Live, Attenuated, Tetravalent Butantan-Dengue Vaccine in Children and Adults.

BACKGROUND: Butantan-Dengue Vaccine (Butantan-DV) is an investigational, single-dose, live, attenuated, tetravalent vaccine against dengue disease, but data on its overall efficacy are needed. METHODS: In an ongoing phase 3, double-blind trial in Brazil, we randomly assigned participants to receive Butantan-DV or placebo, with stratification according to age (2 to 6 years, 7 to 17 years, and 18 to 59 years); 5 years of follow-up is planned. The objectives of the trial were to evaluate overall vaccine efficacy against symptomatic, virologically confirmed dengue of any serotype occurring more than 28 days after vaccination (the primary efficacy end point), regardless of serostatus at baseline, and to describe safety up to day 21 (the primary safety end point). Here, vaccine efficacy was assessed on the basis of 2 years of follow-up for each participant, and safety as solicited vaccine-related adverse events reported up to day 21 after injection. Key secondary objectives were to assess vaccine efficacy among participants according to dengue serostatus at baseline and according to the dengue viral serotype; efficacy according to age was also assessed. RESULTS: Over a 3-year enrollment period, 16,235 participants received either Butantan-DV (10,259 participants) or placebo (5976 participants). The overall 2-year vaccine efficacy was 79.6% (95% confidence interval [CI], 70.0 to 86.3) - 73.6% (95% CI, 57.6 to 83.7) among participants with no evidence of previous dengue exposure and 89.2% (95% CI, 77.6 to 95.6) among those with a history of exposure. Vaccine efficacy was 80.1% (95% CI, 66.0 to 88.4) among participants 2 to 6 years of age, 77.8% (95% CI, 55.6 to 89.6) among those 7 to 17 years of age, and 90.0% (95% CI, 68.2 to 97.5) among those 18 to 59 years of age. Efficacy against DENV-1 was 89.5% (95% CI, 78.7 to 95.0) and against DENV-2 was 69.6% (95% CI, 50.8 to 81.5). DENV-3 and DENV-4 were not detected during the follow-up period. Solicited systemic vaccine- or placebo-related adverse events within 21 days after injection were more common with Butantan-DV than with placebo (58.3% of participants, vs. 45.6%). CONCLUSIONS: A single dose of Butantan-DV prevented symptomatic DENV-1 and DENV-2, regardless of dengue serostatus at baseline, through 2 years of follow-up. (Funded by Instituto Butantan and others; DEN-03-IB ClinicalTrials.gov number, NCT02406729, and WHO ICTRP number, U1111-1168-8679.).

The role of pets in SARS-CoV-2 transmission: an exploratory analysis.

PURPOSE: There is evidence that humans can transmit SARS-CoV-2 to cats and dogs. However, there is no evidence that they can transmit it back to humans or play any role in SARS-CoV-2 transmission. Here, we present an exploratory analysis on that matter. METHODS: We conducted a case-control study with participants with flu-like symptoms seeking care at a primary healthcare unit to be tested for COVID-19. They were asked if they owned pet cats and/or dogs in their residences, and this variable was evaluated as exposure. RESULTS: The odds ratio of "having dogs and/or cats in the residence" was 1.29 (95% CI 1.08-1.54) of "having only dogs and no cats" was 1.26 (1.05-1.52), and "no dogs and only cats" was 1.29 (0.95-1.75). CONCLUSION: Having a cat/dog in the house can affect the risk of infection by SARS-CoV-2.

Methylprednisolone as Adjunctive Therapy for Patients Hospitalized With Coronavirus Disease 2019 (COVID-19; Metcovid): A Randomized, Double-blind, Phase IIb, Placebo-controlled Trial.

BACKGROUND: Steroid use for coronavirus disease 2019 (COVID-19) is based on the possible role of these drugs in mitigating the inflammatory response, mainly in the lungs, triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to evaluate the efficacy of methylprednisolone (MP) among hospitalized patients with suspected COVID-19. METHODS: A parallel, double-blind, placebo-controlled, randomized, Phase IIb clinical trial was performed with hospitalized patients aged ≥18 years with clinical, epidemiological, and/or radiological suspected COVID-19 at a tertiary care facility in Manaus, Brazil. Patients were randomly allocated (1:1 ratio) to receive either intravenous MP (0.5 mg/kg) or placebo (saline solution) twice daily for 5 days. A modified intention-to-treat (mITT) analysis was conducted. The primary outcome was 28-day mortality. RESULTS: From 18 April to 16 June 2020, 647 patients were screened, 416 were randomized, and 393 were analyzed as mITT, with 194 individuals assigned to MP and 199 to placebo. SARS-CoV-2 infection was confirmed by reverse transcriptase polymerase chain reaction in 81.3%. The mortality rates at Day 28 were not different between groups. A subgroup analysis showed that patients over 60 years old in the MP group had a lower mortality rate at Day 28. Patients in the MP arm tended to need more insulin therapy, and no difference was seen in virus clearance in respiratory secretion until Day 7. CONCLUSIONS: The findings of this study suggest that a short course of MP in hospitalized patients with COVID-19 did not reduce mortality in the overall population. CLINICAL TRIALS REGISTRATION: NCT04343729.

Accuracy of diagnostic tests for American tegumentary leishmaniasis: a systematic literature review with meta-analyses.

OBJECTIVES: To analyse the accuracy of American tegumentary leishmaniasis (ATL) diagnostic methods and evaluate the quality of the existing publications by means of a systematic review. METHODS: Diagnostic tests evaluated in at least two studies with common reference standards were included in the sensitivity and/or specificity meta-analyses. Quality and susceptibility to bias were analysed using the QUADAS-2 and STARD tools. RESULTS: The title and abstract of 3387 publications were evaluated after deduplication resulting from database searches. Thirty-eight studies were included in the review, and 26 of them had results inserted in meta-analyses. The diagnostic methods with the highest pooled sensitivity values were ELISA, polymerase chain reaction (PCR), indirect immunofluorescence reaction and Montenegro's intradermal reaction. Cytometry was assessed in only two studies and presented 100% sensitivity in both. Smear slide microscopy and histopathology showed low pooled values of sensitivity. For specificity, the highest pooled values were identified for PCR. High values were also identified for ELISA, except for studies in which the reference standard for defining negative participants included individuals with Chagas' disease or paracoccidioidomycosis, which also occurred for cytometry. IFR had lower specificities than ELISA. There was a predominance of case-control designs of phase 1 or 2 and only four studies were strongly recommended as evidence generators. Several reference standards were adopted, and different methods were assessed in a small number of studies. CONCLUSION: PCR showed the highest accuracy for the diagnosis of ATL, and its use should be encouraged in clinical practice. ELISA is recommended for the screening of suspected individuals, but the possibility of cross-reactions should be considered. New validation studies for the tests evaluated in few publications and studies of phase 3 with appropriate methods are needed.

OBJECTIFS: Analyser l'exactitude des méthodes de diagnostic de la leishmaniose tégumentaire américaine (LTA) et évaluer la qualité des publications existantes au moyen d'une analyse systématique. MÉTHODES: Les tests diagnostiques évalués dans au moins deux études avec des étalons de référence communs ont été inclus dans les méta-analyses de sensibilité et/ou de spécificité. La qualité et la sensibilité au biais ont été analysées à l'aide des outils QUADAS-2 et STARD. RÉSULTATS: Le titre et le résumé de 3387 publications ont été évalués après déduplication résultant de recherches dans la base de données. 38 études ont été incluses dans la revue et 26 d'entre elles ont eu des résultats inclus dans des méta-analyses. Les méthodes de diagnostic avec les valeurs de sensibilité poolées les plus élevées étaient ELISA, la réaction en chaîne par polymérase (PCR), la réaction d'immunofluorescence indirecte et la réaction intradermique du Monténégro. La cytométrie a été évaluée dans seulement deux études et présentait une sensibilité de 100% dans les deux. La microscopie et l'histopathologie sur lame de frottis ont montré de faibles valeurs poolées de sensibilité. Pour la spécificité, les valeurs poolées les plus élevées ont été identifiées pour la PCR. Des valeurs élevées ont également été identifiées pour l'ELISA, à l'exception des études dans lesquelles la norme de référence pour définir les participants négatifs incluait des individus atteints de la maladie de Chagas ou de paracoccidioïdomycose, qui s'est également produite pour la cytométrie. L'IFR avait des spécificités plus faibles que l'ELISA. Il y avait une prédominance des essais cas-témoins de phases 1 ou 2 et seules quatre études étaient fortement recommandées comme génératrices de preuves. Plusieurs normes de référence ont été adoptées et différentes méthodes ont été évaluées dans un petit nombre d'études. CONCLUSION: la PCR a montré la plus grande exactitude pour le diagnostic de l'ATL et son utilisation doit être encouragée dans la pratique clinique. L'ELISA est recommandé pour le dépistage des personnes suspectées, mais la possibilité de réactions croisées doit être considérée. De nouvelles études de validation des tests évalués dans quelques publications et des études de phase 3 avec des méthodes appropriées sont nécessaires.

A cross-sectional approach including dog owner characteristics as predictors of visceral leishmaniasis infection in dogs.

BACKGROUND: Visceral leishmaniasis (VL) is relevant for human and animal public health. Several factors have been associated with the risk of Leishmania infantum infection in dogs. However, dog owner characteristics have been rarely explored. OBJECTIVES: To estimate the prevalence and to identify the associated factors for VL infection including dog owners characteristics. METHODS: A cross-sectional study was conducted including dogs from an endemic canine visceral leishmaniasis (CVL) region in the Federal District, Brazil. The infection was detected using parasitological, serological, and molecular methods. The associated factors were identified through Poisson regression modelling. FINDINGS: The prevalence of infection was 26.25% [95% confidence interval (CI): 20.05 to 33.57]. The associated factors were: short coat prevalence ratio (PR) = 2.33 (95% CI: 1.02 to 5.22); presence of backyard with predominance of soil and/or vegetation PR = 4.15 (95% CI: 1.35 to 12.77); and highest gross family income score PR = 2.03 (95% CI: 1.16 to 3.54). MAIN CONCLUSION: This is the first study that relates higher socioeconomic status of dog owners as an independent factor associated with higher prevalence of VL infection, along with other strongly associated factors related to receptive environment for phlebotomines. Our findings strengthen the need for exploration of the biological and behavioural bases linking dog owner characteristics to the risk of canine infection in prospective cohort studies.

Treatment for human visceral leishmaniasis: a cost-effectiveness analysis for Brazil.

OBJECTIVE: To estimate the cost-effectiveness of strategies for the treatment of VL in Brazil. METHODS: Cost-effectiveness study comparing three therapeutic options: meglumine antimoniate (MA), liposomal amphotericin B (LAMB) and a combination of LAMB plus MA (LAMB plus MA), from public health system and societal perspectives. An analytical decision-making model was used to compare strategies for the following outcomes: early therapeutic failure avoided at 30 days, days of hospitalisation avoided and VL cure at 180 days. The efficacy and safety parameters of the drugs came from a randomised, open-label trial and the cost data came from a cost-of-illness study, both carried out in Brazil. RESULTS: For all outcomes analysed, the LAMB strategy was more effective. The MA strategy was inferior to the LAMB plus MA strategy for the outcomes early therapeutic failure avoided and cure. When only LAMB and MA were compared from a societal perspective, a cost of US$ 278.56 was estimated for each additional early therapeutic failure avoided, a cost of US$ 26.88 for each additional day of hospitalisation avoided and a cost of US$ 89.88 for each additional case of cured VL, for the LAMB strategy vs. MA. CONCLUSION: In Brazil, the LAMB strategy proved to be cost-effective for treating VL, considering a GDP per capita as the willingness-to-pay threshold, for all of the outcomes analysed in comparison to MA.

OBJECTIF: Estimer la rentabilité des stratégies de traitement de la leishmaniose viscérale (LV) au Brésil. MÉTHODES: Etude coût-efficacité comparant trois options thérapeutiques: l'antimoniate de méglumine (AM), amphotéricine B liposomale (LAMB) et une combinaison de LAMB et MA (LAMB plus AM), du point de vue du système de santé publique et sociétal. Un modèle décisionnel analytique a été utilisé pour comparer les stratégies pour les résultats suivants: échec thérapeutique précoce évité à 30 jours, jours d'hospitalisation évités et guérison de la LV à 180 jours. Les paramètres d'efficacité et de sécurité des médicaments provenaient d'un essai randomisé ouvert et les données relatives aux coûts, d'une étude sur le coût de la maladie, toutes deux menées au Brésil. RÉSULTATS: Pour tous les résultats analysés, la stratégie LAMB était plus efficace. La stratégie AM était inférieure à la stratégie LAMB plus AM pour les résultats: échec thérapeutique précoce évité et guérison. Lorsque seules les stratégies LAMB et AM ont été comparées d'un point de vue sociétal, un coût de 278,56 USD a été estimé pour chaque échec thérapeutique précoce additionnel évité, un coût de 26,88 USD pour chaque jour d'hospitalisation additionnel évité et un coût de 89,88 USD pour chaque cas additionnel de LV guéri, pour la stratégie LAMB par rapport à AM. CONCLUSION: Au Brésil, la stratégie LAMB s'est avérée rentable pour traiter la LV, considérant un PIB par habitant comme seuil de volonté de payer, pour tous les résultats analysés par rapport à l'AM.

Improving the reference standard for the diagnosis of canine visceral leishmaniasis: a challenge for current and future tests.

BACKGROUND: Studies aimed at validating canine visceral leishmaniasis diagnostic tests present heterogeneous results regarding test accuracy, partly due to divergences in reference standards used and different infection evolution periods in animals. OBJECTIVE: This study aimed to evaluate the accuracy of the rapid test-dual path platform (TR-DPP) (Biomanguinhos®), EIE-Leishmaniose-Visceral-Canina-Biomanguinhos (EIE-LVC) (Biomanguinhos®), enzyme-linked immunosorbent assay (ELISA) rK39 (in-house), and the direct agglutination test (DAT-Canis) against a reference standard comprising parasitological and molecular techniques. METHODS: A phase II/III validation study was carried out in sample sera from 123 predominantly asymptomatic dogs living in an area endemic for visceral leishmaniasis. FINDINGS: Sixty-nine (56.1%) animals were considered infected according to the reference standard. For each test, the sensitivity and specificity, respectively, were as follows: TR-DPP, 21.74% [confidence interval (CI)95% 13.64% to 32.82%] and 92.59% (CI95% 82.45% to 97.08%); EIE-LVC, 11.59% (CI95% 5.9% to 21.25%) and 90.74% (CI95% 80.09% to 95.98%); ELISA rK39, 37.68% (CI95% 27.18% to 49.48%) and 83.33% (CI95% 71.26% to 90.98%); and DAT-Canis, 18.84% (CI95% 11.35% to 29.61%) and 96.30% (CI95% 87.46% to 98.98%). CONCLUSION: We concluded that improving the sensitivity of serum testing for diagnosing asymptomatic dogs must constitute a priority in the process of developing new diagnostic tests to be used in the visceral leishmaniasis control program in Brazil.

Effectiveness of dog collars impregnated with 4% deltamethrin in controlling visceral leishmaniasis in Lutzomyia longipalpis (Diptera: Psychodidade: Phlebotominae) populations.

BACKGROUND: There is little information on the effect of using deltamethrin-impregnated dog collars for the control of canine visceral leishmaniasis. OBJECTIVES: The objective of this study was to evaluate the effectiveness of the use of 4% deltamethrin-impregnated collars (Scalibor®) in controlling visceral leishmaniasis in Lutzomyia longipalpis by comparing populations in intervention and non-intervention areas. METHODS: Phlebotomine flies were captured over 30 months in four neighbourhoods with intense visceral leishmaniasis transmission in Fortaleza and Montes Claros. We calculated the rates of domicile infestation, relative abundance of Lu. longipalpis, and Lu. longipalpis distribution in each site, capture location (intra- and peridomestic locations) and area (intervention and non-intervention areas). FINDINGS: In the control area in Fortaleza, the relative abundance of Lu. longipalpis was 415 specimens at each capture site, whereas in the intervention area it was 159.25; in Montes Claros, the relative abundance was 5,660 specimens per capture site in the control area, whereas in the intervention area it was 2,499.4. The use of dog collars was associated with a reduction in captured insects of 15% (p = 0.004) and 60% (p < 0.001) in Montes Claros and Fortaleza, respectively. MAIN CONCLUSIONS: We observed a lower vector abundance in the intervention areas, suggesting an effect of the insecticide-impregnated collars.

Validation and reliability of the rapid diagnostic test 'SD Bioeasy Dengue Duo' for dengue diagnosis in Brazil: a phase III study.

BACKGROUND: The diagnosis of dengue is complex. Until recently, only specialised laboratories were able to confirm dengue infection. However, this has changed with the newly available immunochromatographic rapid tests. Early diagnosis is of great interest, and point-of-care rapid tests have been increasingly used in Brazil. Most of those tests have not undergone validation in the Brazilian population. In this context, we decided to evaluate a rapid test introduced in the Federal District (FD). OBJECTIVES: To estimate the accuracy and reliability of the SD Bioeasy Dengue Duo rapid test and its components to detect dengue infections in a consecutive sample of symptomatic residents in the FD, Brazil. METHODS: In total, 1353 venous blood samples were collected between 2013 and 2014. Two hundred and six positive samples (cases) and 246 negative samples (non cases) were required for sensitivity and specificity estimation, respectively; for agreement evaluation, we used 401 samples. The reference standard used was a composite of MAC-ELISA, virus isolation and real-time polymerase chain reaction (RT-qPCR). The evaluation was conducted prospectively under field conditions in the public health units of the FD. FINDINGS: The results for the overall accuracy of the rapid test (NS1/IgM combined) showed 76% sensitivity and 98% specificity. The sensitivity for the NS1 component (67%) was better than that for the IgM component (35%). The positive likelihood ratio was 46, and the negative likelihood ratio was 0.24. The reliability of the test (NS1/IgM combined) demonstrated crude agreement of 98% (Kappa index 0.94). MAIN CONCLUSIONS: The present phase III, large-scale validation study demonstrates that the rapid test SD Bioeasy Dengue Duo has moderate sensitivity (NS1/IgM combined) and high specificity. Therefore, the test is useful in confirming the diagnosis of dengue, but not enough to rule out the diagnosis. Our results also suggest that Dengue virus (DENV) viral load estimated through the RT-qPCR and antibody level measured through the MAC-ELISA could have had a direct influence on the accuracy of the rapid test.

Cost of visceral leishmaniasis care in Brazil.

OBJECTIVE: To estimate the Brazilian direct and indirect costs of human visceral leishmaniasis (VL) in 2014. METHODS: Cost-of-illness study on the Brazilian public health system and societal perspective. VL cases registered in the Notifiable Diseases Information System in the year of 2014 were considered. Direct medical costs regarding diagnostic, treatment and care provided to patients with VL were estimated through the top-down approach. The indirect costs related to productivity loss due to premature mortality and morbidity were estimated by means of the human-capital method. RESULTS: In 2014, 9895 suspected cases of VL were reported in the Notifiable Diseases Information System, and 3453 were later confirmed. There were 234 patients with Leishmania-HIV coinfection underwent a secondary prophylaxis. The total cost of VL in Brazil was US$ 14 190 701.50 (US$ 14 189 150.10 to 14 199 940.53) that varied according to the sensitivity analysis. The total of direct medical costs corresponded to US$ 1 873 681.96 (US$1 872 130.55 to 1 882 920.99), and the majority of costs was associated with hospitalisation (40%), followed by treatment (22%), and secondary prophylaxis (18%). Productivity loss corresponded to US$ 11 421 683.37 for premature mortality and US$ 895 336.18 for work absence due to hospitalisation by the illness. CONCLUSIONS: VL represents an expensive health problem for the Brazilian public health system and society, mainly because of its productivity loss due to premature mortality. Interventions to reduce VL lethality could have a great impact on decreasing the cost of illness.

Rapid diagnostic test for G6PD deficiency in Plasmodium vivax-infected men: a budget impact analysis based in Brazilian Amazon.

OBJECTIVE: The aim of this study was to estimate the incremental budget impact (IBI) of a rapid diagnostic test to detect G6PDd in male patients infected with Plasmodium vivax in the Brazilian Amazon, as compared with the routine protocol recommended in Brazil which does not include G6PDd testing. METHODS: The budget impact analysis was performed from the perspective of the Brazilian health system, in the Brazilian Amazon for the years 2013, 2014 and 2015. The analysis used a decision model to compare two scenarios: the first consisting of the routine recommended in Brazil which does not include prior diagnosis of dG6PD, and the second based on the use of RDT CareStart™ G6PD (CS-G6PD) in all male subjects diagnosed with vivax malaria. The expected implementation of the diagnostic test was 30% in the first year, 70% the second year and 100% in the third year. RESULTS: The analysis identified negative IBIs which were progressively smaller in the 3 years evaluated. The sensitivity analysis showed that the uncertainties associated with the analytical model did not significantly affect the results. CONCLUSION: A strategy based on the use of CS-G6PD would result in better use of public resources in the Brazilian Amazon.

Effect of piplartine and cinnamides on Leishmania amazonensis, Plasmodium falciparum and on peritoneal cells of Swiss mice.

CONTEXT: Plants of the Piperaceae family produce piplartine that was used to synthesize the cinnamides. OBJECTIVE: To assess the effects of piplartine (1) and cinnamides (2-5) against the protozoa responsible for malaria and leishmaniasis, and peritoneal cells of Swiss mice. MATERIALS AND METHODS: Cultures of Leishmania amazonensis, Plasmodium falciparum-infected erythrocytes, and peritoneal cells were incubated, in triplicate, with different concentrations of the compounds (0 to 256 µg/mL). The inhibitory concentration (IC50) in L. amazonensis and cytotoxic concentration (CC50) in peritoneal cell were assessed by the MTT method after 6 h of incubation, while the IC50 for P. falciparum-infected erythrocytes was determined by optical microscopy after 48 or 72 h of incubation; the Selectivity Index (SI) was calculated by CC50/IC50. RESULTS: All compounds inhibited the growth of microorganisms, being more effective against P. falciparum after 72 h of incubation, especially for the compounds 1 (IC50 = 3.2 µg/mL) and 5 (IC50 = 6.6 µg/mL), than to L. amazonensis (compound 1 = 179.0 µg/mL; compound 5 = 106.0 µg/mL). Despite all compounds reducing the viability of peritoneal cells, the SI were <10 to L. amazonensis, whereas in the cultures of P. falciparum the SI >10 for the piplartine (>37.4) and cinnamides 4 (>10.7) and 5 (= 38.4). DISCUSSION AND CONCLUSION: The potential of piplartine and cinnamides 4 and 5 in the treatment of malaria suggest further pre-clinical studies to evaluate their effects in murine malaria and to determine their mechanisms in cells of the immune system.

Sensitivity and specificity of parallel or serial serological testing for detection of canine Leishmania infection.

In Brazil, human and canine visceral leishmaniasis (CVL) caused by Leishmania infantum has undergone urbanisation since 1980, constituting a public health problem, and serological tests are tools of choice for identifying infected dogs. Until recently, the Brazilian zoonoses control program recommended enzyme-linked immunosorbent assays (ELISA) and indirect immunofluorescence assays (IFA) as the screening and confirmatory methods, respectively, for the detection of canine infection. The purpose of this study was to estimate the accuracy of ELISA and IFA in parallel or serial combinations. The reference standard comprised the results of direct visualisation of parasites in histological sections, immunohistochemical test, or isolation of the parasite in culture. Samples from 98 cases and 1,327 noncases were included. Individually, both tests presented sensitivity of 91.8% and 90.8%, and specificity of 83.4 and 53.4%, for the ELISA and IFA, respectively. When tests were used in parallel combination, sensitivity attained 99.2%, while specificity dropped to 44.8%. When used in serial combination (ELISA followed by IFA), decreased sensitivity (83.3%) and increased specificity (92.5%) were observed. Serial testing approach improved specificity with moderate loss in sensitivity. This strategy could partially fulfill the needs of public health and dog owners for a more accurate diagnosis of CVL.

Serological diagnosis of canine visceral leishmaniasis in Brazil: systematic review and meta-analysis.

OBJECTIVE: To evaluate the quality and accuracy of serological diagnosis of canine visceral leishmaniasis in the Americas. METHODS: A systematic review found original studies in the databases MEDLINE, EMBASE and LILACS up to November 2012 and in complementary sources up to February 2013. Studies were evaluated in accordance with QUADAS 2 and STARD parameters and recommended in accordance with GRADE parameters. Meta-analysis was carried out with Meta-DiSc software, using the random-effect model. RESULTS: Two hundred and eighty-four studies were identified, of which 25 met the inclusion criteria, comprising the final synthesis. All but one was conducted in Brazil, and only two were judged to be of good quality. 15 studies involving immuno-enzymatic tests with crude antigens (cELISA), 11 studies on indirect immunofluorescence tests (IFAT) and three on the immunochromatographic dual-path platform (DPP) test were meta-analysed. The combined results for sensitivity and specificity were cELISA: 0.89 (CI 95% 0.87-0.91) and 0.87 (CI 95% 0.86-0.88); IFAT: 0.88 (CI 95% 0.85-0.91) and 0.63 (CI 95% 0.61-0.65); and DPP: 0.83 (CI 95% 0.78-0.88) and 0.73 (CI 95% 0.70-0.75). CONCLUSION: Enzyme-linked immunosorbent assay with crude antigens and DPP tests have moderate accuracy for the diagnosis of canine visceral leishmaniasis, and the quality of the design, implementation and analysis of validation studies on diagnostic tests for this disease urgently require improvement. The recommendation for use of the evaluated tests is based on evidence that is scarce and restricted to Brazil.

Successful isolation of Leishmania infantum from Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) collected from naturally infected dogs.

BACKGROUND: The main transmission route of Leishmania infantum is through the bites of sand flies. However, alternative mechanisms are being investigated, such as through the bites of ticks, which could have epidemiological relevance. The objective of this work was to verify the presence of Leishmania spp. in Rhipicephalus sanguineus sensu lato collected from naturally infected dogs in the Federal District of Brazil. METHODS: Ticks were dissected to remove their intestines and salivary glands for DNA extraction and the subsequent amplification of the conserved region of 120 bp of kDNA and 234 bp of the hsp70 gene of Leishmania spp. The amplified kDNA products were digested with endonucleases HaeIII and BstUI and were submitted to DNA sequencing. Isolated Leishmania parasites from these ticks were analyzed by multilocus enzyme electrophoresis, and the DNA obtained from this culture was subjected to microsatellite analyses. RESULTS: Overall, 130 specimens of R. sanguineus were collected from 27 dogs. Leishmania spp. were successfully isolated in culture from five pools of salivary glands and the intestines of ticks collected from four dogs. The amplified kDNA products from the dog blood samples and from the tick cultures, when digested by HaeIII and BstUI, revealed the presence of L. braziliensis and L. infantum. One strain was cultivated and characterized as L. infantum by enzyme electrophoresis. The amplified kDNA products from the blood of one dog showed a sequence homology with L. braziliensis; however, the amplified kDNA from the ticks collected from this dog showed a sequence homology to L. infantum. CONCLUSION: The results confirm that the specimens of R. sanguineus that feed on dogs naturally infected by L. infantum contain the parasite DNA in their intestines and salivary glands, and viable L. infantum can be successfully isolated from these ectoparasites.

Leishmania (Viannia) naiffi: rare enough to be neglected?

In the Brazilian Amazon, American tegumentary leishmaniasis (ATL) is endemic and presents a wide spectrum of clinical manifestations due, in part, to the circulation of at least seven Leishmania species. Few reports of Leishmania (Viannia) naiffi infection suggest that its occurrence is uncommon and the reported cases present a benign clinical course and a good response to treatment. This study aimed to strengthen the clinical and epidemiological importance of L. (V.) naiffi in the Amazon Region (Manaus, state of Amazonas) and to report therapeutic failure in patients infected with this species. Thirty Leishmania spp samples isolated from cutaneous lesions were characterised by multilocus enzyme electrophoresis. As expected, the most common species was Leishmania (V.) guyanensis (20 cases). However, a relevant number of L. (V.) naiffi patients (8 cases) was observed, thus demonstrating that this species is not uncommon in the region. No patient infected with L. (V.) naiffi evolved to spontaneous cure until the start of treatment, which indicated that this species may not have a self-limiting nature. In addition, two of the patients experienced a poor response to antimonial or pentamidine therapy. Thus, either ATL cases due to L. (V.) naiffi cannot be as uncommon as previously thought or this species is currently expanding in this region.

Specificity of the rapid rK39 antigen-based immunochromatographic test Kalazar Detect(r) in patients with cutaneous leishmaniasis in Brazil.

The aim of this study was to evaluate the specificity of a rapid immunochromatographic test that was developed to detect antibodies against the rK39 antigen for the diagnosis of visceral leishmaniasis (VL). This evaluation was performed using sera from patients with a confirmed diagnosis of active cutaneous leishmaniasis. The sera from 272 patients with a confirmed diagnosis of localised cutaneous leishmaniasis (CL) who resided in an area endemic for Leishmania braziliensis in Brazil were obtained before the initiation of antileishmanial treatment. Kalazar Detect(r)(InBios, Seattle, WA) recombinant K39 antigen-based immunochromatographic strips were used according to the manufacturer's instructions. The test results were evaluated independently by two examiners in sequential order. The positive controls for the test included five serum samples from five patients with parasitologically confirmed diagnosis of VL caused by Leishmania infantum in Brazil. Overall, 100% of the samples obtained from patients with CL were negative, confirming the absence of a serological cross-reaction for individuals with cutaneous disease when these patients were evaluated using the rapid test. The lack of a cross-reaction in patients who were infected by parasites of the same genus highlights the specificity of the rK39 antigen for the diagnosis of VL in areas with the sympatric circulation of L. braziliensis and L. infantum.

Prevalence and Associated Factors of Post-COVID-19 Syndrome in a Brazilian Cohort after 3 and 6 Months of Hospital Discharge.

(1) Objectives: To evaluate the frequency and factors associated with the Post-COVID-19 Syndrome (PCS) in COVID-19 survivors after 3 and 6 months of hospital discharge; (2) Methods: We conducted a cohort study with patients who were hospitalized with COVID-19 in a referral public hospital in Brasília, Federal District, Brazil. After 3 and 6 months of discharge, patients answered a questionnaire about PCS symptoms. Poisson regression with robust variance was used to estimate the crude and adjusted prevalence ratios (PR and aPR) of PCS. (3) Results: The prevalence of PCS was 81% and 61% after 3 and 6 months of hospital discharge, respectively. The main symptoms after 3 months of discharge were hair loss (44%), fatigue (42%), and memory loss (39%); while after 6 months, they were memory loss (29%) and fatigue (27%). In the multivariate analysis, the main factor associated with PCS was female gender (aPR): 1.28 (1.16-1.41) and 1.60 (1.34-1.90), 3 and 6 months after hospital discharge, respectively. Hypercholesterolemia was also associated with PCS after 3 months aPR of 1.15 (1.04-1.27). After 6 months of discharge, obesity [aPR: 1.22 (1.03-1.45)] and pronation [aPR: 1.15 (1.06-1.25)] were relevant associated factors. (4) Conclusions: The prevalence of PCS was high in COVID-19 survivors who had the moderate and severe forms of the disease. Memory loss was the most persistent symptom. Our data pointed to female gender, hypercholesterolemia, obesity, and pronation during hospitalization as relevant PCS-associated risk factors.

SARS CoV-2 seroprevalence and diagnostic accuracy during a COVID-19 outbreak in a major penitentiary complex in Brazil, June to July 2020.

PURPOSE: This study aims to estimate the overall SARS-CoV-2 seroprevalence and evaluate the accuracy of an antibody rapid test compared to a reference serological assay during a COVID-19 outbreak in a prison complex housing over 13,000 prisoners in Brasília. DESIGN/METHODOLOGY/APPROACH: The authors obtained a randomized, stratified representative sample of each prison unit and conducted a repeated serosurvey among prisoners between June and July 2020, using a lateral-flow immunochromatographic assay (LFIA). Samples were also retested using a chemiluminescence enzyme immunoassay (CLIA) to compare SARS-CoV-2 seroprevalence and 21-days incidence, as well as to estimate the overall infection fatality rate (IFR) and determine the diagnostic accuracy of the LFIA test. FINDINGS: This study identified 485 eligible individuals and enrolled 460 participants. Baseline and 21-days follow-up seroprevalence were estimated at 52.0% (95% CI 44.9-59.0) and 56.7% (95% CI 48.2-65.3) with LFIA; and 80.7% (95% CI 74.1-87.3) and 81.1% (95% CI 74.4-87.8) with CLIA, with an overall IFR of 0.02%. There were 78.2% (95% CI 66.7-89.7) symptomatic individuals among the positive cases. Sensitivity and specificity of LFIA were estimated at 43.4% and 83.3% for IgM; 46.5% and 91.5% for IgG; and 59.1% and 77.3% for combined tests. ORIGINALITY/VALUE: The authors found high seroprevalence of anti-SARS-CoV-2 antibodies within the prison complex. The occurrence of asymptomatic infection highlights the importance of periodic mass testing in addition to case-finding of symptomatic individuals; however, the field performance of LFIA tests should be validated. This study recommends that vaccination strategies consider the inclusion of prisoners and prison staff in priority groups.