[Active surveillance for scrapie in the Netherlands: effect of a breeding programme on the prevalence of scrapie in sheep (2002-2010)?]. / Acht jaar actieve scrapiesurveillance in Nederland: het effect van het fokprogramma op de prevalentie van scrapie bij het schaap (2002-2010).

The susceptibility of sheep to scrapie is modulated by the prion protein (PrP) genotype of the animal. An ambitious voluntary scrapie control programme was started in the Netherlands in 1998, based on selection of rams with theARR/ARR genotype for breeding. This programme was followed by an obligatory programme in 2004; the programme has been voluntary since 2007. We monitored the prevalence of PrP genotype frequencies and the prevalence of scrapie in the Dutch sheep population between 2002 and June 2010. Results showed that selection for scrapie-resistant sheep resulted in an increase in the ARR allele frequency in the Dutch national flock from 37.5% in 2005 to 61.4% in 2009. Moreover, surveillance data showed that there was a significant decrease in the prevalence of scrapie a few years after the start of the obligatory breeding programme, from more than 0.2% in 2004 to 0.015% in 2009. This decrease is a consequence of the increased number of scrapie-resistant sheep in the Dutch sheep population. To date, the results and the models based on the data show that the selective breeding programme should be continued for several years in order to successfully eradicate scrapie. It will be important to monitor the PrP frequency and scrapie prevalence in the Dutch sheep population in the coming years.

Course and complications of varicella zoster ophthalmicus in a high HIV seroprevalence population (Cape Town, South Africa).

AIM: To describe the course and complications of varicella zoster ophthalmicus (VZO) in patients attending an eye clinic in a community with a high HIV seroprevalence. STUDY DESIGN: Prospective cohort study of consecutive patients presenting to a tertiary hospital eye clinic with VZO. METHOD: Patients recruited in 2001 and 2002 received standardized initial topical and systemic management, which was then modified according to complications. Information on the course and complications of the disease was entered in a database prior to statistical analysis. RESULTS: Information on 102 patients who had 250 visits to the eye clinic was collected. HIV serology was positive, negative, and unknown in 66, 22, and 14 patients, respectively. The most common complication was uveitis (40/102). Median delay from onset of rash to starting acyclovir was 5 days. Complications were present in 33 patients at the first visit. Complications were commoner in patients with positive Hutchinson's sign and were less common at CD4 counts <200. At CD4 counts, > or =200 HIV infection had little effect on the course and complications of VZO. Timing of commencement of Acyclovir therapy within or after 72 h had no demonstrable effect on the incidence of new complications. CONCLUSION: In a resource-limited setting, patients with the following characteristics should have immediate ophthalmic assessment: symptoms suggesting ocular complications or the presence of Hutchinson's sign. All VZO patients should receive antiviral therapy at the first doctor's visit even if they present >72 h after onset of the rash.

Virulence and genotype of a bovine herpesvirus 1 isolate from semen of a subclinically infected bull.

A bovine herpesvirus 1 (BHV-1) isolate from the semen of a subclinically infected bull was administered to cattle by various routes to assess its virulence. Cattle that were artificially inseminated or inoculated intrapreputially did not develop clinical signs, but did transmit the virus to contact cattle. However, the isolate induced severe signs of rhinotracheitis and vulvovaginitis in cattle that were inoculated by the intravaginal, intranasal or intravenous routes, but did not infect the fetus. The isolate was therefore not of low virulence. Analysis with DNA restriction enzymes could not assign the isolate to either the BHV-1.1 or BHV-1.2 genotype.