Identification of a new 2-amino acid insertion in the integrase coding region of HIV-1 subtype G isolates.

Amino acid insertions have been rarely found in the integrase (IN) coding region of Human immunodeficiency virus 1 (HIV-1), and have been considered as natural polymorphisms. It is still unclear the potential impact of these insertion mutations on the viral replication capacity and/or susceptibility to integrase strand transfer inhibitors (INSTIs). The objective of this study was to describe a previously unreported amino acid insertion in the IN coding region of HIV-1 isolates obtained from antiretroviral treatment-naïve infected individuals. Nucleotide sequences of HIV-1 isolates obtained from two infected individuals were analyzed for genotypic resistance to antiretroviral drugs. Phylogenetic inference was carried out for HIV-1 genetic variant identification. An unreported insertion of a threonine (T) and an asparagine (N) between codon 255 and 256 (S255N_TN) was identified in the IN C-terminal domain of HIV-1 subtype G isolates. No resistance-associated mutations to INSTIs were detected in the inserted sequences. Both individuals maintained undetectable HIV-1 RNA viral load, 24 months after undergoing antiretroviral treatment with an INSTI containing regimen. The results demonstrated the possibility of transmission of this insertion mutation and suggested that the codon 255 insert by itself may not affect susceptibility to INSTIs.

Clearance and persistence of SARS-CoV-2 RNA in patients with COVID-19.

Patients with coronavirus disease-2019 may be discharged based on clinical resolution of symptoms, and evidence for viral RNA clearance from the upper respiratory tract. Understanding the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral clearance profile is crucial to establish a re-testing plan on discharge and ending isolation of patients. We aimed to evaluate the number of days that a patient needed to achieve undetectable levels of SARS-CoV-2 in upper respiratory tract specimens (nasopharyngeal swab and/or an oropharyngeal swab). The clearance and persistence of viral RNA was evaluated in two groups of positive patients: those who achieved two negative reverse transcription-polymerase chain reaction (RT-PCR) tests and those who kept testing positive. Patients were organized thereafter in two subgroups, mild illness patients discharged home and inpatients who had moderate to severe illness. Results from RT-PCR tests were then correlated with results from the evaluation of the immune response. The study evidenced that most patients tested positive for more than 2 weeks and that persistence of viral RNA is not necessarily associated with severe disease but may result from a weaker immune response instead.

Ultrasonography of Hands and Wrists in the Diagnosis of Complications of Chikungunya Fever.

The purpose of this series was to describe the ultrasonographic and radiographic manifestations of changes to the hands and wrists in 50 patients with chronic musculoskeletal symptoms secondary to Chikungunya fever during the 2016 outbreak that occurred in Rio de Janeiro, Brazil. Most of the plain radiographs were normal (62%). The most common ultrasonographic findings were small joint synovitis (84%), wrist synovitis (74%), finger tenosynovitis (70%), and cellulitis (50%). In most cases, power Doppler did not show an increase in synovial vascular flow. The plain radiographs showed no specific findings, whereas the ultrasound images revealed synovial compromise and neural thickening.

Seroprevalence of Protective Antibodies Against Influenza and the Reduction of the Influenza Incidence Rate: An Annual Repeated Cross-Sectional Study From 2014 to 2019.

BACKGROUND: Seroepidemiological studies provide estimates of population-level immunity, prevalence/incidence of infections, and evaluation of vaccination programs. We assessed the seroprevalence of protective antibodies against influenza and evaluated the correlation of seroprevalence with the cumulative annual influenza incidence rate. METHODS: We conducted an annual repeated cross-sectional seroepidemiological survey, during June-August, from 2014 to 2019, in Portugal. A total of 4326 sera from all age groups, sex, and regions was tested by hemagglutination inhibition assay. Seroprevalence and geometric mean titers (GMT) of protective antibodies against influenza were assessed by age group, sex, and vaccine status (65+ years old). The association between summer annual seroprevalence and the difference of influenza incidence rates between one season and the previous one was measured by Pearson correlation coefficient (r). RESULTS: Significant differences in seroprevalence of protective antibodies against influenza were observed in the population. Higher seroprevalence and GMT for A(H1N1)pdm09 and A(H3N2) were observed in children (5-14); influenza B seroprevalence in adults 65+ was 1.6-4.4 times than in children (0-4). Vaccinated participants (65+) showed significant higher seroprevalence/GMT for influenza. A strong negative and significant correlation was found between seroprevalence and ILI incidence rate for A(H1N1)pdm09 in children between 5 and 14 (r = -0.84; 95% CI, -0.98 to -0.07); a weak negative correlation was observed for A(H3N2) and B/Yamagata (r ≤ -0.1). CONCLUSIONS: The study provides new insight into the anti-influenza antibodies seroprevalence measured in summer on the ILI incidence rate in the next season and the need for adjusted preventive health care measures to prevent influenza infection and transmission.

Prevalence of etravirine resistance associated mutations in HIV-1 strains isolated from infected individuals failing efavirenz: comparison between subtype B and non-B genetic variants.

Etravirine (ETR) is a non-nucleoside analogue reverse transcriptase inhibitor (NNRTI) with a high genetic barrier to the development of resistance and with potential activity against Human immunodeficiency virus type 1 (HIV-1) strains resistant to first-generation NNRTIs. The objective of this study was to investigate the prevalence of ETR resistance associated mutations (RAMs) in HIV-1 strains isolated from infected individuals failing efavirenz (EFV), as well as to evaluate possible differences in the distribution of ETR RAMs between subtype B and non-B genetic variants. Nucleotide sequences of the protease and partial reverse transcriptase (RT) coding regions of the pol gene of 55 HIV-1 strains isolated from infected individuals failing EFV on regular follow-up at a reference center in Portugal, were retrospectively analyzed. The most prevalent ETR RAMs observed were L100I, V90I, and K101E, with a prevalence of 16.4% (n = 9), 9.1% (n = 5), and 5.5% (n = 3), respectively. Overall, 47.3% (n = 26) of the nucleotide sequences had at least one ETR RAM: 38.2% (n = 21) had one ETR RAM, 7.3% (n = 4) had two ETR RAMs and 1.8% (n = 1) had three ETR RAMs. No statistically significant differences were found in the distribution of ETR RAMs between subtype B and non-B genetic variants. The results demonstrate that ETR rescue therapy is a viable option in treatment-experienced individuals failing EFV and suggests that ETR may be equally useful in HIV-1 infections caused by different genetic variants.

Epidemiology and genetic variability of respiratory syncytial virus in Portugal, 2014-2018.

INTRODUCTION: Respiratory syncytial virus (RSV) is associated with substantial morbidity and mortality since it is a predominant viral agent causing respiratory tract infections in infants, young children and the elderly. Considering the availability of the RSV vaccines in the coming years, molecular understanding in RSV is necessary. OBJECTIVE: The objective of the present study was to describe RSV epidemiology and genotype variability in Portugal during the 2014/15-2017/18 period. MATERIAL AND METHODS: Epidemiological data and RSV-positive samples from patients with a respiratory infection were collected through the non-sentinel and sentinel influenza surveillance system (ISS). RSV detection, subtyping in A and B, and sequencing of the second hypervariable region (HVR2) of G gene were performed by molecular methods. Phylogenetic trees were generated using the Neighbor-Joining method and p-distance model on MEGA 7.0. RESULTS: RSV prevalence varied between the sentinel (2.5%, 97/3891) and the non-sentinel ISS (20.7%, 3138/16779), being higher (P < 0.0001) among children aged <5 years. Bronchiolitis (62.9%, 183/291) and influenza-like illness (24.6%, 14/57) were associated (P < 0.0001) with RSV laboratory confirmation among children aged <6 months and adults ≥65 years, respectively. The HVR2 was sequenced for 562 samples. RSV-A (46.4%, 261/562) and RSV-B (53.6%, 301/562) strains clustered mainly to ON1 (89.2%, 233/261) and BA9 (92%, 277/301) genotypes, respectively, although NA1 and BA10 were also present until 2015/2016. CONCLUSION: The sequence and phylogenetic analysis reflected the relatively high diversity of Portuguese RSV strains. BA9 and ON1 genotypes, which have been circulating in Portugal since 2010/2011 and 2011/2012 respectively, predominated during the whole study period.

Cross-protection to new drifted influenza A(H3) viruses and prevalence of protective antibodies to seasonal influenza, during 2014 in Portugal.

INTRODUCTION: Immune profile for influenza viruses is highly changeable over time. Serological studies can assess the prevalence of influenza, estimate the risk of infection, highlight asymptomatic infection rate and can also provide data on vaccine coverage. The aims of the study were to evaluate pre-existing cross-protection against influenza A(H3) drift viruses and to assess influenza immunity in the Portuguese population. MATERIALS AND METHODS: We developed a cross-sectional study based on a convenience sample of 626 sera collected during June 2014, covering all age groups, both gender and all administrative health regions of Portugal. Sera antibody titers for seasonal and new A(H3) drift influenza virus were evaluated by hemagglutination inhibition assay (HI). Seroprevalence to each seasonal influenza vaccine strain virus and to the new A(H3) drift circulating strain was estimated by age group, gender and region and compared with seasonal influenza-like illness (ILI) incidence rates before and after the study period. RESULTS: Our findings suggest that seroprevalences of influenza A(H3) (39.9%; 95% CI: 36.2-43.8) and A(H1)pdm09 (29.7%; 95% CI: 26.3-33.4) antibodies were higher than for influenza B, in line with high ILI incidence rates for A(H3) followed by A(H1)pdm09, during 2013/2014 season. Low pre-existing cross-protection against new A(H3) drift viruses were observed in A(H3) seropositive individuals (46%). Both against influenza A(H1)pdm09 and A(H3) seroprotection was highest in younger than 14-years old. Protective antibodies against influenza B were highest in those older than 65years old, especially for B/Yamagata lineage, 33.3% (95% CI: 25.7-41.9). Women showed a high seroprevalence to influenza, although without statistical significance, when compared to men. A significant decreasing trend in seroprotection from north to south regions of Portugal mainland was observed. CONCLUSIONS: Our results emphasize that low seroprotection increases the risk of influenza infection in the following winter season. Seroepidemiological studies can inform policy makers on the need for vaccination and additional preventive measures.

Detection of the protease codon 35 amino acid insertion in sequences from treatment-naïve HIV-1 subtype C infected individuals in the Central Region of Portugal.

BACKGROUND: Amino acids insertions in the protease (PR) coding region have been reported in protease inhibitors (PIs) treatment-naïve and experienced HIV-1 infected individuals ranging from 0.1% to 4.55% and have been rarely found in non-B HIV-1 subtype strains. OBJECTIVES: To investigate the presence of amino acid insertions in the PR coding region in sequences from treatment-naïve HIV-1 infected individuals in the Central Region of Portugal. STUDY DESIGN: Sequences of the pol gene from 260 treatment-naïve HIV-1 infected individuals between 2000 and 2008 were analyzed and phylogenetic analysis was performed. RESULTS: A threonine insertion (E35E_T) was detected in 2.69% (n=7) of the sequences analyzed and all the sequences that possessed this insertion were identified as subtype C. All the seven inserted sequences clustered in the same lineage of the phylogenetic tree. Heterosexual and intravenous drug use were found to be the routes of infection. No major mutations in the PR coding region associated with resistance to PIs were detected. CONCLUSIONS: It was found the highest prevalence of PR codon 35 insertion among treatment-naïve HIV-1 infected individuals ever reported in the western countries. Epidemiological data and Phylogenetic analysis indicated the possibility of transmission of this insertion. The results suggested that these inserted strains have normal susceptibility to PIs containing regimens. This study demonstrated the spreading epidemic of PR codon 35 inserted strains from subtype C in the Central Region of Portugal, during the past eight years.