Active search strategies, clinicoimmunobiological determinants and training for implementation research confirm hidden endemic leprosy in inner São Paulo, Brazil

Abstract

Background This study evaluates implementation strategies for leprosy diagnosis based on responses to a Leprosy Suspicion Questionnaire (LSQ), and analyzes immunoepidemiological aspects and follow-up of individuals living in a presumptively nonendemic area in Brazil. Methodology/Principal findings Quasi-experimental study based on LSQ throughout Jardinópolis town by community health agents, theoretical-practical trainings for primary care teams, dermatoneurological examination, anti-PGL-I serology, RLEP-PCR, and spatial epidemiology. A Leprosy Group (LG, n = 64) and Non-Leprosy Group (NLG, n = 415) were established. Overall, 3,241 LSQs were distributed; 1,054 (32.5%) LSQ were positive for signs/symptoms (LSQ+). Among LSQ+ respondents, Q2-Tingling (pricking)? (11.8%); Q4-Spots on the skin? (11.7%); Q7-Pain in the nerves? (11.6%); Q1-Numbness in your hands and/or feet? (10.7%) and Q8-Swelling of hands and feet? (8.5%) were most frequently reported symptoms. We evaluated 479 (14.8%) individuals and diagnosed 64 new cases, a general new case detection rate (NCDR) of 13.4%; 60 were among 300 LSQ+ (NCDR-20%), while 4 were among 179 LSQ negative (NCDR-2.23%). In LG, Q7(65%), Q2(60%), Q1(45%), Q4(40%) and Q8(25%) were most frequent. All 2x2 crossings of these 5 questions showed a relative risk for leprosy ranging from 3 to 5.8 compared with NLG. All patients were multibacillary and presented hypochromatic macules with loss of sensation. LG anti-PGL-I titers were higher than NLG, while 8.9% were positive for RLEP-PCR. The leprosy cases and anti-PGL-I spatial mappings demonstrated the disease spread across the town. Conclusions/Significance Implementation actions, primarily LSQ administration focused on neurological symptoms, indicate hidden endemic leprosy in a nonendemic Brazilian state.

Leprosy case series in the emergency room: A warning sign for a challenging diagnosis

“…The decline in leprosy prevalence and the commitment to leprosy elimination as a public health problem in many countries have been accompanied by a decline in disease expertise. 9 Leprosy can mimic many common dermatological and neurological conditions, 4 , 5 leading to delays in diagnosis. However, even in the presence of anesthetic lesions with thickened nerves, hallmarks signs, many physicians seem to lack the skills to diagnose leprosy, even the classic forms.…”

“…Diagnosis of leprosy, essentially clinical, is based upon detection of at least one of the following signs/symptoms: a) lesion(s) and/or area(s) of the skin with changes in thermal and/or pain and/or tactile sensitivity; b) thickening of peripheral nerve(s), associated with sensory and/or motor and/or autonomic changes; and/or c) presence of M. leprae , confirmed by smear microscopy or skin biopsy, 3 that can be confirmed by RLEP-PCR. 4 , 5 …”

“…Considering that neural involvement is present in all clinical forms of leprosy, as damage to the nerve trunks and/or cutaneous nerve endings, 5 , 7 the evaluation of these nerves by ultrasound is helpful due to the possibility of examining a larger territory of the nerve that may be inaccessible to clinical examination, as well as better locating and defining the thickening point and/or peripheral nerve alteration. 8 …”

Serological Immunoassay for Hansen’s Disease Diagnosis and Monitoring Treatment: Anti-Mce1A Antibody Response Among Hansen’s Disease Patients and Their Household Contacts in Northeastern Brazil

“…There is no laboratory test capable of detecting all clinical forms of HD. The knowledge and skills required for an HD diagnosis, treatment and management by general health workers are unsatisfactory, leading to delayed diagnosis, physical disabilities, socioeconomic impairment, and continued M. leprae transmission ( 9 ). Bacilloscopy from slit skin smears is the standard laboratory test to detect M. leprae , although highly specific, has a low sensitivity and it is performed only in presumed HD cases, and is negative in the majority of initial or neural forms.…”

Bacilloscopy and polymerase chain reaction of slit-skin smears and anti-phenolic glycolipid-I serology for Hansen’s disease diagnosis

“…Although the guidelines also reported polymerase chain reaction (PCR)-based assays as being associated with higher diagnostic accuracy, they lack standardization, are not commercially available, and would be difficult to perform in most primary health-care settings ( 3 ). Thus, the need to intensify the development and improvement of current laboratory methodologies for the early and satisfactory diagnosis of the disease is evident ( 4 , 5 ). However, different clinical, bacteriological, and immunopathological characteristics constitute the spectrum of the disease and express the relationship between the pathogenicity of the bacilli and the host’s immune response, which makes it difficult and unfeasible to control the disease ( 6 ).…”