Canopy temperatures strongly overestimate leaf thermal safety margins of tropical trees.

Current estimates of temperature effects on plants mostly rely on air temperature, although it can significantly deviate from leaf temperature (Tleaf). To address this, some studies have used canopy temperature (Tcan). However, Tcan fails to capture the fine-scale variation in Tleaf among leaves and species in diverse canopies. We used infrared radiometers to study Tleaf and Tcan and how they deviate from air temperature (ΔTleaf and ΔTcan) in multispecies tropical tree plantations at three sites along an elevation and temperature gradient in Rwanda. Our results showed high Tleaf (up to c. 50°C) and ΔTleaf (on average 8-10°C and up to c. 20°C) of sun-exposed leaves during 10:00 h-15:00 h, being close to or exceeding photosynthetic heat tolerance thresholds. These values greatly exceeded simultaneously measured values of Tcan and ΔTcan, respectively, leading to strongly overestimated leaf thermal safety margins if basing those on Tcan data. Stomatal conductance and leaf size affected Tleaf and Tcan in line with their expected influences on leaf energy balance. Our findings highlight the importance of leaf traits for leaf thermoregulation and show that monitoring Tcan is not enough to capture the peak temperatures and heat stress experienced by individual leaves of different species in tropical forest canopies.

Plasticity and implications of water-use traits in contrasting tropical tree species under climate change.

Plants face a trade-off between hydraulic safety and growth, leading to a range of water-use strategies in different species. However, little is known about such strategies in tropical trees and whether different water-use traits can acclimate to warming. We studied five water-use traits in 20 tropical tree species grown at three different altitudes in Rwanda (RwandaTREE): stomatal conductance (gs), leaf minimum conductance (gmin), plant hydraulic conductance (Kplant), leaf osmotic potential (ψo) and net defoliation during drought. We also explored the links between these traits and growth and mortality data. Late successional (LS) species had low Kplant, gs and gmin and, thus, low water loss, while low ψo helped improve leaf water status during drought. Early successional (ES) species, on the contrary, used more water during both moist and dry conditions and exhibited pronounced drought defoliation. The ES strategy was associated with lower mortality and more pronounced growth enhancement at the warmer sites compared to LS species. While Kplant and gmin showed downward acclimation in warmer climates, ψo did not acclimate and gs measured at prevailing temperature did not change. Due to distinctly different water use strategies between successional groups, ES species may be better equipped for a warmer climate as long as defoliation can bridge drought periods.

Handling the heat - photosynthetic thermal stress in tropical trees.

Warming climate increases the risk for harmful leaf temperatures in terrestrial plants, causing heat stress and loss of productivity. The heat sensitivity may be particularly high in equatorial tropical tree species adapted to a thermally stable climate. Thermal thresholds of the photosynthetic system of sun-exposed leaves were investigated in three tropical montane tree species native to Rwanda with different growth and water use strategies (Harungana montana, Syzygium guineense and Entandrophragma exselsum). Measurements of chlorophyll fluorescence, leaf gas exchange, morphology, chemistry and temperature were made at three common gardens along an elevation/temperature gradient. Heat tolerance acclimated to maximum leaf temperature (Tleaf ) across the species. At the warmest sites, the thermal threshold for normal function of photosystem II was exceeded in the species with the highest Tleaf despite their higher heat tolerance. This was not the case in the species with the highest transpiration rates and lowest Tleaf . The results point to two differently effective strategies for managing thermal stress: tolerance through physiological adjustment of leaf osmolality and thylakoid membrane lipid composition, or avoidance through morphological adaptation and transpiratory cooling. More severe photosynthetic heat stress in low-transpiring montane climax species may result in a competitive disadvantage compared to high-transpiring pioneer species with more efficient leaf cooling.

Development of a simple and effective online training for health workers: results from a pilot in Nigeria.

BACKGROUND: Health workers (HWs) in Africa face challenges accessing and learning from existing online training opportunities. To address these challenges, we developed a modular, self-paced, mobile-ready and work-relevant online course covering foundational infection prevention and control (IPC) concepts. Here, we evaluate the first pilot of this course, conducted with HWs in Nigeria. METHODS: We used a learner-centered design and prototyping process to create a new approach to delivering online training for HWs. The resulting course comprised 10 self-paced modules optimized for use on mobile devices. Modules presented IPC vignettes in which learning was driven by short assessment questions with feedback. Learners were recruited by distributing a link to the training through Nigeria-based email lists, WhatsApp groups and similar networks of HWs, managers and allied professionals. The course was open to learners for 8 weeks. We tracked question responses and time on task with platform analytics and assessed learning gains with pre- and post-testing. Significance was evaluated with the Wilcoxon signed-rank test, and effect size was calculated using Cohen's d. RESULTS: Three hundred seventy-two learners, with roles across the health system, enrolled in the training; 59% completed all 10 modules and earned a certificate. Baseline knowledge of foundational IPC concepts was low, as measured by pre-test scores (29%). Post-test scores were significantly higher at 54% (effect size 1.22, 95% confidence interval 1.00-1.44). Learning gains were significant both among learners with low pre-test scores and among those who scored higher on the pre-test. We used the Net Promoter Score (NPS), a common user experience metric, to evaluate the training. The NPS was + 62, which is slightly higher than published scores of other self-paced online learning experiences. CONCLUSIONS: High completion rates, significant learning gains and positive feedback indicate that self-paced, mobile-ready training that emphasizes short, low-stakes assessment questions can be an effective, scalable way to train HWs who choose to enroll. Low pre-test scores suggest that there are gaps in IPC knowledge among this learner population.

Results of the Kigali Imbereheza Project: A 2-Arm Individually Randomized Trial of TI-CBT Enhanced to Address ART Adherence and Mental Health for Rwandan Youth Living With HIV.

BACKGROUND: Adolescents living with HIV have elevated mental distress and suboptimal antiretroviral therapy (ART) adherence. SETTING: Two urban clinics in Kigali, Rwanda. METHODS: A 2-arm individual randomized controlled trial compared Trauma-Informed Cognitive Behavioral Therapy enhanced to address HIV (TI-CBTe) with usual care (time-matched, long-standing, unstructured support groups) with 356 12- to 21-year-old (M = 16.78) Rwandans living with HIV. TI-CBTe included 6 group-based 2-hour sessions led by trained and supervised 21- to 25-year-old Rwandans living with HIV. Participants reported their ART adherence, depression/anxiety, and Post-Traumatic Stress Disorder symptoms at baseline, 6, 12, and 18 months. RESULTS: ART adherence was relatively high at baseline, and youth reported elevated rates of depression/anxiety and trauma symptoms. There were no differential treatment effects on adherence, but depression/anxiety improved over time. Youth with lower depression/anxiety at baseline seemed to benefit more from TI-CBTe than usual care, whereas women with high baseline distress seemed to benefit more from usual care. Youth were less likely to score in high Post-Traumatic Stress Disorder symptom categories at the follow-up, with no differential treatment effects. CONCLUSIONS: TI-CBTe did not outperform usual care on ART adherence, possibly reflecting relatively high adherence at baseline, simplified medication regimens over time, a strong comparison condition, or because youth assigned to TI-CBTe returned to their support groups after the intervention. TI-CBTe was more effective for youth with lower depression/anxiety symptoms, whereas youth with high distress benefitted more from the support groups. TI-CBTe was feasible and acceptable, and young adults living with HIV were able to deliver a mental health intervention with fidelity. The powerful nature of the comparison group, ongoing support groups, points to the potential value of locally crafted interventions in low-resource settings.

Drought stress recovery of hydraulic and photochemical processes in Neotropical tree saplings.

Climate models predict an increase in the severity and the frequency of droughts. Tropical forests are among the ecosystems that could be highly impacted by these droughts. Here, we explore how hydraulic and photochemical processes respond to drought stress and re-watering. We conducted a pot experiment on saplings of five tree species. Before the onset of drought, we measured a set of hydraulic traits, including minimum leaf conductance, leaf embolism resistance and turgor loss point. During drought stress, we monitored traits linked to leaf hydraulic functioning (leaf water potential (ψmd) and stomatal conductance (gs)) and traits linked to leaf photochemical functioning (maximum quantum yield of photosystem II (Fv/Fm) and maximum electron transport rate (ETRmax)) at different wilting stages. After re-watering, the same traits were measured after 3, 7 and 14 days. Hydraulic trait values decreased faster than photochemical trait values. After re-watering, the values of the four traits recovered at different rates. Fv/Fm recovered very fast close to their initial values only 3 days after re-watering. This was followed by ETRmax, Ψmd and gs. Finally, we show that species with large stomatal and leaf safety margin and low πtlp are not strongly impacted by drought, whereas they have a low recovery on photochemical efficiency. These results demonstrate that πtlp, stomatal and leaf safety margin are a good indicators of plant responses to drought stress and also to recovery for photochemical efficiency.

Improving hand hygiene measures in low-resourced intensive care units: experience at the Kigali University Teaching Hospital in Rwanda.

Background: Proper hand hygiene (HH) practices have been shown to reduce healthcare-acquired infections. Several potential challenges in low-income countries might limit the feasibility of effective HH, including preexisting knowledge gaps and staffing. Aim: We sought to evaluate the feasibility of the implementation of effective HH practice at a teaching hospital in Rwanda. Methods: We conducted a prospective quality improvement project in the intensive care unit (ICU) at the Kigali University Teaching Hospital. We collected data before and after an intervention focused on HH adherence as defined by the World Health Organization '5 Moments for Hand Hygiene' and assuring availability of HH supplies. Pre-intervention data were collected throughout July 2019, and HH measures were implemented in August 2019. Post-implementation data were collected following a 3-month wash-in. Results: In total, 902 HH observations were performed to assess pre-intervention adherence and 903 observations post-intervention adherence. Overall, HH adherence increased from 25% (222 of 902 moments) before intervention to 75% (677 of 903 moments) after intervention (P < 0.001). Improvement was seen among all health professionals (nurses: 19-74%, residents: 23-74%, consultants: 29-76%). Conclusions: Effective HH measures are feasible in an ICU in a low-income country. Ensuring availability of supplies and training appears key to effective HH practices.

Applying the Exploration Preparation Implementation Sustainment (EPIS) Framework to the Kigali Imbereheza Project for Rwandan Adolescents Living With HIV.

BACKGROUND: Sub-Saharan African adolescents living with HIV face challenges to antiretroviral therapy (ART) adherence. Poor mental health drives nonadherence but can be improved with cognitive behavioral therapy (CBT). CBT delivered by peers may strengthen effects while building capacity for sustainment in low-income countries. This case study retrospectively applied the Exploration Preparation Implementation Sustainment framework to characterize the execution of the Kigali Imbereheza Project, a 2-arm individually randomized group controlled trial of Trauma-Informed Adherence-Enhanced CBT (TI-CBTe) delivered by Rwandan youth leaders (YLs) to adolescents living with HIV. METHODS: YL (n = 14, 43% female, M = 22.71 years) had confirmed HIV and self-reported ART adherence >95%. Participants (n = 356, 51% female, M = 16.78 years) living with HIV were randomized to TI-CBTe or usual care. Two YLs co-led TI-CBTe sessions over 2 months for a total of 12 hours, while other YL observed and rated fidelity. Participants reported on YL competence. Additional data evaluated feasibility, acceptability, uptake, and fidelity. RESULTS: In the Exploration phase, focus groups, stakeholder meetings, and individual interviews revealed strong consensus for delivering TI-CBT to reduce adolescent depression and trauma and improve ART adherence. In the Preparation phase, curriculum revisions were made, YLs were successfully trained, and a cascading supervision model was established. In the Implementation phase, YL delivered TI-CBTe with close monitoring and supervision. Findings revealed strong feasibility, acceptability, uptake, and fidelity, increasing the likelihood of Sustainment. CONCLUSIONS: Exploration Preparation Implementation Sustainment can guide implementation planning and delivery and evaluate implementation outcomes.

Hepatitis B vaccination coverage among healthcare workers at a tertiary hospital in Rwanda.

OBJECTIVE: We evaluated post-vaccination immunity status and describe potential risk factors associated with the lack of response among healthcare workers (HCWs) at a tertiary care hospital in Kigali, Rwanda. RESULTS: Of 373 HCWs, 291 (78.2%) were female and 81 (21.8%) were male. The mean age of the study participants was 40.2 years (standard deviation [SD], 7.7 years), within a range of 24-41 years. Participants' mean BMI was 25.4 ± 6.6 kg/m2, with more than half of patients (60.3%) being overweight. 96% received all three doses of vaccination. A total of 36 participants (9.6%) were considered non responders as they did not develop a sufficient anti-HBs response post vaccination. The anti-HBs response was significantly higher in females when compared to males (p = 0.02). Interestingly, there was no significant association between decline in antibody levels with age (p = 0.242) and BMI (p = 0.516) of the participants. The anti-HBs titers were similar in the group of participants who had received two doses and those who had received three doses of the HBV vaccination. Overall the findings of our study provide a basis for testing for anti-HBs in all HCWs post vaccination in Rwanda.

Obstructive uropathy as initial presentation of genitourinary tuberculosis and masquerading as a postsurgical complication.

A 46-year-old woman who had a recent total abdominal hysterectomy presented with a 1 month history of lower abdominal pain, 1 week of nausea and vomiting as well as decreased urinary output preceded by a year of significant unintentional weight loss. On renal imaging, she was found to have bilateral hydronephrosis and hydroureters in the setting of bilateral distal ureteric obstruction complicated with acute kidney injury and severe hyperkalaemia requiring haemodialysis. The initial concern was for ureteric injury, a known complication of abdominal hysterectomy procedures, however, a urological intervention, performed 9 months later to relieve the ureteric obstruction, revealed purulent material within the left ureter that was smear positive for acid fast bacilli. A GeneXpert test was positive for Mycobacterium tuberculosis She was diagnosed with genitourinary tuberculosis and responded well to antitubercular treatment and haemodialysis was discontinued after the surgery relieved her ureteric obstruction.

High prevalence of antimicrobial resistance among common bacterial isolates in a tertiary healthcare facility in Rwanda.

Antimicrobial resistance (AMR) is a serious public health threat in both developed and developing countries. Many developing countries, including Rwanda, lack adequate surveillance systems, and therefore, the prevalence of AMR is not well-known. We conducted a prospective observational study to assess the prevalence of AMR among common bacterial isolates from clinical specimens obtained from patients on the medical wards of Kigali University Teaching Hospital (KUTH). We evaluated the antibiotic sensitivity patterns of bacterial pathogens cultured from urine, blood, sputum, and wound swab specimens obtained over a 6-month period (July 1 to December 30, 2013). There were 154 positive cultures from specimens obtained from 141 unique patients over the study period. Urine, blood, wound swab, and sputum cultures comprised 55.2%, 25.3%, 16.2%, and 3.3% of the total specimens evaluated; 31.4% and 58.7% of Escherichia coli and Klebsiella isolates, respectively, were resistant to at least one of the third generation cephalosporins. Eight percent of E. coli isolates were resistant to imipenem; 82% and 6% of Staphylococcus aureus strains were oxacillin- and vancomycin-resistant respectively. Antimicrobial resistance rates are high in Rwanda and pose a serious therapeutic challenge to the management of common infections.