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Diagnosis, Patient Management and Disease Control

Posted: Apr 30, 2015 at 12:32 am   /   by   /   comments (0)

By Akin Osibogun


Disease is the result of a distortion of the physiology or anatomy of any part or several parts of the human body and can generally be due to infectious agents or non-infectious agents. Several reasons have been provided to account for the observed distortions in physiological or anatomical functions. The various reasons and theories in turn account for how disease was diagnosed and treated at different times and in different cultures

If the operating theory is that disease is caused by sin, then the diagnosis of disease as well as its treatment will have to depend on consultation with the gods. Let me confess that I am not an authority in that discipline and I will not say anything further in that regard.

The Germ Theory of disease on the other hand holds as a truth, the existence of microorganisms whose invasion of the human body result in disease. This theory is valid for the class of diseases referred to as communicable diseases.

Communicable diseases are those that can be transmitted from one human being to another. Such diseases are in general characterized by the presence of a biologic agent which either by itself in full or part or by its product can be transmitted to a new and susceptible host. The key points to note are; a biologic agent, a reservoir of infection, a route of transmission and a susceptible host.

As for biologic agents of disease, we have recognised prions, viruses, rickettsia, bacteria, fungi, protozoa and helminthes. We are familiar with all these and I will not spend time on describing each group beyond mentioning that prions are protein elements that are associated with disease causation as for example in the Creutzfeldt-Jacob Disease (or Mad Cow Disease).

Non-communicable diseases are those that are not transmissible from one person to another e.g diabetes mellitus, hypertension, sickle cell disease etc. Please note that inheriting sickle cell genes from ones parent is not viewed as transmission in the context defined above. Non-Communicable Diseases have however been associated with predisposing and exposure factors. The Agent-Host-Environment concept (Theory) therefore advances that disease is as a result of interaction between the human host and some agents in his environment.

An agent of disease in the human environment for example is tobacco. When smoked, it increases the chances of the smoker developing cancer of the lungs. Another example is coal tar which increases the likelihood of those exposed to it developing scrotal cancer.


The Diagnostic Logic

Diagnosis is more like detective work. It requires the assembling of information and drawing reasonable inferences. The very first step of the diagnostic process is history taking which will help in narrowing down the list of suspected diaseases and thereby point in the direction of investigations to be requested that can help to confirm the diagnosis. Symptoms such as vomiting, diarrhea, sleeplessness etc will point in some direction which can be further supported by physical examination to elicit signs.

Signs such as yellowness of the sclera are already suggestive of some liver problems and when the elicited signs are combined with the symptoms, the doctor is in a position to make some differential diagnoses. In other to make more definitive or reliable diagnosis, he will rely on other investigations – laboratory and imaging investigations.

The diagnosis of many diseases now depend on our knowledge of the causative agents and the trail they leave behind in the human body. For many communicable diseases, we may be able to identify either by culture and microscopy, the agent or its progeny; or we may be able to detect levels of antibody that the body has produced in response to the antigenic properties of the agent. For many non-communicable diseases, we may be able to make the diagnosis based on various chemicals released into the blood circulation as a result of the destruction caused by the disease. Such biomarkers have been recorded for Ischamic Heart Disease, Prostate Cancer among several diseases.

Histological changes and their study have also been helpful in our quest to making diagnosis. We have further advanced by combining histology and chemistry to further improve our diagnostic accuracy. Now with Immuno-histochemistry, we can determine and sub-classify breast cancer with implications for improved clinical management.

On the other hand are different imaging technologies starting from the simple X-Ray to the CT Scanner, to the MRI, to the PET Scanner etc that enable us to observe not only gross anatomical changes, but also sliced anatomical changes and anatomic physiological changes. Doppler techniques enable us to study the heart in motion and pick up all kinds of holes in the heart as we observe regurgitation during the pumping of blood by the heart. Blood brain flow studies can help us pick areas of blood vessel narrowing and the sources of Transient IschaemicAnaemia and “simpler” conditions such as absent-mindedness.

Other wonder diagnostic tools have emerged that enable us to peep through small holes and see internal organs and at times through the same equipment effect repairs on malfunctioning internal organs. Thus with the Gastro endoscope, we peep into the lumen of the oeasophagus, detect and band varices or detect and ligate polyps for example. These procedures can be done as a clinic case and the patient can go home same day. Previously, access to the lumen of the distal oeasophagus would have required surgical opening of the chest or abdomen.

In emphasising the importance of diagnosis, let me say that you cannot treat what you do not know except blindly. Yes, you can treat blindly and be correct, but the chances are far better with a proper diagnosis.

Before rounding up, permit me to relate diagnosis to disease control. This is particularly important for me as a Public Health Physician. Recently in Ondo State, some 17 or 18 people were reported to have died due to some strange disease. If the disease remained strange and we do not know the diagnosis, then all kinds of responses become possible including social dislocation of the State. People might just start running away from the State with the suspicion that it could be Ebola. Fortunately, samples from the victims were sent to the Laboratory at the Lagos University Teaching Hospital where the samples were screened for Ebola and some six or seven other viruses and all samples turned out negative. That then allowed further investigation for possible chemical poisoning causes. The control strategies are different for the two possible scenarios. Once viral origin has been excluded, the State Government based on suspicion of chemical poisoning has been advising its citizens to avoid consumption of local gin.

The other example I will give relate to the recent and on-going Ebola epidemic in West Africa.

When on July 21, 2014, a single case of the Ebola Virus Disease was imported into Nigeria via the MurtalaMuhammed International Airport, it took some two to three days for the diagnosis to be made. The sample sent from the First Consultant Hospital in Obalende to the Lagos University Teaching Hospital was reported as positive by 24th July 2015. Once the diagnosis was confirmed, the Lagos State Government was able to rely on its Public Health Laws to implement immediate contact tracing and restriction of movement for anybody considered a public health risk. Other measures including massive advocacy and public mobilization for prevention strategies yielded fruits as the Ebola Virus Disease was contained in Nigeria by September 2015 while the official declaration by the World Health Organization was in October 2015. Without the confirmation of the diagnosis as narrated above, the spread of the virus would have created havoc in such a densely populated area such as Lagos.

In that context, I am happy for this addition to the diagnostic infrastructure and capability in Lagos. I believe this city will continue to be know for its excellence. Once again, I congratulate those who conceptualized and have seen this facility to fruition.


• Professor  Osibogun, former Chief Medical Director (CMD) at Lagos University Teaching Hospital, Surulere, Lagos made this presentation in Lagos