Emergence of tick-borne encephalitis in new endemic areas in Austria: 42 years of surveillance

Human infections with tick-borne encephalitis (TBE)virus are a public health concern in certain regions of Europe, central and eastern Asia. Expansions of endemic areas and increased incidences have been associated with different factors including ecological changes supporting tick reproduction, socioeconomic changes increasing human outdoor activities and climatic changes favouring virus circulation in natural foci. Austria is among the most strongly affected countries in Central Europe, but the annual number of cases has strongly declined due to vaccination. Here,we have analysed changes of the incidence of TBE in the unvaccinated population of all federal states of Austria over a period of 42 years. The overall incidence in Austria has remained constant, but new strongly affected endemic regions have emerged in alpine valleys in the west of Austria. In parallel, the incidence in low-land regions in the north-east of the country is decreasing. There is no evidence for a shift to higher altitudes of infection sites in the traditional TBE zones,but the average altitudes of some newly established endemic areas in the west are significantly higher. Our analyses underscore the focal nature of TBE endemic areas and the potential of TBE virus to emerge in previously unaffected regions.

Transmission ofCampylobacterspp. in a poultry slaughterhouse and genetic characterisation of the isolates by pulsed-field gel electrophoresis

1. Contamination of retail products with Campylobacter spp. during the slaughter of poultry is a well-known problem of product hygiene. Mechanical evisceration often leads to intestinal rupture and discharge of gut contents, which can contain zoonotic and human pathogens. Processes along the slaughter line cause aerosols and airborne droplets, containing bacterial loads. 2. To estimate the possible transmission routes of intestinal Campylobacter, 36 measurements of the bioaerosol (Andersen sampler and SKC BioSampler), 30 cloacal (of three flocks), 10 equipment and 4 sedimentation samples were tested for the presence of Campylobacter species. 3. The results imply that, in addition to contaminated equipment, which was Campylobacter-positive in 80% of cases, aerosols with peak values of 4.0 x 10(4) (test series 1) and 1.4 x 10(4) (test series 2) CFU/m3 also provide a potential vector for horizontal transmission. 4. To explore the genetic similarities of isolates from different origins, 18 isolates recovered from air, 26 cloacal, 8 equipment and 4 sedimentation isolates were analysed by pulsed-field gel electrophoresis (PFGE), using the restriction enzymes Sma I and Sal I. The similarity of cloacal isolates with isolates from equipment, air and sediment, suggest that the contamination is of intestinal origin. 5. There were direct links between Campylobacter-positive flocks and the presence of the same strains in the aerosol of the slaughter hall. Air as a potential source for microbial transmission must be taken into account.

Quality of water--quality of life

Especially in developing countries, the problem of adequate drinking water supply is an ever growing one. Public health programmes have been established to improve the population's health conditions, but these programmes require big financial means for guaranteeing adequate supply of potable water and medical therapy for sick people. Too little emphasis is still put on regular testing of drinking water for microorganisms such as Aeromonas sp. and Vibrio sp. In a spot check analysis in various countries, the importance of Aeromonas sp. is shown--not a single sample complied with international norms and guidelines for drinking water.

Francisella tularensis in Dermacentor reticulatus ticks from the Czech Republic and Austria

Host-seeking adult Dermacentor reticulatus ticks were examined for the prevalence of Francisella tularensis in an active natural focus of tularemia along the lower reaches of the Dyje (Thaya) river in South Moravia (Czech Republic) and adjacent Lower Austria, in four localities of the flood plain forest-meadow ecosystem during the spring of 1996. The ticks were pooled (10 male or female ticks per group) and inoculated subcutaneously in 4-week-old SPF mice. Dead mice were sectioned, the spleens were homogenized in PBS and passaged in mice, and impression smears from the spleens, liver and heart blood were stained by Giemsa. Twenty-five isolates of F. tularenis were recovered from 1098 pooled D. reticulatus: the minimum infection rate (MIR) is 2.3%. MIRs for 629 female and 469 male D. reticulatus were 2.4% and 2.1%, respectively. The prevalence varied according to locality, but did not significantly differ between the Moravian (2.2%) and Austrian (2.8%) sites. The monitoring of D. reticulatus for F. tularensis might be a valuable contribution to the surveillance of tularemia in Europe.

Prevalence of Francisella tularensis in Dermacentor reticulatus ticks collected in adjacent areas of the Czech and Austrian Republics

A total of 1098 host-seeking adult Dermacentor reticulatus ticks were examined in an active enzootic focus (floodplain meadow and forest ecosystem) of tularemia along the lower reaches of the Thaya (Dyje) river in South Moravia (Czech Republic) and adjacent Austria during the spring of 1996. Twenty-five isolates of Francisella tularensis were recovered (i.e., the overall minimum infection rate was 2.3%). The prevalence rate varied between 0.6% and 3.5% among four localities examined (two in Moravia and two in Austria) but the difference in the rate between Moravia (2.2%) and Austria (2.8%) has not been significant. The results show that D. reticulatus plays the role of an important vector in this extensive, perennial natural focus of tularemia.

Campylobacter spp. and Salmonella spp. in black-headed gulls (Larus ridibundus)

Cloacal examination of 41 juvenile black-headed gulls (Larus ridibundus) by cultivation demonstrated Campylobacter jejuni in 26 (63%) and Salmonella typhimurium in 21 (51%) of them. All the bird samples were collected in a breeding colony near the town Hodonin, South Moravia, Czech Republic in 1996. Twenty six Campylobacter isolates were tested for antibiotic and drug sensitivity: all were resistant to at least three agents (Penicillin, Tetracyclin and Sulfomethoxazol-trimethoprim) while all were sensitive to Augmentan, Cefotaxim, Ciprofloxacin, Erythromycin, Nitrofurantoin and Cephazidine. Four percent of isolates were resistant to Ampicillin and Nalidixic acid. Of the 21 S. typhimurium isolates tested, 33% were sensitive to all drugs assayed, proportions of the strains resistant to Sulfomethoxazol-trimethoprim, Tetracyclin and Streptomycin were 58%, 16% and 8%, respectively.

Serological examination of human and animal sera from six countries of three continents for the presence of rickettsial antibodies

Forty samples each of human sera collected in Guinea Bissau, Cape Verde, El Salvador and Iran, and animal sera (goat and cattle from Sri Lanka and sheep from Tanzania) were examined for the presence of antibodies to typhus group (TG) rickettsiae, spotted fever group (SFG) rickettsiae and Coxiella burnetii by enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody (IFA) test. Of human sera tested, a higher proportion of positive sera were found with ELISA and IFA test for TG, SFG rickettsiae and C. burnetii in El Salvador (42.5 vs 20.0%, 40.0 vs 32.5%, and 27.5 vs 27.5%, respectively) and in Iran (25.0 vs 15.0%, 45.0 vs 27.5%, and 27.5 vs 25.0%, respectively), than in Guinea Bissau and Cape Verde, where they were less than 20.0% except for antibodies to SFG rickettsiae in Guinea Bissau (25.0% with ELISA and 20.0% with IFA test). While all animal sera were negative for the presence of antibodies to TG rickettsiae, a high proportion of sera from Sri Lanka reacted in ELISA and IFA test with SFG rickettsiae and C. burnetii (37.5 vs 20.0% and 27.5 vs 25.0% for goat sera, and 40.0 vs 30.0%, and 17.5 vs 15.0% for cattle sera, respectively). The results obtained indicate that the studied rickettsial diseases can be spread in given territories and may pose a public health problem requiring greater attention than has been paid so far. The suitability of ELISA and IFA test for serological survey of rickettsial antibodies is discussed.

People on the garbage dumps of Cairo: a toxicological in vivo model?

In the outskirts of Cairo, some 40,000 people live on garbage dumps. These people form a closed population whose socio-economic problems are identical. The pollutants are evenly distributed. Up to 30% of the garbage on the polluted area, which cannot be recycled, is burned, resulting in a high concentration of pollutants in the environment. The concentrations of heavy metals, dioxins/furans, PCB, PAH in dust deposit and soil were measured as well as the air pollutants SO2, HCl and CO. It was shown that while the systemic immune system is only affected to a very small degree, secretory immunoglobulin A is strongly affected by the emissions. It could be demonstrated also an increased readiness for allergic respiratory disease, through the proof of hyperreactive mucous membranes. In the polluted area, 58% of the examined children were affected, whereas in the control area only 22% displayed a hyperreactive mucous membrane. Also the concentration of NANA (N-acetyl-N-neuraminic acid) in the serum, as a unspecific marker of cell irritation, was high in the serum of children from the polluted area. Most of the pollutants detected can also be observed in the industrialized regions, especially in combination with incinerating plants. In this way, this study suggests the synergistic effects of pollutants.

Salmonellae in gulls and other free-living birds in the Czech Republic

Cloacal swabs, collected from 756 wild synanthropic and exoanthropic birds of 57 species in the Czech Republic, yielded 32 strains of Salmonella typhimurium [phage types (PT) 141, 104 and 41], six isolates of S. enteritidis (PT 8, 4 and 6e), and one each of S. panama and S. anatum. Except for one S. enteritidis isolate from a grey-lag goose (Anser anser) and one S. typhimurium isolate from a coot (Fulica atra), all of the other strains were derived from black-headed gulls (Larus ridibundus), of which 24.7% were found to be infected. The black-headed gull might play a role in the dispersal of pathogenic salmonellae.

Tick-borne encephalitis virus activity in Styria, Austria

From 3,404 Ixodes ricinus ticks collected in 12 localities of Styria, Austria in 1990, 15 tick-borne encephalitis (TBE) virus isolates were recovered. Minimal field infection rate reached 4.4 virus containing ticks out of 1,000 collected ticks. Five isolates of TBE virus were obtained from target organs of Apodemus flavicollis trapped in locality Wagnitz. In a serosurvey based on virus neutralizing antibodies high prevalence of TBE virus was demonstrated in A. flavicollis (47.9%) and Clethrionomys glareolus (29.4%). These rodents formed 57.8% and 41.0% of 83 trapped small mammals.

Cryptosporidiosis in children in Idukki District in southern India

Concentrated stool samples from 560 children, aged from two weeks to 10 years, from Idukki District, southern India, were examined to detect Cryptosporidium oocysts, using a phenol-auramin stain and fluorescent microscopy. Smears of stool samples were also stained by a modified Ziehl-Neelsen method and were examined by light-microscopy. One sample was collected from each of 266 children with diarrhoea and 294 age-matched children without diarrhoea. Cryptosporidium oocysts were detected in 4.5% of all stools, in 6% of diarrhoeal stools and in 3% of stools from healthy controls. Results of the study show that Cryptosporidium infection is common in children with diarrhoea in southern India, and there is also a high frequency of asymptomatic cyst-passers in this area.

[Air pollution emissions and changes in lung function]

Among the environmental hazards in a modern industrial society, air pollutants are of major significance. They can directly affect the cells of the bronchopulmonary system and lead to an irritation of the epithelial and immunocompetent cells. This results in a decreased secretion of immunoglobulin A, and, consequently, a decreased resistance against infections. Thereby pathogens, especially bacteria, may lead to an inflammation of the respiratory tract. Apart from the direct toxic effect of their pollutants, recurrent inflammations eventually lead to small airway obstruction. The spirometric parameters FVC, FEV1 and MEF50 were reduced. IgA concentration in the saliva was determined by means of immunodiffusion and was found to be reduced when compared to a less exposed group. A series of pathogenic germs were isolated from various mucous membranes (conjunctiva, nose/throat). The median immissions for the children examined were 1.345 mg/m3 SO2 and 0.189 mg/m3 HCl.

A survey of gastrointestinal parasites in Ogun State, southwest Nigeria

To study the epidemiology of intestinal parasites in Ogun State, Nigeria, 479 stool specimens were examined at a hospital in Abeokuta during the rainy season in June 1986. Intestinal helminths and/or protozoa were present in 297 samples (62%). 41.1% of the specimens showed a single infection, 34% showed double, 20% triple and 5% quadruple infection. The most commonly found worm was Ascaris lumbricoides (in 40% of specimens), followed by Trichuris trichiura (23.2%), hookworms (19.2%), Strongyloides stercoralis (2.1%) and Dicrocoelium sp. (0.4%). Pathogenic protozoa found were Entamoeba histolytica (7%), Giardia intestinalis (4.2%), Blastocystis hominis (2.5%) and Cryptosporidum sp. (2.3%). The apathogenic protozoa Entamoeba coli, Chilomastix mesnili, Trichomonas hominis and Iodamoeba buetschlii were also seen.

Cryptosporidiosis in Ogun State, south-west Nigeria

During the period of one month in the rainy season in Ogun State in south-west Nigeria 479 stool samples (420 of which were diarrhoea stool samples) were examined for cryptosporidiosis. Oocysts were detected in 2.3% of all stools, in 2.6% of diarrhoeal stools and in 5.3% out of 150 children with diarrhoea. Cryptosporidium was the sole pathogen detected in six of 11 cases. In addition to cryptosporidia also Entamoeba histolytica, Blastocystis hominis, Giardia lamblia, Ascaris lumbricoides, and Trichuris trichiura could be found. Compared to other studies in tropical countries, the frequency of infection was lower in south-west Nigeria.

Prevalence of arbovirus antibodies in sera of animals in Sri Lanka

The sera of cattle, goats, dogs and crows from the Colombo area were tested for antibodies against seven arboviruses of the families Togaviridae and Bunyaviridae by a plaque-reduction neutralization microtest, using Vero cells and a stable line of pig kidney (PS) cells. The overall percentages of positive sera among the mammals were: Bhanja, 92.5%; Calovo (Batai), 30.6%; Sindbis, 13.8%; Langat, 4.8%; Tahyna, 3.9%; West Nile, 1.6%. Among the birds, 23.8% had antibodies to Bhanja virus and 9.5% to Sindbis. No antibodies against tick-borne encephalitis virus were found. The results show that at least two members of the Bunyaviridae family (Bhanja and Calovo) are highly endemic in Colombo.

Isolation of influenza viruses from exotic and Central European birds

In the course of a study which was made in order to contribute to the knowledge about influenza viruses in birds, 18 strains of avian Influenza-A-subtypes were isolated from cloaca swabs. From the Central European bird species, one strain of Influenza A/England/62 was isolated from a mallard. All other species of birds obtained from three different biotopes from Austria and Hungary showed negative results. The other 17 influenza strains were isolated from imported birds from Senegal. Nine of these strains corresponded to subtype A/duck/England/62, five to subtype duck/England/56. One isolated strain showed a relation to A/duck/England/56 in terms of the hemagglutinin and to chicken/Brescia/1902 in terms of the neuraminidase. Two other strains reacted best with antisera against duck/England/62 in the hemagglutination inhibition test; the neuraminidase inhibition test showed a relation to subtype quail/Italy/65. The Newcastle disease-Virus was not isolated in any sample.

Helminths of the ploceid Textor cucullatus from Ghana

Two nematode species (Geopetitia sp. and Diplotriaena ozouxi) and an acanthocephalan (Mediorhynchus textori n. sp.) are described. The diplotriaenid has been recorded from a new host and also from a new locality. Because of homonymy of Geopetitia chaubaudi VUYLSTEKE, 1963 with Geopetitia chaubaudi RASHHED, 1960 a new name G. vuylstekei nom. nov. is proposed for the former species. Mediorhynchus textori is characterized by lesser number of rooted hooks arranged in spirals on theproboscis. The eggs of this species bear variable floats.

[Tests for anthropozoonoses in sera of farmers in eastern-Austria. I. Communication (author's transl)]

Because of human disease and the evidence of antibodies in domestic- and wild animal-sera, human sera were tested for various anthropozoonoses in three districts of the so called "Seewinkel" (Eastern-Austria). Positive reactions were found for listeriosis, tularemia, leptospirosis, ornithosis, Q-fever, rickettsiae of the RMSF-group "Stamm B", mycoplasmosis, TBE-(FSME-), Sindbis-, West Nil-VIRUS. These results are indicators for the occurrence of the pathogens and are supported by the positive results already found at serological tests of domestic and wild animals.