Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) is seen to be a major killer disease across the globe with increase of people getting infected daily. AIDS is the abbreviation for the acquired immune Deficiency Syndrome which is a condition representing the most serious and often fatal illness resulting form Human immune Deficiency virus (Cusack and Singh 1994).
The pandemic is still an emergency and long term issue since it developed over 30 years ago this means that in order to control and reduce the rate of transmission it will require and exceptional response that remains flexible creative and energetic. (UNAIDS 2004).
This essay will focus on the contribution epidemiology has made to the understanding and policy response of HIV/AIDS using different theoretical approaches, evidence from reports such as prevalence rate, incidence rate, mortality rate and the purpose of epidemiology as well background information. This essay will also highlight background information on biological, nutritional, social and life course Epidemiology for the study on HIV/AIDS.
There are two major types of HIV, which are HIV-1 and HIV-2. HIV-1 Virus is the predominant AIDS related virus and HIV-2 is a genetic but biologically different second type of AIDS related virus. (Pratt 2003). Since the epidemic began there have been initiatives introduced by the government with the contribution epidemiologist has made to investigate the number of people exposed to the virus, the cost needed has increased over years as to provide the necessary resources to where it’s needed efficiently.
In the twenty first century Epidemiology was drawing on conclusions from biology and sociology to biostatistics and philosophy of science which investigates the causes of human disease and their methods for their control (Yarnell 2007). Moon et al (2000) defines Epidemiology as the study of patterns of disease occurrence in human populations and the factors that influence these patterns. In contrast, Yarnell (2007) highlights that Epidemiology adopts a population approach to the study of the distribution and determinants of disease.
Importantly, epidemiology studies are designed to investigate the causes of disease and its attempt to measure the level of disease in a population by prevalence and incidence rate. From an epidemiologist perspective, a disease may have a single entry which is bacteria or virus, or a combination of causes which have become so broad that epidemiologist have to work in different levels of diagnostic to come to a conclusion (Yarnell 2007). HIV is an infectious disease which can also be passed from mother to infant, for an infectious disease like HIV the infectious agent is clearly a factor necessary for the development of the disease, such factor is known as the necessary cause (Yarnell 2007)
A group of factors work together to produce multiple causes of HIV/AIDS therefore it is the role of the epidemiologist to analyse as many causal factors as possible to determine their contribution to the development of the disease (Yarnell 2007). AIDS is not a new disease since its first case was diagnosed in 1981; it began to increase rapidly and since then the world has introduced initiatives and new ways of tackling this deadly virus by using different epidemiological approaches to understand HIV/AIDS and the prevention of the disease.
In the early decade of the epidemic, the only sources of data available at that time for assessing the epidemic were national AIDS surveillance registries which was established in the 1980’s, mainly in North America, Europe, Australia, and other developed countries but over the last three decades the approaches used for assessing HIV/AIDS has expanded given a more understanding as to why HIV/AIDS occur (Brookmeyer 2010)
The HIV prevalence is the number of people in the population suffering from a disease. World Aids Day progress report 2011 illustrates that a total of 27 million people acquired the HIV infection in 2010 down from 3.1 million in 2001 contributing to 34 million people living with HIV as of 2010, other statistics includes 2.7 million newly infected Adults and Children with 0.8% prevalence rates and 1.8 deaths due to aids. Amongst those infected it is said that 97% are in low and middle income countries with 1000 children under 15 years of age and 6000 Adults aged 15years and older of which 48% are women and 42% young people aged 15-24 years old. (World Aids Day progress report 2011)
As mentioned before HIV/AIDS is a major health problem in Sub-Saharan Africa were this deadly disease is most intense where it is estimated that 22.9 million adults and children living with HIV/AIDS and 1.2 Adults and child deaths due to AIDS. (World Aids Day report 2011). It is said that another virus relating to HIV has emerged which called HIV-2 which is found in African countries like Senegal and Ivory Coast, where the disease probably spread through the immigration of sex workers within the urban areas (Villarreal et al 1994). In contrast to this epidemiologist highlights that only in Africa that HIV is generalised with nearly the same number of men and women suffering from the disease. (Marum et al 2002).
Furthermore, whilst the number of adults and children infected with HIV and AIDS is increasing rapidly in other continents of the world such as Asia, there is an increase of HIV infection amongst commercial sex workers and drug users in India (Villarreal et al 1994). According to Word Aids Day report (2011) statistics shows that 4.0 million adults and children from south and south East Asia are living with HIV with Adult prevalence of 0.3% and Adult and child death due to AIDS was 250,000, In East Asia the figures of adult and children living with HIV was 790,000, with adult prevalence of 0.1% and 56,000 death due to AIDS as of 2011.
HIV in USA is another country increasing with the infectious disease, World Aids Day report (2011) statistics showed that there are 1.5 million adults and children living with HIV in North America with Adult prevalence of 0.6% and 20,000 deaths of Adult and child due to Aids. This statistics also reported that there are 1.5 million Adult and child in Latin American currently living with HIV with 0.4% Adult prevalence rate and 67,000 deaths of adult and child due to AIDS as of 2011.
It is estimated that 100,000 people in the UK will be living with HIV by 2012 and 45% of new diagnose was gay and bisexual men which seems to be the highest people in the UK suffering from HIV. (THT bulletin 2011)
Socio medical approach to health has been one of the approaches used to understand the social causes of health. Wall and ottewill (2004) states that Socio medical model of health results from complex and interactions within the social, economic, environmental and personal factors. Similarly, Social epidemiology is a branch of epidemiology that studies the distribution of health outcomes and their social determinants (Celentano et al 2004). These determinants are not just bacteria or biological but they are concerned with the way the structure of the society influences a person’s position to illness. (Moon et al 2001)
For an infectious disease like HIV, social epidemiologists investigates how the individual is exposed to the risk factors and under what social conditions factors are related to HIV. Recent literature search conducted by celentano et al (2004) identified four categories of social level factors relating to the cause of HIV/AIDS, these factors includes social network, neighbourhood effects, social capital and cultural context. In this article it highlights the role these determinants play in affecting one’s health.
In contrast, individual determinants do play a role in transmission of disease. These determinants include high risk behaviour such as unsafe sexual and drug injecting practices which are the major transmission for disease like HIV. Many of these conditions occur due to environment in which people grow, socialise and work and poor living conditions (Fenton et al 2010). Furthermore Cusack and Singh (1994) illustrates that approximately 75% of all infections were sexually transmitted with a heterosexual to homosexual ratio of 7:1. However outside Africa, the HIV epidemic affected gay men and injected drug users in North America and Western Europe as well as homosexuals, Haitians, heroin addicts (Donoghoe et al 2006)
A discussion paper 3 for the public health agency of Canada discusses the social determinants of health and HIV/AIDS within North America and highlights determinants such as poverty, health and wealth, socio economic areas, discrimination, ethnicity and gender. (Public Health Agency 2006).
In contrast to this Tladi (2006) discusses the empirical links between poverty and HIV/AIDS using a data collected by the 1998 South African Demographic and Health Survey. This study identified that there is a risk of HIV infections amongst poor people due to lack of knowledge and education as well as poverty related problems. The researcher analysed the results by using a probability sampling of 12,000 women who are aged between 15 and 19 years old. This study showed that the people who lived in deprived areas were not likely to use condom during sexual activities, not having full knowledge about the precautions of not using condom. However this study had an implication because of the year the data was collected through self-report as there could be an increase of bias and also any attempt to reduce HIV/AIDS should consider poverty being one of the social causes Tladi (2006)
Other social factors include the economic and social conditions that affect the health of the population in a community as a whole as well as education, health services, food security, access to services and housing. (Fenton et al 2010)
Other approach used to understand the causes of illness includes the bio medical approach to health which focuses on the biological components of the body. Wall and ottewill (2004) highlights that biomedical model of health emphasises on the biological causes and manifestations of disease and ill-health. This biological cause includes virus, bacterium, germs and internal faults in the body. Similarly to this, Villarreal et al (1994) illustrates that HIV is a type of virus called retrovirus which binds itself to the surface of an uninfected cell which then multiply to affect other cells in the body. These retroviruses that cause AIDS are grouped into two forms called lentiviruses and HTLV-BLV which are extremely important as they cause human disease (Pratt 2003).
Another branch of epidemiology that is important within the study of disease in a population is nutritional epidemiology which studies the relationship between diet and health in a human population (Byers 1999). This approach is extremely important because of the role it plays in investigating nutritional needs as well assessing the dietary requirements of the people suffering from the disease. However there have been issues with measuring diet intake in large populations which can result in measurement error. An article by piwoz (2004) discusses how the effect of malnutrition begins to take place once the individual becomes infected before the infected person is aware. This article also discusses how other studies showed how the risk of death was higher in HIV-positive adults with compromised micronutrient intake or status.
Nutritional assessment tools have been one of the techniques which epidemiologist uses to assess the dietary intakes on people suffering with HIV and AIDS. A study by Smit and Tang (2000) accessed the nutritional intake of injected drug users with HIV/AIDS using food intake tools. These intake tools included food records, 24 hour recall, food frequency questionnaire, dietary history and measuring the body components. These tools were used to monitor the food intake and nutritional status of the infected person. However There have been issues as to what tools is the best method to access the nutritional intake of those suffering from HIV because of the lifestyle and the influence on the disease, these issues includes the use of the right tools to access dietary intake and the need to develop more effective and modified tools and improving old tools for targeting the population.
Kuh et al (2003) highlights that a life course epidemiology attempts to incorporate biological and social risk processes rather than draw false contrasts between them. In this article it highlights the role the epidemiologists play in understanding the causes of illness from a life course perspective. This branch of epidemiology also studies how socially patterned exposures during childhood, adolescence, and early adult life influence adult disease risk and socioeconomic position (kuh et al 2003).
A report by Loewenson et al (2007) discusses the household impact of aids, using a life course approach analysis. In this report, it highlighted the life course determinants of health through different life stages which is likely to cause an individual suffer from infection. These determinants include limited access to health services, sexual violence amongst women, and risk of mother to child transmission, poor nutrition, stigma and social exclusion.
However, there seem to be a limitation with using a life course approach due to researchers focusing more on infant life and psychosocial theories on social epidemiology ( kuh and shlomo et al 2000) nevertheless it has provided meanings as to what factors affect the health and contribute to disease within lifespan development. Other researchers Loewenson et al (2007) argued that poverty is a big challenge especially for people living with AIDS in poor communities therefore this approach and planning for longer terms should not be a privilege on the wealthy but should focus more on poor people.
As mentioned earlier, the government have developed and introduced new initiatives in tackling the epidemic. Risk management guidelines have been established in Health care settings which allow health care providers dealing with clinical procedures follow strict guidelines issued by their employees for the transmission of blood Bourne virus. (Pratt 2003). The world health organisation department of HIV/AIDS provides support for the treatment, care and prevention services as well as drugs supply to ensure a comprehensive and sustainable response to HIV/AIDS in countries suffering from the epidemic. (World health organisation 2011)
In 2011 WHO adopted a new Global health sector strategy for the next five years which included addressing inequalities and human rights, build strong and sustainable systems, Optimize HIV prevention, diagnosis, treatment and care outcomes and Leverage broader health outcomes through HIV response. Within these strategies it included target and goals that need to be met within the next five years. (World Health Organisation 2011)
As part of the Global health challenge to tackle the affliction of the disease, WHO released an updated policy on collaborative HIV activities in 2011 which was based on trials, observation research and best practices which have been conducted and gathered for implementation and in response to demand from countries for immediate guidance on actions with regards to human immunodeficiency virus. (World Health Organisation 2012)
Epidemiology studies have identified risk behaviours of high risk groups such as unprotected sexual intercourse which have led to the development of public health measures and safe sex guidelines (Villarreal and Conner 1994). In 2001, the department of health released the national strategy for sexual health and HIV implementation action plan which includes reducing stigmas associated with people infect with HIV, improving the health of the people living with Aids as well as reducing the Transmission of Aids and STIs. (Department of health 2002) However, this document did not meets its target to reduce HIV transmission by 25% in 2007 therefore the National Aids Trust recommended that new targets for HIV prevention should be addressed both nationally and locally. (Parliament office 2007)
The department of health is working to reduce the number of HIV transmission. The department of health UK (2005) released a publication of policy response in integrating the national strategy for sexual health and HIV with primary medical care contracting. In this document it highlighted the ways in which different PCT’s can work together to promote and improve the sexual health of the population. (Nichol 2005)
In china, the government has strived to control the spread of HV/AIDS and decrease the prevalence to 30% by 2015 by devising an Aids Action plan target for five years. This plan outlines some of the major key issues such as targeting the AIDS public education, high-risk group intervention, HIV tests and treatment for people suffering from the disease. (English.news.cn 2012).
In 2001, The European Union implemented a programme for action against HIV/AIDS, malaria and tuberculosis in the circumstance of poverty reduction. (Piot and seck 2001) Elsewhere in Africa, in 2001 the president of Tanzania launched the National HIV/AIDS policy which includes the provision for antiretroviral therapy for all people living with HIV/AIDS (world health organisation 2005). In 2004 The White Paper Choosing Health, funded more money to sexual health which was allocated to Primary Care Trusts however charities argued that the primary care trusts are not given enough attention to areas that have high prevalence rates of HIV in order to prevent more people contacting the disease. (Post note 2007)
However For people who are aware of their health status, more attention is needed to ensure they can register in health service and receive antiretroviral therapy (Progress report 2011). Furthermore Government organizations must be strengthened to ensure comprehensive, translucent and accountable leadership.
Measures have been taken to limit the risk of mother to child transmission through breast feeding by giving pregnant mothers antiretroviral drugs to help prevent mother to child transmission of HIV thereby giving mothers hope to feed their baby safely (World Health Organisation 2011).
Different countries have already introduced approaches, which include public campaigns, mobile testing, workplace testing and home- and school-based testing (Progress report 2011) these testing makes it possible for services to be provided to communities or known people who is infected with HIV. (Progress report 2011)
In conclusion, HIV/AIDS is a global epidemic which is increasing rapidly in Africa where it is said to have the highest number of people living with the disease without any cure. Although various researches has been carried out using different approaches to understand HIV/AIDS, there are still gaps within the research and the need to carry more studies in HIV/AIDS from a life course perspective to give more in depth as to how an individual becomes infected. However epidemiologists have made a massive contribution to the understanding of HIV/AIDS using different epidemiological approaches such as social, biological and nutritional. Some studies carried out over the last 30 years since the birth of HIV/AIDS has given the us insight as to how the epidemic has increased within the years Therefore it is extremely important that the government continue to develop new initiatives in order to tackle this global epidemic.
Previous initiatives introduced by the government such as HIV testing, promoting safe sexual practices by giving out free condoms in GUM clinics, awareness campaigns have helped limit the risk of passing the infection onto to others. Furthermore more research needs to be carried out in nutritional epidemiology by taking account into people who live in poor deprived areas and creating more advanced for tool for accessing dietary intake.
Despite all the measures that have been taken to limit the spread of the deadly virus, Government still need to ensure that there is adequate supply of treatments available for people suffering with HIV. Public health policy makers must be developed amongst different health services to tighten referral systems so that people suffering from HIV can have the opportunity to access each service and finally safer sex practice and guidelines will need to be established as it’s one of the options of limiting the risk of transmission to others.
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JENNIFER EZEABASILI P10552871