The purpose of this study was to determine the prevalence, associated risk factors and genotype of Giardia duodenalis infection in children attending public daycare centers in the city of Araguari, state of Minas Gerais, Brazil. Fecal samples were collected from 245 children aged 0-5 years, and questionnaires were asked about sociodemographic and hygiene-related characteristics. At the daycare centers where children tested positive, fecal samples were collected from the staff handling food, and from family members and domestic animals. Positive samples were analyzed at the dehydrogenase glutamate (gdh) locus to determine the genotype. The prevalence of G. duodenalis was 51.8%, and drinking unfiltered and unboiled water (OR 2.12, CI 1.26-3.69, p<0.001) and washing hands only with water (OR 2.14, CI 1.19-4.04, p<0.001) were related risk factors. No association was found between test-positive children and their family members, domestic animals and food handlers. An analysis of the sequences of 30 samples revealed that they all belonged to genotype B.

Giardia duodenalis is a parasite of several mammalian species, including humans, distributed worldwide. This research aimed to identify the molecular assemblages/sub-assemblages of G. duodenalis and to determine the intra-assemblage genetic variation of the different genes of assemblages A and B in pre-school children in the cities of Araguari and Uberlândia, Minas Gerais, Brazil. The molecular characterization followed β-giardin (bg), glutamate dehydrogenase (gdh) and triose phosphate isomerase (tpi) protocols. Of 226 stool samples, G. duodenalis cysts were found in 45 (19.9%). The tpi gene was amplified in 34 samples: 16 assemblage A, 14 B and four mixed samples A/B. The gdh gene was amplified in 32 samples, including 14 A, 16 B and two A/B. For the bg gene, 19 samples were sequenced: nine assemblage A, five B, three E, and two mixed, A/E and B/E. Animal-specific assemblage E were identified by bg, but were not confirmed for other genes. Twelve samples were characterized by full agreement of the three genes. Two new multilocus genotyping (MLGs) for assemblage A and two new MLGs for assemblage B were also described. These findings substantiate the importance of using more than one gene protocol since the sensitivity and genetic variability changes with the locus used. Access numbers: The GenBank access numbers for the nucleotide sequences reported in this article are: JQ794877–JQ794890, JX033113–JX033118

Integration of larvivorous fish and biolarvicides at low concentrations to control of mosquito larvae in field situations may result in a safer and more effective tool. However, the usefulness of integrated approach depends upon survival and ecological fitness of fish employed. Thus, the aim of this study was to examine the genotoxic effects of combining different sublethal concentrations of spinosad, a naturally occurring neurotoxic insecticide, with male adult poecilid larvivorous guppy (Poecilia reticulata) and platy (Xiphophorus maculatus) fish on Aedes larvae mosquitos. Both fish species have been used for biological control of Aedes larvae in Brazil. Sublethal spinosad exposures were predetermined based on CL_50-96hr. Nuclear abnormalities (NA) and micronucleus (MN) frequency in gill cells were measured after 14 d of exposure. Behavioral changes were monitored over 96 h. Although genotoxic effects were not markedly different from control, behavioral changes evaluated based upon the no-observable-effect concentration (NOEC) and lowest-observable-effect concentration (LOEC). Adverse effects were noted at concentrations of 12.6 mg/L (NOEC) and 25.3 mg/L (LOEC) spinosad. Therefore, these insecticide concentrations may be considered as being safe to these fish species and have important implications for integrated approach to control Aedes larvae using natural larvicides and larvivorous fish.

The polymerase chain reaction (PCR)-based methods for the diagnosis of malaria infection are expected to accurately identify submicroscopic parasite carriers. Although a significant number of PCR protocols have been described, few studies have addressed the performance of PCR amplification in cases of field samples with submicroscopic malaria infection. Here, the reproducibility of two well-established PCR protocols (nested-PCR and real-time PCR for the Plasmodium 18 small subunit rRNA gene) were evaluated in a panel of 34 blood field samples from individuals that are potential reservoirs of malaria infection, but were negative for malaria by optical microscopy. Regardless of the PCR protocol, a large variation between the PCR replicates was observed, leading to alternating positive and negative results in 38% (13 out of 34) of the samples. These findings were quite different from those obtained from the microscopy-positive patients or the unexposed individuals; the diagnosis of these individuals could be confirmed based on the high reproducibility and specificity of the PCR-based protocols. The limitation of PCR amplification was restricted to the field samples with very low levels of parasitaemia because titrations of the DNA templates were able to detect < 3 parasites/µL in the blood. In conclusion, conventional PCR protocols require careful interpretation in cases of submicroscopic malaria infection, as inconsistent and false-negative results can occur.

Association analysis between common mental disorders (CMD) and working conditions is necessary to achieve a better understanding of the reasons for physical and mental illness among teachers. In the present cross-sectional study we sought to establish the prevalence of CMD among teachers in public municipal elementary schools in Uberlândia, Minas Gerais, Brazil, and its correlation with sociodemographic, environmental and occupational aspects. A random sample of 330 teachers from 36 schools responded the General Health Questionnaire-12 and a structured questionnaire designed to investigate risk and protective factors for CMD. The collected data were first subjected to bivariate, then to multiple logistic regression analysis. The results indicate that the following characteristics were associated with CMD: female sex, permanent employment relationship, working double shifts, previous experience with school violence and use of sleep disorder drugs. We conclude that the mental health of teachers does not receive the proper attention and care even though it has direct impact on the teaching-learning cycle. Decreasing the rates of absenteeism, presenteeism, turnover, early retirement and sick leave reduces the government’s costs, while positive impacts extend to society at large.