Many claims of typhoid fever in Nigeria mere conjectures — Scientist

Mrs Petronilla Ozumba is a medical laboratory scientist, and the Deputy Director, Laboratory Services of the Institute of Human Virology Nigeria (IHVN). In this interview, she spoke on factors fueling misdiagnosis and its implications on health service delivery, the best definitive diagnosis for typhoid fever, among others.

Many public and private laboratories in the country have continued to churn wrong and unreliable results. What do you think is fueling this?

Over the years, we have been dealing with unreliable diagnoses and it is becoming rampant. This can be attributed to a lack of skilled health professionals because we are winding down on using rapid diagnostic test kits.

You find out that people go off the counter, purchase these rapid diagnostic test kits, and go to their houses to conduct tests without being properly trained. It is not only about doing the test but also about being able to interpret the testing appropriately. There is a lack of adequate training.

For us laboratorians, before we conduct tests and issue results to the patients, we conduct quality control. You first verify that your device is working appropriately before you go ahead to conduct a test.

But the roadside quack professional would just go ahead, collect samples, and test, without even testing their devices. Remember we live in tropical regions with temperatures within the range of 35-37℃ and some of these devices that are used are stored over a long time and are affected by temperature.

Some do not even know the workings of these devices being used. It is only when one applies quality control measures that you can ascertain that your device is working properly and then you can use it to test and be sure that the results that you are churning out are reliable.

What is the implication of this on quality healthcare service delivery?

When there is a wrong diagnosis, people are placed on treatment that they are not supposed to receive for diseases that they do not have. You also have delayed or inadequate treatment. Most times, it worsens the symptoms, and some can even lead to death.

In some cases, some people undergo a lot of psychological trauma even while waiting for the result of an HIV test; I know what clients go through. It will be worse when you give them a wrong diagnosis and maybe later  apologise. It does not breed trust in the patient.

Most times, there is a waste of resources that you would have used to treat other patients that have that disease. These are some of the issues associated with a wrong diagnosis.

What is your take on the use of the widal test as a method for diagnosing typhoid fever?

The widal test is a rapid test, which detects the presence of antibodies that your body makes against salmonella bacteria during typhoid.

 However, it is not very standard because there are elements to reading and interpreting the results of the widal test. While the widal test can be a useful tool in certain contexts, it has significant limitations that must be considered when interpreting results and making clinical decisions. It should be used in conjunction with other diagnostic methods and clinical judgment for accurate diagnosis and appropriate management of typhoid fever.

The definitive diagnosis for typhoid can be accomplished using blood/urine/stool culture. In this instance, laboratories isolate the salmonella typhi that causes typhoid fever and administer a sensitivity test to determine the relevant antibiotics that can be used.

The widal test has been misused extensively in Nigeria. Because malaria is endemic and has similar symptoms as typhoid fever, most people presenting with febrile illnesses, treat for malaria and when they don’t get well, they go to the quacks on the street to conduct widal test, which most often is overinterpreted as the diagnosis of typhoid fever. But the widal test alone is prone to error, and many claims of a typhoid fever epidemic in Nigeria remain mere conjectures and misuse of the widal test.

In the area of HIV testing, IHVN has been at the forefront of providing laboratory quality management systems. 

Can you briefly tell us about laboratory services in IHVN and how the institute is helping to strengthen laboratory services in the country?

IHVN provides comprehensive services across four states; The Federal Capital Territory (FCT), Nasarawa, Katsina, and Rivers, and we are currently providing services across 383 healthcare facilities. 

We support about 88 clinical laboratories and more than 548 testing points. The testing points support point-of-care /near POC testing. Our services cut across the full complement of HIV testing services – we are talking about counseling, and HIV rapid testing at healthcare facilities as well as within the community where we are implementing what we call community HIV testing.

We also offer HIV therapy both at the healthcare facility and community and that will include drug dispensaries – some people will shy away from going to the hospital to collect their medications, so we use community interventions to make sure that their drugs get to them.

We manage HIV and TB patients within the community and the healthcare facility. We encourage the patients who are positive for either HIV or TB to become part of this care and support the move. For TB screening, we provide integrated service when we go to the community level and also at the healthcare facility. We do tuberculosis screening, we do referrals, and linkages to care, treatment, and monitoring, especially for those that are positive, we also monitor them, their progression, treatment, and adherence to treatment, and monitor those that are failing their first and second-line treatments.

For the mothers, especially pregnant women, what we do is also administer HIV testing, and if they are positive, they will be linked to the prevention of mother-to-child transmission of HIV  (PMTCT) programme and then for their children, the laboratory services that we provide are collecting samples that will be used for early infant diagnosis for the exposed infants so that these results are timely and treatment for the children can commence immediately. 

IHVN is also instrumental in strengthening national laboratory systems. For instance, in the past, IHVN and a few implementing partners we are the only ones that had biotech engineers to maintain and service laboratory equipment across the country.

But now, what IHVN is doing in collaboration with the Government of Nigeria through the Medical Laboratory Science Council of Nigeria (MLSCN) is to establish a National Laboratory Equipment Calibration Centre here in Abuja.

Another major contribution to the nation is the setting up of the West African Regional Bio-safety Certification Centre. We started that last year and we are continuing this year. Last year, it was phased out. What we did was to develop the curriculum and then we trained. We selected about 13 biotech engineers across facilities supported by different implementing partners across the nation.