Awareness of U = U among Sexual and Gender Minorities in Brazil, Mexico, and Peru: Differences According to Self-reported HIV Status.

The slogan Undetectable equals Untransmittable (U = U) communicates that people living with HIV (PLHIV) who are on antiretroviral therapy (ART) will not transmit HIV to their sexual partners. We describe awareness of U = U among sexual and gender minorities (SGM) living in Brazil, Mexico, and Peru by self-reported HIV status (PLHIV, negative, unknown) during 2021 using an online survey. We estimated two models using Poisson regression for each population group: Model A including socio-demographic factors (country, gender, age, race, education, and income), and then Model B including taking ART (for PLHIV) or risk behavior, ever-taking PrEP, and HIV risk perception (for HIV-negative or of unknown HIV status). A total of 21,590 respondents were included (Brazil: 61%, Mexico: 30%, Peru: 9%). Among HIV-negative (74%) and unknown status (12%), 13% ever used PrEP. Among PLHIV (13%), 93% reported current use of ART. Awareness of U = U was 89% in both Brazil and Mexico, which was higher than in Peru 64%. Awareness of U = U was higher among PLHIV (96%) than HIV-negative (88%) and HIV-unknown (70%). In multivariate models, PLHIV with lower education were less aware of U = U, while those taking ART were more aware. Among HIV-negative, non-cisgender, lower income, and those with lower education had lower awareness of U = U, while individuals ever using PrEP had higher awareness. In conclusion, awareness of U = U varied by HIV status, socio-demographic characteristics, and HIV risk behavior. The concept of U = U should be disseminated through educational strategies and include a focus on SGM to combat HIV stigma.

RESUMEN: Indetectable = Intransmisible (I = I) comunica que las personas que viven con VIH (PVVIH) y reciben tratamiento antirretroviral (TAR) no transmitirán el VIH a sus parejas sexuales. En este estudio, describimos la concienciación sobre I = I entre las minorías sexuales y de género (MSG) de Brasil, México y Perú según el estado de VIH autoreportado (PVVIH, negativo, desconocido) durante 2021 utilizando una encuesta en línea. Se estimaron dos modelos mediante regresión de Poisson para cada grupo: Modelo A, que incluyó factores sociodemográficos (país, sexo, edad, raza, educación e ingresos) y Modelo B, que incluyó recibir TAR (para PVVIH) o comportamiento de riesgo, uso de PrEP y percepción de riesgo (para VIH negativo o desconocido). Se incluyó 21,590 encuestados (Brasil: 61%, México: 30%, Perú: 9%). Entre aquellos negativos para VIH (74%) y con estado desconocido (12%), el 13% utilizó alguna vez PrEP. Entre las PVVIH (13%), el 93% reportó recibir actualmente TAR. La concienciación de I = I fue del 89% tanto en Brasil como en México, superior al 64% de Perú. La concienciación de I = I fue mayor entre PVVIH (96%) que entre los VIH-negativos (88%) y los VIH-desconocidos (70%). En los modelos multivariados, las PVVIH con menor educación eran menos conscientes de I = I, mientras que los que tomaban TAR eran más conscientes. Entre los VIH-negativos, las personas no cisgéneros, con menores ingresos y con menor educación eran menos consciente de I = I, mientras que los que tenían experiencia usando PrEP eran más conscientes. En conclusión, la concienciación sobre I = I varió según el estado serológico de VIH, las características sociodemográficas y el comportamiento de riesgo. El concepto de I = I debe difundirse a través de estrategias educativas, incluyendo un enfoque en MSG para combatir el estigma del VIH.

Spatio-temporal dynamics of phytoplankton community in a well-mixed temperate estuary (Sado Estuary, Portugal).

Estuaries are highly productive ecosystems, which are strongly affected by several anthropogenic pressures. Phytoplankton is a key element for assessing the ecological quality status in these transitional waters. Moreover, understanding physico-chemical and biological drivers is crucial to disentangle their effect on the structure of phytoplankton community. The present work aims to study the effect of the main physico-chemical drivers on the phytoplankton community structure and dynamics in a temperate well-mixed estuary (Sado Estuary). Four sampling stations were analyzed monthly in three regions of the estuary, from 2018 to 2019. Surface water samples were collected to analyze the phytoplankton community and several concomitant physico-chemical parameters. Temperature, turbidity, salinity, and nutrients availability were the drivers that best explained the spatio-temporal patterns observed in the phytoplankton community. The upper estuary was characterized by higher phytoplankton cell abundances and biomass. Three phytoplankton groups stood out in the characterization of the estuarine assemblages: diatoms, cryptophytes, and dinoflagellates. Diatoms were the dominant group most of the year, being dominated by small cell species (single and chain-forming) upstream, and by larger chain-forming species downstream. Cryptophytes had a high contribution to the community in the inner regions of the estuary, while dinoflagellates contributed more for the community composition downstream, where high abundances of harmful algal species were sporadically found. Previous studies on the phytoplankton community dynamics in this estuary are limited to the 1990s. Thus, the present study provides insight into changes in the dominant phytoplankton groups of the Sado Estuary in the last 25 years, namely an increase in cryptophytes over diatoms in the inner estuarine regions, and an increase in dinoflagellates near the estuary mouth.

Evaluating the menopausal transition with the STRAW + 10 in a Brazilian cohort of women with HIV, 2015-2016.

BACKGROUND: Menopausal transition is a physiological process encompassing hormonal and body changes that impact women's health and life quality. This period may be characterized by the Stages of Reproductive Aging Workshop (STRAW + 10) criteria using menstrual patterns. Use of the STRAW + 10 is uncertain in HIV infection. We aimed to characterize menopausal transition in women with HIV (WWH) using the STRAW + 10 criteria, hormonal measures and menopause symptoms. METHODS: We performed a cross-sectional study, nested to the HIV-Infected Women's Cohort, in Rio de Janeiro, Brazil. Eligible women included those aged 30 years or older, without clinical or surgical menopause, hormonal contraception, replacement therapy and ovarian disorders. We conducted face-to-face interviews and collected blood samples for follicle stimulating hormone (FSH) and estradiol measures. RESULTS: We enrolled 328 WWH (28.3% of women in the cohort). The distribution of age, hormonal levels and reported symptoms per each STRAW + 10 stage was consistent with the expected distribution in the menopausal transition. Age and FSH significantly increased and estradiol decreased from stage -2 (7 + days of menstrual delay) to stage +2 (8 + years of amenorrhea). CONCLUSIONS: The present results support use of the STRAW + 10 to characterize the menopausal transition of WWH with good clinical and immunological control.

Diagnostic value of serological biomarkers for detection of non-alcoholic fatty liver disease (NAFLD) and/or advanced liver fibrosis in people living with HIV.

OBJECTIVES: We aimed to evaluate the accuracy of serological biomarkers for non-alcoholic fatty liver disease (NAFLD) and advanced fibrosis (METAVIR-F3F4) in HIV mono-infected individuals. METHODS: In all, 674 participants from the PROSPEC-HIV study (NCT02542020), who had blood sample tests and transient elastography (TE) performed on the same day, were eligible. Exclusion criteria were viral hepatitis co-infection (n = 90), abusive alcohol intake (n = 61), missing data (n = 47) or unreliable TE (n = 39). NAFLD was defined by controlled attenuation parameter ≥ 248 dB/m and advanced fibrosis by liver stiffness measurement ≥ 8.7 kPa with M probe or ≥ 7.2 kPa with XL probe. Biomarkers for NAFLD [Steato-ELSA, Fatty Liver Index (FLI), Hepatic Steatosis Index (HSI), NAFLD-Liver Fat Score (NAFLD-LFS)] and fibrosis [Fibrosis-4 score (FIB-4), Aspartate-to-Platelet Ratio Index (APRI) and NAFLD Fibrosis Score (NFS)] were calculated. RESULTS: A total of 437 patients [57% female, age = 44 (interquartile range: 35-52) years, body mass index (BMI) = 26.1 (23.4-29.3) kg/m2 , CD4 = 660 (427-901) cells/µL] were included. The prevalence [95% confidence interval (CI)] of NAFLD and advanced fibrosis were 38.2% (33.8-42.9) and 10.5% (8.0-13.8), respectively. The areas (95% CI) under the receiver operator curve (AUROCs) for diagnosis of NAFLD were 0.854 (0.818-0.889), 0.840 (0.804-0.877), 0.805 (0.762-0.847) and 0.793 (0.750-0.836) for Steato-ELSA, FLI, HSI and NAFLD-LFS (P < 0.001), respectively. All tests yielded satisfactory sensitivities, specificities and negative predictive values (NPVs). The AUROCs (95% CI) for diagnosis of advanced fibrosis were 0.736 (0.659-0.814), 0.700 (0.614-0.7851) and 0.795 (0.726-0.864) for FIB-4, APRI and NFS (P = 0.077), respectively. These tests yielded high specificities and negative predictive values (NPVs) > 90%. CONCLUSION: Biomarkers for NAFLD had a good accuracy and those for fibrosis had high specificities and NPVs. These tests should be integrated to HIV care to detect NAFLD and to exclude advanced liver fibrosis.

HIV-related tuberculosis: mortality risk in persons without vs. with culture-confirmed disease.

BACKGROUND: Tuberculosis (TB) diagnosis in human immunodeficiency virus (HIV) positive persons is difficult, particularly in resource-limited settings. The relationship between TB culture status and mortality in HIV-positive persons treated for TB is unclear. METHODS: We evaluated HIV-positive adults treated for TB at or after their first HIV clinic visit in Argentina, Brazil, Chile, Honduras, Mexico or Peru from 2000 to 2015. Anti-tuberculosis treatment included 2 months of isoniazid, rifampicin (RMP)/rifabutin (RBT), pyrazinamide ± ethambutol, followed by continuation phase treatment with isoniazid + RMP/RBT. RESULTS: Of 759 TB-HIV patients, 238 (31%) were culture-negative, 228 (30%) had unknown culture status or did not undergo culture and 293 (39%) were culture-positive. The median CD4 at TB diagnosis was 96 (interquartile range 40-228); 636 (84%) received concurrent antiretroviral therapy (ART) and anti-tuberculosis treatment. There were 123 (16%) deaths: 90/466 (19%) with TB culture-negative, unknown or not performed vs. 33/293 (11%) who were TB culture-positive (P = 0.005). In Kaplan-Meier analysis, mortality in TB patients without culture-confirmed disease was higher (P = 0.002). In a Cox model adjusted for age, sex, CD4, ART timing, disease site and stratified by study site, mortality in persons without culture-confirmed TB was not significantly increased compared to those with culture-positive TB (hazard ratio 1.39, 95%CI 0.89-2.16, P = 0.15). CONCLUSION: Most HIV-positive patients treated for TB did not have culture-confirmed TB, and mortality tended to be higher in patients without culture-confirmed disease, although the association was not statistically different after adjusting for other variables. Accurate TB diagnosis in HIV-positive persons is crucial.

Accuracy of quick sequential organ failure assessment score to predict mortality in hospitalized patients with suspected infection in an HIV/AIDS reference centre in Rio de Janeiro, Brazil.

OBJECTIVES: To compare the discriminatory capacity of the quick sequential organ failure assessment (qSOFA) vs. the systemic inflammatory response syndrome (SIRS) score for predicting 30-day mortality and intensive care unit (ICU) admission in patients with suspicion of infection at an HIV reference centre. METHODS: We performed a prospective cohort study including consecutive adult patients who had suspected infection and who were subsequently admitted to the medical ward. Variables related to qSOFA and SIRS were measured at admission. The performance (area under the receiver operating curve, AUROC) of qSOFA (score ≥2) and SIRS (≥2 criteria) as a predictor of 30-day mortality and ICU admission was evaluated. RESULTS: One hundred seventy-three patients (mean ± standard deviation age, 42.6 ± 12.4 years) were included in the analysis; 107 (61.8%) were male, and 111 (64.2%) were HIV positive. Respiratory and gastrointestinal infections occurred in 49 (28.3%) and 23 (13.3%), respectively. The 30-day mortality rate was 9 (5.2%) of 173. The prognostic performance of qSOFA was similar compared to SIRS, with an AUROC of 0.68 (95% confidence interval, 0.55-0.81) and 0.69 (95% confidence interval, 0.53-0.86) (p 0.96). Twenty patients (11%) were admitted to the ICU; qSOFA and SIRS had a similar discriminatory capacity for ICU admission (AUROC 0.63 (95% confidence interval, 0.51-0.75) and 0.63 (95% confidence interval, 0.50-0.76)), respectively). CONCLUSIONS: We found a poor prognostic accuracy of the qSOFA to predict 30-day mortality in hospitalized patients suspected of infection in a setting with a high burden of HIV infection.

Tuberculosis is associated with non-tuberculosis-related deaths among HIV/AIDS patients in Rio de Janeiro.

SETTING: Human immunodeficiency virus (HIV) infected patients followed in a large cohort in Rio de Janeiro, Brazil. OBJECTIVE: To evaluate the association of tuberculosis (TB) and other covariables with non-TB-related (NTR) causes of death (CODs). DESIGN: Patients aged >18 years were followed from 1997 to 2009, until death or 31 December 2009, whichever was earlier. CODs were ascertained using a standardised algorithm. TB diagnosis and prophylaxis followed Brazilian guidelines. Poisson models were used to calculate adjusted rate ratios (aRRs). RESULTS: Of 2887 patients included in the study, 761 had TB (26.4%). NTR death rates were twice as high among patients with TB (4/100 vs. 2.09/100 patient-years). TB was associated with NTR deaths (aRR 1.4, 95%CI 1.05-1.86, P = 0.01). Highly active antiretroviral treatment (HAART) was protective against NTR (aRR 0.46, 95%CI 0.34-0.61, P < 0.001). Among patients who had never had active TB, prophylaxis was also protective against NTR (aRR 0.45, P = 0.04). The CD4 cell count increase was very modest for both TB and NTR CODs compared to those who did not die (0 vs. 249 cells, P < 0.001). CONCLUSIONS: TB was significantly associated with increased NTR CODs, indicating rapid progression of disease and increased long-term risk of mortality, probably related to persistent immunodeficiency or incomplete immune recovery. Our results confirm the benefits of HAART and TB prophylaxis.

Association of the HLA-B*52 allele with non-progression to AIDS in Brazilian HIV-1-infected individuals.

Several human leukocyte antigen (HLA) class I alleles are associated with the susceptibility to human immunodeficiency virus-1 (HIV-1) infection and/or AIDS progression. Of these, the HLA-B alleles are considered the strongest genetic determinant of disease outcome. We evaluated the influence of the HLA-B alleles on AIDS progression among HIV-1-positive individuals from Rio de Janeiro, Brazil, who were categorized as rapid progressors (RPs), typical progressors (TPs) or long-term non-progressors (LTNPs). In this study, significant differences in HLA-B allele frequencies were observed among the three progression groups for the B*48, B*49 and B*52 alleles. After controlling for other factors associated with AIDS progression, the presence of the B*52 allele was shown to be a significant protective factor (hazard ratio (HR) 0.49 (95% confidence interval (CI) 0.27-0.90) P<0.03). Although no direct association was observed between the presence of the B*27 or B*57 allele and the LTNP profile compared with the TP or RP groups, the adjusted model confirmed that these alleles are protective factors against AIDS progression (HR 0.62 (95% CI 0.38-0.99) P<0.05), as previously described. These data corroborate the existence of significant differences in HLA-B allele frequencies among the distinct AIDS progression profiles and further elucidate the role of HLA alleles in the outcome of HIV infections in diverse populations.

Screening for pulmonary tuberculosis in HIV-infected individuals: AIDS Clinical Trials Group Protocol A5253.

BACKGROUND: Improved tuberculosis (TB) screening is urgently needed for human immunodeficiency virus (HIV) infected patients. METHODS: An observational, multi-country, cross-sectional study of HIV-infected patients to compare a standardized diagnostic evaluation (SDE) for TB with standard of care (SOC). SOC evaluations included TB symptom review (current cough, fever, night sweats and/or weight loss), sputum Ziehl-Neelsen staining and chest radiography. SDE screening added extended clinical signs and symptoms and fluorescent microscopy (FM). All participants underwent all evaluations. Mycobacterium tuberculosis on sputum culture was the primary outcome. RESULTS: A total of 801 participants were enrolled from Botswana, Malawi, South Africa, Zimbabwe, India, Peru and Brazil. The median age was 33 years; 37% were male, and median CD4 count was 275 cells/mm(3). Thirty-one participants (4%) had a positive culture on Löwenstein-Jensen media and 54 (8%) on MGIT. All but one positive culture came from sub-Saharan Africa, where the prevalence of TB was 54/445 (12%). SOC screening had 54% sensitivity (95%CI 40-67) and 76% specificity (95%CI 72-80). Positive and negative predictive values were respectively 24% and 92%. No elements of the SDE improved the predictive values of SOC. CONCLUSIONS: Symptom-based screening with smear microscopy was insufficiently sensitive. More sensitive diagnostic testing is required for HIV-infected patients.

Seroprevalence of HPV vaccine types 6, 11, 16 and 18 in HIV-infected and uninfected women from Brazil.

BACKGROUND: Information on vaccine-type HPV seroprevalence is essential for vaccine strategies; however, limited data are available on past exposure to HPV-quadrivalent vaccine types in HIV-infected woman in Brazil. OBJECTIVES: To assess the seroprevalence for HPV types 6, 11, 16 and 18 in HIV-infected and uninfected women, from Rio de Janeiro, Brazil and to investigate potential associations with age and pregnancy status. STUDY-DESIGN: 1100-sera were tested by virus-like particle (VLPs)-based ELISA for antibodies to HPV types 16, 18, 6 and 11. Statistical analysis was carried out by STATA/SE 10.1 and comparisons among HIV-infected and HIV-uninfected women were assessed by Poisson regression models with robust variance. RESULTS: HPV-6, 11, 16 and 18 seroprevalence was significantly higher among HIV-positive women (29.9%, 8.5%, 56.2% and 38.0%, respectively) compared to HIV-negative women (10.9%, 3.5%, 30.8% and 21.7%, respectively), when adjusted by age and pregnancy status. Overall, 69.4% of HIV-infected and 41.5% of HIV-uninfected women tested positive for any HPV quadrivalent vaccine type. However 4.7% and 1.1%, respectively, tested positive for all HPV vaccine type. In HIV-uninfected women who were pregnant, we found a higher HPV-11 seroprevalence (8.5% vs. 1.5%; P < 0.001) and a lower HPV 16 seroprevalence (22.6% vs. 34.2%; P = 0.010) compared to not pregnant women. HIV-uninfected women, aged 40 or more years old had a higher HPV 16 seroprevalence compared to women aged less than 40 years old. CONCLUSIONS: We did not observe a strong association between age and positive HPV antibodies nor an association between pregnancy and HPV seroprevalence. HPV seroprevalence was significantly higher among HIV-infected women compared to HIV negative women. In both populations the seroprevalence to all four HPV vaccine types was low suggesting that women may potentially benefit from the HPV vaccines.

Fruit flies (diptera, tephritidae) in municipalities with a risk mitigation system for anastrepha grandis macquart / Moscas-das-frutas (Diptera, Tephritidae) em municípios com sistema de mitigação de risco para Anastrepha Grandis Macquart

The objective of this study was verify the presence of A. grandis and identify other fruit-fly species collected in MacPhail traps, installed in areas of Cucurbitaceae under a risk mitigation system for Anastrepha grandis Macquart in the Vale do São Patrício Region, state of Goiás, Brazil, from November 2004 to October 2009. A total of 812 specimens of Anastrepha were captured, of which 639 were males (78.7%) and 173 were females (21.3%). Fourteen species of Anastrepha were identified occurring in all seasons of the year. A. dissimilis Stone, A. quiinae Lima and A. pickeli Lima were recorded for the first time in the state of Goiás, and A. grandis and was recorded for the first time, with a low prevalence, in the municipalities of Jaraguá and Uruana, which belong to the risk mitigation system area, indicating good conditions for maintaining an area of low prevalence status. A. manihoti Lima (34.10%) was the most frequent species in the region, followed by A. obliqua (Macquart) (19.65%) and A. pickeli Lima (13.87%).

O objetivo do estudo foi verificar a presença de Anastrepha grandis e identificar demais espécies de moscas-das-frutas coletadas em armadilhas modelo MacPhail instaladas em áreas de cucurbitáceas sob Sistema de Mitigação de Risco (SMR) para A. grandis na região Vale do São Patrício, GO, de novembro de 2004 a outubro de 2009. Um total de 812 espécimes de Anastrepha foram capturadas, sendo 639 machos (78,7%) e 173 fêmeas (21,3%). Destas foram identificadas 14 espécies de Anastrepha, ocorrentes em todas as estações do ano. A. dissimilis Stone, A. quiinae Lima e A. pickeli Lima foram registradas pela primeira vez em Goiás e primeiro registro de A grandis, com baixa prevalência, nos municípios de Jaraguá e Uruana, constituintes da área de SMR, indicando ótimas condições para manutenção de área de baixa prevalência. A. manihoti Lima (34,10%) foi a espécie mais frequente na região, seguidade A. obliqua (Macquart) (19,65%) e A. pickeli (13,87%).

Cervical cytological abnormalities and factors associated with high-grade squamous intraepithelial lesions among HIV-infected women from Rio de Janeiro, Brazil.

Although cervical cancer remains a major public health problem in Brazil, knowledge of cervical cytological abnormalities among HIV-infected women remains scarce. At baseline evaluation of a cohort followed in Rio de Janeiro, Brazil, 703 HIV-infected women underwent cytology-based cervical cancer screening and human papillomavirus (HPV) DNA testing. Poisson regression analysis was used to evaluate the association of factors with the presence of high-grade squamous intraepithelial lesions (HSIL). Cervical cytology was abnormal in 24.3% of the women; 4.1% had HSIL. Beyond HPV infection, factors independently associated with the presence of HSIL was age (≥25 and ≤40 years, prevalence ratio [PR] 2.60, 95% confidence interval [CI] 1.11-6.10), and more than three pregnancies was protective (PR 0.33, 95% CI 0.11-0.94). High coverage of cervical cancer screening is warranted to prevent morbidity and mortality from cervical cancer in this population.

Analysis of serious non-AIDS events among HIV-infected adults at Latin American sites.

OBJECTIVE: Acquired immune deficiency appears to be associated with serious non-AIDS (SNA)-defining conditions such as cardiovascular disease, liver and renal insufficiency and non-AIDS-related malignancies. We analysed the incidence of, and factors associated with, several SNA events in the LATINA retrospective cohort. MATERIALS AND METHODS: Cases of SNA events were recorded among cohort patients. Three controls were selected for each case from cohort members at risk. Conditional logistic models were fitted to estimate the effect of traditional risk factors as well as HIV-associated factors on non-AIDS-defining conditions. RESULTS: Among 6007 patients in follow-up, 130 had an SNA event (0.86 events/100 person-years of follow-up) and were defined as cases (40 with cardiovascular events, 54 with serious liver failure, 35 with non-AIDS-defining malignancies and two with renal insufficiency). Risk factors such as diabetes, hepatitis B and C virus coinfections and alcohol abuse showed an association with events, as expected. The last recorded CD4 T-cell count prior to index date (P = 0.0056, with an average difference of more than 100 cells/µL) and area under the CD4 cell curve in the year previous to index date (P = 0.0081) were significantly lower in cases than in controls. CD4 cell count at index date was significantly associated with the outcome after adjusting for risk factors. CONCLUSIONS: The incidence and type of SNA events found in this Latin American cohort are similar to those reported in other regions. We found a significant association between immune deficiency and the risk of SNA events, even in patients under antiretroviral treatment.

Efeito fisiológico do inseticida thiamethoxam na cultura da cana-de-açúcar / Physiological effect of the insecticide thiamethoxam on sugarcane

Com a finalidade de avaliar o efeito fisiológico de thiamethoxam no desenvolvimento inicial de plantas de cana-de-açúcar, foram realizados dois experimentos. O primeiro conduzido em caixas plásticas do tipo gerbox (3,5 x 11 x 11 cm) contendo substrato, aplicou-se thiamethoxam em toletes de cana-de-açúcar, nas doses: 0, 100, 150 e 200 g de ingrediente ativo (i.a.).ha-1. O segundo experimento foi realizado em tubos de PVC (0,2 x 1,20 m), preenchido com solo, utilizaram-se seis doses de thiamethoxam (0, 50, 100, 150, 200 e 250 g i.a.ha-1) em mudas de duas variedades (RB867515 e SP80-1816). Avaliou-se a parte área e o sistema radicular das plantas aos 30 dias após a aplicação do inseticida, no primeiro experimento e aos 130 dias no segundo. Observou-se que no primeiro experimento as características altura, diâmetro e massa seca da parte área não foram alterados em razão da aplicação do inseticida nos toletes de cana-de-açúcar, porém, nos tratamentos com thiamethoxam houve um incremento na massa seca das raízes de até 3,7 vezes mais. No segundo experimento, thiamethoxam proporcionou aumento no diâmetro das plantas e incremento na massa seca das raízes da variedade RB867515 de até 72,69%. No entanto, o comprimento do sistema radicular e a massa seca da parte aérea não foram alterados pela aplicação do inseticida nas mudas.

With the purpose to evaluate the physiological effect of thiamethoxam on the initial development of sugarcane, two experiments were carried out. In the first, carried out in Gerbox-type plastic boxes (3.5 x 11 x 11 cm) containing substrate, thiamethoxam was applied on sugarcane cuttings at the doses of 0, 100, 150 and 200 g of active ingredient per hectare (a.i.ha-1). The second experiment was carried in PVC pipes (0.2 x 1.20 m), filled with soil. Six doses of thiamethoxam (0, 50, 100, 150, 200 and 250 g a.i.ha -1) were used on two cultivars (RB867515 and SP80-1816).Roots and shoots were evaluated 30 days after the insecticide application in the first experiment and after 130 days in the second one. In the first experiment it was observed that the height characteristics, diameter and dry mass of shoots did not change through the use of the insecticide on sugarcane cuttings, however, in the treatments with thiamethoxam there was an increase on roots dry mass up to 3.7 times more. In the second experiment, thiamethoxam increased the diameter of shoots and the root dry mass of RB867515 cultivar up 72.69%. However, the length of the root system and the shoot dry mass were not changed by insecticide application in seedlings.

Trypanosoma cruzi: immunoglobulin isotype profiles during the acute phase of canine experimental infection with metacyclic or blood trypomastigotes.

A detailed investigation has been carried out about the serological profiles of groups of dogs experimentally infected with metacyclic (MT) or blood (BT) trypomastigotes of Berenice-78 Trypanosoma cruzi strain. Peripheral blood was collected from infected dogs and uninfected controls, weekly during 35 days following the acute phase of infection, and immunoglobulin profiles were determined by ELISA. Dogs infected with BT exhibited unaltered levels of IgG2, increases in IgM, IgE, IgA, IgG and IgG1. In contrast, dogs infected with MT presented unaltered levels of IgE and IgG1 and an increase in IgM, IgA, IgG and IgG2 levels. Compared with the MT group, animals infected with BT showed significant increases in IgM on days 7, 14 and 28, in IgA on days 7, 14 and 21, in IgE on days 7 and 14, in IgG on days 14 and 28, and in IgG1 on days 7, 14 and 21. Parasitemia levels of the infected animals were measured over the same time period. No correlations were found between the immunoglobulin profiles and the parasitemia levels. The results demonstrated that the inoculum source (BT or MT) influence the immunoglobulin isotype profile that may drive distinct outcome of acute canine Chagas disease.

Impact of dual infections on chemotherapeutic efficacy in BALB/c mice infected with major genotypes of Trypanosoma cruzi.

The aim of this work was to investigate the impact of dual infections with stocks of Trypanosoma cruzi major genotypes on benznidazole (BZ) treatment efficacy. For this purpose, T. cruzi stocks representative of the genetic T. cruzi lineages, displaying different susceptibilities to BZ, belonging to the major T. cruzi genotypes broadly dispersed in North and South America and important in Chagas' disease epidemiology were used. Therapeutic efficacy was observed in 27.8% of the animals treated. Following BZ susceptibility classification, significant differences were observed in dual infections on the major genotype level, demonstrating that combinations of genotypes 19+39 and genotypes 19+32 led to a shift in the expected BZ susceptibility profile toward the resistance pattern. Analysis on the T. cruzi stock level demonstrated that 9 out of 24 dual infections shifted the expected BZ susceptibility profile compared with the respective single infections, including shifts toward lower and higher BZ susceptibilities. Microsatellite identification was able to identify a mixture of T. cruzi stocks in 7.7% of the T. cruzi isolates from infected and untreated mice (6.9%) and infected and treated but not cured mice (9.0%), revealing in some mixtures of BZ-susceptible and -resistant stocks that the T. cruzi stock identified after BZ treatment was previously susceptible in single infections. Considering the clonal structure and evolution of T. cruzi, an unexpected result was the identification of parasite subpopulations with distinct microsatellite alleles in relation to the original stocks observed in 12.2% of the isolates. Taken together, the data suggest that mixed infections, already verified in nature, may have an important impact on the efficacy of chemotherapy.

Evaluation of the consistency of refills for antiretroviral medications in two hospitals in the state of Rio de Janeiro, Brazil.

We conducted a retrospective cohort study using pharmacy records to assess the frequency of delay in picking up antiretroviral (ARV) medication refills from the pharmacy and to identify determinants of delay among HIV-infected patients at two Brazilian hospitals. We selected patients who were on ARV therapy before January 2001 at Nova Iguaçu Hospital (NIPRH) (N = 265) and Evandro Chagas (N=424) Clinical Research Institute. We abstracted medical records and pharmacy data using standardised forms and analysed potential associations between delay in refilling medications and patients' demographic characteristics, type of ARV drug regimen and evolution of HIV disease. Sixty-nine patients (26%) had delays in medication refills >1 month at least once in 2001 at NIPRH compared with 140 (33%) patients at IPEC (p=0.052). No factor was found to be associated with having a delay in medication refill >1 month at NIPRH. At IPEC, delays in medication refill >1 month were associated with a median CD4+ T cell count <200/mm(3) versus >500/mm(3) (adjusted odds ratio (AOR) = 3.8; 95% confidence interval (CI) =1.6-8.9) and with dual protease inhibitor-based ARV regimens versus other regimens (AOR = 4.3; 95% CI = 1.9-9.4). In conclusion, rates of delay in medication refills were similar to rates of adherence to ARV therapy found in other studies in Brazil, suggesting that delay in medication refills could be used as a surrogate for adherence. Analysing ARV medication refills can complement self-reported information on adherence.

Trypanosoma cruzi: Impact of dual-clone infections on parasite biological properties in BALB/c mice.

Herein, we have analyzed major biological properties following dual-clone Trypanosoma cruzi infections in BALB/c mice. Eight T. cruzi clonal stocks, two of each principal genotype, including genotype 19 and 20 (T. cruzi I), hybrid genotype 39 (T. cruzi) and 32 (T. cruzi II) were combined into 24 different dual-clone infections. Special attention was given to characterize biological parameters assayed including: prepatent period, patent period, maximum of parasitemia, day of maximum parasitemia, area under the parasitemia curve, infectivity, mortality, and hemoculture positivity. Our findings clearly demonstrated that features resultant of dual-clone infections of T. cruzi clonal stocks did not display either the characteristics of the corresponding monoclonal infections or the theoretical mixture based on the respective monoclonal infections. Significant changes in the expected values were observed in 4.2-79.2% of the mixtures considering the eight biological parameters studied. A lower frequency of significant differences was found for mixtures composed by phylogenetically distant clonal stocks. Altogether, our data support our hypothesis that mixed T. cruzi infections have a great impact on the biological properties of the parasite in the host and re-emphasizes the importance of considering the possible occurrence of natural mixed infections in humans and their consequences on the biological aspects of ongoing Chagas' disease.

Further genetic characterization of the two Trypanosoma cruzi Berenice strains (Be-62 and Be-78) isolated from the first human case of Chagas disease (Chagas, 1909).

We describe here an extension of a previous genetic characterization of Trypanosoma cruzi strains (Be-62 and Be-78) isolated from the patient Berenice, the first human case of Chagas disease [Chagas, C., 1909. Nova Tripanomíase humana. Estudos sobre morfologia e o ciclo evolutivo do Schizotrypanum cruzi, n. gen., n. sp., agente etiolójico da nova entidade morbida do homem. Mem. Inst. Oswaldo Cruz 1, 159-218]. We wanted to verify the composition of T. cruzi populations originated from these two isolates. In the present work, 22 enzymatic loci (MLEE), nine RAPD primers and 7 microsatellite loci were analyzed. Clones from both strains were also characterized to verify whether these strains are mono or polyclonal. Be-62 and Be-78 strains were different in 3 out of 22 enzymatic systems, in 3 out of 9 RAPD primers tested and in all microsatellite loci investigated. However, our data suggests that both strains are phylogenetically closely related, belonging to genetic group 32 from Tibayrenc and Ayala [Tibayrenc, M., Ayala, F.J., 1988. Isoenzime variability in Trypanosoma cruzi, the agent of Chagas' disease: genetical, taxonomical, and epidemiological significance. Evolution 42, 277-292], equivalent to zymodeme 2 and T. cruzi II major lineage which, in Brazil, comprises parasites from the domestic cycle of the disease. Microsatellite analyses showed differences between the parental strains but suggested that both populations are monoclonal since each strain and their respective clones showed the same amplification products.

Influence of the long-term Trypanosoma cruzi infection in vertebrate host on the genetic and biological diversity of the parasite.

The influence of the long-term Trypanosoma cruzi infection in vertebrate host on the biological and genetic properties of the parasite was evaluated. Four T. cruzi isolates obtained from different chronic chagasic dogs infected with Berenice-78 T. cruzi strain during 2 and 7 years were comparatively analyzed. The long-term T. cruzi infection has led to alterations in parasitemia, virulence and pathogenicity of Be-78 strain for mice. These biological parameters varied from low to high in realation to the parental strain. Randomly amplified polymorphic DNA and isoenzyme profiles detected two distinct genetic groups of parasites. The first group included the parental strain and two T. cruzi isolates, and the second group the two other isolates. Interestingly, the isolates of the second group showed a reversibility of the genetic profile to the parental strain after 25 passages in mice. No correlation between the genetic groups and biological properties of the isolates was observed. Our findings confirmed the population heterogeneity of the Be-78 strain, and showed how differently it responds to the long-term infection in the same vertebrate hosts.