Incidence of Pneumocystis jiroveci Pneumonia among Groups at Risk in HIV-negative Patients

International audienceBackground - Pneumocystis jiroveci pneumonia in human immunodeficiency virus (HIV)-negative immunocompromised patients is associated with high mortality rates. Although trimethoprim-sulfamethoxazole provides a very effective prophylaxis, pneumocystosis still occurs and may even be emerging due to suboptimal characterization of patients most at risk, hence precluding targeted prophylaxis. Methods - We retrospectively analyzed all cases of documented pneumocystosis in HIV-negative patients admitted in our institution, a referral center in the area, from January 1990 to June 2010, and extracted data on their underlying condition(s). To estimate incidence rates within each condition, we estimated the number of patients followed-up in our area for each condition by measuring the number of patients admitted with the corresponding international classification diagnostic code, through the national hospital discharge database (Program of Medicalization of the Information System [PMSI]). Results - From 1990 to 2010, 293 cases of pneumocystosis were documented, of which 154 (52.6%) tested negative for HIV. The main underlying conditions were hematological malignancies (32.5%), solid tumors (18.2%), inflammatory diseases (14.9%), solid organ transplant (12.3%), and vasculitis (9.7%). Estimated incidence rates could be ranked in 3 categories: 1) high risk (incidence rates >45 cases per 100,000 patient-year): polyarteritis nodosa, granulomatosis with polyangiitis, polymyositis/dermatopolymyositis, acute leukemia, chronic lymphocytic leukemia, and non-Hodgkin lymphoma; 2) intermediate risk (25-45 cases per 100,000 patient-year): Waldenström macroglobulinemia, multiple myeloma, and central nervous system cancer; and 3) low risk (<25 cases per 100,000 patient-year): other solid tumors, inflammatory diseases, and Hodgkin lymphoma. Conclusions - These estimates may be used as a guide to better target pneumocystosis prophylaxis in the groups most at risk

Could Work Be a Source of Behavioural Disorders? A Study in Horses

Stress at work, as shown by a number of human studies, may lead to a variety of negative and durable effects, such as impaired psychological functioning (anxiety, depression…). Horses share with humans this characteristic of working on a daily basis and are submitted then to work stressors related to physical constraints and/or more “psychological” conflicts, such as potential controversial orders from the riders or the requirement to suppress emotions. On another hand, horses may perform abnormal repetitive behaviour (“stereotypies”) in response to adverse life conditions. In the present study, we investigated whether the type of work the horses are used for may have an impact on their tendency to show stereotypic behaviour (and its type) outside work. Observations in their box of 76 horses all living in the same conditions, belonging to one breed and one sex, revealed that the prevalence and types of stereotypies performed strongly depended upon the type of work they were used for. The stereotypies observed involved mostly mouth movements and head tossing/nodding. Work constraints probably added to unfavourable living conditions, favouring the emergence of chronic abnormal behaviours. This is especially remarkable as the 23 hours spent in the box were influenced by the one hour work performed every day. To our knowledge, this is the first evidence of potential effects of work stressors on the emergence of abnormal behaviours in an animal species. It raises an important line of thought on the chronic impact of the work situation on the daily life of individuals

How horses (Equus caballus) see the world: humans as significant objects

International audienceThe aim of this study was to determine whether horses have a kind of memory of humans(based on previous interactions), leading to a general significance of humans revealed by theirreactions to humans in subsequent interactions. This hypothesis was tested on 59 adultanimals (coming from 3 riding schools with similar life conditions) using three types ofbehavioural tests, which involved an unknown experimenter and corresponded to threepotential memories of the relation (not work-related, using work-related objects, unfamiliarworking task). To get a broad overview of the horses’ reactions to humans, we recorded bothinvestigative and aggressive behaviours during the tests, representing respectively a “positive”and a “negative” memory of the relationship. It appeared that while correlations between testsrevealed a general perception of humans as positive or negative, unusual tests, i.e. that are notusually performed, elicited more positive reactions. Thus, some horses reacted positively to amotionless person in their box, but negatively when this same person approached them, forexample with a halter. In overall, aggressive reactions to the experimenter were more reliableindicators of the relationship than positive reactions. Altogether, the results support thecreation of a memory of humans by horses which impacts their reactions in subsequentinteractions

Altered welfare is linked with aggressiveness in horses

International audienceBehavioural problems in horses, in particular aggressions towards humans, are a common source of accidents in professionals (e.g. the third after dogs and bovid in veterinarians). Temperamental traits and experienceinduced aspects are commonly mentioned when evaluating horses’ reactions to humans. However, fewer studies focused on the relation between horses’ welfare and their undesirable reactions towards humans. Yet there are some recent elements suggesting that an altered welfare (from a chronic discomfort to a painful experience) could affect animals’ relational behaviour. In the present study, we hypothesized that part of the aggressiveness towards humans in horses may be linked with altered welfare. Thus, fifty nine horses from 3 riding centres were submitted to five standardized behavioural tests in order to evaluate their reactions to humans (a motionless person test, an approach-contact test, a sudden approach test with or without a saddle on the arm and halter fitting test). At the same time, a large set of potentially welfare-related indicators were recorded: health-related (e.g. vertebral problems…), postural (e.g. ears positions at rest…), physiological (e.g. stress hormones…) and behavioural (e.g. behavioural repertoire…) indicators. It appeared that about half (51%) of the horses showed at least once an aggressive reaction towards the experimenter. Interestingly, these aggressive horses displayed a characteristic ears laid back posture (Mann Whitney tests, P<0.05), were statistically more prone to suffer from vertebral problems (binomial tests, P<0.05) and had higher level of plasmatic cortisol rate (Mann Whitney tests, P<0.05). These promising results confirm a possible relation between altered welfare and part of the undesirable reactions towards humans in horses (here aggressiveness). Moreover, some of the indicators used are easy to record (e.g. ears positions at rest) and could be used to identify aggressive horses and consequently improve safety

Animal behaviour and human safety: Identifying “at risk” situations in human-horse interactions

International audienc

Human/horse relationship quality : a same perception of humans for horses reflected in different situations

International audienceHuman-horse relationship (HHR) is of major importance in both competition as well as recreational horseback riding. A negative perception of humans by horses can decrease performances, welfare of both horse and rider and safety for both parties. Several behavioural tests have been used to evaluate HHR but no study compare horses’ reactions between these tests. This study aimed to investigate if horses generalize their reactions to humans from one to another context or if HHR quality depends on context assessment. Four tests were performed on 60 horses in riding centres including (a) ‘passive presence test’ (the experimenter entered the box and remained motionless during 5 minutes), (b) ‘slow approach test’ (the experimenter approached slowly and tried to touch the horse in the box), (c) ‘saddle-approach test’ (experimenter showing a saddle to the horse) and (d) ‘bridge test’ (the experimenter led the horse and tried to make it cross a mattress). The behaviour of the horse, and the time required by the horse to accept being touched and the time required for the horse to cross the bridge were recorded. Non-parametric analyses were performed to compare the horses’ reactions between all tests. The horses that were the most difficult to touch in their box also stayed the furthest away from the motionless human (Spearman, ρ = -0.41, p = 0.002), were the most aggressive when approached with a saddle (Fisher, p = 0.01) and were the most reluctant to cross the bridge (MannWhitney, U = 74, p = 0.002). Similarly, the most agressive horses when approached with a saddle were also the most reluctant to cross the bridge (Fisher, p = 0.04) and the most threatening towards the motionless human (MannWhitney, U = 169, p = 0.007). The findings suggest that an altered HHR may be reflected in different contexts and daily perception of humans may present as stressful for these horses, potentially leading to poor welfare, performances and safety in some instances

Human-horse relationship quality: a same perception of humans for horses reflected in different situations

International audienceHuman-horse relationship (HHR) is of major importance in both competition as well as recreational horseback riding. A negative perception of humans by horses can decrease performances, welfare of both horse and rider and safety for both parties. Several behavioural tests have been used to evaluate HHR but no study compare horses’ reactions between these tests. This study aimed to investigate if horses generalize their reactions to humans from one to another context or if HHR quality depends on context assessment. Four tests were performed on 60 horses in riding centres including (a) ‘passive presence test’ (the experimenter entered the box and remained motionless during 5 minutes), (b) ‘slow approach test’ (the experimenter approached slowly and tried to touch the horse in the box), (c) ‘saddle-approach test’ (experimenter showing a saddle to the horse) and (d) ‘bridge test’ (the experimenter led the horse and tried to make it cross a mattress). The behaviour of the horse, and the time required by the horse to accept being touched and the time required for the horse to cross the bridge were recorded. Non-parametric analyses were performed to compare the horses’ reactions between all tests. The horses that were the most difficult to touch in their box also stayed the furthest away from the motionless human (Spearman, ρ = -0.41, p = 0.002), were the most aggressive when approached with a saddle (Fisher, p = 0.01) and were the most reluctant to cross the bridge (MannWhitney, U = 74, p = 0.002). Similarly, the most agressive horses when approached with a saddle were also the most reluctant to cross the bridge (Fisher, p = 0.04) and the most threatening towards the motionless human (MannWhitney, U = 169, p = 0.007). The findings suggest that an altered HHR may be reflected in different contexts and daily perception of humans may present as stressful for these horses, potentially leading to poor welfare, performances and safety in some instances

Human/horse relationship quality: an overall ‘meaning’ for horses reflected in different situations

International audienc

Indicateurs de bien-être/mal-être chez le cheval : une synthèse

National audienc

How horses (Equus caballus) see the world: humans as significant "objects"

WOS:000267205800010International audienceThis study aimed to determine whether horses have a kind of memory of humans (based on previous interactions), leading to a general significance of humans revealed by their reactions to humans in subsequent interactions. Subjects were 59 adult horses used to interact daily with humans. Three types of behavioural tests involving an unknown experimenter evaluated three possibly different memorized types of human-animal interactions (not work-related, using work-related objects, unfamiliar working task). We also performed standardized observations of routine interactions between each horse and its familiar handler (caretaker). To get a broad overview of the horses' reactions to humans, we recorded both investigative and aggressive behaviours during the tests, representing respectively a "positive" and a "negative" memory of the relationship. Whereas correlations between tests revealed a general perception of humans as either positive or negative, unusual tests, i.e. that are not usually performed, elicited more positive reactions. Moreover, some horses reacted positively to a motionless person in their box, but negatively when this same person approached them, for example for halter fitting. Overall, aggressive reactions were more reliable indicators of the relationship than positive reactions, both between tests and between familiar and unfamiliar humans. Our results also show generalization of the perception of humans. These results support our hypothesis that perception of humans by horses may be based on experience, i.e. repeated interactions. Altogether, our results support the hypothesis that horses can form a memory of humans that impacts their reactions in subsequent interactions