My dad started complaining of fever with sometimes with chills from july'2007.though when he went to the doctor, all the reports came normal.later now till September he had fever and when he got admitted in the hospital for hernea operation ,all was fine when again he got serious fever with chills.doctors reported it to be haemmorhagic viral fever but the igG and igM titre for dengue was negative.what is the meaning of that

my dad started complaining of fever with sometimes with chills from july'2007.though when he went to the doctor, all the reports came normal.later now till september he had fever and when he got admitted in the hospital for hernea operation ,all was fine when again he got serious fever with chills.doctors reported it to be haemmorhagic viral fever but the igG and igM titre for dengue was negative.what is the meaning of that
What is haemmorhagic viral fever

Viral haemorrhagic fever (http://www.health.gov.au/internet/wcms/Publishing.nsf/Content/health-pubhlth-strateg-communic-factsheets-vhf.htm)

Please read this link until someone knowledgeable in these matters comes online to help you in detail.