What Are Dx Clusters?

A Dx, or disease, cluster is a situation in which one geographical region, neighborhood or social group is afflicted by the same illness. When a person is seen at an emergency room or clinic for a disease suspected to be grouped with others, the case information is added to local and national disease data banks. As more cases develop, the prevalence is studied for any overlaps in risk factors, symptoms and occurrence.

Geographical Clusters

• Diseases that are prevalent in numbers to a particular geographical region in the country can often be linked to bacteria, virus or radiation exposure. For example, the incidence rate of melanomas, a skin cancer, are often higher among populations located near the equator as a result of their exposure to sunlight. The "Encyclopedia of Biostatistics, Second Edition" adds that there are also underlying lifestyle, hereditary and lifestyle factors which can be important in making predictions about ethnic groups. In circumstances where particular ethnic or social groups have migrated and settled, the disease prevalence does not change and can even increase in cases of infection.

Heredity

• Heredity is a common cause of disease clusters, especially when the geographical region is comprised of individuals of the same racial or ethnic background. In larger cities and throughout the Midwest, it is not uncommon for racial and ethnic groups to settle in one area. They often share prevalence for a particular disease that would make clustering seem like the underlying cause. "Environmental Health Perspectives," a peer-reviewed journal, suggests that when looking for these biomarkers, it is imperative to explore blood, urine, breast milk, feces, adipose tissue, hair, nails, semen, exhaled breath and cells in the diseased body.

Environmental Factors

• Environmental factors can include soil, air, water, food supply, toxins and radiation exposure. Generally, exposure to environmental dangers in the home and work environments pose the most threat to the development of disease clusters. In most cases, as seen with workers who dealt with asbestos on the job, an entire group of individuals will report similar symptoms and progress with disease at the same rate as others.

  Pre-existing heredity and health conditions can expedite the disease process or lead to poor prognoses. "Environmental Health Perspectives" notes that epidemiologists, or those that study disease in populations, collect information regarding type of exposure, pollution sites, and data related to known chemical contaminants in the area to determine whether a disease is caused by an environmental factor.

Lifestyle Factors

• Diseases can also be attributed to lifestyle factors. For example, the early 1980s saw an increase in pneumonia cases among homosexual men. Researchers first attributed this outbreak to what was coined "gay cancer." Yet further investigation led to the discovery of human immunodeficiency virus and acquired immunodeficiency syndrome, also known as HIV and AIDS. According to the National Cancer Institute, the phenomenon gave birth to data collection that would later indicate that while not all cases involved homosexual men, the exchange of infected bodily fluids led to the clustering effects.