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Biomedical subjects

D Mabey

Publications and source records attributed to D Mabey.

At least 73 records · Page 4Linked to original sources
PubMed1997

STD rapid assessment in Rwandan refugee camps in Tanzania.

OBJECTIVE: To obtain baseline information on sexually transmitted diseases (STDs) in the Rwandan refugees camps in Tanzania, prior to establishment of STD services. SETTING: The largest camps of Rwandan refugees in the Ngara District of Tanzania (estimated population 300,000). The study was carried out in 8 days in August 1994. SUBJECTS AND METHODS: A rapid assessment technique was used to measure STD prevalences among: (i) 100 antenatal clinic attenders (ANC); (ii) 239 men from outpatient clinics (OPD); and (iii) 289 men from the community. Interviews (by questionnaire) and genital examination were performed for all participants; sampling for females included genital swabs for the the diagnosis of Neisseria gonorrhoeae (NG), Candida albicans (CA), Trichomonas vaginalis (TV), bacterial vaginosis (BV) and a blood sample for syphilis serology. Men provided urine samples which were screened for leucocytes using the leucocyte esterase (LE) dipstick; urethral swabs for Gram stain were taken from men with a reactive LE test and from those with symptoms or signs of urethritis. OPD males provided a blood sample for syphilis serology. RESULTS: All groups reported frequent experience with STDs and engaging in risky sexual behaviour prior to the survey. During the establishment of the camps, sexual activity was reportedly low. Over 50% of ANC attenders were infected with agents causing vaginitis (TV/BV/CA) and 3% were infected with NG. The prevalence of active syphilis was 4%. In the male outpatients, the prevalence of urethritis was 2.6% and of serological syphilis was 6.1%. Among males in the community, the prevalence of urethritis was 2.9% (the majority being asymptomatic infections). We noted frequent over-reporting of STD symptoms, unconfirmed clinically or biologically. CONCLUSIONS: STD case detection and management should be improved by training health workers in using the WHO syndromic approach, and through IEC campaigns encouraging attendance at clinics. Rapid epidemiological methods provide quick and useful information at low cost in refugee camps.

Adolescent↗
PubMed1997

Randomised trials of STD treatment for HIV prevention: report of an international workshop. HIV/STD Trials Workshop Group.

Three community trials of the impact of STD treatment interventions on HIV incidence in rural populations have been completed or are in progress in Uganda and Tanzania. Investigators from these trials met for a joint technical workshop in Baltimore in May 1996. This report summarises the consensus of the workshop, with the aim of providing useful input to research on HIV intervention strategies. Issues discussed include: (i) the role of community randomised trials; (ii) strategies for STD management; (iii) epidemiological and statistical issues in the design and analysis of community randomised trials; (iv) diagnostic methods for STDs in population surveys; (v) treatment regimens for STDs in rural Africa; and (vi) ethical issues in community trials.

Community Health Services↗
PubMed1997

Blindness and low vision in Jimma Zone, Ethopia: results of a population-based survey.

A population-based study on the prevalence of blindness and low vision was carried out in Jimma Zone, south-western Ethiopia between November 1994 and January 1995. A total of 7423 people from a sample of 8215 (90.4%) was examined. Sixty-three (0.85%) were blind (visual acuity less than 3/60 in the better eye) and 125 people (1.7%) had low vision (less than 6/18-3/60). Cataract and aphakia (52.4%), corneal opacity and phthisis bulbi (25.4%), and glaucoma (9.5%) were the major causes of blindness. Cataract (56.8%), refractive errors (28.8%), and corneal opacity (12.8%) were the major causes of low vision. Corneal opacity from trachoma was responsible for 20.6% of all blindness and 10.4% of low vision. The prevalence of visual impairment due to refractive errors was 5.1/1000 population. Almost 25% of the study population had active trachoma, and 0.9% of pre-school children had signs of vitamin A deficiency. Out of a total population of 2 million an estimated 17,000 people are blind and 34,000 have low vision (i.e., a total of 51,000 people with visual impairment). Approximately 20,000 people require cataract surgery, 52,000 require lid surgery for trichiasis, 24,000 require spectacles (excluding presbyopia), including 10,000 for significant refractive errors, half a million require treatment for active trachoma and 4,000 require glaucoma treatment. Effective and feasible eye care programs need to be established in the zone and the available ophthalmic services have to be strengthened. These may be achievable through joint efforts of the community and the Ministry of Health in collaboration with non-governmental organizations. The available eye services are briefly described and recommendations made to meet the important needs for prevention of blindness in the region.

Adolescent↗
PubMed1997

Increasing prevalence of penicillinase-producing Neisseria gonorrhoeae and the emergence of high-level, plasmid-mediated tetracycline resistance among gonococcal isolates in The Gambia.

One hundred and three strains of Neisseria gonorrhoeae isolated from a periurban STD clinic in The Gambia were studied for antimicrobial susceptibility, plasmid profile, and serogroup using standard procedures. Seventy-nine (77%) were penicillinase producers (PPNG) and fully resistant to penicillin (MIC > or = 8 mg/l). One isolate showed chromosomally induced resistance to penicillin (MIC 2 mg/l). None of the isolates was sensitive to tetracycline; 16 (16%) showed intermediate resistance (MICs 1-8 mg/l) and 87 (84%) showed high-level plasmid-mediated resistance (TRNG) (MICs > 10 mg/l). This is the first report of TRNG in The Gambia. Only 6 (6%) strains were fully sensitive to trimethoprim-sulphamethoxazole (MIC < 8 mg/l); 78 (76%) showed intermediate level resistance (MICs 8-16 mg/l) and 19 (18%) were fully resistant (MIC > 32 mg/l). Indications of an increase in MIC to ciprofloxacin and ceftriaxone were found in 6 (6%) and 1 (1%) strains, respectively, although all remained fully sensitive (MICs 0.004-0.03 mg/l and 0.001-0.015 mg/l). All PPNG and TRNG strains carried the 3.2 MDa and 25.2 MDa plasmids, respectively. All isolates carried the 2.6 MDa cryptic plasmid and 9 (3 PPNG and 6 non-PPNG) carried the 24.5 MDa conjugative plasmid. Forty-four (43%) strains were typed group W1, 58 (56%) W11/111 and 1 had cross-reacting antigens. Because PPNG are frequently encountered and high-level TRNG is now prevalent, the newer cephalosporins and quinolones must now be considered as first-line drugs for the treatment of gonorrhoea in The Gambia.

Anti-Bacterial Agents↗
PubMed1996

The effects of multiple doses of ivermectin on ocular onchocerciasis. A six-year follow-up.

BACKGROUND: Ivermectin has been shown to be a safe treatment for onchocerciasis and is now being distributed through mass treatment programs. Previous studies of up to 3 years of treatment have demonstrated that ivermectin improves anterior segment lesions and reduces the incidence of optic atrophy. The benefit of multiple doses of ivermectin on visual acuity and chorioretinitis has yet to be shown. METHODS: A community-based, double-blind, randomized, controlled trial of ivermectin was started in Bo, Sierra Leone, in 1987. Two cohorts are reported in this study: (1) 214 subjects had received four 6-month doses of ivermectin followed by up to six additional 6-month treatments. The second cohort, with 185 subjects, had received four 6-month doses of placebo followed by up to four annual doses of ivermectin. All subjects received a full ophthalmic examination in 1989 and again in 1994. For both cohorts, there was an 18-month gap between the fifth and sixth rounds of treatment. RESULTS: There was no significant difference in the prevalences of any ocular lesion nor of visual acuity categories between the cohorts at the second examination. Comparisons of the prevalences of anterior segment lesions for both cohorts combined between the first and second examinations show highly significant improvement (P < 0.001) for all lesions. Posterior segment lesions show a more variable pattern, with chorioretinitis showing highly significant deterioration (P < 0.001) and the emergence of new lesions in both groups. CONCLUSION: The authors conclude that annual treatment with ivermectin is effective in controlling ocular onchocerciasis apart from chorioretinal lesions and that a 6-month treatment gives no additional benefit.

Adult↗
PubMed1995

Tropical medicine for the 21st century.

The specialty of tropical medicine originated from the needs of the colonial era and is removed from many of the health care requirements of tropical countries today. Tropical medicine concentrates on parasitic diseases of warm climates, although other infections and diseases related to poverty rather than climate dominate medicine in developing countries challenged by population pressure, civil strife, and migration. In the new century, tropical medicine would best be absorbed into the specialty of infectious diseases, which should incorporate parasitic diseases, travel medicine, and sexually transmitted diseases. Pressing questions for health care and research in developing countries concern the provision of appropriate services for problems such as HIV/AIDS, tuberculosis, sexually transmitted diseases, and injuries. The question of how to provide appropriate clinical care in resource poor settings for the major causes of morbidity and premature mortality has been neglected by donors, academic institutions, and traditional tropical medicine.

Forecasting↗
PubMed1995

A community trial of the impact of improved sexually transmitted disease treatment on the HIV epidemic in rural Tanzania: 1. Design.

OBJECTIVE: To describe the rationale and design of a randomized trial of the impact of improved services for the treatment of sexually transmitted diseases (STD) on the incidence of HIV infection in Mwanza Region, Tanzania. METHODS: The likely impact of improved STD treatment services on HIV incidence, and the need for empirical information on the effectiveness of this intervention strategy, are discussed. The rationale and design of such an intervention programme in Mwanza Region, and of a community-randomized trial to measure the impact of the programme on HIV and other STD, are presented. Problems in the design and interpretation of the trial are reviewed. RESULTS: Results of the baseline survey of the cohort of over 12,000 adults in 12 communities are presented in a companion paper. CONCLUSION: There is an urgent need for effective preventive measures against the HIV epidemic in sub-Saharan Africa and other developing regions. Improved STD treatment has been promoted as a potentially effective strategy, but there is little empirical information on its impact. The trial in Mwanza Region is the first randomized study of this intervention and should provide valuable data for health policy makers.

Adult↗
PubMed1995

Simplified PCR for detection of Haemophilus ducreyi and diagnosis of chancroid.

A simplified PCR was developed for detection of Haemophilus ducreyi in samples from chancroid patients. The strategy included a straightforward chloroform extraction sample preparation method, a one-tube nested PCR to minimize contamination risks, and a colorimetric method for detection of products. Primers were designed from published nucleotide sequences of the 16S rRNA gene of H. ducreyi, with longer outer primers for annealing at a higher temperature and shorter inner primers labelled with biotin and digoxigenin for binding with avidin and colorimetric detection. The PCR technique detected all 35 strains of H. ducreyi tested, from four different geographical regions, and was negative for other, related strains of bacteria and for the common contaminating bacteria tested. Of 25 samples from H. ducreyi culture-positive chancroid patients, 24 were PCR positive and 1 produced a weak reaction. Of 83 samples from clinical cases of chancroid in the Republic of South Africa, 69 were PCR positive. The sensitivity of PCR compared with that of clinical diagnosis was 83%. All 50 negative control samples were negative. Encouraging results were also obtained with a consecutive series of 25 genital ulcer patients in Tanzania, of whom 9 were PCR positive. The adaptations of this simplified PCR strategy, at the sensitivity and specificity levels obtained, mean it will be useful for detection of H. ducreyi in areas where the organism is endemic, particularly where testing by culture is difficult or impossible.

Base Sequence↗
PubMed1995

Antimicrobial susceptibility, auxotype and plasmid content of Neisseria gonorrhoeae in northern Tanzania: emergence of high level plasmid mediated tetracycline resistance.

OBJECTIVE: To study the antimicrobial susceptibility, plasmid content, auxotype and serogroup of strains of Neisseria gonorrhoeae isolated from an urban population of STD clinic attenders in Northern Tanzania. METHODS: The minimum inhibitory concentrations of nine common antimicrobial agents were measured by the agar dilution method against 130 strains of Neisseria gonorrhoeae isolated in a free government STD clinic in Mwanza town. The auxotype, plasmid content and serogroup of these strains were also determined by conventional techniques. RESULTS: 65 strains (50%) were penicillinase producers (PPNG), and 34 (26%) exhibited chromosomally mediated resistance to penicillin. Seven (5%) were sensitive to tetracycline; 78 (60%) showed intermediate levels of resistance, and 45 (35%) had high level plasmid mediated resistance (TRNG), all of which carried a 25.2 MDa plasmid. 79 strains (61%) showed decreased sensitivity to trimethoprim-sulphamethoxazole, and five (4%) were resistant to this agent. All isolates were fully sensitive to spectinomycin, azithromycin, cefotaxime, cefuroxime, norfloxacin and ciprofloxacin. One hundred and one strains (78%) were of type W11/111, 22 type W1, and seven cross reacting strains. The W1 strains were significantly more likely to be carrying plasmid mediated resistance to both penicillin and tetracycline. Six different auxotypes were present, the major type requiring proline. Plasmid profiles showed the presence of both the 3.2 MDa and the 4.4 MDa beta-lactamase encoding plasmids. CONCLUSION: a high proportion of gonococcal isolates remain resistant to penicillin in this region, and most isolates are now also resistant to tetracycline, with the emergence of plasmic mediated tetracycline resistance. Trimethoprim-sulphonamide sensitivity is also decreasing. The population of strains is heterogeneous, and both African and Asian beta-lactamase encoding plasmids are present.

Animals↗
PubMed1995

Asymptomatic carriage of Haemophilus ducreyi confirmed by the polymerase chain reaction.

OBJECTIVE: To investigate asymptomatic carriage of Haemophilus ducreyi by using polymerase chain reaction (PCR) on samples from women at high risk of infection. SUBJECTS: 213 commercial sex workers (CSWs) recruited in The Gambia, West Africa. METHODS: Genital samples (cervical, vaginal and ulcer) were tested for the presence of H ducreyi by PCR with the technique of "one tube nested primer". RESULTS: 12 CSWs were PCR positive for H ducreyi; 8 of these women had genital ulcers on examination. CONCLUSION: Using a simplified PCR technique for detecting H ducreyi we have shown that 2% of CSWs were carrying the organism without clinical symptoms or signs. This has important implications for sexually transmitted disease control programmes in areas with a high prevalence of chancroid.

Base Sequence↗
PubMed1994

Risk behaviour and HIV prevalence in international travellers.

OBJECTIVE: To assess risk factors for infection and to determine HIV prevalence in a sample of international travellers. DESIGN: A cross-sectional survey of new patients attending a hospital outpatient clinic, and self-completion of an anonymous questionnaire on sexual behaviour prior to and during travel. Urine samples were tested for the presence of antibodies to HIV. SETTING: The Hospital for Tropical Diseases, London, UK. SUBJECTS: All new patients over a 6-month period. RESULTS: Of 782 people approached, 757 (97%) agreed to participate: 141 (18.6%) had had new sexual partners during their most recent trip abroad. Almost two-thirds of those having sex abroad did not use condoms on every occasion with a new partner, and 5.7% contracted a sexually transmitted disease (STD) during their most recent trip; 26% of men from World Health Organization Pattern I countries who had new sexual partners abroad paid for sex. Sixteen out of 731 (2.2%) participants were HIV-antibody-positive. HIV positivity was associated with being born in east, central or southern Africa, having symptoms of an STD since arriving in the United Kingdom and being treated for an STD since arrival. CONCLUSION: The rates of unsafe sex and payment for sex abroad reported by these international travellers indicate the potential for contracting and transmitting STD, including HIV, in both their foreign and domestic sexual partnerships. With the increasing HIV incidence in Asia (the most common destination for UK travellers after sub-Saharan Africa), the number of cases of HIV contracted abroad may rise in the future.

Adult↗