Effects of Proximity to Roads on Tissue Surface PH, Conductivity and Heavy Metal Contents of a Grazing Grass Species

Globally, road networks are expanding in the countryside. Though beneficial to society, the roads potentially have detrimental effects on grazing quality. The effects are seldom quantified. In this study Eragrostis lehmanniana, a common native grazing grass in parts of the world, was examined for indicative data on the impacts of roads on grasses. Aboveground tissue samples were collected monthly on three occasions during the growing season, at the same respective locations near three high traffic highways. Non-senescent specimens were sampled along transects of up to 400 m perpendicular to the highways, starting from the road edge and then at intervals of at least 10 m. Concurrent control samples were collected at a site more than 3 km from a road. In the laboratory, a whole stem of each specimen was washed in 40 ml of distilled water, whose pH and electrical conductivity were then measured. Heavy metal concentrations (HMC) in dry grass tissue were determined using ICP-MS analysis. Consistently, tissue surface pH was lower, and electrical conductivity higher, close to the road edge than farther away. Heavy metal concentrations were high close to the road edge, some (Fe, Ni) beyond the tolerable limits of cattle and gazelle-like grazers. Using the respective control site means as thresholds, linear regression of pH and conductivity against distance showed that the effects were pronounced for 70 m – 600 m from the road edge. The low pH was due to acidity caused by motor vehicle- emmited nitrogen and sulpher oxides (NOx, SOx) reacting with atmospheric water vapour. High conductivity and HMC were judged to be due to motor vehicle-sourced metal elements and particulate matter. Spacing roads at least 1.2 km apart in grazing areas is recommended to reduce the detrimental effects

HIV in Children in a General Population Sample in East Zimbabwe: Prevalence, Causes and Effects

There are an estimated half-million children living with HIV in sub-Saharan Africa. The predominant source of infection is presumed to be perinatal mother-to-child transmission, but general population data about paediatric HIV are sparse. We characterise the epidemiology of HIV in children in sub-Saharan Africa by describing the prevalence, possible source of infection, and effects of paediatric HIV in a southern African population.From 2009 to 2011, we conducted a household-based survey of 3389 children (aged 2-14 years) in Manicaland, eastern Zimbabwe (response rate: 73.5%). Data about socio-demographic correlates of HIV, risk factors for infection, and effects on child health were analysed using multi-variable logistic regression. To assess the plausibility of mother-to-child transmission, child HIV infection was linked to maternal survival and HIV status using data from a 12-year adult HIV cohort.HIV prevalence was (2.2%, 95% CI: 1.6-2.8%) and did not differ significantly by sex, socio-economic status, location, religion, or child age. Infected children were more likely to be underweight (19.6% versus 10.0%, p = 0.03) or stunted (39.1% versus 30.6%, p = 0.04) but did not report poorer physical or psychological ill-health. Where maternal data were available, reported mothers of 61/62 HIV-positive children were deceased or HIV-positive. Risk factors for other sources of infection were not associated with child HIV infection, including blood transfusion, vaccinations, caring for a sick relative, and sexual abuse. The observed flat age-pattern of HIV prevalence was consistent with UNAIDS estimates which assumes perinatal mother-to-child transmission, although modelled prevalence was higher than observed prevalence. Only 19/73 HIV-positive children (26.0%) were diagnosed, but, of these, 17 were on antiretroviral therapy.Childhood HIV infection likely arises predominantly from mother-to-child transmission and is associated with poorer physical development. Overall antiretroviral therapy uptake was low, with the primary barrier to treatment appearing to be lack of diagnosis

Nursing and community rates of Mycobacterium tuberculosis infection among students in Harare, Zimbabwe.

BACKGROUND: African hospitals have experienced major increases in admissions for tuberculosis, but they are ill-equipped to prevent institutional transmission. We compared institutional rates and community rates of tuberculin skin test (TST) conversion in Harare, Zimbabwe. METHODS: We conducted a cohort study of TST conversion 6, 12, and 18 months into training among 159 nursing and 195 polytechnic school students in Harare. Students had negative TST results (induration diameter, or =10 mm) per 100 person-years (95% confidence interval [CI], 14.2-26.2 conversions per 100 person-years), and polytechnic school students experienced 6.0 (95% CI, 3.5-10.4) conversions per 100 person-years. The rate of difference was 13.2 conversions (95% CI, 6.5-20.0) per 100 person-years. With a more stringent definition of conversion (increase in the induration diameter of > or =10 mm to at least 15 mm), which is likely to increase specificity but decrease sensitivity, conversion rates were 12.5 and 2.8 conversions per 100 person-years in nursing and polytechnic school students, respectively (rate difference, 9.7 conversions per 100 person-years; 95% CI, 4.5-14.8 conversions per 100 person-years). Nursing students reportedly nursed 20,868 inpatients with tuberculosis during 315 person-years of training. CONCLUSIONS: Both groups had high TST conversion rates, but the extremely high rates among nursing students imply high occupational exposure to Mycobacterium tuberculosis. Intense exposure to inpatients with tuberculosis was reported during training. Better prevention, surveillance, and management of institutional M. tuberculosis transmission need to be supported as part of the international response to the severe human immunodeficiency virus infection epidemic and health care worker crisis in Africa

Cardiac Disease in Adolescents With Delayed Diagnosis of Vertically Acquired HIV Infection

Background. At least one-third of human immunodeficiency virus (HIV)–infected infants survive to adolescence even without antiretroviral therapy (ART), but are at high risk of complications including cardiac disease. We investigated the characteristics of cardiac disease among adolescents with HIV infection diagnosed in late childhood who were receiving ambulatory HIV care in Harare, Zimbabwe. / Methods. Consecutive adolescents with vertically acquired HIV attending 2 HIV outpatient treatment clinics were studied. Assessment included clinical history and examination, and 2-dimensional, M-mode, pulsed- and continuous-wave Doppler echocardiography. / Results. Of 110 participants (47% male; median age, 15 years; interquartile range, 12–17 years), 78 (71%) were taking ART. Exertional dyspnea, chest pain, palpitations, and ankle swelling were reported by 47 (43%), 43 (39%), 10 (9%), and 7 (6%), respectively. The New York Heart Association score was ≥2 in 41 participants (37%). Echocardiography showed that 74 participants (67%) had left ventricular (LV; septal and/or free wall) hypertrophy and 27 (24%) had evidence of impaired LV relaxation or restrictive LV physiology. The estimated pulmonary artery systolic pressure (ePASP) was >30 mm Hg in 4 participants (3.6%); of these 2 also had right ventricular (RV) dilatation. Another 32 participants (29%), without elevated ePASP, had isolated RV dilatation. / Conclusions. A significant burden of cardiac disease was seen among adolescents with vertically acquired HIV infection. More than half were asymptomatic yet had significant echocardiographic abnormalities. These findings highlight the need to screen this population in order to better define the geography, natural history, etiopathogenic mechanisms, and management (including the timing and choice of optimal therapeutic ART and cardiac drug interventions) to prevent development and/or progression of HIV-associated cardiac disease

Provider-initiated symptom screening for tuberculosis in Zimbabwe: diagnostic value and the effect of HIV status.

OBJECTIVE: To assess the diagnostic value of provider-initiated symptom screening for tuberculosis (TB) and how HIV status affects it. METHODS: We performed a secondary analysis of randomly selected participants in a community-based TB-HIV prevalence survey in Harare, Zimbabwe. All completed a five-symptom questionnaire and underwent sputum TB culture and HIV testing. We calculated the sensitivity, specificity, and positive and negative predictive values of various symptoms and used regression analysis to investigate the relationship between symptoms and TB disease. FINDINGS: We found one or more symptoms of TB in 21.2% of 1858 HIV-positive (HIV+) and 9.9% of 7121 HIV-negative (HIV-) participants (P or = 2 weeks' duration, any symptom and a positive sputum culture had sensitivities of 48%, 81% and 65%, respectively; in HIV- participants, the sensitivities were 45%, 71% and 74%, respectively. Symptoms had a similar sensitivity and specificity in HIV+ and HIV- participants, but in HIV+ participants they had a higher positive and a lower negative predictive value. CONCLUSION: Even smear-positive TB may be missed by provider-initiated symptom screening, especially in HIV+ individuals. Symptom screening is useful for ruling out TB, but better TB diagnostics are urgently needed for resource-poor settings

The Risk and Timing of Tuberculosis Diagnosed in Smear-Negative TB Suspects: A 12 Month Cohort Study in Harare, Zimbabwe

BACKGROUND: Cases of smear-negative TB have increased dramatically in high prevalence HIV settings and pose considerable diagnostic and management challenges. METHODS AND FINDINGS: Between February 2006 and July 2007, a cohort study nested within a cluster-randomised trial of community-based case finding strategies for TB in Harare, Zimbabwe was undertaken. Participants who had negative sputum smears and remained symptomatic of TB were follow-up for one year with standardised investigations including HIV testing, repeat sputum smears, TB culture and chest radiography. Defaulters were actively traced to the community. The objectives were to investigate the incidence and risk factors for TB. TB was diagnosed in 218 (18.2%) participants, of which 39.4% was bacteriologically confirmed. Most cases (84.2%) were diagnosed within 3 months, but TB incidence remained high thereafter (111.3 per 1000 person-years, 95% CI: 86.6 to 146.3). HIV prevalence was 63.3%, and HIV-infected individuals had a 3.5-fold higher risk of tuberculosis than HIV-negative individuals. CONCLUSION: We found that diagnosis of TB was insensitive and slow, even with early radiography and culture. Until more sensitive and rapid diagnostic tests become widely available, a much more proactive and integrated approach towards prompt initiation of ART, ideally from within TB clinics and without waiting for TB to be excluded, is needed to minimise the risk and consequences of diagnostic delay

Evaluation of weight-based prescription of antiretroviral therapy in children.

OBJECTIVES: The aim of the study was to investigate the extent of and factors associated with incorrect dosing of antiretroviral therapy (ART) in HIV-infected children in Harare, Zimbabwe. METHODS: All children aged 0-10 years and children aged 11-17 years who weighed < 35 kg and taking ART were recruited from the paediatric HIV clinic at Harare Hospital. Their current doses of ART drugs were compared against doses recommended by the national guidelines. RESULTS: Among 309 children recruited [55% male; median age 7 years (interquartile range (IQR) 5-10 years)], the median CD4 count was 899 cells/μL and the median duration of their current ART regimen was 11.2 months (IQR 4.9-17.1 months). Overall, 110 (35.6%) children were prescribed incorrect doses of at least one drug component within their ART regimen; 64 (20.7%) under-dosed and 49 (15.9%) over-dosed on at least one drug. Children receiving a higher than recommended dose of at least one drug were younger compared with correctly dosed children (median 6 versus 7 years, respectively; P = 0.001), had been on their current ART regimen for a shorter time (median 7.2 versus 13 months, respectively; P = 0.003) and were less likely to be receiving a three-drug fixed-dose combination (FDC; 42.9 versus 63.3%, respectively; P = 0.009). Those who were under-dosed were also less likely to be on a three-drug FDC (25 versus 63.3%, respectively; P < 0.001). CONCLUSIONS: Over a third of children were prescribed incorrect doses of ART. Children taking triple-drug FDCs were likely to be correctly dosed. Our study highlights the importance of weight monitoring at each clinical contact, training of health care providers on paediatric drug dosing and the need for wider availability of FDCs for children

A comparison of HIV outpatient care in primary and secondary healthcare-level settings in Zimbabwe.

SETTING: Decentralisation of HIV care to nurse-led primary care services is being implemented across low- and middle-income countries in sub-Saharan Africa. OBJECTIVE: To compare services offered to clients attending for HIV care at a physician-led and a nurse-led service in Harare, Zimbabwe. DESIGN: A cross-sectional study was performed at Harare Central Hospital (HCH) and Budiriro Primary Care Clinic (PCC) from June to August 2018. An interviewer-administered questionnaire was used to collect sociodemographics, HIV treatment and clinical history from clients attending for routine HIV care. The Mann-Whitney U-test was used to evaluate for differences between groups for continuous variables. For categorical variables, the χ2 test was used. RESULTS: The median age of the 404 participants recruited was 38 years (IQR 28-47); 69% were female. Viral suppression was comparable between sites (HCH, 70% vs. PCC, 80%; P = 0.07); however, screening for comorbidities such as cervical cancer screening (HCH, 61% vs. PCC, 41%; P = 0.001) and provision of referral services (HCH, 23% vs. PCC, 13%; P = 0.01) differed between sites. CONCLUSION: Efforts to improve service provision in primary care settings are needed to ensure equity for users of health services

Echocardiographic reference ranges in older children and adolescents in sub-Saharan Africa.

BACKGROUND: Echocardiographic reference ranges are important to identify abnormalities of cardiac dimensions. Reference ranges for children in sub-Saharan Africa have not been established. The aim of this study was to establish echocardiographic z-score references for Black children in sub-Saharan Africa. METHODS: 282 healthy subjects aged 6-16years (143 [51%] males) with no known history of cardiac disease were enrolled in the study in Harare, Zimbabwe between 2014 and 2016. Standard M-mode echocardiography was performed and nine cardiac chamber dimensions were obtained. Two non-linear statistical models (gamma weighted model and cubic polynomial model) were tested on the data and the best fitting model was used to calculate z-scores of these cardiac chamber measures. The reference ranges are presented on scatter plots against BSA. RESULTS: Normative data for the following cardiac measures were obtained and z-scores calculated: right ventricular diameter at end diastole (RVEDD); left ventricular diameter at end diastole (LVEDD) and systole (LVESD); interventricular septal wall thickness at end diastole (IVSd) and systole (IVSs); left ventricular posterior wall thickness at end diastole (LVPWd) and systole (LVPWs); left atrium diameter at end systole (LA) and tricuspid annular plane systolic excursion (TAPSE). Girls had higher values for BMI and heart rate than boys (p=0.048 and p=0.001, respectively). Mean interventricular septal and left ventricular posterior walls thickness was higher than published normal values in predominantly Caucasian populations. CONCLUSION: These are the first echocardiographic reference ranges for children from sub Saharan Africa and will allow accurate assessment of cardiac dimensions in clinical practice