A comparison of molecular markers to detect Lutzomyia longipalpis naturally infected with Leishmania (Leishmania) infantum

The aim of the present study was to detect natural infection by Leishmania (Leishmania) infantum in Lutzomyia longipalpis captured in Barcarena, state of Pará, Brazil, through the use of three primer sets. With this approach, it is unnecessary to previously dissect the sandfly specimens. DNA of 280 Lu. longipalpis female specimens were extracted from the whole insects. PCR primers for kinetoplast minicircle DNA (kDNA), the mini-exon gene and the small subunit ribosomal RNA (SSU-rRNA) gene of Leishmania were used, generating fragments of 400 bp, 780 bp and 603 bp, respectively. Infection by the parasite was found with the kDNA primer in 8.6% of the cases, with the mini-exon gene primer in 7.1% of the cases and with the SSU-rRNA gene primer in 5.3% of the cases. These data show the importance of polymerase chain reaction as a tool for investigating the molecular epidemiology of visceral leishmaniasis by estimating the risk of disease transmission in endemic areas, with the kDNA primer representing the most reliable marker for the parasite.

Leprosy: review of the epidemiological, clinical, and etiopathogenic aspects - Part 1

Leprosy is caused by Mycobacterium leprae and has been known since biblical times. It is still endemic in many regions of the world and a public health problem in Brazil. The prevalence rate in 2011 reached 1.54 cases per 10,000 inhabitants in Brazil. The mechanism of transmission of leprosy consists of prolonged close contact between susceptible and genetically predisposed individuals and untreated multibacillary patients. Transmission occurs through inhalation of bacilli present in upper airway secretion. The nasal mucosa is the main entry or exit route of M. leprae. The deeper understanding of the structural and biological characteristics of M. leprae, the sequencing of its genome, along with the advances in understanding the mechanisms of host immune response against the bacilli, dependent on genetic susceptibility, have contributed to the understanding of the pathogenesis, variations in the clinical characteristics, and progression of the disease. This article aims to update dermatologist on epidemiological, clinical, and etiopathogenic leprosy aspects.

Trypanosoma cruzi strains from triatomine collected in Bahia and Rio Grande do Sul, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distributional potential of the Triatoma brasiliensis species complex at present and under scenarios of future climate conditions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Healthcare-associated infections: challenges to public health in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise molecular de estirpes de Escherichia coli enteropatogênica (EPEC) isoladas de animais e humanos

Pós-graduação em Microbiologia Agropecuária - FCAV

The ant fauna of hospitals: advancements in public health and research priorities in Brazil

Ants inhabit several types of natural and urban habitats, where they successfully nest. In urban environments, the hospitals should be considered priority for studies, as ants pose risks to human health due to their pathogen carrying potential. We aimed at surveying the literature about studies on ants in hospital settings in Brazil in the past 20 years. We found 40 papers in 22 journals, the first one published in 1993. Among them, 26 papers assessed pathogenic microorganisms on ants. We recorded 59 ant species, being Tapinoma melanocephalum the most common. The Minas Gerais and Sao Paulo states had the largest number of published papers. Mato Grosso do Sul and Rio Grande do Sul showed the highest number of species. Exotic ant species were recorded in all states, except Goias. Considering the potential to carry microorganisms and the importance of thorough studies on the ecology of ant species, our results can support and guide further research in Brazil. (C) 2015 Sociedade Brasileira de Entomologia. Published by Elsevier Editora Ltda. All rights reserved.

Evaluation of the presence of microorganisms in solid-organ preservation solution

OBJECTIVE: To assess the presence of microorganism contamination in the preservation solution for transplant organs (kidney/pancreas). Method: Between August 2007 and March 2008, 136 samples of preservation solution were studied prior to graft implantation. Variables related to the donor and to the presence of microorganisms in the preservation solution of organs were evaluated, after which the contamination was evaluated in relation to the recipient culture variable. Univariate and multivariate statistical analyses were performed. RESULTS: The contamination rate of the preservation solution was 27.9%. Coagulase-negative Staphylococcus was the most frequently isolated microorganism. However, highly virulent agents, such as fungi and enterobacteria, were also isolated. In univariate analysis, the variable donor antibiotic use was significantly associated to the contamination of the preservation solution. on the other hand, multivariate analysis found statistical significance in donor antibiotic use and donor's infectious complications variables. CONCLUSIONS: In this study, 27.9% of the preservation solutions of transplant organs were contaminated. Infectious diseases and non-use of antibiotics by the donor were significantly related to the presence of microorganisms in organ preservation solutions. Contamination in organ preservation solutions was not associated with infection in the recipient.

Type of light in sand fly captures (Diptera:Psychodidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Development of a Model of Natural Infection with Mycobacterium bovis in White-Tailed Deer

The objective of this study was to develop a suitable experimental model of natural Mycobacterium bovis infection in white-tailed deer (Odocoileus virginianus), describe the distribution and character of tuberculous lesions, and to examine possible routes of disease transmission. In October 1997, 10 mature female white-tailed deer were inoculated by intratonsilar instillation of 2 3 103 (low dose) or 2 3 105 (high dose) colony forming units (CFU) of M. bovis. In January 1998, deer were euthanatized, examined, and tissues were collected 84 to 87 days post inoculation. Possible routes of disease transmission were evaluated by culture of nasal, oral, tonsilar, and rectal swabs at various times during the study. Gross and microscopic lesions consistent with tuberculosis were most commonly seen in medial retropharyngeal lymph nodes and lung in both dosage groups. Other tissues containing tuberculous lesions included tonsil, trachea, liver, and kidney as well as lateral retropharyngeal, mandibular, parotid, tracheobronchial, mediastinal, hepatic, mesenteric, superficial cervical, and iliac lymph nodes. Mycobacterium bovis was isolated from tonsilar swabs from 8 of 9 deer from both dosage groups at least once 14 to 87 days after inoculation. Mycobacterium bovis was isolated from oral swabs 63 and 80 days after inoculation from one of three deer in the low dose group and none of four deer in the high dose group. Similarly, M. bovis was isolated from nasal swabs 80 and 85 days after inoculation in one of three deer from the low dose group and 63 and 80 days after inoculation from two of four deer in the high dose group. Intratonsilar inoculation with M. bovis results in lesions similar to those seen in naturally infected white-tailed deer; therefore, it represents a suitable model of natural infection. These results also indicate that M. bovis persists in tonsilar crypts for prolonged periods and can be shed in saliva and nasal secretions. These infected fluids represent a likely route of disease transmission to other animals or humans.

Milk Containing Mycobacterium bovis as a Source of Infection for White-Tailed Deer Fawns (Odocoileus virginianus)

Setting:White-tailed deer represent the first wildlife reservoir of Mycobacterium bovis in the United States. The behavior of does with nursing fawns provides several potential mechanisms for disease transmission. Little information exists concerning transmission between doe and fawn, specifically transmammary transmission. Objective: Determine if fawns can become infected by ingestion of milk replacer containing M. bovis, thus simulating transmission from doe to fawn through contaminated milk. Design: Seventeen, 21-day-old white-tailed deer fawns were inoculated orally with 2x108 CFU (high dose, n=5), 2.5 x 105 to 2.5 x 106 CFU (medium dose, n=5), and 1x104 CFU (low dose, n=5) of M. bovis in milk replacer. Dosages were divided equally and fed daily over a 5-day period. Positive control fawns (n=2) received 1x105 CFU of M. bovis instilled in the tonsillar crypts. Fawns were euthanized and examined 35-115 days after inoculation and various tissues collected for bacteriologic and microscopic analysis. Results: All fawns in the tonsillar, high oral and medium oral dose groups developed generalized tuberculosis involving numerous organs and tissues by 35-84 days after inoculation. Three of five fawns in the low-dose oral group had tuberculous lesions in the mandibular lymph node, and one of five had lesions in the medial retropharyngeal lymph node when examined 115 days after inoculation. Conclusion: White-tailed deer fawns can become infected through oral exposure to M. bovis. Therefore, the potential exists for fawns to acquire M. bovis while nursing tuberculous does.

Deer Guards and Bump Gates for Excluding White-Tailed Deer From Fenced Resources

White-tailed deer (Odocoileus virginianus) causing damage is a reoccurring theme in the realm of wildlife damage management, especially regarding human safety, disease transmission, and agricultural losses. Fences often are the only reliable long-term nonlethal means of controlling deer damage. The efficacy of fences, however, relies on their weakest link: human-operated gates. Although not overly time-consuming, the act of closing a gate appears to be a burden to individuals, resulting in open-access to an otherwise protected resource. We examined the efficacy of 2 alternatives to traditional gates to evaluate their potential to be used for excluding or containing deer. We evaluated a commercially available kit for mechanically opening and closing gates and a modified deer guard that resembles a common cattle guard but incorporates bearing-mounted rollers as cross members. The gate kit proved effective in restricting deer access to bait throughout the study, but, in supplemental evaluations, we observed excessive rates of functional failure. Deer guards reduced deer entry into exclosures, but efficacy declined with time as deer walked and jumped across guards. With some refining, both guards and gates have potential to be useful components of an integrated biosecurity strategy.

Crop, Native Vegetation, and Biofuels: Response of White- Tailed Deer to Changing Management Priorities

The expansion of the cellulosic biofuels industry throughout the United States has broad-scale implications for wildlife management on public and private lands. Knowledge is limited on the effects of reverting agriculture to native grass, and vice versa, on size of home range and habitat use of white-tailed deer (Odocoileus virginianus). We followed 68 radio-collared female deer from 1991 through 2004 that were residents of DeSoto National Wildlife Refuge (DNWR) in eastern Nebraska, USA. The refuge was undergoing conversion of vegetation out of row-crop agriculture and into native grass, forest, and emergent aquatic vegetation. Habitat in DNWR consisted of 30% crop in 1991 but removing crops to establish native grass and wetland habitat at DNWR resulted in a 44% reduction in crops by 2004. A decrease in the amount of crops on DNWR contributed to a decline in mean size of annual home range from 400 ha in 1991 to 200 ha in 2005 but percentage of crops in home ranges increased from 21% to 29%. Mean overlap for individuals was 77% between consecutive annual home ranges across 8 years, regardless of crop availability. Conversion of crop to native habitat will not likely result in home range abandonment but may impact disease transmission by increasing rates of contact between deer social groups that occupy adjacent areas. Future research on condition indices or changes in population parameters (e.g., recruitment) could be incorporated into the study design to assess impacts of habitat conversion for biofuel production.

Livestock Protection Dogs for Deterring Deer From Cattle and Feed

Disease transmission between wildlife and livestock is a worldwide issue. Society needs better methods to prevent interspecies transmission to reduce disease risks. Producers have successfully used livestock protection dogs (LPDs) for thousands of years to reduce predation. We theorized that LPDs raised and bonded with cattle could be used to also reduce risk of bovine tuberculosis (Myobacterium bovis; TB) transmission between white-tailed deer (Odocoileus virginianus) and cattle by minimizing contact between the 2 species and use of cattle feed by deer. We evaluated 4 LPDs over 5 months, utilizing 2 data collection methods (direct observation and motion-activated video) on deer farms that supported higher densities than wild populations. Dogs were highly effective in preventing deer from using concentrated cattle feed (hay bales), likely the greatest risk factor of TB transmission on farms. Dogs also prevented deer from approaching cattle in core areas of pastures (near hay bales) and were very effective throughout pastures. Our research supports the theory that LPDs, specifically trained to remain with cattle, may be a practical tool to minimize potential for livestock to contract TB from infected deer in small-scale cattle operations. Where disease is present in deer, it may be possible to reduce the potential for disease transmission by employing LPDs.

A stochastic spatially structured epidemic model with diffusive processes

We developed a stochastic lattice model to describe the vector-borne disease (like yellow fever or dengue). The model is spatially structured and its dynamical rules take into account the diffusion of vectors. We consider a bipartite lattice, forming a sub-lattice of human and another occupied by mosquitoes. At each site of lattice we associate a stochastic variable that describes the occupation and the health state of a single individual (mosquito or human). The process of disease transmission in the human population follows a similar dynamic of the Susceptible-Infected-Recovered model (SIR), while the disease transmission in the mosquito population has an analogous dynamic of the Susceptible-Infected-Susceptible model (SIS) with mosquitos diffusion. The occurrence of an epidemic is directly related to the conditional probability of occurrence of infected mosquitoes (human) in the presence of susceptible human (mosquitoes) on neighborhood. The probability of diffusion of mosquitoes can facilitate the formation of pairs Susceptible-Infected enabling an increase in the size of the epidemic. Using an asynchronous dynamic update, we study the disease transmission in a population initially formed by susceptible individuals due to the introduction of a single mosquito (human) infected. We find that this model exhibits a continuous phase transition related to the existence or non-existence of an epidemic. By means of mean field approximations and Monte Carlo simulations we investigate the epidemic threshold and the phase diagram in terms of the diffusion probability and the infection probability.