RESUMEN
The medically and veterinary important feral pigeon tick Argas reflexus (Ixodida: Argasidae) Fabricius usually feeds on pigeons, but if its natural hosts are not available, it also enters dwellings to bite humans that can possibly react with severe allergic reactions. Argas reflexus is ecologically extremely successful as a result of some outstanding morphological, physiological, and ethological features. Yet, it is still unknown how the pigeon tick finds its hosts. Here, different host stimuli such as living nestlings as well as begging calls, body heat, smell, host breath and tick faeces, were tested under controlled laboratory conditions. Of all stimuli tested, only heat played a role in host-finding. The heat stimulus was then tested under natural conditions within a pigeon loft. The results showed that A. reflexus is able to find a host over short distances of only a few centimetres. Furthermore, it finds its host by random movements and recognizes a host only right before direct contact is made. The findings are useful for the control of A. reflexus in infested apartments, both to diagnose an infestation and to perform a success monitoring after disinfestation.
Asunto(s)
Argas/fisiología , Enfermedades de las Aves/parasitología , Columbidae , Conducta de Búsqueda de Hospedador , Infestaciones por Garrapatas/veterinaria , Animales , Argas/crecimiento & desarrollo , Larva/crecimiento & desarrollo , Larva/fisiología , Infestaciones por Garrapatas/parasitologíaRESUMEN
Feral pigeons (Columba livia domestica), which thrive in most European towns and cities, are commonly infected with the zoonotic bacterium Chlamydophila psittaci, the agent of psittacosis (also known as ornithosis) in humans. A number of surveys carried out over the last thirty years across Europe have detected high seropositivity values and high percentages of infection in feral pigeon populations. Overall, when considering data from 11 European countries, seropositivity values to C. psittaci in the sampled populations ranged from 19.4% to 95.6%. In most surveys, the complement fixation test was used, and antibodies were detected in 19.4-66.3% of the samples, with a median of 46.1%. Indirect immunofluorescence and ELISA tests were employed less frequently, but led to the detection of higher percentages of seropositivity (23.7-67.7% and 35.9-95.6%, respectively). Attempts to grow C. psittaci in cell culture or embryonated chicken eggs were successful in 2-42.3% and 0-57.1% of samples, respectively, antigen detection methods were positive in 2.3-40% of samples, while conventional PCR and real-time PCR using different genomic targets detected the organism in 3.4-50% of samples. Twenty-five C. psittaci isolates from pigeons were typed as ompA genotype B (n=14), E (n=10) and E/B (n=1). The huge increase of feral pigeon populations in Europe is a major cause of concern for the detrimental effect of pigeon droppings on environmental hygiene, in addition to the extensive damage due to the fouling of buildings and monuments. The most important pathogenic organism transmissible from feral pigeons to humans is C. psittaci, with 101 cases of disease reported in the literature. Exposure to C. psittaci-contaminated dust, direct contact with pigeons through handling and, to a lesser extent, through pigeon feeding have been identified as hazardous exposures in more than half of the human cases, while loose or transient contacts with feral pigeons have been mentioned in about 40% of the cases. Education initiatives as to the communication of a health risk resulting from contact with pigeons and pigeon excreta should primarily be targeted at individuals who may be exposed to C. psittaci-contaminated dust, such as demolition/construction workers. Recommendations to this category of workers include wearing protective clothes with hoods, boots, gloves and air filter face masks when removing pigeon faeces from roofs, garrets and buildings, especially if working indoors. Monitoring for C. psittaci infections in these workers over time should also be considered. Children should be warned not to handle sick or dead pigeons, and immunocompromised individuals should be advised to carefully limit their contact to feral pigeons. Culling of pigeons by shooting or poisoning is both unethical and ineffective as the place of the killed birds in the population is quickly filled by new juveniles or immigrating birds from neighbouring areas. Pigeon-deterring systems, such as nets and plastic or metal spikes applied to buildings and monuments will prevent their fouling, and the administration of contraceptive drugs may allow size regulation of the pigeon populations. Nevertheless, the measure that will ultimately lead to permanent reduction and will establish healthy sustainable populations is the restriction of indiscriminate feeding by pigeon lovers. The erection of dovecotes and artificial breeding facilities should be considered for providing shelter and a balanced diet to the birds, as well as a chance of interaction for pigeon lovers in a hygienically controlled environment.
Asunto(s)
Enfermedades de las Aves/microbiología , Infecciones por Chlamydia/veterinaria , Columbidae , Salud Pública , Animales , Animales Salvajes , Enfermedades de las Aves/epidemiología , Infecciones por Chlamydia/epidemiología , Europa (Continente)/epidemiologíaRESUMEN
A comprehensive literature search of epidemiological studies and reports of transmissions of disease from feral pigeons to humans was performed. There were 176 documented transmissions of illness from feral pigeons to humans reported between 1941 and 2003. Feral pigeons harbored 60 different human pathogenic organisms, but only seven were transmitted to humans. Aerosol transmission accounted for 99.4% of incidents. There was a single report of transmission of Salmonella enterica serotype Kiambu to humans from feral pigeons, and no reports of transmission of Campylobacter spp. The most commonly transmitted pathogens continue to be Chlamydophila psittaci and Cryptococcus neoformans. Although feral pigeons pose sporadic health risks to humans, the risk is very low, even for humans involved in occupations that bring them into close contact with nesting sites. In sharp contrast, the immunocompromised patient may have a nearly 1000-fold greater risk of acquiring mycotic disease from feral pigeons and their excreta than does the general population.
Asunto(s)
Enfermedades de las Aves/microbiología , Enfermedades de las Aves/transmisión , Columbidae , Zoonosis/microbiología , Zoonosis/transmisión , Animales , Enfermedades de las Aves/epidemiología , Estudios Epidemiológicos , Heces/microbiología , Sustancias Peligrosas , Humanos , Huésped Inmunocomprometido , Estudios Retrospectivos , Población Urbana , Zoonosis/epidemiologíaRESUMEN
The relevance of using lucky charms in the examination room has not been well studied. In this analysis the frequency and results of using lucky charms have been determined in a group of medical students (n = 676) sitting the first examination in the medical curriculum (first propaedeutics). Approximately 10% of all candidates took lucky charms with them into the examination room. Lucky charms were worn significantly more often by female examinees than by males. However, examination results were not significantly better among charm wearers than those without. The commonest charms were in the form of ladybirds or pigs, most of the other 27 also being animal representations.
Asunto(s)
Evaluación Educacional , Estudiantes de Medicina/psicología , Supersticiones , Logro , Adulto , Biología/educación , Educación Médica , Femenino , Humanos , Masculino , SuizaRESUMEN
A Natural Phenomenon, Molestation or a Health Risk? For the last two decades an avenue in the centre of Basel (Altrheinweg, Klybeckquartier) is known as site for overnight accommodation and assembly of starlings (Sturnus vulgaris) during autumn. The nightly visitors cause an immense contamination that directly affects a nursery and a primary school. The aim of the present study was the evaluation of the health risk for the population due to the starlings' droppings, particularly for the children from the nursery school. Between August and December of the years 1995 and 1996 the population of starlings was observed, the contamination of the area with faeces was quantified, the presence of microorganisms in the faeces was determined and the contamination of the soil from the Altrheinweg was compared with that from other avenues and parks. Furthermore, the children attending the nursery school were monitored for possible infections due to the birds' droppings. In mid-October, when the population of starlings reached their maximum of about 15,000 birds, 1053 defecations per night and square metre were counted on an average in 1995 and 1821 in 1996. The microbiological analysis of the starlings' faeces showed a high contamination with Campylobacter spp. (1995: 95.5%; 1996: 100%), L. monocytogenes (1995: 36.5%; 1996: 26.7%) and C. psittaci (1995: 40.5%), a lower contamination with Salmonella spp. (1995: 1.0%), S. aureus (1995: 2.0%), Y. enterocolitica (1995: 1.5%) and Y. pseudotuberculosis (1995: 1.0%). Mycotic and parasitic human pathogens were not found. The contamination of the soil from the Altrheinweg with Campylobacter spp. and L. monocytogenes was significantly greater than that of the other avenues and parks in Basel. However, the investigations conducted by the school medical service showed that no infections among the children attending the nursery school could be correlated to the presence of the starlings. Even if the heavy contamination of the area with droppings of starlings presents a potential health risk, a continuous or systematic transmission of infectious agents seems rather improbable due to the contamination-avoiding behaviour of the children, the characteristics of the microorganisms involved and the climatic conditions in autumn. This situation showed however not reduce our awareness of such a potential health risk.
Asunto(s)
Aves , Monitoreo del Ambiente/estadística & datos numéricos , Contaminación Ambiental/estadística & datos numéricos , Salud Urbana , Zoonosis/microbiología , Animales , Aves/microbiología , Niño , Guarderías Infantiles , Preescolar , Heces/microbiología , Humanos , Microbiología del Suelo , SuizaRESUMEN
The feeding of animals as a friendly gesture is deeply rooted in man. This behaviour has a negative effect on the Street-pigeons which as a consequence suffer from overpopulation. The problem can only be solved by limiting this feeding. The pigeon-feeders are the cause of the pigeon-problem in our cities. The feeders can by their motivation be classified in various groups. Play-feeders and display-feeders can be recognised. They are more easily to be dealt with than the fanatical pigeon-friends who show a strong emotional attachment to these birds. The pigeon-problem can be overcome if this stubborn group can be taught to change his behaviour. Such a solution would be highly rewarding as great sums of money are spent to remove damages caused by the pigeons to buildings and works of art.
Asunto(s)
Alimentación Animal , Columbidae , Cultura , Conducta Social , Animales , Vínculo Humano-Animal , Humanos , Densidad de Población , Salud UrbanaRESUMEN
An ethometrical analysis of street pigeons showed that most social interactions under conditions of overpopulation are of an aggressive nature. Through various mechanisms this frequent aggressive behaviour leads to "slumlike" living conditions characterized by intraspecific stress. It is possible to characterize street pigeons in their urban environment by calculating the frequencies of the most important aggressive and sexually-motivated social interactions. Behavioral patterns adapted to their living conditions result in misbehaviour in an anthropogenous environment. A high population density in commercial pigeon units should therefore be avoided. It is also necessary to consider the typical disposition of a race for aggressive behaviour. The frequent aggressive interactions among street pigeons at their breeding lofts seem to play an important role as a density dependent regulator of population size.