Medicinal plants used for the management of respiratory diseases in Zimbabwe: Review and perspectives potential management of COVID-19.

Respiratory diseases have in the recent past become a health concern globally. More than 523 million cases of coronavirus disease (COVID19), a recent respiratory diseases have been reported, leaving more than 6 million deaths worldwide since the start of the pandemic. In Zimbabwe, respiratory infections have largely been managed using traditional (herbal) medicines, due to their low cost and ease of accessibility. This review highlights the plants' toxicological and pharmacological evaluation studies explored. It seeks to document plants that have been traditionally used in Zimbabwe to treat respiratory ailments within and beyond the past four decades. Extensive literature review based on published papers and abstracts retrieved from the online bibliographic databases, books, book chapters, scientific reports and theses available at Universities in Zimbabwe, were used in this study. From the study, there were at least 58 plant families comprising 160 medicinal plants widely distributed throughout the country. The Fabaceae family had the highest number of medicinal plant species, with a total of 21 species. A total of 12 respiratory ailments were reportedly treatable using the identified plants. From a total of 160 plants, colds were reportedly treatable with 56, pneumonia 53, coughs 34, chest pain and related conditions 29, asthma 25, tuberculosis and spots in lungs 22, unspecified respiratory conditions 20, influenza 13, bronchial problems 12, dyspnoea 7, sore throat and infections 5 and sinus clearing 1 plant. The study identified potential medicinal plants that can be utilised in future to manage respiratory infections.

The effect of increased mobility on SARS-CoV-2 transmission: a descriptive study of the trends of COVID-19 in Zimbabwe between December 2020 and January 2021.

INTRODUCTION: when the first cases of COVID-19 were reported in Zimbabwe in March 2020, the local outbreak was characterised by an insidious increase in national caseload. This first wave was mainly attributable to imported cases, peaking around July 2020. By October 2020, the number of cases reported daily had declined to less than 100 cases per day signalling the end of the first wave. This pattern mirrored the global trends. In December 2020, reports of new COVID-19 variants emerged and coincided with the beginning of the second wave within the ongoing pandemic. This paper reports on the analysis conducted on the new wave of COVID-19 beginning December 2020 to January 2021. The objective of this study was to document the evolving presumptive second wave of the COVID-19 pandemic in Zimbabwe from December 2020 to January 2021. METHODS: this is a retrospective analysis of secondary data extracted from the daily situation reports published by the Ministry of Health and Child Welfare, Zimbabwe and World Health Organization Country Office, Zimbabwe. The period under consideration started from 1st December 2020 to 31st January 2021. RESULTS: there was a 333% increase in the number of confirmed COVID-19 cases starting 1st December 2020, to 31st January 2021. These new cases were mainly attributed to community transmission though there were a few imported cases. There was a 439% increase in the absolute number of deaths; however, the case fatality rate remained low at 3.6%, and comparable to that from other countries. Harare, Bulawayo and Manical and provinces accounted for 60% of the case burden, with the other seven provinces only accounting for 40%. By mid-January, the number of incident COVID-19 cases started to decline significantly, to levels similar to the residual levels seen during the first wave. CONCLUSION: the second wave, which lasted a period of less than 2 months, had a steep rise and sharp decline in the incident cases and fatalities. The steep rise was attributable to increased mobility, with a consequent increase in the chains of community transmission. The declines, noted from mid-January 2021, may be partly attributable to a strict national lockdown, though more in-depth exploration of the drivers of transmission is needed to tailor effective interventions for future control. Differentiated strategies maybe needed according to the case burdens in the different provinces. In anticipation of further waves, the introduction of safe and effective vaccines might be the game changer if the vaccines are widely availed to the population to levels adequate to achieve herd immunity. Meanwhile, infection prevention and control guidelines must continue to be observed.

A descriptive study of the trends of COVID-19 in Zimbabwe from March-June 2020: policy and strategy implications.

INTRODUCTION: the first cases of COVID-19 were reported in China in December 2019. Since then, the disease has evolved to become a global pandemic. Zimbabwe reported its first case on 20th March 2020, and the number has been increasing steadily. However, Zimbabwe has not witnessed the exponential growth witnessed in other countries so far, and the trajectory seems different. We set out to describe the epidemiological trends of COVID-19 in Zimbabwe from when the first case was confirmed to June 2020. METHODS: data were collected from daily situation reports that were published by the Zimbabwean Ministry of Health and Child Care from 20th March to 27th June 2020. Missing data on the daily situation reports was not imputed. RESULTS: as of 27th June 2020, Zimbabwe had 567 confirmed COVID-19 cases. Eighty-two percent of these were returning residents and 18% were local transmission. The testing was heavily skewed towards returnees despite a comprehensive testing strategy. Of the confirmed cases, 142 were reported as recovered. However, demographic data for the cases were missing from the reports. It was not possible to estimate the probable period of infection of an active case, and case fatality in Zimbabwe was about 1% for the first 4 months of the pandemic. CONCLUSION: the epidemiological trends of COVID-19 experienced in Zimbabwe between March and June 2020 are somewhat different from what has been observed elsewhere. Further research to determine the reasons for the differences is warranted, to inform public health practice and tailor make suitable interventions.

Left ventricular hypertrophy detection from simple clinical measures combined with electrocardiographic criteria in a group of African ancestry.

BACKGROUND: Whether routine clinical parameters associated with left ventricular mass (LVM) enhance the performance of electrocardiographic (ECG) criteria for LV hypertrophy (LVH) detection and hence modify overall cardiovascular risk stratification is unknown. METHODS: An approach to echocardiographic LVH detection was identified from ECG criteria and clinical variables [age, body mass index (BMI), systolic blood pressure (SBP) and estimated glomerular filtration rate] associated with LVM in 621 participants of African ancestry. Performance (area under the receiver operating curve) and classification accuracy for LVH detection and the impact on cardiovascular risk stratification were determined. RESULTS: Compared to Cornell criteria alone, the combined use of Cornell criteria and clinical variables increased the performance (p < 0.001) and sensitivity (p < 0.05 to p < 0.0001) for LVH detection. The use of Cornell product together with additional clinical parameters as compared to Cornell product criteria alone increased the proportion of participants with pre-, grade I or grade II hypertension risk stratified as having a high added cardiovascular risk (56.3-67.9 %, p < 0.05). CONCLUSIONS: In individuals of African ancestry, a combination of Cornell product criteria and age, BMI and SBP improves classification accuracy of Cornell criteria for LVH and increases those identified as having a high added as compared to lower cardiovascular risk scores.

Relationship between glomerular dysfunction and left-ventricular mass independent of haemodynamic factors in a community sample.

AIM: To evaluate whether the relationship between early glomerular dysfunction and left-ventricular mass (LVM) occurs in a community sample and whether this relationship depends on haemodynamic factors. METHODS: In 621 randomly selected participants from a community sample (332 were normotensive), estimated glomerular filtration rate (eGFR), LVM and dimensions were determined using echocardiography, and aortic blood pressure (BP) assessed from applanation tonometry and SphygmoCor software. Aortic pulse wave velocity (PWV) and high-quality 24-h BP values were available from 554 and 437 participants, respectively. RESULTS: With adjustments for confounders (including clinic SBP), eGFR was associated with LVM index (LVMI) and LVM in excess of that predicted from stroke work (inappropriate LVM, LVMinappr) in all participants (LVMI: partial r = -0.18, P < 0.0001; LVMinappr: partial r = -0.17, P < 0.0001) and normotensive (LVMI: partial r = -0.23, P < 0.0001; LVMinappr: partial r = -0.22, P < 0.0001) separate from hypertensive patients. Marked differences in LVMinappr were noted in the eGFR range below 132 compared to at least 132 ml/min per 1.73 m (P < 0.0005). When replacing clinic BP with either aortic SBP, 24-h BP, PWV, stroke work (for LVMI), left-ventricular end-diastolic diameter (LVEDD), or circumferential wall stress in the regression models, eGFR retained strong associations with LVMI (P = 0.01 to <0.0001) and LVMinappr (P < 0.005 to <0.0001) and these effects were replicated in normotensive separate from hypertensive patients. CONCLUSIONS: Strong relationships between eGFR and LVM occur at a community level irrespective of the presence of hypertension and independent of 24-h and aortic BP, PWV, LVEDD, stroke work and wall stress. Non-haemodynamic factors explain a considerable proportion of the relationship between early glomerular dysfunction and left-ventricular hypertrophy.

Relationship between inappropriate left ventricular hypertrophy and ejection fraction independent of absolute or indexed mass in a community sample of black African ancestry.

AIM: We determined whether left ventricular hypertrophy (LVH) which exceeds that predicted from workload [inappropriate LV mass (LVM(inappr))] is associated with reduced left ventricle (LV) systolic chamber function independent of and more closely than absolute or indexed left ventricular mass (LVM). METHODS: In 626 randomly selected adult participants from a community sample of black Africans, using echocardiography we assessed absolute LVM, LVM indexed to height(2.7) (LVMI), LVM(inappr), LV wall stress, ejection fraction, and midwall fractional shortening (FSmid). LVM(inappr) was determined as percentage of observed/predicted LVM. Predicted LVM was calculated from a previously validated formula that incorporates stroke work. LVMI(inappr) more than 150% was considered to be inappropriate LVH. This threshold was identified from the upper 95% confidence interval for LVMI(inappr) determined in 140 healthy participants. RESULTS: A total of 21.7% of participants had LVH (LVMI > 51 g/m(2.7)) and 18.5% had inappropriate LVH. With adjustments for LV stress and other confounders there was a strong inverse relationship between LVM(inappr) and ejection fraction (partial r = -0.41, P < 0.0001), whereas only modest inverse relations between LVM or LVMI and ejection fraction were noted (partial r = -0.07 to -0.09, P < 0.05-0.09) (P < 0.0001, comparison of partial r values). The independent relationship between LVM(inappr) and ejection fraction persisted with further adjustments for LVM or LVMI (partial r = -0.52, P < 0.0001). LVM(inappr) and FSmid were similarly inversely related (P < 0.0001) and these relations were also stronger and independent of LVM or LVMI. CONCLUSION: Inappropriate LVH is strongly and inversely related to variations in ejection fraction independent of and more closely than LVM or LVMI in a community sample of black African ancestry. These data suggest that LVH is a compensatory response to workload, but when exceeding that predicted by workload, is associated with LV systolic chamber decompensation.

Obesity markedly attenuates the validity and performance of all electrocardiographic criteria for left ventricular hypertrophy detection in a group of black African ancestry.

AIM: To assess the impact of obesity on the validity and performance of electrocardiographic criteria for the detection of left ventricular hypertrophy (LVH) in a group of participants of black African ancestry with a high prevalence of obesity. METHODS: Electrocardiographic voltage criteria for the detection of echocardiographic LVH [left ventricular mass index (LVMI) >51 g/m²·7] were evaluated in 661 participants from a community sample of black African ancestry (43% obese). RESULTS: BMI was inversely associated with Sokolow-Lyon voltages (partial r= -0.27, P < 0.0001) and no BMI-Cornell voltage relations were noted (P = 0.21). BMI was associated with voltage criteria that incorporate only limb lead recordings (r = 0.17-0.23), but these relations were weaker than BMI-LVMI relations (r = 0.36, P < 0.01 and P < 0.0001 for comparisons of r values). All electrocardiographic criteria were as strongly related to blood pressure as LVMI. Sokolow-Lyon voltage-LVMI relations were noted only after adjustments for BMI (P < 0.02) and Sokolow-Lyon voltages showed no performance for LVH detection. Cornell voltages showed significant performance in nonobese [area under receiver operating curve (AUC) = 0.67 ± 0.04, P < 0.0005], but not in obese (AUC = 0.56 ± 0.04, P = 0.08). Electrocardiographic criteria which employ limb-lead recordings only (e.g. RaVL) showed better performance in nonobese than in obese (AUC = 0.75 ± 0.04 and 0.59 ± 0.04, respectively, P < 0.005 for comparison) and markedly reduced specificity for LVH detection in obese (76%) than in nonobese (92%, P < 0.0001) despite similar sensitivities (32 vs. 29%). CONCLUSION: In groups of black African ancestry, obesity contributes to a poor validity and performance of all voltage criteria for the detection of LVH. None of the current criteria are recommended for use in obesity.