Water-quality and ecosystem impacts of recreation in streams: Monitoring and management

There is limited published information on the impact of bathing on stream water quality and ecology, except on human pathogens and health. We investigated the relationships between environmental quality of streams and recreational activity at five sites in the Australian Wet Tropics. The streams normally had very low concentrations of nutrients and suspended solids (TSS), but concentrations fluctuated widely during spates, thereby causing difficulties in discriminating impacts. Daily bathing activity disturbed sediments causing an increase in TSS and turbidity, which greatly exceeded national guidelines for maintenance of aesthetic qualities. TSS returned to background levels overnight as bathing areas were flushed clean. Total nitrogen and phosphate concentrations also increased with bather numbers, and phosphate concentrations were directly proportional to bather density. Faecal coliform concentrations were elevated by bathers at one site. Ecological effects of bathers were equivocal and greater on algal than invertebrate assemblages. Water quality degradation, although transient, suggested that some sites were close to their carrying capacity for bathers. Our results show that water quality may vary with local conditions and that cost-effective monitoring and management require development of cause-effect models of water quality processes for each stream site

Enhancing whole-of-river conservation

We argue for improved conservation of freshwater ecosystems at catchment or eco-regional scales by explicit assignment of values to all river sections and wetlands, recognising current disturbance, and aiming for ‘no further harm’ to the commons. The need is indicated by the global deterioration of biodiversity and ecosystem services of rivers and wetlands, increasing demands on water and land resources, and climate change. Regional pressures include multiple jurisdictions, competing demands, piecemeal management, pollution and habitat impacts. Effective resource and conservation management needs to integrate multiple uses via governance of activities of stakeholders, recognising hydrogeomorphic, water quality and ecological properties of ecosystems. Complete ecological protection is impractical amidst water-resource and land-use development, but we suggest that all river reaches and wetlands be given a conservation rating based on habitat, biodiversity and connectivity values. We present a straightforward approach to spatial conservation rating of freshwaters, using hydrogeomorphic typology and assignment of conservation values on the basis of available information and expert elicitation. We illustrate the approach by using the large Burdekin River catchment in north-eastern Australia. This approach is complementary to more spatially focused conservation prioritisation and could greatly improve management for sustainability, reduce further decline in conservation values, and facilitate rehabilitation

Species interactions in a parasite community drive infection risk in a wildlife population

Most hosts, including humans, are simultaneously or sequentially infected with several parasites. A key question is whether patterns of coinfection arise because infection by one parasite species affects susceptibility to others or because of inherent differences between hosts. We used time-series data from individual hosts in natural populations to analyze patterns of infection risk for a microparasite community, detecting large positive and negative effects of other infections. Patterns remain once variations in host susceptibility and exposure are accounted for. Indeed, effects are typically of greater magnitude, and explain more variation in infection risk, than the effects associated with host and environmental factors more commonly considered in disease studies. We highlight the danger of mistaken inference when considering parasite species in isolation rather than parasite communities.Fil: Telfer, Sandra. University Of Aberdeeen; Reino UnidoFil: Lambin, Xavier. University of Aberdeen; Reino UnidoFil: Birtles, Richard. University of Liverpool; Reino UnidoFil: Beldomenico, Pablo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Burthe, Sarah. Uk Centre For Ecology &Fil: Paterson, Steve. University of Liverpool; Reino UnidoFil: Begon, Mike. University of Liverpool; Reino Unid

Rickettsia mongolotimonae Infection in South Africa

We report the first laboratory-confirmed case of Rickettsia mongolotimonae infection in Africa. The patient sought treatment for an eschar on his toe; lymphangitis, severe headaches, and fever subsequently developed. After a regimen of doxycycline, symptoms rapidly resolved. R. mongolotimonae infection was diagnosed retrospectively by serologic tests and molecular-based detection of the organism in biopsy specimens of eschar material

A prospective study of cat-scratch disease in Lima-Peru

Cat-Scratch Disease (CSD) is a benign lymphadenitis that may progress to severe or recurrent forms, and it is occasionally associated with morbidity. Between January of 1998 and March of 1999, forty-three suspected CSD patients were assessed in the Hospital Cayetano Heredia and the Instituto de Salud del Niño, in Lima, Peru. Twelve patients had a confirmed diagnosis, 8 of whom were women, and the mean age was 10 years old. The majority (53%) of the cases were encountered in the summer. All patients reported having had contact with cats. Fever, malaise, lymphadenopathy and skin lesions were the most frequent clinical features. Twelve patients had indirect immunofluorescence antibody test titers of between 1/50 and 1/800 for Bartonella henselae and Bartonella clarridgeiae. Two lymph node biopsies were histologically compatible with CSD. No positive blood cultures could be obtained. This is the first Peruvian prospective study able to identify B. henselae and B. clarridgeiae in pediatric patients.A doença da arranhadura do gato é descrita como uma linfadenite benigna que pode progredir para formas recorrentes ou severas, sendo isto ocassionalmente associado com morbidade. Entre janeiro de 1998 e março de 1999, 43 pacientes foram admitidos no Hospital Cayetano Heredia e no Instituto de Salud del Niño, em Lima -Peru. Doze pacientes tiveram o diagnóstico confirmado, sendo 8 mulheres, com uma média de idade de 10 anos. A maioria (53,3%) dos casos foram recrutados no verão. Todos os pacientes relataram ter contato com gatos. Febre, mal-estar, linfadenopatia e lesões cutâneas foram as características mais freqüentes. Doze pacientes tiveram títulos de imunofluorescência indireta (IFI) entre 1/50 e 1/800 para Bartonella henselae e Bartonella clarridgeiae. Duas biópsias de linfonodos foram descritas como típicas para doença da arranhadura do gato. Nenhuma hemocultura se mostrou positiva. Este é o primeiro estudo peruano prospectivo que foi capaz de identificar Bartonella henselae e Bartonella clarridgeiae em pacientes pediátricos

Strategies of exploitation of mammalian reservoirs by Bartonella species

Numerous mammal species, including domestic and wild animals such as ruminants, dogs, cats and rodents, as well as humans, serve as reservoir hosts for various Bartonella species. Some of those species that exploit non-human mammals as reservoir hosts have zoonotic potential. Our understanding of interactions between bartonellae and reservoir hosts has been greatly improved by the development of animal models for infection and the use of molecular tools allowing large scale mutagenesis of Bartonella species. By reviewing and combining the results of these and other approaches we can obtain a comprehensive insight into the molecular interactions that underlie the exploitation of reservoir hosts by Bartonella species, particularly the well-studied interactions with vascular endothelial cells and erythrocytes

Ixodes ricinus is not an epidemiologically relevant vector of Bartonella species in the wood mouse (Apodemus sylvaticus)

Bartonella are hemoparasites exploiting a range of mammals as reservoir hosts. Several species are zoonotic pathogens. Fleas, lice, and other arthropods, such as ticks, have been implicated as vectors. While the competence of ticks as vectors of Bartonella species has recently been demonstrated, the epidemiological significance of ticks as vectors of Bartonella species in wildlife populations remains unknown. We used the presence of deer at study sites to control the presence of Ixodes ricinus ticks, and used this system to determine whether I. ricinus contributes to the epidemiology of Bartonella species infections in small mammals. Ticks were present at all sites with deer, but were absent from all sites without deer; however, the abundance of ticks on small mammals did not affect the probability of wood mice being infected with Bartonella species. Data presented here indicate that I. ricinus is not involved in the transmission of Bartonella in woodland rodents.A. Harrison was supported by a Ph.D. studentship from the Department of Agriculture and Rural Development (DARD).http://www.liebertpub.com/publication.aspx?pub_id=67ab201