Optimizing Network Connectivity for Mobile Health Technologies in sub-Saharan Africa

Background: Mobile health (mHealth) technologies hold incredible promise to improve healthcare delivery in resource-limited settings. Network reliability across large catchment areas can be a major challenge. We performed an analysis of network failure frequency as part of a study of real-time adherence monitoring in rural Uganda. We hypothesized that the addition of short messaging service (SMS+GPRS) to the standard cellular network modality (GPRS) would reduce network disruptions and improve transmission of data. Methods: Participants were enrolled in a study of real-time adherence monitoring in southwest Uganda. In June 2011, we began using Wisepill devices that transmit data each time the pill bottle is opened. We defined network failures as medication interruptions of >48 hours duration that were transmitted when network connectivity was re-established. During the course of the study, we upgraded devices from GPRS to GPRS+SMS compatibility. We compared network failure rates between GPRS and GPRS+SMS periods and created geospatial maps to graphically demonstrate patterns of connectivity. Results: One hundred fifty-seven participants met inclusion criteria of seven days of SMS and seven days of SMS+GPRS observation time. Seventy-three percent were female, median age was 40 years (IQR 33–46), 39% reported >1-hour travel time to clinic and 17% had home electricity. One hundred one had GPS coordinates recorded and were included in the geospatial maps. The median number of network failures per person-month for the GPRS and GPRS+SMS modalities were 1.5 (IQR 1.0–2.2) and 0.3 (IQR 0–0.9) respectively, (mean difference 1.2, 95%CI 1.0–1.3, p-value<0.0001). Improvements in network connectivity were notable throughout the region. Study costs increased by approximately $1USD per person-month. Conclusions: Addition of SMS to standard GPRS cellular network connectivity can significantly reduce network connection failures for mobile health applications in remote areas. Projects depending on mobile health data in resource-limited settings should consider this upgrade to optimize mHealth applications

Prevalence of lower extremity Peripheral artery disease among adult diabetes patients in Southwestern Uganda

Background: Peripheral artery disease (PAD) is a major complication of atherosclerosis. PAD can be diagnosed with low-cost diagnostic techniques and is associated with significant morbidity and mortality. While the major epidemiologic risk factors for PAD have been established in the western world, data from resource-poor countries are limited. We performed a cross-sectional study to determine the prevalence and correlates of PAD among patients with diabetes at Mbarara Referral Hospital in southwestern Uganda. Methods: We consecutively enrolled diabetes patients aged 50 years or greater presenting to the outpatient clinic. We collected blood for fasting lipid profile, HIV serology, and glycosylated hemoglobin, measured blood pressure and ankle brachial index, and administered the Edinburgh Claudication Questionnaire (ECQ). We also surveyed patients for other PAD risk factors. We used logistic regression to determine correlates of PAD. Results: We enrolled 229 diabetes patients. The median age of 60 years (IQR 55–66), and 146 (63.7%) were female. Fifty five patients (24%) had PAD (ABI of ≤ 0.9). Of these, 48 /55 (87.27%) had mild PAD (ABI 0.71-0.9) while 7/55 (12.73%) had moderate to severe PAD (ABI < 0.7). Amongst those with PAD, 24/55 (43.64%) reported claudication by the ECQ. Correlates of PAD included female sex (AOR 2.25, 95% CI 1.06 - 4.77, p = 0.034), current high blood pressure (AOR 2.59, 95% CI 1.25-5.33, p = 0.01), and being on a sulfonylurea–glibenclamide (AOR 3.47, 95% CI 1.55 - 7.76, p = 0.002). Conclusion: PAD was common in diabetic patients in southwestern Uganda. Given its low cost and ease of measurement, ABI deserves further assessment as a screening tool for both PAD and long term cardiovascular risk amongst diabetics in this region

Malaria is an uncommon cause of adult sepsis in south-western Uganda

Malaria is often considered a cause of adult sepsis in malaria endemic areas. However, diagnostic limitations can make distinction between malaria and other infections challenging. Therefore, the objective of this study was to determine the relative contribution of malaria to adult sepsis in south-western Uganda

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Incidence and predictors of hypertension in adults with HIV-initiating antiretroviral therapy in south-western Uganda

ObjectiveThe successful scale-up of antiretroviral therapy (ART) in sub-Saharan Africa has led to increasing life expectancy, and thus increased risk of hypertension. We aimed to describe the incidence and predictors of hypertension in HIV patients receiving ART at a publicly funded clinic in rural Uganda.MethodsWe abstracted data from medical records of adult patients who initiated ART at an HIV clinic in south-western Uganda during 2010-2012. We defined hypertension as at least two consecutive clinical visits, with a SBP at least 140 mmHg and/or SBP of at least 90 mmHg, or prescription for an antihypertensive medication. We calculated the incidence of hypertension and fit multivariable Cox proportional-hazards models to identify predictors of hypertension.ResultsA total of 3389 patients initiated ART without a prior diagnosis of hypertension during the observation period. Over 3990 person-years of follow-up, 445 patients developed hypertension, for a crude incidence of 111.5/1000 (95% confidence interval 101.9-121.7) person-years. Rates were highest among men aged at least 40 years (158.8 per/1000 person-years) and lowest in women aged 30-39 years (80/1000 person-years). Lower CD4 cell count at ART initiation, as well as traditional risk factors including male sex, increasing age, and obesity, were independently associated with hypertension.ConclusionWe observed a high incidence of hypertension in HIV-infected persons on ART in rural Uganda, and increased risk with lower nadir CD4 cell counts. Our findings call for increased attention to screening of and treatment for hypertension, along with continued prioritization of early ART initiation

Measuring Post-Partum Haemorrhage in Low-Resource Settings: The Diagnostic Validity of Weighed Blood Loss versus Quantitative Changes in Hemoglobin

Background: Accurate estimation of blood loss is central to prompt diagnosis and management of post-partum hemorrhage (PPH), which remains a leading cause of maternal mortality in low-resource countries. In such settings, blood loss is often estimated visually and subjectively by attending health workers, due to inconsistent availability of laboratory infrastructure. We evaluated the diagnostic accuracy of weighed blood loss (WBL) versus changes in peri-partum hemoglobin to detect PPH. Methods: Data from this analysis were collected as part of a randomized controlled trial comparing oxytocin with misoprostol for PPH (NCT01866241). Blood samples for complete blood count were drawn on admission and again prior to hospital discharge or before blood transfusion. During delivery, women were placed on drapes and had pre-weighed sanitary towels placed around their perineum. Blood was then drained into a calibrated container and the sanitary towels were added to estimate WBL, where each gram of blood was estimated as a milliliter. Sensitivity, specificity, negative and positive predictive values (PPVs) were calculated at various blood volume loss and time combinations, and we fit receiver-operator curves using blood loss at 1, 2, and 24 hours compared to a reference standard of haemoglobin decrease of >10%. Results: A total of 1,140 women were enrolled in the study, of whom 258 (22.6%) developed PPH, defined as a haemoglobin drop >10%, and 262 (23.0%) had WBL ≥500mL. WBL generally had a poor sensitivity for detection of PPH (85%) in high prevalence settings when WBL exceeds 750mL. Conclusion: WBL has poor sensitivity but high specificity compared to laboratory-based methods of PPH diagnosis. These characteristics correspond to a high PPV in areas with high PPH prevalence. Although WBL is not useful for excluding PPH, this low-cost, simple and reproducible method is promising as a reasonable method to identify significant PPH in such settings where quantifiable red cell indices are unavailable

An analysis of stroke risk factors by HIV serostatus in Uganda: Implications for stroke prevention in sub-Saharan Africa

ObjectiveHIV infection is an important stroke risk factor in sub-Saharan Africa.&nbsp; However, data on stroke risk factors in the era of antiretroviral therapy (ART) are sparse. We aimed to determine if stroke risk factors differed by HIV serostatus in Uganda.MethodsWe conducted a matched cohort study, enrolling persons living with HIV (PWH) with acute stroke, matched by sex and stroke type to HIV uninfected (HIV-) individuals. We collected data on stroke risk factors and fitted logistic regression models for analysis.ResultsWe enrolled 262 participants:105 PWH and 157 HIV-. The median ART duration was 5 years, and the median CD4 cell count was 214 cells/uL. PWH with ischemic stroke had higher odds of hypertriglyceridemia (AOR 1.63; 95% CI 1.04, 2.55, p=0.03), alcohol consumption (AOR 2.84; 95% CI 1.32, 6.14, p=0.008), and depression (AOR 5.64; 95%CI 1.32, 24.02, p=0.02) while HIV- persons with ischemic stroke were more likely to be &gt; 55 years of age (AOR 0.43; 95%CI 0.20-0.95, p=0.037), have an irregular heart rhythm (AOR 0.31; 95%CI 0.10-0.98, p=0.047) and report low fruit consumption (AOR 0.39; 95%CI 0.18-0.83, p=0.014).&nbsp; Among all participants with hemorrhagic stroke (n=78) we found no differences in the prevalence of risk factors between PWH and HIV-.ConclusionsPWH with ischemic stroke in Uganda present at a younger age, and with a combination of traditional and psychosocial risk factors. By contrast, HIV- persons more commonly present with arrhythmia. A differential approach to stroke prevention might be needed in these populations

Negative and positive predictive values of blood loss measurement by weight method versus a reference standard of >10% drop in haemoglobin.

<p>Negative and positive predictive values of blood loss measurement by weight method versus a reference standard of >10% drop in haemoglobin.</p

Measurement of PPH by haemoglobin drop and measured blood loss.

<p>Measurement of PPH by haemoglobin drop and measured blood loss.</p

ROC curves comparing measured blood loss and Hb drop (standard) at different time points.

<p>ROC curves comparing measured blood loss and Hb drop (standard) at different time points.</p