Prevalence, pattern and factors associated with ocular disorders in small-scale welders in Katwe, Kampala.

BACKGROUND: Welders are at an increased risk of eye disorders as a result of their occupation, leading to enormous vocational and economic consequences. With limited published studies among welders in low resource settings, we sought to determine the prevalence, pattern and factors associated with ocular disorders among small-scale welders in Katwe, Kampala. METHODS: In a field-based cross-sectional study, we recruited 343 small-scale welders. Simple random sampling was done to select the study participants. A pretested questionnaire was used to collect information on demographics, ocular, general history, systemic and ocular examination. The proportion of small-scale welders with ocular disorders (defined as any abnormal finding on eye examination) was determined. The bivariate and multivariate analyses were carried out, using logistic regression methods at a level of significance of 0.05. RESULTS: The mean age of the participants was 36 years (SD ± 12). The overall prevalence of ocular disorders was found to be 59.9%. The common ocular disorders included conjunctiva disorders (32%) and presbyopia (27%). There was a statistically significant relationship between females (OR = 4.279, P-value = 0.007), age 35 and above (OR = 4.244, P-value< 0.001), history of foreign body removal (OR = 1.677, P-value = 0.041), and ocular disorders. CONCLUSIONS: There is a high prevalence of ocular disorders among small-scale welders. Conjunctiva disorders, presbyopia and myopia were the commonest. Being female, age 35 and above and foreign body removal, were significantly associated with ocular disorders among welders. Policies should be put in place to ensure all welders use proper personal -protective equipment (welding helmets), and also receive regular eye checkup and health education.

Human papillomavirus infection and squamous cell carcinoma of the conjunctiva.

BACKGROUND: Squamous cell carcinoma of the conjunctiva (SCCC) is associated with HIV-related immunosuppression, but human papillomavirus virus (HPV) is also suspected to have a role. We carried out a case-control study to assess the role of cutaneous and mucosal HPV types in SCCC, conjunctival dysplasia, and their combination (SCCC/dysplasia) in Uganda. METHODS: We compared HPV prevalence in frozen biopsies from 94 SCCC cases (79 of whom were found to be HIV-positive), 39 dysplasia cases (34 HIV-positive), and 285 hospital controls (128 HIV-positive) having other eye conditions that required surgery. Highly sensitive PCR assays that detect 75 HPV types were used. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed, adjusting for, or stratifying by age, sex, and HIV status. RESULTS: Cutaneous HPV types were detected in 45% of SCCC cases, 41% of dysplasia cases and 11% of controls. Human papillomavirus virus 5 and 8 were the most common types in SCCC, and most often occurred in combination with other types. Associations were observed between SCCC/dysplasia and detection of both single (OR=2.3; 1.2-4.4) and multiple (OR=18.3; 6.2-54.4) cutaneous HPV types, and were chiefly based on findings in HIV-positive patients. Cutaneous HPV infections were rarely observed among HIV-negative patients and the association with SCCC/dysplasia was not significant (OR=2.4; 0.6-9.6) among them. Squamous cell carcinoma of the conjunctiva/dysplasia risk and mucosal HPV types were not associated in either HIV-positive or HIV-negative patients. CONCLUSIONS: We detected cutaneous HPV types in nearly half of SCCC/dysplasia cases and often multiple types (HPV5 and 8 being most common). The role of HIV (confounder or strong enhancer of cutaneous HPV carcinogenicity) is still uncertain.

Conjunctival squamous-cell carcinoma associated with HIV infection in Kampala, Uganda.

The incidence of conjunctival squamous-cell carcinoma in Kampala, Uganda, was steady at around 6 per million per year from 1970 until 1988, but has increased six-fold since then to 35 per million per year in 1992. Among 48 patients with conjunctival tumours seen at the ophthalmology clinic of the New Mulago Hospital from 1990 to 1991, 75% were HIV seropositive, compared with a 19% seropositivity rate among 48 matched controls (relative risk 13.0, 95% CI 4.5-39.4, p < 0.0001). The recent epidemic of conjunctival tumours in Uganda (and in neighbouring countries) appears to be largely due to the epidemic of HIV infection. Other factors that may contribute to the high incidence of these tumours in equatorial Africa may be exposure to ultraviolet light and conjunctival papillomavirus infection.

PIP: The incidence of conjunctival squamous-cell carcinoma in Kampala, Uganda, was 6/million/year from 1970 until 1988, and it has increased to 35/million/year in 1992. Between February 1990 and February 1991, HIV tests were performed on all 48 patients who presented with conjunctival squamous cell carcinoma of the eye. A comparison was made with matched controls suffering from other eye diseases. 36 (75%) of the cancer patients were seropositive as compared with 9 (19%) of the controls. The cancerous tumors started as a whitish swelling in the limbus and rapidly increased in size. This study showed a relative risk for conjunctival tumors associated with HIV infection of 13:0. It appears from the scarcity of reports that these tumors are uncommon in HIV-infected subjects in the US and Europe. This would reflect the fact that before the AIDS epidemic, these tumors were more common in equatorial Africa than elsewhere, leading to the possibility that the combination of HIV-induced immunosuppression, conjunctival papilloma virus infections, and intense exposure to ultraviolet light may hasten the development of these tumors.

Epidermodysplasia verruciformis human papillomavirus types and carcinoma of the conjunctiva: a pilot study.

A total of 21 squamous-cell carcinoma of the conjunctiva (SCC) and 22 control subjects had conjunctival samples tested for human papillomavirus (HPV) types using PCR-based assays. Epidermodysplasia verruciformis HPV types were found in 86% of SCC cases and 36% of control subjects (Odds ratio=12.0), suggesting a role of HPVs in the aetiology of SCC.

The epidemiology of conjunctival squamous cell carcinoma in Uganda.

As part of a larger investigation of cancer in Uganda, we conducted a case-control study of conjunctival squamous cell carcinoma in adults presenting at hospitals in Kampala. Participants were interviewed about social and lifestyle factors and had blood tested for antibodies to HIV, KSHV and HPV-16, -18 and -45. The odds of each factor among 60 people with conjunctival cancer was compared to that among 1214 controls with other cancer sites or types, using odds ratios, estimated with unconditional logistic regression. Conjunctival cancer was associated with HIV infection (OR 10.1, 95% confidence intervals [CI] 5.2-19.4; P<0.001), and was less common in those with a higher personal income (OR=0.4, 95% CI 0.3-0.7; P<0.001)[corrected]. The risk of conjunctival cancer increased with increasing time spent in cultivation and therefore in direct sunlight (chi2 trend=3.9, P=0.05), but decreased with decreasing age at leaving home (chi2 trend=3.9, P=0.05), perhaps reflecting less exposure to sunlight consequent to working in towns, although both results were of borderline statistical significance. To reduce confounding, sexual and reproductive variables were examined among HIV seropositive individuals only. Cases were more likely than controls to report that they had given or received gifts for sex (OR 3.5, 95% CI 1.2-10.4; P=0.03), but this may have been a chance finding as no other sexual or reproductive variable was associated with conjunctival cancer, including the number of self-reported lifetime sexual partners (P=0.4). The seroprevalence of antibodies against HPV-18 and -45 was too low to make reliable conclusions. The presence of anti-HPV-16 antibodies was not significantly associated with squamous cell carcinoma of the conjunctiva (OR 1.5, 95% CI 0.5-4.3; P=0.5) and nor were anti-KSHV antibodies (OR 0.9, 95% CI 0.4-2.1; P=0.8). The 10-fold increased risk of conjunctival cancer in HIV infected individuals is similar to results from other studies. The role of other oncogenic viral infections is unclear.