University of Zambia

About: University of Zambia is a education organization based out in Lusaka, Lusaka, Zambia. It is known for research contribution in the topics: Population & Health care. The organization has 2593 authors who have published 4402 publications receiving 122411 citations. The organization is also known as: UNZA.

The geochronological framework of the irumide belt: A prolonged crustal history along the margin of the Bangweulu Craton

Abstract: Ion microprobe U-Th-Pb analyses of zircon from 40 granitoid rocks collected from the late Mesoproterozoic Irumide Belt in Central Southern Africa, along the southern margin of the Archean to Paleoproterozoic Bangweulu Block, provide a comprehensive set of age data for this complex orogen. The data indicate that the Irumide Belt is constructed on a basement of principally Paleoproterozoic (ca. 2.05-1.93 Ga) age with a subordinate Neoarchean (ca. 2.73 Ga) component, which is overlain by a platformal quartzite-pelite succession known as the Muva Supergroup. Previously published U-Pb detrital zircon data for the Paleoproterozoic Muva Super- group, which show age populations that match all of the pre-1.9 Ga basement components identified within the Irumide Belt, suggest that the pre-Muva basement was assembled as a coherent block by 1.8 Ga, which we refer to as the Bangweulu Craton. The southern margin of the Bangweulu Craton was then intruded by a previously unrecognized suite of biotite-bearing granitoid rocks between 1.66 and 1.55 Ga, not recorded elsewhere in the region, and was later the site of emplacement of voluminous granitoid magmatism during the Irumide Orogeny at between 1.05 and 1.00 Ga. Hf isotopic data from zircon in these suites indicate variable influence from cryptic Archean rocks in the lower crustal melting zone of the Bangweulu Block. U-Pb analyses of inherited zircon cores in magmatic zircon in these granitoid rocks, directly confirm the presence of this reworked cryptic Archean basement of the Bangweulu Craton. The age data confirm previously proposed tectonic models for the Mesoprot- erozoic evolution of central Africa, refuting the presence of a continent-spanning Grenvillian-aged Orogen, including the Kibaran Belt, Irumide Belt and Choma- Kalomo Block of central Africa and connecting with Mesoproterozoic terranes further south along the margins of the Kalahari Craton. The data clearly show that the Proterozoic tectonic evolution of the Bangweulu Craton, which became attached to the southern margin of the larger Congo Craton during the Mesoproterozoic, involved a series of distinct convergent orogenic episodes affecting and reworking its southern (passive) margin. The mismatch in timing of Mesoproterozoic orogenic activity along the Bangweulu Craton, compared to that on the margins of the Kalahari, is compatible with the notion that these continental fragments were not juxtaposed along these Mesoproterozoic belts and in their present-day relative positions at the time. Whether either of these central and southern African cratons did form part of Rodinia, however, remains a matter for debate.

Measuring health workers' motivation in rural health facilities: baseline results from three study districts in Zambia

Abstract: Introduction: Health worker motivation can potentially affect the provision of health services. Low morale among the workforce can undermine the quality of service provision and drive workers away from the profession. While the presence of high-quality, motivated staff is a key aspect of health system performance, it is also one of the most difficult factors to measure. Methods: We assessed health worker motivation as part of the baseline assessment for a health system strengthening intervention in three rural districts in Zambia. The intervention (Better Health Outcomes Through Mentoring and Assessment (BHOMA)) aims to increase health worker motivation through training, mentoring and support. We assessed motivation by examining underlying issues grouped around relevant outcome constructs such as job satisfaction, general motivation, burnout, organization commitment, conscientiousness and timeliness that collectively measure overall levels of motivation. The tools and the concepts have been used in high-income countries and they were recently applied in African settings to measure health worker motivation. Results: Female participants had the highest motivation scores (female: mean 78.5 (SD 7.8) vs male: mean (SD 7.0)). By type of worker, nurses had the highest scores while environmental health technicians had the lowest score (77.4 (SD 7.8 vs 73.2 (SD 9.3)). Health workers who had been in post longer also had higher scores (>7 months). Health workers who had received some form of training in the preceding 12 months were more likely to have a higher score; this was also true for those older than 40 years when compared to those less than 40 years of age. The highest score values were noted in conscientiousness and timeliness, with all districts scoring above 80. Conclusions: This study evaluated motivation among rural health workers using a simple adapted tool to measure the concept of motivation. Results showed variation in motivation score by sex, type of health worker, training and time in post. Further research is needed to establish why these health worker attributes were associated with motivation and whether health system interventions targeting health workers, such as the current intervention, could influence health worker motivation.

Characterization of the Envelope Glycoprotein of a Novel Filovirus, Lloviu Virus

Abstract: Lloviu virus (LLOV), a novel filovirus detected in bats, is phylogenetically distinct from viruses in the genera Ebolavirus and Marburgvirus in the family Filoviridae. While filoviruses are known to cause severe hemorrhagic fever in humans and/or nonhuman primates, LLOV is biologically uncharacterized, since infectious LLOV has never been isolated. To examine the properties of LLOV, we characterized its envelope glycoprotein (GP), which likely plays a key role in viral tropism and pathogenicity. We first found that LLOV GP principally has the same primary structure as the other filovirus GPs. Similar to the other filoviruses, virus-like particles (VLPs) produced by transient expression of LLOV GP, matrix protein, and nucleoprotein in 293T cells had densely arrayed GP spikes on a filamentous particle. Mouse antiserum to LLOV VLP was barely cross-reactive to viruses of the other genera, indicating that LLOV is serologically distinct from the other known filoviruses. For functional study of LLOV GP, we utilized a vesicular stomatitis virus (VSV) pseudotype system and found that LLOV GP requires low endosomal pH and cathepsin L, and that human C-type lectins act as attachment factors for LLOV entry into cells. Interestingly, LLOV GP-pseudotyped VSV infected particular bat cell lines more efficiently than viruses bearing other filovirus GPs. These results suggest that LLOV GP mediates cellular entry in a manner similar to that of the other filoviruses while showing preferential tropism for some bat cells.

Condom and nonoxynol-9 use and the incidence of HIV infection in serodiscordant couples in Zambia.

Abstract: We aimed to measure the effectiveness of latex condoms and of nonoxynol-9 [N-9] spermicides, in preventing HIV transmission in heterosexual serodiscordant couples in Lusaka. Each couple was examined at clinic visits scheduled at 3-month intervals for one year or more per couple, or until seroconversion or discontinuation. Couples were given condoms and their choice of 3 N-9 products and advised to use both at every intercourse. Sexual exposure was ascertained from coital logs that recorded coitus and barrier method use. HIV serological testing was done at each clinic visit (ELISA and Western blot if positive). One hundred and ten discordant couples were followed for a mean of 17.6 months. Seventy-eight per cent of coital episodes were protected by condoms, 85% by spermicides and 6.4% were unprotected. Fourteen seroconversions occurred (8.7 infections per 100 couple-years [c-y]). The rate was higher among seronegative men than seronegative women. Among couples who reported using condoms at every intercourse the infection rate was 2.3/100 c-y, compared with 10.7/100 c-y among couples using condoms less consistently (rate ratio [RR] 0.2; 95% confidence interval [CI] 0-1.6). Among couples who reported using N-9 at every intercourse, the seroconversion rate was 6.9/100 c-y; among couples who reported less than full-time N-9 use, the rate was 8.9/100 c-y (RR 0.8; 95% CI 0.2-2.8). Among the subset of female seronegatives, the N-9 RR was 0.5 (95% CI 0.1-3.8). But when we calculated HIV rates according to N-9 consistency in coital acts when condoms were not used, there was no evidence of protection with higher N-9 use. Consistent use of latex condoms reduces the incidence of HIV infection, but the association between N-9 spermicides and HIV is less clear. The current study could not provide compelling data on the impact of N-9 spermicide use on risk of HIV infection. The study's small size, as well as the consistency of concurrent condom use, limited our inferences. Available spermicide products must be studied further.

Prevalence and distribution of gastrointestinal helminths and their effects on weight gain in free-range chickens in Central Zambia

Abstract: Examination of helminths from gastrointestinal tracts of 125 free-range chickens in Zambia revealed a 95.2% prevalence rate. The species and their prevalences were: Allodapa suctoria (85.6%), Tetrameres americana (80.8%), Ascaridia galli (28.8%), Gonglonema ingluvicola (50.4%), Raillietina spp. (81.6%) and Heterakis gallinarum (32.8%). No trematodes or Syngamus trachea were found. Mixed infections accounted for 88.2% as compared to 7.2% of single infections. Effects of helminthoses on weight gain were investigated in 100 growing chickens randomly assigned to treatment (levamisole) and untreated control groups. There was a significant mean (±SEM) weight gain (grams) of 812.8 ± 51.4 in the treatment group and 623 ± 57.4 in the control group (p < 0.01). The mean (±SEM) worm burdens from the control group and the treatment group were 96.3 ± 5.61 and 22.05 ± 2.61, respectively. These results confirm the higher risk of helminth infections in free-range systems and may explain the deleterious effects in chickens.