"Mysterious Viral Fever" Grips Pakistan's Karachi: Report

[Shiloh]

Source: https://www.ndtv.com/world-news/myst...report-2609071

"Mysterious Viral Fever" Grips Pakistan's Karachi: Report
As many as 45 new dengue fever cases have been reported in Pakistan's capital city Islamabad on Friday.
WorldAsian News InternationalUpdated: November 13, 2021 4:55 am IST

Karachi:

Cases of "mysterious viral fever" are being witnessed in Pakistan's Karachi that behaves exactly like dengue fever as it reduces platelets and white blood cells of the patients, local media reported citing field experts.

The News International citing clinicians and pathologists on Thursday reported that when the viral fever was tested for dengue, the result comes out to be negative.

"For a couple of weeks, we are seeing cases of viral fever, in which platelets and white blood cells are dropping while other clinical symptoms are also similar to the dengue fever. But when NS1 antigen of these patients is performed, their tests come out to be negative," Prof Saeed Khan, head of molecular pathology at the Dow University of Health Sciences, said, according to the publication.

Other experts, including physicians and hemato-pathologists from different hospitals of the city, have also confirmed that a dengue virus-like pathogen is circulating in Karachi, causing a disease that is acting similar to dengue fever and requires the same treatment protocols but it is not dengue fever.

A molecular scientist, Dr Muhammad Zohaib, who is associated with the Children's Hospital in Gulshan-e-Iqbal, also confirmed that cases of viral fever, which was not dengue but had dengue-like symptoms, had been witnessed by them as well as several other pathologists in the city...

[JJackson]

I only see an antigen test being used, at least according to the above. This will fail if mutations on the NS1 change the antibody the test is looking for. If they have run PCR with probes from other proteins, or a different NS1 antigen, and it still does not match then it is not dengue. On this evidence it could be dengue but with some change in NS1's protein structure at the test point.

[Emily]

Could it be COVID-19?

https://academic.oup.com/cid/article/73/7/e2444/5892809?login=true

Potential Antigenic Cross-reactivity Between Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and Dengue Viruses

https://onlinelibrary.wiley.com/doi/full/10.1002/cyto.a.24047

Dengue Fever, COVID-19 (SARS-CoV-2), and Antibody-Dependent Enhancement (ADE): A Perspective

[JJackson]

I doubt it as the symptoms don't match and Sars-CoV-2 is too easy to test for and, I presume, has been ruled out. A Flavi virus, Zika or something else in Genus, would give a similar presentation but may not be close enough for a positive antigen test. You know, but other readers may not, I have no medical expertise but am guessing based on very little data and some general knowledge.

[Pathfinder]

Mystery virus takes Karachi by storm
...

Rija Fatima
November 16, 2021

A mysterious disease similar to dengue fever is spreading fast in the city. The disease caused by mosquito bite tests negative for malaria, dengue and other vector borne diseases.

Patients, including adults as well as children, with dengue fever like symptoms such as headache and high fever, are coming to various public and private hospitals, healthcare experts said.

Infected patients undergo various tests to diagnose the mosquitoborne diseases including dengue, malaria, chikungunya and others with negative results.
...
"We are investigating this virus. Our Public Health Lab is in touch with National Institute of Health (NIH) in Islamabad. Their services are also being sought for research so that the mystery virus can be diagnosed early and we can take timely steps to prevent it," Dr Saeed said.

We have also collected several samples. It is important for us to research and identify what this disease is. According to the research done so far, we can say that it is a viral disease and to a large extent it can be called flavivirus which can be called a virus of dengue family

. Interestingly, just as dengue causes platelets to drop very rapidly and we need transfusions, so does platelets in this viral fever. Expressing satisfaction, he said that citizens need not panic. The disease is not as severe as dengue, and fortunately no deaths have been reported so far.
...

https://tribune.com.pk/story/2329627/mystery-virus-takes-karachi-by-storm

[Pathfinder]

A mysterious disease in Karachi?

The “mysterious disease” is behaving exactly like dengue minus the lab result

Dr Rana Jawad Asghar
November 20, 2021

The writer is an Adjunct Professor of Epidemiology at the University of Nebraska and has worked for the US Centers for Disease Control and Prevention.
...
According to reports the “mysterious disease” in Karachi is behaving exactly like dengue minus the lab result. NS1 which is the most common test for dengue has very high specificity of dengue meaning if it says you are positive then most likely this is a true report. However, it is not that sensitive means it could be false negative. Also, many dengue patients of today had dengue earlier by another type. Remember dengue has four viral types and infection with one gives you immunity from that type only. So you could still be infected by other types and secondary infection is more dangerous and increases chances of a false negative test.

It could be another disease too but until someone sitting in a lab identifies a new virus among patient samples, or a good epidemiological study tells us that it may be a new disease, stay focused on dengue. So, my advice to all is to keep yourself protected from mosquitoes by ensuring cleanliness in and around your house. Ensure windows have screens to keep mosquitoes off, wear long sleeves especially in morning and sunset and use mosquito repellents when going outside. Aedes aegypti (dengue mosquito) also spreads chikungunya, Zika fever, Mayaro, yellow fever viruses, and other diseases. ...

Published in The Express Tribune, November 20th, 2021.

https://tribune.com.pk/story/2330194/a-mysterious-disease-in-karachi