Comparison of deltamethrin as indoor residual spray or on insecticide treated nets for mosquito control in Lake Chilwa

We conducted a study on the control of mosquitos on Chisi Island in Lake Chilwa from August to November, 2006. The aim was to compare the cost and efficacy of deltamethrin, a pyrethroid based insecticide, when used in insecticide treated nets (ITN) and when used in indoor residual spray (IRS). Thirty village huts were enrolled in the study. Fifteen were systematically selected in a stratified manner and sprayed with deltamethrin following manufacturers' standard application procedures of 0.02g/m2. The remaining fifteen were provided with ITNs. In both groups deltamethrin KO tabs were used. Pyrethroid knockdown (PKD) spray was used for indoor rest captures in the houses monthly for three months. Houses treated with IRS had significantly reduced number of mosquitoes resting indoors than houses provided with nets (

Hydro-Physicochemical Changes in Domasi River Associated with Outbreak of Blackflies (Diptera; Simuliidae) in Zomba, Malawi

Blackflies impact human and animal health due to their biting nuisance and transmission of Ochocerca volvulus. This study presents an attempt to analyze hydro physicochemical changes associated with outbreak of black flies in Zomba, Malawi. The study compared historical data of hydro physicochemical parameters before (1985-2002) and after (2008) the outbreak to deduce the changes associated with mass occurrence of these flies. Changes in water quality between these two periods were assessed using T-tests. To establish the relationship between the black fly larval densities and water quality parameters data was subjected to both principal component and correlation analysis. Three principal components before the outbreak and two principal components during the outbreak (both dry and wet season) accounted for most of the variation in water quality in this river system. Nutrient load, increases in Total Suspended Solids (TSS) and Total Hardness (TH) were the main factors that had high loadings on these principal components over the years. A significant correlation was established between black fly larval densities and total hardness (r=0.86, p<0.05) as well as total suspended solids (r = 0.755, p<0.02). The potential role of anthropogenic influences on water quality and its cascading effect on black fly population dynamics is discussed

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

Delivery of index-linked HIV testing for children: learnings from a qualitative process evaluation of the B-GAP study in Zimbabwe

Background Index-linked HIV testing for children, whereby HIV testing is offered to children of individuals living with HIV, has the potential to identify children living with undiagnosed HIV. The “Bridging the Gap in HIV Testing and Care for Children in Zimbabwe” (B-GAP) study implemented and evaluated the provision of index-linked HIV testing for children aged 2–18 years in Zimbabwe. We conducted a process evaluation to understand the considerations for programmatic delivery and scale-up of this strategy. Methods We used implementation documentation to explore experiences of the field teams and project manager who delivered the index-linked testing program, and to describe barriers and facilitators to index-linked testing from their perspectives. Qualitative data were drawn from weekly logs maintained by the field teams, monthly project meeting minutes, the project coordinator’s incident reports and WhatsApp group chats between the study team and the coordinator. Data from each of the sources was analysed thematically and synthesised to inform the scale-up of this intervention. Results Five main themes were identified related to the implementation of the intervention: (1) there was reduced clinic attendance of potentially eligible indexes due to community-based differentiated HIV care delivery and collection of HIV treatment by proxy individuals; (2) some indexes reported that they did not live in the same household as their children, reflecting the high levels of community mobility; (3) there were also thought to be some instances of ‘soft refusal’; (4) further, delivery of HIV testing was limited by difficulties faced by indexes in attending health facilities with their children for clinic-based testing, stigma around community-based testing, and the lack of familiarity of indexes with caregiver provided oral HIV testing; (5) and finally, test kit stockouts and inadequate staffing also constrained delivery of index-linked HIV testing. Conclusions There was attrition along the index-linked HIV testing cascade of children. While challenges remain at all levels of implementation, programmatic adaptations of index-linked HIV testing approaches to suit patterns of clinic attendance and household structures may strengthen implementation of this strategy. Our findings highlight the need to tailor index-linked HIV testing to subpopulations and contexts to maximise its effectiveness

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

Common mental health and emotional and behavioural disorders among adolescents and young adults in Harare and Mashonaland East, Zimbabwe: a population-based prevalence study.

OBJECTIVES: To estimate the prevalence of common mental health disorders (CMDs) and emotional and behavioural disorders among young people and to explore the correlates of CMDs risk. SETTING: Five urban and periurban communities in Harare and Mashonaland East, Zimbabwe DESIGN: Population-based cross-sectional study PARTICIPANTS: Young people aged 13-24 years living in households in the study areas. OUTCOME MEASURES: The primary outcome was the proportion of participants screening positive for probable CMDs defined as a Shona Symptoms Questionnaire (SSQ) score ≥8. Secondary outcomes were emotional and behavioural disorders measured using the Strength and Difficulties Questionnaire (SDQ), and adjusted ORs for factors associated with CMD. RESULTS: Out of 634 young people, 37.4% (95% CI 33.0% to 42.0%) screened positive for probable CMDs, 9.8% (95% CI 7.5% to 12.7%) reported perceptual symptoms and 11.2% (95% CI 9.0% to 13.8%) reported suicidal ideation. Using UK norms to define normal, borderline and abnormal scores for each of the SDQ domains, a high proportion (15.8%) of Zimbabwean young people had abnormal scores for emotional symptoms and a low proportion had abnormal scores for hyperactivity/inattention scores (2.8%) and prosocial scores (7.1%). We created local cut-offs for the emotional symptoms, hyperactivity/attention and prosocial SDQ domains. The odds of probable CMDs increased with each year of age (OR 1.09, p<0.001) and was higher among those who were out of school and not working compared with those in school or working (adj. OR 1.67 (1.07, 2.62), p=0.04). One in five participants (22.1%) were referred immediately for further clinical assessment but uptake of referral services was low. CONCLUSIONS: We observed a high prevalence of symptoms of CMDs among general population urban and peri-urban young people especially among those with no employment. There is a need for more accessible and acceptable youth-friendly mental health services

History of tuberculosis is associated with lower exhaled nitric oxide levels in HIV-infected children

Objective: HIV disrupts host defense mechanisms and maintains chronic inflammation in the lung. Nitric oxide is a marker of lung inflammation and can be measured in the exhaled air. We investigated the relationship between exhaled nitric oxide (eNO), HIV status and airway abnormalities in perinatally HIV-infected children aged 6–19 years. Design: A cross-sectional study. Methods: HIV-infected individuals on antiretroviral therapy and HIV-uninfected children with no active tuberculosis (TB) or acute respiratory tract infection were recruited from a public hospital in Harare, Zimbabwe. Clinical history was collected and eNO testing and spirometry was performed. The association between eNO and explanatory variables (HIV, FEV1 z-score, CD4+ cell count, viral load, history of TB) was investigated using linear regression analysis adjusted for age, sex and time of eNO testing. Results: In total, 222 HIV-infected and 97 HIV-uninfected participants were included. Among HIV-infected participants, 57 (25.7%) had a history of past TB; 56 (25.2%) had airway obstruction, but no prior TB. HIV status was associated with lower eNO level [mean ratio 0.79 (95% confidence interval, 95% CI 0.65–0.97), P = 0.03]. Within the HIV-infected group, history of past TB was associated with lower eNO levels after controlling for age, sex and time of eNO testing [0.79 (95% CI 0.67–0.94), P = 0.007]. Conclusion: HIV infection and history of TB were associated with lower eNO levels. eNO levels may be a marker of HIV and TB-induced alteration in pulmonary physiology; further studies focused on potential causes for lower eNO levels in HIV and TB are warranted

Exhaled nitric oxide is associated with inflammatory biomarkers and risk of acute respiratory exacerbations in children with HIV‐associated chronic lung disease

Objectives Chronic lung disease is a recognized complication in children with HIV. Acute respiratory exacerbations (ARE) are common among this group and cause significant morbidity. Exhaled nitric oxide (eNO) is a known marker of local airway inflammation. We investigated the association between eNO and ARE, biomarkers of systemic inflammation, and the effect of azithromycin on eNO levels. Methods Individuals aged 6–19 years with HIV-associated chronic lung disease in Harare, Zimbabwe, were enrolled in a placebo-controlled randomized trial investigating the effect of 48-week azithromycin treatment on lung function and ARE. eNO levels and biomarkers were measured at inclusion and after treatment in a consecutively enrolled subset of participants. Linear regression and generalized linear models were used to study associations between eNO and ARE, biomarkers, and the effect of azithromycin on eNO levels. Results In total, 172 participants were included in this sub-study, 86 from the placebo group and 86 from the azithromycin group. Participants experiencing at least one ARE during follow-up had significantly higher eNO levels at baseline than participants who did not (geometric mean ratio 1.13, 95% confidence interval [CI] 1.03–1.24, p = 0.015), adjusted for trial arm, age, sex and history of tuberculosis. Matrix metalloproteinase (MMP)-3, -7, and -10 were significantly associated with higher baseline eNO levels. At 48 weeks, azithromycin treatment did not affect eNO levels (geometric mean ratio 0.86, 95% CI 0.72–1.03, p = 0.103). Conclusion Higher baseline eNO levels were a risk factor for ARE. eNO was associated with proinflammatory biomarkers previously found to contribute to the development of chronic lung disease. The potential use of eNO as a marker of inflammation and risk factor for ARE in HIV-associated chronic lung disease needs further investigation

Optimizing Livelihood and Environmental Benefits from Crop Residues in Smallholder Crop-Livestock Systems in Southern Africa. Series Paper Number 11

Sustainable forms of intensification are needed to address the low and stagnant production of farming systems in southern Africa. More efficient use of crop-livestock interactions can contribute to this; in this context the effective use of crop residues is becoming increasingly important and also contested. Crop residues left on the field for mulching are expected to bring long-term environmental benefits but when fed to livestock they provide farmers with short-term livelihood benefits. This study aims at better understanding the diversity of farming systems and uses of crop residues, in particular the trade-offs in using the residues for soil amendment versus livestock feed. It is part of a global comparison with sites along a human and livestock population density gradient across sub-Saharan Africa and South Asia. This southern Africa study represents the most extensive case of semi-arid areas with lowest biomass production. Three sites were compared, at different levels of agricultural intensification, extent of crop-livestock integration and use of crop residues. 1. Mzimba in Northern Malawi – intensified crop oriented production. 2. Nkayi in southwest Zimbabwe – integrated crop-livestock systems. 3. Changara in Tete province in Central Mozambique – extensive crop-livestock farming. Across the three sites, crop residues are clearly needed as livestock feed. In Nkayi and Changara low crop yields and low biomass production against the existing demand from livestock prevents farmers from using residues for purposes other than livestock feed. The practice of collecting and kraal feeding residues in Nkayi illustrates that the pressure on residues is at a level where farmers start privatizing residues in order to ensure their individual benefits. When feeding crop residues in the kraal, farmers also increase the amount of manure for soil fertility improvement. Even in Mzimba, with higher residue production and lower livestock ownership, very few farmers retain the residues to achieve real impact on soil health. Although farmers see soil fertility as a critical constraint, they have limited residues to spare for mulching. The trade-offs of reallocating crop residues from livestock feed to mulching for soil amendment will be high as long as alternative feed technologies and access to input and output markets are not developed. The trade-offs will be lower in areas with higher biomass production and less competition with livestock. Technical options need to increase biomass on existing croplands, addressing feed shortages and the need for soil amendment concurrently. Viable institutional structures and appropriate policies need to support this intensification processes through better access to inputs, knowledge and markets. The pathways for sustainable intensification and more efficient crop residue utilization need to be developed within the local context. We found strong growth potential for livestock-oriented agricultural development in extensive areas (Changara), strengthening crop and livestock integration to support intensification in areas like Nkayi, and enhancing crop-livestock integration for more efficient resource utilization where biomass is less limiting (Mzimba)