A ‘mysterious’ viral fever is rapidly spreading in Karachi that not only causes symptoms like dengue fever but also behaves like it as it decreases the white blood cells and platelets of the patients.

It even requires the same treatment protocols as dengue fever however, when patients are tested for dengue fever, their results come out to be negative, pathologists and hematologists in the provincial capital have claimed.

Experts say that it can be a variant of the deadly dengue virus but nothing is evident at the moment.

According to Geo News, the head of the Molecular Pathology Department at the Dow University of Health Sciences, Dr. Prof. Saeed Khan, said that the cases of the mysterious fever started appearing in Karachi couple of weeks ago.

He said that all the symptoms and behavior of this viral fever are similar to dengue fever but NS1 antigen tests, the diagnostic test performed to detect the presence of dengue virus, of the patients do not diagnose dengue fever somehow.

Dr. Saeed believes that this mysterious virus could belong to the family of arbovirus -- viral infections transmitted to humans from a group of insects known as arthropods.

“We have even performed the PCR test to see if it is dengue virus but it is not the dengue virus. It is not Zika virus because Zika virus behaves differently. There is also little chances of this virus being any unknown variant of the dengue virus,” Dr. Khan said.

He advised citizens to take necessary precautionary measures against diseases like dengue fever and malaria because blood banks all over the city are already facing an acute shortage of mega units and random units of platelets.