Recombinant protein KR95 as an alternative for serological diagnosis of human visceral leishmaniasis in the Americas.

In the Americas, visceral leishmaniasis (VL) is caused by the protozoan Leishmania infantum, leading to death if not promptly diagnosed and treated. In Brazil, the disease reaches all regions, and in 2020, 1,933 VL cases were reported with 9.5% lethality. Thus, an accurate diagnosis is essential to provide the appropriate treatment. Serological VL diagnosis is based mainly on immunochromatographic tests, but their performance may vary by location, and evaluation of diagnostic alternatives is necessary. In this study, we aimed to evaluate the performance of ELISA with the scantily studied recombinant antigens, K18 and KR95, comparing their performance with the already known rK28 and rK39. Sera from parasitologically confirmed symptomatic VL patients (n = 90) and healthy endemic controls (n = 90) were submitted to ELISA with rK18 and rKR95. Sensitivity (95% CI) was, respectively, 83.3% (74.2-89.7) and 95.6% (88.8-98.6), and specificity (95% CI) was 93.3% (85.9-97.2) and 97.8% (91.8-99.9). For validation of ELISA with the recombinant antigens, we included samples from 122 VL patients and 83 healthy controls collected in three regions in Brazil (Northeast, Southeast, and Midwest). When comparing the results obtained with the VL patients' samples, significantly lower sensitivity was obtained by rK18-ELISA (88.5%, 95% CI: 81.5-93.2) compared with rK28-ELISA (95.9%, 95% CI: 90.5-98.5), but the sensitivity was similar comparing rKR95-ELISA (95.1%, 95% CI: 89.5-98.0), rK28-ELISA (95.9%, 95% CI: 90.5-98.5), and rK39-ELISA (94.3%, 95% CI: 88.4-97.4). Analyzing the specificity, it was lowest with rK18-ELISA (62.7%, 95% CI: 51.9-72.3) with 83 healthy control samples. Conversely, higher and similar specificity was obtained by rKR95-ELISA (96.4%, 95% CI: 89.5-99.2), rK28-ELISA (95.2%, 95% CI: 87.9-98.5), and rK39-ELISA (95.2%, 95% CI: 87.9-98.5). There was no difference in sensitivity and specificity across localities. Cross-reactivity assessment, performed with sera of patients diagnosed with inflammatory disorders and other infectious diseases, was 34.2% with rK18-ELISA and 3.1% with rKR95-ELISA. Based on these data, we suggest using recombinant antigen KR95 in serological assays for VL diagnosis.

Anosmia in the course of COVID-19: A case report.

RATIONALE: A sudden onset of anosmia has been recently recognized as a symptom of coronavirus disease (COVID-19). PATIENT CONCERNS: Here, we describe a case of complete anosmia in a young male with COVID-19. Although he had fever and odynophagia, no abnormalities were observed in his nasopharyngeal mucosa, suggesting that his anosmia resulted from olfactory neuropathy. DIAGNOSES: COVID-19 was confirmed by RNA detection in nasopharyngeal swab specimen. INTERVENTIONS: The patient received olfactory training and B complex vitamins. OUTCOMES: On day 30, the patient reported complete recovery of his sense of smell. LESSONS: As early diagnosis is fundamental to control the spread of COVID-19 infection, we emphasize that anosmia identified in febrile cases during the COVID-19 epidemic may be a symptom indicative of the disease. Moreover, COVID-19-related anosmia can be completely reversible.

Correction: Performance of rK39-based immunochromatographic rapid diagnostic test for serodiagnosis of visceral leishmaniasis using whole blood, serum and oral fluid.

[This corrects the article DOI: 10.1371/journal.pone.0230610.].

Performance of rK39-based immunochromatographic rapid diagnostic test for serodiagnosis of visceral leishmaniasis using whole blood, serum and oral fluid.

BACKGROUND: The development of rK39-based immunochromatographic rapid diagnostic tests represents an important advance for serodiagnosis of visceral leishmaniasis, being cheap and easy to use at the point of care (POC). Although the use of rK39 have considerably improved the sensitivity and specificity of serological tests compared with total antigens, great variability in sensitivity and specificity was reported. This study aimed at the evaluation of "Kalazar Detect™ Rapid Test, Whole Blood" (Kalazar Detect RDT) for Visceral Leishmaniasis (VL) diagnosis using oral fluid, whole blood and serum specimens collected at different endemic areas of VL of Brazil. METHODOLOGY: To evaluate Kalazar Detect RDT, oral fluid, whole blood and serum specimens from 128 VL patients, 85 healthy individuals, 22 patients with possible cross-reactivity diseases and 20 VL/aids coinfected patients were collected and assayed at the POC. PRINCIPAL FINDINGS AND CONCLUSIONS: The performance of Kalazar Detect RDT in whole blood and serum was similar; however, using oral fluid, the sensitivity was low. Particularly in samples from the city of Natal, Rio Grande do Norte state in Northeastern Brazil, we observed low sensitivity, 80.0% (95% CI: 62.7-90.5), using whole blood and serum, and poor sensitivity, 43.3% (95% CI: 27.4-60.8) with oral fluid. Those values were much lower than in the other regions, where sensitivity ranged from 92.7-96.3% in whole blood and serum, and 80.0-88.9% in oral fluid. Besides, in VL/aids coinfected patients, lower sensitivity was achieved compared with VL patients. In samples from Natal, the sensitivity was 0.0% (95% CI: 0.0-49.0) and 25.0% (95% CI: 4.6-69.9), using oral fluid and serum/whole blood, respectively; in samples from the other regions, the sensitivity ranged from 40.0-63.6% and 80.0-81.8%, respectively. As for specificity, high values were observed across the fluids, 100.0% (95% CI: 96.5-100.0) in whole blood, 96.3% (95% CI: 90.8-98.5) in serum, and 95.3% (95% CI: 89.5-98.0) in oral fluid; across localities, specificity ranged from 85.7-100.0%. Serum samples sent by the collaborating centers to Instituto de Medicina Tropical (n = 250) were tested by Kalazar Detect RDT, Direct Agglutination Test, Indirect immunofluorescence assay, Enzyme-linked immunosorbent assay, and IT-Leish® RDT. The regional difference in the performance of rK39-based RDT and lower sensitivity in Leishmania/HIV coinfected patients raise concern on the routine use of these products for the diagnosis of VL.

Late diagnosis: a factor associated with death from visceral leishmaniasis in elderly patients.

INTRODUCTION: Visceral leishmaniasis (VL) is among the seven global endemic diseases assigned a high priority by the World Health Organization. In Latin America, most cases occur in Brazil. Despite the availability of intensive treatment resources and protocols for specific treatment, lethality rates for VL have increased in several regions in the country over the past 10 years, particularly in patients under one and over 50 years of age. As the growth of the elderly population accelerates in Brazil, VL poses a greater challenge to public health. Given the scarcity of studies addressing the disease in this age group, the purpose of this study was to identify factors associated with VL lethality among the elderly. METHODS/KEY FINDINGS: This analytical, cross-sectional epidemiological study comprised 80 elderly patients who sought treatment at the teaching hospital of the Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil, in the period 2000-2013.Clinical, laboratory and treatment variables were investigated from records of elderly patients with VL diagnosis confirmed by at least one laboratory test positive (culture for parasite or direct parasitological examination; reactive immunofluorescence; immunochromatographic test with recombinant antigens) or patients without laboratory confirmation who lived in endemic areas and responded favorably to therapeutic trial, as defined by the Brazilian Ministry of Health. Of the 80 patients included, 78 tested positive to at least one exam; in two cases, diagnosis was based on clinical and epidemiological criteria. The lethality rate was 20%. Multivariate analysis revealed an association between death and time elapsed from symptom onset.

Pertussis in the central-west region of Brazil: one decade study.

In many parts of the world, numerous outbreaks of pertussis have been described despite high vaccination coverage. In this article we report the epidemiological characteristics of pertussis in Brazil using a Surveillance Worksheet. Secondary data of pertussis case investigations reported from January 1999 to December 2008 recorded in the Information System for Notifiable Diseases (SINAN) and the Central Laboratory for Public Health (LACEN-MS) were utilized. The total of 561 suspected cases were reported and 238 (42.4%) of these were confirmed, mainly in children under six months (61.8%) and with incomplete immunization (56.3%). Two outbreaks were detected. Mortality rate ranged from 2.56% to 11.11%. The occurrence of outbreaks and the poor performance of cultures for confirming diagnosis are problems which need to be addressed. High vaccination coverage is certainly a good strategy to reduce the number of cases and to reduce the impact of the disease in children younger than six months.

HIV and HCV coinfection: prevalence, associated factors and genotype characterization in the Midwest Region of Brazil.

A cross-sectional study on prevalence, associated factors and genotype distribution of HCV infection was conducted among 848 HIV-infected patients recruited at reference centers in the Midwest Region of Brazil. The prevalence rate of HIV-HCV coinfection was 6.9% (95% CI: 5.2 to 8.6). In multivariable analysis, increasing age, use of illicit drugs (injection and non-injection), a history of blood transfusion before 1994, and the absence of a steady partnership were significant independent associated factors for HIV-HCV coinfection. The phylogenetic analysis based on the NS5B region revealed the presence of two major circulating genotypes of HCV: genotypes 1 (58.3%) and 3 (41.7%). The prevalence of HIV-HCV coinfection was lower than those reported in studies conducted with HIV-infected patients in different regions of Brazil, due to the fact that illicit drug use is not a frequent mode of HIV transmission in this region of Brazil. Serologic screening of HIV-patients for HCV before initiating antiretroviral treatment, a comprehensive identification of associated factors, and the implementation of effective harm reduction programs are highly recommended to provide useful information for treatment and to prevent HCV coinfection in these patients.

Pertussis in the central-west region of Brazil: one decade study

In many parts of the world, numerous outbreaks of pertussis have been described despite high vaccination coverage. In this article we report the epidemiological characteristics of pertussis in Brazil using a Surveillance Worksheet. Secondary data of pertussis case investigations reported from January 1999 to December 2008 recorded in the Information System for Notifiable Diseases (SINAN) and the Central Laboratory for Public Health (LACEN-MS) were utilized. The total of 561 suspected cases were reported and 238 (42.4%) of these were confirmed, mainly in children under six months (61.8%) and with incomplete immunization (56.3%). Two outbreaks were detected. Mortality rate ranged from 2.56% to 11.11%. The occurrence of outbreaks and the poor performance of cultures for confirming diagnosis are problems which need to be addressed. High vaccination coverage is certainly a good strategy to reduce the number of cases and to reduce the impact of the disease in children younger than six months.

Hiv and hcv coiffection: prevalence, associatedfactors and genotype characteriization in the midwest region of Brazil / Coinfecção HIV e HCV: prevalência, fatores associados e caracterização dos genótipos na Região Centro-Oeste do Brasil

A cross-sectional study on prevalence, associated factors and genotype distribution of HCV infection was conducted among 848 HIV-infected patients recruited at reference centers in the Midwest Region of Brazil. The prevalence rate of HIV-HCV coinfection was 6.9% (95% CI: 5.2 to 8.6). In multivariable analysis, increasing age, use of illicit drugs (injection and non-injection), a history of blood transfusion before 1994, and the absence of a steady partnership were significant independent associated factors for HIV-HCV coinfection. The phylogenetic analysis based on the NS5B region revealed the presence of two major circulating genotypes of HCV: genotypes 1 (58.3%) and 3 (41.7%). The prevalence of HIV-HCV coinfection was lower than those reported in studies conducted with HIV-infected patients in different regions of Brazil, due to the fact that illicit drug use is not a frequent mode of HIV transmission in this region of Brazil. Serologic screening of HIV-patients for HCV before initiating antiretroviral treatment, a comprehensive identification of associated factors, and the implementation of effective harm reduction programs are highly recommended to provide useful information for treatment and to prevent HCV coinfection in these patients.

Estudo transversal sobre a prevalência, fatores associados e distribuição dos genótipos do HCV foi realizado em 848 pacientes infectados pelo HIV, recrutados em centros de referência na Região Centro-Oeste do Brasil. A taxa de prevalência de coinfecção HIV-HCV foi de 6,9% (IC 95%: 5,2-8,6). Na análise multivariada, o aumento da idade, o uso de drogas ilícitas (injetáveis e não injetáveis), história de transfusão de sangue antes de 1994, e ausência de companheiro constante foram fatores associados independentes e significativos para a coinfecção HIV-HCV. A análise filogenética baseada na região NS5B revelou a presença de dois principais genótipos do HCV em circulação: genótipos 1 (58,3%) e 3 (41,7%). A prevalência da coinfecção HIV-HCV foi menor do que as relatadas em estudos realizados com pacientes infectados pelo HIV em diferentes regiões do Brasil, devido ao fato de que o uso de drogas ilícitas não é modo frequente de transmissão do HIV neste Estado do Brasil. Triagem sorológica de pacientes HIV-positivos para HCV antes de iniciar o tratamento antirretroviral, identificação completa dos fatores associados e a implementação de programas eficazes de redução de danos são altamente recomendados para fornecer informações úteis, para o tratamento e para evitar a coinfecção com HCV nestes pacientes.