Oily chloramphenicol is recommended by the World Health Organization as the first-line treatment of meningitis in low-income countries, and appears on the WHO essential drugs list . It was first used to treat meningitis in 1975  and numerous studies since have demonstrated its efficacy.    It is the cheapest treatment available for meningitis (US$5 per treatment course, compared to US$30 for ampicillin and US$15 for five days of ceftriaxone ). It has the great advantage of requiring only a single injection, whereas ceftriaxone is traditionally given daily for five days. This recommendation may yet change, now that a single dose of ceftriaxone (cost US$3) has been shown to be equivalent to one dose of oily chloramphenicol.