Showing papers by "University of Zimbabwe published in 1994"

Vitamin B12 deficiency is the primary cause of megaloblastic anaemia in Zimbabwe

Abstract: Summary. In a study of the pathogenesis and clinical features of megaloblastic anaemia in southern Africa, we evaluated 144 consecutive Zimbabwean patients with megaloblastic haemopoiesis. Vitamin B12 deficiency was diagnosed in 86.1% of patients and was usually due to pernicious anaemia; isolated folate deficiency accounted for only 5/5% of cases. Anaemia was present in 95.8% of patients; the haemoglobin (Hb) was 6 g/dl in 63.9%. Neurological dysfunction was noted in 70.2% of vitamin B12-deficient patients and was most striking in those with Hb values > 6 g/dl. Serum levels of methylmalonic acid, homocysteine, or both, were increased in 98.5% of patients. Vitamin B12 deficiency is the primary cause of megaloblastic anaemia in Zimbabwe and, contrary to textbook statements, is often due to pernicious anaemia. Isolated folate deficiency is less common. As reported in industrialized countries 75 years ago, anaemia is almost always present and often severe. Neurological dysfunction due to vitamin B12 deficiency is most prominent in patients with mild to moderate anaemia.

Randomised controlled trial of intrapartum fetal heart rate monitoring.

Abstract: Objective : To compare effectiveness of different methods of monitoring intrapartum fetal heart rate. Design : Prospective randomised controlled trial. Setting : Referral maternity hospital, Harare,Zimbabwe. Subjects : 1255 women who were 37 weeks or more pregnant with singleton cephalic presentation and normal fetal heart rate before entry into study. Interventions : Intermittent monitoring of fetal heart rate by electronic monitoring, Doppler ultrasound, use of Pinard stethoscope by a research midwife, or routine use of Pinard stethoscope by attending midwife. Main outcome measures - Abnormal fetal heart rate patterns, need for operative delivery for fetal distress, neonatal mortality, Apgar scores, admission to neonatal unit, neonatal seizures, and hypoxic ischaemic encephalopathy. Results : Abnormalities in fetal heart rate were detected in 54% (172/318) of the electronic monitoring group, 32% (100/312) of the ultrasonography group, 15% (47/310) of the Pinard stethoscope group, and 9% (28/315) of the routine monitoring group. Caesarean sections were performed for 28% (89), 24% (76), 10% (32), and 15% (46) of the four groups respectively. Neonatal outcome was best in the ultrasonography group: hypoxic ischaemic encephalopathy occurred in two, one, seven, and 10 cases in the four groups respectively; neonatal seizures occurred only in the last two groups (six and nine cases respectively); and deaths occurred in eight,two, five, and nine cases respectively. Conclusions : Abnormalities in fetal heart rate were more reliably detected by Doppler ultrasonography than with Pinard stethoscope, and its use resulted in good perinatal outcome. The use ofrelatively cheap ultrasound monitors should be further evaluated and promoted in obstetric units caring for high risk pregnancies in developing countries with scarce resources.

Diseases and Management of Backyard Chicken Flocks in Chitungwiza, Zimbabwe

Abstract: To gather information on backyard chicken flocks in Chitungwiza, an urban center in Zimbabwe, 85 flock owners were interviewed. The mean flock size was 53 birds (range 1-650), and most birds were kept for meat, for either domestic consumption or local sale. Mean age at slaughter was 12.4 weeks (range 8-24). None of the owners vaccinated their birds, and reported mortality rates were high (mean 25%), most commonly being associated with diseases causing eye and respiratory problems. Most owners complained of a lack of technical and veterinary advice. Commercial enzyme-linked immunosorbent assays on sera from 460 birds in 52 flocks showed that the birds had been exposed to avian reovirus (3%), avian leukosis virus (9%), avian encephalomyelitis virus (11%), Newcastle disease virus (27%), Mycoplasma gallisepticum and M. synoviae (33%), Pasteurella multocida (52%), infectious bursal disease virus (55%), reticuloendotheliosis virus (65%), and infectious bronchitis virus (86%). Parasite infections were detected only rarely.

Exploring the Self-Concept in an African Culture

Abstract: Self-concept orientations (individualistic, collectivistic, and moralistic) were examined for 210 Zimbabwe college students of a Shona cultural background. Although the students tended to endorse an individualistic self-concept orientation to a significant extent, the women and the older students were more inclined to perceive of the self-concept as collectivistic and moralistic in orientation. Implications for self-concept models for African cultures and suggestions for further research are discussed.

The influence of trees on soil fertility on two contrasting semi-arid soil types at Matopos, Zimbabwe

Abstract: An investigation into the influence of indigenous trees on soil fertility was conducted in an area of semi-arid tropical savanna in Zimbabwe on two contrasting soil types: dystrophic savanna soils (sandy soils) and eutrophic savanna soils (fine-textured soils). The study adds further support to the growing literature showing that trees have a positive influence on soil fertility. The study suggests that tree clearance, as advocated in these agropastoral systems, may not necessarily result in long-term benefits. It is argued that the primary mechanism by which soil fertility is improved is through increased litter and soil organic matter compartments under trees. The influence of trees on cation levels is greater on sandy soils than fine-textured soils because the exchange capacity of fine-textured soils is determined largely by soil texture whereas organic matter is the prime determinant of exchange capacity in sandy soils. The present study demonstrates that fertility improvement under trees is not at the expense of fertility decline in the surface soils of the zone around the tree. Leaf quality, as reflected simply in leaf C:N ratio, influences decomposition rates but the activities of termites probably confound any simple relationship. Litter quality of tree species is probably important in determining levels of soil organic matter under canopies, with higher levels under species with lower leaf quality.

A serosurvey using enzyme-linked immunosorbent assay for antibodies against poultry pathogens in ostriches (Struthio camelus) from Zimbabwe.

Abstract: Horseradish peroxidase-conjugated goat anti-ostrich IgG was raised and used in commercial enzyme-linked immunosorbent assay kits to detect antibodies reactive with 11 poultry pathogens in sera from 149 ostriches from nine farms around Zimbabwe. Antibodies were detected to turkey rhinotracheitis virus (99%), Newcastle disease virus (23%), avian reovirus (19%), infectious bursal disease virus (15%), avian encephalomyelitis virus (15%), Mycoplasma gallisepticum and/or M. synoviae (11%), reticuloendotheliosis virus (10%), Salmonella enteritidis (8%), avian leukosis virus (3%), infectious bronchitis virus (2%), and Pasteurella multocida (< 1%). Although evidence of prior infection with turkey rhinotracheitis and newcastle disease virus was present on all farms tested, there was marked variation between farms in the prevalence of exposure to other poultry pathogens.

A new pathogenic spotted fever group rickettsia from Africa.

Abstract: A spotted fever group (SFG) rickettsia was isolated in Zimbabwe from a patient with tick-bite, fever, headache and regional lymphadenopathy. A further six isolates were obtained from Amblyomma hebraeum ticks collected in Zimbabwe. These human and tick isolates were indistinguishable from each other, and from an Ethiopian SFG rickettsia, by microimmunofluorescence (MIF), sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting and polymerase chain reaction followed by restriction fragment length polymorphism analysis (PCR-RFLP). They were, however, distinguishable from other SFG ricketsiae by MIF serotyping and in the case of the most closely related serotypes, Rickettsia conorii and the Israeli SFG rickettsia, by SDS-PAGE and Western blot. PCR-RFLP failed to distinguish between the Zimbabwean and Israeli SFG rickettsia, though each of these gave different digestion products from R. conorii. The Zimbabwean human and tick isolates and the Ethiopian SFG rickettsiae therefore represent a previously undescribed rickettsial serotype which apparently is pathogenic in human beings. It is proposed that the new serotype be named the agent of African tick-bite fever in order to distinguish it from R. conorii, which until now has been recognized as the only SFG rickettsia to infect man in Africa.

Preliminary findings on the effect of load-carrying to the structural integrity of the cervical spine

Abstract: Carrying loads on the head is a common practice in rural Zimbabwe. Headloading imposes a considerable amount of strain to the axial skeleton. The cervical spine, being the most cranial and mobile part of the vertebral column, may be susceptible to spondylosis or disc degeneration in headloading. Age as well as the effects of intrinsic factors on cervical spondylosis have been well documented. However, studies on the effect of extrinsic weight bearing to spondylosis on the cervical spine are lacking. In this study, the effect of headloading on the pattern of spondylosis attributed to aging was examined. Results indicated that age led to significant degeneration of the fifth intervertebral disc space (P<0.05) as well as significant straightening of the lordotic curve (P<0.01). Load carrying seems to accentuate the straightening of the curve (P<0.001). The results also suggest that headloading creates a shift in the degeneration from the fifth intervertebral disc space to higher levels. It is concluded that carrying heavy loads on the head alters the pattern of degenerative changes of the cervical spine.

Sexual behaviour and HIV knowledge among adolescent boys in Zimbabwe

Abstract: A study on sexual behaviour and knowledge of HIV risk was undertaken amongst 511 male students in Zimbabwe. The study was conducted amongst pupils aged 11 to 19 years drawn from urban and rural secondary schools using a self-administered questionnaire. Thirty seven pc of the students reported that they had experienced sexual intercourse, with up to 63 pc reporting having had more than one partner. Twenty one pc of boys aged 12 years reported having had intercourse and the proportion increased with age. Knowledge about AIDS was high (93 pc) with up to 75 pc of the boys reporting that they received the information through the media and only 31 pc got it from their teachers. Logistic regression used to analyse reasons for variation in HIV/AIDS knowledge and of modes of its transmission determined that educational level, actual school attended, access to information from magazines and educational aspirations were significant predictors (p values = 0,005) of knowledge. Individual risk assessment was higher amongst students who reported sexual experience (p = 0,0001). Sixty pc of the sexually experienced boys reported having used condoms. Six pc of the boys reported having intercourse with a commercial sex worker and of these, 85 pc used condoms. Compared with previous studies there appeared to be a reduction in high risk behaviours amongst male secondary school students. However, there is need for increased HIV preventive information through school educational programmes, as increase and variation in HIV information and modes of transmission was seen depending on access to information.

Serologic evidence for human ehrlichiosis in Africa

Abstract: Human ehrlichiosis is a recently recognized rickettsial disease. It is caused byEhrlichia chaffeensis, an intraleucocytic Gram-negative, obligate intracellular bacterium, grouped within the genusEhrlichiae. Most human cases of ehrlichiosis have been diagnosed in the USA. Two cases have been reported outside of the USA, one in Europe and one in Africa. From 1 January to 30 June 1992, 765 sera from blood donors or other asymptomatic subjects in 8 African countries, including Ivory Coast, Burkina Faso, Mali, Central African Republic, Angola, Zimbabwe, Mozambique and Commores Islands, were tested by indirect immunofluorescence for the presence ofE. chaffeensis antibodies. Positive sera were confirmed by Western immunoblotting. Only two of 765 sera tested were positive. One serum obtained from Burkina Faso had an IgG titer of 1:200 and one from Mozambique had an IgG titer of 1:80. Human ehrlichiosis seems to occur infrequently in Africa, although many more sera from additional African countries need to be evaluated.

Snake poisoning in rural Zimbabwe : a prospective study

Abstract: Over a period of 2 years (January 1991 to December 1992) 274 cases of snake bite were admitted to hospital in the eight provinces of Zimbabwe. Of these patients, 54% were males and 88% belonged to the 6-40-year age group. Five deaths (1.8% of the total cases) were reported. The majority of snake bites (63%) occurred at night (between 6.30 p.m. and midnight) and over 74% took place during the hot rainy season, i.e. between November and April. In over 58% of the cases the victim accidentally stepped on the snake, the snake being cobra in 37%, puff adder in 20% and the black and green mamba in 18% of the cases. Most of the bites occurred on the leg, below the knee. Treatment of snake envenomation consisted mainly of the administration of antibiotics (151 cases), analgesics (144 cases), antivenom tropical snake polyvalent (ATT) (89 cases), antitoxoid tetanus (TT) (61 cases), antihistamines (47 cases) and traditional medicines (43 cases). This study indicates that snake envenomation in rural Zimbabwe is common but fatalities are relatively rare. Language: en

Education Policy and Gender in Zimbabwe

Abstract: At independence in 1980 the government of Zimbabwe placed emphasis on equity in general policy statements. The existing unequal position of, and discrimination against, women in Zimbabwean society were acknowledged. Despite the government's stated commitment to gender equity little meaningful change to redress sexual inequalities in education occurred during the 12 years following independence. This paper discusses the changes and continuities in education policy, with reference to gender, during the colonial and post‐colonial periods.

The Fractal Distribution of Gold Deposits: Two Examples from the Zimbabwe Archaean Craton

Abstract: Gold deposits in two study areas in the Zimbabwe Archaean craton have fractal spatial distributions over a length scale from 2.5 to 25 km. The number of squares of side d necessary to cover every deposit is proportional to a power of the length of the square, and the number of deposits within a circle of radius r is proportional to a power of the radius. The fractal dimension, given by the exponent of the length scale in each method, is approximately 1. The fractal relations for both study areas are very similar. The distributions of deposits are interpreted as the result of hydrothermal mineralization by fractal fluid systems focussed in deformation zones.

Characterization of cohesion, friction and sensitivity of two hardsetting soils from Zimbabwe

Abstract: Hardsetting soils are defined as those which develop very high strength with little observable structure when they dry, but lose much of their strength when wet. Sandy loam soils (haplic lixisol) which showed typical hardsetting behaviour in the field were identified in a small-scale farming are in Zimbabwe. They were too hard to cultivate when dry, and produced a cloudy structure when plowed by a tractor in a slightly moist state. Samples of two sandy loam topsoils were collected, prepared at different water contents varying from saturated to field-dry and tested for stress-deformation and shear strength behavior in a direct shear box. For both soils at water contents above 10 g 100 g−1, the stress-deformation curves are of the plastic material type with continually increasing shear stress with deformation. At water contents less than 10 g 100 g−1, curves associated with more brittle material behavior resulted, with a peak shear stress reached at 3–4 mm deformation followed by a considerable loss in strength. At nearly all of the water contents, the angle of friction was 34–37° for both soils, but cohesion changed from nearly zero at saturation to well over 100 kPa in the field-dry state. The contribution of matric tension alone to soil cohesion is more than enough to account for the observed increases in strength on soil drying, and the potential role of soluble silicate cementing agents does not appear to be a factor in the case of these two soils.

Epidemiology of Hymenolepis nana infections in primary school children in urban and rural communities in Zimbabwe.

Abstract: Fecal specimens were obtained on 3 occasions at 10-12 wk intervals from 315 children in 3 rural villages in Zimbabwe and from 351 children in the high-density suburbs of an adjacent small town. Specimens were examined qualitatively and quantitatively for eggs of Hymenolepis nana, and these were found in 142 (21%) children. Infections occurred more frequently in younger children in the urban area but in older children in rural areas. The prevalence in urban areas (24%) was higher than in rural areas (18%), and in urban areas infection correlated with low "hygiene scores" (determined by observation) and with the presence in the household of an infected sibling. The prevalence of infection in the 3 rural communities did not correlate with availability of water, number of households per toilet, with low "hygiene scores," or with the presence of an infected sibling. Treatment with a single oral dose of 15 mg/kg praziquantel cured 84% of the infected children. New or reinfections occurred more frequently in households that had an infected sibling in an urban but not rural setting. The study demonstrates distinct differences in the transmission of H. nana infection in rural and urban communities. The data suggest intrafamily transmission in urban areas, particularly in households with poor hygiene behavior, leading to primary infection early in life. In rural areas, the prevalence of infection and the incidence of reinfection were highest in children of school age, and there was little evidence for intrafamily transmission of the parasite.

Condom use and the risk of HIV infection: who is being protected?

Abstract: Descriptive baseline data at enrollment into a cohort of male factory workers who were tested for HIV serology and monitored for sero-conversion over time, were analysed for condom use. At recruitment, the 1,146 men were asked about their sexual behaviour, history of sexually transmitted diseases (STDs), condom use and circumstances under which condoms were used. HIV seroprevalence in the cohort was 18.2 pc. Self reported use of condoms was low, with only 5 pc of the men reporting using them all the time. Forty four pc reported that they had never used a condom, 11.5 pc tried a condom only once, and 30.5 pc used condoms less than half the time. HIV positive men were more likely (Odds Ratio [OR] = 2.2 95 pc CI: 1.3-3.3) to use condoms than those who tested negative. Men using a condom more than once were younger and had more education (p values < 0.0005). Univariate analysis showed that men with self reported risk factors for HIV infection were more likely to use condoms. Significantly more condom users reported paying for sex, multiple sex partners or (for married men) a girlfriend (p < 0.005). Condom users also more often had a history of genital ulcers, urethral discharge or other STDs. Few married men (24 pc) reported using a condom with their wives. Condom use was more commonly reported with commercial sex workers (44 pc) or other extramarital partners (36 pc). Some risk factors for HIV infection were also present amongst men who reported that they did not use condoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of eutrophication control in Lake Chivero, Zimbabwe, by multivariate analysis of zooplankton

Abstract: Zooplankton was a useful tool in evaluation of eutrophication control in Lake Chivero, a tropical man made impoundment. Principal component analysis revealed both spatial and temporal changes in zooplankton community structure which were related to nutrient inflows as well as changes in nutrient content of the lake. Studies on filtration rates of different algae by Bosmina longirostris and Daphnia lumholtzi demonstrated that the response of zooplankton to eutrophication was related to their inability to utilize colonial algal species that develop in a nutrient rich-environment.

The Effects of Oral Chloroquine Administration on Kidney Function

Abstract: The effects of 3 consecutive days of oral chloroquine (1 mg/100 g body weight) on kidney function and blood pressure were studied in male Sprague-Dawley rats that were challenged with hypotonic saline infusion 24 h after the last chloroquine administration. The rats were anesthetized with Inactin [5 ethyl-5-(1'-methylpropyl)-2-thiobarbiturate, Byk Gulden] and continuously infused with 0.077 M NaCl for 8 h; urine flow and electrolyte excretion rates were monitored during the last 5 h. Blood pressure and glomerular filtration rates were also measured. Kidney function was compromised in chloroquine-treated rats, which retained significantly more of the infused Na+ and Cl- by comparison to control-vehicle-treated rats. Throughout the experimental period, chloroquine-treated rats exhibited low blood pressure (80 mm Hg vs. 127 mm Hg) which was associated with low glomerular filtration rate. The plasma aldosterone concentrations were significantly (p < 0.01) elevated in rats pretreated with chloroquine at the end of the 8-h infusion of hypotonic saline, but corticosterone levels were significantly (p < 0.01) lower in the treated rats. It is concluded that chloroquine administration impairs kidney function, resulting in inappropriate Na+ and Cl- retention. This effect is likely to be mediated via chloroquine-induced increases in plasma aldosterone concentration and lowering of GFR.

Spatial pattern, regeneration and growth rates of Brachystegia spiciformis and Julbernardia globiflora

Abstract: Past work on tree-to-tree interactions in semi-arid savannas, through the use of nearest neighbour analysis, has shown both a regular dispersion pattern and a positive correlation between the size of a tree and the distance to its nearest neighbour. From these results, the importance of competition has been inferred. In the present study, tree-to-tree interactions in a mesic savanna woodland at Marondera, Zimbabwe, dominated by relatively small-sized individuals of Brachystegia spiciformis and Julbernardia globiflora, were examined. Results show that the regular dispersion pattern is uncommon; that there are few significant positive correlations between size of individual and distance to nearest neighbour; and that growth rate is not consistently correlated with size and distance of nearest neighbour. Results of a study of regeneration relative to canopy cover suggest a possible mechanism for these findings: unlike semi-arid savannas, young plants often grow in under-canopy environments so that early spacing of young trees does not occur. Significant positive correlations between the size of a tree and the distance to its nearest neighbour were found in a stand of larger, presumably older, trees, suggesting that such a relationship only develops in mesic miombo woodland through a thinning process as the trees mature. Familial clumping, which is common in the study area, may mask spatial patterns.