Showing papers by "University of Zambia published in 2011"

Development of a standardized screening rule for tuberculosis in people living with HIV in resource-constrained settings: individual participant data meta-analysis of observational studies.

Abstract: Background: The World Health Organization recommends the screening of all people living with HIV for tuberculosis (TB) disease, followed by TB treatment, or isoniazid preventive therapy (IPT) when TB is excluded. However, the difficulty of reliably excluding TB disease has severely limited TB screening and IPT uptake in resource-limited settings. We conducted an individual participant data meta-analysis of primary studies, aiming to identify a sensitive TB screening rule. Methods and Findings: We identified 12 studies that had systematically collected sputum specimens regardless of signs or symptoms, at least one mycobacterial culture, clinical symptoms, and HIV and TB disease status. Bivariate random-effects meta-analysis and the hierarchical summary relative operating characteristic curves were used to evaluate the screening performance of all combinations of variables of interest. TB disease was diagnosed in 557 (5.8%) of 9,626 people living with HIV. The primary analysis included 8,148 people living with HIV who could be evaluated on five symptoms from nine of the 12 studies. The median age was 34 years. The best performing rule was the presence of any one of: current cough (any duration), fever, night sweats, or weight loss. The overall sensitivity of this rule was 78.9% (95% confidence interval [CI] 58.3%–90.9%) and specificity was 49.6% (95% CI 29.2%–70.1%). Its sensitivity increased to 90.1% (95% CI 76.3%–96.2%) among participants selected from clinical settings and to 88.0% (95% CI 76.1%–94.4%) among those who were not previously screened for TB. Negative predictive value was 97.7% (95% CI 97.4%–98.0%) and 90.0% (95% CI 88.6%–91.3%) at 5% and 20% prevalence of TB among people living with HIV, respectively. Abnormal chest radiographic findings increased the sensitivity of the rule by 11.7% (90.6% versus 78.9%) with a reduction of specificity by 10.7% (49.6% versus 38.9%). Conclusions: Absence of all of current cough, fever, night sweats, and weight loss can identify a subset of people living with HIV who have a very low probability of having TB disease. A simplified screening rule using any one of these symptoms can be used in resource-constrained settings to identify people living with HIV in need of further diagnostic assessment for TB. Use of this algorithm should result in earlier TB diagnosis and treatment, and should allow for substantial scale-up of IPT. Please see later in the article for the Editors’ Summary.

Smallholder Farmers’ Perceptions of Climate Change and Conservation Agriculture: Evidence from Zambia

Abstract: Actors involved in promoting conservation agriculture have often not taken into account perceptions of smallholder farmers of climate change and CA as an adaptation strategy. This study documents smallholder farmers’ perceptions of climate change and conservation agriculture. Most farmers attributed climate change to supernatural forces. Smallholder farmers’ perceptions related to floods and droughts were significantly associated with adoption of conservation agriculture. Extent to which smallholder farmers perceived conservation agriculture as a climate change adaptation strategy was very low. This suggests existence of other important reasons for practicing conservation agriculture than adaptation to climate change. Policy implications of the study are: conservation agriculture projects should not only focus on technical approaches to increase adoption rates but also consider social aspects such as perceptions that are equally important in conservation agriculture. Inclusion of climate change communication to facilitate exchange of climatic information that would enable smallholder farmers relate to conservation agriculture as an adaptation strategy is essential.

Net Benefits: A Multicountry Analysis of Observational Data Examining Associations between Insecticide- Treated Mosquito Nets and Health Outcomes

Abstract: Background: Several sub-Saharan African countries have rapidly scaled up the number of households that own insecticidetreated mosquito nets (ITNs). Although the efficacy of ITNs in trials has been shown, evidence on their impact under routine conditions is limited to a few countries and the extent to which the scale-up of ITNs has improved population health remains uncertain. Methods and Findings: We used matched logistic regression to assess the individual-level association between household ITN ownership or use in children under 5 years of age and the prevalence of parasitemia among children using six malaria indicator surveys (MIS) and one demographic and health survey. We used Cox proportional hazards models to assess the relationship between ITN household ownership and child mortality using 29 demographic and health surveys. The pooled relative reduction in parasitemia prevalence from random effects meta-analysis associated with household ownership of at least one ITN was 20% (95% confidence interval [CI] 3%–35%; I 2 = 73.5%, p,0.01 for I 2 value). Sleeping under an ITN was associated with a pooled relative reduction in parasitemia prevalence in children of 24% (95% CI 1%–42%; I 2 = 79.5%, p,0.001 for I 2 value). Ownership of at least one ITN was associated with a pooled relative reduction in mortality between 1 month and 5 years of age of 23% (95% CI 13–31%; I 2 = 25.6%, p.0.05 for I 2 value). Conclusions: Our findings across a number of sub-Saharan African countries were highly consistent with results from previous clinical trials. These findings suggest that the recent scale-up in ITN coverage has likely been accompanied by significant reductions in child mortality and that additional health gains could be achieved with further increases in ITN coverage in populations at risk of malaria. Please see later in the article for the Editors’ Summary.

Putting plant resistance traits on the map: a test of the idea that plants are better defended at lower latitudes

Abstract: • It has long been believed that plant species from the tropics have higher levels of traits associated with resistance to herbivores than do species from higher latitudes. A meta-analysis recently showed that the published literature does not support this theory. However, the idea has never been tested using data gathered with consistent methods from a wide range of latitudes. • We quantified the relationship between latitude and a broad range of chemical and physical traits across 301 species from 75 sites world-wide. • Six putative resistance traits, including tannins, the concentration of lipids (an indicator of oils, waxes and resins), and leaf toughness were greater in high-latitude species. Six traits, including cyanide production and the presence of spines, were unrelated to latitude. Only ash content (an indicator of inorganic substances such as calcium oxalates and phytoliths) and the properties of species with delayed greening were higher in the tropics. • Our results do not support the hypothesis that tropical plants have higher levels of resistance traits than do plants from higher latitudes. If anything, plants have higher resistance toward the poles. The greater resistance traits of high-latitude species might be explained by the greater cost of losing a given amount of leaf tissue in low-productivity environments.

Diarrhea is a Major killer of Children with Severe Acute Malnutrition Admitted to Inpatient Set-up in Lusaka, Zambia

Abstract: Introduction: Mortality of children with Severe Acute Malnutrition (SAM) in inpatient set-ups in sub-Saharan Africa still remains unacceptably high. We investigated the prevalence and effect of diarrhea and HIV infection on inpatient treatment outcome of children with complicated SAM receiving treatment in inpatient units. Method: A cohort of 430 children aged 6-59 months old with complicated SAM admitted to Zambia University Teaching Hospital’s stabilization centre from August to December 2009 were followed. Data on nutritional status, socio-demographic factors, and admission medical conditions were collected up on enrollment. T-test and chisquare tests were used to compare difference in mean or percentage values. Logistic regression was used to assess risk of mortality by admission characteristics. Results: Majority, 55.3% (238/430) were boys. The median age of the cohort was 17 months (inter-quartile range, IQR 12-22). Among the children, 68.9% (295/428) had edema at admission. The majority of the children, 67.3% (261/388), presented with diarrhea; 38.9% (162/420) tested HIV positive; and 40.5% (174/430) of the children died. The median Length of stay of the cohort was 9 days (IQR, 5-14 days); 30.6% (53/173) of the death occurred within 48 hours of admission. Children with diarrhea on admission had two and half times higher odds of mortality than those without diarrhea; Adjusted OR = 2.5 (95% CI 1.50-4.09, P < 0.001). The odds of mortality for children with HIV infection was higher than children without HIV infection; Adjusted OR = 1.6 (95% CI 0.99-2.48 P = 0.5). Conclusion: Diarrhea is a major cause of complication in children with severe acute malnutrition. Under the current standard management approach, diarrhea in children with SAM was found to increase their odds of death substantially irrespective of other factors.

Excellent adherence to antiretrovirals in HIV+ Zambian children is compromised by disrupted routine, HIV nondisclosure, and paradoxical income effects.

Abstract: Introduction A better understanding of pediatric antiretroviral therapy (ART) adherence in sub-Saharan Africa is necessary to develop interventions to sustain high levels of adherence. Methodology/Principal Findings Adherence among 96 HIV-infected Zambian children (median age 6, interquartile range [IQR] 2,9) initiating fixed-dose combination ART was measured prospectively (median 23 months; IQR 20,26) with caregiver report, clinic and unannounced home-based pill counts, and medication event monitoring systems (MEMS). HIV-1 RNA was determined at 48 weeks. Child and caregiver characteristics, socio-demographic status, and treatment-related factors were assessed as predictors of adherence. Median adherence was 97.4% (IQR 96.1,98.4%) by visual analog scale, 94.8% (IQR 86,100%) by caregiver-reported last missed dose, 96.9% (IQR 94.5,98.2%) by clinic pill count, 93.4% (IQR 90.2,96.7%) by unannounced home-based pill count, and 94.8% (IQR 87.8,97.7%) by MEMS. At 48 weeks, 72.6% of children had HIV-1 RNA <50 copies/ml. Agreement among adherence measures was poor; only MEMS was significantly associated with viral suppression (p = 0.013). Predictors of poor adherence included changing residence, school attendance, lack of HIV disclosure to children aged nine to 15 years, and increasing household income. Conclusions/Significance Adherence among children taking fixed-dose combination ART in sub-Saharan Africa is high and sustained over two years. However, certain groups are at risk for treatment failure, including children with disrupted routines, no knowledge of their HIV diagnosis among older children, and relatively high household income, possibly reflecting greater social support in the setting of greater poverty.

Advancing cervical cancer prevention initiatives in resource-constrained settings: insights from the Cervical Cancer Prevention Program in Zambia.

Abstract: Groesbeck Parham and colleagues describe their Cervical Cancer Prevention Program in Zambia, which has provided services to over 58,000 women over the past five years, and share lessons learned from the program's implementation and integration with existing HIV/AIDS programs.

Insecticide resistance and the future of malaria control in Zambia

Abstract: Background: In line with the Global trend to improve malaria control efforts a major campaign of insecticide treated net distribution was initiated in 1999 and indoor residual spraying with DDT or pyrethroids was reintroduced in 2000 in Zambia In 2006, these efforts were strengthened by the President’s Malaria Initiative This manuscript reports on the monitoring and evaluation of these activities and the potential impact of emerging insecticide resistance on disease transmission Methods: Mosquitoes were captured daily through a series of 108 window exit traps located at 18 sentinel sites Specimens were identified to species and analyzed for sporozoites Adult Anopheles mosquitoes were collected resting indoors and larva collected in breeding sites were reared to F1 and F0 generations in the lab and tested for insecticide resistance following the standard WHO susceptibility assay protocol Annual cross sectional household parasite surveys were carried out to monitor the impact of the control programme on prevalence of Plasmodium falciparum in children aged 1 to 14 years Results: A total of 619 Anopheles gambiae sl and 228 Anopheles funestus sl were captured from window exit traps throughout the period, of which 203 were An gambiae malaria vectors and 14 An funestus ss In 2010 resistance to DDT and the pyrethroids deltamethrin, lambda-cyhalothrin and permethrin was detected in both An gambiae ss and An funestus ss No sporozoites were detected in either species Prevalence of P falciparum in the sentinel sites remained below 10% throughout the study period Conclusion: Both An gambiae ss and An funestus ss were controlled effectively with the ITN and IRS programme in Zambia, maintaining a reduced disease transmission and burden However, the discovery of DDT and pyrethroid resistance in the country threatens the sustainability of the vector control programme

Social Responsibility as a Dimension of Intelligence, and as an Educational Goal: Insights From Programmatic Research in an African Society

Abstract: This article examines the implications that 4 decades of multimethod research in Zambia have for psy- chological assessment, parent-teacher communication, educational policy, and research methodology. Its pri- mary focus is a cultural study of indigenous ideas in a rural Chewa community in eastern Zambia that concluded that, within this culture, children's intelligence was con- strued as an amalgam of cognitive alacrity and social responsibility. But in Zambia, as elsewhere, the curricu- lum of institutionalized public basic schooling is almost exclusively addressed to the cultivation of knowledge and cognitive skills. The article outlines the approach to edu- cation taken by Child-to-Child, one that resonates with indigenous African values and practices. It also describes a case study of the application of this approach at a pub- lic primary school in northern Zambia that documented sustained increases in social responsibility alongside strong academic outcomes. Connections with research and policy in other societies are also discussed. KEYWORDS—social responsibility; intelligence; education; Africa; cultural psychology; socialization

Toward an Open-Access Global Database for Mapping, Control, and Surveillance of Neglected Tropical Diseases

Abstract: BACKGROUND: After many years of general neglect, interest has grown and efforts came under way for the mapping, control, surveillance, and eventual elimination of neglected tropical diseases (NTDs). Disease risk estimates are a key feature to target control interventions, and serve as a benchmark for monitoring and evaluation. What is currently missing is a georeferenced global database for NTDs providing open-access to the available survey data that is constantly updated and can be utilized by researchers and disease control managers to support other relevant stakeholders. We describe the steps taken toward the development of such a database that can be employed for spatial disease risk modeling and control of NTDs. METHODOLOGY: With an emphasis on schistosomiasis in Africa, we systematically searched the literature (peer-reviewed journals and 'grey literature'), contacted Ministries of Health and research institutions in schistosomiasis-endemic countries for location-specific prevalence data and survey details (e.g., study population, year of survey and diagnostic techniques). The data were extracted, georeferenced, and stored in a MySQL database with a web interface allowing free database access and data management. PRINCIPAL FINDINGS: At the beginning of 2011, our database contained more than 12,000 georeferenced schistosomiasis survey locations from 35 African countries available under http://www.gntd.org. Currently, the database is expanded to a global repository, including a host of other NTDs, e.g. soil-transmitted helminthiasis and leishmaniasis. CONCLUSIONS: An open-access, spatially explicit NTD database offers unique opportunities for disease risk modeling, targeting control interventions, disease monitoring, and surveillance. Moreover, it allows for detailed geostatistical analyses of disease distribution in space and time. With an initial focus on schistosomiasis in Africa, we demonstrate the proof-of-concept that the establishment and running on global NTD database is feasible and should be expanded without delay

Epidemiology of stillbirth in low-middle income countries: A Global Network Study

Abstract: OBJECTIVE: To determine population-based stillbirth rates and to determine whether the timing and maturity of the stillbirths suggest a high proportion of potentially preventable deaths. DESIGN: Prospective observational study. SETTING: Communities in six low-income countries (Democratic Republic of Congo Kenya Zambia Guatemala India and Pakistan) and one site in a mid-income country (Argentina). POPULATION: Pregnant women residing in the study communities. METHODS: Over a five-year period in selected catchment areas using multiple methodologies trained study staff obtained pregnancy outcomes on each delivery in their area. MAIN OUTCOME MEASURES: Pregnancy outcome stillbirth characteristics. RESULTS: Outcomes of 195400 deliveries were included. Stillbirth rates ranged from 32 per 1000 in Pakistan to 8 per 1000 births in Argentina. Three-fourths (76%) of stillbirth offspring were not macerated 63% were >/= 37 weeks and 48% weighed 2500 g or more. Across all sites women with no education of high and low parity of older age and without access to antenatal care were at significantly greater risk for stillbirth (p /= 37 weeks gestation and almost half weighed at least 2500 g. With access to better medical care especially in the intrapartum period many of these stillbirths could likely be prevented. (c) 2011 Nordic Federation of Societies of Obstetrics and Gynecology No claim to original US government works.

High prevalence of drug resistance in animal trypanosomes without a history of drug exposure.

Abstract: Background: Trypanosomosis caused by Trypanosoma congolense is a major constraint to animal health in sub-Saharan Africa. Unfortunately, the treatment of the disease is impaired by the spread of drug resistance. Resistance to diminazene aceturate (DA) in T. congolense is linked to a mutation modifying the functioning of a P2-type purine-transporter responsible for the uptake of the drug. Our objective was to verify if the mutation was linked or not to drug pressure. Methodology/Principal Findings: Thirty-four T. congolense isolates sampled from tsetse or wildlife were screened for the DA-resistance linked mutation using DpnII-PCR-RFLP. The results showed 1 sensitive, 12 resistant and 21 mixed DpnII-PCRRFLP profiles. This suggests that the mutation is present on at least one allele of each of the 33 isolates. For twelve of the isolates, a standard screening method in mice was used by (i) microscopic examination, (ii) trypanosome-specific 18S-PCR after 2 months of observation and (iii) weekly trypanosome-specific 18S-PCR for 8 weeks. The results showed that all mice remained microscopically trypanosome-positive after treatment with 5 mg/kg DA. With 10 and 20 mg/kg, 8.3% (n=72) and 0% (n=72) of the mice became parasitologically positive after treatment. However, in these latter groups the trypanosomespecific 18S-PCR indicated a higher degree of trypanosome-positivity, i.e., with a unique test, 51.4% (n=72) and 38.9% (n=72) and with the weekly tests 79.2% (n=24) and 66.7% (n=24) for 10 and 20 mg/kg respectively. Conclusion/Significance: The widespread presence of the DA-resistance linked mutation in T. congolense isolated from wildlife suggests that this mutation is favourable to parasite survival and/or its dissemination in the host population independent from the presence of drug. After treatment with DA, those T. congolense isolates cause persisting low parasitaemias even after complete elimination of the drug and with little impact on the host’s health.

The human resource for health situation in Zambia: deficit and maldistribution

Abstract: Introduction Current health policy directions in Zambia are formulated in the National Health Strategic Plan. The Plan focuses on national health priorities, which include the human resources (HR) crisis. In this paper we describe the way the HRH establishment is distributed in the different provinces of Zambia, with a view to assess the dimension of shortages and of imbalances in the distribution of health workers by province and by level of care.

Options for Improving Smallholder Conservation Agriculture in Zambia

Abstract: This study examined the agronomic practices of smallholder Conservation Agriculture (CA) farmers in Zambia. Questionnaire survey, focus group discussions, key informant interviews, field assessments, desk study and soil analyses were employed to collect data on tillage systems, crop rotations, weed control, soil fertility management, crop residue retention and crop yields. The results showed that weed management, crop residue retention, timely planting and soil fertility management were the most challenging for CA farmers especially those without reliable access to oxen. Crop residue retention conflicted with the socio-cultural practices of the communities and was hardly practised while crop rotation seemed difficult in light of the dominance of maize cultivation and the lack of markets for crop legumes. Possible options for improving smallholder CA systems were greater integration of livestock, correct herbicide application, market provision for crop legumes, farmer training in agri-business and better access to agricultural credit and subsidized inputs. CA promoters must incorporate the farmers’ local cultural contexts in order to better address the challenges associated with adopting CA.

Seroprevalence of brucellosis and its associated risk factors in cattle from smallholder dairy farms in Zimbabwe

Abstract: A cross-sectional study was conducted to investigate seroprevalence of brucellosis and the associated risk factors in cattle from smallholder dairy farms in Gokwe, Marirangwe, Mushagashe, Nharira, Rusitu and Wedza areas of Zimbabwe. A total of 1,440 cattle from 203 herds were tested serially for Brucella antibodies using Rose Bengal test and the competitive ELISA. Weighted seroprevalence estimates were calculated and risk factors in individual cattle investigated using logistic regression analysis. The overall individual animal brucellosis seroprevalence was low, with mean of 5.6% (95% confidence interval (CI), 4.4%, 6.8%). Gokwe had the highest individual (12.6%; 95% CI, 3.9%, 21.4%) and herd-level (40.0%; 95% CI, 22.1%, 58.0%), while Wedza had the lowest individual (2.3%; 95% CI, 0%, 5.3%) and herd-level (8.0%; 95% CI, 0.0%, 18.9%) brucellosis seroprevalence, respectively. In individual cattle, the area of origin, age and history of abortion were independently associated with brucellosis seroprevalence. While the seroprevalence was independent of sex, it decreased with increasing age. Cattle 2–4 years old had higher odds (odds ratio (OR) = 3.2; 95% CI, 1.1%, 9.1%) of being seropositive compared to those >7 years. Cows with a history of abortion were more likely to be seropositive (OR = 7.9; 95% CI, 3.1, 20.1) than controls. In conclusion, the area-to-area variation of brucellosis may be linked to ecological factors and differences in management practices. The implementation of stamping out policy, bleeding and testing animals before movement and promoting the use self-contained units are likely to significantly reduce the public health risks associated with Brucella infections in cattle.

Early Weaning Increases Diarrhea Morbidity and Mortality Among Uninfected Children Born to HIV-infected Mothers in Zambia

Abstract: Background. Early weaning may reduce human immunodeficiency virus (HIV) transmission but may have deleterious consequences for uninfected children. Here we evaluate effects of early weaning on diarrhea morbidity and mortality of uninfected children born to HIV-infected mothers. Methods. HIV-infected women in Lusaka, Zambia, were randomly assigned to breastfeeding for 4 months only or to continue breastfeeding until the mother decided to stop. Replacement and complementary foods were provided and all women were counseled around feeding and hygiene. Diarrhea morbidity and mortality were assessed in 618 HIV-uninfected singletons alive and still breastfeeding at 4 months. Intent-to-treat analyses and comparisons based on actual feeding practices were conducted using regression methods. Results. Between 4 and 6 months, diarrheal episodes were 1.8-fold (95% confidence interval (CI), 1.3‐2.4) higher in the short compared with long breastfeeding group. Associations were stronger based on actual feeding practices and persisted after adjustment for confounding. At older ages, only more severe outcomes, including diarrhea-related hospitalization or death (relative hazard [RH], 3.2, 95% CI, 2.1‐5.1 increase 4‐24 months), were increased among weaned children. Conclusions. Continued breastfeeding is associated with reduced risk of diarrhea-related morbidity and mortality among uninfected children born to HIV-infected mothers in this low-resource setting despite provision of replacement and complementary food and counseling. Clinical Trials Registration. NCT00310726.

A worldwide analysis of beta-defensin copy number variation suggests recent selection of a high-expressing DEFB103 gene copy in East Asia.

Abstract: Beta-defensins are a family of multifunctional genes with roles in defense against pathogens, reproduction, and pigmentation. In humans, six beta-defensin genes are clustered in a repeated region which is copy-number variable (CNV) as a block, with a diploid copy number between 1 and 12. The role in host defense makes the evolutionary history of this CNV particularly interesting, because morbidity due to infectious disease is likely to have been an important selective force in human evolution, and to have varied between geographical locations. Here, we show CNV of the beta-defensin region in chimpanzees, and identify a beta-defensin block in the human lineage that contains rapidly evolving noncoding regulatory sequences. We also show that variation at one of these rapidly evolving sequences affects expression levels and cytokine responsiveness of DEFB103, a key inhibitor of influenza virus fusion at the cell surface. A worldwide analysis of beta-defensin CNV in 67 populations shows an unusually high frequency of high-DEFB103-expressing copies in East Asia, the geographical origin of historical and modern influenza epidemics, possibly as a result of selection for increased resistance to influenza in this region. Hum Mutat 32:743–750, 2011. © 2011 Wiley-Liss, Inc.

The Association between Household Socioeconomic Position and Prevalent Tuberculosis in Zambia: A Case-Control Study

Abstract: ALTHOUGH HISTORICALLY TUBERCULOSIS (TB) HAS BEEN ASSOCIATED WITH POVERTY, FEW ANALYTICAL STUDIES FROM DEVELOPING COUNTRIES HAVE TRIED TO: 1. assess the relative impact of poverty on TB after the emergence of HIV; 2. explore the causal mechanism underlying this association; and 3. estimate how many cases of TB could be prevented by improving household socioeconomic position (SEP).

Prevalence of hypertension and its correlates in Lusaka urban district of Zambia: a population based survey

Abstract: Background Hypertension is a leading cause for ill-health, premature mortality and disability. The objective of the study was to determine the prevalence and associated factors for hypertension in Lusaka, Zambia.

Isolation of non-tuberculous mycobacteria from pastoral ecosystems of Uganda: Public Health significance

Abstract: Background: The importance of non-tuberculous mycobacteria (NTM) infections in humans and animals in subSaharan Africa at the human-environment-livestock-wildlife interface has recently received increased attention. NTM are environmental opportunistic pathogens of humans and animals. Recent studies in pastoral ecosystems of Uganda detected NTM in humans with cervical lymphadenitis and cattle with lesions compatible with bovine tuberculosis. However, little is known about the source of these mycobacteria in Uganda. The aim of this study was to isolate and identify NTM in the environment of pastoral communities in Uganda, as well as assess the potential risk factors and the public health significance of NTM in these ecosystems. Method: A total of 310 samples (soil, water and faecal from cattle and pigs) were examined for mycobacteria. Isolates were identified by the INNO-Lipa test and by 16S rDNA sequencing. Additionally, a questionnaire survey involving 231 pastoralists was conducted during sample collection. Data were analysed using descriptive statistics followed by a multivariable logistic regression analysis. Results: Forty-eight isolates of NTM were detected; 25.3% of soil samples, 11.8% of water and 9.1% from animal faecal samples contained mycobacteria. Soils around water sources were the most contaminated with NTM (29.8%). Of these samples, M. fortuitum-peregrinum complex, M. avium complex, M. gordonae, and M. nonchromogenicum were the most frequently detected mycobacteria. Drinking untreated compared to treated water (OR = 33), use of valley dam versus stream water for drinking and other domestic use (OR = 20), sharing of water sources with wild primates compared to antelopes (OR = 4.6), sharing of water sources with domestic animals (OR = 5.3), and close contact with cattle or other domestic animals (OR = 13.8) were the most plausible risk factors for humans to come in contact with NTM in the environment. Conclusions: The study detected a wide range of potentially pathogenic NTM from the environment around the pastoral communities in Uganda. Drinking untreated water and living in close contact with cattle or other domestic animals may be risk factors associated with the possibility of humans and animals acquiring NTM infections from these ecosystems. Background Although members of the Mycobacterium tuberculosis complex (MTC) are responsible for the majority of mycobacterial infections worldwide, environmental opportunistic infections due to non-tuberculous

Climate change/variability implications on hydroelectricity generation in the Zambezi River Basin

Abstract: The study has analysed the effects of various factors on hydroelectric power generation potential to include climate change/variability, water demand, and installation of proposed hydroelectric power schemes in the Zambezi River Basin. An assessment of historical (1970–2000) power potential in relation to climate change/variability at existing hydro electric power schemes(Cahora Bassa, Kariba, Kafue Gorge and Itezhi-Tezhi) in the Zambezi River Basin was conducted. The correlation of hydroelectric power potential with climate change/variability aimed at observing the link and extent of influence of the latter on the former was investigated. In order to predict the future outlook of hydro electric power potential, General Circulation Models (GCM) were used to generate projected precipitation. The monthly simulated precipitation was extracted from the GCM for every sub basin and used to compute future precipitation. Further, future water demand in the sub basins of the Zambezi River Basin were estimated based on the respective population growth rate in each sub basin. Subsequently, water balance model, with projected precipitation and water demand input was used to determine projected run-offs of sub basins of the Zambezi River Basin. .Based on the projected run-offs of sub basins, reservoir storage capacities at existing hydro electric power schemes were estimated. The baseline assessment revealed a strong relationship between hydroelectric power potential and climate change/variability. The study also revealed that the main climate and other risks associated with current and future hydro electric power generation include projected dry years, floods and increasing water demand. The results indicate that the hydroelectric power potential has a tendency towards gradual reduction in its potential in all existing and proposed hydroelectric power schemes owing to climate change and increasing water demand.

Uptake of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead-zinc mine in Kabwe, Zambia.

Abstract: Concentrations of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead-zinc mine in Kabwe (Zambia), which is ranked among the 10 worst polluted places on earth, were compared with other Zambian towns. Metal concentrations were measured in the liver and kidneys of 51 cattle from Kabwe and other Zambian towns. The maximum metal concentrations, expressed in mg/kg and dry weight, in the liver or kidneys were 398.4 (Cu), 252.6 (Zn), 77.81 (Cr), 19.37 (Cd), 7.57 (Ni), 1.8 (Pb), 1.04 (Co), 0.112 (Hg), and 0.05 (As). Concentrations of Pb and Cd in Kabwe cattle were higher than levels in other Zambian towns. The mean concentration of Cd exceeded benchmark values in offal destined for human consumption. Levels of Ni and Cr may also pose public health concerns. Concentrations of Pb and Cr, Pb and Cu, Cd and Zn, Cd and Hg, Zn and Cu, Cu and Co, as well as Co and Ni were positively correlated. The present study also highlighted the dangers of exposure of animals and humans to a mixture of toxic metals.

Phylogenetic Relationships of Asclepias (Apocynaceae) Inferred from Non-Coding Chloroplast DNA Sequences

Abstract: Milkweeds ( Asclepias s. l., Apocynaceae) are characteristic perennial herbs of grasslands in North America and Africa that have long served as models for studying the evolutionary ecology of plant reproduction and plant defense. Generic circumscription of Asclepias has been long debated with recent workers favoring delimitation on geographic grounds; Asclepias s. s. is limited to the Americas and only seg- regate genera are recognized for African species. A widely used system introduced by Woodson classifies North American Asclepias into nine subgenera, with the largest subgenus, Asclepias , further divided into eight series. We investigated the phylogeny of Asclepias using three non- coding loci from the plastid genome: rpl16 intron, trnC GCA -rpoB spacer, and the adjacent trnS GCU -trnG UUC spacer and trnG UUC intron. Parsimony, likelihood, and Bayesian analyses were conducted to evaluate hypotheses of continental and taxonomic monophyly. Hypothesis tests were conducted under the parsimony and likelihood criteria. We found moderate support for the monophyly of American Asclepias s. s. and for all but one representative of African Asclepias s. l. Within the Amerian clade, South American species are strongly supported as monophyletic and derived from North American ancestors. Only one of Woodson's 17 infrageneric taxa was found to be monophyletic. Monophyly of more than one half of the remaining 16 taxa could be statistically rejected using a conservative a level. Our results are consistent with taxonomic restric- tion of Asclepias to American species and single colonization events from Africa to North America and North America to South America. They also point to a need for major restructuring of infrageneric classification and future revsionary work.

Attitudes of primary health care providers towards people with mental illness: evidence from two districts in Zambia

Abstract: Objective: The aim of this study was to explore health care providers’ attitudes towards people with mental illness within two districts in Zambia. It sought to document types of attitudes of primary health care providers towards people suffering from mental illness and possible predictors of such attitudes. This study offers insights into how health care providers regard people with mental illness that may be helpful in designing appropriate training or re-training programs in Zambia and other low-income African countries. Method: Using a pilot tested structured questionnaire, data were collected from a total of 111 respondents from health facilities in the two purposively selected districts in Zambia that the Ministry of Health has earmarked as pilot districts for integrating mental health into primary health care. Results: There are widespread stigmatizing and discriminatory attitudes among primary health care providers toward mental illness and those who suffer from it. These findings confirm and add weight to the results from the few other studies which have been conducted in Africa that have challenged the notion that stigma and discrimination of mental illness is less severe in African countries. Conclusion: There is an urgent need to start developing more effective awareness-raising, training and education programmes amongst health care providers. This will only be possible if there is increased consensus, commitment and political will within government to place mental health on the national agenda and secure funding for the sector. These steps are essential if the country is improve the recognition, diagnosis and treatment of mental disorders, and realize the ideals enshrined in the progressive health reforms undertaken over the last decade.

Seasonal prevalence and incidence of Cryptosporidium spp. and Giardia duodenalis and associated diarrhoea in children attending pre-school in Kafue, Zambia

Abstract: Prevalence, incidence and seasonal variation of Cryptosporidium and Giardia duodenalis were studied over a 12-month period in 100 children from four pre-schools in Kafue, Zambia. Questionnaire data and a single stool sample were collected monthly from each child. Samples were processed using a commercial kit (Meridian Diagnostics Inc., USA) and oo(cysts) visualised by immunofluorescence microscopy. Cryptosporidium was detected in 30.7% (241/786; 95% CI = 27.5-33.9) while G. duodenalis was detected in 29.0% (228/786; 95% CI = 25.8-32.2). A total of 86% experienced one or more episodes of cryptosporidiosis while 75% had giardiasis. Cumulative incidence per 100 children was 75.4 for Cryptosporidium and 49.0 for G. duodenalis. Both infections were significantly more common in the wet compared to the dry season (34.8%, 162/466 vs. 24.7%, 79/320, P = 0.003 and 35.2%, 164/466 vs. 20.0%, 64/320, P < 0.001, respectively). Thus, risk ratios (RR) were 1.41 (95% CI = 1.13-1.77) and 1.76 (95% CI = 1.38-2.27) for Cryptosporidium and Giardia, respectively. Diarrhoea was significantly associated with cryptosporidiosis (RR = 1.23, 95% CI = 1.03-1.47; P = 0.029) but not with giardiasis (RR = 1.12, 95% CI = 0.91-1.53; P = 0.26). We conclude that gastro-intestinal protozoal infections are highly prevalent among children attending pre-school in peri-urban Zambia highlighting the need for further studies of risk factors.

Assessing the microbiological performance and potential cost of boiling drinking water in urban Zambia.

Abstract: Boiling is the most common method of disinfecting water in the home and the benchmark against which other point-of-use water treatment is measured. In a six-week study in peri-urban Zambia, we assessed the microbiological effectiveness and potential cost of boiling among 49 households without a water connection who reported "always" or "almost always" boiling their water before drinking it. Source and household drinking water samples were compared weekly for thermotolerant coliforms (TTC), an indicator of fecal contamination. Demographics, costs, and other information were collected through surveys and structured observations. Drinking water samples taken at the household (geometric mean 7.2 TTC/100 mL, 95% CI, 5.4-9.7) were actually worse in microbiological quality than source water (geometric mean 4.0 TTC/100 mL, 95% CI, 3.1-5.1) (p < 0.001), although both are relatively low levels of contamination. Only 60% of drinking water samples were reported to have actually been boiled at the time of collection from the home, suggesting over-reporting and inconsistent compliance. However, these samples were of no higher microbiological quality. Evidence suggests that water quality deteriorated after boiling due to lack of residual protection and unsafe storage and handling. The potential cost of fuel or electricity for boiling was estimated at 5% and 7% of income, respectively. In this setting where microbiological water quality was relatively good at the source, safe-storage practices that minimize recontamination may be more effective in managing the risk of disease from drinking water at a fraction of the cost of boiling.