Herpetic keratitis in Tanzania: association with malaria

Of 103 patients who presented to a rural clinic in Africa with corneal ulceration, 62 (60.2%) had corneal ulcers which on clinical diagnosis were attributable to herpes simplex virus. There was a strong association between herpetic ulceration and a history of recent malaria; 37 of 62 (59.7%) herpetic ulcers occurred in the 3 month period from April to June which corresponds to the end of the peak season for malaria compared with 14 of 41 (34%) of the non-herpetic ulcers. Fifty per cent of herpetic ulcers had a geographic morphology, 27.4% were dendritic, and 22.6% presumed herpetic ulcers were stromal: 38.7% of herpetic ulcers occurred in children under 5 years of age. Bilateral herpetic ulcers occurred in 16.1% of patients but were more common in children under 2 years of age. Geographic and stromal ulcers tended to heal more slowly than dendritic ulcers (mean time to healing 12.6, 12.2, and 6.6 days respectively), and were more likely to result in severe corneal scarring (45%, 29%, and 0% respectively). Herpes simplex keratitis is a major cause of corneal scarring in Africa. It is often seen in children, may be bilateral, commonly is geographic in morphology, and has a strong association with malaria infection. Because it is not easily preventable, more effort must be made to ensure early diagnosis and prompt, effective treatment in order to prevent severe scarring and visual loss.