcoxon signed rank test.

RESULTS

A total of 14 patients with HCC were recruited and received SBRT to the target lesion, with a dose between 30-42 Gy over 6 fractions treated on alternate days. Patients were assessed post-treatment at one month with triphasic CEMRI and serum AFP levels. 12 out of 14 patients (85.71%) had a biological response at 3 months follow-up and levels showed further decline unless a progression was found. The median (IQR) serum AFP level was 1131 ng/ml (359-5668 ng/ml) at baseline. Post-treatment serum AFP levels had a median (IQR) value of 156 ng/ml (15-372 ng/ml) showing a near reduction of 86% from baseline, which was significant. 2/14 pts (14.28%) showed no reduction or even increase in serum AFP levels post-treatment.

CONCLUSION

This prospective single-arm study demonstrated the vital role of SBRT in the treatment of HCC and its importance in achieving a better disease control. The response was achieved in 86% of patients with marked reduction of nearly 90% in serum AFP levels as compared to the baseline and increased median OS and PFS as compared to patients not receiving radiotherapy. Further prospective studies are warranted to confirm our findings.

Microsporidia in HIV-Positive and HIV-Negative Pediatric Patients with Diarrhea at a Tertiary Care Hospital

Background  Human microsporidiosis presents as an important and rapidly emerging opportunistic infection. However, the exact burden of this infection especially in the pediatric population of Northern India remains unknown. In this study, we investigated the prevalence of microsporidia among human immunodeficiency virus (HIV)-positive and HIV-negative pediatric patients who presented with diarrhea. Methods  A total of 263 children were recruited consisting of 98 HIV seropositive with diarrhea and 165 HIV seronegative but with diarrhea. Morning stool samples were collected and both direct and formol ether concentrated samples were examined for the presence of intestinal parasites. The modified acid-fast staining was done for coccidian parasites and trichrome stain for microsporidia detection. Further, the species were detected using a real-time polymerase chain reaction (PCR) targeting a conserved region of the small ribosomal subunit rRNA gene of Enterocytozoon bieneusi , Encephalitozoon hellem , Encephalitozoon intestinalis , and Encephalitozoon cuniculi . Results  Overall, one or more parasites were detected in 52.04% (51/98) of HIV seropositive and 53.33% (88/165) of seronegative children ( p  = 0.8391). However, coccidian parasites were detected in a significantly huge number of HIV seropositive children (21.43% [21/98]) as compared with HIV seronegative children (4.24% [7/165]). Microsporidial DNA could be detected in HIV seropositive with diarrhea children (17.35% [17/98]) by PCR. A significant correlation between low CD4 count (≤ 200/μL) and intestinal parasite positivity could be established. Conclusion  Microsporidia is a significant cause of diarrhea in HIV seropositive pediatric patients and should be kept in mind as one of the differential diagnoses in such patients.

Malaria Transmission Intensity and Parasitemia during the Three-Dose RTS,S/AS01 Vaccination Series do not Reduce Magnitude of Antibody Response nor Efficacy Against the First Case of Malaria

Background

RTS,S/AS01 has been recommended by WHO for widespread implementation in medium to high malaria transmission settings. Previous analyses have noted lower vaccine efficacies in higher transmission settings, possibly due to the more rapid development of naturally acquired immunity in the control group.

Methods

To investigate a reduced immune response to vaccination as a potential mechanism behind lower efficacy in high transmission areas, we examine initial vaccine antibody (anti-CSP IgG) response and vaccine efficacy against the first case of malaria to exclude the delayed malaria effect using data from three study areas (Kintampo, Ghana; Lilongwe, Malawi; Lambaréné, Gabon) from the 2009-2014 phase III trial (NCT00866619). Our key exposures are parasitemia during the vaccination series and malaria transmission intensity. We calculate vaccine efficacy (one minus hazard ratio) using a cox-proportional hazards model and allowing for the time-varying effect of RTS,S/AS01.

Results

We find that antibody responses to the primary three-dose vaccination series were higher in Ghana than in Malawi and Gabon, but that neither antibody levels nor vaccine efficacy against the first case of malaria varied by transmission intensity or parasitemia during the primary vaccination series.

Conclusions

We find that vaccine efficacy is unrelated to infections during vaccination. Contributing to a conflicting literature, our results suggest that vaccine efficacy is also unrelated to infections before vaccination, meaning that delayed malaria is likely the main reason for lower efficacy in high transmission settings, not reduced immune responses. This may be reassuring for implementation in high transmission settings, though further studies are needed.

Study of Efficacy and Toxicity of Capecitabine Maintenance After Response to Docetaxel, Cisplatin, and 5-Fluracil-Based Chemotherapy in Advanced Carcinoma Stomach

BACKGROUND

Advanced gastric cancer is associated with poor survival despite chemotherapy. Maintenance chemotherapy has been successfully tried in lung cancer and colorectal cancers however there is scarce literature on maintenance therapy in advanced gastric cancer. We report a prospective non-randomized single-arm trial of capecitabine maintenance after response to docetaxel, cisplatin, and 5-Flurouracil-based chemotherapy.

METHODS

50 patients with advanced gastric cancer, who had achieved response or had stable disease after 6 cycles of Docetaxel, Cisplatin, and 5-Flurouracil (D 75 mg/m2, C 75 mg/m2, FU 750 mg/m2/d d1-d5, q3 weeks) chemotherapy were prospectively selected to receive maintenance chemotherapy with capecitabine (1000mg/ m2 bid d1-d14 q21 days) until progression.

RESULTS

During the median follow-up period of 18 months all patients had progressed, however, there was no treatment-related death, the median time to tumor progression was 10.3 months, with grade 3 and 4 toxicities in 10-15% of patients, and treatment delays in 75% of patients.

CONCLUSIONS

Our study has shown that maintenance chemotherapy with capecitabine post-first-line docetaxel, cisplatin, and 5-FU-based chemotherapy is effective and delays tumor progression. However, toxicity was a concern in our study which led to treatment-related delays but without any treatment-related death. Most patients continued therapy till progression.

Deep tubewell use is associated with increased household microbial contamination in rural Bangladesh: Results from a prospective cohort study among households in rural Bangladesh

Deep tubewells are important sources of arsenic mitigation in rural Bangladesh. Compared to commonly available shallow tubewells, deep tubewells tap into deeper low-arsenic aquifers and greatly reduce exposure to arsenic in drinking-water. However, benefits from these more distant and expensive sources may be compromised by higher levels of microbial contamination at point-of-use (POU). This paper examines differences in microbial contamination levels at source and POU among households using deep tubewells and shallow tubewells, and investigates factors associated with POU microbial contamination among deep tubewell users. We assessed a prospective longitudinal cohort of 500 rural households in Matlab, Bangladesh, across 135 villages. Concentration of Escherichia coli (E. coli) in water samples at source and POU using Compartment Bag Tests (CBTs) was measured across rainy and dry seasons. We employed linear mixed-effect regression models to measure the effect of different factors on log E. coli concentrations among deep tubewell users. CBT results show that log E. coli concentrations are similar at source and at POU during the first dry and rainy season, but are significantly higher at POU among deep tubewell users during the second dry season. Log E. coli at POU among deep tubewell users is positively associated with both presence (exponentiated beta exp(b) = 2.52, 95% Confidence Interval (CI) = 1.70, 3.73) and concentration of E. coli (exp(b) = 1.36, 95% CI = 1.19, 1.54) at source, and walking time to the tubewell source (exp(b) = 1.39, 95% CI = 1.15, 1.69). Drinking-water during the second dry season is associated with reduced log E. coli (exp(b) = 0.33, 95% CI = 0.23, 0.57) compared to the rainy season. These results suggest that while households that use deep tubewells have lower arsenic exposure, they may be at higher risk of consuming microbially contaminated water compared to households that use shallow tubewells.

Epidemiology of Plasmodium malariae and Plasmodium ovale spp. in a highly malaria-endemic country: a longitudinal cohort study in Kinshasa Province, Democratic Republic of Congo

Background

Increasing reports suggest that non-falciparum species are an underappreciated cause of malaria in sub-Saharan Africa, but their epidemiology is not well-defined. This is particularly true in regions of high P. falciparum endemicity such as the Democratic Republic of Congo (DRC), where 12% of the world's malaria cases and 13% of deaths occur.

Methods and Findings

The cumulative incidence and prevalence of P. malariae and P. ovale spp. infection detected by real-time PCR were estimated among children and adults within a longitudinal study conducted in seven rural, peri-urban, and urban sites from 2015-2017 in Kinshasa Province, DRC. Participants were sampled at biannual household survey visits (asymptomatic) and during routine health facility visits (symptomatic). Participant-level characteristics associated with non-falciparum infections were estimated for single- and mixed-species infections. Among 9,089 samples collected from 1,565 participants over a 3-year period, the incidence of P. malariae and P. ovale spp. infection was 11% (95% CI: 9%-12%) and 7% (95% CI: 5%-8%) by one year, respectively, compared to a 67% (95% CI: 64%-70%) one-year cumulative incidence of P. falciparum infection. Incidence continued to rise in the second year of follow-up, reaching 26% and 15% in school-age children (5-14yo) for P. malariae and P. ovale spp., respectively. Prevalence of P. malariae, P. ovale spp., and P. falciparum infections during household visits were 3% (95% CI: 3%-4%), 1% (95% CI: 1%-2%), and 35% (95% CI: 33%-36%), respectively. Non-falciparum malaria was more prevalent in rural and peri-urban vs. urban sites, in school-age children, and among those with P. falciparum co-infection. A crude association was detected between P. malariae and any anemia in the symptomatic clinic population, although this association did not hold when stratified by anemia severity. No crude associations were detected between non-falciparum infection and fever prevalence.

Conclusions

P. falciparum remains the primary driver of malaria morbidity and mortality in the DRC. However, non-falciparum species also pose an infection risk across sites of varying urbanicity and malaria endemicity within Kinshasa, DRC, particularly among children under 15 years of age. As P. falciparum interventions gain traction in high-burden settings like the DRC, continued surveillance and improved understanding of non-falciparum infections are warranted.

An artificial intelligence model that automatically labels roux-en-Y gastric bypasses, a comparison to trained surgeon annotators

INTRODUCTION

Artificial intelligence (AI) can automate certain tasks to improve data collection. Models have been created to annotate the steps of Roux-en-Y Gastric Bypass (RYGB). However, model performance has not been compared with individual surgeon annotator performance. We developed a model that automatically labels RYGB steps and compares its performance to surgeons.

METHODS AND PROCEDURES

545 videos (17 surgeons) of laparoscopic RYGB procedures were collected. An annotation guide (12 steps, 52 tasks) was developed. Steps were annotated by 11 surgeons. Each video was annotated by two surgeons and a third reconciled the differences. A convolutional AI model was trained to identify steps and compared with manual annotation. For modeling, we used 390 videos for training, 95 for validation, and 60 for testing. The performance comparison between AI model versus manual annotation was performed using ANOVA (Analysis of Variance) in a subset of 60 testing videos. We assessed the performance of the model at each step and poor performance was defined (F1-score < 80%).

RESULTS

The convolutional model identified 12 steps in the RYGB architecture. Model performance varied at each step [F1 > 90% for 7, and > 80% for 2]. The reconciled manual annotation data (F1 > 80% for > 5 steps) performed better than trainee's (F1 > 80% for 2-5 steps for 4 annotators, and < 2 steps for 4 annotators). In testing subset, certain steps had low performance, indicating potential ambiguities in surgical landmarks. Additionally, some videos were easier to annotate than others, suggesting variability. After controlling for variability, the AI algorithm was comparable to the manual (p < 0.0001).

CONCLUSION

AI can be used to identify surgical landmarks in RYGB comparable to the manual process. AI was more accurate to recognize some landmarks more accurately than surgeons. This technology has the potential to improve surgical training by assessing the learning curves of surgeons at scale.

A novel design for solar collector used for water heating application having nanofluid as working medium: CFD modeling and simulation

A solar collector is a simple and cheap device that converts solar radiation into valuable heat energy. The thermal performance of the solar collectors can be enhanced significantly with the suspension of nanoparticles in the base fluid. A novel design for a solar-assisted water heater (SWH) is proposed in the current study, and the effect of nanofluid has been investigated on the thermal efficiency of the SWH. The use of nanofluid is one of the prominent methods in comparison to other techniques for improving the performance of solar collectors. Therefore, the base working fluid, i.e., water is mixed with the alumina nanoparticles of average particle size of 30 nm, and they are assumed to be spherical. The flow and thermal characteristics of nanofluid through the solar water heater are simulated numerically with the help of the Eulerian-Eulerian two-phase model using the finite volume method (FVM). The commercial package ANSYS Fluent, is used for modeling the problem under transient conditions with a pressure-based solver. In comparison to a conventional flat plate collector, the proposed solar water heater consists of a corrugated absorber-plate and the effect of the radius of curvature has been investigated on the heat transfer and collector efficiency. With the proposed design, the heat transfer area available with the riser tubes increases remarkably and it leads to a 43% and 14% increase in heat transfer augmentation and collector efficiency, in comparison to the conventional solar water heater.

2353. Distance and Time to Clinic Are Associated with Increased Risk of Detectable HIV-1 Viral Load at a Peripheral Health Center in Rural Western Uganda

Background

Antiretroviral therapy (ART) improves the health of people living with HIV (PLHIV) and reduces HIV transmission. While availability and efficacy of ART have improved in sub-Saharan Africa (SSA), access remains a challenge. Travel burden, measured as travel time, distance, and cost, has been posited as a potential barrier to ART. For example, a previous study at a large, urban referral center in Uganda showed GPS-measured distance was associated with clinic absenteeism. However, others suggest that PLHIV are willing to travel farther for HIV care because of stigma or for higher quality care. Less is known about the effect of travel burden in rural settings where transportation infrastructure is sparse, and there are few transportation options. Therefore, the objective of this study funded by the IDSA GERM Program was to explore potential associations between distance- and time-to-clinic in a highland area of rural western Uganda with HIV outcomes including viral suppression.

Methods

We enrolled 129 adult participants receiving care at the Bugoye ART clinic. Using a handheld GPS device, we mapped routes between participants’ home and clinic recording trip distance, time, and mode of transportation. We abstracted clinical outcomes from participant medical records. Modified Poisson regression with robust error variance was used to estimate risk ratios of associations between main exposures (e.g., distance to clinic, time to clinic) and primary outcomes (e.g., detectable viral load, missed an ART dose, and history of opportunistic infection [OI]).

Results

Distance and time to clinic were significantly and positively associated with probability of detectable viral load. In adjusted analyses, for every 10-km increase in distance, participants were almost twice as likely to have detectable viral loads (PR: 1.95 [95% CI 1.12, 3.41]). For every 10 additional minutes spent traveling, risk of viral non-suppression increased by almost 40% (PR=1.39 [95% CI 1.08, 1.78]). Neither distance nor time to clinic was associated with increased risk having missed an ART dose or history of OI.

Conclusion

These results suggest travel burden may adversely affect achievement of 90/90/90 goals, and novel, decentralized ART distribution mechanisms may be required.

Disclosures

All Authors: No reported disclosures.

Malaria Transmission Intensity Likely Modifies RTS, S/AS01 Efficacy Due to a Rebound Effect in Ghana, Malawi, and Gabon

BACKGROUND

RTS,S/AS01 is the first malaria vaccine to be approved and recommended for widespread implementation by the World Health Organization (WHO). Trials reported lower vaccine efficacies in higher-incidence sites, potentially due to a "rebound" in malaria cases in vaccinated children. When naturally acquired protection in the control group rises and vaccine protection in the vaccinated wanes concurrently, malaria incidence can become greater in the vaccinated than in the control group, resulting in negative vaccine efficacies.

METHODS

Using data from the 2009-2014 phase III trial (NCT00866619) in Lilongwe, Malawi; Kintampo, Ghana; and Lambaréné, Gabon, we evaluate this hypothesis by estimating malaria incidence in each vaccine group over time and in varying transmission settings. After estimating transmission intensities using ecological variables, we fit models with 3-way interactions between vaccination, time, and transmission intensity.

RESULTS

Over time, incidence decreased in the control group and increased in the vaccine group. Three-dose efficacy in the lowest-transmission-intensity group (0.25 cases per person-year [CPPY]) decreased from 88.2% to 15.0% over 4.5 years, compared with 81.6% to -27.7% in the highest-transmission-intensity group (3 CPPY).

CONCLUSIONS

These findings suggest that interventions, including the fourth RTS,S dose, that protect vaccinated individuals during the potential rebound period should be implemented for high-transmission settings.

Serpentine Supra-venous Hyperpigmentation "Badge of Courage" in Fight Against Cancer: An Brief Review

Persistent serpentine supra-venous hyperpigmentation (PSSH) describes a hyperpigmentation of the skin overlying peripheral veins with characteristic of underlying vessels that are patent. It has been described most commonly after injection of chemotherapeutic drugs. We describe a 44 year old man with diagnosed case of Ca stomach on FOLFOX based chemotherapy. After the 1st cycle of Chemotherapy he developed serpentine supra-venous hyperpigmentation. Introduction: Conventional chemotherapy agents commonly cause infusion-site lesions, such as chemical cellulitis due to drug extravasation and evanescent eruptions.(1) 5-Fluorouracil (5-FU) is a cytotoxic agent used mostly in combination to treat a variety of malignant disorders. Hyperpigmentation is a rare side effect occurring with 5-FU infusions; it has been reported in 2-5% of patients. Various types of pigmentary abnormalities have been reported with 5-FU use such as diffuse hyperpigmentation of the face and palms, macular pigmentary changes on the palms and soles, hyperpigmentation overlying the superficial venous network also called serpentine supravenous hyperpigmentation (SSH) and persistent supravenous erythematous eruptions (PSEE).(2) Keywords: Serpentine Supra-venous Hyperpigmentation, Dermatological toxicity, Fluorouracil.

Solar cooking innovations, their appropriateness, and viability

The successful use of solar energy for cooking requires the systems adopted not only to have technical attributes that conveniently address specific cooking requirements but also are socially and economically acceptable to its end-users. When displacing cooking fuels used in developing countries, solar cooking can lead to (i) improved health in children and women, (ii) less local forest degradation, (iii) less local pollution, and (iv) lower contributions to global greenhouse gas emissions. The diverse range of thermal and photovoltaic solar cooking systems available, or under development, in different regions of the world is discussed in the present work. Particular attention is given to the social, cultural, and economic factors that have limited adoption of solar cookers. Technical developments that address these limitations are shown to only be effective when they facilitate traditional ways of cooking particular foods in and at desired times in specific climates.

Breast Cancer in Transgenders: Narrative Review

The molecular pathogenesis of breast cancer (BC), the second most common cancer, varies significantly between sexes, with minimal data in the transgender population. The overall prevalence of BC in transgenders is estimated to be 0.02%. Besides experiencing social disparities, transgenders have to face a lot of discrimination in the healthcare system. Adversities faced, along with the urge to identify with physical attributes to the gender felt by them, forces transgenders to use non-prescribed hormones. Gender affirming hormone therapy (GAHT) is a key feature of transition-related care, rehabbing mental health, and the quality of life of transgenders, but at the expense of their health. Studies have reported that GAHT is associated with severe health conditions such as cancer in transgenders. Estrogens and testosterone are associated with a moderate risk of developing BC. The types of BC diagnosed in transgenders after cross-sex hormone therapy include invasive ductal and neuroendocrine carcinoma, in addition to tubular adenocarcinoma. Although diagnosed at an age earlier compared with ciswomen, BC screening recommendations for transgenders are the same as for ciswomen. This review studies in detail the types of transgenders, their characteristics, different types of breast cancers associated, issues faced while treatment, and their best possible solutions. We also hope to have well-designed research in the future, which will fill the existing gaps in knowledge and provide scientific insight into the transgender population and issues related to their health. There are no international guidelines on screening and management of transgender patients but it appears that breast screening before cosmetic mastectomy, exposure to hormonal therapy for more than 5 years, and as per natal women screening guidelines should be offered to the patient with detailed discussion on the harms and benefits of the same.

Mental Health Impacts of Quarantine: Insights from the COVID-19 International Border Surveillance Study in Toronto, Canada

Introduction

Nations thorughout the world are imposing mandatory quarantine on those entering the country. While such measures may be effective in reducing the importation of COVID-19, the mental health implications remain unclear.

Objectives

This study sought to assess mental well-being and factors associated with changes in mental health in individuals subject to mandatory quarantine following travel.

Methods

Travellers arriving at a large urban international airport completed online questionnaires on arrival and days 7 and 14 of mandated quarantine. Questionnaire items such as travel history, mental health, attitudes towards COVID-19, and protection behaviours were drawn from the World Health Organization Survey Tool for COVID-19.

Results

There was a clinically significant decline in mental health over the course of quarantine among the 10,965 eligible participants. Poor mental health was reported by 5.1% of participants on arrival and 26% on day 7 of quarantine. Factors associated with greater decline in mental health were younger age, female gender, negative views towards quarantine measures, and engaging in fewer COVID-19 prevention behaviours.

Conclusions

While the widespread use of quarantine may be effective in limiting the spread of COVID-19, the mental health implications are profound and have largely been ignored in public policy decision-making. Psychiatry has a role to play in contributing to the public policy debate to ensure that all aspects of health and well-being are reflected in decisions to isolate people from others.

Disclosure

No significant relationships.

Antibiotic Use, Incidence and Risk Factors for Orthopedic Surgical Site Infections in a Teaching Hospital in Madhya Pradesh, India

Orthopedic surgeries contribute to the overall surgical site infection (SSI) events worldwide. In India, SSI rates vary considerably (1.6−38%); however, there is a lack of a national SSI surveillance system. This study aims to identify the SSI incidence, risk factors, antibiotic prescription and susceptibility patterns among operated orthopedic patients in a teaching hospital in India. Data for 1205 patients were collected from 2013 to 2016. SSIs were identified based on the European Centre for Disease Prevention and Control guidelines. The American Society for Anesthesiologists classification system was used to predict patients’ operative risk. Univariable and multivariable backward stepwise logistic regressions were performed. Overall, 7.6% of patients developed SSIs over three years. The most common SSIs causative microorganism was Staphylococcus aureus (7%), whose strains were resistant to penicillin (100%), erythromycin (80%), cotrimoxazole (80%), amikacin (60%) and cefoxitin (60%). Amikacin was the most prescribed antibiotic (36%). Male sex (OR 2.64; 95%CI 1.32−5.30), previous hospitalization (OR 2.15; 95%CI 1.25−3.69), antibiotic prescription during hospitalization before perioperative antibiotic prophylaxis (OR 4.19; 95%CI 2.51−7.00) and postoperative length of stay > 15 days (OR 3.30; 95%CI 1.83−5.95) were identified as significant risk factors. Additionally, preoperative shower significantly increased the SSI risk (OR 4.73; 95%CI 2.72−8.22), which is unconfirmed in the literature so far.

Co-relation of SARS-CoV-2 related 30-d mortality with HRCT score and RT-PCR Ct value-based viral load in patients with solid malignancy

BACKGROUND

Coronavirus disease 2019 (COVID-19) patients with malignancy are published worldwide but are lacking in data from India.

AIM

To characterize COVID-19 related mortality outcomes within 30 d of diagnosis with HRCT score and RT-PCR Ct value-based viral load in various solid malignancies.

METHODS

Patients included in this study were with an active or previous malignancy and with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection from the institute database. We collected data on demographic details, baseline clinical conditions, medications, cancer diagnosis, treatment and the COVID-19 disease course. The primary endpoint was the association between the mortality outcome and the potential prognostic variables, specially, HRCT score, RT-PCR Ct value-based viral load, etc. using logistic regression analyses treatment received in 30 d.

RESULTS

Out of 131 patients, 123 met inclusion criteria for our analysis. The median age was 57 years (interquartile range = 19-82) while 7 (5.7%) were aged 75 years or older. The most prevalent malignancies were of GUT origin 49 (39.8%), hepatopancreatobiliary (HPB) 40 (32.5%). 109 (88.6%) patients were on active anticancer treatment, 115 (93.5%) had active (measurable) cancer. At analysis on May 20, 2021, 26 (21.1%) patients had died. In logistic regression analysis, independent factors associated with an increased 30-d mortality were in patients with the symptomatic presentation. Chemotherapy in the last 4 wk, number of comorbidities (≥ 2 vs none: 3.43, 1.08-8.56). The univariate analysis showed that the risk of death was significantly associated with the HRCT score: for moderate (8-15) [odds ratio (OR): 3.44; 95% confidence interval (CI): 1.3-9.12; P = 0.0132], severe (> 15) (OR: 7.44; 95%CI: 1.58-35.1; P = 0.0112).

CONCLUSION

To the best of our knowledge, this is the first study from India reporting the association of HRCT score and RT-PCR Ct value-based 30-d mortality outcomes in SARS-CoV-2 infected cancer patients.

Clinical Profile and Outcomes of Treatment in Gastric Cancer in Young Patients in India

Introduction Gastric cancer poses an enormous burden across the globe and India in terms of cancer-related mortality. There is paucity of epidemiological and survival data among young gastric cancer patients in India. In this study, we retrospectively analyzed the general characteristics, clinical profile, and survival data of gastric cancer in young patients < 30 years at tertiary care institution at New Delhi, India.

Materials and Methods Young gastric cancer patients (≤30 years) who were registered over a period of 7 years (2010–2017) were analyzed at a tertiary care center. Total of 2,735 patients of gastric cancers were registered out of which 70 cases were younger than 30 years, of which 63 patients were available for final analysis and data was missing for the remaining 7 cases. All patients underwent standard diagnostic and staging investigation and were staged as per American Joint Committee on Cancer 7 staging system. Lymph node ratio was calculated as number of positive nodes by the number of lymph nodes removed and were categorized as ≤0.6 and >0.6. Minimum follow-up of 1 year was required for inclusion in the study. Twelve patients were lost to follow-up and were not included for survival analysis.

Results Younger patients (≤30 years) with gastric cancer were 2.5% of total gastric cancer patients. Mean age was 24.9 years with males being involved twice as commonly as females (2.15:1). Positive family history was present in 14.2% patients and smoking was present in 57.1% patients. Metastatic disease at presentation was present in 69.8% patients, while only 6.4% patients presented with stage I/II disease. Fourteen patients underwent surgery, out of which six patients underwent partial gastrectomy and remaining eight underwent total gastrectomy with D2 nodal dissection. Median overall survival was 10.8 months (8.8–12.8) and 2-year overall survival was 15.1%.

Conclusion Incidence of stomach cancer in young patients is more than expected and more than global average in India. Most of these young patients are presenting in advanced stage and survival is poor compared with typical aged patients

Combined Diagnostic Accuracy of Diffusion and Perfusion MR Imaging to Differentiate Radiation-Induced Necrosis from Recurrence in Glioblastoma

We aimed to use quantitative values derived from perfusion and diffusion-weighted MR imaging (PWI and DWI) to differentiate radiation-induced necrosis (RIN) from tumor recurrence in Glioblastoma (GBM) and investigate the best parameters for improved diagnostic accuracy and clinical decision-making. Methods: A retrospective analysis of follow-up MRI with new enhancing observations was performed in histopathologically confirmed subjects of post-treated GBM, who underwent re-surgical exploration. Quantitative estimation of rCBV (relative cerebral blood volume) from PWI and three methods of apparent diffusion coefficient (ADC) estimation were performed, namely ADC R1 (whole cross-sectional area of tumor), ADC R2 (only solid enhancing lesion), and ADC R3 (central necrosis). ROC curve and logistic regression analysis was completed. A confusion matrix table created using Excel provided the best combination parameters to ameliorate false-positive and false-negative results. Results: Forty-four subjects with a mean age of 46 years (range, 19−70 years) underwent re-surgical exploration with RIN in 28 (67%) and recurrent tumor in 16 (33%) on histopathology. rCBV threshold of >3.4 had the best diagnostic accuracy (AUC = 0.93, 81% sensitivity and 89% specificity). A multiple logistic regression model showed significant contributions from rCBV (p < 0.001) and ADC R3 (p = 0.001). After analysis of confusion matrix ADC R3 > 2032 × 10−6 mm2 achieved 100% specificity with gain in sensitivity (94% vs. 56%). Conclusions: A combination of parameters had better diagnostic performance, and a stepwise combination of rCBV and ADC R3 obviated unnecessary biopsies in 10% (3/28), leading to improved clinical decision-making.

Race, place, and HIV: The legacies of apartheid and racist policy in South Africa

Black South Africans accounted for 6.2 out of 6.4 million people living with HIV in South Africa in 2012, highlighting extreme racial disparities in HIV infection. These racial disparities are the result of structural and historical factors, specifically, the racist policies which were facilitated by segregation before, during, and after Apartheid. First, we describe the theoretical context of how racist policies and segregation are linked to HIV prevalence. Next, using data from a 2012 national survey of South Africans (SABSSM IV) and Statistics South Africa (StatsSA), we describe the race-specific geospatial distribution of HIV in South Africa, provide empirical evidence for the impact of Apartheid on important risk factors for HIV infection, and describe the relationship between these risk factors and HIV within racial groups. Using multilevel logistic regression, we find that segregation increases the odds of HIV infection among Black South Africans, even after adjusting for many covariates which are sometimes blamed, in place of structural factors, for a higher HIV prevalence in Black South Africans. We found that the estimated odds of infection in the most segregated municipality was 1.95 (95% CI: 1.15, 3.32) times the odds of infection in the least segregated municipality for Black South Africans. In addition to segregation, we also find other covariates to be differentially associated with HIV infection depending on race, such as gender, age, and sexual behavior. We also find that the HIV infection odds ratio comparing Black and Coloured (i.e., multiple ethnic groups with mixed ancestries from Africa, Asia, and Europe) South Africans varies over space. These results continue to build evidence for the influence of structural and historical factors on the modern geospatial and demographic distribution of HIV.

Implementation Approaches for Introducing and Overcoming Barriers to Hepatitis B Birth-Dose Vaccine in sub-Saharan Africa

We discuss determinants of hepatitis B birth-dose vaccine uptake in sub-Saharan Africa countries at the policy, facility, and community levels and propose solutions to known barriers of hepatitis B vaccine introduction in low- and middle-income countries.

In sub-Saharan Africa (SSA), chronic viral hepatitis B (HBV) affects more than 60 million people. Mother-to-child transmission is a major contributor to the ongoing HBV epidemic and yet only 11 of 54 (20.3%) SSA countries have introduced the birth dose of HBV vaccine (HepB-BD) into their regular immunization schedule. As more African countries adopt HepB-BD, implementation approaches must be targeted to ensure effective and timely HepB-BD delivery, especially in rural and under-resourced settings. We conducted a systematic literature review of published literature using PubMed. We included 39 articles published from January 2010 to August 2020, as well as gray literature, case studies, and research performed in SSA. We describe barriers to the uptake of HepB-BD in SSA at the policy, facility, and community levels and propose solutions that are relevant to stakeholders wishing to introduce HepB-BD. We highlight the importance and challenge of reaching infants who are born outside of health care facilities (i.e., home deliveries) with HepB-BD in partnership with community health workers. We also discuss the critical role of maternal education and community engagement in future HepB-BD scale-up efforts in SSA.

Environmental surface sampling for SARS-CoV-2 around hospitalized patients with COVID-19 in a tertiary care hospital

Background: The contamination of patients’ surroundings by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains understudied. Discordant findings of SARS-CoV-2 RNA in environmental samples were noted in many reports. Aims and Objectives: The study assessed the extent and persistence of environmental surface contamination in real-world surfaces around COVID-19 patients. Materials and Methods: We sampled the surroundings of two intensive care unit (ICU) and one ward that were occupied by laboratory-confirmed coronavirus disease 2019 (COVID-19) patients. Frequently touched environmental surfaces near patients were swabbed before and after daily environmental disinfection. Results: Of 355 environmental samples, 6 (1.69%) were positive by real-time reverse-transcription polymerase chain reaction assay. Among those, 5 of 75 ICU samples (6.67%) and 1 of 75 ward environmental samples (1.33%) in the pre-fumigation areas occupied by COVID-19 positive patients were positive. No samples obtained within the first 2 h of fumigation and surface disinfection was found to be positive. Conclusion: Surrounding environment of symptomatic COVID-19 patients can get contaminated and in cases of asymptomatic COVID-19 patients, contamination of their surroundings was an uncommon phenomenon. Strict contact barrier precaution, routine cleaning with disinfectants are mandatory hospital infection control practices in the management of patients infected with SARS-CoV-2.

Impact of body mass index on critically ill COVID-19 patients admitted in a tertiary care hospital : a retrospective observational study

Background: Increased body mass index (BMI) is a known risk factor for respiratory infection and is being recognized as a predisposing factor in the COVID‐19 pandemic caused by the severe acute respiratory syndrome coronavirus‐2. Aims and Objectives: This study aimed to assess the association between different body mass index categories with severe COVID-19 patients leading to death. Materials and Methods: This retrospective study of six months included the laboratory-confirmed COVID-19 patients admitted to an ICU of a tertiary care academic health care organization. The medical records were reviewed at least 14 days after admission.  Results: 484 patients were included, and BMI data were available for 306 patients. 40.19% had a normal weight, 26.79% were overweight, 17.97% had BMI 30-34.9 Kg/m2 and 15.03% had BMI ≥ 35 Kg/m2. Overall, 58 patients (18.95%) died within 14 days of ICU admission, 50.98% were discharged alive or referred from the hospital within 14 days, and 30.06% remained hospitalized at 14 days. After controlling for all covariates, there was a significantly increased risk of mortality in the patients with obesity class I (RR 2.03, 95% CI 1.07-3.85, P = 0.030) and patients with obesity class II & III (RR 2.83, 95% CI 1.54–5.22, P <0.001) compared with those with normal BMI. Conclusions: Obesity was associated with an unfavorable outcome among patients with COVID-19. Patients with obesity should be more closely monitored when hospitalized for COVID-19 as there is increasing evidence of relation of severity of COVID-19 and obesity which appears to be a factor in the health risks.

Study of Gemcitabine Plus Nab-Paclitaxel-Based Chemotherapy Regimen as First-Line Treatment in Metastatic Pancreatic Carcinoma

Background  The purpose of this study was to study the effectiveness of gemcitabine and nab-paclitaxel combination as first-line chemotherapy regimen for the treatment of metastatic pancreatic cancer. There is scarcity of data regarding efficacy and toxicity profile of this combination in Indian population.

Aims and Objectives  The primary aim of this study was to assess efficacy of this regimen, for which evaluation done in terms of the objective response rate, progression-free survival (PFS), and overall survival. Safety data were also evaluated.

Materials and Methods  In this prospective study, gemcitabine plus nab-paclitaxel combination chemotherapy was given as first line in metastatic pancreatic carcinoma patients till progression or appearance of grade 3/4 toxicities with treatment.

Results  The study was performed in 30 patients comprising 18 (60%) males and 12 (40%) females. The median age was 60 years. Median number of cycles administered were six cycles per patient. Seventeen patients (56.67%) had a partial response and 0% had complete response. A total of seven (23.3%) patients progressed on chemotherapy and six (20%) had stable disease (SD). The disease control rate (responses and SD) was 76.7%. The median PFS was 5.75 months. There was no statistically significant difference in terms of response rates and baseline CA 19-9 levels. Most common toxicities were hematological toxicities with rates of grade 3/4 anemia and neutropenia of 20%. Among nonhematological toxicities, nausea (46.67%) and fatigue (30%) were the commonest.

Conclusion  Combination of gemcitabine and nab-paclitaxel is active and well tolerated in advanced pancreatic carcinoma. To the best of our knowledge, this is the first such study conducted in India.

Particle composition and morphology over urban environment (New Delhi): Plausible effects on wheat leaves

Particulate matter (PM) deposition on leaves adversely affects physical, chemical and biological nature of agricultural crops resulting in their loss of productivity and yield. Wheat being a staple food in major parts of Northern India and around the World, has been selected for research purpose by designing a study to explore the probable effects of PM deposition on wheat leaves and wheat crops to ensure the food security. PM₅ (Particulate matter with aerodynamic diameter <5 μm) and Dry Deposited Particulate Matter (DDPM) on wheat leaves (Leaf_DDPM) were collected from the wheat crop field in Indian Agriculture Research Institute (IARI), New Delhi for growing and harvesting season of wheat crops (i.e. December 2014 to April 2015). The EDS (Energy Dispersive Spectroscopy) analysis was used for this study and the individual particle analysis revealed the presence of both acidic and alkaline components like C, Al, Si, Fe, Ca, K, S and Mg. The offline characterization tool i.e. SEM (Scanning Electron Microscope) was utilized for obtaining the micrographs which clearly showed the presence of some angular, sharp-edged and spherical particles consisting of both smooth and rough texture. Apart from that, prevalence of slightly non-spherical particles with aspect ratio of range (>1.20-1.40) and CIR (>0.70-0.80) for both PM₅ and leaf_DDPM were observed. The size distribution of individual particles for both PM₅(#194 particles) and Leaf_DDPM(#657 particles) revealed that Surface Equivalent Radius (SER) and Volume Equivalent Radius (VER) of particles observed to be 0.40-0.80 μm while surface area to be 0-1 μm². These particles may easily block stomatal openings (with typical diameter range: 42-51 μm) of wheat leaves and damage internal leaf tissues while particle VER determines the interaction of incoming solar radiation with leaf surfaces. Average PM₅ concentrations ± Standard deviations (μg/m³) were reported to be 231.05 ± 113.03. The XRF (X-Ray Fluorescence) spectrometer analysis of bulk PM₅ revealed the concentrations of non-carbonaceous elements (μg/m³) as N (67.34 ± 16.09), Si (27.44 ± 11.01), Al (7.79 ± 3.37), S (3.88 ± 2.24), Na (2.29 ± 0.94), Mg (1.65 ± 0.62), K (0.51 ± 0.26), Ca (0.60 ± 0.26), Fe (0.54 ± 0.26), Cr (1.10 ± 0.70), Zn (0.05 ± 0.03), P (0.10 ± 0.03), Cu (0.07 ± 0.06). The dominant elemental oxides were calculated as SiO₂, Al₂O₃, SO₄^2-, Na₂O, MgO, K₂O, CaO, Fe₂O₃, Cr₂O₃, ZnO, P₂O₅, Cu₂O with variable concentrations. In high humid conditions, with relative humidity (~85%) during the vegetative and flowering growth stages of wheat crops, presence of C and S rich acidic and hygroscopic particles may cause the corrosion of wheat leaves that ultimately affect the wheat crops.

Dihydroartemisinin-piperaquine chemoprevention and malaria incidence after severe flooding: evaluation of a pragmatic intervention in rural Uganda

BACKGROUND

Malaria epidemics are a well-described phenomenon after extreme precipitation and flooding, which account for nearly half of global disasters over the past two decades. Yet few studies have examined mitigation measures to prevent post-flood malaria epidemics.

METHODS

We conducted an evaluation of a malaria chemoprevention program implemented in response to severe flooding in western Uganda. Children ≤12 years of age from one village were eligible to receive 3 monthly rounds of dihydroartemisinin-piperaquine (DP). Two neighboring villages served as controls. Malaria cases were defined as individuals with a positive rapid diagnostic test result as recorded in health center registers. We performed a difference-in-differences analysis to estimate changes in the incidence and test positivity of malaria between intervention and control villages.

RESULTS

A total of 554 children received at least one round of chemoprevention with 75% participating in at least two rounds. Compared to control villages, we estimated a 53.4% reduction (aRR 0.47, 95% CI 0.34 - 0.62, p<.01) in malaria incidence and a 30% decrease in the test positivity rate (aRR=0.70, CI 0.50 - 0.97, p=0.03) in the intervention village in the six months post-intervention. The impact was greatest among children receiving the intervention, but decreased incidence was also observed in older children and adults (aRR=0.57, CI 0.38-0.84, p<.01).

CONCLUSIONS

Three rounds of chemoprevention with DP delivered under pragmatic conditions reduced the incidence of malaria after severe flooding in western Uganda. These findings provide a proof-of-concept for the use of malaria chemoprevention to reduce excess disease burden associated with severe flooding.

Malaria prevalence and long-lasting insecticidal net use in rural western Uganda: results of a cross-sectional survey conducted in an area of highly variable malaria transmission intensity

Background

Long-lasting insecticidal nets (LLINs) remain a cornerstone of malaria control, but strategies to sustain universal coverage and high rates of use are not well-defined. A more complete understanding of context-specific factors, including transmission intensity and access to health facilities, may inform sub-district distribution approaches and tailored messaging campaigns.

Methods

A cross-sectional survey of 2190 households was conducted in a single sub-county of western Uganda that experiences highly variable malaria transmission intensity. The survey was carried out approximately 3 years after the most recent mass distribution campaign. At each household, study staff documented reported LLIN use and source among children 2 to 10 years of age and performed a malaria rapid diagnostic test. Elevation and distance to the nearest health facility was estimated for each household. Associations between parasite prevalence and LLIN use were estimated from log binomial regression models with elevation and distance to clinic being the primary variables of interest.

Results

Overall, 6.8% (148 of 2170) of children age 2–10 years of age had a positive RDT result, yielding a weighted estimate of 5.8% (95% confidence interval [CI] 5.4–6.2%). There was substantial variability in the positivity rates among villages, with the highest elevation villages having lower prevalence than lowest-elevation villages (p < .001). Only 64.7% (95% CI 64.0–65.5%) of children were reported to have slept under a LLIN the previous night. Compared to those living < 1 km from a health centre, households at ≥ 2 km were less likely to report the child sleeping under a LLIN (RR 0.86, 95% CI 0.83–0.89, p < .001). Households located farther from a health centre received a higher proportion of LLINs from government distributions compared to households living closer to health centres.

Conclusions

LLIN use and sourcing was correlated with household elevation and estimated distance to the nearest health facility. The findings suggest that current facility-based distribution strategies are limited in their reach. More frequent mass distribution campaigns and complementary approaches are likely required to maintain universal LLIN coverage and high rates of use among children in rural Uganda.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03835-7.

Individual, household and neighborhood risk factors for malaria in the Democratic Republic of the Congo support new approaches to programmatic intervention

BACKGROUND

The Democratic Republic of the Congo (DRC) remains one of the countries most impacted by malaria despite decades of control efforts, including multiple mass insecticide treated net (ITN) distribution campaigns. The multi-scalar and complex nature of malaria necessitates an understanding of malaria risk factors over time and at multiple levels (e.g., individual, household, community). Surveillance of households in both rural and urban settings over time, coupled with detailed behavioral and geographic data, enables the detection of seasonal trends in malaria prevalence and malaria-associated behaviors as well as the assessment of how the local environments within and surrounding an individual's household impact malaria outcomes.

METHODS

Participants from seven sites in Kinshasa Province, DRC were followed for over two years. Demographic, behavioral, and spatial information was gathered from enrolled households. Malaria was assessed using both rapid diagnostic tests (RDT) and polymerase chain reaction (PCR) and seasonal trends were assessed. Hierarchical regression modeling tested associations between behavioral and environmental factors and positive RDT and PCR outcomes at individual, household and neighborhood scales.

RESULTS

Among 1591 enrolled participants, malaria prevalence did not consistently vary seasonally across the sites but did vary by age and ITN usage. Malaria was highest and ITN usage lowest in children ages 6-15 years across study visits and seasons. Having another member of the household test positive for malaria significantly increased the risk of an individual having malaria [RDT: OR = 4.158 (2.86-6.05); PCR: OR = 3.37 (2.41-4.71)], as did higher malaria prevalence in the 250 m neighborhood around the household [RDT: OR = 2.711 (1.42-5.17); PCR: OR = 4.056 (2.3-7.16)]. Presence of water within close proximity to the household was also associated with malaria outcomes.

CONCLUSIONS

Taken together, these findings suggest that targeting non-traditional age groups, children >5 years old and teenagers, and deploying household- and neighborhood-focused interventions may be effective strategies for improving malaria outcomes in high-burden countries like the DRC.

Effectiveness of a national mass distribution campaign of long-lasting insecticide-treated nets and indoor residual spraying on clinical malaria in Malawi, 2018-2020

Introduction

Malawi’s malaria burden is primarily assessed via cross-sectional national household surveys. However, malaria is spatially and temporally heterogenous and no analyses have been performed at a subdistrict level throughout the course of a year. The WHO recommends mass distribution of long-lasting insecticide-treated bed nets (LLINs) every 3 years, but a national longitudinal evaluation has never been conducted in Malawi to determine LLIN effectiveness lifespans.

Methods

Using District Health Information Software 2 (DHIS2) health facility data, available from January 2018 to June 2020, we assessed malaria risk before and after a mass distribution campaign, stratifying by age group and comparing risk differences (RDs) by LLIN type or annual application of indoor residual spraying (IRS).

Results

711 health facilities contributed 20 962 facility reports over 30 months. After national distribution of 10.7 million LLINs and IRS in limited settings, malaria risk decreased from 25.6 to 16.7 cases per 100 people from 2018 to 2019 high transmission seasons, and rebounded to 23.2 in 2020, resulting in significant RDs of −8.9 in 2019 and −2.4 in 2020 as compared with 2018. Piperonyl butoxide (PBO)-treated LLINs were more effective than pyrethroid-treated LLINs, with adjusted RDs of −2.3 (95% CI −2.7 to −1.9) and −1.5 (95% CI −2.0 to −1.0) comparing 2019 and 2020 high transmission seasons to 2018. Use of IRS sustained protection with adjusted RDs of −1.4 (95% CI −2.0 to −0.9) and −2.8% (95% CI −3.5 to −2.2) relative to pyrethroid-treated LLINs. Overall, 12 of 28 districts (42.9%) experienced increases in malaria risk in from 2018 to 2020.

Conclusion

LLINs in Malawi have a limited effectiveness lifespan and IRS and PBO-treated LLINs perform better than pyrethroid-treated LLINs, perhaps due to net repurposing and insecticide-resistance. DHIS2 provides a compelling framework in which to examine localised malaria trends and evaluate ongoing interventions.

The Nonclinical Disposition and PK/PD Properties of GalNAc-conjugated siRNA Are Highly Predictable and Build Confidence in Translation to Man

Conjugation of oligonucleotide therapeutics, including small interfering ribonucleic acids (siRNAs) or antisense oligonucleotides (ASOs) to N-acetylgalactosamine (GalNAc) ligands has become the primary strategy for hepatocyte-targeted delivery, and with the recent approvals of GIVLAARI® (givosiran) for the treatment of acute hepatic porphyria, OXLUMO^TM (lumasiran) for the treatment of primary hyperoxaluria, and Leqvio® (inclisiran) for the treatment of hypercholesterolemia, the technology has been well-validated clinically. While much knowledge has been gained over decades of development there is a paucity of published literature on the DMPK properties of GalNAc-siRNA. With this in mind the goals of this mini-review are to provide an aggregate analysis of these nonclinical ADME data to build confidence on the translation of these properties to human. Upon subcutaneous administration, GalNAc-conjugated siRNAs are quickly distributed to the liver, resulting in plasma pharmacokinetic (PK) properties that reflect rapid elimination through ASGPR-mediated uptake from circulation into hepatocytes. These studies confirm that liver PK, including half-life and, most importantly, siRNA levels in RNA-induced silencing complex (RISC) in hepatocytes are better predictors of pharmacodynamics (PD) than plasma PK. Several in vitro and in vivo nonclinical studies were conducted to characterize the absorption, distribution, metabolism and excretion (ADME) properties of GalNAc-conjugated siRNAs. These studies demonstrate that the PK/PD and ADME properties of GalNAc-conjugated siRNAs are highly conserved across species, largely predictable, and can be accurately scaled to human, allowing us to identify efficacious and safe clinical dosing regimens in the absence of human liver PK profiles. Significance Statement Several nonclinical ADME studies have been conducted in order to provide a comprehensive overview of the disposition and elimination of GalNAc-conjugated siRNAs and the PK/PD translation between species. These studies demonstrate that the ADME properties of GalNAc-conjugated siRNAs are well correlated and predictable across species building confidence in the ability to extrapolate to human.

Role of Maintenance Gemcitabine in Advanced Carcinoma Gallbladder

Objective  The aim of this study is to investigate the effects of gemcitabine maintenance on progression-free survival (PFS) in patients with metastatic gallbladder cancer (GBC).

Materials and Methods  Sixty patients with unresectable or metastatic GBC having ongoing response to treatment with initial six cycles of gemcitabine and a platinum-based doublet chemotherapy were prospectively randomized on day 21 of the 6th cycle in 1:1 fashion to receive either maintenance gemcitabine 1 g/m ² intravenously on day 1 and day 8 of three weekly cycle or observation. Survival analysis was performed using the Kaplan–Meier method and comparisons by the log-rank test. A p -value < 0.05 was considered as statistically significant.

Results  Of 60 patients, a total of 56 were available for final analysis. The median PFS was 4.7 months (3.1–6.3) in gemcitabine arm and 2.6 months (2.4–2.8) in observation arm, hazard ratio (HR) 0.196 (95% confidence interval [CI]: 0.1–0.39), p < 0.001. Median overall survival in gemcitabine arm was 12.4 months (9.15–15.6) as opposed to 9.9 months (8.29–11.5) in observation arm, HR 0.76 (95% CI: 0.43–1.35), p = 0.354. The grade 3 or 4 side effects in maintenance arm were transaminitis (17.9%), thrombocytopenia (17.8%), neutropenia (14.2%), and febrile neutropenia (7.1%).

Conclusions  Maintenance gemcitabine therapy in unresectable/metastatic GBC patients responding to first-line gemcitabine and platinum treatment contributes to increase PFS with minimal and manageable side effects.

The Burden of Malaria in the Democratic Republic of the Congo

Despite evidence that older children and adolescents bear the highest burden of malaria, large malaria surveys focus on younger children. We used polymerase chain reaction data from the 2013-2014 Demographic and Health Survey in the Democratic Republic of Congo (including children aged <5 years and adults aged ≥15 years) and a longitudinal study in Kinshasa Province (participants aged 6 months to 98 years) to estimate malaria prevalence across age strata. We fit linear models and estimated prevalences for each age category; adolescents aged 10-14 years had the highest prevalence. We estimate approximately 26 million polymerase chain reaction-detectable infections nationally. Adolescents and older children should be included in surveillance studies.

Current Treatment Approaches for Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer in Adjuvant and Neoadjuvant Settings

Breast cancer (BC) is the second most common cancer and the second leading cause of mortality among women globally. Approximately 20 to 25% of BC patients have amplification of the human epidermal growth factor receptor 2 (HER2) genes, a marker of poor prognosis. However, the introduction of anti-HER2-therapies (trastuzumab, followed closely by lapatinib, pertuzumab, trastuzumab emtansine, and neratinib) has changed the natural history of HER2-positive BC and improved the outcome in HER2-positive BC patients. The preeminence of anti-HER2 combination therapy in achieving complete inhibition of the various HER receptor dimers has been demonstrated in clinical studies. However, despite these therapeutic advances, tumors expressing estrogen receptor have poorer responses to targeted therapy and are more likely to relapse. A better understanding of resistance to existing anti-HER2 agents, along with the role played by the microenvironment and of interconnected signaling pathways, can permit tailor-made therapeutic options for each patient. This review aimed to evaluate treatment approaches for BC patients with HER2-positive disease in the adjuvant and neoadjuvant settings, also exploring the possibilities of extended duration of anti-HER2 maintenance therapy.