INTERVIEW: Why early diagnosis is crucial in preventing disease outbreaks – Virology Professor

Outbreaks of infectious diseases in Nigeria are worsened by delayed or incorrect diagnosis, weak surveillance systems, and misdirected public health priorities. While early laboratory diagnosis is crucial to containing the spread of disease, Oyewale Tomori, a professor of virology and disease control, says detection must begin with timely community reporting and efficient surveillance.

In this interview with PREMIUM TIMES, Mr Tomori discusses the importance of early diagnosis in epidemic prevention.

PT: How crucial is early laboratory diagnosis in preventing a disease from escalating into an epidemic?

Mr Tomori: Before early laboratory diagnosis, there must be early reporting and detection. You can conduct laboratory diagnosis, only after you have the appropriate samples to test.

Many of the bacterial and viral diseases start with the same “malaria-like” signs and symptoms, which include fever, body aches, headache, vomiting, diarrhoea, etc.

Therefore, the earlier you detect and confirm a disease, the earlier you can mount an appropriate response. Without the lab, you may be treating yellow fever as malaria, and the sporadic and initial cases spread, raging and racing to become epidemics/pandemics.

Note again, the crucial point is detection of new cases/outbreaks before the lab comes in to conform. This stresses the importance of the efficient and effective surveillance to detect the cases. The role of the community in the early reporting of cases is also very important.

PT: What are the biggest challenges in diagnosing infectious diseases, especially in resource-limited settings?

Mr Tomori: First, we need to correct the impression that we are “resource limited.” When you look around our towns, states, and the country, you will see we are resource-wasteful and resource squandering.

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Let me illustrate with a common example. The governor wakes up every morning and travels one kilometre or less between the governor’s house and the office, with an entourage of 10 to 12 vehicles.

The Primary Health Centre (PHC) or the disease surveillance unit, located between the governor’s house and the office does not have a single operational vehicle, not even a bicycle. And you say we are resource limited?

So, the biggest challenge is our misplaced and misdirected priorities. If we spend one-tenth of the excessive resources we squander on the existing governance, poor governance at best, then we can take care of the other challenges we face in diagnosing infectious diseases. We will have enough funds and resources to create an enabling environment, reliable and dependable disease surveillance, accurate laboratory diagnostic facilities handled by a well-trained and experienced health workforce, to detect, diagnose and confirm infectious diseases.

It is a matter of our government reordering national priorities, allocating and spending with accountability the needed funds for reliable disease surveillance, backed by adequately staffed and equipped laboratories provided with required reagents and consumables.

PT: How does delayed and incorrect diagnosis contribute to the rapid spread of diseases within a community?

Mr Tomori: It is obvious that if you do not have the correct diagnosis of sporadic cases of a disease, you mount a blind response, allowing the outbreak of a few cases to spread and transform into an epidemic.

Our country is a particularly good example of the combination of incorrect diagnosis preceding ignorant and blind response. I am sure you are aware of millions of false typhoid diagnoses, leading to unending and ineffective treatment, often with fake antibiotics. So, when your diagnosis is delayed, the disease spreads unabated. When the diagnosis is incorrect, you end up responding to the “wrong” outbreak.

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Either delay or incorrect diagnosis will result in failure to respond on time, or responding to the wrong disease, and consequent continuing spread of the disease.

PT: What role can technology play in improving disease diagnosis and surveillance?

Mr Tomori: Technology leads to improved diagnostic methods and shorter testing periods, resulting in faster and more accurate diagnosis.

The generation of the 70s and 80s provided lab results within four to six weeks of the onset of a disease, by which time the patient is dead and buried.

The current generation is providing lab results within two to four days of onset of disease, by which time the patient is still sick, and may or may not recover. We are moving to a future generation of lab experts who will provide laboratory results 24 hours before the patient is infected, thus preventing infection.

Laboratory diagnosis is going through rapid transformation. This is the age of genomics, with better refined tests leading to more accurate definitions of the disease.

PT: Can you highlight any successful case studies where early diagnosis helped contain an outbreak?

Mr Tomori: The 2014 Ebola outbreak in Nigeria is case in point. Let us compare the West African outbreak with the Nigerian situation.

The index case arrived in Nigeria on 20 July 2014. Laboratory tests provided a diagnosis of Ebola Virus Disease within four days on 24 July 2014. On 20 October 2014, Nigeria was declared free of Ebola, with 20 cases and eight deaths.

Contrast the situation with the West African Ebola outbreak. The index case was in Guinea sometime in December 2013. However, the case was not reported until March 2014. The epidemic, which was declared over in June 2016, affected 10 countries with a total of 28,652 cases and 11,325 deaths (including the 20 cases and eight deaths in Nigeria).

Nigeria stopped the outbreak from spreading through early detection and isolation of the index case, rapid laboratory testing, coordinated and effective contact tracing, community engagement and involvement under responsible government leadership and international collaboration.

PT: How can the government and health organisations strengthen diagnostic systems to prevent future epidemics?

Mr Tomori: As I said earlier, it will require the government at all levels – federal, state and LGA – prioritising pandemic preparedness through effective and sustained disease surveillance system supported with a reliable laboratory diagnostic facilities and structures, with well trained staff, laboratory infrastructures with facilities, reagents and consummate.

There must also be an effective specimen transport system. Adequate funding must also be provided for the effective operation of the surveillance and laboratory systems.

PT: What strategies can be implemented to ensure rapid and accurate diagnosis, even in rural or underserved areas?

Mr Tomori: A tiered national laboratory network system coordinated by the Nigeria Centre for Disease Control and Prevention (NCDC) and covering the entire nation must be in place. The objective is to ensure access to appropriate laboratory facilities by every Nigerian.