Susceptibility of Aedes aegypti populations to pyriproxyfen in the Federal District of Brazil

Abstract INTRODUCTION: In Brasilia, pyriproxyfen (PPF; 0.01 mg/L) has been used for the larval control of Aedes aegypti mosquitoes since 2016. Information on the susceptibility of Ae. aegypti to PPF, and the development of resistance in populations from the Federal District of Brazil (FD) is limited. It is essential to monitor the susceptibility of Ae. aegypti to insecticides in order to improve vector control strategies. This study aimed to evaluate the susceptibility of Ae. aegypti populations from five areas of Brasilia to PPF. METHODS: We performed dose-response tests to estimate the emergence inhibition and resistance ratio of each field population, including the Rockefeller reference population. We also analyzed egg positivity, and the density and mortality of larvae and pupae. RESULTS: Populations from Vila Planalto (RR50=1.7), Regiment Guards Cavalry (RR50=2.5), and Sub-secretary of Justice Complex (RR50=3.7) presented high susceptibility to PPF, while the RR values of populations from Lago Norte (RR50=7.7) and Varjão (RR50=5.9) were moderately high, suggesting the emergence of insipient resistance to PPF in Brasilia. At 30 ng/mL, the highest larvae mortality rate was 2.7% for the population from Lago Norte, while that of pupae was 92.1% for Varjão and Vila Planalto. CONCLUSIONS: The five populations of Ae. aegypti from the FD are susceptible to PPF and there is a need to monitor the susceptibility of Ae. aegypti in new areas of the FD.

Hepatitis C: sexual or intrafamilial transmission? Epidemiological and phylogenetic analysis of hepatitis C virus in 24 infected couples / Hepatite C: transmissão sexual ou intrafamiliar? Análise epidemiológica e filogenética do vírus da hepatite C em 24 casais infectados

The role of sexual or intrafamilial transmission of hepatitis C is controversial. A phylogenetic analysis was performed on the non-structural region 5B of the hepatitis C virus (NS5B-HCV). High percentages of homology (mean of 98.3 percent) were shown between the couples. Twenty (83.3 percent) of the 24 men but only two of the women (8.3 percent) reported having had sexually transmitted diseases during their lives. The risk factors for HCV acquisition were blood transfusion (10 couples), use of illegal injected drugs (17), use of inhalants (15), acupuncture (5) and tattoos (5). The shared use of personal hygiene items included toothbrushes between six couples (25 percent), razor blades between 16 (66.7 percent), nail clippers between 21 (87.5 percent) and manicure pliers between 14 (58.3 percent). The high degree of similarity of the hepatitis C virus genome supports the hypothesis of hepatitis C virus transmission between these couples. The shared use of personal hygiene items suggests the possibility of intrafamilial transmission of infection.

O papel da transmissão sexual ou intrafamiliar da hepatite C é controverso. Foi feita análise filogenética, região não estrutural 5B do vírus da hepatite C (NS5B-HCV). Altas percentagens de homologia com média de 98,3 por cento foi revelada entre os casais. Vinte (83,3 por cento) de 24 homens, contra apenas duas (8,3 por cento) mulheres reportaram doença sexualmente transmisível durante suas vidas. Os fatores de risco para aquisição da doença foram: transfusão de sangue para 10 casais, uso de drogas ilícitas injetáveis para 17, inalatórias para 15, acupuntura em 5 e tatuagens para 5. O compartilhamento de utensílios de higiene pessoal incluem: escova de dente para seis (25 por cento) dos casais, lâmina de barbear para 16 (66,7 por cento), cortador de unhas para 21 (87,5 por cento) e alicate de manicure para 14 (58,3 por cento). O alto grau de similaridade genômica entre os vírus da hepatite C suporta a hipótese de transmissão entre os casais. O uso compartilhado de utensílios de higiene pessoal sugere a possibilidade de transmissão intrafamiliar.

Cost-effectiveness of entecavir versus lamivudine for the suppression of viral replication in chronic hepatitis B patients in Brazil

Hepatitis B virus infection is an important public-health issue. Chronic patients have a higher risk of death due to complications, which increases health-care expenses in. Cost-effectiveness analysis of entecavir (ETV) versus lamivudine (LVD) for treatment of chronic hepatitis B, in e antigen (AgHBe)-positive and negative patients, based on two phase 3, controlled and randomized studies. A decision analysis model was developed, using the following endpoints: cost per patient with undetectable viral load and cost per quality life year (QALY) gained. Risks for complications (compensated or decompensated cirrhosis and hepatocellular carcinoma) were based on the cohort study REVEAL, published in 2006. The REVEAL parameters were applied to the results of the viral load levels obtained from the clinical assay data. The complication costs were based on a study of the disease cost conducted in Brazil, in 2005. The cost data were obtained predominantly from Sistema Único de Saúde [SUS - Brazilian public health system] payment tables and drug price lists. The utility data were obtained from literature and life expectancy information was based on IBGE data. The analysis perspective was that of SUS. A discount rate of 3 percent per year was used. For the horizon of time of 10 years, the ETV had an incremental cost of approximately two million Brazilian Reais (R$) compared to LVD. Reducing the number of complications, ETV treatment reduced costs by around 3 million, reducing final costs by 1 million, for AgHBe-positive patients. ETV also reduced the incremental cost per QALY gained. ETV was found to be the most cost-effective alternative for AgHBe-positive and negative patients.

Detection of HCV by PCR in serum and PBMC of patients with hepatitis C after treatment

Although hepatitis C is mainly hepatotropic, some studies suggest that hepatitis C virus (HCV) infects peripheral blood mononuclear cells (PBMC), using them as a reservoir, which might contribute to the development of resistance to treatment. Fifty-four hepatitis-C patients, who had been submitted to treatment, were selected. Blood samples were collected on the same day for the detection of HCV RNA in serum and PBMC by PCR, using the Amplicor HCV 2.0 assay (Roche Diagnostics). HCV genotyping was performed using the INNO-LiPA HCV kit (Versant, Bayer Diagnostics). HCV RNA was detected in both serum and PBMC in 35 (64 percent) patients and no RNA in 16 (29.6 percent). Disagreement between the serum and PBMC results was observed for three patients (5.6 percent), with HCV RNA being detected in PBMC but not in serum. Four months later, new serum and PBMC samples were collected from one of these patients and HCV RNA was detected in both samples, showing that PBMC can reveal signs of a lack of response to treatment. We conclude that the absence of HCV in the serum of patients with chronic hepatitis C by the end of treatment does not mean that there is no circulating virus. HCV in mononuclear cells may be an indicator of the persisting infection.

Hepatitis C treatment: shorter and better?

Herein, we present a synthesis of two publications that evaluate an abbreviated therapeutic approach to treating chronic hepatitis C virus (HCV) infection. Based on those publications, we discuss the use of the early virologic response (EVR) as a tool for the optimized management of patients under treatment, as well as reviewing concepts of HCV viral kinetics. The fourth-week EVR, characterized by HCV RNA dropping to undetectable levels, allows individuals infected with HCV genotype 1 and presenting low baseline viral loads to be treated with the combination of pegylated interferon and ribavirin for 24 weeks, whereas individuals infected with HCV genotypes 2 or 3 can be treated for only 12 weeks. Therefore, by adopting abbreviated treatment regimens optimized through early prediction of sustained viral response, it is possible to increase the number of patients treated without incurring the excess costs related to high rates of treatment failure and management of adverse outcomes, as well as avoiding the risks of unnecessarily exposing patients to drugs that have the potential to be highly toxic.

Weight-based combination therapy with peginterferon alpha-2b and ribavirin for Naïve, relapser and non-responder patients with chronic hepatitis C

Combination therapy with pegylated interferon and ribavirin is considered the new standard therapy for naïve patients with chronic hepatitis C. We evaluated the efficacy and safety of treatment with weight-based peginterferon alpha-2b (1.5 mg/kg per week) plus ribavirin (800-1,200 mg/day) for 48 weeks in naïve, relapser and non-responder (to previous treatment with interferon plus ribavirin) patients with chronic hepatitis C. Sixty-seven naïve, 26 relapser and 40 non-responder patients were enrolled. The overall sustained virological response (SVR) for the intention-to-treat population was 54 percent for naïve, 62 percent for relapser and 38 percent for non-responder patients. In the naïve subgroup, SVR was significantly higher in patients with the non-1 genotype (67 percent) compared to those with genotype 1 (45 percent). In relapsers and non-responders, SVR was, respectively, 69 percent and 24 percent in patients with genotype 1 and 43 percent and 73 percent in those with genotype non-1. There were no significant differences in SVR rates among the three body weight ranges (< 65 kg, 65-85 kg and > 85 kg) in any of the subgroups. Early virological response (EVR) was reached by 78 percent, 81 percent and 58 percent of naïve, relapser and non-responder patients, respectively, and among those with EVR, 63 percent, 67 percent and 61 percent, respectively, subsequently achieved SVR. All of the non-responder patients who did not have EVR reached SVR. Treatment was discontinued in 13 percent of the patients, due to loss to follow-up, hematological abnormalities or depression.

Estudo da cinética viral do vírus da hepatite C em pacientes co-infectados com o HIV / HCV knetics among HIV co-infected patients

Pacientes co-infectados VHC/HIV ( n=26 ) receberam PegIFN A2A e Ribavirina por 48 semanas . Coletamos 20 amostras para quantificação do HCV ( TaqMan® ) - horas 0,4,8,12,18,24,30,36,42,48, dias 3,4,7,8,15,22,29,43,57 e semana 12 – e do HIV após o início da terapia.Dados basais/ Twenty six co-infected patients were treated with PegIFN A2A and Ribavirin for 48 weeks. Twenty samples were drew at hours 0,4,8,12,18,24,30,36,42,48, days 3,4,7,8,22,29,43,57, week 12 to HIV and HCV ( TaqMan® ) quantification after start medication. Basal data...

Co-infecçao HIV-Hepatite. Co-infeccao HIV/HCV: Interações recíprocas / Co-infection HIV-Hepatitis. Co-infection HIV-HCV: mutual interactions

A era do HAART que propiciou uma maior sobrevivencia aos portadores do HIV, descortinou o problema da co-infeccao HIV/HCV. O tema e sem duvida dos mais desafiadores e relevantes. A co-infeccao é uma prioridade assistencial muito clara, em particular por se categorizar como uma doenca oportuna, dada sua maior prevalencia e maior gravidade entre portadores do HIV

Hepatitis C viral load does not predict disease outcome: going beyond numbers

The analysis of 58 patients with chronic hepatitis C without cirrhosis and treated with interferon-alpha demonstrated that hepatitis C viral (HCV) load does not correlate with the histological evolution of the disease (p = 0.6559 for architectural alterations and p = 0.6271 for the histological activity index). Therefore, the use of viral RNA quantification as an evolutive predictor or determinant of the severity of hepatitis C is incorrect and of relative value. A review of the literature provided fundamental and interdependent HCV (genotype, heterogeneity and mutants, specific proteins), host (sex, age, weight, etc) and treatment variables (dosage, time of treatment, type of interferon) within the broader context of viral kinetics, interferon-mediated immunological response (in addition to natural immunity against HCV) and the role of interferon as a modulator of fibrogenesis. Therefore, viral load implies much more than numbers and the correct interpretation of these data should consider a broader context depending on multiple factors that are more complex than the simple value obtained upon quantification