Showing papers by "University of Zambia published in 2001"

Socio‐economic, gender and health services factors affecting diagnostic delay for tuberculosis patients in urban Zambia

Abstract: In-depth interviews regarding health seeking behaviour were conducted with 202 adults registered with pulmonary tuberculosis at the centralized Chest Clinic in Lusaka, Zambia. The median (mean) diagnostic delay was 8.6 (9) weeks, and was significantly associated with the following factors: female sex, lower education, more than six instances of health-seeking encounters, outpatient diagnosis of tuberculosis, and visiting a private doctor or traditional healer. More effective tuberculosis control interventions require novel methods of accessing women and less educated people. Decentralization of public tuberculosis care and improved integration with private sector health providers may also reduce diagnostic delay.

Integrated assessment of catchment suspended sediment budgets: a Zambian example

Abstract: In many developing countries, the management of sediment-related environmental problems is severely hampered by a lack of information on sediment mobilization and delivery in river basins. The sediment budget concept represents a valuable framework for assembling such information, which can, in turn, be used to assist with the design and implementation of soil erosion and sediment control policies. However, the information necessary to construct a catchment sediment budget is difficult to assemble. Against this background, an integrated approach to establishing a catchment suspended sediment budget, involving a river monitoring station, the use of 137Cs measurements to estimate soil erosion and deposition and floodplain accumulation rates within the catchment, and sediment source fingerprinting, has been developed and tested in the 63 km2 catchment of the upper Kaleya River in southern Zambia. The approach developed not only provides detailed information on individual components of the suspended sediment delivery system, but also permits the establishment of the overall catchment sediment budget. A sediment budget for the upper Kaleya catchment is presented and both its key features and its wider implications for catchment management are discussed. Copyright © 2001 John Wiley & Sons, Ltd.

Vertical transmission of Kaposi's sarcoma‐associated herpesvirus

Abstract: Little is presently known about the specific routes of transmission of Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus-8 (HHV-8). To investigate whether this agent might be transmitted vertically from mother to infant, we conducted a study on 89 KSHV seropositive mothers and their newborn infants. Thirteen mothers (14.6%) had KSHV DNA detected in their peripheral blood mononuclear cells (PBMC). Two of 89 samples drawn at birth from infants born to KSHV seropositive mothers had KSHV DNA detectable within their PBMC. These findings suggest that KSHV can be transmitted perinatally, but infrequently. Other routes of transmission such as horizontal transmission remain the most likely means of KSHV transmission.

Education as a vehicle for combating HIV/AIDS

Abstract: We want to depart from academic tradition by concluding with a direct appeal to our readers. We implore everyone who reads these words and who is in a position of authority to do two things: first, to become better informed about HIV/AIDS and its actual and potential effects on education, and second, from this stand-point to provide informed, committed leadership that encourages the actions and provides the resources required for managing and controlling this devastating pandemic.

Performance of Zambian children on the NEPSY: a pilot study.

Abstract: Forty-five literate schoolchildren aged 9 (n = 25) and 11 (n = 20) from urban Zambia were given core and expanded tests on the NEPSY and their performance was scored according to age-equivalent norms for U.S. children. This study indicates that in urban, literate Zambian children, the NEPSY is relatively insensitive to language and cultural influences that often compromise the applicability of Western tests in the developing world. No consistent improvement in the standard scores was found as a function of educational experience. Comparison against the U.S. normative average revealed that both age groups were poorer in the domains of language and attention and executive functions, whereas their performance was better in the visuospatial processing domain. It is concluded that the NEPSY in its present form may be clinically useful, but its results should still be treated with caution, taking into account cultural, language, and personal demographic information. More studies, with divergent and larger samples of varying age ranges are required. It seems that the NEPSY could serve as the initial step in the development of neuropsychological practices in Zambia.

A conceptual framework for the economic analysis of factors influencing decision-making of small-scale farmers in animal health management.

Abstract: The delivery of veterinary services in most of sub-Saharan Africa has undergone substantial changes, with the private sector gaining increasing recognition as an alternative to state provision. Given this policy shift, the authors argue that a better understanding of the behaviour and decision-making processes of small-scale farmers in animal health management is urgently required, to guide policy decisions regarding the delivery of animal health services. Whether the involvement of the private sector will improve overall efficiency in the delivery of veterinary services will depend greatly on the demand response of livestock producers who must make decisions about the health of livestock. The authors briefly review the decision-making process in small-scale farming systems, the economic nature of animal diseases and disease control and the models that have been used to guide resource allocation for disease control. To gain an improved understanding of the behaviour and decision-making processes of small-scale farmers, the authors propose a conceptual model including variables that relate to characteristics specific to small-scale farmers and farms, economic factors, institutional setting and biophysical factors. Two possible approaches are proposed for the economic analysis. Agricultural household modelling allows the derivation and testing of hypotheses regarding the demand elasticities for veterinary services, while qualitative choice models are better suited to the analysis of determinants behind the choices of farmers. The authors conclude that an urgent need exists for empirical research in this area.

Helicobacter pylori Infection in an Urban African Population

Abstract: We have studied 221 adults drawn from an impoverished urban population with high human immunodeficiency virus (HIV) seroprevalence (35%) to determine the prevalence of gastroduodenal pathology and its relationship to serological markers of Helicobacter pylori virulence proteins and other potential environmental and immunological determinants of disease including HIV infection. Eighty-one percent were H. pylori seropositive, and 35% were HIV seropositive. Urban upbringing and low CD4 count were associated with a reduced likelihood of H. pylori seropositivity, as was current Ascaris infection, in keeping with recent evidence from an animal model. One hundred ninety-one adults underwent gastroduodenoscopy, and 14 had gastroduodenal pathology. Mucosal lesions were a major cause of abdominal pain in this population. While the majority of patients with gastroduodenal pathology (12 of 14) were seropositive for H. pylori, none were seropositive for HIV. Smoking was associated with increased risk of macroscopic pathology, and a history of Mycobacterium bovis BCG immunization was associated with reduced risk. Antibodies to H. pylori lipopolysaccharide were associated with pathology. HIV infection was associated with protection against mucosal lesions, suggesting that fully functional CD4 lymphocytes may be required for the genesis of gastroduodenal pathology.

Sexual behaviour and sexually transmitted diseases among young men in Zambia.

Abstract: Sexually transmitted diseases (STDs) are an increasing public health problem in Zambia. About 200 000 cases of STDs are treated annually in the formal health sector. Young people are the most affected by STDs. High-risk sexual behaviour has been identified as the major risk factor for STDs among young people. We conducted interviews and focus group discussions with a purposely selected sample of 126 young men aged between 16 and 26 in Chiawa, rural Zambia. The aim of the interviews and focus group discussions was to explore views about sexual practices and attitudes towards STD. Fifty-eight (59%) young men reported having had pre-marital or extra-marital sexual partners during the past year. The maximum number was five partners for six individuals. Forty-two (43%) had pre-marital or extra-marital sexual partners at the time of the interviews. Focus group discussions revealed that perceptions of manhood encouraged multiple sexual relationships. Twenty-two (23%) reported having suffered from an STD in the past. Seventy-nine (81%) said they were likely to inform their sexual partners if they had an STD. Although condoms were believed to give protection against STDs by the majority (94%), only 6% said they always used condoms. The data suggest that condoms were perceived to affect male potency. These results show that STDs, multiple sexual relationships and unprotected sex are common among the young men of Chiawa. Perceptions that emphasize manhood are widespread and these may negatively affect efforts for positive behavioural change. Health messages that target the young men should take into account the local perceptions and values that seem to sustain risky sexual behaviour.

Simulation of the mixed-mode natural-convection solar drying of maize

Abstract: A mathematical model for mixed mode natural convection solar drying of maize grain is presented. The drying is described by a deep bed procedure that includes conduction within the grain bed. The conduction is due to radiative energy falling on the upper surface of the bed. The results show that temperatures at the top and bottom of the bed are higher than that in the middle resulting in two drying fronts one at the top and the other at the bottom of the bed and moving in opposite directions. This results in more uniform moisture content distribution than in an indirect dryer. The results are verified against experimental data from a prototype mixed mode natural convection maize solar dryer. The laboratory solar dryer was constructed at Newcastle University, U.K. and the experiments carried out under a solar simulator. The agreement between theory and experiment is very good.

Drug-resistant tuberculosis in Africa.

Abstract: Africa has the highest incidence rate per capita of tuberculosis, although the rate varies among the African countries from 17.8% in Cameroon to 70% in Botswana, Zambia, and Zimbabwe. Nevertheless, the levels of drug resistance are relatively low, compared to countries like Russia and Estonia. Because treatment of MDR TB is beyond the reach of most African countries, prevention of the development of resistance should be a major priority. Establishment of programs to ensure prompt diagnosis of TB and adequate treatment with supervision should be undertaken by national governments with cooperating partners.

Genetic effects and heterosis of flowering and fruit characteristics of tropical pumpkin

Abstract: Tropical pumpkin is an important vegetable in many lowland tropics. Estimation of genetic effects for a fixed set of genotypes may yield information on the presence of different types of gene action for important traits. Six landraces and one diallel set of their progeny were evaluated for time from planting to female anthesis and fruit characteristics. Variety effects and heterosis mean squares were significant for the days to female anthesis, the weight of the first mature fruit, the mean fruit weight and soluble solids, indicating the presence of both additive and non-additive gene actions. Only variety effects were significant for the days to the first mature fruit. These characters could be improved by recurrent selection. Selection for heterosis would be effective except for the days to the first fruit to mature.

Traditional healers in Zambia and their care for patients with urethral/vaginal discharge.

Abstract: Objective: The aim of this study was to describe the knowledge and practices of traditional healers in relation to the management of patients with urethral/vaginal discharge. Subjects and method: Eighty (80) traditional healers, 54 from an urban and 26 from a rural setting in Zambia, who attend to patients with urethral/vaginal discharge, were interviewed using a semistructured questionnaire. Result: All of the traditional healers had knowledge of urethral/vaginal discharge being a symptom of a sexually transmitted disease (STD) and that individuals get the infection through sexual relations with infected persons. The healers were all able to cite other symptoms associated with urethral/vaginal discharge. The treatment the healers used was mostly herbal preparations in the form of roots or powders administered orally to induce diarrhea, vomiting, and diuresis. Patients were not allowed to combine traditional and biomedical therapies. Almost half of the healers did apply some biomedical practices in the ma...

An investigation of heavy metal exposure and risks to wildlife in the Kafue flats of Zambia.

Abstract: Exposure and ecological risks to heavy metals (copper, zinc, manganese, iron) at Lochnivar and Blue Lagoon National Parks in wildlife dependent on the Kafue river contaminated with mining waste was evaluated. Samples included water, fish, grasses and Kafue Lechwe (Kobus leche kafuensis) liver. At both parks copper ranged from 0.03-0.04 mg/l; 3.0-6.0 mg/kg; 11.0-44.0 mg/kg; trace -199.0 mg/kg; while zinc was 0.01 mg/l; 32.0-82.0 mg/kg; 15.0-21.0 mg/kg; and 52.0-138.0 mg/kg; in water, fish, grasses and lechwe, respectively. Manganese ranges were 0.15-0.16 mg/l; 7.0-18.0 mg/kg; 51.0-145.0 mg/kg; and 40.0-53.0 mg/kg while iron ranges were 0.13-0.14 mg/l; 26.0-134.0 mg/kg; 1766.0-1797.0 mg/kg; and131.0-856.0 mg/kg; in water, fish, grasses and lechwe, respectively. Levels in all samples except water were high indicating potential for adverse effects.

Colonial Legacy and the Role of Society in the Creation and Demise of Autocracy in Zambia, 1964-1991

Abstract: This paper explores the origin, growth and demise of autocracy in post-independence Zambia from a macro-historical perspective. It is argued that the underlying dynamic, which gradually turned Zambia into a virtual autocracy after its independence in 1964, stems from its colonial past, although augmented by the Zambians themselves. It is shown how emerging heroworship within the dominant United National Independence Party (UNIP) turned the country’s first president, with the support of the people, into an autocrat. In the 1980’s the autocracy started to seriously crumble in the face of food riots and rising unemployment resulting from a deepening economic depression. It is concluded that, despite the return to a multi-party state in 1991, there are strong indications that this newly found democracy is already being undermined by the same dynamic that led to autocracy in the first place. [Ed.]

A survey on anthelmintic resistance in nematode parasites of sheep in Lusaka, Zambia.

Abstract: While surveys in Southern Africa indicate anthelmintic resistance of gastrointestinal nematodes to be common in small ruminants in South Africa, Kenya and Zimbabwe there have been no reports of resistance in Zambia. The objective of this study was to determine whether anthelmintic resistance occurs in Zambia, and to obtain information on nematode control practices in the country. During the rainy season six commercial sheep farms were selected in and around Lusaka and Chisamba. Worm control practices were gauged by means of a questionnaire, and the Faecal Egg Count Reduction Test was performed for assessing anthelmintic efficacy of albendazole, levamisole and ivermectin. On all farms anthelmintic treatment was the only approach used to control nematode infections. Frequency of treatment varied from twice a year to every 6 weeks and drugs of different anthelmintic groups were alternated within the same year. There was a wide range in faecal egg counts of individual sheep before treatment, with some individual counts of up to 87000. Larval identification showed that Haemonchus was almost the only genus recovered from the faecal cultures before and after treatment. Albendazole resistance was found on five of the six farms. On each of the four farms where ivermectin gave less than 95 % reduction in egg counts, there was resistance to albendazole as well. Levamisole showed an efficacy of 95 % or higher on all six farms.

AIDS-related knowledge, attitudes and behavior among urban youths in Zambia Results from a pilot study

Abstract: In this article we report the results of a pilot study conducted among in-school and out-of-school youths in Lusaka the capital of Zambia in February 1997. Specifically we describe the adolescents AIDS-related knowledge attitudes and behavior. Studies in the West indicate that adolescents who have dropped out of school (e.g. homeless delinquents those who are in residential centers) are more likely to be at risk of HIV infection because of their tendency to engage in AIDS-related high-risk activities (DiClemente 1991; Nader et al. 1989; Rotheram-Borus et al. 199la; Slonim-Nevo et al. 1996). In order to examine whether a similar situation is occurring in Zambia we included participants who had dropped out of school and were learning a technical profession (e.g. sewing and carpentry) in the community. The method of this pilot study is described in the Appendix. (excerpt)

Impaired bioavailability of vitamin A in adults and children with persistent diarrhoea in Zambia.

Abstract: Background: We have previously demonstrated a strong relationship between low serum retinol concentration and mortality in Zambian AIDS patients with diarrhoea, but were unable to detect any benefit from oral micronutrient supplementation. Aim: To test the hypothesis that this is related to impaired availability of vitamin A, we analysed serum retinol concentration changes over 6 h following oral mega-dose therapy (60, 120 or 180 mg retinol). Methods: Twenty-four men without diarrhoea, 15 adults with persistent diarrhoea and 11 children (six girls, five boys) with persistent diarrhoea were studied. Results: Men with persistent diarrhoea had lower baseline serum retinol concentrations (median 0.39 μmol/L, interquartile range 0.21–0.56) than controls (median 1.16 μmol/L, interquartile range 0.84–1.47; P=0.0003). After 60 mg retinol, the rise in serum retinol in HIV seropositive controls (median 0.63 μmol/L, interquartile range 0.35–0.77) did not differ significantly from that observed in HIV seronegative controls (median 0.35 μmol/L, interquartile range – 0.04–0.56; P=0.20). Increasing the dose to 120 mg or 180 mg retinol did not enhance the increase in serum retinol concentration. The increase in serum retinol was less in adults with persistent diarrhoea (median 0.25 μmol/L, interquartile range 0.04–0.35) and in children (median 0.11 μmol/L, interquartile range 0.04–0.46) than in men without diarrhoea (median 0.44 μmol/L, interquartile range 0.26–0.74; P=0.03). Adults and children with diarrhoea had greater losses of retinol in urine over a 24-h period than controls, but less than 1% of the ingested dose was excreted. Conclusions: These results suggest that persistent diarrhoea in this population is associated with reduced bioavailability of retinol. Further work is required to determine the metabolic fate of therapeutic doses of retinol and to determine appropriate replacement strategies for HIV infected individuals.

Incidence and severity of frogeye leaf spot and associated yield losses in soybeans in agroecological zone II of Zambia.

Abstract: The incidence and severity of frogeye leaf spot of soybean (Glycine max (L.) Merr.) was studied in agroecological region II of Zambia during the 1997/98 crop growing season. A survey was conducted on farmers' fields on SCSI Kaleya, Magoye and Hernon-147 cultivars. Disease incidence and severity was assessed by monitoring disease increments at two weeks interval (beginning of January to April) from nine fields, three from each province. Soybean cultivars were evaluated for yield losses resulting from frogeye leaf spot. Field plots of each cultivar were either sprayed twice with benomyl (benlate) or not sprayed at all. The results showed that the incidence of frogeye leaf spot was highest in Southern province (5.1), followed by Lusaka province (4.9) while Central province had the lowest disease incidence (1.8). Values for area under disease progress curve (AUDPC) were significantly greater (P < 0.05) for Lusaka and Southern provinces than for Central province. Yields in benomyl protected plots ranged from 1444 kg ha−1 to 2320 kg ha−1 and were significantly different among the cultivars. Average yields of non protected plants were reduced by 30.5% for Kaleya, 35.6% for Hernon-147 and 37.2% for SCS1. Incidence and severity increased with time and varied depending on weather parameters and susceptibility of cultivars to the disease. Yield losses due to frogeye leaf spot occurred through a reduction in seed size. Differences in weather conditions and amount of inocula are believed to contribute to the observed variation in incidence and severity of the disease at different locations.

Lack of evidence for small intestinal mucosal T-cell activation as a pathogenic mechanism in African HIV-associated enteropathy.

Abstract: The role of mucosal T-cell activation in HIV-associated enteropathy is uncertain. Twenty Zambian patients with AIDS and chronic diarrhea were studied, as were nine controls. Distal duodenal biopsies were taken at endoscopy. Morphometric analysis and dual color immunofluorescence staining were performed. Villous height was reduced [177 (118-228) vs 305 (244-358) microm P = 0.002] and crypt depth increased [220 (164-202) vs 194 (164-202) microm P = 0.008] in AIDS patients compared to controls. CD3+CD4+ T cells were reduced in AIDS patients compared to controls [12.9 (5.7-25.2) vs 47.6 (33.4-65.5)% P = 0.04]. There was no significant difference in expression of CD8, CD25, CD69, HML-1, or HLA-DR on T cells between the AIDS patients and controls, with the exception of CD3+HML-1+ cells, which were increased in AIDS patients (P = 0.05). Small intestinal T-cell activation was similar between AIDS patients and controls. We conclude, therefore, that this mechanism is not likely to be important in the pathogenesis of HIV-associated enteropathy.

Development of the Regional Policy Process for Air Pollution in South Asia, Southern Africa and Latin America

Abstract: Projections indicate that large increases in emissions may occur in developing countries during the next twenty to fifty years if current development patterns persist. This paper describes the development of co-operation regarding air pollution issues in three sub-regions of three continents. Experiences gained through activities within a programme on Regional Air Pollution in Developing Countries are used to illustrate progress. The sub-regional process in South Asia developed through a series of meetings that led to the Male Declaration. In southern Africa a policy dialogue led to the Harare Resolution targeted towards progress in the SADC region. A policy dialogue in Buenos Aires concentrated on issues related to regional harmonisation of legal frameworks in the Mercosur region. In all regions the link between scientific information required to support decision making has been emphasised. The sub-regional policy processes are analysed in relation to availability of required scientific information and compared to the process that led to protocol development in Europe.

Length‐based Beverton and Holt spawning stock biomass per‐recruit‐models, with application to the Lates stappersii (Boulenger) stock in Lake Tanganyika

Abstract: Two kinds of length-based Beverton and Holt spawning stock biomass per-recruit (SSB/R)-models are presented. The first allows the computation of the absolute value of SSB/R. The second estimates the index of SSB/R, also called ‘relative SSB/R’. Both models are extensions of the original age-based Beverton and Holt SSB/R-models. The SSB/R and its index can be assessed with reference to variations in the exploitation characteristics. These models were applied to the Lates stappersii (Boulenger) stock in Lake Tanganyika using fishing mortality as the independent variable. They produce an absolute value of SSB/R of 12.95 g, representing 22.4% of that of the ‘virgin’ stock for the 1993–1994 equilibrium-fishing regime. This level is indicative of an unsafe state of the stock in question. Moreover, the SSB for L. stappersii seems to be fragile under increased fishing pressure as, for example, doubling or tripling the current fishing regime would reduce the current SSB/R by 57.3 and 77.4%, respectively. In general, the use of length-based Beverton and Holt SSB/R-models is handicapped by underlying hypotheses and sub-models which are restrictive.