Protection from cholera by adding lime juice to food - results from community and laboratory studies in Guinea-Bissau, West Africa

Epidemiological studies have shown that food plays an important role in the transmission of Vibrio cholerae, and different foods have been incriminate d in many epidemic outbreaks of cholera. Storing contaminated meals at ambi ent temperatures allows growth of V. cholerae. Some ingredients such as lim e juice may inhibit the survival of V. cholerae in foods. During an epidemi c caused by V. cholerae O1 in Guinea-Bissau in 1996, a case control study w as conducted in the capital Bissau, the main affected region with an attack rate of 7.4%. Cases were hospitalized patients and controls were matched f or area, gender and age. Lime juice in the sauce eaten with rise gave a str ong protective effect (odds ratio [OR] = 0.31, 95% confidence interval [Cl] = 0.17-0.56), and tomato sauce was also protective (OR = 0.36, 95% CI = 0. 24-0.54). On the other hand use of a bucket for storage of water in the hou se was associated with increased risk (OR = 4.4, CI = 2.21-8.74). Laborator y experiments to elucidate the inhibitory effect of different concentration s of lime juice on survival of V. cholerae in meals showed that V. cholerae thrives in rice with peanut sauce, hut lime juice Inhibited its growth. Si nce lime juice is a common ingredient of sauces, its use should be further encouraged to prevent foodborne transmission in the household during choler a outbreaks.