Search PubMed⌕ Search

Biomedical subjects

P R Mason

Publications and source records attributed to P R Mason.

At least 19 recordsLinked to original sources
PubMed2006

Human immunodeficiency virus, smoking and self-rated health in Harare, Zimbabwe.

SETTING: Twenty-two urban factories in Harare. OBJECTIVE: To determine the relationship between the human immunodeficiency virus (HIV), smoking and self-rated health in a high HIV prevalence urban workforce. DESIGN: Cross-sectional survey. RESULTS: Of 7482 employees, 6111 (82%) consented to interview and anonymous HIV serology; 88% were male; median age was 34 years. HIV prevalence was 19%. Current (median 6 cigarettes per day) and former smoking were reported by 17% and 7%, respectively. Smoking (current or former) was more common among HIV-positive (27%) than -negative participants (17%; P < 0.001). Factors significantly associated with being a smoker on multivariate analysis were being HIV-infected (OR 1.5, 95% CI 1.4-1.7), older age (P < 0.001), non-Christian (OR 1.6, 95% CI 1.2-2.2) and manual job (OR 1.4, 95% CI 1.2-1.6). Women (OR 0.05, 95% CI 0.03-0.11) and the better educated (OR 0.7, 95% CI 0.5-0.9) were significantly less likely to smoke. HIV-positive smokers had the highest risk of reporting poor health (adjusted OR compared to HIV-negative non-smokers 3.4, 95% CI 2.3-5.0). CONCLUSIONS: Smoking was significantly more common among HIV-positive than -negative employees in this predominantly male workforce. There was evidence of a combined effect on self-rated poor health, a variable shown to be a strong independent predictor of mortality in industrialised countries. Interventions to encourage smoking cessation may be an important component of HIV care in Southern Africa.

Adolescent↗
PubMed2005

HIV infection and reproductive health in teenage women orphaned and made vulnerable by AIDS in Zimbabwe.

AIDS has increased the number of orphans and vulnerable children (OVCs) in sub-Saharan Africa who could suffer detrimental life experiences. We investigated whether OVCs have heightened risks of adverse reproductive health outcomes including HIV infection. Data on HIV infection, sexually transmitted infection (STI) symptoms and pregnancy, and common risk factors were collected for OVCs and non-OVCs in a population survey of 1523 teenage children in eastern Zimbabwe between July 2001 and March 2003. Multivariate logistic regression was used to test for statistical association between OVC status, adverse reproductive health outcomes and suspected risk factors. Amongst women aged 15-18 years, OVCs had higher HIV prevalence than non-OVCs (3.2% versus 0.0%; p = 0.002) and more common experience of STI symptoms (5.9% versus 3.3%; adjusted odds ratio = 1.75, 95% CI 0.80-3.80) and teenage pregnancy (8.3% versus 1.9%; 4.25, 1.58-11.42). OVCs (overall), maternal orphans and young women with an infected parent were more likely to have received no secondary school education and to have started sex and married, which, in turn, were associated with poor reproductive health. Amongst men aged 17-18 years, OVC status was not associated with HIV infection (0.5% versus 0.0%; p = 1.000) or STI symptoms (2.7% versus 1.6%; p = 0.529). No association was found between history of medical injections and HIV risk amongst teenage women and men. High proportions of HIV infections, STIs and pregnancies among teenage girls in eastern Zimbabwe can be attributed to maternal orphanhood and parental HIV. Many of these could be averted through further female secondary school education. Predicted substantial expanded increases in orphanhood could hamper efforts to slow the acquisition of HIV infection in successive generations of young adults, perpetuating the vicious cycle of poverty and disease.

Adolescent↗
PubMed2005

Patterns of uptake of treatment for self reported sexually transmitted infection symptoms in rural Zimbabwe.

OBJECTIVES: To determine the extent of self reported symptoms perceived to be related to sexually transmitted infections and the patterns of subsequent treatment seeking behaviour in a predominantly rural population of Zimbabwe. METHODS: A population based survey of 4331 men and 5149 women was conducted in rural Zimbabwe during 1998-2000. Structured confidential interviews collected data on self reported sexually transmitted infection symptoms, treatment seeking behaviour, sociodemographic characteristics, and sexual behaviour. RESULTS: 25% of men aged 17-54 years report experiencing genital sores and 25% of men report experiencing urethral discharge; 30% of women aged 15-44 years report experiencing vaginal discharge. The lifetime number of sexual partners, age, and years of sexual activity were all significant predictors of symptoms for both men and women (all p values <0.001). 92% of men and 62% of women had sought treatment for their symptoms in the past year (p value <0.001). Men and women were equally likely to have sought treatment at a local hospital or clinic, but women were much less likely than men to have sought treatment at a different hospital or clinic. Among those who had sought treatment, men sought treatment faster than women and were more likely to report being "very satisfied" with their treatment than women. CONCLUSIONS: The gender differences in treatment seeking are of major concern for control efforts and further work on determining the reasons for these should be a priority. This would inform the likely impact of both increasing availability of local services and further reducing the stigma faced by those wishing to access such services.

Adolescent↗
PubMed2001

A rural HIV epidemic in Zimbabwe? Findings from a population-based survey.

The aim of the study was to use population-based data from 689 adults to describe the socio-demographic, behavioural and biomedical correlates of HIV infection and aid identification of effective HIV control strategies for rural Zimbabwe. Dried blood spot and urine samples were collected for HIV and sexually transmitted disease (STD) testing and participants were interviewed on socio-demographic characteristics, sexual behaviour and experience of STD symptoms. HIV seroprevalence was 23.3% and was higher in females, divorcees, widows, working men, estate residents, and respondents reporting histories of STD symptoms. Female HIV seroprevalence rises sharply at ages 16-25. A third of sexually-active adults had experienced STD-associated symptoms but there were delays in seeking treatment. Herpes simplex virus type 2 (HSV-2) and Trichomonas vaginalis are more common causes than syphilis, gonorrhoea, and chlamydia, and are strongly associated with HIV infection. Local programmes promoting safer sexual behaviour and fast and effective STD treatment among young women, divorcees and working men could reduce the extensive HIV transmission in rural communities.

Adolescent↗
PubMed2001

Enzyme immunoassay for urogenital trichomoniasis as a marker of unsafe sexual behaviour.

Enzyme immunoassay (EIA) was used to detect antibodies to Trichomonas vaginalis in sera from Zimbabwe. The EIA showed a sensitivity of 95 and 94% when compared with vaginal swab culture among women attending a family planning clinic (FPC) and female commercial sex workers (CSW) respectively. The specificity was 85 and 77% in the two groups. Culture-negative FPC women were sub-divided into high risk or low risk of exposure to trichomoniasis. The seroprevalence was 10% (6/61) among low risk women, 21% (10/48) among high risk women and 23% (9/39) among culture negative CSW. The EIA was positive in 46% (18/39) men with genital discharge but only 5% (2/37) healthy blood donors. None of 31 sera from prepubescent children was positive. The EIA may be useful for community surveys of trichomoniasis. Because T. vaginalis is a common sexually transmitted disease, the test may indicate behaviour that increases the risk of STD transmission.

Adolescent↗
PubMed2000

Value of mandatory testing for human immunodeficiency virus in a sub-Saharan hospital population.

Human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) are currently hyperendemic in sub-Saharan Africa. HIV and AIDS have a special impact on working-age populations, economic resources, certain illnesses, and health care facilities. Assessment of HIV serostatus of hospitalized patients is rarely performed, however, because of a reluctance to intrude on patient confidentiality, a perceived lack of benefit (no antiretroviral therapy is available), and societal denial. We evaluated the effect on health care of HIV testing of patients routinely admitted to medical wards in the 2 major city hospitals in Harare, Zimbabwe. Of 196 patients tested, 58% were HIV positive with strong associations with infectious diseases, and with youth and weight loss, but not with cardiac, pulmonary, endocrinologic, or renal diagnoses, and not with rural versus urban location, occupation, sex, mortality, or cost of hospitalization. The clinical estimate of patients' HIV serostatus was largely inaccurate. Mandatory HIV testing of all hospitalized patients would improve diagnosis of infectious diseases, clarify patient prognosis, allow for individual counseling with regard to HIV prevention, and focus national health efforts by providing alarming, realistic statistics.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Impact of HIV infection on meningitis in Harare, Zimbabwe: a prospective study of 406 predominantly adult patients.

OBJECTIVE: To determine the causative organisms and characteristics of patients presenting with features of meningitis. DESIGN: A prospective cross-sectional study. SETTING: Two tertiary university-affiliated hospitals in Harare, Zimbabwe. PATIENTS: Four-hundred and six patients clinically suspected to have meningitis. MAIN OUTCOME MEASURES: Causative organisms of meningitis; clinical and cerebrospinal fluid characteristics. RESULTS: Four-hundred and six predominantly adult (95% were aged > or = 18 years) patients were suspected to have meningitis. Of the 200 patients confirmed to have meningitis, 89 (45%) had cryptococcal meningitis (CM), 54 (27%) had mononuclear meningitis (MM), 31 (16%) had pyogenic meningitis (PM), 24 (12%) had tuberculous meningitis (TBM) and 2 (1%) had undefined meningitis. HIV seropositivity was 100% in CM, 83% in MM, 81% in PM and 88% in TBM patients. In-hospital mortality rate was 38.8% for CM, 34.9% for MM, 68% for PM and 66.7% for TBM. HIV seropositivity was 80% in the 206 patients not found to have meningitis. CONCLUSIONS: All patients suspected to have meningitis had a high HIV sero positivity irrespective of whether they were later confirmed to have meningitis or not. CM was the most common type of meningitis seen. In-hospital mortality was high irrespective of the cause of meningitis.

AIDS-Related Opportunistic Infections↗
PubMed2000

Effect of intravaginal practices on the vaginal and cervical mucosa of Zimbabwean women.

OBJECTIVES: Lesions on the vaginal and cervical mucosa may facilitate transmission of HIV and other sexually transmitted diseases (STDs). We evaluated the relationship between intravaginal practices and the presence of colposcopic lesions in Zimbabwean women. METHODS: Users and nonusers of intravaginal practices were seen at enrollment, and at 1 and 6 months. Interviewing, counseling, and pelvic and colposcopic examinations were performed at each study visit. Specimens were collected at enrollment and 6 months. RESULTS: Colposcopic lesions were found at least once in 83% of the participants (n = 162), and in 66% of all exams (n = 430). Most lesions were classified as related to infection with human Papillomavirus (HPV) (58%) or another pathogen (20%), but 11% of lesions could have been caused by intravaginal practices (signal lesions). Intravaginal practices were not associated with an increased incidence in signal lesions (95 and 124 lesions per 100 person-years of follow-up for users and nonusers respectively; p = .290), nor with the presence of signal lesions in multivariate baseline (odds ratio [OR], 1.32; 95% confidence interval [CI], 0.37-4.72; p = .666) and six month transition models (OR, 1.67; 95% CI, 0.59-4.70; p = .333). CONCLUSIONS: No associations between intravaginal practices and colposcopic lesions were found in this study. However, the potential effect of intravaginal practices on the cervical and vaginal mucosa, and on subsequent HIV and STD transmission, warrants further study. The usefulness of colposcopy as a research tool in areas with high prevalences of HIV and HPV is questioned.

Adolescent↗
PubMed2000

Intravaginal practices, vaginal flora disturbances, and acquisition of sexually transmitted diseases in Zimbabwean women.

One hundred sixty-nine Zimbabwean women were studied to determine whether the use of intravaginal practices (cleaning with the fingers, wiping the vagina, and inserting traditional substances) are associated with disturbances of vaginal flora and acquisition of sexually transmitted diseases (STDs). Subjects were interviewed and received counseling and a pelvic examination at enrollment, 1 month, and 6 months, and vaginal specimens were collected at enrollment and at 6 months. Users were more likely than nonusers to have vaginal flora disturbances but were not more likely to acquire an STD (relative risk [RR], 2.15; P=.188). Certain vaginal flora disturbances were associated with increased STD incidence and HIV prevalence. The absence of lactobacilli from the vaginal flora was associated with being positive for human immunodeficiency virus in baseline (odds ratio [OR], 0.24; P=.001) and 6-month transition multivariate models (OR, 0.39; P=.025). The presence of clue cells at baseline was associated with a higher incidence of STDs (RR, 1. 94; P=.025).

Adult↗
PubMed2000

Chlamydia trachomatis in symptomatic and asymptomatic men: detection in urine by enzyme immunoassay.

BACKGROUND: Infection with Chlamydia trachomatis is known to be a common cause of urethritis and cervicitis. The standard methods of detection require the collection of intra-urethral and/or cervical swabs, which may be submitted for culture, antigen detection or nucleic acid amplification. The collection of swabs is suitable only within the context of a health care facility. Recent reports have indicated that antigen detection can be used with urine specimens, and because these can be self-collected, this may be particularly useful for the detection of asymptomatic carriage. OBJECTIVE: To determine the sensitivity and specificity of urine antigen assays in the detection of chlamydial infection in men. SETTING: Two groups of men were investigated; men with urethritis attending clinics or private practitioners, and healthy adult men enrolled into either urban or rural HIV prevention projects. METHODS: Urine samples from men in both groups were collected and assayed for the presence of chlamydial antigen using a commercial enzyme immunoassay (EIA) kit. For symptomatic men an intra-urethral swab was also collected and assayed for antigen detection using a commercial EIA. For asymptomatic men, a ligase chain reaction was carried out on the same urine sample. RESULTS: The prevalence of chlamydial antigen in symptomatic men was 15% (39/257), and in asymptomatic men was 4% (15/349). The sensitivity and specificity of urine EIA for symptomatic men was 87% and 83% respectively. For asymptomatic men, the sensitivity of urine EIA was 86%, and the specificity was 100%. CONCLUSION: Urine EIA is a relatively inexpensive method for the detection of chlamydial infections in men. The true specificity in symptomatic men may be higher, as the "gold standard" that we used may give false negative results. Antigen EIA for examination of urine specimens from community surveys of asymptomatic men may be particularly useful because of the low cost of assays, and because urine samples can be self-collected without discomfort to study subjects. The prevalence of C. trachomatis that we describe here is consistent with other studies of chlamydial epidemiology in Zimbabwe.

Chlamydia Infections↗
PubMed1999

Syphilis serology and HIV infection in Harare, Zimbabwe.

OBJECTIVE: To determine the reliability of serological tests in detecting syphilis in a factory worker cohort and examine the impact of concurrent HIV infection on serological tests for syphilis. METHOD: Reactions to non-treponemal and treponemal antigens were tested using sera from a cohort of 3401 factory workers in Harare, Zimbabwe. The participants consented to regular testing for syphilis, by VDRL, and HIV using two ELISAs. All sera from men who were VDRL positive, and a random sample of VDRL negative sera, were tested by RPR, TPHA, and where appropriate FTA-Abs. From the results, men were defined as having no syphilis, active syphilis, incident syphilis, historic syphilis, or giving biological false positive reactions. RESULTS: 709 sera were examined from 580 men. There were 78 cases of active syphilis in the cohort, giving a prevalence of 2.3%, and the seroincidence was 0.25 per 100 person years of follow up. The prevalence of HIV in the cohort was 19.8%. There was a strong association between syphilis, whether active, incident or historic, and HIV seropositivity. With both HIV positive and negative sera the negative predictive values of VDRL and RPR were > 99.9% while the positive predictive value for VDRL (30%) was lower than for RPR (39%). Biological false positive reactions were detected in 0.5% of the cohort, with in most cases a transient rise in VDRL titres up to < 1/16. Higher false positive titres occurred in five men, each of whom was HIV positive. CONCLUSIONS: The VDRL is reliable in detecting possible cases of syphilis even in a community with a high prevalence of heterosexually transmitted HIV. There is need, however, for confirmatory tests. The prevalence of syphilis in this cohort is very low in comparison with other countries in southern Africa, but is consistent with recent data from Harare. Despite a strong association between syphilis and HIV it was clear that syphilis could not be counted as a major factor fueling the HIV epidemic in Zimbabwe.

Cohort Studies↗
PubMed1999

Risk factors for gonococcal and chlamydial cervical infection in pregnant and non-pregnant women in Zimbabwe.

OBJECTIVE: To identify demographic, behavioural and clinical characteristics of symptomatic and asymptomatic women with gonococcal and/or chlamydial cervicitis a study was conducted among women attending antenatal clinics and primary care clinics in Harare, Zimbabwe. DESIGN: Cross sectional study. SETTING: Primary care clinics and antenatal clinics in Harare. SUBJECTS: 467 women with vaginal discharge and 1,189 asymptomatic pregnant women. MAIN OUTCOME MEASURES: Behavioural and clinical correlates of gonococcal and chlamydial cervical infection. RESULTS: The mean age of symptomatic women was 26.11 +/- 6.84 years (range: 15 to 52 years) and that of asymptomatic pregnant women was 24.67 +/- 5.43 years (range: 15 to 45 years). Gonococcal and/or chlamydial cervical infection was found in 69 of 1,189 (5.8%) pregnant women and in 77 of 467 (16.5%) non-pregnant women. Logistic regression analysis identified the following predictors of gonococcal or chlamydial infection in women with vaginal discharge: being separated from the partner for a month or more (p = 0.002), having had sex with a new partner in the last three months (p = 0.002), current use of condoms (p = 0.011), and the finding on examination of a purulent vaginal discharge (p = 0.004). Amongst these women an increasing educational level was inversely associated with cervical infection (p = 0.007). Amongst asymptomatic pregnant women the following were identified as predictors of cervical infection: the patient admitting to having a vaginal discharge on direct questioning (p = 0.004), and the finding of a purulent vaginal discharge on examination (p = 0.001). CONCLUSIONS: Amongst symptomatic and asymptomatic women certain behavioural factors and some clinical findings are associated with cervical gonococcal or chlamydial infection. Women with multiple partners and with partners who are currently using condoms with them and those women with a purulent vaginal discharge are likely to be infected. The age and marital status of subjects was not associated with cervical infection. These findings are useful in providing appropriate care for women with overt or minimal symptoms.

Adolescent↗
PubMed1998

Pleural tuberculosis in Harare, Zimbabwe: the relationship between human immunodeficiency virus, CD4 lymphocyte count, granuloma formation and disseminated disease.

OBJECTIVE: To elucidate the relationship between HIV, CD4+ count and pleural TB. METHOD: In a prospective study, 94 patients presenting at two large Harare hospitals with clinically suspected pleural TB were enrolled over a 10-month period. All underwent standardized evaluation, closed pleural aspiration and biopsy. Patients receiving directly observed anti-TB therapy were followed-up. RESULTS: Pleural TB was diagnosed in 90 individuals (median age 33 years; range 18-65; 64 males); the seroprevalence of HIV was 85%. HIV-positive patients were older than HIV-negative individuals (median age 33 vs 23 years, P = 0.013) and had a significantly lower median CD4+ count (191 vs 1106 x 10(6)/l respectively, P = 0.004). A CD4+ count of <200 x 10(6)/l was associated with a length of illness >30 days (65% vs 37%; P = 0.05), a positive pleural fluid smear (37% vs 0%; P = 0.0006) and a positive pleural biopsy Ziehl-Neelsen stain (35% vs 7%; P = 0.021). However, a relationship between CD4+ count and either pleural granuloma formation or radiological evidence of disseminated disease was not observed. CONCLUSION: In sub-Saharan Africa, TB pleural effusions have become associated with older age, a chronic onset, and an increased mycobacterial load. These data emphasize the complex relationship between pleural TB, HIV infection and a low CD4+ count.

Adult↗
PubMed1998

Cryptococcal meningitis in human immunodeficiency virus-infected patients in Harare, Zimbabwe.

A prospective observational study was conducted over a 10-month period to determine the clinical and laboratory manifestations of cryptococcal meningitis in Zimbabwe, a country where antifungal agents are not widely available. Eighty-nine patients with cryptococcal meningitis (median age, 34 years; range, 11-63 years; 56 males) were identified from 406 patients for whom a clinical diagnosis of meningitis had been made. All patients tested were positive for antibody to human immunodeficiency virus. Cryptococcal meningitis was the first AIDS-defining illness in 88% of patients. Typical presentations were headache, mental impairment, and meningism (median duration, 14 days; range, 1-180 days). The median CD4+ cell count was 70/microL (range, 0-651/microL). The cumulative median survival from the time of diagnosis was 14 days (range, 0-233 days); 22% of patients survived for >30 days. Independent indicators of a good prognosis were not identified. This study provides a unique basis for the development of novel management strategies for patients with cryptococcal meningitis who reside in resource-poor countries.

AIDS-Related Opportunistic Infections↗
PubMed1998

Polymerase chain reaction detection of Haemophilus ducreyi DNA.

OBJECTIVES: To develop a polymerase chain reaction (PCR) method to detect Haemophilus ducreyi DNA in cultured isolates and clinical material. METHODS: Primers specific to the H ducreyi 16s rRNA gene were synthesised. PCR conditions were optimised and products were verified by restriction endonuclease digestion and agarose gel electrophoresis. RESULTS: The method was able to detect all 28 H ducreyi strains tested; specificity was demonstrated using lysates of 12 related organisms. Applied to clinical samples from genital ulcer swabs obtained in Harare, Zimbabwe, H ducreyi DNA was detected in repeated assays in 35 clinical samples. CONCLUSION: PCR amplification using primers from the 16s rRNA gene may be a useful alternative to culture for the detection of H ducreyi and the diagnosis of chancroid.

Chancroid↗
PubMed1998

Pulmonary tuberculosis in Harare, Zimbabwe: analysis by spoligotyping.

BACKGROUND: Over the last 10 years there has been a fourfold increase in cases of tuberculosis in Harare, Zimbabwe. The use of molecular epidemiology to understand tuberculosis transmission in this epidemic has been hampered by the availability of suitable culture facilities. A study was therefore undertaken to explore the potential of spoligotyping, a polymerase chain reaction based technique that does not require tuberculosis culture. METHODS: Adults attending a chest clinic with clinical or radiological pulmonary tuberculosis and one smear positive sputum were enrolled over one month. Demographic, socioeconomic, and clinical data were gathered using a standardised questionnaire. Molecular fingerprinting of genomic DNA recovered from sputum was performed by spoligotyping. RESULTS: Sixty one subjects (median age 28 years (range 18-73); 61% men) were recruited and 57 provided adequate sputum samples. Recent rural-urban migration or immigration was not common; 40% of subjects lived in crowded living conditions. DNA suitable for spoligotyping was recovered from 28 patients and 20 different genotypes of Mycobacterium tuberculosis were identified. Fifteen patients were infected with an M tuberculosis strain shared by one or more individuals. Patients infected with a shared spoligotype were not closely linked geographically within Harare, but were more likely to live in overcrowded conditions (69% versus 23%; odds ratio 6.85 (95% CI 1.2 to 47), p = 0.026). Analysis of the patients' original rural family homes revealed two geographically related spoligotype clusters. CONCLUSIONS: Spoligotyping may yield valuable molecular typing information in populations where tuberculosis culture is not available. This novel technique requires further development and evaluation in larger epidemiological studies.

Adolescent↗
PubMed1998

Spotted fever group rickettsiae in southern Africa--a review and current concepts.

Until recently our understanding of spotted fever group (SFG) rickettsioses in southern Africa was based on research carried out in the 1930s and 1940s. In the last decade there have been considerable advances in the techniques available to study rickettsias and the application of these in southern Africa has greatly increased our knowledge of the organisms in the region and the epidemiology of diseases they cause. In this review we describe the new advances used to study rickettsias and the current data available on SFG rickettsioses in the region.

Africa, Southern↗