Bacterial, fungal and parasitic co-infections in leprosy: A scoping review

Abstract

In leprosy patients, the most commonly reported non-viral co-infections are Tuberculosis, Leishmaniasis, Chromoblastomycosis and Helminths. The presence of a secondary infection is believed to increase the likelihood of leprosy reactions. The purpose of this review was to describe the clinical and epidemiological characteristics of the most reported bacterial, fungal, and parasitic co-infections in leprosy. Following the PRISMA Extension for Scoping Reviews guidelines, a systematic literature search was conducted by two independent reviewers, resulting in the inclusion of 89 studies. For tuberculosis, a total of 211 cases were identified, with a median age of 36 years and male predominance (82%). Leprosy was the initial infection in 89% of cases, 82% of individuals had multibacillary disease, and 17% developed leprosy reactions. For leishmaniasis, 464 cases were identified, with a median age of 44 years and male predominance (83%). Leprosy was the initial infection in 44% of cases, 76% of individuals presented with multibacillary disease, and 18% developed leprosy reactions. Regarding chromoblastomycosis, we identified 19 cases with a median age of 54 years and male predominance (88%). Leprosy was the primary infection in 66% of cases, 70% of individuals had multibacillary disease, and 35% developed leprosy reactions. Additionally, we found 151 cases of co-infection with leprosy and helminths, with a median age of 43 years and male predominance (68%). Leprosy was the primary infection in 66% of cases, and 76% of individuals presented with multibacillary disease, while the occurrence of leprosy reactions varied from 37% to 81% across studies. We observed a male-dominated pattern of co-infections among working-age individuals with multibacillary leprosy. Unlike prior studies reporting increased leprosy reactions in chronic viral co-infections, our findings did not indicate any increase among bacterial, fungal, or parasitic co-infections. Rather, co-infections with tuberculosis and leishmaniasis appeared to reduce leprosy reactions. Our review summarizes the clinical and epidemiological characteristics of non-viral co-infections in leprosy patients, including tuberculosis, leishmaniasis, chromoblastomycosis, and helminths. By conducting a systematic literature search, my colleagues and I identified 89 studies and found a male-dominated pattern of co-infections among working-age individuals with multibacillary leprosy. Our findings suggest that co-infections with tuberculosis and leishmaniasis may reduce the occurrence of leprosy reactions, which is in contrast to prior studies reporting increased reactions in chronic viral co-infections. Additionally, we observed that the occurrence of leprosy reactions varied from 37% to 81% across studies, depending on the type of helminth co-infection, which is higher than the general population. Overall, our study highlights the importance of understanding the potential impact of co-infections on leprosy patients, as it may affect their disease outcomes and treatment. This information is relevant not only to researchers and healthcare providers but also to the general public, as leprosy is still a significant public health problem in many parts of the world. Our review adds to the growing body of knowledge in the field of infectious diseases and underscores the need for further research on this topic.