Introduction

Parasitic infections remain a significant public health challenge worldwide, particularly in low and middle-income countries (LMICs), where millions of people are affected annually.¹ These infections are caused by a variety of organisms, including protozoa, helminths (worms) and ectoparasites, which often have long-term health consequences. Socioeconomic status (SES) - a complex construct that includes education, occupation, income, food and housing security and access to resources - plays a pivotal role in influencing both the susceptibility to and the management of parasitic infections. Lower SES is consistently linked to a higher prevalence of parasitic diseases, more severe outcomes, and barriers to effective treatment.²

Socioeconomic status influences on susceptibility to parasitic infections

Poor living conditions and sanitation

One of the primary ways SES influences susceptibility to parasitic infections is through its impact on living conditions, particularly access to clean water and proper sanitation. Individuals in lower socioeconomic strata are more likely to live in environments where inadequate sanitation and unsafe drinking water prevail. These conditions create ideal environments for parasites such as Giardia lamblia, Entamoeba histolytica, and helminths like Ascaris lumbricoides (roundworm) and Trichuris trichiura (whipworm) to thrive. For instance, intestinal helminth infections are primarily transmitted through soil contaminated with human faeces, and poor sanitation directly correlates with the risk of exposure.

The lack of access to clean water exacerbates the risk of contracting waterborne parasitic infections like schistosomiasis, which is transmitted by freshwater snails carrying the parasite Schistosoma. These infections can become endemic in regions with poor water infrastructure. Additionally, the absence of vector control in low-income areas increases the risk of vector-borne parasitic infections, such as malaria, leishmaniasis, and Chagas disease, which are transmitted by mosquitoes, sandflies, and triatomine bugs, respectively.^3,4

Overcrowding and exposure

Living in overcrowded conditions, common among lower SES populations, also increases exposure to parasitic infections. Overcrowding facilitates the spread of parasites that are transmitted via close contact or shared environments, such as scabies, mites and lice. Moreover, the more densely populated an area, the more difficult it becomes to maintain proper hygiene and sanitation, further compounding the risk of parasitic infections.

In rural settings, where agriculture is often the primary source of income for low-income families, people are more likely to come into contact with soil-transmitted helminths through farming and irrigation activities. In urban slums, poor waste management and stagnant water make people more susceptible to vector-borne diseases. These living environments reflect the broader inequities that exist between different socioeconomic classes, illustrating how SES can significantly dictate an individual's risk of exposure to parasitic diseases.⁵

Nutritional status

Low SES is also closely linked to poor nutrition, which exacerbates susceptibility to parasitic infections. Malnutrition weakens the immune system, making individuals more susceptible to infections and increasing the severity of parasitic diseases. Children in low-income communities are particularly vulnerable to malnutrition-related immune suppression, which can lead to more frequent and severe parasitic infections.

For example, intestinal helminth infections, such as hookworm, can cause malnutrition by leading to blood loss and nutrient malabsorption. This creates a vicious cycle where malnutrition increases the severity of parasitic infections, and the infections themselves further worsen nutritional deficits. Similarly, malaria can cause severe anaemia, especially in children, further weakening their immune response and making it harder to fight other infections.⁶

Education and awareness

Education is another aspect of SES that influences susceptibility to parasitic infections. Populations with lower levels of education often have limited awareness of the modes of transmission and prevention of parasitic diseases. For instance, in many communities with low literacy rates, knowledge about the importance of handwashing, boiling water, and using latrines may be lacking. These preventive behaviours are critical in reducing the risk of contracting parasites, but without the appropriate knowledge, people are more likely to engage in risky practices.

In addition, misinformation and cultural beliefs surrounding parasitic infections may be more prevalent in lower-income communities with lower educational attainment. For example, in some regions, people may not recognise parasitic symptoms as being linked to an infection and instead attribute them to spiritual causes, delaying or preventing effective treatment.⁷

Socioeconomic status influences on management of parasitic infections

Access to healthcare

The management of parasitic infections is heavily influenced by SES, particularly through access to healthcare services. In many low-income areas, healthcare infrastructure is weak, with limited access to diagnostic tools, treatments, and qualified healthcare professionals. Even when healthcare facilities are available, individuals from lower socioeconomic backgrounds may face financial barriers that prevent them from seeking care. The cost of medical consultation, diagnostic tests, and medications can be prohibitively expensive, especially for those living below the poverty line. As a result, parasitic infections often go undiagnosed and untreated, leading to more severe complications and chronic illness.

In rural and remote areas, healthcare facilities may be few and far between, making it difficult for people to access timely treatment. This lack of access to care is particularly concerning for parasitic diseases like malaria, where early treatment is crucial for preventing severe outcomes. Delayed treatment increases the risk of complications and can lead to the spread of the disease within the community, perpetuating the cycle of infection.⁷

Availability of treatment

The availability of antiparasitic medications is another critical factor influenced by SES. In many LMICs, essential medications for treating parasitic infections are in short supply or are not affordable for the general population. Even when medications are available, the cost can be unaffordable for low-income families, leading to incomplete or inadequate treatment. In some cases, counterfeit or substandard medications may be sold in low-income areas, further complicating treatment efforts.

The availability of preventive measures, such as insecticide-treated bed nets for malaria or mass drug administration (MDA) programmes for helminths, is also limited by SES. In high-income areas, government programmes and healthcare systems are better equipped to distribute these preventive interventions, while in low-income areas, such initiatives may be sporadic or underfunded.⁸

Health-seeking behaviours

SES also shapes health-seeking behaviours, which influence how parasitic infections are managed. Individuals from lower socioeconomic backgrounds may delay seeking care for parasitic infections due to a lack of financial resources, distrust in the healthcare system, or cultural beliefs about illness. In some communities, traditional healers may be the first point of contact for treating parasitic infections, which can delay access to effective biomedical treatment. This is particularly common in areas where healthcare systems are underdeveloped or where there is a long-standing cultural reliance on traditional medicine.

Moreover, individuals from lower socioeconomic backgrounds may be less likely to complete a full course of treatment, either due to financial constraints or a lack of understanding of the importance of adherence. This can lead to the development of drug resistance in parasites, making future infections more difficult and expensive to treat.⁷

Wider determinants of health

The social determinants of health—conditions in which people are born, grow, live, work, and age—also play a significant role in the management of parasitic infections. Those with lower SES often face a range of structural barriers that limit their ability to manage these infections effectively. Poor housing, lack of access to healthcare, limited education, and unemployment are all interrelated factors that contribute to the challenge of controlling parasitic infections in low-income populations.

In addition, the lack of government resources and political will in many LMICs to prioritise parasitic disease control further exacerbates the issue. The allocation of funds for healthcare services, including parasitic disease control programmes, is often limited, particularly in countries with high levels of inequality. This lack of investment in public health infrastructure disproportionately affects low-income populations, who are already at higher risk of infection.⁸

Public health implications

Addressing the influence of SES on susceptibility to and management of parasitic infections requires comprehensive strategies that address the root causes of poverty and inequality. Public health interventions must focus on improving water and sanitation and healthcare infrastructure in low-income communities. Cultural sensitive education campaigns aimed at raising awareness about the prevention and treatment of parasitic infections are essential, particularly in areas with low literacy rates.⁷

Global efforts such as the World Health Organisation’s (WHO) Neglected Tropical Diseases (NTD) roadmap and MDA programmes have been proven effective in reducing the burden of parasitic diseases in LMICs. However, these efforts must be scaled up and adapted to the specific socioeconomic contexts of different regions. Governments, non-governmental organisations (NGOs), and international agencies must cooperate to ensure that antiparasitic medications and preventive measures are accessible and affordable to all.⁹

Summary

• Socioeconomic status plays a vital role in both the susceptibility to and the management of parasitic infections
• Low SES is associated with poor living conditions, inadequate sanitation, malnutrition, limited access to healthcare and lower levels of education, all of which increase the risk of parasitic infections
• Addressing these issues requires a multidisciplinary approach that tackles the root causes of poverty and promotes equal access to healthcare for all
• Improving living conditions, healthcare access and education can significantly reduce the global burden of parasitic infections, improving the quality of life for millions of people worldwide