ISLAMABAD: The country’s top public health institute, the National Institute of Health (NIH), has directed health facilities and practitioners across the country to stop prescribing two basic tests of typhoid due to the possibility of false positive result, and only stick to “blood culture tests” for diagnosis of typhoid.

“Widal” and “Typhidot” tests are being prescribed as a majority of labs don’t have the facility to conduct blood culture tests.

According to an expert, both tests are becoming the reason for spread of extensively drug-resistant (XDR) typhoid fever in the country that does not respond to most antibiotics. He said the country was already exporting poliovirus and for the last few years it was being blamed for exporting Antimicrobial Resistance (AMR) bacteria of typhoid.

NIH said in a letter that it has come to the knowledge of the institution that some clinical laboratories and hospitals, particularly in flood-affected areas, are still using “Widal” and “Typhidot” tests for confirmation of typhoid fever.

Blames them for spread of XDR typhoid fever in country

“Keeping in view the outbreak of typhoid fever in the country, it is re-emphasised that Widal and Typhidot tests cannot be used for confirmation of typhoid fever and should be discontinued with immediate effect. The only confirmatory test is blood culture test,” it stated.

Through the letter, sent to health departments of the four provinces, Surgeon General of the Pakistan Army and the federal health ministry, authorities have been requested to have a thorough check on laboratories performing those tests.

A senior officer of NIH, who is an Infectious Disease Specialist, told Dawn that almost a decade ago Widal test was discontinued across the world and Typhidot test was also either stopped or discouraged in most of the countries of the world.

“Both tests can show false positive reports which means that a patient is not suffering from typhoid, but report shows him infected with typhoid bacteria. Resultantly doctors prescribe antibiotics to those patients which become a reason for Antimicrobial Resistance (AMR),” he said.

He said the cost of Typhidot test was just Rs150, but it was charged around Rs1,000.

“Although blood culture test, which is the best test to diagnose typhoid, costs around Rs2,000, a majority of labs don’t have the facility to conduct that test. So labs pay commission to doctors to prescribe Typhidot test and it is mostly prescribed across the country,” he said.

In 2018, an advisory, issued by leading national public health institute of the United States regarding the outbreak of XDR typhoid fever in Pakistan, had panicked national and international health circles as Pakistan was already exporting the polio virus and then it was being blamed for exporting AMR bacteria of Typhoid. The advisory issued by the US institute, the Centers for Disease Control and Prevention, stated that there was an ongoing outbreak of XDR typhoid fever in Pakistan that did not respond to most antibiotics. During 2018, cases had been reported in the United Kingdom and in the United States among travellers returning from Pakistan.

The bacteria have an internal intelligence due to which, because of excessive use of antibiotics, it changes itself according to the medicine and creates resistance against the medicines. In the past, bacteria could be killed with low potency medicines but now for the same bacteria high potency medicines are required which is due to AMR.

The NIH official further said that if irrational use of antibiotics continued Pakistan will have a large number of patients having XDR typhoid virus.

The NIH is involved in multi-disciplinary public health-related activities like diagnostic services, research and production of biologicals for the last over 40 years.

The institute is a World Health Organisation (WHO) collaborating centre for viral diagnostics and regional reference laboratory for polio in addition to being a national reference center for diagnosis of influenza. It also works as the national laboratory for quality control of drugs and quality control of food.

Published in Dawn, December 23rd, 2022