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Summary: 45 red foxes (Vulpes vulpes) from various regions of Latvia were examined by necropsy between 2003 and 2008 for the presence and infection intensity of Echinococcus multilocularis. The overall prevalence was 35.6 %, with the intensity of infection ranging from 1 to 1438. Although a limited number of foxes were examined, the prevalence was high and infected animals were found throughout the country. Considering the increasing number of humans infected with echinococcosis in Latvia since 2002, the situation is highly suggestive of a recent emergence of E. multilocularis. DNA sequences of four fox isolates were examined by multilocus analysis of mitochondrial and nuclear genes (cox1, nad1, rrnS, atp6, actII). All isolates were allocated to the predominant genetic form in Europe, with partial affinity of one isolate to a genotype that had previously been reported from southern Germany.

Fox baits containing 50 mg praziquantel were distributed by aircraft in a 3000 km2area of southwestern Germany from 1995 to 1999. 20 baits / km2were initially distributed at intervals of six to twelve weeks. Starting from a prebaiting prevalence of 64 % (95 % C.I. 59–69), a level of 15 % (C.I. 10–21) was reached after 18 months. Further decreasing the frequency and discontinuing the bait distribution caused a surge to 55 % (C.I. 49–61) within 36 months. Other cestode species (Taeniaspp., Mesocestoidesspp.) showed similar responses, while the prevalence of ascarid nematodes did not decline during baiting. New infections of fox cubs with E. multilocularis, but not with other cestodes, drastically decreased after one year. Prevalences of fox helminths in an external control area remained stable. Our data suggest that repeated praziquantel treatment of free ranging foxes is suitable to reduce the prevalence of E. multilocularisin a large area.

A survey on the prevalence of Echinococcus multilocularis in foxes was conducted in the administrative district of Starnberg (federal state of Bavaria, Germany) and some adjacent municipalities from October 2002 to March 2003. The background to the study was the scarcity of recent data for Bavaria, where, in contrast to neighbouring regions, a general increase in the prevalence of the parasite has not yet been demonstrated. To estimate the current infection rate, a total of 268 shot foxes were examined using the intestinal scraping technique, resulting in an overall prevalence of 51%. This was compared with retrospective data collected during the period from 1989 to 2001. For the corresponding area and season, the retrospective prevalence was estimated at 32%, based on 222 shot foxes. The prevalence and its temporal development differ considerably on small spatial scales. The most conspicuous change has taken place in the western part of the study area, where a previous prevalence of 35% has increased to 80% in 2002/2003.

Following a brief introduction of recent advances in molecular and immunological technology for detection of persons and animals infected with Echinococcus multilocularis and an overview of the current situation of alveolar echinococcosis (AE) in Japan, perspectives on control options are discussed with reference to different epidemiological situations. AE is considered the most serious parasitic zoonosis in temperate and arctic regions of the northern hemisphere. The number of human cases differs drastically among regions. While high numbers of patients are apparently associated with high E. multilocularis prevalence in domestic dogs, e.g. in parts of Alaska and western China, the number of cases is moderate or low in areas where the parasite is mainly transmitted by wild canid species (e.g. in central Europe or temperate North America). However, the severity of the disease, the absence of curative treatment for most cases, the high cost of long-term chemotherapy and the anxiety caused for the population in highly endemic areas call for the development of preventive strategies even in regions where human AE is rare. Furthermore, in view of (1) drastically increasing numbers and infection rates of foxes involved in transmission of E. multilocularis, and (2) increasingly close contact between humans and foxes e.g. in Europe and Japan, there is considerable concern that AE incidences may in future increase in these regions. Control options depend on a variety of factors including the species of canid principally responsible for transmission and the socio-economic situation in the region. Where domestic dogs (stray or owned) are the principal hosts for E. multilocularis, control options can include those applicable to E. granulosus, i.e. reduction of the number of stray dogs, registration and regular preventive chemotherapy of owned dogs, and information campaigns for the population promoting low-risk behaviour for man and dogs. Where E. multilocularis is mainly transmitted by wild canids, the situation is far more difficult with preventive strategies still being in trial stage. Integrated control measures could include prevention information campaigns, restricting access of pet animals (dogs and cats) to rodents, chemotherapy of foxes on local or regional scales, and strategies to minimize contacts between people and foxes.

In 1982-1984, an epidemiologic survey of the prevalence of hepatitis B virus surface antigen (HBsAg) in circulating blood (HBs-antigenemia) and of hepatitis delta virus infection was performed in Kenya. The distributions of hepatitis B virus and the delta virus were shown to be very variable. In southern Kenya, only two of 202 sera from HBsAg-positive individuals with no known liver disease and none from 123 HBsAg-positive patients with hepatitis B-related liver disease were positive for delta antibody. In contrast, in northern Kenya, there was an overall prevalence of delta antibody in healthy individuals of 31%. The distribution of delta infection is discussed in relation to lifestyle, ethnic group, and geographic area.

3553 nomads in Turkana, a remote area of north-west Kenya, were screened for hydatid cysts by a portable ultrasound scanner and by serology. 198 (5·6%) proved to have liver or upper abdominal cysts. In the group screened by both techniques (2644) 174 (6·6%) cases of hydatidosis were detected by ultrasonography and 76 (2·9%) by serology. Ultrasonography gave immediate results and was less expensive and more acceptable and educationally valuable to the people. This non-invasive rapid technique also provided important clinical information about the cysts. The prevalence data thus obtained will contribute to the surveillance of a hydatid control programme.

Oral uptake of infectious Echinococcus multiloculariseggs shed by canids with their faeces may lead to development of alveolar echinococcosis in humans, which is clinically similar to a malignant infiltrative tumor and may be fatal if left untreated. E. multilocularisis therefore regarded as one of the most important and neglected metazoan parasites in the Northern hemisphere. The diagnosis of this tapeworm in the final host plays a key role in the epidemiology of E. multilocularis.