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Biomedical subjects

D W Mulder

Publications and source records attributed to D W Mulder.

At least 37 records · Page 2Linked to original sources
PubMed1994

Risk factors for HIV-1 infection in adults in a rural Ugandan community: a population study.

OBJECTIVE: To determine sociodemographic risk factors associated with HIV-1 infection in a rural Ugandan population. DESIGN: A population-based survey. METHODS: All adult residents (aged > or = 13 years) in a cluster of 15 neighbouring villages of the Masaka District of south-west Uganda were invited to participate in a sociodemographic and serological survey. Questions relating to sexual behaviour were asked separately in an accompanying case-control study. Socioeconomic data and an unambiguous HIV-1 serostatus were obtained by house-to-house survey for 3809 (72%) of the adult population. The association between serostatus and the following variables were analysed: age, sex, marital status, tribe, religion, education, occupational group, place and frequency of travel and recent history of sexually transmitted disease. RESULTS: Women aged 13-21 years were at a much higher risk than men of the same age [odds ratio (OR), 8.6; 95% confidence interval (CI), 3.0-24.5]. Married people aged < 25 years were twice as likely to be infected as those who were not currently married (OR, 2.3; 95% CI, 1.5-3.7). In contrast, in those aged > or = 25 years, women were at a lower risk than men (OR, 0.72; 95% CI, 0.52-0.98) as were those who were currently married compared with those who were not (OR, 0.47; 95% CI, 0.34-0.64). In both age groups those with a history of a recent genital ulcer were approximately three times more likely to be infected. Muslims had lower risks than non-Muslims (OR, 0.58 for both age groups). CONCLUSIONS: The people most at risk of HIV-1 infection in this rural Ugandan population are young married women who had, presumably, commenced sexual activity recently.

Adolescent↗
PubMed1994

HIV-1 incidence and HIV-1-associated mortality in a rural Ugandan population cohort.

OBJECTIVE: To determine the incidence of HIV-1 infection and HIV-1-associated mortality in a rural Ugandan population. DESIGN: A prospective cohort study. METHODS: A cohort consisting of the population (de jure census 9820) of a cluster of 15 villages in Masaka District, south-west Uganda was enrolled between 1989 and 1990 through a demographic and medical survey. The HIV-1 seroprevalence rate was 4.8% for all ages combined and 8.2% for those aged 13 years or more. The survey was repeated after 1 year. RESULTS: The 1-year HIV-1 incidence rate among adults was 1% [9.2 per 1000 person-years of observation; 95% confidence interval (CI), 5.5-12.9). A total of 84 deaths were observed. In adults, half of all deaths (31 out of 60) were in HIV-1-seropositive individuals. The age-adjusted overall mortality rate ratio for HIV-positive adults compared with HIV-negatives was 20.8 (95% CI, 12.0-35.7). In the 13-44 age group the corresponding rate ratios for men, women and both sexes combined were 16.3, 108.9 and 58.7, respectively. The HIV-attributable mortality fractions, i.e., the proportion of deaths that would have been avoided in the absence of HIV, were 44, 50 and 89% for adult men, adult women and adults aged 25-34 years (both sexes combined), respectively. The 1-year progression to death among HIV-1-seropositive adults was 10.3%. CONCLUSION: These results demonstrate the profound impact that the HIV-1 epidemic has on adult mortality in a rural area of Uganda where the HIV-1 prevalence and incidence rates in adults are 8 and 1%, respectively.

Adolescent↗
PubMed1994

Risk factors for HIV-1 infection in adults in a rural Ugandan community: a case-control study.

OBJECTIVE: To study in depth sexual history and sexual behaviour variables as risk factors for HIV-1 infection in a rural Ugandan population. METHODS: Following a socioeconomic and serological survey of a rural population in Masaka District, south-west Uganda, 233 randomly selected HIV-1-positive cases and 233 negative controls matched on age and village of residence, were invited in October 1990 to participate in a case-control study. A total of 132 cases and 161 controls attended for in-depth investigation including an interview about sexual behaviour. RESULTS: The factor most strongly associated with increased risk of infection was a greater number of lifetime sexual partners, with odds ratios (OR) of 2.1 and 4.9 for those reporting 4-10 and 11 or more partners, respectively, compared with those reporting less than four partners. Having only one sexual partner did not provide complete protection, a total of seven (one male, six female) subjects reporting only one sexual partner were HIV-1-positive. Other significant factors were a history of genital ulcers [OR, 2.9; 95% confidence intervals (CI), 1.0-9.1) and not being a Muslim (OR, 5.4; 95% CI, 1.8-16.5) suggesting a possible protective effect of circumcision. There was a suggestion that those who married within the last 7 years (OR, 2.4; 95% CI, 0.9-6.1) and men exposed to menstrual blood (OR, 5.7; 95% CI, 0.7-49.8) were at an increased risk of HIV-1 infection. CONCLUSIONS: These results confirm the predominant role of sexual behaviour in the HIV-1 epidemic. Of particular concern is the observation of HIV-1 infection among those reporting only one partner. Where HIV-1 infection is widely distributed in the general population, risk reduction strategies should, in addition to the promotion of partner reduction, place strong emphasis on safe-sex techniques.

Adolescent↗
PubMed1994

Computer-assisted quality assurance in an HIV serology laboratory.

A computer-based quality assurance programme for an HIV-1 serology laboratory is described. The programme was designed to minimise transcription errors and to provide rapid feedback on laboratory performance. Similar systems could readily be introduced to any laboratory with access to simple computing facilities.

AIDS Serodiagnosis↗
PubMed1993

Algorithms for detecting antibodies to HIV-1: results from a rural Ugandan cohort.

OBJECTIVE: To evaluate an algorithm using two enzyme immunoassays (EIA) for anti-HIV-1 antibodies in a rural African population and to assess alternative simplified algorithms. METHODS: Sera obtained from 7895 individuals in a rural population survey were tested using an algorithm based on two different EIA systems: Recombigen HIV-1 EIA and Wellcozyme HIV-1 Recombinant. Alternative algorithms were assessed using negative or confirmed positive sera. RESULTS: None of the 227 sera classified as unequivocably negative by the two assays were positive by Western blot. Of 192 sera unequivocably positive by both assays, four were seronegative by Western blot. The possibility of technical error cannot be ruled out in three of these. One of the alternative algorithms assessed classified all borderline or discordant assay results as negative had a specificity of 100% and a sensitivity of 98.4%. The cost of this algorithm is one-third that of the conventional algorithm. CONCLUSIONS: Our evaluation suggests that high specificity and sensitivity can be obtained without using Western blot and at a considerable reduction in cost.

Algorithms↗
PubMed1993

General and HIV-1-associated morbidity in a rural Ugandan community.

OBJECTIVES: The AIDS epidemic in sub-Saharan Africa affects whole communities, adding to the already high burden of morbidity. Reports of AIDS cases are usually from hospital attenders, often diagnosed using the World Health Organization (WHO) clinical case definition. Little is known about the extent of HIV-associated morbidity in the general population. The objectives of this study were to describe the prevalence of (1) markers of general morbidity and (2) the criteria of the WHO clinical case definition for AIDS and (3) to determine the association between these markers and HIV-1 serostatus in a rural Ugandan community. METHODS: A survey was conducted among the adult population (aged > or = 13 years) of 15 neighbouring villages in Masaka District, south-west Uganda. The survey included medical history, physical examination and testing for HIV-1 antibodies. RESULTS: The HIV-1 seroprevalence among 4175 out of 5278 (79%) eligible adults was 8.2%. Current health problems were reported by 57.6% of adults, with increased rates in HIV-1-positive subjects, women and older people. Five of the 10 most common complaints showed significant associations with HIV-1 status, as did reported genital ulcer and vaginal discharge. The crude HIV-1 attributable disease burden in the population was 1.2% for current illness, 4.3% for previous serious illness and 9.9% for illness leading to hospital admission. Overall, 11 (3.3%) of the HIV-1-positive and nine (0.2%) of the HIV-1-negative subjects had AIDS as defined by the clinical case definition. The positive and negative predictive values and specificity were 55.0, 92.0%, and 99.8%, respectively. CONCLUSIONS: Against a background of high general morbidity, we observed a relatively small population attribution of HIV-1-associated morbidity. The results indicate that the clinical AIDS case definition may provide a useful tool for population surveys.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Community-based HIV/AIDS research--whither community participation? Unsolved problems in a research programme in rural Uganda.

Involvement of the study community in research on HIV/AIDS has presented the MRC/UVRI programme in rural Uganda with a multi-layered challenge. A typology developed in agricultural research which defines different levels of community participation in research is described where participation may be at 'contract', 'consultative', 'collaborative' and 'collegiate' level (each level indicating an increasing degree of community participation). Community involvement in the MRC/UVRI Programme is then outlined and the typology applied. It is shown that the majority of community participation in the Programme is at the contract level since the nature of the research programme as a 'foreign imposition' with 'foreign goals' has precluded the involvement of the community in much of the policy development and research planning. However, it is noted that as the Programme becomes more established in the area community influence grows and signs of community impact on policy and increased research inputs are beginning to be seen. The question is raised as to whether it is realistic to expect that externally imposed health research, particularly on sensitive topics, can ever be truly community participatory research.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Antecedent medical diseases in patients with amyotrophic lateral sclerosis. A population-based case-controlled study in Rochester, Minn, 1925 through 1987.

Odds ratios (ORs) were estimated for the prevalence of antecedent endocrine, metabolic, or vascular diseases among 45 patients with amyotrophic lateral sclerosis from the Rochester, Minn, population compared with 90 control subjects matched for sex, year of birth, period of observation, and residence. Hypertension occurred less frequently in male patients with amyotrophic lateral sclerosis (4%) than in control subjects (30%; OR = .10). Because of small population size, no conclusions can be drawn with respect to the following antecedent conditions: thyroid disease (OR = 1.61), coronary artery disease (OR = .58), obesity (OR = .52), diabetes (OR = 1.00), cerebrovascular disease (OR = .21), and peripheral vascular disease (OR = 1.23). The heterogeneity of antecedent thyroid disease makes it highly unlikely that any specific thyroid lesion is causally associated with most cases of amyotrophic lateral sclerosis. Hypertension may be a marker for protective factors against the development of amyotrophic lateral sclerosis in men.

Aged↗
PubMed1991

Psychologic and adaptational difficulties anteceding amyotrophic lateral sclerosis: Rochester, Minnesota, 1925-1987.

Comprehensive medical records of 45 amyotrophic lateral sclerosis (ALS) patients and 90 controls from the same community, matched by age, gender, and period of observation, were reviewed. Three (13%) of 23 men with ALS, 15 (33%) of 46 control men, 10 (45%) of 22 women with ALS, and 19 (43%) of 44 control women had antecedent psychologic or adaptational difficulties. The proportions of long-standing or serious conditions were comparable in all four groups. However, no man in whom ALS developed had a record of mild antecedent difficulties alone, whereas 3 would have been expected (p = 0.024).

Adaptation, Psychological↗
PubMed1991

When is an apparent excess of neurologic cases epidemiologically significant?

To conserve clinical and public health resources, it is necessary to screen reports from the community of an excess or cluster of cases of chronic neurologic diseases for potential epidemiologic significance, ie, to identify those clusters that may have occurred owing to the operation of an underlying etiologic cause rather than to chance alone. Traditionally, the probability that such a cluster has occurred by chance within the reporting community is computed, ignoring the fact that many other similar communities have not reported a cluster. We propose a modified approach that takes this larger universe of communities into account, thereby raising the threshold for potential epidemiologic significance. As a result, the lowest value for the ratio of observed-to-expected cases that may be considered of epidemiologic significance should be increased by factors of 2 for small clusters (one to three expected cases), 1.5 for intermediate clusters (seven to 30 expected cases), and 1.3 for large clusters (60 to 90 expected cases). Consequently, case ascertainment and full field investigations can be reserved for only those reports that, if confirmed, would represent a cluster not due to chance alone. We illustrate this with a case from our own experience.

Amyotrophic Lateral Sclerosis↗
PubMed1991

Wohlfart-Kugelberg-Welander syndrome: serum creatine kinase and functional outcome.

The medical records of 31 patients (19 male and 12 female) with clinical and electrophysiologic features of Wohlfart-Kugelberg-Welander syndrome were reviewed. The reported age at onset ranged from less than one year to 46 years, and the age at diagnosis ranged from three to 66 years. Proximal muscle weakness, especially of the lower extremities, and muscular atrophy were the predominant clinical features. Elevated serum creatine kinase levels were noted in four female and 12 male patients, and the degree of elevation was higher in the male patients (up to 32 times the upper limit of normal) than in the female patients. On initial evaluation, two patients were wheelchair-bound, whereas the others were ambulatory. On follow-up evaluation three to 32 years later (mean, 15.5 years), 11 patients used wheelchairs, although only three were wheelchair-bound. The disease followed a steady, slowly progressive course. The outcome of ambulatory status did not correlate with the initial creatine kinase determination.

Activities of Daily Living↗
PubMed1989

Prevalence of HIV-1 antibody among groups of patients and healthy subjects from a rural and urban population in the Mwanza region, Tanzania.

In April 1987, antibody to HIV-1 was determined in sera from 764 subjects from the Mwanza region in the north of Tanzania. Patients with a clinical suspicion of AIDS were HIV-1 antibody-positive in 65.4% (34 out of 52) and patients admitted for pulmonary tuberculosis in 25% (9 out of 36). In patients attending general outpatient departments (OPD), HIV antibody was found in 12.5% of 48 patients with a history of sexually transmitted disease (STD) and in 10.6% of 141 patients without such a history. In healthy subjects, HIV-1 antibody was present in 6% of 332 pregnant women and in 4.5% of 155 blood donors. Of the blood donors, pregnant women and OPD patients without a history of STD (628 subjects in all), 465 belonged to the rural population of the region and the majority were peasants. In this subgroup, the HIV-1 antibody prevalence was 4.8% in blood donors, 4.9% in pregnant women and 10.3% in OPD patients. This indicates a spread of HIV-1 among the population in this part of Tanzania. Further studies are needed to determine what proportion of the population is affected.

Adolescent↗
PubMed1987

Motor neuron disease: epidemiologic studies.

The etiology of motor neuron disease (MND) is unknown and treatment is limited to measures which sustain the patient. We review selected epidemiologic studies searching for a pattern in the clinical expression of MND which may reflect the operation of the underlying cause. Recognition of patterns of occurrence of MND might provide the basis for testable etiologic hypotheses for MND. In addition, recognition of the association of MND with diseases of known cause or the analogy of diseases of known cause with MND may provide further etiologic hypotheses.

Adult↗
PubMed1986

Amyotrophic lateral sclerosis: relationship between serum creatine kinase level and patient survival.

Various laboratory tests have been used to predict the survival of patients with amyotrophic lateral sclerosis (ALS). The serum creatine kinase (CK) level is frequently elevated in patients with ALS. This study evaluates the relationship between serum CK elevation and survival in patients with ALS and points to a lack of correlation. Thirty patients with ALS, who ranged in age from 21 to 73 years, were followed up from 7 to 57 months. All patients had neurologic and psychiatric evaluations, electromyographic examinations, and serum CK measurements. The CK level was elevated in 50% of the patients. On follow-up, 20 patients had died; ten of these had had elevated CK levels. The 3-year survival from the date of the examination was 47% for patients with elevated CK levels and 40% for patients with normal levels. This difference did not have statistical significance (p greater than 0.43).

Adult↗
PubMed1986

Follow-up study on amyotrophic lateral sclerosis in Rochester, Minn., 1925 through 1984.

The incidence, secular trend and survivorship of amyotrophic lateral sclerosis in the Rochester, Minn., population has been investigated over a 60-year period, 1925 through 1984. The crude average annual incidence rate was 2.0 per 100,000 population. The rate, age- and sex-adjusted to the US 1970 white population, was 2.4 per 100,000 population (3.0 for men and 2.0 for women), with a male to female ratio of 1.5:1. Incidence rates after 1955 showed a small but nonsignificant increase compared to those of the former 30-year period. Median age at onset was 67.5 years; the incidence rates increased significantly with advancing age, but without a peak. Median survivorship was 23.8 months, and younger patients had a better prognosis than patients with an advanced age at onset. No change in duration of survivorship was observed over the period studied. Two of the 44 patients (4.5%) had a family history of amyotrophic lateral sclerosis.

Age Factors↗