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Institution

University of Zambia

EducationLusaka, Lusaka, 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.


Papers
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Journal ArticleDOI
TL;DR: The southern Irumide belt (SIB) is an ENE-WSW-trending, late Mesoproterozoic orogenic belt located between the Congo-Tanzania-Bangweulu (CTB) and Kalahari cratons in central southern Africa.
Abstract: The southern Irumide Belt (SIB) is an ENE^WSW-trending, late Mesoproterozoic orogenic belt located between the Congo^Tanzania^ Bangweulu (CTB) and Kalahari cratons in central southern Africa. It is separated from the late Mesoproterozoic Irumide Belt (IB) to the north by Permo-Triassic graben, raising the possibility that the younger rifts reactivated a suture between the two belts that has been rendered cryptic as a result of younger Karoo cover. Both belts are dominated by calc-alkaline gneisses, but in addition the SIB contains abundant metavolcanic and metasedimentary rocks. In this study we present detailed geochemical, isotopic and geochronological data for volcanic and plutonic lithologies from the southernmost part of the SIB, the Chewore^Rufunsa Terrane. This terrane comprises a wide variety of supracrustal to mid-crustal rocks that have major- and trace-element compositions similar to magmas formed in present-day subduction zones. Chondrite-normalized rare earth element (REE) profiles and whole-rock Sm^Nd isotope compositions indicate that the parental supra-subduction melts interacted with, and were contaminated by sialic continental crust, implying a continental-margin-arc setting. Secondary ionization mass spectrometry dating of magmatic zircon has yielded crystallization ages between c. 1095 and 1040 Ma, similar to elsewhere in the SIB. U^Pb dating and in situ Lu^Hf isotopic analyses of abundant xenocrystic zircon extracted from the late Mesoproterozoic granitoids indicate that the contaminant continental basement was principally Palaeoproterozoic in age and had a juvenile isotopic signature at the time of its formation. These data are in contrast to those for the IB, which is characterized by younger, c. 1020 Ma, calc-alkaline gneisses that formed by the direct recycling of Archaean crust without significant addition of any juvenile material. We suggest that the SIB developed by the subduction of oceanic crust under the margin of an unnamed continental mass until ocean closure at c. 1040 Ma. Subsequent collision between the SIB and the CTB margin led to the cessation of magmatism in the SIB and the initiation of compression and crustal melting in the IB.

42 citations

Journal ArticleDOI
TL;DR: Evidence of heterogeneity of the infection risk was found at the micro-geographical level and a sound understanding of small-scale heterogeneity, caused by spatial aggregation of schoolchildren, is important to inform health planners for implementing control schistosomiasis interventions.
Abstract: In line with the aims of the "National Bilharzia Control Programme" and the "School Health and Nutrition Programme" in Zambia, a study on urinary schistosomiasis was conducted in 20 primary schools of Lusaka province to further our understanding of the epidemiology of the infection, and to enhance spatial targeting of control. We investigated risk factors associated with urinary schistosomiasis, and examined small-scale spatial heterogeneity in prevalence, using data collected from 1,912 schoolchildren, 6 to 15-year-old, recruited from 20 schools in Kafue and Luangwa districts. The risk factors identified included geographical location, altitude, normalized difference vegetation index (NDVI), maximum temperature, age, sex of the child and intermediate host snail abundance. Three logistic regression models were fitted assuming different random effects to allow for spatial structuring. The mean prevalence rate was 9.6%, with significance difference between young and older children (odds ratio (OR) = 0.71; 95% confidence interval (CI) = 0.51-0.96). The risk of infection was related to intermediate host snail abundance (OR = 1.03; 95% CI = 1.00-1.05) and vegetation cover (OR = 1.04; 95% CI = 1.00-1.07). Schools located either on the plateau and the valley also differed in prevalence and intensity of infection for moderate infection to none (OR = 1.64; 95% CI = 1.36- 1.96). The overall predictive performance of the spatial random effects model was higher than the ordinary logistic regression. In addition, evidence of heterogeneity of the infection risk was found at the micro-geographical level. A sound understanding of small-scale heterogeneity, caused by spatial aggregation of schoolchildren, is important to inform health planners for implementing control schistosomiasis interventions.

42 citations

Journal ArticleDOI
TL;DR: Viewing an HIVST demonstration video did not improve participant understanding of self-test usage procedures compared to an instructional sheet alone, but it increased confidence in the ability to self- test, especially among those not accessing existing HIV testing services.
Abstract: We assessed attitudes and preferences toward HIV self-testing (HIVST) among Zambian adolescents and adults. We conducted a population-based survey of individuals aged 16-49 years old in Lusaka Province, Zambia. HIVST was shown to participants through a short video on oral fluid-based self-testing. In addition to demographics, HIV risk perceptions, and HIV testing history, we assessed participants' acceptability and concerns regarding HIVST. Using a discrete choice experiment, we investigated preferences for the location of self-test pickup, availability of counseling, and cost. After reviewing an instructional sheet or an additional video, we assessed participants' understanding of self-test performance. Among 1617 participants, 647 (40.0%) were male, 269 (16.6%) were adolescents and 754 (46.6%) were nontesters (i.e., no HIV test in the past 12 months). After viewing the video, 1392 (86.0%) reported that HIVST would make them more likely to test and while 35.0% reported some concerns with HIVST, only 2% had serious concerns. Participants strongly preferred HIVST over finger prick testing as well as having counseling and reported willingness to pay out-of-pocket (US$3.5 for testers and US$5.5 for nontesters). Viewing an HIVST demonstration video did not improve participant understanding of self-test usage procedures compared to an instructional sheet alone, but it increased confidence in the ability to self-test. In conclusion, HIVST was highly acceptable and desirable, especially among those not accessing existing HIV testing services. Participants expressed a strong preference for counseling and a willingness to pay for test kits. These data can guide piloting and scaling-up of HIVST in Zambia and elsewhere in Africa.

42 citations

Journal ArticleDOI
TL;DR: The high biomass P concentration and longer growing season in 1991/92 season were exceptional and may have been related to reduced competition by shallow rooting herbaceous plants caused by the severe drought of that season.
Abstract: Seasonality in nitrogen (N) and phosphorus (P) concentration in soil and shoots of five Brachystegia-Julbernardia (miombo) woodland trees was studied from September 1991 to March 1993 at two regrowth miombo sites in central Zambia. Shoot growth started in the dry season (September–November) and lasted until April during the 1991/92 season but had virtually ceased by January 1993 during the 1992/93 season. The shoot growing season was associated with low foliar N/P ratios. These ratios were much lower (<5) during the 1991/92 season than in the 1992/93 season (12–15). The increase in foliar N/P ratios after the shoot growing season was caused by a sharp drop in foliar P concentration, apparently due to reabsorption before leaf fall. There were no annual variations in biomass N concentration in contrast to P. During the 1992/93 growing season P concentrations in foliage and wood were a quarter and a third, respectively, of the 1991/ 92 levels. Since the short shoot growing season observed during the 1992/93 season is typical of savanna woodland trees in southern Africa, the high biomass P concentration and longer growing season in 1991/92 season were exceptional and may have been related to reduced competition by shallow rooting herbaceous plants caused by the severe drought of that season.

42 citations

Journal ArticleDOI
TL;DR: This is a substudy of a larger randomized controlled trial on HIV-infected Zambian children, which revealed that cotrimoxazole prophylaxis reduced morbidity and mortality despite a background of high cotinoxazol resistance.
Abstract: This is a substudy of a larger randomized controlled trial on HIV-infected Zambian children, which revealed that cotrimoxazole prophylaxis reduced morbidity and mortality despite a background of high cotrimoxazole resistance. The impact of cotrimoxazole on the carriage and antibiotic resistance of Streptococcus pneumoniae and Haemophilus influenzae as major causes of childhood mortality in HIV-infected children was investigated since these are unclear. Representative nasopharyngeal swabs were taken prior to randomization for 181 of 534 children (92 on cotrimoxazole and 89 on placebo). Bacterial identification and antibiotic susceptibility were performed by routine methods. Due to reduced mortality, prophylactic cotrimoxazole increased the median time from randomization to the last specimen from 48 to 56 months (P = 0.001). The carriage of H. influenzae was unaltered by cotrimoxazole. Carriage of S. pneumoniae increased slightly in both arms but was not statistically significant in the placebo arm. In S. pneumoniae switching between carriage and no carriage in consecutive pairs of samples was unaffected by cotrimoxazole (P = 0.18) with a suggestion that the probability of remaining carriage free was lower (P = 0.10). In H. influenzae cotrimoxazole decreased switching from carriage to no carriage (P = 0.02). Cotrimoxazole resistance levels were higher in postbaseline samples in the cotrimoxazole arm than in the placebo arm (S. pneumoniae, P < 0.0001; H. influenzae, P = 0.005). Cotrimoxazole decreased switching from cotrimoxazole resistance to cotrimoxazole sensitivity in S. pneumoniae (P = 0.002) and reduced the chance of H. influenzae remaining cotrimoxazole sensitive (P = 0.05). No associations were observed between the percentage of CD4 (CD4%), the change in CD4% from baseline, child age at date of specimen, child gender, or sampling month with carriage of either pathogen.

42 citations


Authors

Showing all 2635 results

NameH-indexPapersCitations
Alimuddin Zumla10074743284
David Clark7365224857
Sten H. Vermund6960622181
Paul A. Kelly6820816836
Francis Drobniewski6729317371
Ayato Takada6727314467
Karl Peltzer6088018515
Hirofumi Sawa5532511735
Peter Godfrey-Faussett521738486
Igor J. Koralnik5219710186
Peter Mwaba481327386
Alison M. Elliott482997772
Kelly Chibale473377713
Chihiro Sugimoto473257737
Sian Floyd471636791
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202318
202248
2021481
2020505
2019358
2018299