Effectiveness of disinfectant treatments for inactivating Piscirickettsia salmonis.

This short communication investigated in vitro differences between commercial disinfectants types (n = 36), doses of application, and time of action in the elimination of Piscirickettsia salmonis, the most important bacterium affecting farmed salmon in Chile. Seven different treatments were examined, including active and inactive chlorine dioxides, glutaraldehyde, hypochlorite disinfectants and detergents, peracetic acid, peroxides and other miscellaneous methods A 3 replicate set of each of the sample groups was stored at 20 °C and 95% relative humidity and retested after 1, 5 and 30 min with varying doses (low, recommended and high doses). Multiple comparison tests were performed for the mean log CFU/ml among different disinfectant types, dose (ppm) and time of exposure (minutes) on the reduction of P. salmonis. Overall, disinfection using peracetic acid, peroxides, and both active and inactive chlorine dioxides caused significantly higher reduction of >7.5 log CFU/ml in samples, compared to other tested sanitizers. The lowest reduction was obtained after disinfection with hypochlorite detergents. As expected, as doses and time of action increase, there was a significant reduction of the overall counts of P. salmonis. However, at lowest doses, only use of paracetic acids resulted in zero counts. Implementation of effective protocols, making use of adequate disinfectants, may enhance biosecurity, and ultimately, mitigate the impact of P. salmonis in farmed salmon.

Use of vaccines and factors associated with their uptake variability in dogs, cats and rabbits attending a large sentinel network of veterinary practices across Great Britain.

Vaccination remains a mainstay of companion animal population health. However, how vaccine use at a population level complies with existing guidelines is unknown. Here we use electronic health records to describe vaccination in dogs, cats and rabbits attending a large sentinel network of UK veterinary practices. In total, 77.9% (95% CI: 77.6-78.1) of animals had recorded vaccinations. The percentage of animals with recorded vaccinations was higher in dogs, neutered animals, in insured dogs and cats and in purebred dogs. Vaccination rates varied in different regions of Great Britain in all species. Dogs and cats belonging to owners living in less deprived areas of England and Scotland were more likely to be recorded as vaccinated. In the vaccinated population, cats received more core vaccines per year of life (0.86) than dogs (0.75), with feline leukaemia vaccines almost as frequent as core vaccines. In dogs, leptospira vaccines were more frequent than core vaccines. This descriptive study suggests a substantial proportion of animals are not benefiting from vaccine protection. For the first time, we identify potential factors associated with variations in recorded vaccination frequency, providing a critical baseline against which to monitor future changes in companion animal vaccination and evidence to inform future targeted health interventions.

Spatial Epidemiology and Risk Factor Analysis of White Spot Disease in the Shrimp Farming Industry of Sinaloa, Mexico, from 2005 to 2011.

White spot disease (WSD), caused by the white spot syndrome virus, is currently one of the primary causes of mortality and economic losses in the shrimp farming industry worldwide. In Mexico, shrimp production is one of the most important primary activities generating an annual income of USD 711 million. However, WSD introduction in 1999 had a devastating impact for the Mexican shrimp industry. The aim of this study was to characterize the WSD spatio-temporal patterns and to identify the primary risk factors contributing to WSD occurrence from 2005 to 2011 in Sinaloa, Mexico. We used data collected by the 'Comité Estatal de Sanidad Acuícola de Sinaloa' from 2005 to 2011 regarding WSD outbreaks as well as environmental, production and husbandry factors at farm level. The spatio-temporal patterns of WSD were described using space-time scan statistics. The effect of 52 variables on the time to WSD outbreak occurrence was assessed using a multivariable Cox proportional hazards model. Results reveal that WSD risk and survival time were not homogeneously distributed as suggested by the significant clusters obtained using the space-time permutation model and the space-time exponential model, respectively. The Cox model revealed that the first production cycle [hazard ratio (HR) = 11.31], changes from 1 to 1.4°C of temperature oscillation caused by 'El Niño'/'La Niña' events (HR = 1.44) and high average daily growths (HR = 1.26) were significantly associated with lower survival (i.e. shorter time to WSD outbreak) on farm. Conversely, shrimp weight at the moment of the outbreak (HR = 0.159), changes from -0.9 to -0.5°C of temperature oscillation caused by 'El Niño'/'La Niña' events (HR = 0.540), high superficial water temperature during the pound stocking (HR = 0.823) and high (>100) number of days of culture (HR = 0.830) were factors associated with higher survival. Results are expected to inform the design of risk-based, intervention strategies to minimize the impact of WSD in Mexico.

Proposal of a production and management index (PMI) for tilapia farms.

Tilapia is one of the most important species in aquaculture; however, there is no available index to show the performance of a production unit. It is desirable to assess the productivity using indexes, such as the production and management index for shrimps and the European production efficacy factor for broilers. These indexes are based on data production: growth, survival, and feed conversion of a full production cycle. Taking into account these parameters, we propose a production and management index (PMI) for tilapia that is applicable for a specific period of the production cycle. For the construction and validation of the PMI we have used production data from 8,614 monthly records of 2 tilapia farms in Huila Department (Colombia), and because of the complexity of tilapia management, different anomalous situations have been detected and then defined as exceptions. As a result, 419 records were considered extreme values because 1 or more exceptions were met. The value of the PMI varies from 0 (the worst situation) to 3.55, which reflects high variability. We have constructed a PMI for tilapia as the product of 3 elements to obtain a positive value index. Instead of classic parameters, we had to calculate an adapted version of them: the relative average daily growth, the survival (as a complementary value of the estimated monthly mortality), and a feed conversion ratio index. To assess the utility of the PMI, some comparisons were performed using records from black and red tilapia. We observed significant differences depending on tilapia strain (PMI = 1.0248 vs. PMI = 1.1661; < 0.001), age (better values for small fish), and season (PMI = 1.0847 vs. PMI = 1.1011; = 0.026). According to these results, we can conclude that the PMI could be a useful tool for tilapia farmers, despite the complexity of the calculation.

Microscopic abnormalities in the liver of two patients with Porphyria variegata.

In contrast to Porphyria cutanea tarda (PCT), which is characterized by constant hepatic involvement, the liver seems to be unaltered in Porphyria variegata (PV). However, the authors have found microscopic alterations in the liver of 2 patients with PV (mild inflammation and fibrosis of the portal tracts and the presence of iron deposits in one of the cases). Although these changes could be attributed to other causes, the hypothesis of possible liver involvement in PV is not excluded.

[Early forms of porphyria cutanea tarda. Apropos of 2 cases with a study of familial enzymatic deficiency and definition of the mode of genetic transmission]. / Les formes précoces de porphyrie cutanée tardive. A propos de deux observations avec étude du déficit enzymatique de la famille et précision du mode de transmission génétique.

The authors report two cases of cutaneous porphyria in children aged 6 and 9 respectively. The clinical and biochemical patterns were similar to those of porphyria cutanea tarda. The manifestations were drug-induced in both cases (by sulfonamides and griseofulvin in the first patient, and by hydantoin and benzodiazepine in the second). The clinical examination and the determination of porphyrins in the relatives showed no abnormalities. However, the study of the erythrocyte uroporphyrinogen decarboxylase showed 50 p. 100 reduced activity in the father and grandfather of the first patient, and in the second case's mother. Treatment with chloroquine (3 mg/kg/week) produced the total remission of both cases with no recurrences in 4 and 2 years respectively.

Photocontact dermatitis to cobalt salts.

4 patients with chronic photocontact dermatitis were sensitive to cobalt salts. They presented as cases of contact dermatitis from cement or pig fodder with persistent lesions on exposed areas. Only 2 of them had standard patch test positive reactions to chromate and cobalt, but all showed positive photo-patch tests to cobalt. Photo-oxidation tests proved that cobalt salts are photosensitizing. Exposure to cobalt salts was responsible for the patients' chronic actinic dermatitis.

Hepatoerythropoietic porphyria: a new uroporphyrinogen decarboxylase defect or homozygous porphyria cutanea tarda?

Uroporphyrinogen decarboxylase levels were measured in haemolysed whole blood or fibroblasts from 3 unrelated patients with hepatoerythropoietic porphyria (HEP) and in 4 unrelated patients with familial porphyria cutanea tarda, a condition in which the enzyme is defective. In HEP patients enzyme activities were 7% of normal in erythrocytes and 8% of normal in cultured skin fibroblasts. All the features of HEP, including the characteristic accumulation of protoporphyrin in erythrocytes, are secondary to this enzyme defect. The father of 1 HEP patient was heterozygous for the same enzyme defect. He also had uroporphyrinuria and was therefore indistinguishable from patients with subclinical familial porphyria cutanea tarda. It is suggested that patients with HEP are homozygous for the gene that causes porphyria cutanea tarda.

[Effect of chloroquine in porphyria cutanea tarda]. / Efecto de la cloroquina en la profiria cutánea tarda.

The treatment of Porphyria Cutaneous Tarda (PCT) has greatly improved by the introduction of low-dose chloroquine. The authors report the results in the treatment of 17 patients presenting PCT. The clinical and biological controls of these patients at the 6th and 12th months of treatment showed the disappearance of clinical signs and the normalization of liver function tests and porphyrin excretion between and 6th and the 12th months of treatment in all the cases.

Effects of hypo- and hyper-thyroidism on in vivo lipogenesis in fed and fasted rats.

Thyroidectomized rats (T) daily injected with either 0, 0.1, 1.8 or 25 microgram of L-thyroxine/100 g body wt. were compared with intact controls (C). The appearance of radioactivity in fatty acids 30 min after the i.p. injection of (3-14C)pyruvate was reduced in adipose tissue and enhanced in liver of T+25, being no differences between the other groups and C. (14C)-Fatty acids are reduced with 3 h of fasting only in the adipose tissue of T+1.8 and C, while 24 h produces a reduction in liver in the T+1.8, T+25 and C, and in adipose tissue in the T+1.8 and C animals. The highest percentage of radioactivity was observed in the liver glyceride glycerol fraction, being greater in T+25 than in the other groups. Fasting produces an increment in the (14C)-glyceride glycerol fraction. Being significant only in thehypothyroid animals in both liver and adipose tissue. The most sensitive parameter to fasting was the formation of (14C)-non-saponifiable lipid in both the C and T+1.8 animals, while it does not change in T+0 or T+0.1, but is enhanced within 24 h in the adipose tissue of T+25. It is proposed that most of the observed changes are due to the other endocrine disfunction s which appear in hypo- and hyperthyroidism, as the in vivo results do not comply with in vitro effects of thyroxine onlipogenesis of others.

Adipose tissue cellularity in hypo-and hyperthyroid rats.

To determine adipose tissue cellularity in hypo- and hyperthyroidism, male rats were thyroidectomized after weaning (T) and injected daily with either 0, 0.1, 1.8 or 25 microgram of L-thyroxine/100 g body weight for 40 days. They were compared with intact controls (C). Both epididymal fat-pad weight and adipocyte diameter were reduced in T+0, T+0.1 and T+25 animals. When corrected per unit of body weight, the diameters of adipocytes from T+0 and T+0.1 animals were larger than in the other groups. Those same animals have reduced absolute adipocyte number but not when corrected per unit of body weight. The fat-pad protein concentration varied conversely with the fat cell diameter. These findings indicate that thyroid hormone deficiency reduces the proliferation of fat cells in parallel with body growth while hyperthyroidism causes reduction in the size, but not the number, of fat cells which corresponds to its depletion of fat storage.