Tick-borne encephalitis (TBE) is an emerging viral zoonosis and is endemic from Japan, China, Mongolia and Russia, to Central Europe and France. There is no specific treatment and TBE can be fatal. The four licensed prophylactic vaccines are produced according to WHO manufacturing requirements. Large clinical trials and postmarketing surveillance demonstrated safety and efficacy of the two European vaccines. The two Russian vaccines showed their effectiveness in daily use, but limited published data are available on controlled clinical trials. Vaccination recommendations in endemic areas vary significantly. In some countries, public vaccination programs are implemented. The WHO has recently issued recommendations on evidence-based use of TBE vaccines. However, more data are needed regarding safety, efficacy and long-term protection after vaccination.

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1997 (11, 45). This rise was largely due to a 20% increase in the incidence of TB in African countries that are heavily affected by the human immunodeficiency virus (HIV) infection and AIDS epidemic (45). HIVinfected persons have an increased risk of developing clinical TB (20). This risk was previously attributed mainly to an increased risk of reactivation of a latent infection (15, 34). DNA fingerprinting of the Mycobacterium tuberculosis genome has been used extensively to explore the dynamics of TB transmission (5, 40). In general, the simultaneous accumulation of mycobacterial isolates with identical fingerprints, i.e., clusters, has been attributed to recent infection, whereas isolates with unique fingerprints are most commonly associated with endogenous reactivation (23,40). Studies from industrialized countries in which DNA fingerprinting of insertion element IS6110 of the M. tuberculosis genome has been used (37) have shown that nearly two-thirds of M. tuberculosis isolates from HIVinfected patients appear in clusters, suggesting recent infection (2, 36). Further support for this suggestion is provided by DNA fingerprinting of nosocomial TB outbreaks, including transmission of multidrug-resistant strains (6,7,12). These studies have demonstrated rapid progression to clinical disease in immunosuppressed HIV-infected individuals.In population-based studies from sub-Saharan Africa, where the rate of M. tuberculosis transmission is very high, the proportion of clustered M. tuberculosis isolates from patients with smear-positive TB has varied from 38 to 47% (18, 28, 29, 44). The proportion of isolates appearing in clusters was even higher (67%) for isolates from male patients in a gold-mining community in South Africa with a particularly high incidence of TB (16). In those studies, however, isolates appearing in clusters were equally distributed among HIV-positive and HIV-negative TB patients.During the 1990s Ethiopia experienced a severe HIV epidemic, with the prevalence of pregnant women in Addis Ababa infected with HIV rising from 6% in 1989 to 18% in 1997 (13). A TB epidemic has coincided with this development, and in 1999, Ethiopia was ranked number 8 among the 23 countries with the highest total TB burden (45). In 1997, about 30% of all new TB cases were believed to occur in HIV-positive individuals (11). In areas such as Ethiopia where HIV infection is highly endemic, the relative importance of reactivation and recent infection is not known. Information in this field may

In a setting with a high prevalence of HIV we studied (i) the prevalence of pulmonary tuberculosis (PTB) and HIV; (ii) clinical and epidemiological characteristics of PTB; and (iii) the usefulness of standard procedures for diagnosing PTB. Of 509 consecutive outpatients evaluated on clinical suspicion of PTB in Addis Ababa, 33.0% were culture-verified as having PTB. PTB patients, non-TB patients and controls were HIV-1-positive in 57.1%, 38.5% and 8.3% of cases, respectively. Predictors for culture-verified PTB were age < 25 y, male gender and the presence of HIV and fever, whereas profound weight loss indicated HIV infection. Diagnosis of PTB based on clinical symptoms, sputum microscopy for acid-fast bacilli and chest radiography was sensitive (86.7%) but unspecific (64.1%). In HIV-positive patients both sensitivity and specificity were significantly lower (p < 0.05). HIV-related pulmonary infections are often misinterpreted as smear-negative PTB. HIV screening is therefore warranted not only in cases of verified TB but also as part of the diagnostic work-up in patients with respiratory symptoms suggestive of PTB. Also, increased awareness of, and improved diagnostic tools for, HIV-related pulmonary infections other than PTB are required, together with algorithms for patients with suspected PTB.

The purpose of this study was to compare the sampling efficacy of rayon swabs and nylon flocked swabs, and of oropharyngeal and nasopharyngeal specimens for the detection of respiratory viruses in elderly patients. Samples were obtained from patients 60 years of age or above who were newly admitted to Sorlandet Hospital Arendal, Norway. The patients were interviewed for current symptoms of a respiratory tract infection. Using rayon swabs and nylon flocked swabs, comparable sets of mucosal samples were harvested from the nasopharynx and the oropharynx. The samples were analysed using real-time polymerase chain reaction (PCR) methods. A total of 223 patients (mean age 74.9 years, standard deviation [SD] 9.0 years) were swabbed and a virus was recovered from 11% of the symptomatic patients. Regardless of the sampling site, a calculated 4.8 times higher viral load (95% confidence interval [CI] 1.3–17, p = 0.017) was obtained using the nylon flocked swabs as compared to the rayon swabs. Also, regardless of the type of swab, a calculated 19 times higher viral load was found in the samples from the nasopharynx as compared to the oropharynx (95% CI 5.4–67.4, p < 0.001). When swabbing for respiratory viruses in elderly patients, nasopharyngeal rather than oropharyngeal samples should be obtained. Nylon flocked swabs appear to be more efficient than rayon swabs.