Tuberculosis is a very serious infectious disease that primarily affects the lungs, causing cough and breathing difficulties. The infection also causes systemic effects including fever, night sweats and weight loss (Ellner, 2011). In some cases, the infection can spread beyond the lungs and affect the bone/joints, lymph nodes, abdomen and blood stream (Ormerod, 2003). The disease is caused by the bacteria mycobacterium tuberculosis (WHO, 2014), which is spread through respiratory droplets. These droplets are passed when an infected individual coughs or sneezes and the droplets become inhaled by another person (NHS, 2014). Despite this easy method of transmission, tuberculosis is not readily transmitted, and therefore is most likely to affect those in close contact such as family or household members (Castillo-Chavez & Feng).
Tuberculosis represents a significant risk of morbidity and mortality and represents a significant cost to society to treat and manage. Tuberculosis has particularly shown to be a problem in cities, whereby the rates of increase are greater than those of rural areas (Anderson et al. 2006). This essay will address the reasons as to why tuberculosis affects urban areas (the sick city hypothesis), and look in to why tuberculosis contributes to this urban health penalty.
As an exemplar of an urban suffering from the burden of tuberculosis, this essay will focus on the London borough of Newham. Newham has a tuberculosis rate 8 times higher than the national average and 3 times that of London. This essay aims to investigate the aetiology behind the incidence, and to find ways of reducing the rates of tuberculosis among individuals in the London borough of Newham. The paper will include the intervention strategies and how they should be implemented in order to reduce the rates of new infections and encourage men to get tested and get early treatment before the spread of infection.
2.Tuberculosis in an Urban Environment
Tuberculosis tends to be regarded as a problem of the past, and was responsible for 20-30% of all mortality in 17th-19th century Europe (Dye & Williams, 2010). The incidence of tuberculosis declined throughout the 20th century (Watson & Maguire, 1997), however, the disease has been slowly returning to London since the 1980’s (Great Britain 2008, p. 19). The problem seems to be worsening in urban areas. This is illustrated by the example of London, where 3,302 new cases of tuberculosis (TB) were reported in 2010 (Fullman & Strachan 2013, p. 25), a figure that has more than doubled since 1992 (Anderson et al 2006). In 2006, the incidence of tuberculosis in London was 41.5 people in 100,000, a figure that represented the highest number of new cases in any major city in Western Europe (Anderson et al, 2006). Dyer (2010, p. 34) claims that the London borough of Newham is the most affected with some people already referring to it as the TB capital of the affluent western world. In fact, the rates of tuberculosis in Newham are currently higher than that in some impoverished countries. Vassall (2009, p. 48) suggest that Newham has 108 cases per 100,000 and Anderson et al suggest a 2001 figure of 116/100,000, figures that are more than half that in India (174 cases per 100,000) (Public Health England, 2012).
Newham has a population of 308,000 with a population density of 85.1 per hectare as compared to 31 in central London (UK Census, 2012). These figures suggest that even in the populated city of London, Newham is an area of urbanisation, with a large number of people concentrated into a relatively small area.
The increase of tuberculosis has been described as a ‘penalty for high density urban living’ (Dye 2010, p.859), likely due to the increased potential for transmission in overcrowding, and the increased rates of immigration to inner-city areas. Bhunu and Mushavabasa (2012) propose that tuberculosis thrives in conditions of overcrowding and poverty, issues that are common in urban areas.
The high rates of tuberculosis in cities such as London, and areas of urbanization such as Newham, suggest that the incidence of tuberculosis is indeed an urban issue. Newham fulfills the criteria of high immigration rates and being an area of deprivation..
Newham has a diverse ethnic population, with 61% of the people being non-white (Farrar & Manson 2013, p. 54). The population of ethnic minorities continues to grow along with the increasing numbers of refugees and asylum seekers in greater London.
Another aspect of urbanisation illustrated in the borough of Newham is that of deprivation and overcrowding. Farrar & Manson (2013, p. 16) claim that Newham ranks as the third most deprived borough in inner London. Most of the people here live in tower housing and overcrowded conditions that are the perfect condition for the spread of tuberculosis. There is a positive correlation between poor housing and poverty and the prevalence of tuberculosis, which is very clear in Newham as evidenced by the findings of 108 and 116 cases per 100,000 people (Vassal, 2009; Anderson et al., 2001). The aetiology of the issue of tuberculosis is highlighted when considering the distribution of the disease across Newham. The occurrence of disease is not evenly spread across the borough, with 70% of cases coming from Manor Park, Green Street and East Ham. These boroughs represent areas of population increase, overcrowding and higher levels of those living in poverty. Manor Park and Green Street also show differing dynamics of tuberculosis incidence, representing an overall increase of 40% since 2006 whilst all other areas of Newham either remained static or showed slight decrease (Malone et al 2009, p. 23).
It can be seen that tuberculosis presents a significant urban issue, especially when comparing incidence in an urban area such as Newham to those less urbanised areas. Bromley has a population of 309,000 and a population density of 20 per hectare, in comparison to Newham’s population density of 80 per hectare (UK Census, 2012). Tuberculosis incidence in Bromley is between 0-19 per 100,000 compared to that of Newham, which is five times greater at 80-100 per 100,000 (Anderson et al., 2006).
It is for this reason that necessary intervention strategies need to be formulated and implemented to help reduce the rates of tuberculosis among individuals living in Newham.
3. The Influence of Urbanisation on Tuberculosis Incidence
While the global rates of tuberculosis are declining, the disease is showing steady increase in the United Kingdom. In 2012, 8751 new cases of the disease were identified in the country with 39% coming from London (Fullman and Strachan 2013, p. 43). Indeed London has the highest rates of the disease in Western Europe with Newham borough having the highest rates in the UK. Jindal (2011, p. 55) claims that the rate of tuberculosis in some London boroughs is more than twice higher than the threshold used by the world health organisation to define high rates. These higher incidences support the notion of a sick city hypothesis where there are greater levels of ill health than in rural areas, and may be due to the presence of factors in an urban environment that contribute to ill health (an urban health penalty).
One factor that may contribute to the urban health penalty is that of immigration. Cities are easier to access than rural areas, provide areas of congregation and provide more facilities for immigrating families and individuals. The majority of individuals suffering from tuberculosis are people born outside the United Kingdom, with 75% of cases in 2003 being born abroad (Anderson et al., 2006). A reason for the high incidence in those born abroad but now living in the UK is exacerbated by the nature of tuberculosis. On initial infection, tuberculosis is confined by the immune system with only around 5% of cases experiencing symptoms within the first two years of infection (Narasimhan et al., 2013). The remainder of cases harbour a latent infection which may reactivate later in life, with about 10-15% of those infected going on to develop an active disease (Narasimhan et al., 2013). This insidious nature combined with the later activation of the disease explains why many people do not get the disease until later in life. It is likely that it is contracted in their country of birth, however then manifests much later once they have moved to the UK.
Statistics indicate that over 90% of the residents in Newham diagnosed with the disease in 2011 were born outside the United Kingdom (Fullman and Strachan, 2013, p. 33). Among these, 50% arrived in the country in the last five years. In the same year tuberculosis diagnosis increased by 25% compared to 2010 (Fullman and Strachan, 2013), possibly as a reflection of the increased immigration.
Additionally to a high immigrant population bringing significant disease burden from their countries of birth, London and Newham both represent many of the other issues of urbanisation and urban health penalty that can contribute to the high incidence of tuberculosis.
Studies have shown that low vitamin D levels are associated with an increased risk of developing tuberculosis (Campbell and Spector, 2012; Chan, 1999). This is an important association in urban populations, as the living and working conditions foster less access to sunlight (the major source of vitamin D). Additionally, Asian immigrants present a problem of low vitamin D due to vegetarian diets, and a tendency to cover up their skin, not allowing to take advantage of the small amount of sunlight available (Chan, 1999). As previously mentioned, Newham is an area of both high urbanisation and with a large immigrant population, and 38.6% of the population being of Asian descent (London Borough of Newham, 2010).
The immigrant population of urban areas such as Newham also present a non-vaccinated proportion of society. Whilst the BCG vaccine against tuberculosis was introduced in the UK in the 1950s and was shown to provide a reduction in risk of contracting tuberculosis (Colditz et al., 1994), those immigrating were less likely to receive this vaccination on moving to the UK.
London also represents cases of tuberculosis that are socially and medically complex. As a hugely populated area, London includes those with HIV infection and presents other risk factors such as onward transmission and poor treatment. HIV is one of the most powerful risk factors for tuberculosis, with a incidence rate of 20 times higher in those that are HIV positive (Dye and Williams, 2010). People’s attitudes towards and access to healthcare also present a complex mix of factors which contribute to an increased incidence of many health problems, including that of tuberculosis. Those in impoverished areas have reduced access to healthcare, which may stem from many reasons such as complex needs, chaotic lifestyles, location of services, user ignorance, and language and literacy barriers (Szczepura, 2005). These can affect the disease process of tuberculosis from prevention, treatment of active disease, adherence to treatment and prevention of the health consequences.
Especially problematic are misconceptions and a lack of understanding of the disease, leading to late presentation and delayed access to treatment (Figuera-Munoz and Ramon-Pardo, 2008)
With the close living quarters in areas such as Newham, the spread of tuberculosis is facilitated. With poverty, poor housing and overcrowding, these areas concentrate several risk factors and lead to a greater spread of tuberculosis (Bates et al., 2004).
These determinants therefore suggest that the incidence of tuberculosis in urban areas is a complex issue. Controlling and preventing tuberculosis in London requires effective social and economic tools that must be incorporated in the development of policies of control in treatment initiation.
4. Consequences and implications of tuberculosis on the general population
Tuberculosis ranks with HIV/ AIDS and Malaria as one of the three main health challenges currently facing the world. The Commonwealth Health Ministers Update 2009 (2009, p. 41) indicates that 8 million new cases are reported globally each year. As previously mentioned, when combined with HIV, tuberculosis can prove lethal as the two diseases enhance the progress of each other. It is for this reason that tuberculosis is the major cause of death among HIV patients with the rate standing at 11% globally. The World Health Organization (2009, p. 27) indicates that tuberculosis is responsible for more deaths today than ever before, with approximately 2 million lives claimed by the disease annually.
As well as the significant mortality contributed by tuberculosis, the morbidity of the disease can be extremely detrimental both socially and economically. Those with the active disease that are not receiving treatment have been shown to go on to infect 10-15 others every year (WHO, 1998). Those who do receive treatment face a long (up to six months) and complex treatment regime involving several medication side effects. This can affect adherence to the treatment regime, and lead to the disease developing a resistance to the treatment, with this drug resistant tuberculosis contributing to greater mortality and increased expense to treat (Ahlburg, 2000).
As well as the significant morbidity and mortality, it is important to consider the economic impact of tuberculosis. The World Health Organisation estimated the cost to treat tuberculosis in 2000 as $250,000 US dollars (?150,000) in developed countries (Ahlburg, 2000). This presents a significant burden to the UK NHS, not to mention the time lost through not working which can dent the economy.
London is a global world trade centre whose economy is shaped by global forces, particularly in terms of trade, labour and capital. As a gateway to both the UK and other parts of Europe and the rest of the world, London records a very large number of tourists and immigrant populations. This high number of people accelerates the spread of the disease as people carry it to the country from other parts of the world is indicated by the new infection patterns and is highlighted by the prevalence in immigrant populations.
5. Strategies and intervention for addressing tuberculosis
Current UK guidelines for tuberculosis intervention were made by NICE in 2006 (updated 2011). The recommendations propose strategies for identifying those with latent (non-active) tuberculosis to prevent spread or reactivation and also specify criteria for treatment (NICE, 2011). Those recommended for screening for latent tuberculosis include close contacts of infected individuals, immigrants from high incidence countries, immunocompromised individuals, and healthcare workers. Whilst this strategy targets prevention of the spread of tuberculosis, they are only targeting specific groups, and it is likely in high incidence areas such as Newham, people will slip through the net. These guidelines have only changed minimally since 2006, and since then tuberculosis incidence has been on the increase in areas such as Newham, suggesting that changes may need to be made.
High incidence areas of the UK such as Newham could learn from New York experience and copy the strategy it used in dealing with the disease. With the implementation of broadened initial treatment regimes, direct observed therapy, and improved guidelines for hospital control and disease prevention, the city managed to halt the progression of an epidemic (Frieden et al., 1995). As mentioned in the previous chapter, adherence to the lengthy treatment regime as well as a lack of understanding may contribute to the spread of tuberculosis. Directly observed therapy (DOT) involves observing the patient take each dose of their medication, with outreach workers travelling to their homes. Evidence from New York showed that through DOT, only 3% of patients in therapy were infectious, compared to a proposed 20% if not receiving DOT (Frieden et al., 1995). Current UK guidelines (NICE, 2006) do not recommend DOT, although they do state that it may be used in cases of patients with previous issues with adherence or at high risk. Although an expensive and time consuming process, if DOT can reduce infectious cases, this would also work as a preventative measure. There could be one allocated outreach nurse for the borough of Newham and other high-risk areas.
Another method implemented in New York was the downsizing of large shelters for the homeless. These were breeding grounds for tuberculosis, and the subsequent reduction in overcrowding led to a decrease in transmission of the disease (Frieden et al., 1995). Whilst it is not possible to split people up from living with their families in crowded homes in terms of Newham, education about keeping those with tuberculosis from interacting with too many others in crowded conditions may be of benefit.
The model should also borrow from those used by other cities like Paris and the rest of Europe in controlling tuberculosis with intervention at the level of the agent, individual and community levels.
In Paris, Rieder (2002) suggested that prophylactic treatment could be used to prevent the disease occurring in those at risk, for example those in the household of an identified case of tuberculosis. Additionally, Rieder (2002) proposed that early or neonate vaccination be used especially in those in areas where tuberculosis is frequent, rarely diagnosed, and adequate contact examinations rarely feasible. It may be possible that in cases where lots of people are vaccinated that they may infer herd immunity and thus protect unvaccinated individuals from the disease. Once the populations have been protected and the incidence (number of new cases) of tuberculosis has been reduced, this allows for a reduction in the prevalence of tuberculosis (number of ongoing cases at any one point in time) with preventative chemotherapy that can treat sub-clinical, latent tuberculosis in the population. This preventative chemotherapy is likely to be extremely relevant to Newham due to the large immigrant population likely harbouring latent tuberculosis.
On a country- or city-wide scale, these recommendations from New York and Paris provide excellent models for preventing the increase of tuberculosis any further. It is also important, however, to consider the individual communities in Newham, and to promote health awareness and an attitude towards taking responsibility for their health. Their needs to be an encouragement at the level of primary care where immigrant populations feel that they can approach healthcare, and education to encourage tuberculosis prevention and adherence to treatment.
The strategy should be all-inclusive in order to encourage people to not only go for testing but also start and finish the treatment process.
6. Recommendations and conclusion
Tuberculosis presents an important urban issue in the area of Newham. Incidence is greater than other areas of the UK, and is over half that of India. There are several factors contributing to this including a large immigrant population, crowding and overpopulation, access to healthcare and comorbid health problems such as vitamin D deficiency and HIV.
The disease has considerable effect on morbidity and is responsible for high levels of mortality. Further consequences of the disease manifest as economic problems such as cost of treatment and loss of work.
London and the UK already have policies and structures for controlling tuberculosis in place; however the implementation process is patchy across the city, and often dependent upon budget. In high-risk areas such as Newham, there is poor access of healthcare due to inaccurate beliefs on the disease, language and cultural barriers, and complex needs of the population. In the case of tuberculosis, these contribute to poor disease prevention, delayed diagnosis and poor treatment adherence. All of which lead to an increase in transmission and health consequences. The area of Newham would benefit greatly from further education into tuberculosis, how to look for signs and how to get treatment. Encouraging good relationship with healthcare professionals and promoting access to healthcare through outreach programmes and targeting pharmacies may be helpful.
Additionally, Newham should look to employ techniques used in New York and Paris, including DOT, prophylactic treatment and neonate vaccination to reduce both the prevalence and incidence of tuberculosis.
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