Outbreak of extensively drug-resistant Serratia marcescens in an intensive care unit

We present the investigation and control of an extensively drug-resistant Serratia marcescens outbreak in a 30-bed intensive care unit (ICU). Within 6 weeks, 4 critically ill trauma patients were infected by the same strain. Intensive containment measures limited the spread of this strain while sustaining the capacity of the trauma ICU.

Immunogenicity and safety of inactivated quadrivalent influenza vaccine compared with the trivalent vaccine for influenza infection: an overview of systematic reviews

BACKGROUND

Influenza infection is a highly preventable transmissible viral disease associated with mild upper respiratory symptoms and more severe conditions such as lethal pneumonia. Studies have shown that a broader spectrum influenza vaccine could reduce influenza's burden of disease in low- and middle-income countries. A considerable number of systematic reviews reported that quadrivalent influenza vaccines are considered more effective compared to trivalent vaccines, hence, there is a need for an overview in order to synthesize the current evidence pertaining to the comparison between quadrivalent and trivalent inactivated influenza vaccines.

OBJECTIVE

The aim was to summarize the evidence from systematic reviews that investigated the immunogenicity and safety of the Influenza's inactivated quadrivalent vaccine (QIV) compared to the trivalent vaccine (TIV), in the general population.

METHODS

We searched articles up to December 2022 at: Web of Science, EMBASE, MEDLINE, Cochrane Library, and SCOPUS. The search strategy was conducted following the PICO model. We included systematic reviews comparing the primary outcomes of immunogenicity (seroprotection rate and seroconversion rate) and adverse events using risk ratios. The AMSTAR 2 and ROBIS were used for quality assessments, and GRADE was used for evidence certainty assessments.

FINDINGS

We included five systematic reviews, totalling 47,740 participants. The Quadrivalent Inactivated Influenza Vaccine (QIV) exhibited enhanced immunogenicity in the context of B-lineage mismatch when compared to the Trivalent Inactivated Influenza Vaccine (TIV). While the safety profile of QIV was found to be comparable to that of TIV, the QIV showed a higher incidence of solicited local pain among children and adolescents, as well as an increased frequency of local adverse events within the adult population.

CONCLUSION

Our findings suggest that the QIV provides a superior immunogenicity response compared to the TIV in all age groups evaluated, especially when a lineage mismatch occurred. The safety of QIV was considered similar to the TIV, with no serious or systemic solicited or unsolicited adverse events; tough pain at the injection site was greater for QIV. We recommend caution owing to the high risk of bias in the selection process and no protocol registration.

A randomized, double-blind, non-inferiority trial comparing the immunogenicity and safety of two seasonal inactivated influenza vaccines in adults

BACKGROUND

To enhance the production and availability of influenza vaccines in different regions of the world is paramount to mitigate the global burden of this disease. Instituto Butantan developed and manufactured an embryonated egg-based inactivated split-virion trivalent seasonal influenza vaccine as part of a technology transfer partnership with Sanofi Pasteur.

METHODS

This is a phase IV, randomized, double-blind, active-controlled, multicenter clinical trial including adults 18-60 and > 60 years recruited during the 2019 southern hemisphere influenza season. Subjects were randomized 1:1 to receive either the Sanofi Pasteur Trivalent Seasonal Influenza Vaccine (SP-TIV) or Instituto Butantan Trivalent Seasonal Influenza Vaccine (IB-TIV). Hemagglutinin inhibition antibody titers were assessed pre-vaccination and 21 days post-vaccination.

RESULTS

624 participants were randomized and vaccinated. In both intention-to-treat and per-protocol analysis, non-inferiority of the SP-TIV versus IB-TIV was demonstrated for the three influenza strains. In the per-protocol analysis, the SP-GMT/IB-GMT ratios for H1N1, H3N2, and B were 0.9 (95%CI, 0.7-1.1), 1.2 (95%CI, 1.0-1.4), and 1.1 (95%CI, 0.9-1.3), respectively. Across vaccination groups, the most common adverse reactions (AR) were limited to the injection-site, including pain and tenderness. The majority of the ARs were graded 1 and/or 2 and lasted less than one day. No serious adverse reaction was observed.

CONCLUSION

This study demonstrated the non-inferiority of the immunogenicity of a single-dose of Instituto Butantan versus a single dose of the Sanofi Pasteur Seasonal Trivalent Influenza Vaccine in adults. Both vaccines were well tolerated and presented similar safety profiles.

Dose-sparing effect of two adjuvant formulations with a pandemic influenza A/H7N9 vaccine: A randomized, double-blind, placebo-controlled, phase 1 clinical trial

The emergence of potentially pandemic viruses has resulted in preparedness efforts to develop candidate vaccines and adjuvant formulations. We evaluated the dose-sparing effect and safety of two distinct squalene-based oil-in-water adjuvant emulsion formulations (IB160 and SE) with influenza A/H7N9 antigen. This phase I, randomized, double-blind, placebo-controlled, dose-finding trial (NCT03330899), enrolled 432 healthy volunteers aged 18 to 59. Participants were randomly allocated to 8 groups: 1A) IB160 + 15μg H7N9, 1B) IB160 + 7.5μg H7N9, 1C) IB160 + 3.75μg H7N9, 2A) SE + 15μg H7N9, 2B) SE + 7.5μg H7N9, 2C) SE + 3.75μg H7N9, 3) unadjuvanted vaccine 15μg H7N9 and 4) placebo. Immunogenicity was evaluated through haemagglutination inhibition (HI) and microneutralization (MN) tests. Safety was evaluated by monitoring local and systemic, solicited and unsolicited adverse events (AE) and reactions (AR) 7 and 28 days after each study injection, respectively, whereas serious adverse events (SAE) were monitored up to 194 days post-second dose. A greater increase in antibody geometric mean titers (GMT) was observed in groups receiving adjuvanted vaccines. Vaccinees receiving IB160-adjuvanted formulations showed the greatest response in group 1B, which induced an HI GMT increase of 4.7 times, HI titers ≥40 in 45.2% of participants (MN titers ≥40 in 80.8%). Vaccinees receiving SE-adjuvanted vaccines showed the greatest response in group 2A, with an HI GMT increase of 2.5 times, HI titers ≥40 in 22.9% of participants (MN titers ≥40 in 65.7%). Frequencies of AE and AR were similar among groups. Pain at the administration site and headache were the most frequent local and systemic solicited ARs. The vaccine candidates were safe and the adjuvanted formulations have a potential dose-sparing effect on immunogenicity against influenza A/H7N9. The magnitude of this effect could be further explored.

Outbreak caused by the SARS-CoV-2 Omicron variant in the psychiatric ward of a general hospital in Brazil

Background:

An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant was detected in the psychiatric ward of a general hospital in Brasília, Brazil.

Methods:

We report the investigation, clinical outcomes, viral sequencing, and control measures applied to outbreak containment.

Results:

The overall attack rate was 95% (23/24) in a period of 13 days. Among the cases, 78% (18/23) were vaccinated and 17% (4/23) required intensive care. The Omicron variant was isolated from the 19 sequenced samples.

Conclusions:

The findings highlight the potential harm that highly transmissible variants may generate among hospitalized populations, particularly those with comorbidities.

IMPLEMENTAÇÃO DE PROGRAMA INFORMATIZADO DE GERENCIAMENTO DE ANTIMICROBIANOS: DESAFIOS DURANTE A PANDEMIA DO COVID-19

A resistência aos antimicrobianos é uma ameaça crescente à saúde pública por aumentar a morbimortalidade, o período de internação e os custos da assistência à saúde. O controle das bactérias multirresistentes se tornou ainda mais desafiador por ocasião da pandemia de COVID-19, com o aumento importante das hospitalizações e da utilização de antimicrobianos. A implementação de um programa de gerenciamento de antimicrobianos busca estabelecer intervenções coordenadas destinadas a otimizar o uso de antimicrobianos, oferecendo um tratamento efetivo e seguro aos pacientes. O Programa Informatizado de Gerenciamento de Antimicrobianos do Hospital de Base do Distrito Federal vem sendo estruturado há dois anos, buscando suprir as necessidades de um hospital público terciário de 711 leitos, sendo 80 leitos de UTI. O programa exige uma abordagem articulada multidisciplinar composta por infectologistas, enfermeiros, farmacêuticos clínicos, microbiologistas e profissionais de tecnologia da informação (TI). O programa é composto de quatro eixos principais: 1) auditoria oportuna das prescrições eletrônicas de antibióticos, 2) tele assessoria para prescrição de antibióticos, 3) educação continuada para prescrição de antibióticos e 4) melhorias em microbiologia. No eixo 1 e 2, a equipe do Núcleo de Controle de Infecção Hospitalar (NCIH) e farmácia clínica atuam nas orientações de uso racional de antimicrobianos e no controle da adesão às mesmas. Os setores de TI e epidemiologia hospitalar desenvolveram conjuntamente os painéis digitais de indicadores de processo e resultado que permitem gerenciar continuamente a eficiência e efetividade do programa. No eixo 3, com base nas avaliações do programa e demandas institucionais, são desenvolvidos treinamentos específicos para as equipes assistentes quanto a prescrição de antimicrobianos. No eixo 4, a microbiologia tem buscado atualizações e melhorias que auxiliem nas decisões sobre uso de antimicrobianos. A pandemia do COVID-19 tornou ainda mais premente e necessária a implantação integral do programa. Mas ao mesmo tempo impôs desafios importantes como implementação de novas áreas e equipes assistenciais, adaptação dos processos a serem realizados à distância, bem como aumento de bactérias MDR associado ao desabastecimento de antibióticos no mercado. O contínuo diálogo entre coordenadores de área e a direção com o apoio da NCIH tem sido determinante para o sucesso da implantação do programa em tempos de pandemia.

COVID-19 in long-term care facilities in Brazil: serological survey in a post-outbreak setting

This cross-sectional seroepidemiological survey presents the seroprevalence of SARS-CoV-2 in a population living in 15 Long-Term Care Facilities (LTCFs), after two intra-institutional outbreaks of COVID-19 in the city of Botucatu, Sao Paulo State, Brazil. Residents were invited to participate in the serological survey performed in June and July 2020. Sociodemographic and clinical characterization of the participants as well as the LTCF profile were recorded. Blood samples were collected, processed and serum samples were tested using the rapid One Step COVID-19 immunochromatography test to detect IgM and IgG anti-SARS-CoV-2. Among 209 residents, the median of age was 81 years old, 135 (64.6%) were female and 171 (81.8%) self-referred as being white. An overall seroprevalence of 11.5% (95% CI: 7.5% – 16.6%) was found. The highest seroprevalences of 100% and 76.9% were observed in LTCFs that had experienced COVID-19 outbreaks. Most residents with positive immunochromatography tests (70.8%) referred previous contact with a confirmed COVID-19 case. Although there was a relatively low seroprevalence of COVID-19 in the total number of elderly people, this population is highly vulnerable and LTCFs are environments at higher risk for COVID-19 dissemination. A well-established test for COVID-19 policies, the adequate characterization of the level of interaction between residents and the healthcare provider team and the level of complexity of care are crucial to monitor and control the transmission of SARS-CoV-2 in these institutions.

Terapia medicamentosa para infecções por coronavírus em humanos: revisão sistemática rápida

Resumo O objetivo deste trabalho foi avaliar efeitos de tratamentos medicamentosos para infecções por coronavírus. Revisão sistemática rápida com buscas nas bases MEDLINE, EMBASE, Cochrane, BVS, Global Index Medicus, Medrix, bioRxiv, Clinicaltrials.gov e International Clinical Trials Registry Platform. Foram incluídos 36 estudos avaliando alternativas medicamentosas contra SARS, SARS-CoV-2 e MERS. A maioria dos estudos incluídos foi conduzida na China com delineamento observacional para tratamento da COVID-19. Os tratamentos mais estudados foram antimaláricos e antivirais. Nos antimaláricos, a metanálise de dois estudos com 180 participantes não identificou benefício da hidroxicloroquina em relação à negativação da carga viral via reação em cadeia de polimerase em tempo real e o uso de antivirais comparado ao cuidado padrão foi similar em relação aos desfechos. As evidências científicas disponíveis são preliminares e de baixa qualidade metodológica, o que sugere cautela na interpretação dos dados. Pesquisas que avaliem a eficácia comparativa em ensaios clínicos randomizados, controlados, com tempo de acompanhamento adequado e com os métodos devidamente divulgados e sujeitos à revisão científica por pares são necessárias. Recomenda-se atualização periódica da presente revisão.

Safety and immunogenicity of the tetravalent, live-attenuated dengue vaccine Butantan-DV in adults in Brazil: a two-step, double-blind, randomised placebo-controlled phase 2 trial

BACKGROUND

The Butantan Institute has manufactured a lyophilised tetravalent live-attenuated dengue vaccine Butantan-DV, which is analogous to the US National Institutes of Health (NIH) TV003 admixture. We aimed to assess the safety and immunogenicity of Butantan-DV.

METHODS

We did a two-step, double-blind, randomised placebo-controlled phase 2 trial at two clinical sites in São Paulo, Brazil. We recruited healthy volunteers aged 18-59 years; pregnant women, individuals with a history of neurological, heart, lung, liver or kidney disease, diabetes, cancer, or autoimmune diseases, and individuals with HIV or hepatitis C were excluded. Step A was designed as a small bridge-study between Butantan-DV and TV003 in DENV-naive participants. In step A, we planned to randomly assign 50 dengue virus (DENV)-naive individuals to receive two doses of Butantan-DV, TV003, or placebo, given 6 months apart. In step B, we planned to randomly assign 250 participants (DENV-naive and DENV-exposed) to receive one dose of Butantan-DV or placebo. Participants were randomly assigned, by computer-generated block randomisation (block sizes of five); participants in step A were randomly assigned (2:2:1) to receive Butantan-DV, TV003, or placebo and participants in step B were randomly assigned (4:1) to receive Butantan-DV or placebo. Participants and study staff were unaware of treatment allocation. The primary safety outcome was the frequency of solicited and unsolicited local and systemic adverse reactions within 21 days of the first vaccination, analysed by intention to treat. The primary immunogenicity outcome was seroconversion rates of the DENV-1-4 serotypes measured 91 days after the first vaccination, analysed in the per-protocol population, which included all participants in step A, and all participants included in step B who completed all study visits with serology sample collection. This trial is registered with ClinicalTrials.gov, NCT01696422.

FINDINGS

Between Nov 5, 2013, and Sept 21, 2015, 300 individuals were enrolled and randomly assigned: 155 (52%) DENV-naive participants and 145 (48%) DENV-exposed participants. Of the 155 DENV-naive participants, 97 (63%) received Butantan-DV, 17 (11%) received TV003, and 41 (27%) received placebo. Of the 145 DENV-exposed participants, 113 (78%) received Butantan-DV, three (2%) received TV003, and 29 (20%) received placebo. Butantan-DV and TV003 were both immunogenic, well-tolerated, and no serious adverse reactions were observed. In step A, rash was the most frequent adverse event (16 [845] of 19 participants in the Butantan-DV group and 13 [76%] of 17 participants in the TV003 group). Viraemia was similar between the Butantan-DV and TV003 groups. Of the 85 DENV-naive participants in the Butantan-DV group who attended all visits for sample collection for seroconversion analysis and thus were included in the per-protocol analysis population, 74 (87%) achieved seroconversion to DENV-1, 78 (92%) to DENV-2, 65 (76%) to DENV-3, and 76 (89%) to DENV-4. Of the 101 DENV-exposed participants in the Butantan-DV group who attended all visits for sample collection for seroconversion analysis, 82 (81%) achieved seroconversion to DENV-1, 79 (78%) to DENV-2, 83 (82%) to DENV-3, and 78 (77%) to DENV-4.

INTERPRETATION

Butantan-DV and TV003 were safe and induced robust, balanced neutralising antibody responses against the four DENV serotypes. Efficacy evaluation of the Butantan-DV vaccine is ongoing.

FUNDING

Intramural Research Program US NIH National Institute of Allergy and Infectious Diseases, Brazilian National Bank for Economic and Social Development, Fundação de Amparo à Pesquisa do Estado de São Paulo, and Fundação Butantan.

Cost-effectiveness of implant-supported dental prosthesis compared to conventional dental prosthesis

OBJECTIVE

To conduct a cost-effectiveness analysis of alternatives for rehabilitation treatment of mandibular edentulism in the context of the Brazilian Unified Health System (implant-supported total dental prosthesis versus conventional total dental prosthesis).

METHODS

A Markov model was developed to capture long-term clinical and economic outcomes. The model’s population was comprised of a hypothetical cohort of 1,000,000 patients, aged 55 years, with total mandibular edentulism and without medical contraindications for performing surgical procedures. The adopted analysis perspective was that of the Brazilian Unified Health System. Based on the proposed model, we calculated cost – in BRL, and effectiveness – measured by quality-adjusted prosthesis year (QAPY). The time horizon of the analysis was 20 years.

RESULTS

Considering a 5% discount in costs and effects, the incremental cost-effectiveness ratio of implant-supported total dental prostheses compared to conventional total dental prosthesis (BRL 464.22/QAPY) was lower than the willingness to pay threshold adopted in the model (BRL 3,050.00/QAPY).

CONCLUSIONS

The results of this economic analysis showed that the rehabilitation of mandibular edentulous patients by implant-supported total prosthesis is very cost-effective when compared to conventional complete prosthesis, considering the cost-effectiveness limits employed.

Mais Médicos: um programa brasileiro em uma perspectiva internacional

A escassez de profissionais de saúde em áreas remotas e vulneráveis é um importante obstáculo para a universalização do acesso à saúde em diversos países. Este artigo examina as políticas de provimento de profissionais de saúde na Austrália, nos Estados Unidos da América e no Brasil. Apesar do sucesso parcial de iniciativas anteriores, foi apenas com o Programa Mais Médicos que a provisão de médicos em áreas vulneráveis teve a magnitude e a resposta em tempo adequado para atender a demanda dos municípios brasileiros. Estão em curso, no país, mudanças quantitativas e qualitativas na formação médica, que buscam garantir não apenas a universalidade, mas, também, a integralidade e sustentabilidade do Sistema Único de Saúde. O êxito dessas iniciativas dependerão da continuidade da articulação interfederativa, de políticas regulatórias de estado, bem como, do constante monitoramento e aprimoramento do programa.

A cross-sectional study of high-risk human papillomavirus clustering and cervical outcomes in HIV-infected women in Rio de Janeiro, Brazil

Background

In Brazil, the rate of cervical cancer remains high despite the availability of screening programs. With ongoing vaccine development and implementation, information on the prevalence of specific HPV types is needed, particularly among high-risk populations, such as HIV-infected women.

Methods

We performed a study of HIV-infected women in Rio de Janeiro, Brazil, who underwent cervical HPV genotype testing between 2005-2013. We examined the prevalence of high-risk HPV types and the patterns of high-risk HPV type clustering. Using logarithmic binomial regression, we estimated the risk of abnormal cytology by HPV genotype result.

Results

Of the 562 women included, 498 (89 %) had at least one HPV type detected. 364 women (65 %) had at least one high-risk HPV type detected and 181 (32 %) had more than one high-risk type detected. HPV 58 was the most frequent HPV type detected overall (prevalence 19.8 % [95 % confidence interval 16.4–23.1]), followed by HPV 53 (prevalence 15.5 % [12.5–18.5]) and HPV 16 (prevalence 13 % [10.2–15.8]). Women infected with more than one high-risk HPV type were younger, had lower CD4+ lymphocyte counts, and were more likely to be infected with HPV 16 or 18. In adjusted analyses, presence of more than one high-risk HPV type was associated with a two-fold increased risk of abnormal cytology after adjusting for presence of individual high-risk type, age, and CD4+ lymphocyte count (adjusted prevalence ratios 1.88–2.07, all p <0.001). No single high-risk HPV type was statistically associated with abnormal cytology after adjusting for the presence of more than one high-risk HPV type.

Conclusions

In the largest study of cervical HPV genotypes among HIV-infected women in Latin America, infection by high-risk HPV types other than 16 or 18 and infection by more than one high-risk HPV types were common. Infection by more than one high-risk type was more strongly associated with abnormal cervical cytology than any individual high-risk HPV type, highlighting the need for multi-valent HPV vaccines.

Influence of CYP19A1 polymorphisms on the treatment of breast cancer with aromatase inhibitors: a systematic review and meta-analysis

BACKGROUND

Many clinical trials have shown the efficacy of aromatase inhibitors (AIs) in the management of breast cancer (BC). There is growing evidence that CYP19A1 single-nucleotide polymorphisms (SNPs) are associated with clinical response (CR) and adverse effects (AEs) among BC patients treated with AIs. The aim of this study was to analyze the association between CYP19A1 polymorphisms and AI treatment in BC patients.

METHODS

A systematic review was performed in MEDLINE, EMBASE, and LILACS. A meta-analysis was conducted to compare the association between CYP19A1 variants and treatment response among BC patients.

RESULTS

A total of 12 studies were included in the final analysis. There was significant variation among the populations studied and the SNPs and outcomes investigated. A meta-analysis was only possible for the evaluation of SNP rs4646 vs. the wild-type variant with respect to time to progression (TTP) among metastatic BC patients treated with AI. TTP was significantly increased in patients with the rs4646 variant compared with the wild-type gene (hazard ratio (HR) = 0.51 [95 % confidence interval (CI), 0.33-0.78], P = 0.002). Seven studies analyzed the association between AEs with different polymorphisms of CYP19A1. Although there was a statistically significant association with musculoskeletal adverse events (rs934635, rs60271534, rs700518rs, and haplotype M_3_5) and with vasomotor symptoms (rs934635, rs1694189, rs7176005, and haplotype M_5_3) in individual studies, similar associations were not observed in further studies. No statistically significant association between musculoskeletal AEs and SNPs rs4646, rs10046, rs727479, and rs1062033 was found.

CONCLUSIONS

These findings suggest that the presence of the rs4646 variant may be a predictive factor of the benefit of AI treatment for BC. The effects of CYP19A1 polymorphisms on clinical outcomes were most often detected in individual studies, suggesting that longer-term studies will better clarify these associations. Additional studies are needed to clarify the predictive value of other SNPs and whether CYP19A1 genotyping should be used to guide AI treatment.

Systematic review of model-based cervical screening evaluations

Background

Optimising population-based cervical screening policies is becoming more complex due to the expanding range of screening technologies available and the interplay with vaccine-induced changes in epidemiology. Mathematical models are increasingly being applied to assess the impact of cervical cancer screening strategies.

Methods

We systematically reviewed MEDLINE®, Embase, Web of Science®, EconLit, Health Economic Evaluation Database, and The Cochrane Library databases in order to identify the mathematical models of human papillomavirus (HPV) infection and cervical cancer progression used to assess the effectiveness and/or cost-effectiveness of cervical cancer screening strategies. Key model features and conclusions relevant to decision-making were extracted.

Results

We found 153 articles meeting our eligibility criteria published up to May 2013. Most studies (72/153) evaluated the introduction of a new screening technology, with particular focus on the comparison of HPV DNA testing and cytology (n = 58). Twenty-eight in forty of these analyses supported HPV DNA primary screening implementation. A few studies analysed more recent technologies - rapid HPV DNA testing (n = 3), HPV DNA self-sampling (n = 4), and genotyping (n = 1) - and were also supportive of their introduction. However, no study was found on emerging molecular markers and their potential utility in future screening programmes. Most evaluations (113/153) were based on models simulating aggregate groups of women at risk of cervical cancer over time without accounting for HPV infection transmission. Calibration to country-specific outcome data is becoming more common, but has not yet become standard practice.

Conclusions

Models of cervical screening are increasingly used, and allow extrapolation of trial data to project the population-level health and economic impact of different screening policy. However, post-vaccination analyses have rarely incorporated transmission dynamics. Model calibration to country-specific data is increasingly common in recent studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1332-8) contains supplementary material, which is available to authorized users.

Cost-Effectiveness Analysis Comparing Chemotherapy Regimens in the Treatment of AIDS-Related Kaposi’s Sarcoma in Brazil

BACKGROUND

Economic analyses of agents used in the treatment of AIDS and opportunistic diseases are particularly important in developing countries.

PURPOSE

To analyze the cost-effectiveness of AIDS-related Kaposi's sarcoma (AIDS-KS) chemotherapy regimens in Brazil.

METHOD

A decision-analysis model was developed, and effectiveness data were derived from randomized phase III trials evaluating pegylated liposomal doxorubicin (PLD), liposomal daunorubicin (DNX), and the ABV regimen (doxorubicin, bleomycin, and vincristine). Resource data on direct medical costs were obtained from local sources.

RESULTS

The cost-effectiveness estimates (defined as average costs per patient who responds completely or partially) favored PLD (US $10,272/responder) in comparison to DNX (US $16,263/responder). Regarding cost-effectiveness, the ABV regimen that is widely used in developing countries had better results when compared to both PLD (US $1,268 vs. US $10,271) and DNX (US $1,268 vs. US $16,260). The incremental cost per additional responder of using PLD instead of ABV was US $20,990. Sensitivity analyses suggest that these results hold over a wide range of assumptions.

CONCLUSION

ABV seems to be the most reasonable treatment option for AIDS-KS patients in resource-limited countries like Brazil.

Uncertainty in environmental health impact assessment: quantitative methods and perspectives

Environmental health impact assessment models are subjected to great uncertainty due to the complex associations between environmental exposures and health. Quantifying the impact of uncertainty is important if the models are used to support health policy decisions. We conducted a systematic review to identify and appraise current methods used to quantify the uncertainty in environmental health impact assessment. In the 19 studies meeting the inclusion criteria, several methods were identified. These were grouped into random sampling methods, second-order probability methods, Bayesian methods, fuzzy sets, and deterministic sensitivity analysis methods. All 19 studies addressed the uncertainty in the parameter values but only 5 of the studies also addressed the uncertainty in the structure of the models. None of the articles reviewed considered conceptual sources of uncertainty associated with the framing assumptions or the conceptualisation of the model. Future research should attempt to broaden the way uncertainty is taken into account in environmental health impact assessments.

Cervical cancer screening among HIV-infected women: an economic evaluation in a middle-income country

Due to the recent widespread availability of highly active antiretroviral therapy (HAART) in middle-income countries, there has been an increase in life expectancy for women on HAART, but no corresponding decrease in cervical cancer incidence. This study evaluates the optimal cervical cancer screening strategy for HIV-infected women in a middle-income country. We developed a mathematical model, which simulates the natural history of the HPV infection, as well as the HIV-mediated immunosupression among women in Brazil. Our model was calibrated using data from the IPEC/FIOCRUZ Women's HIV-infected cohort. The model compares the lifetime effects, costs and cost-effectiveness of strategies combining cytology, HPV DNA test and colposcopy at different screening intervals for different CD4 count strata (27 strategies in total). We found that the strategy with the best cost-effectiveness profile (cost-effectiveness ratio-U$4,911/year of life saved [YLS] and probability of being cost-effective-86%) was HPV testing followed by cytology triage every year for all HIV infected women, considering a very cost-effective threshold given by Brazil's GDP per capita (US$8,625/YLS). The results were robust to changes in the input parameters as demonstrated in one-way, scenario, threshold and probabilistic sensitivity analysis. Our study indicates that annual HPV testing followed by cytology triage for all HIV-infected women is likely to be very cost-effective in a middle-income country like Brazil. The results reflect the synergic effect of using a highly sensitive screening test (HPV DNA test) in sequence with a highly specific test (cytology).

Desempenho do exame citológico e da captura híbrida II no rastreamento de lesões intraepiteliais escamosas de alto grau em mulheres HIV+

As lesões intraepiteliais escamosas de alto grau (HSIL) são precursoras do câncer do colo do útero, com maior risco de ocorrência e desenvolvimento em mulheres HIV+. Neste trabalho, estimamos e comparamos o desempenho do exame citológico e da captura híbrida II no rastreamento das lesões precursoras em mulheres HIV+. A população de estudo compreendeu mulheres acompanhadas na coorte prospectiva aberta do Instituto de Pesquisa Clínica Evandro Chagas da Fundação Oswaldo Cruz (IPEC/Fiocruz). A colposcopia e histologia foram consideradas conjuntamente na definição do teste de referência. O exame citológico apresentou sensibilidade de 31,8% e especificidade de 95,5%, enquanto a captura híbrida II apresentou maior sensibilidade (100%) e menor especificidade (52%). As razões de verossimilhança para o teste positivo e negativo foram estimadas em 7,1 e 0,7 para o exame citológico e em 2,1 e 0,0 para a captura híbrida II, respectivamente.

Dengue vector control strategies in an urban setting: an economic modelling assessment

BACKGROUND

An estimated 2·5 billion people are at risk of dengue. Incidence of dengue is especially high in resource-constrained countries, where control relies mainly on insecticides targeted at larval or adult mosquitoes. We did epidemiological and economic assessments of different vector control strategies.

METHODS

We developed a dynamic model of dengue transmission that assesses the evolution of insecticide resistance and immunity in the human population, thus allowing for long-term evolutionary and immunological effects of decreased dengue transmission. We measured the dengue health burden in terms of disability-adjusted life-years (DALYs) lost. We did a cost-effectiveness analysis of 43 insecticide-based vector control strategies, including strategies targeted at adult and larval stages, at varying efficacies (high-efficacy [90% mortality], medium-efficacy [60% mortality], and low-efficacy [30% mortality]) and yearly application frequencies (one to six applications). To assess the effect of parameter uncertainty on the results, we did a probabilistic sensitivity analysis and a threshold analysis.

FINDINGS

All interventions caused the emergence of insecticide resistance, which, with the loss of herd immunity, will increase the magnitude of future dengue epidemics. In our model, one or more applications of high-efficacy larval control reduced dengue burden for up to 2 years, whereas three or more applications of adult vector control reduced dengue burden for up to 4 years. The incremental cost-effectiveness ratios of the strategies for two high-efficacy adult vector control applications per year was US$615 per DALY saved and for six high-efficacy adult vector control applications per year was $1267 per DALY saved. Sensitivity analysis showed that if the cost of adult control was more than 8·2 times the cost of larval control then all strategies based on adult control became dominated.

INTERPRETATION

Six high-efficacy adult vector control applications per year has a cost-effectiveness ratio that will probably meet WHO's standard for a cost-effective or very cost-effective intervention. Year-round larval control can be counterproductive, exacerbating epidemics in later years because of evolution of insecticide resistance and loss of herd immunity. We suggest the reassessment of vector control policies that are based on larval control only.

FUNDING

The Fulbright Programme, CAPES (Brazilian federal agency for post-graduate education), the Miriam Burnett trust, and the Notsew Orm Sands Foundation.

Calibrating models in economic evaluation: a comparison of alternative measures of goodness of fit, parameter search strategies and convergence criteria

BACKGROUND

The importance of assessing the accuracy of health economic decision models is widely recognized. Many applied decision models (implicitly) assume that the process of identifying relevant values for a model's input parameters is sufficient to prove the model's accuracy. The selection of infeasible combinations of input parameter values is most likely in the context of probabilistic sensitivity analysis (PSA), where parameter values are drawn from independently specified probability distributions for each model parameter. Model calibration involves the identification of input parameter values that produce model output parameters that best predict observed data.

METHODS

An empirical comparison of three key calibration issues is presented: the applied measure of goodness of fit (GOF); the search strategy for selecting sets of input parameter values; and the convergence criteria for determining acceptable GOF. The comparisons are presented in the context of probabilistic calibration, a widely applicable approach to calibration that can be easily integrated with PSA. The appendix provides a user's guide to probabilistic calibration, with the reader invited to download the Microsoft® Excel-based model reported in this article.

RESULTS

The calibrated models consistently provided higher mean estimates of the models' output parameter, illustrating the potential gain in accuracy derived from calibrating decision models. Model uncertainty was also reduced. The chi-squared GOF measure differentiated between the accuracy of different parameter sets to a far greater degree than the likelihood GOF measure. The guided search strategy produced higher mean estimates of the models' output parameter, as well as a narrower range of predicted output values, which may reflect greater precision in the identification of candidate parameter sets or more limited coverage of the parameter space. The broader convergence threshold resulted in lower mean estimates of the models' output, and slightly wider ranges, which were closer to the outputs associated with the non-calibrated approach.

CONCLUSIONS

Probabilistic calibration provides a broadly applicable method that will improve the relevance of health economic decision models, and simultaneously reduce model uncertainty. The analyses reported in this paper inform the more efficient and accurate application of calibration methods for health economic decision models.

Calibrating models in economic evaluation: a seven-step approach

In economic evaluation, mathematical models have a central role as a way of integrating all the relevant information about a disease and health interventions, in order to estimate costs and consequences over an extended time horizon. Models are based on scientific knowledge of disease (which is likely to change over time), simplifying assumptions and input parameters with different levels of uncertainty; therefore, it is sensible to explore the consistency of model predictions with observational data. Calibration is a useful tool for estimating uncertain parameters, as well as more accurately defining model uncertainty (particularly with respect to the representation of correlations between parameters). Calibration involves the comparison of model outputs (e.g. disease prevalence rates) with empirical data, leading to the identification of model parameter values that achieve a good fit. This article provides guidance on the theoretical underpinnings of different calibration methods. The calibration process is divided into seven steps and different potential methods at each step are discussed, focusing on the particular features of disease models in economic evaluation. The seven steps are (i) Which parameters should be varied in the calibration process? (ii) Which calibration targets should be used? (iii) What measure of goodness of fit should be used? (iv) What parameter search strategy should be used? (v) What determines acceptable goodness-of-fit parameter sets (convergence criteria)? (vi) What determines the termination of the calibration process (stopping rule)? (vii) How should the model calibration results and economic parameters be integrated? The lack of standards in calibrating disease models in economic evaluation can undermine the credibility of calibration methods. In order to avoid the scepticism regarding calibration, we ought to unify the way we approach the problems and report the methods used, and continue to investigate different methods.

[Economic evaluation in health: applications in infectious diseases]

The rise in healthcare expenditures due to the incorporation of new diagnostic and therapeutic technologies and increasing life expectancy is a major concern, particularly in developing countries. The role of economic evaluation in health is to optimize the benefits of available resources. This article aims to allow readers to identify the basic characteristics and types of economic evaluation in health and understand its methods, with an emphasis on infectious diseases. We thus review the following concepts: study perspective, analytic scope, costs, and discount rate. We also focus on characteristics of cost-minimization, cost-effectiveness, cost-utility, and cost-benefit analyses, with examples. The article describes the most popular study designs for economic evaluation, discusses different models, and examines the importance of sensitivity analysis. Our final comments address the importance of adopting economic evaluations in health in Brazil.

Economic evaluation of strategies for managing women with equivocal cytological results in Brazil

In Brazil, current management of women with screening results of atypical squamous cells of undetermined significance (ASC-US) is to offer repeat testing at 6-month intervals. Alternative management strategies that have been adopted in many high-income settings are to offer immediate colposcopy referral or to utilise human papillomavirus (HPV) DNA testing as a triage for colposcopy referral, and to consider different strategies according to women's age. The objective of our study was to evaluate the lifetime cost effectiveness in terms of cost per years of life saved (YLS) of these alternative strategies for a middle income setting. A Markov model was developed using data from the Ludwig-McGill cohort and calibrated to independent observational datasets and local cost estimates obtained. In the base-case analysis, repeat cytology was the least costly strategy but also the least effective. Based on the WHO threshold for very cost-effective interventions, HPV triage for women above 30 years-old was the strategy with the highest probability of being cost effective. HPV triage including younger women with ASCUS results would also be a cost-effective option. Whilst there was a slight further gain in effectiveness with immediate colposcopy referral, it was also more expensive and did not appear to be cost effective. Threshold analysis indicated that an HPV test would have to be more than twice as expensive as a cytology test for HPV triage to no longer be cost effective. In conclusion, our results indicate that in middle income settings HPV triage is likely to be the optimal strategy for managing women presenting with ASC-US results.

Comparison of the effectiveness of initial combined antiretroviral therapy with nelfinavir or efavirenz at a university-based outpatient service in Brazil

Since there are some concerns about the effectiveness of highly active antiretroviral therapy in developing countries, we compared the initial combination antiretroviral therapy with zidovudine and lamivudine plus either nelfinavir or efavirenz at a university-based outpatient service in Brazil. This was a retrospective comparative cohort study carried out in a tertiary level hospital. A total of 194 patients receiving either nelfinavir or efavirenz were identified through our electronic database search, but only 126 patients met the inclusion criteria. Patients were included if they were older than 18 years old, naive for antiretroviral therapy, and had at least 1 follow-up visit after starting the antiretroviral regimen. Fifty-one of the included patients were receiving a nelfinavir-based regimen and 75 an efavirenz-based regimen as outpatients. Antiretroviral therapy was prescribed to all patients according to current guidelines. By intention-to-treat (missing/switch = failure), after a 12-month period, 65% of the patients in the efavirenz group reached a viral load <400 copies/mL compared to 41% of the patients in the nelfinavir group (P = 0.01). The mean CD4 cell count increase after a 12-month period was also greater in the efavirenz group (195 x 10(6) cells/L) than in the nelfinavir group (119 x 10(6) cells/L; P = 0.002). The efavirenz-based regimen was superior compared to the nelfinavir-based regimen. The low response rate in the nelfinavir group might be partially explained by the difficulty of using a regimen requiring a higher patient compliance (12 vs 3 pills a day) in a developing country.

Systemic treatment of AIDS-related Kaposi sarcoma: current status and perspectives

Kaposi's sarcoma (KS) is the most frequent type of cancer in patients with Acquired Immune Deficiency Syndrome (AIDS). In the western world, its incidence decreased dramatically in the era of highly active anti-retroviral therapy (HAART). In contrast, the incidence of KS has been steadily climbing in parallel with the AIDS epidemic in Africa over the past 10-15 years, being the most common cancer in adult men in countries like Uganda and Zimbabwe. AIDS-KS can be diagnosed at any stage of HIV infection, although it more commonly occurs in the setting of severe immune suppression, especially with an elevated viral load. Up to now, AIDS-KS is still an incurable disease. Its clinical course is variable, ranging from very indolent cases, requiring no or minimal therapy, to a rapidly progressive disease. Various local therapies are available to control small and asymptomatic lesions, while cytotoxic, immunological and biological therapies can be considered for more aggressive disease. The primary goal of therapy in most of the cases is to provide safe and effective palliation, in order to quality of life. Optimal anti-retroviral therapy is a key component of AIDS-KS management. There are still many questions to be answered in the management of patients with AIDS-KS, such as (1) What are the therapeutic agents that should be used in this disease, and in which sequence? and (2) What are the benefits and risks expected with each treatment option? The aim of this review is to discuss the systemic management of AIDS-KS, with special focus on the above mentioned questions.

Membrane-bound lipoprotein lipase on human monocyte-derived macrophages: localization by immunocolloidal gold technique

Macrophages from both rodent and human sources have been shown to produce lipoprotein lipase (LPL), the enzyme activity of which can be measured in culture media and in cellular homogenates. The studies reported here show the presence of LPL on the surface of human monocyte-derived macrophages. An inhibitory monoclonal antibody to human LPL was used for cellular and immunoelectron microscopy studies. This antibody is a competitive inhibitor of LPL hydrolysis of triacylglycerol but does not inhibit LPL hydrolysis of a water-soluble substrate, p-nitrophenyl acetate. Furthermore, when postheparin plasma was mixed with monoclonal antibody prior to gel filtration on 6% agarose, the LPL activity eluted with the lipoproteins and was not inhibited by the antibody. These studies suggest that the antibody recognized the lipid/lipoprotein binding site of the LPL molecule. Membrane-bound LPL was demonstrated on human monocyte-derived macrophages using colloidal gold-protein A to detect the monoclonal antibody to LPL. The surface colloidal gold was randomly distributed with a surface density of 56,700 gold particles per cell. Control cells cultured in heparin-containing media (10 units/ml) or cells reacted with anti-hepatic triacylglycerol lipase monoclonal IgG or nonimmune mouse IgG did not exhibit membrane binding of protein A-gold. Macrophages were incubated with control and monoclonal anti-LPL IgGs and 125I-labeled anti-mouse IgG F(ab')2. Heparin-releasable membrane-bound anti-LPL antibody was demonstrated. These studies demonstrate the presence of LPL on the surface of human monocyte-derived macrophages, such that the LPL is oriented with its lipid-binding portion (recognized by this antibody) exposed. Membrane-associated LPL may be important in the interaction and subsequent uptake of lipid and lipoproteins by macrophages and in the generation of atherosclerotic foam cells.