Wednesday 7 December 2016

Cholera, the disease of the poor


Cholera is an infectious disease caused by the ingestion of the Vibrio cholerae strain of bacteria that affects the small intestine. Transmission can occur via faecal-oral contamination or consumption of contaminated food or water. The symptoms include diarrhoea, vomiting and muscle cramps, resulting in severe dehydration and organ failure. Diarrhoea causes 11% of child deaths globally – more than AIDS, measles and malaria combined (Liu et al. 2012). The disease ‘no longer poses a menace to countries with minimum standards of hygiene’, but continues to be problematic in places that lack clean water and sanitation coverage (Talavera and Perez 2009: 408). While rich countries face practically no cases at present, serious outbreaks in less economically developed countries are still occurring regularly. Is the prevalence of cholera determined by economic prosperity (i.e. GDP per capita)?

Outbreaks of cholera can be seen throughout the past centuries across the world. In London during the 1850s there was a cholera outbreak in Soho, which was found by Dr John Snow to be an issue of the interconnected wells which provided people with contaminated water. Today, cholera has been eradicated in the UK, yet African countries reported 3,221,050 suspected cases from 1970-2011, and worldwide (excluding Haiti) in 2011 sub-Saharan Africa accounted for 86% of cases and 99% of the deaths from the disease (Mengel et al. 2014). Mali, with a GDP per capita of $2200 in 2015 (CIA World Factbook), has seen thousands of cases and deaths in the past decades (Figure 1) – and these are just the ones recorded and reported to the World Health Organisation (WHO). According to Talavera and Perez (2009), nearly all low income countries experience cholera outbreaks, whereas the proportion of the high income countries group was 30 times lower (see Figure 2). In these countries, the high rates of poverty indicate a lack of financial capacity, both by the state and by individuals, to provide safe water, waste management infrastructure and other sanitary resources, which are the main causes of easy spread of the disease.These features in fact act as preventative measures against cholera. The authors found that the variable that contributes most to the sudden incidences of cholera is the proportion of households without tap water; other factors that correlated positively with cholera were low household incomes and lack of sewerage systems. In Mali, 3.7 million people do not have access to safe water (Water Aid 2016). 
Fig.1 Officially notified cases & deaths to WHO 1970-2008. Source:WHO

Widespread poverty means that cholera in some countries is often fatal, a much more severe and dramatic result than those in high income countries. Cholera mortality, which is non-existent in the latter group, is 2.3% in low income countries (Talavera and Perez 2009). In Mali, for example, during the outbreak in 2005, 158 cases were reported from 20th June to 24th July, including 20 deaths, which signifies a case fatality rate of 13% (WHO 2005). GDP per capita here is also clearly linked in the sense that patients would be able to afford (better) medication or education that would have improved their health literacy.

Fig. 2 Percentage of countries reporting indigenous cholera cases in each group (income per habitant). Source: Talavera and Perez 2009


So far I have practically assumed that it is down to individuals to implement measures to control the prevalence of cholera. Yet, the state has a role to play when it comes to such an important matter of public health; one cannot simply expect individuals to have access to the credit needed to pay for large water or sewerage infrastructure projects. The Malian government spends under 7% of its GDP on health, and GDP is just $36 billion (CIA World Factbook). To give this some perspective: the UK spends the equivalent of 325% of Mali’s total GDP on the NHS (King’s Fund 2016). There are 8 doctors per 100,000 people. This demonstrates that medical attention is very difficult to access, particularly in rural areas, and simple cholera treatments like oral rehydration solutions (ORS), which prevent serious dehydration and electrolyte imbalances in the body, are not distributed quickly to those who need it.

In some of the worst cases, much of the governance and policies on cholera control are acted upon by international bodies and non-governmental organisations (NGOs) instead of the state. The WHO, UNICEF, Doctors Without Borders and other NGOs have extensive operations in Mali, particularly in the more neglected northern regions. In the Gao region, Doctors Without Borders staff work in health centres in rural areas to arrange medical referrals, and support hospitals with outpatients, maternal health and surgery. In 2012, to curb yet another cholera outbreak, over 70 tonnes of relief supplies were flown to Mali, including water purification supplies for over 28,000 people, emergency medical kits for 25,000 people and ORS to help 2 million people. This list consists of just UNICEF and AmeriCare’s contribution (InterAction 2012).

Another obstacle that makes governance and cholera control more challenging is its prevalence in neighbouring countries. Lack of sanitation in adjacent states can mean spread of cholera through contaminated surface water that flows downstream in trans-boundary rivers, as well as via movement of people or trade. In Ghana, another West African country, cases of cholera incidence rates are highest along the coast (where most trade with neighbouring countries arrives) and in the north near the border with Burkina Faso (which also borders Mali). UNICEF recommends ‘strengthening early detection’, ‘coordination mechanisms across the sectors and borders’ and ‘building capacity on outbreak management’ (UNICEF 2016). This means that cooperation between states – e.g. disclosing information about outbreaks and their geographical distribution immediately – and collaboration on preventative measures is needed to effectively control cholera. The management of cholera outbreaks in reality is not confined to national boundaries and must be an international effort.

For Mali, the prospects of tackling cholera look grim; long term solutions seem difficult given the current financial constraints of the government and violent conflicts in parts of the country. With average adult literacy below 40%, achieving widespread health literacy and awareness of hygienic practices that will reduce the severity of cholera incidents is extremely challenging (CIA World Factbook). Large infrastructure projects to provide clean water and dispose of waste are costly, while security issues and high poverty rates (translating to low ability to pay) act as deterrents for the private sector to enter the water and sanitation industry. It may not be the case that cholera is a disease of the poor, but rather a disease of poor governance. 

4 comments:

  1. Hi Ana. I found your post quite interesting. I hadn't considered that neighboring countries' sanitation practices would affect another population's disease rate, but it makes total sense. Thanks for bringing up this point.

    ReplyDelete
  2. Hi Ana-Lin,

    I’ve enjoyed this post and the others leading up to it.

    In my blog, one of the main concerns is whether disparities between Sub-Saharan Africa and more developed regions across the world are going to widen, or whether this age of rapid urbanisation can bring with it solutions and opportunities. For this reason, we have similar concerns. Thus, I would like to know the answer to the question you posed in your blog: ‘Is the prevalence of cholera determined by economic prosperity?’

    Robert

    ReplyDelete
  3. Hi Rob,

    Thanks for your question. It is important to first state that in my post I refer to economic prosperity in terms of GDP per capita.

    The paper by Talavera and Perez (2009) shows a strong correlation between economic development and cholera. It is very clear that their sample of high income countries have much lower morbidity and mortality rates of cholera compared to their group of low income countries. However, they also conclude that other characteristics like the 'environment, climate, culture, medical management, political intention' affect cholera incidence and its spread.

    To answer your question simply: no, prevalence is not determined by economic prosperity. This would be equivalent to stating that good governance is determined by GDP per capita. Economic factors (GDP per capita, government funds, taxation revenue etc) have a major role to play in the issue of cholera, but a direct causation cannot be isolated.

    ReplyDelete
  4. Fascinating post Ana-Lin - particularly the part about adjacent states (and their downstream rivers) affecting cholera rates. Another factor that is out of any individual state's hands is climate change, with a recent study showing that a warming trend in sea surface temperature is strongly associated with the spread of cholera (http://www.pnas.org/content/113/34/E5062.abstract). The spread of cholera is certainly not confined to national boundaries, so like you said: our management of the disease can't be either!

    ReplyDelete