Increased number of dengue cases in Swedish travellers to Thailand.

Between 2004 and 2008, around 30-60 cases of dengue fever in travellers were reported annually in Sweden. Over 75% of cases in 2005-2008 were infected when travelling to Southeast Asia, most if them in Thailand, one of the Swedes most popular holiday destinations. Since 2007, we have observed a 55% increase in the number of dengue fever cases reported per month, with 17 cases reported in January 2009 alone.

The epidemiology of hepatitis C virus infection in Sweden.

In Sweden, infection with hepatitis C virus (HCV) has been a notifiable disease since 1990, when diagnostic methods became available. Blood donor screening indicated that about 0.5% of the Swedish population (9 millions) had been HCV infected. Here we present the Swedish hepatitis C epidemic based on data from all the HCV notifications 1990-2006. During this time about 42,000 individuals (70% men) were diagnosed and reported as HCV infected. The majority (80%) were born in 1950 or later, with a high percentage (60%) born in the 1950s and 1960s. Younger people, 15-24 years old at notification, were reported on the same level each year. The main reported routes of HCV transmission were intravenous drug use in 65%, blood transfusions/products in 6%, and sexual in 2%, though unknown or not stated in 26%. Approximately 6,000 of all notified individuals have died during the study period. To conclude, the Swedish HCV epidemic is highly related to the increase of intravenous drug use in the late 1960s and 1970s, with a high proportion of people now chronically infected for more than 25 years, resulting in an increase of severe liver complications in form of cirrhosis and hepatocellular carcinoma. Furthermore the unchanged number of notifications of newly infected younger people indicates an ongoing HCV epidemic.

HIV-antibody testings among injecting drug users (IDUs) in the Stockholm area, 1984-91: information compiled from testing laboratories.

The available information about testings for HIV antibodies in injecting drug users (IDUs) carried out in Stockholm between 1984 and 1992 has been compiled. These testings were carried out mainly in special settings. The use of codes (the first 2 digits giving the age and the last 4 the 6 and checking figures in the individual's personal identity number) precluded exact identification of individuals; in most cases, however, complementary information made it possible to recognize patients at follow-up. The data indicated that 9,150 persons associated with current or previous drug addiction were tested. The first extensive testings were performed in 1985 and 1986. After this period, 4,500 persons were retested. 11% of the IDUs tested in 1984-85 were found to be HIV-antibody-positive. After 1988, 1% were estimated to seroconvert each year. While in the first phase the heroin users predominated among those infected, in later years the rates of newly diagnosed infections became similar for all types of IDUs. The age profiles of the IDUs tested were similar up to 1988, after which there was an indication that also younger persons had entered the scene. However, the infected IDUs discovered belonged mainly to the 'old' cohort born between 1950 and 1960.

A six-year follow-up of HIV seroprevalence among 300 intravenous drug users in Stockholm.

As HIV tests became available in 1984, 300 intravenous drug users (IVDUs) admitted to treatment centres in Stockholm were tested and asked questions regarding their drug use and other risk factors with regard to HIV. At this initial testing, 33 persons (11.0%) were seropositive. Among the 79 heroin users, 28 (35.4%) were positive. The cohort has been followed until 1990 at which time a further 12 seroconversions had taken place. Annual seroconversion rates fell during the study period. The findings support the official statistics showing a fall in new HIV diagnoses among IVDUs during the second half of the 1980's.