Why is infection a problem?

According to the World Health Organization (WHO, 2017a) in 2015, infections made up 3 of the top 10 global causes of death. Of an estimated 56.4 million deaths during that year, 7 million (12.4%) were due to either lower respiratory infections (eg pneumonia), diarrhoeal diseases (eg cholera), Tuberculosis or HIV/AIDS (WHO, 2017a).

Infectious diseases do not necessarily have to be deadly to be devastating. Poliomyelitis (polio) rarely caused death, however, it caused permanent paralysis and disability.

Economic and social impact

Infectious diseases can have devastating economic and social impacts. Being ill can incur costs directly via healthcare as well as costs due to lost earnings and productivity at work (Hansen, Zimmerman, & van de Mortel, 2017). The 2019 coronavirus outbreak is already having substantial economic impacts globally due to disrupted trade and travel.

Low-income countries struggle much more with infectious diseases than high-income countries. According to the World Health Organization fact sheet in low-income countries, infectious diseases accounted for 5 of the top 10 causes of death, resulting in a total of 259 deaths per 100,000 population (WHO, 2017a). For high-income countries, however, infectious diseases accounted for 1 of the top causes, resulting in only 38 deaths per 100,000 population (WHO, 2017a).

Why do low-income countries experience higher infectious disease rates?

Financial limitations result in poor infrastructure, limited supplies and equipment as well as insufficient education. Poor infrastructure may consist of limited housing capabilities leading to overcrowding – a major infection transmission risk. Poor infrastructure may also result in a lack of access to clean water.

Water acts as a reservoir for many infectious agents so proper sterilisation techniques are essential for preventing transmission.

Shortage of equipment and knowledge leads to insufficient infection prevention and control (IPC) techniques, increasing the risk of transmission. Because of this, many infectious diseases seldom seen in high-income countries are considered to be endemic (constantly present in a particular region) in low-income countries. Tuberculosis (TB) for example, is one of the top 10 causes of death in low-income countries, even though it is treatable.

Efforts to control infectious disease

IPC protocols have been instrumental in controlling infectious diseases and saving lives. Poliomyelitis and smallpox are caused by viruses and have infected humans for thousands of years. Now, thanks to the creation of vaccines, as well as massive global efforts to implement IPC protocols, smallpox has been declared eradicated, and polio nearly so.

However, polio is still endemic in Afghanistan, Nigeria and Pakistan. Severe consequences could arise if polio is not eradicated in these areas. In just 10 short years, there could be as many as 200,000 new cases globally (WHO, 2017b).

Challenges

For all of our success in controlling and even eradicating some infectious diseases, others are emerging or re-emerging. Many difficulties arise when combating infectious disease, such as:

• genetic changes in the infectious agents themselves resulting in increased resilience and virulence (the ability to infect or damage the host)
• our ever-expanding population and movement
• deforestation and development have resulted in numerous outbreaks of unknown diseases due to exposure to previously isolated infectious agents
• the ability to travel vast distances in a short duration (particularly plane travel) have resulted in numerous disease outbreaks (epidemics), and from there escalating to pandemics (worldwide epidemics) much more quickly and easily than in the past. After all, it can take just one infected person to board a plane and bring their infection to a new area.

References

Hansen, S., Zimmerman, P., & van de Mortel, T. (2017). Assessing workplace infectious illness management in Australian workplaces, Infection, Disease and Health, 22(1), 12-20.

World Health Organization (WHO). (2017a). Top 10 causes of death. Retrieved from http://www.who.int/mediacentre/factsheets/fs310/en/

World Health Organization (WHO).(2017b). Poliomyelitis. Retrieved from http://www.who.int/mediacentre/factsheets/fs114/en/