HIV and AIDS: The Never-Ending Story

HIV virions budding and releasing from an infected cell. Source

FIGURE 6.1 HIV virions budding and releasing from an infected cell. Source: NIAID, NIH

BLOOD IN THE OR

I have always loved the operating room. I'm a pediatric cardiologist, not a surgeon, but most of my critically ill patients were babies with heart defects for whom surgery was the only effective treatment. Congenital heart defects occur because of the complex process of cardiac development that begins in the early weeks of pregnancy. The heart develops from a tiny tube that folds and twists and involutes and expands to ultimately reveal the four chambers of the normal heart that receive blue blood back from the great veins and pump oxygenated red blood from the lungs out to the body. An error in cardiac development at any stage can result in a defect in the heart's structure - and in some newborns, these defects are fatal without emergent correction. When I started in pediatric cardiology, congenital heart surgery was just out of its infancy and pediatric cardiovascular surgeons were beginning to attempt complete repairs in newborn infants with critical structural defects when no other good option was available. In those days, the field was still new and very small so cardiologists and cardiovascular surgeons worked together very closely. Cardiologists made the baby's diagnosis using cardiac catheterization, a technique that involves threading a tiny catheter from the blood vessels in the leg up into the heart where radio-opaque dye is injected to visualize the anatomy in detail. Once the diagnosis was established, cardiologists met with the surgeon to plan the surgical approach. My teachers - pioneers in the field of pediatric cardiology - always went to the operating room with their patients and so did I. After all, besides the surgeon himself, the cardiologist was almost always the only other person in the operating room who understood the problem.

I am talking here about open heart surgery - and when the heart is the size of a golf ball as it is in a newborn baby, this means some of the most technically challenging procedures imaginable. Open heart surgery is exactly that - opening the heart to perform surgery - and this means that the heart has to stop beating and the body's circulation has to be supported for the surgeon to work. This is accomplished with a heart-lung or cardiac bypass machine to which the unoxygenated venous blood is directed as it drains above and below the heart. The bypass machine oxygenates the blood, simulating the way the lungs function in life, and then routes it through a tiny catheter - smaller than a drinking straw in a newborn - into the aorta, the great vessel that carries blood away from the heart. A roller pump drives the oxygenated blood from the heart-lung machine through the aorta, to the heart muscle itself and to the entire body. It is cardiac bypass that allows the surgeon to stop the heart, visualize the anatomy and correct the defects.

The heart revealed is a thing of great beauty, lying just under the breastbone, pumping continuously from the first weeks of pregnancy to the end of life. It has always been a magical moment for me to see the anatomy that

I had worked to diagnose revealed, and to watch the intricate steps involved in cardiac repair. My respect for the courage and skill of pediatric cardiovascular surgeons still verges on reverence. When the repair has been completed and the heart begins to pump again, I am always filled with awe. After all these years, open heart surgery in a newborn still feels like a miracle.

But open heart surgery does expose the operating team to an enormous amount of blood. Every step involves blood - venous blood flowing, arterial blood pumping, random blood splashing - and sharp objects: saws, needles, scalpels, retractors. There is obvious, ongoing risk of trauma to the hands, evading protective gloves, of blood spurting onto the face, into the eyes. Many times, I remember seeing a surgeon's forehead dotted with blood above his mask. Blood exposure was always an issue, but it suddenly became a major risk after the AIDS epidemic began. Our knowledge about AIDS in medical practice followed the epidemiologic pattern as it was uncovered by reports in the literature. At first, it was a strange new disease that attacked the immune system of young gay men causing unusual infections and malignancies - a problem for specialists in infectious disease and oncology. But less than a year after the very first cases, AIDS was reported to be caused by a transmissible agent carried in the blood - and suddenly it became a problem for all healthcare providers and especially for surgeons. Because the agent had not been identified there was no way to test for its presence and AIDS cases occurring after blood transfusions showed the agent was present in the blood supply. Open heart operations using cardiopulmonary bypass represent the largest routine exposure to blood in clinical medicine, so cardiac surgical teams were thought to be at the greatest risk of accidental infection with the unknown agent that caused AIDS. Cardiac surgeons are among the bravest people I know, routinely facing the challenge of literally stopping the heart to repair it - but I have never seen fear like that I saw in the faces of my colleagues during those terrible early years of the AIDS epidemic. For adult cardiac surgeons, the possibility of exposure was even greater because intravenous drug users were at high risk for both AIDS and infected heart valves requiring urgent open heart repair. Early in the epidemic, an anonymous survey of cardiac surgeons suggested that almost 30% would not operate on a person with AIDS because of fear of infection.3

The dilemma of the contaminated blood supply continued from 1982 until 1985, long after the human immunodeficiency virus had been identified because of the conflicting priorities of the key groups involved: the public health community led by the CDC were convinced of an impending disaster involving potentially many thousands of recipients infected by contaminated transfusions of blood and blood products while the blood-banking community was concerned about fear of AIDS compromising their critical supply of donors. Without a definitive test, potential solutions were suggested and rejected while doctors struggled to deal with terrified patients and families as well as their own fears. During this time, many adults donated their own blood in advance of an operation, a complicated effort that involved going to a blood bank weeks before surgery when up to three units of blood could be taken and stored. Obviously, this was not an option for children or in an emergency situation so the process of directed donations arose in response to concerns about blood safety raised by the AIDS epidemic. A directed donation occurred when a patient's family and friends donated blood to be used only for that specific patient. Directed donations were extremely common before open heart surgery in the children I cared for in the early 1980s.

By 1985, an effective HIV screening test had been developed and within 6 months, the blood supply was declared safe - but not until more than 12,000 people in the United States had received contaminated transfusions of blood or blood products. By that time, the healthcare industry had a much greater understanding of the risk of infection related to multiple procedures including simple routine tasks like blood drawing. In terms of surgery, the procedures that exposed surgeons and their assistants to infection from contaminated blood had been found to primarily involve passing devices between operators, with the highest risk associated with suture needles followed by scalpel blades and glass syringes. In a study of 234 observed surgeries, an astonishing 50% were reported to involve glove perforation with contamination of a co-worker's hand with blood.b A 1992 glove study showed 51% hand contamination with single gloves versus 7% with double gloves - this report led to implementation of double gloving as a routine universal precaution along with masks with shields that protect the eyes.c Between 1985 and 201 3, the CDC reported there were 58 confirmed and 150 possible cases of occupationally acquired HIV infection among American healthcare workers. Nurses were the largest affected group, with 41% of confirmed cases; there were no confirmed cases in surgeons.d

Pediatric cardiology progressed enormously during my time in the field - we almost always make the diagnosis of even the most complex congenital heart defects with ultrasound now, and surgical procedures that were revolutionary in the early days have become almost routine. Often, non-surgical, catheter- based procedures have replaced or augmented surgical approaches. And infection of the blood supply with HIV has been replaced by the risk of exposure to other serious viral pathogens like the hepatitis C virus.e The risk for healthcare workers of HIV infection due to exposure to contaminated blood has all but disappeared, but this history remains an important part of the story of AIDS.

aCondit D, Frater RWM. Human immunodeficiency virus and the cardiac surgeon: a survey of attitudes. Ann Thorac Surg 1989; 47: 182-186. b Palmer JD, Rickett JW. The mechanisms and risks of surgical glove perforation. | Hosp Infect 1992; 22: 279-286.

cQuebbeman EJ, et al. Double gloving: protecting surgeons from blood contamination in the operating room. Arch Surg 1992; 127: 21 3-21 7. dCDC. Guidelines for prevention of surgical site infection. Inf Control Hosp Epidemiol 1992; 20(4): 247-248.

eCDC. Notes from the field: occupationally acquired HIV infection among health care workers - United States, 1985-2013. MMWR 2015; 65(53): 1245-1246.

'CDC. Recommendations for health care workers potentially exposed to hepatitis C. April 2018. www.cdc.gov/hepatitis/pdfs/testing-followup-exposed-hc- personnel.pdf. Downloaded August 14, 2018.

 
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