It's a Haematology problem alright. I wouldn't let them bounce you to another department unless they have some idea of why.
Haemaglobin going missing with no change in billirubin? Skin going orange, which is the classic sign of Haemolitic anemia...
What other department can help? It could be a virus or something like malaria, but you've not been in the country long enough really and I assume Brazilian Docs are fairly used to Malaria.