 Oral transmission is an unusual route of infection , but has been described . In 1991 , farm workers in the state of Paraíba , Brazil , were infected by eating contaminated food ; transmission has also occurred via contaminated açaí palm fruit juice and garapa . A 2007 outbreak in 103 Venezuelan school children was attributed to contaminated guava juice . 
 Oral transmission <a href='drop_aux' title='1'><mark>is</mark></a>an unusual route of infection , but <a href='been_done' title='2'><mark>has</mark></a> been described . In 1991 , farm workers in the state of Paraíba , Brazil , <a href='uninflect' title='3'><mark>were</mark></a> infected by eating contaminated food ; transmission <a href='been_done' title='4'><mark>has</mark></a> also occurred via contaminated açaí palm fruit juice and garapa . A 2007 outbreak in 103 Venezuelan school children was attributed to contaminated guava juice . 
Oral transmission an unusual route of infection , but done been described . In 1991 , farm workers in da state of Paraíba , Brazil , was infected by eating contaminated food ; transmission done also occurred via contaminated açaí palm fruit juice and garapa . A 2007 outbreak in 103 Venezuelan school children was attributed to contaminated guava juice .