PUBH 6035 Epidemiology Problem set Uncovering the Science of Public Health

PUBH 6035 Epidemiology Problem set Uncovering the Science of Public Health/An epidemiological investigation was begun on July 1, 2000 among a population of 1,000 individuals.Three individuals were found to have leukemia on July 1st. During the ten-year follow-up period, fivenew cases of leukemia were diagnosed. Among the eight leukemia cases, four deaths occurred duringthe ten-year follow-up period. Two additional individuals, neither of whom had leukemia, were lost tofollow-up at some point during follow-up. None of the remaining 990 study participants became ill, died,or were lost to follow-up during the follow-up period.The diagram below indicates the experience of the 10 study participants, using the following symbols:*:case recognition (diagnosis of leukemia)*:onset of leukemia was prior to start of study period---- :observation period during follow-upX:status at termination of observation (i.e., alive, dead, lost)case -----*-- ----- -------------------------------------XAlive2--------- ----- --*-- --------------------------------XAliveDea3*-- ------ ------ ----- ----------------------Xd4--------- ----- -------XLostDea5--------- ----- -----------------*-- --Xd6--------- ----- --------------------------------*-- --XAliveDea7-----*-- ----- -------Xd8*-- ------ ------ ----- -------------------------------------XAlive9--------- ----- ----------------------XLostDea10*-- ------ ------ --XdWhat was the prevalence of leukemia on January 1, 2005?