SARS Update

SARS (Severe Acute Respiratory Syndrome) is a viral infection that has recently become a source of concern among public health officials.  First identified in Vietnam, cases of SARS have now appeared in China (in Hong Kong and Guangdong province, in particular), Singapore, Indonesia, Canada, Thailand, the Phillipines, and the United States.  Approximately another dozen countries have reported possible cases of SARS within the past several days.  At the present time, nearly 1600 cases SARS, including 54 deaths, have been reported throughout the world by the WHO and CDC.  Although the causative agent of SARS is not fully understood at this time, it appears to be a previously unknown member of the coronavirus family of viruses.  Sadly, the Italian physician who first identified SARS in a German businessman under his care in Vietnam has, himself, now died of the disease. 

According to the US Centers for Disease Control (CDC) and the World Health Organization (WHO), the symptoms of SARS include high fever, sore throat, dry cough, shortness of breath, and decreased white blood cell and platelet counts.  Other typical symptoms of viral infection may occur with SARS, including headache, muscular pain and stiffness, loss of appetite, malaise, confusion, rashes and diarrhea.  The incubation period for SARS appears to be relatively short, ranging from 2 to 7 days following initial exposure.  Based upon the rather high prevalence of infections among healthcare personnel, the WHO has indicated that close and sustained contact with infected persons may be necessary to spread SARS.  In particular, contact with respiratory droplets from coughs and sneezes, as well as direct contact with bodily secretions, are thought to be important infection vectors.  However, recent reports of SARS spread among tenants within apartment buildings in China, and at least one case involving a flight attendant on a Hong Kong-based airline, suggest that the SARS virus may be passed with more casual contact. 

The treatment of patients infected with the SARS virus is similar to that recommended for other serious viral respiratory infections, as there are no antibiotics that have any activity against such diseases.  The current recommendation is that patients with SARS should be kept in respiratory isolation wards.  Supplemental oxygen, inhaled medications to keep the airways clear of secretions and to prevent collapse of small airways, control of excessive fever, intravenous fluids to support blood pressure and vital organs, and, in some cases, mechanical ventilation, are mainstays of supportive treatment.

At the present time, public health officials are not advising prospective travelers to cancel their trips overseas.  However, some officials are now suggesting that travel to endemic areas be deferred if possible.  Some flight attendants and travelers have taken to wearing surgical face masks in an effort to reduce the risk of inhaling respiratory aerosols from potentially infected persons, although the efficacy of this strategy is uncertain at this time.  If you—or anyone you know—has recently developed a severe upper respiratory infection, particularly following travel to one of the countries mentioned above, then medical care should be urgently sought.  While there are hundreds of other viruses that can cause the same symptoms as SARS, the virulence of the virus causing SARS seems to approach, at least in some cases, that of strains of influenza that have caused pandemics of severe illness and death in the past. 

Update on Smallpox Vaccine

The CDC announced, on March 25^th, an advisory regarding the administration of the smallpox vaccine to people with a history of heart disease.  More than 30,000 healthcare workers have recently received the smallpox vaccine as part of recent Homeland Defense initiatives.  Among these volunteers, seven have developed cardiac-related complications, although it is presently unknown if these complications are directly related to the vaccine.  Among these seven stricken healthcare workers, three have experienced heart attacks (one of which was fatal), two cases of angina (chest pain due to blocked coronary arteries) occurred, and two cases of myopericarditis (inflammation of the heart muscle or the fibrous sac that surrounds the heart) occurred.  The CDC is currently studying the medical histories of each of these seven patients, and is carefully evaluating their cardiac disease risk profiles (at least one of these patients was reported to have had an extensive history of preexisting heart disease).  While cases of heart inflammation were reported during the period when smallpox vaccine was most extensively administered (in the 1960s and 1970s), no epidemiologic studies were carried out at the time in order to ascertain any causative effect by the vaccine.

As it is currently unclear whether or not the smallpox vaccine, which consists of a live virus that is related to the smallpox virus, is linked to these few cases of cardiac complications, the CDC is being somewhat circumspect in its advisory.  The CDC is now recommending that persons with a history of cardiomyopathy, heart attack or angina, or any other evidence of heart disease be temporarily deferred from receiving the smallpox vaccine.

Inflammatory Markers & Risk of Heart Failure

There is growing evidence that the progression of coronary artery disease is influenced by mediators of inflammation.  Most recently, C-reactive protein has taken center stage as a key inflammatory protein that appears to play a critical role in the development of coronary atherosclerosis.  While coronary artery disease has been linked with inflammation and, in turn, directly with the risk of developing a heart attack, another equally life-threatening cardiac ailment has not previously been associated with inflammation.  Congestive heart failure (CHF), which most commonly occurs after a heart attack permanently damages heart muscle, is a common cause of disability and death among older Americans.  As its name implies, CHF results when the heart becomes sufficiently damaged so that its ability to pump blood to the body becomes seriously impaired.  Patients with CHF may have difficulty breathing due to fluid build-up in their lungs, and often experience debilitating weakness and fatigue as a result of inadequate oxygen delivery throughout their bodies.  Swelling of the lower extremities may also cause difficulties for patients with CHF. 

A new study in the journal Circulation looks at the potential role of inflammation in patients with CHF who have never had a heart attack before.  This study was conducted within the framework of the highly respected Framingham Heart Study, one of the longest running and largest heart study research programs ever undertaken.  In this new study, a total of 732 elderly patients who entered the Framingham Heart Study without any prior evidence of CHF or heart attack were followed for an average of 5.2 years.  All study volunteers underwent extensive blood tests upon entry into the study, which included assays for known mediators of inflammation, including C-reactive protein, interleukin-6, and tumor necrosis factor-alpha.  Among the 732 volunteers, 56 of them subsequently developed CHF—without experiencing any heart attacks—during the course of this study.  The study determined that initially elevated levels of any of these inflammatory mediators were significantly correlated with the subsequent development of CHF among the study volunteers.  Among patients who had elevations in the blood levels of all three of these markers upon entering the study, the risk of subsequently developing CHF was more than four time higher when compared to other study volunteers without elevated levels of these inflammatory markers.  The study’s authors concluded that a single measurement of inflammatory markers in the blood was highly predictive of the risk for subsequently developing CHF, even in the absence of heart attacks.

Breast Fibroadenomas & the Risk of Breast Cancer

The presence of benign fibrous nodules in the breast, called fibroadenomas, has been linked, in some studies, to a slightly increased risk of developing breast cancer.  Other benign breast conditions, including ductal hyperplasia, and even a history of prior breast biopsies for benign lesions, have been statistically associated with small increases in breast cancer risk as well.

A new study in the Archives of Surgery looked at 32 patients with fibroadenomas occurring in the breast at the same time as breast cancer.  These patients were compared with 26 control patients who had breast fibroadenomas without the concomitant presence of breast cancer in the same breast.  The researchers used several highly sensitive tests to assess both the fibroadenoma tumors and the breast cancer tumors for characteristic genetic mutations associated the development of cancer.  The study determined that fibroadenomas of the breast, whether or not they co-existed with breast cancers in the same patient, did not contain any of the genetic mutations commonly identified in the breast cancer tumors.  From these results, the authors infer that fibroadenomas are not directly associated with the development of breast cancers.  This small study should be repeated with larger numbers of patients to validate its findings.  However, these results should provide considerable reassurance to women with benign fibroadenomas of the breast.

Dr. Robert A. Wascher