Prediction of disease severity in young children presenting with acute febrile illness in resource-limited settings: a protocol for a prospective observational study by Chandna, A, Aderie, EM, Ahmad, R, Arguni, E, Ashley, EA, Cope, T, Dat, VQ, Day, NPJ, Dondorp, AM, Illanes, V, De Jesus, J, Jimenez, C, Kain, K, Suy, K, Koshiaris, C, Lasry, E, Mayxay, M, Mondal, D, Perera, R, Pongvongsa, T, Rattanavong, S, Rekart, M, Richard-Greenblatt, M, Shomik, M, Souvannasing, P, Tallo, V, Turner, C, Turner, P, Waithira, N, Watson, JA, Yosia, M, Burza, S, Lubell, Y