RESUMO
Parasites have the capacity to affect animal populations by modifying host survival, and it is increasingly recognized that infectious disease can negatively impact biodiversity. Populations of the house sparrow (Passer domesticus) have declined in many European towns and cities, but the causes of these declines remain unclear. We investigated associations between parasite infection and house sparrow demography across suburban London where sparrow abundance has declined by 71% since 1995. Plasmodium relictum infection was found at higher prevalences (averaging 74%) in suburban London house sparrows than previously recorded in any wild bird population in Northern Europe. Survival rates of juvenile and adult sparrows and population growth rate were negatively related to Plasmodium relictum infection intensity. Other parasites were much less prevalent and exhibited no relationship with sparrow survival and no negative relationship with population growth. Low rates of co-infection suggested sparrows were not immunocompromised. Our findings indicate that P. relictum infection may be influencing house sparrow population dynamics in suburban areas. The demographic sensitivity of the house sparrow to P. relictum infection in London might reflect a recent increase in exposure to this parasite.
RESUMO
OBJECTIVE/BACKGROUND: This study aims to compare differences in pain beliefs according to headache type, chronic vs episodic migraine, in a large cohort of patients, using the Pain Beliefs and Perceptions Inventory (PBPI), and to identify possible predictive factors of the same pain beliefs. METHODS: All patients referring for the first time at our center in 2011 were screened using PBPI and the Hamilton Anxiety and Depression Scale (a total of 1032 patients). PBPI is a 4-subscale questionnaire that explores a patient's personal beliefs on their subjective experience of pain. Headache patients also completed the Headache Impact Test (HIT-6) and a 30-day headache diary. For all participants, age, gender, duration of pain were collected. The sample was narrowed down to 899 as we experienced a nonresponse rate of 12.8%. For the purpose of this study, 2 groups were identified: chronic and episodic migraine, consisting of 116 and 126 patients, respectively, which were compared using Student's t-test; correlation analyses were conducted to investigate the relationship between variables before running a model selection based on Akaike's Information Criterion to identify possible predictive factors of different pain beliefs. Patients below 18 years of age and those diagnosed with other painful conditions were excluded from the analysis. RESULTS: Beliefs from chronic and episodic migraine patients were very similar, with only a difference in beliefs related to constancy of pain (Mean value ± SD 0.5 ± 1.1 vs -0.6 ± 1.1, P<.001). Predictive factors were depression and HIT-6 scores for all PBPI subscales apart from Self-Blame, which showed a stronger relation to anxiety scores. Number of days with headache per month was correlated to higher constancy values. Diagnosis was a predictive factor for any particular belief. DISCUSSION: This is the first study, to our knowledge, that addresses differences and predictive factors in pain beliefs according to headache diagnosis. A deeper knowledge of beliefs pattern in patients could lead to better-tailored psychological management.
