The Epidemiology of Microbial Keratitis in South Western Uganda

Background: Microbial Keratitis (MK) is the leading cause of unilateral blindness after cataract in Tropical regions and is responsible for 2 million cases of blindness per year. In Sub-Saharan Africa, MK is a neglected problem, most ophthalmic centres do not have diagnostic services, patients present late, appropriate drugs are often not available, corneal transplant services are rarely available. Subsequently, outcomes are poor in this area. Currently there are very limited data to guide policy and practice. Methods: In a main cohort design, individuals with MK presenting to the two referral eye hospitals in South Western Uganda were enrolled over a one-year period. Clinical history and presentation journey were recorded. Their eyes were carefully examined, and samples were collected for microbiology. Patients were tested for HIV and Diabetes. At three months, patients were followed up in their homes and at this point healthy community controls were enrolled to compare risk factors in a nested case-control study and assess the impact of the disease on the Quality of Life (QoL). A separate situation analysis survey of lower health centres was additionally conducted to understand the role of the health system in management of MK. Results: Three hundred and thirteen individuals were enrolled. Median age was 47 years (ra nge 18-96) and 174 (56%) were male. Median presentation time to the eye hospital was 17 days from onset (IQR 8-32). Trauma was reported by 29%. Majority presented with severe in fections (median infiltrate size 5.2 mm); 47% were blind in the affected eye (vision <3/60), fu ngal cases were 62%. At 3-months, 30% of participants were blind in the affected eye, while 9% had lost their eye from the infection. Predictors of poor vision at 3-months were: baseline vision (aOR 2.98 [95%CI 2.12-4.19], p<0.0001), infiltrate size (aOR 1.19 [95%CI 1.03-1.3 6], p<0.020) and perforation at presentation (aOR 9.93 [95% CI 3.70-26.6], p