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D C Mabey

Publications and source records attributed to D C Mabey.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Trachoma in the Sabou area (Burkina Faso). An epidemiological investigation].

Little is known about the epidemiology of trachoma in the Mossi plateau of Burkina Faso and the recent drought could have modified the transmission of the disease. A study population of 82,187 was surveyed using a cluster sample technique. A total of 1,841 people in 108 compounds were included in 18 villages. Data concerning trachoma were collected during six weeks of fieldwork in July 1991, during which local health workers were trained in trachoma and primary health care in ophthalmology. Active trachoma prevalence rises in infancy to reach a peak of about 13% (95% CI 3-23) in the 2 to 5 years old age groups, and then falls to less than 2% prevalence in 30 to 49 age group. Trachoma scarring is almost non-existent and trichiasis was not seen. Active disease was significantly more prevalent in female (prevalence ratio = 1.97, 95% CI: 1.34-2.90) and this difference was present from the age of 3 years. Active trachoma above the age of 30 was more likely to be intense than follicular (p < 0.001, Fisher's exact test). Because of a low prevalence of active disease and because trichiasis is absent, trachoma is not a major health problem in the Sabou area, Burkina Faso. Girls are more affected by active disease than boys and inflammatory trachoma in adults are usually intense in this setting.

Adolescent↗
PubMed1991

The impact of medical services on trachoma in a Gambian village: antibiotics alone are not the answer.

We have measured the prevalence of active trachoma in children aged less than 15 years in the Gambian village of Keneba, which has had excellent free medical care and a continuous supply of antibiotics since 1974. The prevalence was 13%, with the peak prevalence (20%) occurring in the 2 to 3-year age group. Of 71 cases diagnosed, only 23 (33%) had complained of ocular symptoms in the previous 3 months, in spite of the fact that 66 (94%) had attended the clinic. Only five had been diagnosed as having trachoma by the duty paediatrician (7%). Compliance with treatment was poor, with only 29 subjects returning for continued treatment (41%), and at follow-up 16 months later 22 of 64 subjects still had active disease (34%). We conclude that the widespread use of antimicrobial agents does not preclude the persistence of endemic disease. Socio-economic improvement or behavioural changes appear necessary for the control of trachoma in endemic areas. In the meantime there is a need for greater awareness of the disease both among clinicians in endemic areas and among the communities afflicted.

Adolescent↗
PubMed1991

Lymphocyte proliferative responses to chlamydial antigens in human chlamydial eye infections.

In order to study the relationship between cell-mediated immune responses to Chlamydia trachomatis and the pathogenesis of human chlamydial eye disease, we have measured the peripheral blood lymphocyte proliferative responses to whole chlamydial elementary bodies in 40 subjects with oculogenital chlamydial infection of varying severity, 13 subjects with genital chlamydial infections and 12 healthy seronegative controls. The mean stimulation index was significantly higher in those with oculogenital infections than in controls. There was a strong correlation between the response to C. trachomatis serotypes B and L1. We studied the relationship between proliferative responses and four clinical parameters: follicular conjunctivitis, papillary hypertrophy, corneal pannus and epithelial punctate keratitis, but were unable to show a significant association with any of these. Nor was there any association between proliferative response and serum antibody titre to C. trachomatis (pooled serotypes D-K), duration of disease or quantitative isolation of chlamydia from the conjunctiva. The depletion of CD8+ cells had no consistent effect on proliferative responses to serotype L1 in 13 subjects.

CD8 Antigens↗
PubMed1991

Expression of MHC class II antigens by conjunctival epithelial cells in trachoma: implications concerning the pathogenesis of blinding disease.

In an attempt to understand the pathogenesis of corneal changes and conjunctival scarring in trachoma, which are responsible for blindness in some 7 million people worldwide, the surface expression of major histocompatibility complex class II antigens on conjunctival epithelial cells was sought in patients with different clinical features of the disease. Class II expression was significantly associated with active (inflammatory) trachoma, but an independent association with corneal pannus or conjunctival scarring could not be shown. Longitudinal data suggest that class II expression may antedate clinically active disease and persist after it has resolved.

Adolescent↗
PubMed1991

A typhus-like illness caused by acute HIV seroconversion.

A patient is described in whom an acute human immunodeficiency virus seroconversion illness occurred following a trip to southern Africa. The presentation was strikingly similar to that of African tick typhus and could only be distinguished by serological testing.

Adult↗
PubMed1989

Analysis of the household distribution of trachoma in a Gambian village using a Monte Carlo simulation procedure.

Studies on the household distribution of trachoma have reached conflicting conclusions. This paper describes a cross-sectional survey of endemic trachoma in a Gambian village. Cases of active trachoma were mapped, and the compound and household distribution of the disease analysed by a Monte Carlo simulation procedure which takes into account differences in the size and age distribution within individual households. Significant clustering of active trachoma cases both by village compound (p less than 0.0001) and bedroom (less than 0.05) were detected supporting the concept that intra-familial transmission of trachoma is important. There was no evidence of spatial clustering of rooms with higher than expected prevalence of trachoma. Clustering of disease in space or time provides important evidence of infectious aetiology and route of transmission. The methods discussed here are generally applicable in the study of other infectious diseases.

Adolescent↗
PubMed1988

Human retroviral infections in The Gambia: prevalence and clinical features.

The prevalence of infection with human immunodeficiency virus type 1 (HIV 1) is lower in west Africa than in other parts of Africa. Human immunodeficiency virus type 2 (HIV 2) has been isolated from west African patients and may be transmitted by heterosexual contact. The prevalence of antibodies to HIV 1 and HIV 2 was studied by enzyme linked immunosorbent assay (ELISA) among various groups of subjects in The Gambia, west Africa--namely, prostitutes, blood donors, patients with suspected infection with HIV, patients attending clinics for sexually transmitted diseases, and patients with tuberculosis. Four cases of the acquired immune deficiency syndrome (AIDS) due to infection with HIV 1 were detected, of which three had been acquired abroad. No other subject was found to be positive for antibodies to HIV 1. The prevalence of antibodies to HIV 2 among the patients attending clinics for sexually transmitted diseases was found to have increased from 0/117 in 1984 to 10/185 (5%) in the last six months of 1986. One out of 278 blood donors was positive for antibodies to HIV 2 as were 10 out of 80 patients with suspected AIDS. HIV 2 seems to be transmitted sexually, and, although it has been present for only a short time, it seems to be endemic in The Gambia and is pathogenic.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Detection of Chlamydia trachomatis by enzyme immunoassay in patients with trachoma.

Trachoma control necessitates identification of individuals shedding ocular chlamydiae. Conventional techniques of chlamydial culture are unsuitable for large field surveys in developing countries. In this study an enzyme immunoassay (EIA) developed for the detection of chlamydial antigen in genital-tract infection was used in trachoma. Conjunctival swabs were taken for chlamydial antigen detection from 1225 subjects in a Gambian village with endemic trachoma. Of these, 997 had insignificant or no disease and 172 had mild, 30 moderate, and 26 severe disease. Chlamydial antigen was detected in 5.0%, 20.3%, 46.7%, and 26.9% of subjects in these four categories, respectively. Samples for chlamydial isolation were obtained from 259 subjects. The corresponding rates of detection obtained by chlamydial isolation were 3/90 (3.3%), 16/129 (12.4%), 7/21 (33.3%), and 7/19 (36.8%). If isolation is taken as the "gold standard", the EIA technique had a sensitivity of 70.6% and a specificity of 90%. A substantial proportion of subjects with severe conjunctival scarring, from whom chlamydiae cannot generally be isolated, were antigen positive by EIA, implying that persistent chlamydial antigen plays a part in the pathogenesis of the late sequelae of trachoma.

Antigens, Bacterial↗
PubMed1987

Plasmid content, auxotype and protein-I serovar of gonococci isolated in the Gambia.

Twenty-nine strains of penicillinase-producing Neisseria gonorrhoeae (PPNG) and 30 non-penicillinase-producing strains, all isolated in the Gambia, were characterized in terms of their plasmid content, auxotype and protein-I serovar. Sixty-two per cent of the PPNG strains contained the 3.2 MDa penicillinase-coding plasmid, and 38% had the 4.4 MDa plasmid. All the PPNG strains contained the 2.6 MDa cryptic plasmid but lacked the 24.4 MDa conjugative plasmid. In contrast, 46.7% of the non-PPNG strains harboured only the cryptic plasmid while 16.7% contained both the cryptic and conjugative plasmids. Seventeen per cent of the non-PPNG strains contained the conjugative plasmid only and 20% lacked plasmids. The PPNG and non-PPNG strains also differed in terms of their protein-I serovar. Eighty-six per cent of the PPNG strains belonged to serogroup 1 A, whereas the majority (60%) of non-PPNG strains belonged to serogroup 1 B. There was no significant difference in the auxotypes of the PPNG and non-PPNG strains, with both groups consisting predominantly of prototrophic and proline-requiring strains, with a minority of strains requiring arginine. When the 59 strains were each characterized in terms of their combined plasmid profile, auxotype and serovar, 39 different combinations were noted, which indicates the heterogeneous nature of the gonococcal population found in the Gambia.

Gambia↗
PubMed1987

Aetiology of genital ulceration in the Gambia.

The aetiology of genital ulceration was studied in 104 unselected patients (94 men, 10 women) attending a sexually transmitted disease (STD) clinic in the Gambia. Chancroid was diagnosed in 54 (52%), syphilis in 23 (22%), lymphogranuloma venereum (LGV) in seven (7%), and herpes in six (6%). In 28 (27%) patients no diagnosis was reached. Ten (10%) patients were found to have both chancroid and syphilis, three (3%) had both LGV and syphilis, and one (1%) had both herpes and syphilis. Trimethoprim 160 mg and sulphamethoxazole 800 mg twice daily for one week was found to be effective in the treatment of chancroid. This regimen with a single intramuscular injection of benzathine penicillin 2.4 MIU is recommended for the treatment of genital ulcers in Gambian health centres without laboratory facilities.

Adolescent↗