5 research outputs found
External Ocular Surface Bacterial Isolates and their Antimicrobial Susceptibility Patterns among Pre-operative Cataract Patients at Mulago National Hospital in Kampala, Uganda.
Endophthalmitis is a severe complication of cataract surgery which leads to high ocular morbidity and visual loss even with antibiotic treatment. Bacterial ocular floras are the implicated causative agents. This study was undertaken to evaluate the external ocular surface bacterial isolates and their antimicrobial susceptibility patterns among pre-operative cataract patients at Mulago National Hospital. This cross sectional study enrolled consecutively 131 patients scheduled for routine cataract surgery in the Department of Ophthalmology at Mulago National Hospital in Kampala, Uganda. Eyelid margin and conjunctival swabs were collected and processed using standard microbiological procedures to identify bacterial isolates and their respective antimicrobial susceptibility patterns. Of 131 patients involved (mean age 63.3 ± 14.5 years), 54.2% (71/131) were females. The eyelid margin and conjunctival samples were culture positive in 59.5% (78/138) and 45.8% (60/138) respectively. The most common organisms identified were Coagulase-negative Staphylococci (CoNS) [65.9% (91/138)] and Staphylococcus aureus [21.0% (29/138)]. CoNS showed the highest resistance to tetracycline (58.2%, 53/91) and erythromycin (38.5%, 35/91), whereas in S. aureus the resistance to tetracycline and erythromycin were 55.2% (16/29) and 31.0% (9/29) respectively. Methicillin resistant CoNS (MRS) and Methicillin resistance S. aureus (MRSA) were 31.9% (29/91) and 27.6% (8/29) respectively. There were low resistance rates for CoNS, S. aureus and other bacterial isolates to ciprofloxacin (11.1%-24.2%), gentamicin (5.6-31.0%), tobramycin (17.2% -25.3%) and vancomycin (0.0%). CoNS and S. aureus are the most common bacterial isolates found on the external ocular surface of the pre-operative cataract patients. Ciprofloxacin, gentamicin, tobramycin and vancomycin showed the lowest resistance rates to all bacterial isolates, therefore may be used to reduce bacteria load in the conjunctiva sac among cataract patients prior to surgery
Human papillomaviruses and their association with squamous cell carcinoma of the conjunctiva
Squamous cell carcinoma of the conjunctiva (SCCC), hitherto a rare
cancer, has increased manyfold since the advent of HIV/AIDS. Solar ultra
violet radiation (UV) may also be a risk factor for the disease. The
increased incidence has led to the hypothesis of an infective agent as a
risk factor, especially infections with human papillomaviruses (HPV)
types 16 and 18. The main purpose of this thesis was to study the
association between these factors and SCCC.
Pilot studies I and II. Aims: to assess the feasibility and test methods
for a larger case control study in Uganda; to investigate the presence of
HPV in conjunctival tissue using broad spectrum PCR; to investigate the
presence of UV induced mutations in the TP53 gene in SCCC samples.
Methods: 21 SCCC cases and 22 control patients were tested for the
presence of HPV in conjunctival tissue; the DNA from the samples was
further analyzed for the presence of somatic mutations in the T53 gene.
Results: Cutaneous HPV were found in 86% cases and 36% controls,
suggesting a role of cutaneous HPV in the aetiology of SCCC. Seven of the
mutations were CC to TT transitions, which are characteristic of solar UV
light DNA damage.
Study III. Aims: to assess the presence of HPV in lesion-free conjunctiva
and assess whether there is an excess of HPV infection in concurrent
HIV/AIDS disease. Methods: 136 lesion-free frozen conjunctival samples
from autopsies performed at Mulago hospital, Kampala, Uganda, were
analyzed for the presence of HPV using broad spectrum PCR methods.
Results: 14.6% samples tested positive for cutaneous HPV, and no mucosal
HPV infection was detected; no excess of HPV infection was found in
individuals who had died of HIV/AIDS-related causes as compared to those
who had died of other diseases. Conclusion: HPV infection occurs in the
conjunctiva: there was no excess of HPV infection in HIV/AIDS patients as
compared to other patients, though we cannot rule out the possibility of
the misclassification of HIV/AIDS patients.
Study IV. Aims: to compare the prevalence of HPV infection in SCCC
patients patients with other eye diseases. Methods: Hospital-based case
control study in Mulago and Jinja Hospitals, Uganda, involving 94 cases
of SCCC and 285 controls with other eye diseases. We compared the
prevalence of HPV infection in 94 biopsies of SCCC patients to 285
biopsies from hospital control patients with other eye diseases. Highly
sensitive broad spectrum PCR tests that detect up to 75 types of HPV were
used to analyze the frozen tissue biopsies. Adjusted odds ratios (OR) and
95% confidence intervals (CI) were computed, adjusting for age, sex and
HIV status. Results: cutaneous HPV were detected in 44.7% of the SCCC
cases and 10.5% in controls (OR = 6.22; 95% CI = 3.60-10.72). The
strength of the association of cutaneous HPV with SCCC was stronger in
multiple infections than single infections, (OR = 74.2; 95% CI =
23.4-235.7) and (OR = 12.8; 95% C = 5.5-29.6) respectively. Mucosal types
were detected in 6.4% SCCC and 3.5% controls (OR = 1.0; 95% CI = 0.-2.9).
HPV5, 8 and 24 were most common in SCCC. The association of cutaneous HPV
with SCCC was stronger in SCCC patients with HIV (OR = 17.0; 95% CI =
5.5-52.5). HIV infection was detected in 85.1% SCCC and 44.9% controls,
(OR = 7.3; 95% CI = 4.2-12.4). There was no significant association of
SCCC with age, sex, educational level, smoking habits, indoor or outdoor
occupation. Conclusion: Cutaneous HPV and HIV are significantly
associated with SCCC, while mucosal HPV are not significantly associated