The diagnosis of American Tegumentary Leishmaniasis is a difficult but essential task
when considering the high toxicity profile of the drugs available. Since the
discovery of its etiologic agent, numerous diagnostic tests have been developed. None
of the tests available today can be considered as the gold standard, since they do
not add enough accuracy for the disease detection. Good epidemiological and clinical
knowledge of the disease are fundamental precepts of the dermatology practice and
precede the rational use of existing diagnostic tests. In this article we aim,
through extensive literature review, to recall fundamental concepts of any diagnostic
test. Subsequently, based on this information, we will weave important comments about
the characteristics of existing diagnostic tests, including immunological tests such
as Montenegro's skin test, serology and detection of parasites by direct examination,
culture or histopathology. Finally we will discuss the new technologies and options
for the diagnosis of Cutaneous Leishmaniasis. The molecular biology technique is
considered a promising tool, promoting the rapid identification of the species
involved. We also aim to educate dermatologists about a disease with high morbidity
and assist in its difficult recognition.
The precise diagnosis of American tegumentary leishmaniasis (ATL) is an essential task due to the disease's associated morbidity. A noninvasive, extremely sensitive, and highly specific exam is critical, particularly for mucosal leishmaniasis (ML), in which a low parasite quantity is expected. We aimed to compare the diagnostic accuracy of swab and biopsy sample analysis using SYBR Green-and TaqManbased real-time PCR (qPCR) assays with that of a composite reference standard consisting of the Montenegro skin test, serology, histopathology, smears, culture, and conventional PCR. In total, 55 patients with ATL (ML, 18 patients; cutaneous leishmaniasis [CL], 37 patients) and 36 patients without ATL were studied. qPCR analysis of swabs was more accurate when using SYBR Green (87.88%; 95% confidence interval [CI], 77.86 to 93.73 patients) than when using TaqMan (78.79%; 95% CI, 67.49 to 86.92%) (P ϭ 0.031). SYBR Green (84.72%; 95% CI, 74.68 to 91.25%) was also more accurate than TaqMan (73.61%; 95% CI, 62.42 to 82.41%) for biopsy samples (P ϭ 0.008). All qPCR methods were 100% specific. Swabs and biopsy specimens had similar sensitivity when using the same chemistry (P ϭ 0.125 for SYBR Green and P ϭ 0.625 for TaqMan). Moreover, qPCR achieved better performance than most existing techniques used for the diagnosis of ATL and also detected the Leishmania parasite in a greater proportion of patients than the associated histopathology, smear, culture, and conventional PCR techniques did. Swabs therefore represent a useful diagnostic tool because they not only are noninvasive but also can achieve an accuracy similar to that of biopsy samples. The high accuracy of SYBR Green-based qPCR may also reduce the requirement for associated parasitological tests for ATL diagnosis.
OBJECTIVESShow that hidden endemic leprosy exists in a municipality of inner São Paulo
state (Brazil) with active surveillance actions based on clinical and
immunological evaluations.METHODSThe study sample was composed by people randomly selected by a dermatologist
during medical care in the public emergency department and by active
surveillance carried out during two days at a mobile clinic. All subjects
received a dermato-neurological examination and blood sampling to determine
anti-PGL-I antibody titers by enzyme-linked immunosorbent assay (ELISA).RESULTSFrom July to December 2015, 24 new cases of leprosy were diagnosed; all were
classified as multibacillary (MB) leprosy, one with severe Lucio's
phenomenon. Seventeen (75%) were found with grade-1 or 2 disability at the
moment of diagnosis. Anti-PGL-I titer was positive in 31/133 (23.3%)
individuals, only 6/24 (25%) were positive in newly diagnosed leprosy
cases.CONCLUSIONSDuring the last ten years before this study, the average new case detection
rate (NCDR) in this town was 2.62/100,000 population. After our work, the
NCDR was raised to 42.8/100,000. These results indicate a very high number
of hidden leprosy cases in this supposedly low endemic area of Brazil.
Background
This study evaluates an active search strategy for leprosy diagnosis based on responses to a Leprosy Suspicion Questionnaire (LSQ), and analyzing the clinical, immunoepidemiological and follow-up aspects for individuals living in a prison population.
Methods
A cross-sectional study based on a questionnaire posing 14 questions about leprosy symptoms and signs that was distributed to 1,400 prisoners. This was followed by dermatoneurological examination, anti-PGL-I serology and RLEP-PCR. Those without leprosy were placed in the Non-leprosy Group (NLG, n = 1,216) and those diagnosed with clinical symptoms of leprosy were placed in the Leprosy Group (LG, n = 34).
Findings
In total, 896 LSQ were returned (64%), and 187 (20.9%) of the responses were deemed as positive for signs/symptoms, answering 2.7 questions on average. Clinically, 1,250 (89.3%) of the prisoners were evaluated resulting in the diagnosis of 34 new cases (LG), based on well-accepted clinical signs and symptoms, a new case detection rate of 2.7% within this population, while the NLG were comprised of 1,216 individuals. The confinement time medians were 39 months in the LG while it was 36 months in the NLG (p>0.05). The 31 leprosy cases who responded to the questionnaire (LSQ+) had an average of 1.5 responses. The symptoms “anesthetized skin area” and “pain in nerves” were most commonly mentioned in the LG while “tingling, numbness in the hands/feet”, “sensation of pricks and needles”, “pain in nerves” and “spots on the skin” responses were found in more than 30% of questionnaires in the NLG. Clinically, 88.2% had dysesthetic macular skin lesions and 97.1% presented some peripheral nerve impairment, 71.9% with some degree of disability. All cases were multibacillary, confirming a late diagnosis. Anti-PGL-I results in the LG were higher than in the NLG (p<0.0001), while the RLEP-PCR was positive in 11.8% of the patients.
Interpretation
Our findings within the penitentiary demonstrated a hidden prevalence of leprosy, although the individuals diagnosed were likely infected while living in their former communities and not as a result of exposure in the prison. The LSQ proved to be an important screening tool to help identify leprosy cases in prisons.
An epidemiological link between biting flies and PF in southeastern Brazil is proposed, implying a possible role of the salivary proteins from these flies in PF etiopathogenesis.
We conclude that superficial sampling can retrieve a greater quantity of parasites. Future studies of the role of transepidermal elimination as a mechanism of host defence in ATL must be performed as there is a considerable quantity of Leishmania kDNA in the epidermis.
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.
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