Estimating the cost of illness of acute Japanese encephalitis and sequelae care in Vietnam and Laos: a cross-sectional study by Nguyen, ALT, Slavkovsky, R, Phan, HT, Nguyen, HTT, Vannachone, S, Le, DH, Dubot-Pérès, A, Vongsouvath, M, Dinh, ST, Marfin, AA, Letson, GW, Vu, HM, Tham, DC, Mayxay, M, Ashley, EA, Pham, TQ, Pecenka, C