In another instance, a young man was quietly sacked when it was discovered during routine on -the- job medical exams that he harbored HIV. Being a union leader, the company expected trouble and paid him almost twice what other employers with similar problems were given. He went to two separate labs and both certified him seronegative. He pushed his employers to the wall and forced them to disclose the source of his problems. Union told him it could only fight if it became clear he had suffered discrimination. He told them he had his community to fight for him.Youths were mobilized and with the original test results, and the ones he did on his own, the company Physician was forced to go with a small crowd of angry youths to the Teaching Hospital and as tension mounted, the youths waited outside while a confirmatory test was done. The Doctor and lab scientists added other tests including CD4 count. Results showed he had HIV1& 2. He also had hepatitis C and his CD4 count was clearly below the lower limit of the normal range. His people broke into a tumult but soon after apologized to the Doctor for taking him through so much stress and went away.
Medical emergencies involving blood transfusion are very common; and often expose the need for Governments to stop perpetuating falsehood about making essential health care facilities available to Nigerians. Recently a 35 year old woman in the 9th month of her pregnancy developed painless vaginal bleeding and had to be rushed to a Government owned Hospital, because the Teaching Hospital where she was booked was on warning strike . She had lost so much blood by the time she was seen that the major concern was to at least ensure she didn’t die, but there was a problem; she was Rhesus negative-(RH-); a rare blood group and one that is usually difficult to find under such emergency conditions. To compound issues, the anesthetist insisted on two pints of the rhesus negative blood before surgery would commence and no member of the immediate families belonged to that blood group. By the time the two pints of blood was made available, not much attention was given to the baby. The laboratory technician gave a lecture to explain why they couldn’t avail the patients much earlier ,but that was no longer necessary and with the possibility of losing the woman staring us in the face, the issue of giving her blood loaded with HIV no longer mattered. The risk had to be taken and she was given two pints of blood screened and certified free of HIV. She survived but lost the baby -no less a huge price to pay for being pregnant in a country where ordinary citizens are forced to abide in the provinces of the wicked and where public office holders uphold the principles according to Machiavelli, not caring how many people perish as long as they live. Teaching hospitals have quality control and quality assurance but unless you pass through the normal process of getting a hospital card, paying the requisite fees and having blood drawn , labeled and documented, you are not likely to be doing the right thing and, any short cut at the level of the teaching hospital could end in disaster. What you get may not be the correct result .Blood samples passing through unauthorized channels are more likely to be placed in the wrong specimen bottles, mislabeled, undergo inactivation by contamination with usual laboratory disinfectants which kill the virus very quickly. Such samples are also likely to be abandoned for more that 24 hours by which time you may have negative results whereas the virus is there. Teaching hospitals are about the best places where you are sure of the reliability of laboratory results. Is it possible to replicate teaching hospital facilities and conditions in every local government area? Again is it possible to improve the patient-lab relationship in Government approved centers, improve services and make personnel compassionate and patient friendly so people will have confidence in them and the services provided? The answer is yes . It is simply a matter of complete change of attitude on the part of Government and others in charge of these matters. Decentralization with properly trained manpower with up to date facilities is one possible solution. Going about commissioning beautiful buildings with less than ordinary medical equipment and with no trained medical hands will only keep us permanently in stagnation. Like the Biblical Moses, we will only be talking about Canaan(MDGS, Health for all, eradication of this and that), but Nigerians may never see the land where every one has good health, where the sick and the ill don’t have to be flown out for lab tests or treatment.
In towns and cities but commonly in the rural areas, there are many people with doubtful background carrying out lab tests on any body who is willing to fall victim, become convinced and pay. Young men and women, well dressed and carrying expensive hand bags and boxes go from one village to another talking about computer diagnosis whereas they are actually deceiving people. Even learned professionals have at times fallen for these so called mobile multi choice medical people. Perhaps the laws regulating laboratory practice, in Nigeria is so permissive that any thing goes; Pharmacy shops, chemist shops, patent medicine dealers, supermarkets and massage centers now have different HIV/AIDS test kits. Some of these outfits charge small fees and are honest enough to instruct their patients to still go for confirmatory tests; others only consider financial gains, charge huge sums and using age and visual inspection, results are manipulated and written out for the unsuspecting villagers. In these settings not many people insist on confirmatory tests. Because of poverty, people have no choice than to submit themselves to batteries of tests they know next to nothing about including test for HIV/AIDS. So long as there is supervision, some elements of sensitivity and specificity might be possible in these places, but this is unusual. There have been many cases of people wrongly diagnosed and placed on antiretroviral drugs. These drugs are meant for patients. Doctors don’t rush to place patients on them . They may be toxic to the organs when individuals not having HIV/AIDS ingest them over long periods.
It has been argued that you can not do without these people considering the way things are in this country , as opposed to the way they should be, which simply implies that if you cant get what is needed, make do with what is available even if what is available will cause monumental disasters. But then if we are transforming, it has to be done on the living and so people keep asking questions with the hope that God Almighty will in his infinite mercy do something remove the ‘ igneous rock of pharaoh” in the minds of leaders so they can understand that everything is temporary and it is all vanity at the end. On the very relevant issues of education and health in Nigeria there seem to be an obvious neuropsychiatric symptom of flat affect exhibited by people holding offices in high places and who like wax works seem impermeable to all sense of reasoning. They are comfortable employing the most primitive patterns of behavior and creating divisions here and there while at the same shooting poisonous policies at ordinary citizens with so much hatred that you wonder how much stress people can take before they develop immunodeficiency disorders even worse than that due to HIV. And yet they elevate dishonesty to the highest levels by talking about declaring states of emergency in the vital sectors of health and education, ignoring the popular counsel that if don’t want your people to perish, give them knowledge,-of course without knowledge, the people perish. Any Nigerian currently 50 years and older irrespective of gender is living in years of bonus; average life span of adult Nigerians has been drastically reduced, thanks to tormenting policies being cycled and recycled by the same people that only bring poverty, ignorance, all sorts of diseases including those caused by stress such as diabetic mellitus(stress is diabetogenic), hypertension, heart diseases(and heart attack) osteoporosis (glucocorticoids interfere with activities of osteoblasts) etc. The recent statistics that over 70% of Nigerians now live in fear of becoming a victim of one calamity or another is congruent with the above assertion, consistent with the increasing size of the gulf that exists between ordinary citizens and those they willingly elected to take care of their needs; basic needs.
When are we going to harmonize or standardize our procedures for HIV/AIDS voluntary counseling and testing? Why is HIV/AIDS education and management not yet in the curriculum from secondary to tertiary levels? How many of the primary centers have the equipment and trained man power to carry out reliable HIV/AIDS test? What about the people in areas with rough terrain ? and then the issue of religion and culture ? If we might add, how many Teaching Hospitals have the health records of prominent Nigerians including politicians.? How can we rely on results coming out from the various research organizations when certain classes of people do not use any of our health facilities , including the laboratories? A ‘big man” was seen in a big Hospital with clinical features clearly suggestive of Herpes-Zoster Viral infection; multiform rashes, some of them bullous were restricted to one side of the body .When asked to go for voluntary counseling and then HIV test, he walked out furious, pouring verbal invectives on the Consultant dermatologist. He wanted no explanations as to any possible connections between the two.
Physicians have noted that men and women in this country take personal health matters for granted ; and particularly those concerning communicable sexually transmitted diseases. A young lady with recurrent genital tract infection will continue to play around until she develops chronic PID(pelvic inflammatory disease) and consequently, blocked fallopian tubes . That’s when she begins to go from one prayer house to another .When HIV/AIDS is suspect only poor Nigerians make themselves available for laboratory investigations . Many of the Hospitals here, including government owned hospitals do not have health records of prominent Nigerians . How many politicians go to our Hospitals for routine medical lab tests? It is even easier for a medical lab in South Africa owned and operated by Nigerians to receive one thousand Men from Nigeria flying there for PSA(prostate specific antigen) to detect cancer of the prostate , than for an identical outfit located here in this country. Nigerians who have money have no time for condom, in what ever shape or form, male or female . They also do not have the patience to negotiate for safer sex . They are prepared to take risks and simply go overseas for every thing when they feel uncertain . That way hospitals overseas have more health records of Nigerians than we can boast of . This is similar to the current trend in the educational sector where Nigerians now fall over themselves to send children to schools in Ghana . So soon, it has been forgotten that not too long ago, Ghanaians were asked to leave this country ; it was ‘Ghana must go” and that country was not considered good enough even for visits.
Consultants in the relevant departments of the Hospitals in Nigeria have maintained a no- nonsense stance on the issue of voluntary counseling and testing, insisting that every one irrespective of social status appeared physically to have lab test for HIV/AIDS . This has helped to strengthen the capacity of many groups to generalize results of their research findings. At the same time, a large proportion of wealthy individuals living with HIV/AIDS, would rather go for prophylactic(preventive) treatment with antiretroviral drugs , perhaps with no idea of the very low success rate and dangerous side effects associated with that approach. If these men and women have the virus, there are no ways of knowing . They spread the organism through multiple social channels and yet are inadvertently excluded from the statistics . Beyond that whereas partner notification for ordinary people can be done easily following prescribed methods, it is a different situation when dealing with the rich; many issues come up and it remains unsettled who does what. It is not uncommon for men and women with diverge sexual orientation and who have multiple partners to simply suggest that Doctors destroy personal records linking them with sexually transmitted infections ; and so the network of infection continues to increase. Also many educated young people would not want to be seen where people gather to do blood tests .After many years of prevention fatigue , they no longer believe that AIDS is real; more of them are now having unprotected sex, with no plans to go check if they have the virus. They are not captured in the statistics currently being used as the basis for strategies, goals and research.
The complex nature of human immune deficiency/acquired immune deficiency syndrome(HIV/AIDS) stems from the painful understanding that it is life threatening and once contracted, the patient lives with it for life. So early detection of the disease makes for early and effective management decisions aimed at aborting the fear factor , improving the quality of life and reducing morbidity and mortality statistics.
Over the years, laboratory tests to detect the human immunodeficiency virus(HIV) and monitor disease progression(there are people with HIV who progress with the disease) and non progression(other people will have the infection but do not progress with it) , have been refined and have become more sensitive (improvement in the ability to detect the presence of disease in those who actually have it) and specific(better able to show negative test in individuals who truly do not have the disease). Characteristically HIV/AIDS is a disorder of the immune system in which the normal immunity against infection breaks down, leaving the infected person more prone to a variety of infections and other conditions. Acquired immune deficiency syndrome(AIDS) therefore is the final stage of HIV infection. There are two types of HIV infection ; HIV 1 and 2 . HIV 1 is the better known and better characterized of the two . It is generally assumed that HIV 2 shares common bio markers with HIV 1 , but certain contrasting features have been observed ,particularly in the subtypes . Though mixed infection of both HIV 1 and 2 are commonly seen, HIV 1 being more pandemic is the predominant type in Nigeria .HIV 2 is uncommon in Europe and America with the exception of mixed serotypes seen amongst African Americans. In Nigeria however, issues concerning major types and subtypes are chiefly in the provinces of research scientists and other experts in the driving seats of the various HIV/AIDS programs. Both viruses (HIV 1 & HIV 2) are retroviruses that enter the human body through infected blood, semen, vaginal and cervical secretions, breast milk etc. The target cells are usually those that display the viral receptors- CD4(cluster of differentiation group 4) and are seen mostly on the lymphocytes and some other cells. The virus, on entry into the host cells turns them into factories for making the cellular components needed for survival and propagation .After a period of 3-6 weeks, sero-conversion takes place. At this point, the host mounts an immune response against the virus which is detected as antibodies in the blood. The period from when the virus entered the body to that when antibodies are detected in the blood is known as the diagnostic window period. Recent studies have shown that this period may last from three weeks to ten years and even longer in individuals (with mutation for certain HIV co-receptors(CXCR4 & CCR5). During this period, an infected patient may not have any symptoms , but sheds the virus through all the biological fluids in the body; blood(including menstrual blood), saliva, urine, excreta, cough, catarrh etc
Current routine laboratory diagnosis of HIV is mainly based on the detection of specific anti-HIV antibodies. The diagnostic window period is also a disturbing time for patients who may have had situations of unwanted unprotected sexual exposure as may for instance occur in cases of rape ,and consequently want to have phlebotomy for HIV test and be treated .
Since genital sex remains the major route of transmission and the infection is life long , a number of social, moral, ethical and legal issues declare themselves the moment positive test results are mentioned .These issues become further complicated when laboratory tests are done in circumstances where supervision by a medically qualified health professional is absent or where counseling was inadequate ,not done at all or under circumstances where counselor was unable to sufficiently handle issues of confidentiality
In Nigeria, a major problem affecting research in HIV/AIDS is getting reliable data. The reasons are protean; governments at all levels are prepared to release millions and billions of Naira to entertainers and sports enthusiasts without any bureaucratic hurdles as if giving out millions of Naira to celebrities is what the people elected them for. Imagine an elected state Governor giving out as much as 3000US dollars each to participants in the recently concluded ‘BBA(big brother Africa) the chase”; an event that showcased arrant immorality to unimaginable levels. Where did the money come from? People have become so incapacitated that they simply grumble in resignation. These same government officials are notorious for treating issues concerning health and education with so much non chalance that those who are writing have acknowledged that indeed history is being made ; with strange and unusual actors appearing on the stage to the awe and amazement of every Nigerian; young and old . It is relevant to emphasize that aside from the ongoing strikes by university lecturers(ASUU) and Resident Doctors(ARD), some states have witnessed more strikes by certain organized groups compared with others. People like Professor Osibanjo instead of asking for proof that ASUU has done anything by way of research to help the country should ask him self the same question, even as the head of a colossal institution the activities of which are permanently under discussion. He should then go ahead and midwife a law making it mandatory for all public office holders including political office holders to pass through thorough medical investigations including neuropsychiatric evaluation, so that individuals found to have issues with mentation can be identified and possibly disqualified by INEC. If he can do that for this country then he will be held with the same measure of reverence that was given. He should actually be seen to be very worried about the general state of lawlessness in the country, instead of making inuring and contradictory statements . The late Gani fawehimin never minced words; on important national issues, he made his position clear and unambiguous. We should have elder statesmen like that . He fought a good fight while he lived and left it all for Nigerians. It is abnormal for any one entrusted with the lives of other human beings in the same country to exhibit what in the language of Psychiatrist as a flat affect . It is even better when a leader surfers flares of emotion, but to be so flat as if communing with alien world is at best consistent with paranoia.
Unfortunately for the poor in this country, even when Government manages to release funds with support from foreign donor agencies, corruption takes control and so nothing works . Every dispensation and every now and then, one slogan succeeds another; ‘Health for all by the year 2000”, MDGS, vision 20.2020, etc. and nothing comes out of the billions pumped into them.
The medical , moral and legal basis for AIDS screening tests in a number of cases is antibody detection and once established and confirmed in a reliable laboratory, HIV antibody levels will persist throughout the life of the infected person . It has nothing to do with God or Satan. In fact, it is not the will of God that the situation of antibody production in response to the presence of HIV be reversed or undone . The presence of antibody simply means that the patient is assumed to be infected and can infect others ; it does not in any way imply immunity, sleeping around when you are HIV positive whether or not you use male or female condom and are on ART is profoundly irresponsible and dangerous.
What may inform the need to run HIV/AIDS tests?
There are a number of situations that may warrant lab tests for HIV/AIDS;
.Before any surgery
.During pregnancy (as part of routine antenatal care)
. In procedures like endosccopy, laparoscopy, dialysis( including ambulatory peritoneal dialysis , artificial reproduction procedures(ART), before transfusion of blood or blood products, , blood and organ donation .It is in the patients’ interest to ensure it is the practice in centers offering these services before submitting themselves for instrumentation.
.Lab test for HIV/AIDS can also be necessary as usual requirements for marriage, cases of rape to establish pre HIV incubation period status.
” The test is also commonly requested when some clinical conditions emerge that point in the direction of AIDS such as unexplained high or mild elevation of body temperature depending on the HIV subtype) that may have lasted for over a month with disappointing response to the usual drugs for fever associated disease conditions
” . Unexplained weight loss (beyond 10% of body weight) within the setting of a medical history of chronic diarrhea
” .Unusual mouth diseases that were never there before the characteristic symptoms appeared
” Appearance of eye diseases that look like vernal conjunctivitis( popularly referred to as ( Appolo) but this type is accompanied with much redness and plenty of gummy discharge-christened ‘salad cream and tomato ketchup retinopathy” as observed via ophthalmoscope.
” Skin manifestations-boils and weeping lesions
” Yellow eyes with or without pain in the right upper abdomen below the chest when there is co infection with hepatitis
” Brain tissue, involvement is seen commonly these times with Neuro psychiatric manifestations or episodes of seizure and vomiting
Others conditions that could draw attention to the possibility of HIV/AIDS being present include ;- Pseudomembranous type oral Candidiasis, Angular cheilosis, Xerostomia-dry mouth, marked reduction in the quantity of saliva expressed from whartsons or stensons ducts
Also , HIV is commonly found in individuals suffering from pneumocystic pneumonia or pulmonary tuberculosis, syphilis, cytomegalovirus infection, herpes simplex, varicella-zoster, candidiasis, particularly oral with the candida sp.
Though not common, AIDS defining cancers-such as -karposis sarcoma including asymptomatic oral karposis have been documented, as has AIDS related lymphoma
What do we take home from all these ?
A medical person cal take a look at you when you go to the Clinic for something else and then insist that you run certain lab tests in addition to HIV/AIDS test. While you may be surprised ,it will be unwise to do otherwise .It could be a stitch in time. You should feel free to ask questions however uncomfortable it may seem. A small fleshy swelling, firm to hard, swelling that appeared under the skin of the back of the head below the ear , and since it was noticed has refused to go away despite all efforts may have been ignored, but your Doctor might need to see that swelling.
Many patients are now aware of these and many more others that can be tied to the possible presence of HIV/AIDS.
Clinical suspicion for HIV/AIDS should be higher in the following individuals viz;
People who are sexually active and have had unprotected sex in the past few years
Blood recipients , particularly recipients of multiple blood units, other blood products like plasma ,platelets, even if blood was screened
Organ recipients ,
Intravenous drug users, especially those who share needles and syringes
People with multiple partners- not only having many men or many women, but going from one failed marriage to another
Individuals in polygamous and polyandrous relationships
Tattoo and piercing enthusiasts etc, etc.
In the absence of effective, uniform and harmonized HIV/AIDS voluntary counseling and testing policy, problems are unavoidable. Some of these problems are also connected with the rising proportion of illiterate Nigerians. Even the educated seem not to be firm about what they know concerning HIV/AIDS lab tests
Some of the questions encountered can be summarized as here under;
What is the test all about? How is it done? Where exactly do you get a reliable test? What is counseling? Why does any one need counseling? How do you explain false positive and false negative tests? What happens when an individual is said to have borderline HIV/AIDS? How is HIV test interpreted?
What happens when a child tests positive and the parents don’t know their own statuses?
When a partner dies of the disease how does the family he leaves behind handle the issue of knowing their statuses?
In fact, in one situation, the family of a man said to have died as a result of the complications of HIV/AIDS instructed his widow not to go for any tests. She was also not to take any of the children for the test. When she insisted she was going to see a counselor , they told her to pack her belongings .
In many situations, questions related to HIV/AIDS lab tests are never asked as peacefully as would be expected; in fact only few people ask direct questions , and this is because of the many truths and myths bandied around . Understandably , it is difficult in busy centers like the Teaching Hospitals to listen to patients suspected to be harboring the virus skirt around their problems. Some patients and their affected relations at times go to health centers and leave without any official assisting them with little but needed information linking the lab test with the different aspects of HIV/AIDS . Some people wander from one place to another with blood samples and request forms and end up getting no tests done or succeed in getting manipulated results
False positive and false negative results ;possible explanations:
Tests may be sensitive-able to detect the AIDS virus but most of them are not specific, and can cross react to detect other viruses . Well trained laboratory scientists and physicians are able to detect some of these impossible results that defy immunological logic and make appropriate corrections; in other situations, the equipment to make a definite distinction are not available, living the patient in limbo.
Retroviruses, in particular those that infect humans are unstable; they can be easily made inactive or killed by detergents, Savlon, Alcohol, House hold bleach and heat; conditions usually obtainable in the laboratories.
3.Disease progression. Though in asymptomatic individuals the proportion of infected CD4 positive T cells is in the range 1 in 100 to 1 in 10,000, at least one or two viral particles can be detected in every 100 CD4 -positive T-cells by the time patients present with AIDS.
3. Catastrophising or fear avoidance behavior. Some one in a center (usually common with private medicine dealers)may be a catastrophist , so he can sell his drugs and attract more clients and patients .
5. Type of test;Tests based on the p24 core antigen can be picked it up in blood samples 3-6 weeks after infection, but may become borderline positive or even negative after 6 months , after which it now becomes positive once again.
6. Counseling techniques specific for HIV/AIDS may not yield good results if the knowledge base of the counseling official is narrow or inadequate. Medical and social history may not detect the presence of co morbidities. Therefore in patients who are chronic alcoholics, with liver disease(alcoholic Hepatitis), healthy people who have had repeated transfusion of blood and blood products, chronic intravenous drug users, who share needles, discordant couples, non progressors(long term and sort term). Positive results have to be carefully interpreted and confirmation is essential .
7.Types and sub types.Most HIV /AIDS infection involves type 1 and type 2 variants of the virus; type I being more pandemic and of world wide spread compared with type 2 which is more of an African disease,
and each has its own sub types with characteristics not exactly known. Beyond that, only type 1 has been well studied. What is known about the history and clinical course of HIV TYPE 2 at the moment is based on assumptions and not evidence. Physicians and laboratory professionals in resource limited countries therefore face more challenges when they have to make a diagnosis in patients with advanced stages of AIDS and have to contend with the fact that equipment for a more precise diagnosis such as polymerase chain reaction(PCR) are not available , broken down or have no trained personnel to use and maintain them.
8.Lab diagnosis of HIV/AIDS in children is particularly problematic because even up to 18 months of life, maternal antibodies can still be detected in a child; an un infected child born to a seropositive Mom can therefore have a false positive test result, but as will be seen later, modern equipment capable of detecting particles of the virus can pick them up if they are present in a child as early as day 1, or at least 3-6 weeks
When it is indicated to detect HIV infections in adult patients with results marked negative but to repeat test, bother line or indeterminate or in neonates born to HIV/AIDS positive mothers , cultures are the test of choice, only few centers are currently doing this because of issues of technique and safety; Secondly using reverse transcriptase assay, though capable of detecting the subtypes , requires a great deal of expertise to operate. Sending willing Nigerians outside the country to learn specific skills in certain areas in Medical practice including medical laboratory is not likely to make the agenda list of policy makers
Several methods are used in the laboratory to detect the presence of HIV infection in patients. These include screening for antibodies, viral antigens, direct isolation of the virus and viral RNA/DNA test. Whichever method employed, emphasis is placed on the specificity and sensitivity of the tests. Unfortunately this is mandatory only in the very few places in Nigeria where there is quality assurance and where procedures are standardized . The specificity of a test defines the accuracy with which it confirms the absence of an infection while sensitivity is the accuracy with which the test confirms the presence of an infection.
A. Some of the Current Diagnostic HIV/AIDS Tests:
1. Antibody Tests:
These are standard screening tests for HIV infection. They detect the presence of anti-HIV antibodies in blood. These tests are viral antigen (protein) to detect the circulating antibodies. These methods include the enzyme linked immunosorbent assary (ELISA), particle agglutiuation, immuo-floorescence and the western bolt test. The sensitivity and specificity of these methods presently available at commercial systems approaches 100% but false negative and false positive reaction do occur.
Antibody testing from the bases of the rapid screening tests in HIV infection. Apart from ELISA test which takes 2-3 hours to perform several rapid tests and available which give results within half an hour. Rapid tests give a visual reaction a is seen in a dot-blot and particle agglutination. Usually, rapid tests do not require specialized equipment and can be done in small laboratories. Rapid test methods have the disadvantage of not detecting infection when the antibody level is very low.
2. Antigen Tests:
This is used to determine HIV infection usually early prior to the appearance of antibodies. It is undetectable during the latent period (ie when antigen-antibody complexes are present) but could be detected during the final stages of the infection. It has been argued that the routine use of antigen screening test in the transfusion service may result in earlier cases of HIV infection being identified. However, the advantages of method is still being investigated.
3. Supplemental Tests:
These are screening test methods used to confirm the presence of HIV infection. Since a screening test may give false positive results, a combination of three screening tests with different antigens and principles are used before a positive result is declared. This is often ignored in many situations where individuals at risk wait for the appearance of the regular symptoms and signs of HIV/AIDS before taking action.
In line with the national policy of HIV testing in most developed countries, a healthy individual reactive in three different systems of testing is confirmed to be having HIV infection, even if he or she does not have any of the characteristic clinical features enumerated in the early part of this article. Other supplemental tests like western Blot (WB) test and immune fluorescence techniques are used to resolve discordant results obtained from ELISA and the rapid tests. Western blot tests were initially used as the gold standard and confirmatory test for HIV infection, but now it is used for resolving discordant screening results. It is highly specific as it detects HIV Antibodies to specific HIV protein ,the only setback being that it is expensive.
4. Detection of Viral RNA or DNA:
During the diagnostic window period, the individual is highly infectious but anti-HIV antibody tests will be negative. The p24 antigen or HIV RNA may be present prior to or in the early stages of seroconversion. The p24 antigen appears in the blood within two weeks of exposure and remain there for eight to twelve weeks until its corresponding antibodies appear.
The detection of viral RNA or DNA can be done by the Polymerase Chain Reaction (PCR). This is done in laboratories with specialized equipment and personnel. In PCR, the HIV RNA/DNA bolus is amplified from blood cells. This technique can detect the virus even if only very few copies of the viral genome are present. It is highly sensitive and useful in confirming HIV in indeterminate samples of blood especially in neonates born to mothers who are seropositive. PCR based test is only used in specialized laboratories. It is costly and remain mostly as a research tool.
The isolation of virus is done by the co-cultivation of the patients lymphocytes with fresh peripheral blood cells of healthy donors or with suitable culture lines. Eg. T-lymphomas. The presence of virus is confirmed by reverse transcriptase assays, serological tests or by changes in growth pattern of indicator cells. Viral isolation though is tedious and time consuming, and it is successful in only 70-90% of cases.
Pediatric HIV/AIDS test is currently unpopular because we have yet to completely overcome the problems of stigma and discrimination attached to positive test results. When a woman who knows she is HIV positive is delivered of a baby , she could develop nervous breakdown if instructed not to breast feed her baby.
For pediatric diagnosis of HIV, U.S. National Institutes of Health (NIH) working group has recommended the following criteria;
(1) two positive HIV virology tests on separate blood samples, regardless of the infant’s age. As stated earlier the probability of having false positive tests is higher when a single blood sample is used to carry out multiple tests.
(2) a positive HIV antibody test with confirmatory Western blot assay for those 18 months of age or older
To rule out HIV infection, NIH recommends:
(1) two or more negative HIV tests, one conducted at least at 4 weeks of age and the second at more than 4 months of age,
(2) loss of HIV antibody in a child with previous HIV-negative virology assays.
Thus, for infants less than 18 months of age, virology assays-either HIV RNA or DNA PCR-are recommended. At the time of this writing, the number of these machines in Nigeria is less than five
Where the PCR machine is available, it has been recommended that testing should be conducted at three times: 2 to 3 weeks, 1 to 2 months, 4 to 6 months.
For infants older than 18 months, HIV ELISA antibody assays are recommended. The world health organization(WHO) recommends a single viral detection assay at 6 weeks of age for early diagnosis of HIV infection in all HIV-exposed infants.
Tests to determine Prognosis
These are tests used to monitor or measure response of HIV/AID patients to management or treatment of the disease. They include: (i) HIV-antigen (ii) SerumCD4 Count (iii) Viral Load (vi) Neopterin and (v) B12- Macroglobulin. Of these tests, only serum CD4 count and HIV viral load are being routinely used.
(i) HIV Viral Load:
This is of greatest prognostic value and it is measured by assays which detect HIV-RNA copies .e g RT-PCR. The test has also now been established as relevant in monitoring response to antiretroviral chemotherapy. Patients with a low viral loads during the incubation period have better prognosis than those with high loads. Patients whose viral load decreases significantly immediately following commencement of antiviral therapy have better hope of recovery and better quality of life compared with those who fail to show any remarkable degree of response. Agreeably, patients with low pre-treatment viral load have better prognosis .
(ii) CD4 Count:
The increasing use of HIV-RNA notwithstanding, measurement of CD4 still has important value ion monitoring disease progression and the degree of response to antiretroviral chemotherapy. This is particularly true in countries where facilities for sophisticated methods are available, and so while CD4 count gives an indication of the stage of the disease, the viral load gives us an idea about the prognosis(progression).
B. Antiretroviral Susceptibility Assays:
Because of increasing range of ant-HIV agents available, there is increasing pressure on the provision of antiviral susceptibility assays. This has given rise to the emergence of phenotypic and Genotypic assays.
i. Phenotypic Assay: This determines whether a particular strain of virus is sensitive or resistant to an antiretroviral agent. It determines the concentration of drug is required to inhabit the growth of the virus in the laboratory test tubes. The plaque reduction assay used in HIV cases applies only to viruses that are cultivatable. However, there is a caveat; phenotypic assay may not apply in all cases of HIV infection since some strains do not plaque in cell culture.
ii. Genotypic Assay: This method determines mutations that are associated with resistance using molecular biology methods. These methods (in molecular biology) are complex and are not suitable for routine diagnostic laboratory services. Results are also not easy to interpret since HIV mutations occur at a furious pace such that even at the beginning of an infection resistant strains are already present.
INTERPRETATION OF LABORATORY RESULTS
It is important to note that a single positive HIV test is not diagnostic for AIDS; neither is it fool proof for the presence of AIDS-related infections . Rather it should be taken only as an indication of infection with the virus. The proportion of patients with positive HIV antibody that eventually progress to AIDS differs from one geographical area to another. However, the presence of other viral or serious infections, malnutrition, overall health condition of patient and individual genetic predisposition in terms of vulnerability to persistent HIV infection are considered predisposing factors since they have been observed in association with immunosuppressant status , particularly in high risk persons.
Unsupervised HIV testing in the clinical diagnosis of AIDS is not a simple one, especially in developing countries where the viral pandemic can occur in coexistence with other endemic tropical diseases ,confuse the clinical picture, and becloud laboratory diagnosis .A false negative HIV antibody test result in a patient with clinical AIDS, should be repeated on a fresh sample. The risk of inoculation from multiple venepunctures how ever is real and so most lab technicians continue to use the sample instead of drawing fresh blood. In this case, a negative result may be indication that the immunodeficiency is not HIV induced.
OTHER LABORATORY FINDINGS ASSOCIATED WITH HIV INFECTION
Researchers have shown that in most patients, on set of AIDs is associated with low Haemoglobin(Hb) and a rise in erythrocyte sedimentation rate (ESR). In addition, total white blood cell count (WBC), % lymphocytes, and neutrophil are all low in about 30% patients. Thrombocytopenia can occur in about 5.2% in association with a rise in reticulocytes. Serum albumin may drop and bleeding (usually starting with the gums and yellow eyes (haemolysis) may occur due to auto-antibodies. In some cases involving hyperglobulinaemia, there is rouleaux formation. There is associated low CD4 count and a rise in B12 macroglobulin. High incidence of non specific opportunistic infections are commonly observed in established cases of HIV/AIDS
HIV TEST RESULT: Apprehension and Fears
Most infected persons will develop detectable HIV antibody within three months of exposure. With the exception of neonates, infants and children below 18 months of age, negative HIV test usually indicates the absence of HIV infection. If the initial negative test was done within the first three months after exposure, it should be repeated after three months post exposure. The appropriate timing for a follow-up test will depend on the time of exposure, the risk behavior of the person and the persons anxiety. The timing of follow-up test is meant to provide assurance that the exposure did not lead to infection. If the follow-up test is negative, then the person is not likely to be infected with HIV.
PERSONS WITH ONGOING EXPOSURE
For individuals permanently at risk due to ongoing exposure, continued HIV infection and reinjection pose special challenges for follow-up testing. When Mr. A contracts HIV from Mr. B or Mrs. C, the virus while inside him undergoes series of changes such that when an unsuspecting Miss D enjoys sexual liaison with him(Mr. A), a completely new virus with subtypes different from the one originally present before the contact will now be detectable in the body of Miss. D. Periodic follow-up testing is therefore recommended for at risk individuals like commercial sex workers(brothel and non brothel), those who have multiple partners , intravenous hard drug users etc.
CONCLUSION
From the fore going, it is clear that without professional medical advice and some one to guide you, simply jumping into any lab for HIV/ADS lab test is fraught with peculiar problems; there are issues, and questions you need to internalize before you go out there , and hence the need for counseling ;otherwise, you enter a world of confusion like ‘Alice’s adventures in wonder land” . It is important to avoid getting a wrong test the first time, because once a positive result is disclosed and an individual is labeled positive, it is difficult to erase, no matter how hard you try to convince family, friends and foes that there was a mistake. You really don’t know what manner of eccentric characters populate this world of unimaginable wickedness until you have problems ; just as Lewis Carroll tries to tell us in that book. The person you call your best friend also has a best friend and of course some best friends are not as honest and truthful as you think they are especially when it comes to disseminating unpleasant news. Some friends are actually only comfortable when you are in distress. If they can’t get damaging information from you they can get it from your children. So if you are currently enjoying life style patterns that put you( and your family) at risks and are making enquiries ,trying to know your status, you really don’t know to whom you can safely entrust your HIV/AIDS related medical secrets.
Voluntary counseling and testing combined with Clinical judgment is the best approach . It goes beyond just asking questions and getting answers.
WAY FORWARD;
The following suggestions might be useful if favorably considered;
Secondary and tertiary Hospitals rely on different types of loans to ensure all units operate within established fiscal boundaries. They can also accommodate additional units to handle specialized services to take care of different categories of laboratory investigations ,including HIV/AIDS Tests. Running such units will reduce the human traffic , patients’ dissatisfaction and frustrations which characterize regular Hematology and Blood transfusion units . It will also de glove the need for reliable diagnostic equipment and for the units to upgrade their equipment to more sophisticated ones as the needs arise.
Establishment of HIV/AIDS anonymous groups for those who would not want to go to public health centers . Such groups can make special arrangements with approved diagnostic centers coordinated by medical professionals on how voluntary counseling and testing .
The formation of linkage centers where pretest post test voluntary counseling can be done ; coordination of different programs and diagnostic services is essential to ensure access for individuals at risk. Adequate provisions should accordingly be made to facilitate easy communication between clinics and laboratories to ensure appropriate referral and treatment for infected individuals
