Background

Inmates of prisons have significant healthcare needs. Needs range from communicable diseases to mental health and dental care [1–3]. The communicable diseases challenging the health of prisoners include pneumonia, tuberculosis, diarrhoea, hepatitis and skin conditions such as scabies [4–7].

Scabies is a highly contagious parasitic infestation of the skin caused by the mite Sarcoptes scabiei var. hominis and is characterized by intense pruritus, redness, and rash. Scabies is a global health problem, affecting millions of people every year, and it is particularly prevalent in resource-limited settings, including prisons [8, 9]. The overcrowded conditions within prisons can facilitate scabies transmission. Close contact between inmates during activities such as sleeping, sharing bedding or clothing, and participating in recreational activities can facilitate the spread of scabies mites through direct contact. Additionally, factors such as inadequate access to clean water and soap and limited laundry facilities can further exacerbate the spread of scabies in prisons. The capacity of health services in low middle income countries to detect and treat cases of scabies is also limited largely as a result of low awareness and under-diagnosis [8, 10]. Even when cases are identified, there are delays in treatment due in part to non-availability of drugs or high cost of treatment especially for persons without health insurance [11]. In the prison setting, a failure to adequately screen and manage scabies in incoming prisoners, as well as inadequate training of staff on scabies prevention and control practices and a lack of effective scabies control programme, can exacerbate the problem. Studies have shown that the prevalence of scabies vary widely, ranging from 2% to 70%, depending on the location/ region, living conditions, and characteristics of the population studied [9, 12–14]. For example, a study conducted in a prison in Poland found a scabies prevalence rate of 2.3% among inmates [12]. In Tanzania, a much higher prevalence of 69.5% has been reported [13].

The risk of scabies outbreaks is increased in prisoners due to various factors, such as limited access to healthcare, inadequate treatment of cases, lack of awareness among prisoners and staff. Furthermore, delayed diagnosis and treatment of scabies, promotes the spread of the infection among inmates and staff resulting in increased morbidity (especially in cases with secondary infections), mental health distress and increased healthcare costs [15, 16].

Scabies infestation can also cause secondary skin infections, such as impetigo and cellulitis due to scratching and skin breakdown, which can be exacerbated in a prison setting where hygiene practices may be compromised.

Following the categorisation of scabies as a Neglected Tropical Disease (NTD), measures to effectively control the scourge of the disease have been proposed. Mass Drug Administration (MDA) with ivermectin has emerged as one such promising tool for scabies control in endemic settings [15, 16]. MDA with ivermectin leads to a substantial decrease in prevalence of scabies with an additional benefit of about 90% relative reduction in the prevalence of impetigo [15].

Several studies have reported on scabies in community and school [17, 18] and hospital [19, 20] settings in Ghana. However, there is a dearth of information concerning the epidemiology of human scabies in Ghanaian prisons. Therefore, we aimed to assess the burden of scabies and ascertain if its prevalence was alarmingly high enough to warrant MDA with ivermectin in the prison.

Methods

Results

Overall, 559 participants were recruited. Nineteen of the 20 female prisoners consented to participate and no male prisoners refused participation. Most participants were male (540/559 or 96.6%), and the median age was 36.0 (IQR 33–40) years.

Three hundred and sixty-eight (368) of the 559 (65.8%) participants were found to have clinical scabies as assessed by the IACS criteria (Table 1). Scabies severity was mild in 63.3% and moderate in 30.7% of affected individuals. Scabies lesions were most common on the hands, wrists, fingers and finger webs. None of the affected individuals had crusted scabies. Seventy-two (72/559 or 12.9%) had impetigo which was mostly very mild (45.9%) or mild (44.4%) in severity (Table 2).

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Table 1. Characteristics of participants with and without scabies.

https://doi.org/10.1371/journal.pone.0312108.t001

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Table 2. Scabies and impetigo severity in participants with or without clinical scabies.

https://doi.org/10.1371/journal.pone.0312108.t002

No female inmate had clinical scabies. Ninety one percent (507/559) of participants reported that scabies was a common problem in the prison. None of the female prisoners perceived scabies as a problem in their prison.

Contact history was positive in 100% of participants with scabies. Fifty seven percent (57%) had burrows and 98.9% of participants with clinical scabies had rash typical for scabies (Table 1). All participants with scabies reported itch (with a median (IQR) duration of 30 (14–60) days. Only 6% of participants reported no scabies contact in the past weeks. Further, (490/540) 90.7% of male participants reported sharing a bed or bed linen with other cell mates; no female participant shared a bed or linen.

The median (IQR) number of people per cell in the prison was 112 (55–118) as reported by the participants. Among males the median was 115 (56–118) and 7 (7–8) for female prisoners. The median duration of stay in the prison was 7 (3–18) months. Prisoners tended to spend a median of 14 (14–15) hours in their cell.

At the time of assessment, 96 (20.7%) of the participants with scabies had recently received treatment in the past two months because of their skin problems. Ten of these reported receiving topical Benzyl benzoate while 48 received oral ivermectin, 1 received topical permethrin and 37 were treated with other medications such as sulphur and Whitfield’s ointment. Seventy-six (79.2%) of the 96 individuals previously treated still demonstrated skin manifestations which led to an IACS scabies diagnosis. Twenty of the inmates previously treated were free of scabies at the time of skin assessment. In participants without scabies, itch (71.7%) and rash (50.8% were common but these were less than in those with scabies (100% and 98.9% respectively) as shown in Table 1. Seventeen percent of participants with scabies had impetigo compared to 5.8% in individuals without scabies [RR 2.9 (95% CI 1.6–5.5)].

Discussion

Scabies is an infectious parasitic disease that has the potential to spread rapidly in confinement conditions as exists in prisons. In this study in a Ghanaian prison, 65.8% of inmates who were examined had clinical scabies which was mainly mild to moderate in severity. All affected individuals were male with median age of 36 years. Further, impetigo was common among individuals with scabies (17%) than in those without scabies (5.8%). We also identified fungal dermatosis, ulcers, abscess and Kaposi sarcoma in the prison population.

The higher prevalence of scabies in this confinement institution may be as a result of the overcrowding of the prison leading to a large number of prisoners per cell. Furthermore, close contact between prisoners during sleep times may promote spread of scabies.

In Cameroon, a scabies prevalence of 32% has been reported among prisoners and overcrowding, male gender, sharing of clothing and low educational status, were independent drivers of scabies occurrence in the three prisons studied [9]. Leppard and colleagues [13] found a prevalence of 69.5% in a Tanzanian prison. In another study, a scabies prevalence of 2.3% was found among Polish prisoners [12]. In some countries [12], initial medical examinations are carried out by a general practitioner within a few days after imprisonment, while diagnostic examinations are performed at intervals; such scheduled assessments can lead to early detection and treatment of scabies cases and reduce the potential for outbreaks. The overcrowding and lack of systematic efforts to detect and control scabies in the Ghanaian prison may account for the very high scabies prevalence observed in the current study. It is recommended that the prison institutes a scabies control programme that incorporates health education and scheduled or periodic examination of inmates to promote early detection and appropriate treatment of scabies and other common skin conditions to facilitate control. Additionally, inmates should be encouraged to report their own disease to the prison service, as this can substantially accelerate the implementation of therapy for scabies. Efforts should be made to decongest the prison and improve the general access to healthcare in the prison. Health education for inmates and staff can also help reduce stigmatization of affected individuals in such settings.

Mental disorders like depression and anxiety are prevalent among Ghanian prisoners [26]. Intense pruritus from scabies can further threaten mental health and may lead to increased tension between inmates.

In our study, 17% of participants had received treatment for their skin problems in the t 2 months preceding the assessment. However, 79.2% of the individuals who were previously treated still exhibited skin manifestations of scabies; these may include individuals with post scabies itch, reinfections/ recurrences or non-response to treatment/ treatment failure. There had been no treatment of the contacts of previously identified scabies cases. The lack of a systematic approach to the treatment of previously identified scabies cases and their contacts likely led to reinfection of individuals and ongoing spread within the prison. Additionally, the overcrowded living conditions, limited access to healthcare and inadequate Water, Sanitation and Hygiene (WASH) facilities may have facilitated scabies spread within the prison. There is the need to explore strategies for more effective control of scabies within this prison setting. A high percentage of individuals without scabies had an itch or rash but did not meet the IACS criteria for clinical scabies. It is possible that the IACS criteria does not work as well in such high-risk settings. These may also include persons with alternative diagnosis such as fungal dermatosis, eczema, pediculosis or other infestations.

There are different strategies for scabies control. A control strategy of treating clinically affected persons and their contacts may provide temporary relief for the individuals but has limited success in reducing population prevalence in the longer term [27].

Mass drug administration (MDA) using topical permethrin or oral ivermectin offers an alternative approach for population control to substantially reduce the burden of scabies.

Mass treatment of highly endemic communities with topical 5% permethrin has been reported to substantially reduce scabies prevalence [28–31]. In another study with permethrin, although the scabies prevalence remained unchanged, the prevalence of secondary infected scabies decreased from 3.7% to 1.5% indicating a relative reduction of 59% [32].

Topical permethrin is expensive and requires application to the whole body. Other disadvantages of topical agents include inadequate application to local lesions, a lack of privacy to undertake whole-body application, insufficient facilities to rinse off the cream, poor compliance among contacts of scabies cases and discomfort due to topical treatment [33]. These factors constitute major barriers for effective use of topical therapy for population control of scabies, especially in the prison setting.

Ivermectin, as an oral therapy can offset some of the challenges associated with topical treatment and can potentially increase compliance resulting in better control of scabies in affected populations [8, 34]. Studies on MDA with ivermectin performed in island settings [15, 16, 35] reported a reduced prevalence of scabies. Compared to topical permethrin, oral ivermectin resulted in larger reductions in scabies prevalence at 12 and 24 months [15]. Recently, mass screening and community treatment (MSAT) of cases and their contacts with oral ivermectin delivered by community health workers has been shown to be superior to mass screening followed by usual care involving referral to clinic for topical treatment in controlling scabies in India [34]. While MSAT with ivermectin showed promising results and has relatively lower costs, the approach might miss persons with subclinical scabies making it less effective than MDA [34]. Furthermore, MSAT does not target people who work in the prison and may be contacts of scabies cases.

We found a scabies prevalence in the prison which is much higher than the 10% threshold set for MDA [36]. In the current study, individuals with scabies were treated with topical benzyl benzoate as recommended in Ghana. However, the high prevalence and large number of contacts (entire prison population including staff and health workers) make MDA with ivermectin imperative. An urgent collaborative effort involving multiple stakeholders such as the Ghana Prisons Service, the Ghana Health Service, civil society and non-governmental organisations and donors is needed to mobilise adequate doses of ivermectin to undertake an MDA in this institutionalized setting.

Ivermectin is contraindicated in children < 5 years old, persons with severe concurrent illness, individuals with hypersensitivity to components of the drug, and pregnancy. Inadequate community engagement, lack of political support and high costs are potential barriers that may pose challenges for MDA implementation [37, 38]. Furthermore, due to its lack of ovicidal action, a second dose of ivermectin is usually recommended after 7–14 days for individual treatment, to kill newly hatched mites. Administration of a second dose that is separated by several days as MDA is logistically challenging and is associated with higher costs. An oral agent with a longer duration of activity in the skin, that could persist for sufficient time to kill newly hatched mites, would make the requirement for a second dose unnecessary. Moxidectin with a half-life of up to 43 days, and prolonged activity in the skin offers promise in this regard [39]. An initial preclinical study reported that oral single dose moxidectin was more effective than two consecutive doses of ivermectin for treating scabies [40]. In future moxidectin may be even more helpful as its longer half-life may render it more efficient in the prison setting where interactions between people are not restricted by geographic boundaries as exists in island populations.

Conclusion

There is a very high prevalence of scabies and impetigo in this medium security Ghanaian prison. Monitoring the health of prisoners can facilitate early response to emerging cases of scabies and help limit the potential for outbreaks in prisons. To minimise the problem, urgent measures including health education and MDA with ivermectin are needed to address this major public health issue in the prison.

Acknowledgments

We would like to thank the administration and staff of the Kumasi Central prisons. We appreciate all the inmates of the prison for their practical involvement in this study. A special thanks goes to Mr Collins Asare and staff of the skin NTDs Research group at the Kumasi Centre for Collaborative Research for providing administrative support.