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Biomedical subjects

D Wilkinson

Publications and source records attributed to D Wilkinson.

At least 127 records · Page 7Linked to original sources
PubMed1999

The role of stimulus factors in making categorical and coordinate spatial judgments.

We report three experiments which investigate the lateralization of categorical and coordinate processing. In all experiments, participants judged the position of a dot relative to a line. We manipulated display luminance (controlling for contrast), polarity (black-on-white versus white-on-black displays), and exposure duration (100, 150, and 200 ms). The results showed a left visual field-right hemisphere advantage for coordinate judgments, but only under highly prescribed conditions. We argue that stimulus and procedural factors are critical in determining the hemisphere by task interaction.

Brain↗
PubMed1999

Spatial implications of the tuberculosis DOTS strategy in rural South Africa: a novel application of geographical information system and global positioning system technologies.

We used GIS/GPS technology to document and quantify improved access to tuberculosis treatment through a community-based programme in Hlabisa, South Africa. We plotted tuberculosis supervision points used by the district health system in 1991 (programme's first year) and 1996 (programme fully established), and quantified access by using GIS to measure the mean distance from each homestead in the district to hospital, clinics, community health workers (CHW) and volunteer supervisors. While the tuberculosis caseload tripled, the number of community supervision points used increased from 37 in 1991 to 147 in 1996. Adding clinics and then CHWs to the hospital as treatment points reduced the mean distance from homestead to treatment point from 29.6 km to 4.2 km and to 1.9 km, respectively. Adding volunteers further decreased the distance to 800 m. GIS/GPS effectively documents and quantifies the impact of community-based tuberculosis treatment on access to treatment.

Humans↗
PubMed1999

Establishing a new university department of rural health: the first 2 years of the South Australian Centre for Rural and Remote Health.

This study aimed to describe the establishment of a new University Department of Rural Health (UDRH) in South Australia and to report early achievements. In May 1997, the UDRH was established, key staff were recruited, infrastructure was developed and in April 1998 a Joint University Committee on Rural and Remote Health was formed. By mid-1999, 14 full-time equivalent staff were employed in Whyalla and Adelaide. Early achievements include: review of undergraduate rural placements; increased rural clinical placements by 1000 student-weeks; partnership with the Dental School resulting in training opportunities and falling public waiting lists; multidisciplinary teaching practices in four rural sites; priority public health projects established; competitive research grants won; and a capital grant to strengthen Aboriginal health services infrastructure secured. These early achievements demonstrate UDRH potential to have a real impact on health worker education, service delivery, and public health status in rural and remote areas. This strong foundation must now be built on.

Curriculum↗
PubMed1999

Impact of prematurity on admissions to the neonatal nursery of a rural South African district hospital.

The objectives of this study were to determine causes of admission to a district hospital neonatal nursery; to describe outcomes; and to determine risk factors for these outcomes. The study was based at the neonatal nursery of Hlabisa hospital, KwaZulu/Natal; 149 consecutive admissions to the nursery between May and November 1995 were audited. The main outcome measures were diagnosis, gestational age, birthweight, critical event during admission (sepsis, severe vomiting, diarrhoea, jaundice, fits, apnoea), and outcome (discharged alive, death, discharged with deficit). Most admitted neonates (73; 54 per cent) were aged less than 37 weeks at birth, and 123 (84 per cent) weighed less than 2.5 kg. Prematurity and low birthweight accounted for 114 (81 per cent) admissions. In all, 58 (39 per cent) neonates experienced a total of 72 critical events, the most frequent being sepsis (39; 54 per cent). Although most (114; 77 per cent) were discharged well, 20 (15 per cent) died and three (3 per cent) were discharged with a significant deficit. Sepsis and apnoea were most frequent among the lightest and most immature babies, while fits were more frequent among heavier, mature babies. In a multivariate model, experiencing any critical event (odds ratio [OR] 15.6; 95 per cent CI 3.0-82.6, p = 0.001) was the only significant independent risk factor for mortality, although birthweight (p = 0.068) and gestational age (26-30 vs. > or = 37 weeks; OR 5.6, 95 per cent confidence internal [CI] 0.3-95.7, p = 0.23), further contributed to risk of death. We conclude that a substantial proportion (around 27 per cent) of district perinatal mortality occurs in the neonatal nursery. Several simple and effective interventions exist to minimize neonatal loss in district hospitals in South Africa.

Analysis of Variance↗
PubMed1999

Gated TI-201 myocardial perfusion SPECT: application of energy window optimization.

PURPOSE: TI-201 scintigraphy is plagued with poor image quality because of the low-energy photons of TI-201 decay. Traditionally, a narrow 20% window centered on 71-72 keV has been used to improve sensitivity. Recent studies indicate that better imaging may be possible by optimizing the energy window to 34% centered on 77 keV. In this study, energy window optimization (EWO) was applied to gated TI-201 myocardial perfusion SPECT, and myocardial functional parameters were compared for gated TI-201 SPECT and gated Tc-99m sestamibi (Tc-99m MIBI) SPECT. METHODS: Count statistics for standard and optimal TI-201 myocardial scintigraphy were noted in 25 patients by assessing the total counts in a mid-ventricular slice of a rest-gated TI-201 myocardial SPECT study. The feasibility of performing functional studies with the application of EWO to TI-201 was assessed using the count statistics of a mid-ventricular slice of an optimized gated TI-201 SPECT study and a gated Tc-99m MIBI SPECT study. The functional parameters (ejection fraction, wall motion, and thickening) of TI-201 with EWO and Tc-99m MIBI were compared in 60 patients who underwent rest-gated TI-201 SPECT followed by poststress gated Tc-99m MIBI SPECT. The left ventricular ejection fraction was calculated using commercially available software, whereas wall thickness and motion were assessed by the consensus of two readers. RESULTS: The application of EWO increased available counts by more than 25%. It also resulted in sufficient counts being available to perform gated TI-201 SPECT without increasing acquisition times or the dose of TI-201. The average ejection fraction was 60.4% for gated TI-201 SPECT and 59.6% for gated Tc-99m MIBI SPECT (not significantly different). Overall, the image quality was rated excellent in 12% for TI-201 and Tc-99m MIBI and good in 50% and 62%, respectively, and poor in 38% and 26%, respectively. CONCLUSION: The application of EWO to TI-201 SPECT allows myocardial functional parameters to be assessed without having to increase the acquisition times or the administered dose of TI-201.

Adult↗
PubMed1999

STD syndrome packets: improving syndromic management of sexually transmitted diseases in developing countries.

OBJECTIVE: To design, introduce, and evaluate "STD syndrome packets" containing recommended drugs for each syndrome, four condoms, a partner treatment card, and a patient information leaflet, with the goal of improving sexually transmitted disease (STD) case management. METHODS: Packet design evolved around available packaging technology, informed by pilot testing with nurses working in primary care clinics, doctors in private medical practices, and patients with an STD, in Hlabisa, South Africa. Evaluation 1 year later included analysis of distribution records and interviews with 16 nurses and 64 patients. RESULTS: A cheap packet (2 U. S. cents each, excluding contents) compatible with current legislation was designed and introduced to six public sector clinics and as a short pilot to five private medical practices. Four thousand eighty-five packets were distributed to the clinics, equivalent to approximately 115% of the STDs reported over that period. All 16 nurses reported using the packets, but only 63% did so all the time because of occasional supply problems. All believed the packets improved treatment by saving time (75%), improving supply of condoms and partner cards (44%), and making treatment easier (56%). Patients also responded positively, and most said they would buy a packet (up to $5) at a pharmacy (84%) or store (63%) if available. CONCLUSIONS: The STD syndrome packets have the potential to improve STD syndromic management by standardizing therapy and improving the supply of condoms, partner cards, and information leaflets. Packets are popular with practitioners and patients, but consistent supply is essential for maximal impact. There may be scope for social marketing of the packets, which could further increase use.

Anti-Infective Agents↗
PubMed1999

Leptin is released from the human brain: influence of adiposity and gender.

Leptin, a 16-kDa circulating protein primarily derived from adipocytes, is an important factor in the regulation of appetite and energy expenditure. Using simultaneous arterio-venous blood sampling, several organs were assessed with regard to their individual roles in leptin metabolism in healthy male and female subjects constituting a range of body mass indices. Plasma leptin levels were unchanged after passage through the hepatosplanchnic and forearm circulations. In contrast, concentrations in the renal vein were consistently lower than those in the renal artery (-15%; P<0.005), indicating net extraction, whereas the brain was observed to be a net leptin releaser. Concentrations in the internal jugular vein were significantly higher than arterial levels in lean females (change, 3.0+/-1.2 ng/mL; P<0.02) and in obese males (body mass index, >28 kg/m2), but not lean (change, 2.3+/-2.3 vs. 0.1+/-0.1 ng/mL, respectively; P<0.05), indicating a probable influence of both gender and adiposity on brain leptin release. An attempt to grossly localize the site of brain release by using cerebral venous scans to distinguish between jugular venous drainage from cortical and subcortical brain areas revealed no region-specific secretion. These data raise the possibility that the brain is a nonadipose source of leptin. In addition, the higher level of brain release observed in females may contribute to the well documented gender differences in overall plasma leptin levels.

Adipose Tissue↗
PubMed1999

HIV infection among women admitted to the gynaecology service of a district hospital in South Africa.

Our objective was to determine the prevalence of HIV infection and disease-specific HIV prevalence among women admitted to the gynaecology service of a district hospital in South Africa over a 3-month period in 1997. This was done with the goal of developing HIV education and counselling services in this setting. HIV status was determined among 196 (96%) of 205 consecutive admissions; 82 (42%) tested HIV positive. The HIV-infected women were younger than the HIV uninfected women (mean age 27 vs 33 years, P=0.001). The disease-specific HIV prevalence was > or = 40% among women who had had abortions, pelvic inflammatory disease, or ectopic pregnancy. The length of hospital stay (mean 5.4 days) and mortality (1%) were similar in the 2 groups. Inpatient gynaecology services may be an important setting in Africa, within which to provide HIV education, counselling and care.

Adult↗
PubMed1999

Inadequate treatment for sexually transmitted diseases in the South African private health sector.

Correct management of sexually transmitted diseases (STDs) is important for their control, and to reduce HIV transmission. Guidelines on syndromic management of STDs were introduced by the provincial Department of Health in KwaZulu/Natal (KZN) in South Africa in 1995. The drug treatment provided for STDs by the 11 private general practitioners in one rural district was assessed and compared with provincial guidelines. Information was gathered through semistructured interviews which asked the 11 doctors, who all dispense prescribed drugs as part of the consultation fee, how they would treat 3 hypothetical cases of STD syndromes. In all 33 prescriptions, the treatment did not correspond exactly with provincial recommendations and only 3 (9%) were adequate. All other prescriptions were inadequate because dose or duration was incorrect in 6 (18%), or because incorrect drugs were prescribed in 24 (73%) of cases. Eight of the 11 doctors did not provide adequate treatment for any of their cases. A continuing medical education programme for the doctors and their staff was devised to improve the STD treatment in the private sector in this South African district.

Adult↗
PubMed1999

Routine reporting or sentinel surveys for HIV/AIDS surveillance in resource-poor settings: experience in South Africa, 1991-97.

Information from routine and sentinel surveillance was used to monitor the HIV/AIDS epidemic in KwaZulu-Natal, South Africa between 1991 and 1997. Comparisons were made between data obtained from (1) sentinel surveillance for antenatal HIV infection, pulmonary tuberculosis (PTB), and AIDS in a single health district and (2) province-wide sentinel surveillance for antenatal HIV infection, legally required notification of cases of PTB, and voluntary notification of AIDS cases. HIV prevalence among antenatal clinic attenders in the sentinel district rose rapidly and at similar rates to provincial figures: 4.2% vs 4.8% in 1992 to 25.9% vs 26.9% in 1997. PTB incidence increased four-fold in the sentinel district over the study period, whereas provincial PTB figures from passive surveillance fluctuated widely and showed no clear increase (Chi-square for trend 425.5, P<0.00001). AIDS incidence in the sentinel district increased dramatically while provincial data from the voluntary reporting system showed a less consistent and much slower rise (Chi-square for trend 9.07, P=0.003). Incidence of AIDS in 1997 was estimated as 437/10(5) in the sentinel district compared to 32/10(5) in the provincial figures. Routine disease notification and voluntary reporting systems are likely to underestimate the impact of the HIV/AIDS epidemic in resource-poor settings. Sentinel surveillance at representative sites should be developed to validate or replace passive surveillance systems.

AIDS-Related Opportunistic Infections↗
PubMed1999

Unrecognized sexually transmitted infections in rural South African women: a hidden epidemic.

Sexually transmitted infections (STIs) are of major public health concern in developing countries, not least because they facilitate transmission of human immunodeficiency virus (HIV). The present article presents estimates of the prevalence, on any given day, of STIs among women in rural South Africa and the proportion who are asymptomatic, symptomatic but not seeking care, and symptomatic and seeking care. The following data sources from Hlabisa district were used: clinical surveillance for STI syndromes treated in health facilities, microbiological studies among women attending antenatal and family planning clinics, and a community survey. Population census provided denominator data. Adequacy of drug treatment was determined through quality of care surveys. Of 55,974 women aged 15-49 years, a total of 13,943 (24.9%) were infected on any given day with at least one of Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, or Treponema pallidum. Of the women investigated, 6697 (48%) were asymptomatic, 6994 (50%) were symptomatic but not seeking care, 238 (1.7%) were symptomatic and would seek care, and 14 (0.3%) were seeking care on that day. Only 9 of the 14 women (65%) were adequately treated. STIs remained untreated because either women were asymptomatic or the symptoms were not recognized and acted upon. Improved case management alone is therefore unlikely to have a major public health impact. Improving partner treatment and women's awareness of symptoms is essential, while the potential of mass STI treatment needs to be explored.

Adolescent↗
PubMed1999

Eight years of tuberculosis research in Hlabisa--what have we learned?

An 8-year research-service collaboration in tuberculosis (TB) in Hlabisa has yielded important data on the emerging HIV-related TB epidemic in South Africa, demonstrating a substantial increase in caseload, HIV prevalence and mortality. A successful, cost-effective, community-based programme of directly observed therapy, utilising volunteers, clinics and community health workers, has helped ensure adherence to therapy. As the caseload has increased, however, case-holding has started to fall, suggesting the need for more effective defaulter-tracing strategies. More fundamental work has studied the molecular epidemiology of TB, suggesting that much of the disease is recently, and casually, transmitted. This collaborative experience may be a model for efforts to control other important public health problems.

AIDS-Related Opportunistic Infections↗
PubMed1999

Prevalence of infection with human herpesvirus 8/Kaposi's sarcoma herpesvirus in rural South Africa.

OBJECTIVE: To determine prevalence of infection with human herpesvirus 8 (HHV-8)/Kaposi's sarcoma herpesvirus (KSHV) and to gain some insight into possible transmission dynamics of this novel virus in South Africa. METHODS: Stored, anonymous serum from 50 patients with a sexually transmitted disease (STD), 50 adult medical ward patients (25 male, 25 female), and 36 paediatric ward patients in Hlabisa Hospital, KwaZulu-Natal, was screened by enzyme-linked immunosorbent assay (ELISA) for antibodies to the small capsid-related protein encoded by HHV-8/KSHV orf65. Antibodies to the latency-associated nuclear antigen (LANA) were measured by immunofluorescence, and sera that were reactive in the ELISA but negative by immunofluorescence were re-tested by Western blot against the recombinant orf65 protein to exclude nonspecific reactivity. RESULTS: Overall, 47 patients tested positive (34.6%), 76 tested negative (55.9%) and 13 (9.5%) had indeterminate results. Among those with a definite result, prevalence was similar among males (47.2%) and females (52.8%) and increased in later adulthood (< 18 months 37.5%, 19-120 months 38.5%, 15-34 years 32.1%, 35-69 years 62.8%). Prevalence was highest among medical patients (58.1%); among those with an STD it was 31.1% (P = 0.01), and among children it was 22.8% (P = 0.001). When age-adjusted, prevalence among medical patients (23.7%) was similar to that among patients with an STD. CONCLUSION: Prevalence of HHV-8/KSHV is high in this setting and transmission appears to be occurring in childhood as well as among adults. Larger population-based studies are required to detail the transmission dynamics of HHSV-8/KSHV.

Adult↗
PubMed1999

Emergence of multidrug-resistant tuberculosis in a community-based directly observed treatment programme in rural South Africa.

OBJECTIVE: Although little studied in developing countries, multidrug-resistant tuberculosis (MDR-TB) is considered a major threat. We report the molecular epidemiology, clinical features and outcome of an emerging MDR-TB epidemic. METHODS: In 1996 all tuberculosis suspects in the rural Hlabisa district, South Africa, had sputum cultured, and drug susceptibility patterns of mycobacterial isolates were determined. Isolates with MDR-TB (resistant to both isoniazid and rifampicin) were DNA fingerprinted by restriction fragment length polymorphism (RFLP) using IS6110 and polymorphic guanine-cytosine-rich sequence-based (PGRS) probes. Patients with MDR-TB were traced to determine outcome. Data were compared with results from a survey of drug susceptibility done in 1994. RESULTS: The rate of MDR-TB among smear-positive patients increased six-fold from 0.36% (1/275) in 1994 to 2.3% (13/561) in 1996 (P = 0.04). A further eight smear-negative cases were identified in 1996 from culture, six of whom had not been diagnosed with tuberculosis. MDR disease was clinically suspected in only five of the 21 cases (24%). Prevalence of primary and acquired MDR-TB was 1.8% and 4.1%, respectively. Twelve MDR-TB cases (67%) were in five RFLP-defined clusters. Among 20 traced patients, 10 (50%) had died, five had active disease (25%) and five (25%) were apparently cured. CONCLUSIONS: The rate of MDR-TB has risen rapidly in Hlabisa, apparently due to both reactivation disease and recent transmission. Many patients were not diagnosed with tuberculosis and many were not suspected of drug-resistant disease, and outcome was poor.

Antitubercular Agents↗
PubMed1999

Traditional healers as tuberculosis treatment supervisors: precedent and potential.

SETTING: Hlabisa, South Africa. OBJECTIVE: To determine precedent and potential for traditional healers to act as tuberculosis (TB) treatment supervisors. METHODS: Literature review to describe precedent for the involvement of traditional healers in TB treatment supervision. Interviews with 100 TB patients to determine use of healers and their acceptability as supervisors. Interviews with 24 healers in the project sub-district to determine willingness to act as supervisors. RESULTS: Despite extensive literature on the interaction between traditional healers and conventional health services, including descriptions of traditional understandings of TB, no published work was identified that reported supervision of TB patients by traditional healers. Of 100 patients interviewed, only 10% had used a healer as the first health provider for their illness, but 40% had attended a healer at some time prior to diagnosis. Although only 4% believe healers can cure TB, 84% would consider choosing a healer as a treatment supervisor. Of the 24 healers, 15 (63%) distinguished between two types of diagnosis made among patients with symptoms suggestive of TB: TB and idliso. Idliso is poisoning or bewitching, and is said to be best cured by healers, while TB is infectious and cannot be cured by healers. Most healers (88%) reported having referred patients with possible TB to hospital in the past; all were keen to negotiate collaboration with health services, and 92% were willing to act as treatment supervisors. CONCLUSIONS: While there is little reported precedent for traditional healers to interact formally with tuberculosis treatment services, the potential for collaboration seems to be high, at least in our setting.

Adult↗