Will cases of leprosy reaction increase with COVID-19 infection?

Viral co-infections in leprosy: a scoping review

CONTEXT

The most reported viral co-infections in leprosy are human immunodeficiency virus (HIV), human T-cell lymphotropic virus (HTLV), hepatitis B virus (HBV), hepatitis C virus (HCV), and SARS-CoV-2. In co-infections, the burden of an agent can be increased or decreased by the presence of others. To address this issue, we need to fully understand their prevalence, risk factors, immunology, clinical manifestations, and treatment. The purpose of this scoping review is to describe the clinical and epidemiological characteristics of the most reported viral co-infections in leprosy to inform clinicians and guide future research.

METHODS

The authors conducted a literature search of five databases for articles on each of the aforementioned co-infections published prior to October 2022. Two independent reviewers conducted the selection process and identified 53 papers meeting the study inclusion criteria. The data extraction process and evidence synthesis were conducted by one reviewer and double-checked by a second one, consistent with best practice recommendations for scoping reviews.

RESULTS

For all assessed viruses, most studies reported prevalence rates in leprosy patients higher than the general population. Studies found that HTLV, HBV, and HCV chronic infections were highest in multibacillary leprosy, whereas HIV was mostly found in paucibacillary leprosy, and SARS-Cov-2 affected leprosy subtypes equally. Overall, co-infections were also associated with higher rates of leprosy reactions, except for COVID-19. Forty-six percent of the studies discussed issues related to treatment, which led to favorable outcomes for the most part.

CONCLUSIONS

This review summarizes the existing literature on viral co-infections in leprosy patients, generating valuable insights and recommending areas for future research.

Hansen's disease and COVID-19 co-infection in Brazil

BACKGROUND

The implications of COVID-19 co-infection in patients under treatment for Hansen's disease (HD, leprosy) remain uncertain. We aimed to describe clinical characteristics, treatments, and outcomes in patients with HD and COVID-19 in Brazil.

METHODS

Cross-sectional study recruiting adult HD patients with PCR-confirmed COVID-19 from five HD treatment centers in Brazil between March 1, 2020, and March 31, 2021. At the time of this study, no patient had received COVID-19 vaccine.

RESULTS

Of 1377 patients under treatment for HD, 70 (5.1%) were diagnosed with COVID-19. Of these, 41 (58.6%) had PCR-confirmed COVID-19, comprising 19 men and 22 women, aged 24-67 (median 45) years. HD was multibacillary in 39/41 patients. Eight patients ceased WHO Multi-Drug Therapy for HD, three for lack of drugs, two because of COVID-19, and three for other reasons. Of the 33 who continued treatment, 26 were on the standard regimen and seven an alternative regimen. Seventeen patients were receiving oral prednisone, including nine patients with type 1 reaction, four with type 2 reaction, three with neuritis, and one with rheumatologic disease. Twelve patients were hospitalized for COVID-19, and six patients died, of whom three had hypertension and one also had type 2 diabetes and obesity.

CONCLUSIONS

COVID-19 and Hansen's disease co-infection did not appear to change the clinical picture of either disease in this cross-sectional study. The wider impact of the pandemic on persons affected by HD requires follow-up and monitoring.

A review of nutrition in neuropathic pain of leprosy

Leprosy is a neglected tropical disease (NTD) that continues to burden low- and middle-income countries (LMICs), despite being eliminated as a public health concern by the World Health Organization (WHO) in 2000. The causative agents, Mycobacterium leprae and Mycobacterium lepromatosis, affect nearly 200,000 individuals globally each year, with over 19,000 new cases detected in the Americas in 2020 alone. Canada has experienced an increasing incidence of leprosy, due to rising levels of travel and migration from endemic areas, reaching over 37,000 individuals with leprosy by the end of 2020. Patients experience a spectrum of signs and symptoms including hypopigmented cutaneous macules alongside peripheral neuropathy including peripheral neuropathic pain (PNP) and disabling sensory neuropathies. Despite the development of effective and curative therapeutics via multidrug therapy (MDT), many barriers to treatment adherence and effective immunological control of the pathogen challenge the care of patients with leprosy. Socioeconomic barriers, such as disability-related social stigma and often undiagnosed nutritional deficiencies, have resulted in heightened disease severity. PNP therapeutics are associated with significant side effects and remain ineffective as the majority of individuals will not experience a greater than 30% reduction of symptoms. Nutrient supplementation is known to be instrumental in reducing host oxidative stress, strengthening the immune system and mitigating comorbidities. Likewise, dietary lifestyle interventions known to be physiologically beneficial have recently emerged as powerful tools conferring neuroprotective effects, potentially mitigating PNP severity. However, a significant knowledge gap concerning the effect of adequate nutrition on host immunological control of leprosy and PNP severity exists. Further evaluation of this relationship will provide key insight into the pathogenesis of leprosy, strengthening the current body of literature.

Kynurenines in the Pathogenesis of Peripheral Neuropathy During Leprosy and COVID-19

Inflammatory disorders are associated with the activation of tryptophan (TRYP) catabolism via the kynurenine pathway (KP). Several reports have demonstrated the role of KP in the immunopathophysiology of both leprosy and coronavirus disease 19 (COVID-19). The nervous system can be affected in infections caused by both Mycobacterium leprae and SARS-CoV-2, but the mechanisms involved in the peripheral neural damage induced by these infectious agents are not fully understood. In recent years KP has received greater attention due the importance of kynurenine metabolites in infectious diseases, immune dysfunction and nervous system disorders. In this review, we discuss how modulation of the KP may aid in controlling the damage to peripheral nerves and the effects of KP activation on neural damage during leprosy or COVID-19 individually and we speculate its role during co-infection.

Type 2 leprosy reaction presenting as a monoarthritis post multidrug therapy

Type 2 leprosy reaction, or erythema nodosum leprosum (ENL), involves a complex interaction between the host's immune system and Mycobacterium leprae. It may occur before, during, or after treatment and have a variable clinical presentation involving different body systems, such as skin, osteoarticular, kidneys, and others. Thus, the differential diagnosis, depending on its clinical presentation, can be broad and challenging. The authors report a case of a severe monoarthritis during a type 2 reaction after the multidrug therapy (MDT) was discharged and the investigation of the differential diagnoses.

Updates on Management of Leprosy in the Context of COVID-19 Pandemic: Recommendations by IADVL SIG Leprosy

The Special Interest Group (SIG) on leprosy thought it to be prudent to revisit its previous practice recommendations through this update. During this period, the pandemic course shifted to a 'second wave' riding on the 'delta variant'. While the number of cases increased manifold, so did the research on all aspects of the disease. Introduction of vaccination and data from various drug trials have an impact on current best practices on management of diseases including leprosy. The beneficial results of using steroids in management of COVID-19, gives elbow room regarding its usage in conditions like lepra reactions. On the other hand, the increase in cases of Mucormycosis again underlines applying due caution while recommending immunosuppressants to a patient already suffering from COVID-19. This recommendation update from SIG leprosy reflects current understanding about managing leprosy while the dynamic pandemic continues with its ebbs and flows.

Impact of the coronavirus disease 2019 on the diagnoses of Hansen's disease in Brazil

INTRODUCTION

Coronavirus disease 2019 (COVID-19) has limited the access of patients with Hansen's disease (HD) to care due to changes in routine health services.

METHODS

To ascertain this, we compared the number of HD cases diagnosed before and after the COVID-19 pandemic.

RESULTS

The decrease in HD cases in Brazil reached 18,223 (-48.4%), corresponding to an average reduction of 1,518 cases per month during the COVID-19 pandemic.

CONCLUSION

Therefore, effective measures should be implemented to minimize the damage and the consequent negative health impact of COVID-19 on the care of HD patients.

The influence of leprosy-related clinical and epidemiological variables in the occurrence and severity of COVID-19: A prospective real-world cohort study

BACKGROUND

Protective effects of Bacillus Calmette-Guérin (BCG) vaccination and clofazimine and dapsone treatment against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported. Patients at risk for leprosy represent an interesting model for assessing the effects of these therapies on the occurrence and severity of coronavirus disease 2019 (COVID-19). We assessed the influence of leprosy-related variables in the occurrence and severity of COVID-19.

METHODOLOGY/PRINCIPAL FINDINGS

We performed a 14-month prospective real-world cohort study in which the main risk factor was 2 previous vaccinations with BCG and the main outcome was COVID-19 detection by reverse transcription polymerase chain reaction (RT-PCR). A Cox proportional hazards model was used. Among the 406 included patients, 113 were diagnosed with leprosy. During follow-up, 69 (16.99%) patients contracted COVID-19. Survival analysis showed that leprosy was associated with COVID-19 (p<0.001), but multivariate analysis showed that only COVID-19-positive household contacts (hazard ratio (HR) = 8.04; 95% CI = 4.93-13.11) and diabetes mellitus (HR = 2.06; 95% CI = 1.04-4.06) were significant risk factors for COVID-19.

CONCLUSIONS/SIGNIFICANCE

Leprosy patients are vulnerable to COVID-19 because they have more frequent contact with SARS-CoV-2-infected patients, possibly due to social and economic limitations. Our model showed that the use of corticosteroids, thalidomide, pentoxifylline, clofazimine, or dapsone or BCG vaccination did not affect the occurrence or severity of COVID-19.

An assessment of the reported impact of the COVID-19 pandemic on leprosy services using an online survey of practitioners in leprosy referral centres

Background

The coronavirus disease 2019 (COVID-19) pandemic has led to governments implementing a variety of public health measures to control transmission and has affected health services. Leprosy is a communicable neglected tropical disease caused by Mycobacterium leprae and is an important health problem in low- and middle-income countries. The natural history of leprosy means that affected individuals need long-term follow-up. The measures recommended to reduce transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can create barriers to health services. We evaluated the impact of the COVID-19 epidemic response on leprosy services and disease management.

Methods

We conducted a cross-sectional online survey with healthcare professionals in leprosy referral centres.

Results

Eighty percent of leprosy diagnostic services were reduced. All respondents reported that multidrug therapy (MDT) was available but two reported a reduced stock. Clinicians used alternative strategies such as telephone consultations to maintain contact with patients. However, patients were not able to travel to the referral centres.

Discussion

This study highlights the effects of the initial phase of the SARS-CoV-2 pandemic on leprosy services in a range of leprosy-endemic countries. Many services remained open, providing leprosy diagnosis, MDT and leprosy reaction medications. Centres developed innovative measures to counter the negative impacts of the COVID-19 pandemic.

Enhanced IL-6 and IL-12B Gene Expression After SARS-CoV-2 Infection in Leprosy Patients May Increase the Risk of Neural Damage

Experts have called attention to the possible negative impact of the coronavirus disease 2019 (COVID-19)–related cytokine storm syndrome on the progression of leprosy-related disabilities. We assessed the frequency of reactional states in patients co-infected with Mycobacterium leprae and severe acute respiratory syndrome (SARS) coronavirus (CoV) 2 (SARS-CoV-2). We consecutively included patients during the first peak of the COVID-19 epidemic in Brazil and analyzed the expressions of genes encoding interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12A, IL-12B, and tumor necrosis factor-α in peripheral blood mononuclear cells. We included 64 leprosy patients and 50 controls. Twelve of the leprosy patients and 14 of the controls had been diagnosed with COVID-19. Co-infection was associated with increased IL-6 (P = 0.043) and IL-12B (P = 0.017) expression. The median disability grades were higher for leprosy/COVID-19 patients; however, the difference was not significant (P = 0.194). Patients co-infected with M. leprae and SARS-CoV-2 may experience a higher-grade proinflammatory state.

Hansen's disease in the era of COVID-19: An observation on a series of six patients with co-infection

Since the onset of the present pandemic, effect of the novel corona virus on other infectious conditions continues to be investigated. Although the immunological responses to SARS‐Cov‐2 infection have been elaborated extensively, they fail to explain, variations in its clinical manifestations and its interaction with other diseases. Hansen's disease is known to present as a complex immunological response to the lepra bacilli, resulting in its varied spectral manifestations. An interaction between these two infectious agents, hence, may affect Hansen's disease. We came across six cases of Hansen's disease who developed COVID19 co‐infection. This series presents their clinical course and outcome, during the period of co‐infection. All cases were followed up for a minimum eight‐week period thereafter. In all these cases the active phase of coronavirus infection had no effect on Hansen's disease and those on prednisolone for their lepra reaction had a more favorable outcome, with two cases manifesting exacerbation of their lepra reactions in the follow period.

COVID-19, leprosy, and neutrophils

Coronavirus Disease 2019 (COVID-19), a disease caused by the betacoronavirus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has only recently emerged, while Mycobacterium leprae, the etiological agent of leprosy, has endured for more than 2,000 years. As soon as the initial reports of COVID-19 became public, several entities, including the Brazilian Leprosy Society, warned about the possible impact of COVID-19 on leprosy patients. It has been verified that COVID-19 carriers can be either asymptomatic or present varying degrees of severe respiratory failure in association with cytokine storm and death, among other diseases. Severe COVID-19 patients show increased numbers of neutrophils and serum neutrophil extracellular trap (NET) markers, in addition to alterations in the neutrophil-to-lymphocyte ratio (NLR). The absence of antiviral drugs and the speed of COVID-19 transmission have had a major impact on public health systems worldwide, leading to the almost total collapse of many national and local healthcare services. Leprosy, an infectious neurological and dermatological illness, is widely considered to be the most frequent cause of physical disabilities globally. The chronic clinical course of the disease may be interrupted by acute inflammatory episodes, named leprosy reactions. These serious immunological complications, characterized by cytokine storms, are responsible for amplifying peripheral nerve damage. From 30% to 40% of all multibacillary leprosy (MB) patients experience erythema nodosum leprosum (ENL), a neutrophilic immune-mediated condition. ENL patients often present these same COVID-19-like symptoms, including high levels of serum NET markers, altered NLR, and neutrophilia. Moreover, the consequences of a M. leprae-SARS-CoV-2 coinfection have yet to be fully investigated. The goal of the present viewpoint is to describe some of the similarities that may be found between COVID-19 and leprosy disease in the context of neutrophilic biology.