Human-to-human transmission is through inhalation of respiratory droplets which are expelled when an infected person sneezes or coughs or by contact with surfaces that have been contaminated by respiratory secretions and then by touching the mouth or nose. The rate of secondary transmission has been found to be 22-33% [26] . In a study in Kenya the secondary household transmission was found to be 26% [27] . The transmissibility in schools has been found to be around 20% [28] . The incubation period is between 1 and 7 days and an infected person can transmit the infection from a day prior to onset of symptoms to a day after symptoms have subsided.