The vector ecology of introduced Culex quinquefasciatus populations, and implications for future risk of West Nile virus emergence in the Galápagos archipelago.

Culex quinquefasciatus Say (Diptera: Culicidae), an important vector of West Nile virus (WNV) in the U.S.A., was first detected on the Galápagos Islands (Ecuador) in the 1980s. However, little is known of its ecology, distribution or capacity for arbovirus transmission in the Galápagos. We characterize details of lifecycle (including gonotrophic period), temporal abundance, spatial distribution, vector competence and host-feeding behaviour. Culex quinquefasciatus was detected on five islands of the Galápagos during 2006-2011. A period of 7-14 days was required for egg-adult emergence; water salinity above 5 ppt was demonstrated to hinder larval development. Blood-meal analysis indicated feeding on reptiles, birds and mammals. Assessment of WNV vector competency of Galápagos C. quinquefasciatus showed a median infectious dose of 7.41 log10 plaque-forming units per millilitre and evidence of vertical transmission (minimal filial infection rate of 3.7 per 1000 progeny). The distribution of C. quinquefasciatus across the archipelago could be limited by salt intolerance, and its abundance constrained by high temperatures. Feeding behaviour indicates potential to act as a bridge vector for transmission of pathogens across multiple taxa. Vertical transmission is a potential persistence mechanism for WNV on Galápagos. Together, our results can be used for epidemiological assessments of WNV and target vector control, should this pathogen reach the Galápagos Islands.

Genomic epidemiology of the emerging pathogen Batrachochytrium dendrobatidis from native and invasive amphibian species in Chile.

Emerging fungal diseases represent a threat to food security, animal and human health worldwide. Amphibian chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has been associated with catastrophic and well-documented amphibian population declines and extinctions. For the first time, Bd was cultured from native and non-native wild amphibians in Chile. Phylogenomic analyses revealed that Chilean isolates AVS2, AVS4 and AVS7 group within the global panzootic lineage of Bd (BdGPL) in a single highly supported clade that includes a genotype previously isolated from the United Kingdom. Our results extend the known distribution of BdGPL in South America and suggest a single and relatively recent introduction of BdGPL into the country, providing additional support to the role of anthropogenic activity in the global spread of this panzootic lineage.

Dynamics and genetics of a disease-driven species decline to near extinction: lessons for conservation.

Amphibian chytridiomycosis has caused precipitous declines in hundreds of species worldwide. By tracking mountain chicken (Leptodactylus fallax) populations before, during and after the emergence of chytridiomycosis, we quantified the real-time species level impacts of this disease. We report a range-wide species decline amongst the fastest ever recorded, with a loss of over 85% of the population in fewer than 18 months on Dominica and near extinction on Montserrat. Genetic diversity declined in the wild, but emergency measures to establish a captive assurance population captured a representative sample of genetic diversity from Montserrat. If the Convention on Biological Diversity's targets are to be met, it is important to evaluate the reasons why they appear consistently unattainable. The emergence of chytridiomycosis in the mountain chicken was predictable, but the decline could not be prevented. There is an urgent need to build mitigation capacity where amphibians are at risk from chytridiomycosis.

Urban domestic dog populations as a source of canine distemper virus for wild carnivores in the Coquimbo region of Chile.

Urban areas can support dog populations dense enough to maintain canine distemper virus (CDV) and can be a source of infection for rural dogs and free-ranging carnivores. The aim of this study was to investigate the relationships between urban and rural domestic dog and wild carnivore populations and their effects on the epidemiology of CDV to explain retrospectively a CD outbreak in wild foxes in 2003. From 2005 to 2007 a cross-sectional household questionnaire survey was conducted in Coquimbo and Ovalle cities, in three towns and in rural sites along two transects from these cities to the Fray Jorge National Park (FJNP) in the Coquimbo region, Chile. Blood samples were collected from unvaccinated dogs at surveyed households and from free-ranging foxes in rural areas along the transects. The seroprevalence of CDV in domestic dogs was higher in urban than in rural areas and in the later was highest in dogs born before 2001-2002. The seroprevalence of CDV in foxes was higher in areas closer to human settlements. A high seroprevalence in dogs born before 2001-2002 further supports a link between CDV patterns in rural dog and fox populations. In our study area, urban dogs are proposed to be the source of CDV infection to wild carnivores. The large dog population size and density detected in Coquimbo and Ovalle provides optimal conditions for maintaining a large and dense susceptible population of dogs, which can act as a reservoir for highly infectious diseases and could have been the source of infection in the CD outbreak in wild foxes.

Demography of domestic dogs in rural and urban areas of the Coquimbo region of Chile and implications for disease transmission.

A cross-sectional household questionnaire survey was conducted along two transects (80 and 45km long) from Coquimbo and Ovalle cities to the Fray Jorge National Park (FJNP) in the Coquimbo region of Chile in 2005-2007 to investigate the demography of dogs in the context of a study of canine infectious diseases. Data were collected on the number of dogs per household, fecundity, mortality, and sex and age distribution. The results from 1021 households indicated that dog ownership was common, with a higher proportion of households owning dogs in rural areas (89%), than in towns (63%) or cities (49%). Dog density ranged from 1380+/-183 to 1509+/-972 dogs km(-2) in cities, from 119+/-18 to 1544+/-172 dogs km(-2) in towns, and from 1.0+/-0.4 to 15.9+/-0.4 dogs km(-2) in rural sites. The dog population was estimated to be growing at 20% in cities, 19% in towns and 9% in rural areas. The human:dog ratio ranged from 5.2 to 6.2 in cities, from 2.3 to 5.3 in towns, and from 1.1 to 2.1 in rural areas. A high percentage of owned dogs was always allowed to roam freely in the different areas (27%, 50% and 67% in cities, towns and rural areas, respectively). Observations of free-roaming dogs of unknown owner were reported from a greater proportion of respondents in cities (74%), followed by towns (51%) and finally by rural areas (21%). Overall only 3% of dogs had been castrated. In addition, only 29% of dogs were reported to have been vaccinated against canine distemper virus (CDV) and 30% against canine parvovirus (CPV). The higher population size and density, higher growth rate and a higher turnover of domestic dogs in urban than in rural areas and the poorly supervised and inadequately vaccinated dog populations in urban areas suggest that urban areas are more likely to provide suitable conditions for dogs to acts as reservoirs of pathogenic infections.

Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America.

Epidermal changes caused by a chytridiomycete fungus (Chytridiomycota; Chytridiales) were found in sick and dead adult anurans collected from montane rain forests in Queensland (Australia) and Panama during mass mortality events associated with significant population declines. We also have found this new disease associated with morbidity and mortality in wild and captive anurans from additional locations in Australia and Central America. This is the first report of parasitism of a vertebrate by a member of the phylum Chytridiomycota. Experimental data support the conclusion that cutaneous chytridiomycosis is a fatal disease of anurans, and we hypothesize that it is the proximate cause of these recent amphibian declines.

Breast-feeding and health in the 1980s: a global epidemiologic review.

PIP: In view of the significant and articulate minority view among pediatricians that breast feeding is not "worth the bother" in developed countries, this review of the literature delves into the evidence from both developed and developing countries for the advantages of breastfeeding, both in infants and for long-term health. Infants in developed settings experience twice the hospitalization rate and more severe illness from lower respiratory tract infection, primarily respiratory syncytial virus. In developing countries the mortality risk is 4-fold. for otitis media, the relative risks were 3.3-4.3 for Finnish infants. Bacterial meningitis and/or bacteremia had a 4-fold risk for hospitalization in a Connecticut study, and a 3-fold relative risk in 2 developing country studies. Human milk was the best preventative for bacteremia and necrotizing enterocolitis in prematures in British neonatal units. A 20-fold reduction in neonatal deaths occurred in Philippine study of breastfeeding, especially in low birth weight babies. Diarrhea causes the most infant mortality in developing nations, where bottle-feeding raises rates 14-fold. In the U.S. estimated relative risks is 3.7 for diarrheal mortality. Sudden infant death is about 1/5 less common in U.S. breast fed babies than in bottle fed. There is evidence for better long-term health after breast feeding in disorders such as celiac disease, Crohn disease, ulcerative colitis, insulin-dependent diabetes mellitus, thyroid disease, malignant lymphoma, chronic liver disease, atopic dermatitis, and food allergies. The design of good studies of protection conferred by breast feeding, and the possible modes of action of breast milk are discussed.^ieng

Reemplazo del astragalo por una protesis de silastico. / Replacement of the astragalus by means a siliastic prosthesis

Se menciona la frecuencia de necrosis avascular postraumatica del astragalo. Se hacen consideraciones acerca de los procedimientos quirurgicos indicados en el citado padecimiento. Se comenta la importancia del astragalo en la biomecanica de tobillo y pie, lo que justifica su preservacion o reemplazo. Se describe la tecnica para la elaboracion de un astragalo de silastico y su aplicacion en dos casos clinicos, de los cuales se comenta la tecnica y sus resultados

Morbidity in breast-fed and artificially fed infants. II.

The advantages of breast-feeding in reducing morbidity was previously shown in a group of rural infants. Those observations are extended and refined. The protection afforded by breast-feeding is greatest during the early months, increases with the duration of breast-feeding, and appears to be more striking for serious illness. It operates independently of the effect of associated factors such as socioeducational status, family size, day-care exposure, and birth weight.