Scabies in Low-Income Asian countries, specifically Vietnam; Full review: pathophysiology, prevalence, diagnosis, prevention, environment, and treatment outbreak.
Abstract:
This paper is about scabies, a highly contagious skin condition that is caused by a mite called Sarcoptes scabiei, which greatly affects many in developing countries. This research paper mostly focuses on the impact in Vietnam and their different diagnostic methods (the 2020 IACS Criteria and the Simplified Criteria). It also focuses on the challenges in Vietnam, which allows scabies to spread infection. This includes having a shortage of nurses and doctors, and having high diagnostic costs. Overall, this research tries to approach the problem of the scabies outbreak in developing countries, specifically Vietnam.
Keywords:
Translational medical sciences; Disease detection and diagnosis; Disease prevention; Infectious disease transmission;, Sarcoptes scabiei; Vietnam
Introduction:
Scabies is a very contagious dermatologic condition caused by an infestation by the female mite, Sarcoptes (Leung, 2023). It affects over 300 million people each year throughout the world (Romani, 2015). The greatest burden of disease are East Asia, Southeast Asia, Oceania, tropical Latin America, and South Asia (Karimkhani, 2017). Children and older people in resource-poor areas are at especially high risk, with prevalence in certain areas ranging from 5% to 50% (WHO, 2023). Scabies spreads very easily from person to person through close contact and, for example, hugging and sexual activity (Heukelbach & Feldmeier, 2006). Crowded spaces like prisons, childcare groups, family homes, hospitals or nursing homes particularly facilitate transmission (CDC, 2020). In addition, the disease can also be spread by sharing clothing, beddings, and furniture infested with mites (Leung, 2023).
This disease is extremely burdensome when contracted. It presents with relentless itching and irritation (Leung, 2023). The itching and rash are a result of the body’s allergic reaction to the mites, their waste, and their eggs (Heukelbach & Feldmeier, 2006). Interestingly enough the large impact of this disease is caused by a tiny (0.3–0.4 mm) mite (Leung, 2023). Particularly, it takes 10–15 mites to typically cause an impact (CDC, 2020). The mite prefers to burrow in the armpits, knees, buttocks, around fingernails, and between the fingers or soles of the feet of adults and older children (Leung, 2023). While in young children, the scalp, neck, face, and palms are more commonly affected (WHO, 2023). Typical morphological lesions in this area appear as diffusely spread papules; nodules may also develop in specific areas (Leung, 2023). While atypical lesions are those that do not fit in this category. If left untreated, then scabies rash can lead to more serious conditions like skin sores, multiorgan issues like septicemia, heart and kidney disease (Romani, 2015).
With the contagious nature, severe disease profile, and the large prevalence, scabies is particularly bothersome for low-income countries whose health systems may not be equipped to handle outbreaks (Heukelbach & Feldmeier, 2006). One country that has been severely impacted by scabies is Vietnam, as it has an extremely high prevalence. The Vietnamese Ministry of Health announced that 2.9% of 6,915,315 people are infected with scabies. This paper explores the various factors that contribute to the scabies epidemic in Vietnam including limited access to care, diagnostic criteria, treatment costs and healthcare facilities outbreaks. The paper also explores various solutions to each of these factors.
Methods Section:
This research paper was created by reviewing multiple existing research papers that were about scabies challenges in Vietnam. These papers talked about scabies transmission, prevalence, and health challenges. Keywords that were used during the searches were “scabies, “developing countries,” “scabies in Vietnam,” “zoning laws in Asia,” and “2020 IACS Criteria.” The certain sources that were chosen were because of its credibility and correct information that would help this paper. There was a lot of data from Vietnam laws that contributed to this research paper as well.
Section 1: Access to care
The lack of access to care in the Vietnamese healthcare system plays a large role in the spread of infection of scabies (Nguyen, 2023). In Vietnam, according to the most recent estimates, only 67% of community health centers have a physician (Ha, 2020). In addition, the lack of adequate supplies for diagnosis and treatment contributes to patients going untreated (Nguyen, 2023). Inadequate funding from governmental organizations and lack of infrastructure can also contribute to the lack of access to care (World Bank, 2022).
Some temporary solutions to this issue include Doctors Without Borders (MSF, 2024). The Vietnamese government could have a partnership with the international NGOs to bring in training, medical help, and clinics to the country (MSF, 2024). Doctors Without Borders specifically provides temporary clinics, personal medical care, training, and emergency support to the country (MSF, 2024). In order to access this service, the Vietnamese government could request support through the NGO’s office (MSF, 2024).
Although an NGO like Doctors Without Borders can provide temporary solutions, a more permanent solution includes increasing the number of Vietnamese doctors (Nguyen, 2023). The government could provide for students with scholarships to attend medical or nursing school, limiting the cost of attendance and encouraging more students to choose the medical path (Tran, 2021). The Vietnamese Ministry of Health to form scholarships with medical schools (MOH Vietnam, 2022).
Section 2: Diagnostic methods: 2020 IACS Criteria vs. Simplified Criteria
Lack of access to care is one contributing factor to the spread of scabies, while another major contributing factor includes the financial cost of diagnosis (Nguyen, 2023). The two main diagnostic criteria are the 2020 IACS Criteria and Simplified Criteria (Engelman, 2021). The gold standard diagnostic criteria, 2020 IACS, was found to have a moderate sensitivity and good specificity for nonexpert users (Engelman, 2021). Per figure 1., this criteria requires the examining recording of a brief history of itch and contacts and a skin examination (Engelman, 2021). This skin examination requires using a microscope to directly visualize mites in the skin (Engelman, 2021). It also includes considering atypical lesions in the assessment and score (Engelman, 2021). Although this is the most accurate method of diagnosis, the high cost of equipment and thorough assessment makes using the criteria difficult in low-resourced countries (Nguyen, 2023).
As a possible solution to the issue, the International Alliance for the Control of Scabies created a simplified criteria (Engelman, 2021). The simplified criteria was developed to address these barriers by reducing training requirements for examiners and eliminating the need for specialized equipment and ultimately making it more feasible in resource-limited settings (Engelman, 2021). Specifically, the simplified criteria only focuses its physical exam on frequently exposed areas, accounts for typical lesions, and requires a community health worker level of training (Engelman, 2021).
Figure 1. Venn Diagram of 2020 IACS Criteria vs. Simplified Criteria.
This criteria was initially validated through surveys distributed to participants in Fiji, Solomon Islands, and Timor-Leste (Engelman, 2021). Information collected included participants’ age, sex, country, and findings of skin examination and history (Engelman, 2021). Overall, there were 9,632 patients who were tested across the studies. 54.8% were from the Solomon Islands, 35.2% were from Fiji, and 10.0% were from Timor-Leste (Engelman, 2021). The study found similar prevalence levels of scabies between the simplified criteria (15.6%) and 2020 IACS criteria (16.6%) with no significant difference between groups (Engelman, 2021).
In Timor-Leste (school-based survey), using the IACS criteria, there was a higher proportion of males having scabies compared to females (Engelman, 2021). There were no statistical differences between the estimates using the two methods by sex or age groups (Engelman, 2021). There were also more false negatives than false positives in both criteria (Engelman, 2021). It was shown that children were more sensitive in the testing, and the numbers decreased as ages got higher (Engelman, 2021). No risk factors have been established for scabies, and it is not a vector-borne disease (Engelman, 2021). This study does have limitations, so the results may not be generalizable to other settings (Engelman, 2021).
Given that the simplified criteria produces similar results to the IACS criteria and it is easier and more affordable to conduct, it makes it a better option for lower-income countries with significant scabies problems (Engelman, 2021).
Section 3: Treatments
After diagnosis the next step is treatment. The most common treatments for scabies are a combination of topical permethrin and oral ivermectin which have the best results (Chosidow, 2006). To treat this condition, topical agents are to be applied to the scalp, navel, groin, fingers, and anywhere else that is needed (Mounsey, 2010). These treatments are safe for all ages and persons, including in pregnancy (Chosidow, 2006). In addition, scabies is highly contagious and spreads throughout the household, thus any surfaces that are touched can be nidus (Heukelbach & Feldmeier, 2006). It is best to wash all bed sheets, towels, at 50 degrees Celsius to ensure the infection is removed (CDC, 2020). After following these procedures, additional follow-up clinic visits may be necessary to ensure effectiveness of treatment (Mounsey, 2010). These are the best treatments that will be crucial and will work the most with the condition (Chosidow, 2006).
There are certain situations where treatments have failed. Reinfection after interacting with infected individuals and improper application of treatments (Heukelbach & Feldmeier, 2006) can lead to treatment failure. It is important that all members of the affected household are treated and their surroundings are taken care of properly to prevent further transmission (CDC, 2020).
Sections 4 - population level Outbreaks in households
Knowing that living conditions are essential to treatment, it’s important to consider the factors that contribute to population spread. Scabies usually comes from poor living habits, such as sharing clothes and unclean households (Fayemiwo, 2023). It is important for adequate cleaning of bedding, and thus the issues mentioned above help facilitate this transmission (Fayemiwo, 2023). To prevent scabies, managing clean personal hygiene is crucial and mandatory (Fayemiwo, 2023). Creating a routine cleaning schedule can overall help with preventing all diseases in general (Fayemiwo, 2023). Washing hands with soap can prevent bacterial, viral, and parasitic infections (Fayemiwo, 2023). Using soap is very important because that is where all of the mites are and the soap would wash them right off (Fayemiwo, 2023). Avoiding borrowing personal items, for example, clothes and towels can also be a big help for avoiding and preventing scabies (Fayemiwo, 2023).
In addition to poor living conditions, household crowding plays a role in the spread of disease (Nguyen, 2023). The number of people per household depends on multiple factors, but predominantly is influenced through culture and local government laws (Tran, 2022). The laws related to the property and composition of a household are known as zoning laws (Smith, 2021). In Vietnam, zoning laws exist but are not as detailed as those of developed countries, for example, the United States (Tran, 2022). For Vietnam, apartments in urban areas require 323 to 1,076 square feet (sq ft) (Tran, 2022). For the United States, apartments require 600 sq ft to 1,500 sq ft (Smith, 2021). However, single-family homes in the United States have 1,200 sq ft to 2,500 sq ft (Smith, 2021). In Vietnam, the Law on Land rule states that residential space per person in rural areas should not go past 400 square meters (Tran, 2022). Compared to Vietnam, the United States allows about 1 to 5 acres for residential land, which is approximately 4,000 to 20,000 square meters (Smith, 2021).
To help this problem, there are multiple affordable solutions to consider. One approach is reforming building codes to allow single-stair apartment buildings up to six stories, which can reduce construction costs by about 10% and increase design flexibility without compromising fire safety, as seen in cities like Seattle and Portland (Johnson, 2023). Another strategy is reviving Single Room Occupancies (SROs), which offer small, affordable units with shared facilities (Johnson, 2023). Community Land Trusts (CLTs) present a nonprofit model that maintains long-term housing affordability by owning the land. An example of CLTs is the Champlain Housing Trust in Vermont which serves over 3,000 families who typically spend no more than 30% of their income on housing (Community Land Trust Network, 2022). Lastly, modular housing has proven effective, This has shown effect in Los Angeles’ Star Apartments which was built for formerly homeless individuals cutting construction costs by 20% and speeding up project timelines by 25%, making it a practical and efficient solution to overcrowding (Johnson, 2023).
Overcrowding is a large problem in many countries, and zoning laws are created to help control and maintain the population (Tran, 2022). Policies that encourage lower-density housing could allow different housing types and more space for families (Johnson, 2023). There can also be established SROs (single room occupancy) to provide affordable housing for low-income individuals, like in Vietnam (Community Land Trust Network, 2022).
Section 5: Healthcare Facilities, and Hospitals Outbreaks
Other crowded places that scabies can occupy are hospitals. Interestingly enough, scabies is mostly overlooked in hospitals when compared to more common infections like bacterial, fungal, and viral ones (Raffi et al., 2019). This is a serious problem as it can eventually lead to delayed diagnoses and treatments (Raffi et al., 2019). But hospitals can have a high infection rate due to the sheer volume and transmission between healthcare workers and patients (Butler & Suresh, 2019).
In addition, individual patient factors can play a role in acquisition and transmissibility of the disease. Factors like immobilization have a large role (Butler & Suresh, 2019). Patients that are bedridden or with compromised immunity have a higher risk of receiving scabies (Raffi et al., 2019). There are also types of patients who remain in the hospital for an extended period of time, which is called reduced mobility (Butler & Suresh, 2019). Reduced mobility is more common with older and elderly people because their bodies are more tender and fragile, which is also true for their hygiene challenges (Raffi et al., 2019). If a patient's blood has poor circulation, and their skin integrity is not where it should be, then they have a much higher risk in receiving scabies because when the blood circulation is poor, then your body is not able to receive all of the nutrients that it needs (Butler & Suresh, 2019). If healthcare workers are not careful when treating their patients, then they will easily receive scabies because of the prolonged skin-to-skin contact with their patient (Raffi et al., 2019). People with a compromised immune system have a higher risk of receiving scabies because their bodies are not strong enough to fight off diseases compared to people with healthy immune systems (Butler & Suresh, 2019). Also, patients that can walk around and are more mobile have less chance of getting scabies compared to patients that are in bed, who are at greater risk (Raffi et al., 2019).
People have a higher chance of receiving scabies in healthcare settings because that is where most of the infested patients are, which leads to bigger outbreaks and a risk for concomitant infections (Raffi et al., 2019). If one does not take action when they receive the disease scabies, then it can lead to future problems that would highly affect one's health even more. The rash would get worse, there would be a worse infection, it could spread to others, and it can take longer to heal if you don't take action right away (Butler & Suresh, 2019). If a patient's body has nutritional deficiencies, then they would have to take extra precautions because their body does not produce enough minerals and vitamins that it needs to stay healthy (Raffi et al., 2019).
Personal factors include conditions related to the living environment, like having poor hygiene. This is common in low-income countries because countries like Vietnam have limited access to clean water and sanitation facilities (Nguyen, 2023). Also, along with patients in hospitals, hospital environments are very important and contribute to scabies transmission (Butler & Suresh, 2019).
Screening for scabies should be prioritized in high-risk settings such as nursing homes and military barracks, where early identification and preventive education can help reduce outbreaks, particularly among healthcare workers who interact frequently with patients (Raffi et al., 2019). Educating patients about personal hygiene and the risks associated with sharing items is crucial in curbing the spread of scabies (Fayemiwo, 2023). Hospitals must enforce robust infection control measures, including the use of personal protective equipment (PPE) for healthcare workers interacting with scabies patients, and implement preventive policies like dermatological exams for at-risk patients (Butler & Suresh, 2019). Further research is crucial on nosocomial scabies, especially in high-income countries like North America and Europe, where scabies has been less studied (Raffi et al., 2019).
Conclusion:
Scabies is a very contagious dermatologic condition caused by an infestation by the female mite, Sarcoptes. It affects millions of people worldwide and has the greatest burden of disease in regions such as East Asia, Southeast Asia, Oceania, tropical Latin America, and South Asia. Children and older people in resource-poor areas are especially vulnerable. Scabies spreads easily from person to person through close contact, such as hugging and sexual activity. Crowded environments like prisons, childcare groups, family homes, hospitals, or nursing homes particularly facilitate transmission. The disease can also spread through sharing clothing, bedding, and furniture infested with mites.
Because of its contagious nature, severe symptoms, and high prevalence, scabies poses a particular challenge for low-income countries whose health systems may not be adequately equipped to handle outbreaks. Vietnam is one such country severely impacted by scabies, with a notably high prevalence reported by the Vietnamese Ministry of Health.
This paper explores the factors contributing to the scabies epidemic in Vietnam, including limited access to care, diagnostic challenges, treatment costs, and outbreaks in healthcare facilities. It also examines potential solutions to these challenges, emphasizing the need for improved healthcare access, affordable diagnostics and treatments, and addressing the environmental and social factors that facilitate transmission.
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