If you had a recent viral or bacterial illness, then there can be both anemia and low white blood
. Folate deficiency, lupus, Hodgkin's lymphoma
, some types of cancer, typhoid, malaria, tuberculosis, dengue, enlarged spleen or hyper-spleenism are few other causes. If this blood picture is flu related, then it will improve with time. Otherwise you need further tests for confirmed diagnosis. Take care!