Epidemiology of Communicable Disease - HIV Epidemiology of Communicable Disease

Description of the communicable disease (causes, symptoms, mode of transmission, complications, treatment) and the demographic of interest (mortality, morbidity, incidence, and prevalence).

Human immunodeficiency virus (HIV) is a virus that can lead to the development of acquired immunodeficiency syndrome, or AIDS, in susceptible people. Although the human body can eliminate some types of viruses, it cannot eliminate HIV, so once a person get HIV, they have the virus for life.

Within an organism, the HIV virus spreads via body fluids, affecting certain cells of the immune system. These cells are referred to as T cells or CD4 cells. As HIV moves through the body, such a massive number of T cells are destroyed that the body can no longer effectively fight off infections and other diseases. This is the point at which an HIV infection results in full-blown AIDS.

Although HIV presents with many symptoms, it is necessary to be tested for the viral infection to be certain of a diagnosis of HIV. Indeed, many people who have become infected with HIV are symptom free for many years -- numerous cases are absent symptoms10 years or more. Also, despite the potential severity of the disease, many people can only describe having experienced flu-like symptoms two to four weeks after being exposed to the virus. These people may describe their symptoms as seeming like "the worst flu ever." For others who fit a more conventional pattern, these symptoms are evident: Fever, enlarged lymph nodes, sore throat, and rash. Those who are aware of the symptoms associated with other viruses and some bacterial infections, will recognize that these symptoms are not distinct to HIV, which is another important reason for ensuring that anyone who presents with these symptoms -- and who may be at risk for getting HIV -- get tested for the presence of HIV. These symptoms can be present for a period of time that varies from just a few days to several weeks in duration. Importantly, a test for HIV infection may not show that HIV is present in the body during this early period, however, people infected with HIV can easily spread the disease to others because they are highly infectious at this time.

The mortality rate for HIV is high. Most people cannot be cured of the disease. Interestingly, most reports of people being cured of HIV involved treatment for a cancer that would have been terminal. The cancer treatments that have contributed to these HIV cures are very risky and are life threatening in and of themselves. So for this reason, physicians only resort to these cancer treatments when the HIV-infected people would have otherwise died.

The other type of treatment is referred to as antiretroviral therapy (ART). HIV-infected people treated with ART have had their lives dramatically prolonged as a result of the treatment. Successful ART regimens also provide the benefit of reducing the risk that HIV-infected people will infect others. To date, successful treatment has been shown to be most effective when the HIV infection is found and treated early -- an important reason for encouraging people who present with symptoms that could be HIV to get tested for the viral infection as soon as they suspect that they are ill.

The progression of HIV has been well documented. Without treatment, HIV is very nearly universally fatal as the action of the virus works steadily to eventually overwhelm the immune system until the condition known as acquired immunodeficiency syndrome (AIDS) results. Treatment has been shown to both slow and prevent the progression of HIV from one stage to another, thus treatment for HIV is believed to infected people at all stages of HIV.

HIV is so very infectious that it can be transmitted to others during any of disease stages: Acute infection, clinical latency, and acquired immunodeficiency syndrome (AIDS). The acute infection stage occurs within two to four weeks after the person has been infected with HIV, and the infected person may feel ill with symptoms that are similar to those experienced with the flu. The presence of symptoms during this stage is technically referred to as acute retroviral syndrome (ARS) or primary HIV infection. Not everyone who is infected with HIV develops ARS, even though it is the body's natural response to the viral infection. As is typical of a viral invasion of the body, during the early stage of infection, large numbers of HIV are produced within the body. The HIV uses the CDR immune system cells in order to make copies of itself, and in the process the immune cells are destroyed by the virus, resulting in a precipitous...

It is during this stage of very high levels of HIV in the blood that the virus is most easily spread to others. A healthy immune response will lower the amount of virus in the body, and the CD4 will increase although it may not return to the normal pre-infection levels.
The stage referred to as clinical latency is a period of dormancy or inactivity for the virus. The HIV is still active in the body, but it reproduces at a much lower level, so much so that the period is called asymptomatic HIV infection or chronic HIV infection. Many HIV-infected people don't get sick during this period and do not have symptoms. Currently, people who are actively undergoing ART may experience clinical latency for a number of decades. People who are not on ART may progress through this phase faster, though some will still experience latency for roughly up to a decade. ART treatment does not preclude the transmission of HIV to others, although it is viewed as greatly reducing the risk of transmission. During clinical latency, usually toward the middle or the end of the period, the viral load will again start to rise and the CD4 cell count will drop. Generally, this change is accompanied by symptoms of HIV infection and the immune system weakens to the point where it can no longer protect the HIV-infected person.

The advanced stage of the viral infection is AIDS, a point at which the immune system is so badly damaged that the person is vulnerable to other infections and cancers that are known as opportunistic illnesses that are infection-related. AIDS is diagnosed if the CD4 count drops below 200 cells per cubic millimeter of blood (200 cells/mm3). By comparison, normal CD4 counts fall between 500 and 1,600 cells/mm3. No matter what the CD4 count is, the presence of one or more opportunistic illnesses is also grounds for a diagnosis of AIDS. Once diagnosed with AIDS, people generally survive about 3 years without treatment. This life expectancy time is shortened to about one year if the person comes down with an opportunistic illness. Regardless, in order to prevent death, people who have AIDS require medical treatment.

Describe the determinants of health and explain how those factors contribute to the development of this disease.

The determinants of health include the social, economic, and structural aspects of societies. In addition, the physical environment or context in which people live is another important determinant of health. The individual characteristics and behaviors of people are inter alia important determinants of health. While individuals are unlikely to be able to directly control many of the determinants of health, HIV is directly related to a number of behaviors over which people can have control.

HIV is most commonly transmitted is through anal or vaginal sex or sharing drug injection equipment with a person infected with HIV. Substance use and abuse are important factors in the spread of HIV as drugs can lower a person's inhibitions and create or increase risk factors for HIV transmission. Vulnerable or marginalized populations (people who are impoverished, mentally ill, or have a history of abuse) are more likely to use and abuse alcohol and controlled substances. In addition to these risks, some attributes are specific to particular cultures and are particularly difficult to address. Very fundamental ignorance and superstitious beliefs about the nature and transmission of disease in general, and HIV specifically, cause people to continually expose themselves to the risks of HIV infection and AIDS.

Discuss the epidemiologic triangle as it relates to the communicable disease you have selected. Include the host factors, agent factors (presence or absence), and environmental factors.

The three elements of the epidemiologic triangle are: host, agent, and environment. Host factors influence the severity or the chance for the disease. Host factors include personal traits, behaviors, genetic predisposition, and immunologic factors. Agent factors are necessary for the disease to occur and include biological, chemical, and physical agents. Environmental conditions contribute to the disease process and include external biologic, physical, social conditions. The attributes of hosts discussed above play a pivotal role in the occurrence and transmission of HIV and AIDS.

Explain the role of the community health nurse (case finding, reporting, data collecting, data analysis, and follow-up).

In global HIV care, considerable task shifting or task sharing has taken place. Nurses prescribe medications without having ongoing referrals, interdisciplinary communication, or support from…