Differential Frequencies of HLA-DRB1, DQA1, and DQB1 Alleles and Haplotypes Are Observed in the Arbovirus-Related Neurological Syndromes

BACKGROUND

We took advantage of the 2015-2016 Brazilian arbovirus outbreak (Zika [ZIKV]/dengue/chikungunya viruses) associated with neurological complications to type HLA-DRB1/DQA1/DQB1 variants in patients exhibiting neurological complications and in bone marrow donors from the same endemic geographical region.

METHODS

DRB1/DQA1/DQB1 loci were typed using sequence-specific oligonucleotides. In silico studies were performed using X-ray resolved dimer constructions.

RESULTS

The DQA1*01, DQA1*05, DQB1*02, or DQB1*06 genotypes/haplotypes and DQA1/DQB1 haplotypes that encode the putative DQA1/DQB1 dimers were overrepresented in the whole group of patients and in patients exhibiting peripheral neurological spectrum disorders (PSD) or encephalitis spectrum disorders (ESD). The DRB1*04, DRB1*13, and DQA1*03 allele groups protected against arbovirus neurological manifestation, being underrepresented in whole group of patients and ESD and PSD groups. Genetic and in silico studies revealed that DQA1/DQB1 dimers (1) were primarily associated with susceptibility to arbovirus infections; (2) can bind to a broad range of ZIKV peptides (235 of 1878 peptides, primarily prM and NS2A); and (3) exhibited hydrophilic and highly positively charged grooves when compared to the DRA1/DRB1 cleft. The protective dimer (DRA1/DRB1*04) bound a limited number of ZIKV peptides (40 of 1878 peptides, primarily prM).

CONCLUSION

Protective haplotypes may recognize arbovirus peptides more specifically than susceptible haplotypes.

Peripheral spectrum neurological disorder after arbovirus infection is associated with HLA-F variants among Northeastern Brazilians

INTRODUCTION

Non-classical class I human leukocyte antigens (HLA) molecules are known to modulate the function of cytotoxic cells (NK and T CD8+) during viral infection by interacting with inhibitory/activating receptors. However, little is known about the HLA-E/-F genetic variability on arbovirus infections.

METHODS

We evaluated by massive parallel sequencing the full HLA-E/-F genetic diversity among patients infected during the arbovirus (ZIKV, DENV, and CHIKV) outbreak leading to a broad range of neurological complications in the Brazilian State of Pernambuco. In parallel, healthy blood donors from the same area were also studied. Plink and R software were used for genetic association study. To limit the false-positive results and enhance the reliability of the results, we adopted P-values <0.01 as significant levels.

RESULTS

Compared to controls, the HLA-F alleles: -1610 C (rs17875375), +1383 G (rs17178385), and +3537 A (rs17875384), all in complete linkage disequilibrium with each other (r² = 1), were overrepresented in patients presenting peripheral spectrum disorders (PSD). The HLA-F*Distal-D haplotype that harbored the -1610 C allele exhibited a trend increase in PSD group. No associations were found for HLA-E.

CONCLUSIONS

Our findings showed that the HLA-F genetic background seems to be more important than HLA-E on the susceptibility to PSD complications.

Knowledge, attitudes and practices on tuberculosis transmission and prevention among auxiliary healthcare professionals in three Brazilian high-burden cities: a cross-sectional survey

Background

Tuberculosis elimination requires treatment of latently infected high-risk persons, such as contacts of index cases. Identification and referral of tuberculosis contacts for investigation are major barriers in the contact cascade-of-care. These tasks rely heavily on auxiliary primary healthcare workers in many low- and middle-income countries. We aimed to understand their knowledge, attitudes and practices (KAP) regarding contact investigation in Brazil.

Methods

We conducted a cross-sectional KAP survey on tuberculosis transmission and prevention among 135 auxiliary healthcare workers in three tuberculosis high-burden Brazilian cities. Trained interviewers applied a translated version of a previously applied questionnaire. Open answers were classified in pre-defined objective categories and analysed quantitatively. Answers were further classified as satisfactory or not according to criteria set by a panel of three specialists.

Results

Although 66% had received tuberculosis training in the past 10 years, only 19% were trained for tuberculosis prevention. 64% could not clearly distinguish latent tuberculosis infection (LTBI) from active tuberculosis; 63% did not know how to diagnose LTBI and 52% did not know how to prevent progression to active tuberculosis. Most believed that it is important to investigate adult (99%) and child (96%) contacts for LTBI. However, not all invite contacts - children (81%) or adults (71%) - to the clinic, despite only 24% perceiving difficulties for investigation.

Conclusions

Gaps in KAP among auxiliary health workers have been reported in other areas, such as obstetrics and other infectious diseases. To the best of our knowledge, this is the first KAP survey on tuberculosis transmission and prevention among auxiliary health care workers, and relevant gaps were also found. Knowledge gaps were notably related to LTBI management, including how to recognize it and prevent progression to active tuberculosis through treatment, despite most recognizing the importance of investigating contacts. Auxiliary healthcare workers in three Brazilian high-burden cities have important knowledge gaps despite their perception of the importance of tuberculosis prevention among contacts. They need to incorporate contact referral as one of their tasks to enable progress toward the target of tuberculosis elimination.

Electronic supplementary material

The online version of this article (10.1186/s12913-019-4231-x) contains supplementary material, which is available to authorized users.

Knowledge about tuberculosis transmission and prevention and perceptions of health service utilization among index cases and contacts in Brazil: Understanding losses in the latent tuberculosis cascade of care

Introduction

Tuberculosis contacts are candidates for active and latent tuberculosis infection screening and eventual treatment. However, many losses occur in the different steps of the contacts’ cascade of care. Reasons for this are poorly understood.

Objective

To describe the different steps where losses in the contact cascade occur and to explore knowledge and attitudes regarding tuberculosis transmission/prevention and perceptions about tuberculosis services in order to understand the reasons for losses from the tuberculosis service users’ perspective.

Design

We collected routine data from the index case and contact registry books and from patients’ records to build the cascade of care of contacts in 12 health facilities in three Brazilian cities with high tuberculosis incidence rates. During a knowledge, attitudes and practices (KAP) survey, trained interviewers administered a semi-structured questionnaire to 138 index cases and 98 contacts.

Results

Most of the losses in the cascade occurred in the first two steps (contact identification, 43% and tuberculin skin testing placement, 91% of the identified contacts). Among KAP-interviewed contacts, 67% knew how tuberculosis is transmitted, 87% knew its key symptoms and 81% declared they would take preventive therapy if prescribed. Among KAP-interviewed index cases, 67% knew they could spread tuberculosis, 70% feared for the health of their families and 88% would like their family to be evaluated in the same services.

Conclusion

Only a small proportion of contacts are evaluated for active and latent tuberculosis, despite their—and their index cases’—reasonable knowledge, positive attitudes towards prevention and satisfaction with tuberculosis services. In these services, education of service users would not be a sufficient solution. Healthcare workers’ and managers’ perspective, not explored in this study, may bring more light to this subject.

Evaluation of four molecular methods for the diagnosis of tuberculosis in pulmonary and blood samples from immunocompromised patients

The present study analysed the concordance among four different molecular diagnostic methods for tuberculosis (TB) in pulmonary and blood samples from immunocompromised patients. A total of 165 blood and 194 sputum samples were collected from 181 human immunodeficiency virus (HIV)-infected patients with upper respiratory complaints, regardless of suspicious for TB. The samples were submitted for smear microscopy, culture and molecular tests: a laboratory-developed conventional polymerase chain reaction (PCR) and real-time quantitative PCR (qPCR) and the Gen-Probe and Detect-TB Ampligenix kits. The samples were handled blindly by all the technicians involved, from sample processing to results analysis. For sputum, the sensitivity and specificity were 100% and 96.7% for qPCR, 81.8% and 94.5% for Gen-Probe and 100% and 66.3% for Detect-TB, respectively. qPCR presented the best concordance with sputum culture [kappa (k) = 0.864)], followed by Gen-Probe (k = 0.682). For blood samples, qPCR showed 100% sensitivity and 92.3% specificity, with a substantial correlation with sputum culture (k = 0.754) and with the qPCR results obtained from sputum of the corresponding patient (k = 0.630). Conventional PCR demonstrated the worst results for sputa and blood, with a sensitivity of 100% vs. 88.9% and a specificity of 46.3% vs. 32%, respectively. Commercial or laboratory-developed molecular assays can overcome the difficulties in the diagnosis of TB in paucibacillary patients using conventional methods available in most laboratories.

Association of biomarkers with atherosclerosis and risk for coronary artery disease in patients with HIV

BACKGROUND

The massive use of Highly-Active Antiretroviral Therapy (HAART) in individuals with human immunodeficiency virus (HIV) coincided with an increase in cardiovascular disease, a major cause of morbidity and mortality in this group.

OBJECTIVE

To determine the frequency of carotid atherosclerosis and the association between biomarker levels and carotid intimal-medial thickening in HIV-positive individuals treated for HIV at referral centers in Pernambuco.

METHODS

This was a cross-sectional study of 122 HIV-positive patients. Subclinical carotid atherosclerosis was considered with the presence of increased intimal-medial thickness of the common carotid artery > 0.8 mm or plaques in the carotid ultrasound. The following inflammatory biomarkers were analyzed: IL6, IL1-β, TNF-α, high-sensitivity CRP, sVCAM-1 and sICAM-1.

RESULTS

Of the 122 patients analyzed, most were men (60.7%) aged > 40 years (57.4%) receiving HAART (81.1%). The prevalence of atherosclerosis was 42.6% (52 cases). Patients older than 40 years and intermediate or high Framingham score were more likely to develop atherosclerosis at the univariate analysis. Age older than 40 years (OR = 6.57, 95%CI: 2.66 to 16.2, p = 0.000), male gender (OR = 2.76, 95%CI: 1.12 to 6.79, p = 0.027) and presence of syndrome metabolic (OR = 2.27, 95%CI: 0.94 to 5.50, p = 0.070) were associated with atherosclerosis at the multivariate analysis. Elevated levels of inflammatory cytokines and adhesion molecules were not associated with the presence of atherosclerosis.

CONCLUSION

There was no association between inflammatory biomarkers, adhesion molecules and presence of carotid atherosclerosis. However, a higher chance of subclinical atherosclerosis was observed in men, those older than 40 years, with intermediate / high Framingham score or metabolic syndrome.