Seroprevalence and risk factors associated with Visna/Maedi virus in semi-intensive lamb-producing flocks in northwestern Spain.

A cross-sectional study was carried out to determine Visna/Maedi virus (VMV) seroprevalence and risk factors in semi-intensive lamb-producing flocks as a prelude to establishing a monitoring program in northwestern (NW) Spain. A total of 15,155 serum samples were taken from 78 commercial flocks and were submitted to an indirect VMV ELISA. Association between potential risk factors and seroprevalence at the flock level was assessed using a multivariable logistic regression model. A Generalized Estimating Equations (GEE) model and Exhaustive Chi-squared Automatic Interaction Detector (CHAID) were used to determine the seropositivity against VMV at the individual animal level. Individual seropositivity was 24.8% while 52.6% of the flocks examined had a true seroprevalence ≥1%. Flock size and introduction of new animals in the flock were significantly associated with seropositivity at the flock level. Flock size, sheep-goat contact, type of housing of lambs prior to weaning and age were significantly associated with individual VMV seropositivity. Confinement of lambs in preweaning lamb groups and high sheep-goat contact, regardless of the low number of goats per flock, were risk factors associated with individual VMV seropositivity, suggesting that these two factors are crucial for VMV control in semi-intensive lamb-producing flocks. These factors should be considered for developing more efficient strategies that will reduce the rate of VMV transmission.

[Neonatal herpes simplex encephalitis: two twins, two cases]. / Encefalitis herpética neonatal: dos gemelas, dos casos.

Herpes simplex encephalitis is an infrequent infection with high mortality and morbidity. Antiviral therapies decrease mortality but long term sequelae are still high, so early diagnosis is important for opportune treatment. We present a pair of twins with central nervous system herpes simplex infection during the first month of life. Both twins presented non-specific symptoms and consulted with 48 hours apart needing intensive care admission, the first one for noninvasive mechanical ventilation and the second for hemodynamic support. Diagnosis was made by cerebrospinal fluid PCR, in the first twin at day 9 of disease and in the second at admission. Both twins were treated with acyclovir, but only the second one at the beginning of her illness. Initial study with electroencephalogram and magnetic resonance was normal and cerebrospinal fluid on day 18 of treatment was negative for herpes simplex virus DNA detection in both patients.

Encefalitis herpética neonatal: dos gemelas, dos casos / Neonatal herpes simplex encephalitis: two twins, two cases

Herpes simplex encephalitis is an infrequent infection with high mortality and morbidity. Antiviral therapies decrease mortality but long term sequelae are still high, so early diagnosis is important for opportune treatment. We present a pair of twins with central nervous system herpes simplex infection during the first month of life. Both twins presented non-specific symptoms and consulted with 48 hours apart needing intensive care admission, the first one for noninvasive mechanical ventilation and the second for hemodynamic support. Diagnosis was made by cerebrospinal fluid PCR, in the first twin at day 9 of disease and in the second at admission. Both twins were treated with acyclovir, but only the second one at the beginning of her illness. Initial study with electroencephalogram and magnetic resonance was normal and cerebrospinal fluid on day 18 of treatment was negative for herpes simplex virus DNA detection in both patients.

La encefalitis herpética en una infección poco frecuente, pero que condiciona alta morbilidad y mortalidad. Las terapias antivirales han logrado disminuir la mortalidad pero no las secuelas a largo plazo que siguen siendo altas, por lo que el énfasis está puesto en la precocidad del diagnóstico, en aras de implementar un tratamiento oportuno. Se presenta el caso de dos gemelas con encefalitis causada por virus herpes simplex durante el primer mes de vida. Ambas gemelas presentaron síntomas inespecíficos al mes de vida y consultaron con 48 horas de diferencia, necesitando cuidados intensivos, la primera por requerimientos de ventilación mecánica no invasora y la segunda por inestabilidad hemodinámica. El diagnostico fue realizado por RPC cualitativa en LCR positivo para VHS, en la primera gemela el día 9 de síntomas y en la segunda al momento de su consulta. Ambas gemelas recibieron aciclovir, pero sólo la segunda precozmente, desde el inicio de los síntomas. El estudio inicial en ambas, incluyendo EEG y RM, resultó normal y el LCR del día 18 de tratamiento no presentaba ADN de VHS en ambas pacientes.

Protostrongylid infection in meat sheep from Northwestern Spain: prevalence and risk factors.

2093 Faecal samples from 74 commercial meat ovine flocks were collected and examined by the Baermann-Wetzel method for protostrongylid infection. The risk of being infected by lungworms was evaluated with a data mining classification tree (CHAID), and the intensity of infection with a general linear model (GLM). 242 out of 2093 faecal samples examined were positive for protostrongylid infection (11.6%; 95% CI 10.2-12.9). Only two species were found, Muellerius capillaris (97.9%) and Neostrongylus linearis (5.4%). 50 out of 74 farms presented at least one animal shedding protostrongylid larvae in faeces. All of them held animals infected by M. capillaris and seven presented mixed infections with N. linearis. Average larval output in infected sheep was 11.9 (SD 30.91). This study showed that protostrongylid prevalence in sheep for meat production was determined mainly by a positive interaction with Dictyocaulus filaria infection; other factors that have influenced over protostrongylid infection were age, introducing external animals in the flocks, mixed management with goats and animal density in pastures. Treatment effects on prevalence were only observed in flocks that did not introduce ewes. The lowest protostrongylid prevalence has been reported in flocks without D. filaria infection and without contact with goats.

Efficacy of anthelminthic control programs against natural Muellerius capillaris infection in sheep in the north-west of Spain. Effect on blood gases and pH in venous blood samples.

The field efficacy of a single dose treatment against natural M. capillaris infection using different anthelmintic drugs, extensively employed in ovine parasite control programs in Galicia (N.W. Spain), and the effect of protostrongylid infection on ovine respiratory functions, were evaluated. Five groups (n = 5) of ewes were used in this study; animals were treated with injectable ivermectin 10.2 mg/kg), levamisole (7.5 mg/kg) and albendazole (5 mg/kg) and monitored at 0, 7, 21, 42 and 63 days posttreatment (d.p.t.) by enumeration of the lungworm larvae per gram of faeces (l.p.g.) and determination of gas tension and pH in venous blood using an i-Stat portable clinical analyzer. No statistical difference was found either in larval elimination between untreated and treated groups or in the reduction in larval counts in all of the treated groups. A significant increase in partial oxygen tension (pO2) and saturation (sO2) between day 0 and 7 p.t. was observed in all treated animals. These values decreased significantly at day 21 to previous levels. There were no statistical differences in blood gases between uninfected and treated groups. We can conclude that under Galician field conditions, parasitic control programs are not totally effective against M. capillaris infection.

Seroprevalence of Toxoplasma gondii and Neospora caninum in wild and domestic ruminants sharing pastures in Galicia (Northwest Spain).

The prevalence of antibodies to the protozoan parasites Toxoplasma gondii and Neospora caninum were investigated by the direct agglutination test (DAT) and cELISA, respectively, in 160 roe deer (Capreolus capreolus), 177 sheep and 178 cattle sharing pastures in Galicia (Northwest Spain). The seroprevalence for T. gondii was 13.7% in roe deer, 57% in sheep and 7.3% in cattle. The seroprevalence for N. canimum was 6.8%, 10.1% and 24.1% in roe deer, sheep and cattle, respectively. Statistically significant differences were observed between sheep and the other species for T. gondii and between cattle and the other ruminants for N. caninum. Only 19/515 animals were positive for both, T. gondii and N. caninum. Statistically significant differences were observed among different geographical areas for T. gondii but not for Neospora, seroprevalence being higher in the coastal area lower than in other areas. This study reveals a widespread exposure to T. gondii in Galician ruminants, and therefore, those species, particularly sheep, should be regarded as a potential source of infection for humans.

Local and systemic cytokine responses during larval penetration in cattle experimentally infested with Hypoderma lineatum (Diptera: Oestridae).

Local and systemic cytokine responses were studied in 3 groups of cattle, with 4 animals each, experimentally infested with Hypoderma lineatum (De Villers) first instars (L1). The first group was undergoing a primary infestation (G-1), the second group was undergoing a secondary infestation (G-2) and the third group was infested for their third consecutive year (G-3). Cattle were infested with 25 L1 deposited on the skin. Blood and skin samples were taken at 0, 6, 12, 48, 96 and 144h post-infestation (h.p.i.). Interleukin 10 (IL-10), IL-4 and interferon gamma (IFN-gamma) production was studied by immunohistochemistry and sandwich ELISAs. IL-4(+) cells showed a significant increase at 6h.p.i. in both reinfested groups (G-2 and G-3) when compared with G-1. In all groups the number of IL-4(+) cells decreased significantly at 48h.p.i. IL-10(+) cells increased in G-1 at 6 and 48h.p.i., whereas in both reinfested groups increased at 12h.p.i. with a peak at 48h.p.i. IFN-gamma(+) cells showed a significant increment at 6h.p.i. in all groups, followed by a rapid descent at 12 (G-1 and G-2) and 48h.p.i. (G-3). Penetration of the skin by H. lineatum did not have any significant effect on IFN-gamma serum concentrations and, except for IL-10 there were no correlation between local production and serum concentrations of cytokines. The increase of both Th1 (IFN-gamma) and Th2-type cytokines (IL-4 and IL-10) indicates that bovine T-cell response during the first phases of the infestation by H. lineatum is apparently a Th0 response.

Immunomodulatory effect of Hypoderma lineatum antigens: in vitro effect on bovine lymphocyte proliferation and cytokine production.

This study examines the immunomodulatory effect of a crude larval extract (CLE), obtained from first stage larvae (L1) of H. lineatum, and the purified fractions hypodermin A (HyA), HyB and HyC. Proliferative responses of peripheral blood mononuclear cells (PBMC) from uninfested and previously infested cattle and the production of the cytokines IL-10, IL-4 and IFN-gamma, in response to concanavalin A (Con A), were determined. The stimulation index of peripheral blood mononuclear cells from uninfested cattle was significantly lower than that from infested animals with the different antigens assayed. The HyA was the antigen that most inhibited the proliferative response, followed by the HyB, the HyC and the CLE. This hypodermin provoked an increase of IFN-gamma and a suppression of IL-10 production that would support a Th1-like cytokine response. The HyB reduced the production of IL-10 stimulated by the Con A in cultures from infested animals. The HyC did not modulate the production of cytokines. Finally, the CLE induced a marked suppression in the production of the different cytokines in cultures from naïve and previously sensitized animals. Our results indicate that Hypoderma larval secretions are comprised of different components (hypodermins) that individually induce distinct but partially overlapping modulatory responses.

Occurrence and larval growth of Hypoderma lineatum in the oesophagi of cattle from northwest Spain: influence of geographical and climatic conditions.

From March 2004 to March 2005, 862 bovine oesophagi were collected at weekly intervals from a slaughterhouse in Lugo in northwest Spain in order to establish the occurrence and chronobiology of the first-instar (L1) oesophageal phase of Hypoderma lineatum (De Villers) (Diptera: Oestridae) in different climatic areas from this region. First instars were observed in oesophagi from May to February (10 months/year). The annual prevalence was 18.2%. Maximum prevalence occurred in July and October. Prevalence in the coastal area was significantly lower than in the other areas. A total of 846 L1s were extracted from 120 infested oesophagi, 814 from the submucosa and 32 from external locations. The mean intensity of infestation was low (7.6 +/- 6.2); only 3.3% of the oesophagi harboured more than 30 L1s. Maximum numbers of L1/animal were observed in November and January. There were no differences in intensity of infection between climatic areas. The length of L1s ranged from 4.6 +/- 0.86 mm in May to 14.6 +/- 1.04 mm in January. The growth of larvae collected from external sites was parallel to those found in the submucosa. Mountainous areas produced the L1s of greatest length, followed by central and transition zones and, finally, coastal zones. To avoid adverse reactions resulting from the application of systemic insecticides, it will be necessary to adjust the time at which cattle are treated according to geographical or climatic area.

Hendidura esternal total en un recién nacido y parcial en una niña de 4 años / Cleft sternum: 2 clinical cases

La hendidura esternal es una malformación congénita de la pared torácica que se origina en una falla embrionaria de la fusión de las valvas esternales en la línea media. El defecto debe ser reparado precozmente al nacer, para reestablecer la protección ósea de las estructuras del mediastino, prevenir el movimiento paradojal de las vísceras en la respiración, eliminar la deformidad visible y permitir un desarrollo normal de la caja torácica. Objetivo: Notificar 2 pacientes portadores de esta infrecuente malformación y revisar sus características clínicas, permitiendo realizar un diagnostico preciso, orientar el estudio y definir un adecuado tratamiento. Casos clínicos: Recién nacido masculino con una hendidura esternal completa que provoca un "distress" respiratorio y una preescolar de 4 años, con una hendidura parcial del tercio superior esternal, asociada a una cardiopatía congénita operada. Los pacientes son sometidos a una reparación quirúrgica que permitió un alta precoz y una evolución clínica favorable. Conclusión: La Hendidura Esternal es una malformación de baja frecuencia que debe ser corregida precozmente para evitar el uso de técnicas de mayor complejidad con resultados variables.

Effects of ageing on allocentric and egocentric spatial strategies in the Wistar rat.

This study was designed to assess the effect of ageing on spatial (allocentric and egocentric) strategies in rats. Two different tasks were designed for this purpose: one involving Morris' circular pool (distal extramaze cues) and another using the T water maze (egocentric cues). In the first task, the aged rats showed some difficulty in acquiring allocentric spatial learning skills. After increasing the number of trials in this task, there was no significant improvement in the performance of the aged group of rats compared to the adult group. However, in the second spatial task (using egocentric cues), both age groups gave a similar performance. Therefore, the effect of ageing on spatial learning depends on the strategy required to acquire this learning.

Enterocolitis necrotizante neonatal / Neonatal necrotizing enterocholitis

Una excelente revisión de la fisiopatología y normas de conducta ante el grave cuadro de la enterocolitis necrotizante neonatal