Protection Generated by Prior Exposure to Pathogens Depends on both Priming and Challenge Dose.

Free-living hosts encounter pathogens at a wide range of frequencies and concentrations, including low doses that are largely aclinical, creating a varied landscape of exposure history and reinfection likelihood. While several studies show that higher priming doses result in stronger immunological protection against reinfection, it remains unknown how the reinfection challenge dose and priming dose interact to determine the likelihood and severity of reinfection. We manipulated both priming and challenge doses of Mycoplasma gallisepticum, which causes mycoplasmal conjunctivitis, in captive house finches (Haemorhous mexicanus), to assess reinfection probability and severity. We found a significant interaction between priming and challenge doses on reinfection probability, with the likelihood of reinfection by a high but not a low challenge dose decreasing exponentially at higher priming doses. While this interaction was likely driven by lower average infection probabilities for low-dose versus high-dose challenges, even the highest priming dose provided only negligible protection against reinfection from low-dose challenges. Similarly, pathogen loads during reinfection were significantly reduced with increasing priming doses only for birds reinfected at high but not low doses. We hypothesize that these interactions arise to some degree from fundamental differences in host immune responses across doses, with single low doses only weakly triggering host immune responses. Importantly, our results also demonstrate that reinfections can occur from a variety of exposure doses and across diverse degrees of standing immunity in this system. Overall, our study highlights the importance of considering both initial and subsequent exposure doses where repeated exposure to a pathogen is common in nature.

COMPARISON BETWEEN STANDARD ZOO QUARANTINE PRACTICES AND RISK-BASED MANAGEMENT OF ANIMAL TRANSFERS: A RETROSPECTIVE ANALYSIS OF AVIAN ACQUISITION MORBIDITY AND MORTALITY (2013-2018).

Beginning 01 January 2016, for all animals transferred into the collection, Disney's Animal Kingdom used a risk-based process that relies on pathogen hazard identification and then assessment and mitigation of the risk for each identified pathogen hazard. Data on morbidity, mortality, and disease introduction was compared for birds transferred in pre- and post-risk-based processes used during the period 2013-2018. When assessing morbidity within 3 mo of acquisition, logistic regression revealed that birds entering "straight to collection" had lower morbidity rates than those entering with either "standard quarantine" or "risk-based standard quarantine" methods (P = 0.032). Mortality within 3 mo of acquisition was not significantly different between straight-to-collection and standard quarantine or risk-based standard quarantine methods (P = 0.40). In addition, no transmissible pathogens of concern were introduced with acquired birds using either method. Implementation of a risk-based approach to animal transfers between zoos and aquariums may be an alternative method that does not pose a greater risk to animal morbidity or mortality while still protecting the collection from disease introduction.

ASSESSING THE HUMORAL RESPONSE TO AND SAFETY OF A COMMERCIALLY AVAILABLE EQUINE WEST NILE VIRUS VACCINE IN A ZOO-BASED CONSERVATION BREEDING POPULATION OF ENDANGERED GREATER SAGE-GROUSE (CENTROCERCUS UROPHASIANUS).

Greater sage-grouse (Centrocercus urophasianus) are an endangered species in Canada and have been extirpated from five states in the United States. Infectious diseases can pose a challenge to conservation efforts, and the greater sage-grouse is susceptible to West Nile virus (WNV). This study measured the humoral response to a commercially available WNV vaccine in a zoo-based conservation breeding population of greater sage-grouse. Since the initiation of the conservation program in 2014, all sage-grouse at the Calgary Zoo's Wildlife Conservation Centre have been vaccinated against WNV. Juveniles received a series of three vaccines every 2-3 wk starting around 2 wk of age; adults had received the same vaccination series at hatch and had since been boostered annually. Antibody titers were measured on 60 serum samples from 36 juveniles and 18 adults collected in 2018 using either serum neutralization or plaque-reduction neutralization methods. No detectable antibody response was noted in juveniles after their second (n = 17) or third booster vaccinations (n = 23). Only 35% of 20 adult samples collected had positive titers even after multiple years of vaccination. Only two cases of adverse vaccine reaction have been noted in this species with over 800 doses being administered between 2014 and 2020. Despite a lack of antibody response in juveniles and most adults, there have been no WNV-associated deaths in this population even with confirmed cases of WNV in free-ranging greater sage-grouse and other species in the area during this time frame, suggesting that cell-mediated immunity may be of greater importance for protection against WNV infections in this species. The initial vaccination series was changed in 2019 to a series of only two doses of vaccine, and no clinical cases or mortality from WNV occurred in 2019 or 2020 with the new protocol.

WEST NILE VIRUS SEROCONVERSION IN EASTERN LOGGERHEAD SHRIKE (LANIUS LUDOVICIANUS MIGRANS) AFTER VACCINATION WITH A KILLED VACCINE.

The loggerhead shrike (Lanius ludovicianus migrans) is a migratory songbird that has undergone massive population declines in Ontario since the 1950s. As part of a broad strategy of recovery, a captive breeding population was established in the late 1990s. This species appears to be extremely sensitive to West Nile virus (WNV) infection, with prior outbreaks at Ontario breeding facilities reaching a 100% mortality rate. This study aimed to investigate the humoral response to vaccination in juvenile birds given single versus serial booster vaccinations, as well as to assess the duration of protective virus-neutralizing titers in annually vaccinated adult birds, by measuring WNV-neutralizing antibodies via the Plaque Reduction Neutralization Test. Twenty-two adult birds and forty 18-22-day-old chicks were included in the study. Annual vaccination resulted in serum neutralizing antibody against WNV for only 59% of adult individuals 1 yr following vaccination. These results, coupled with the death of one vaccinated adult individual due to WNV infection, suggest that a second booster vaccination may be required to adequately protect adult individuals throughout the WNV transmission season. The results of the trial involving juvenile birds indicate that vaccination does not effectively stimulate the immune system of naïve juveniles to produce serum-neutralizing antibodies against WNV in the majority of tested birds, although serial booster vaccination appears to provide a level of improved seroconversion. However, the loss of 19% of naïve juveniles to natural WNV infection versus a less than 3% loss of juveniles that received at least one vaccination suggests some level of cell-mediated immunity and protection against infection takes place in juvenile birds postvaccination. The deaths of several nonvaccinated juveniles and one vaccinated adult at this study facility suggest that WNV continues to be a pathogen of high risk in this species in captivity, and likely in the wild as well.

Assembly of pigeon circovirus-like particles using baculovirus expression system.

Pigeon circovirus (PiCV) is able to infect racing and meat pigeons of all ages and is a key factor that triggers young pigeon disease syndrome (YPDS). PiCV vaccine research has been impeded because PiCV cannot be grown or propagated in cell cultures. Virus-like particles (VLPs), which can be generated by a wide range of expression systems, have been shown to have outstanding immunogenicity and constitute promising vaccines against a wide range of pathogens. Cap protein, which contains neutralizing antibody epitopes, is the only capsid protein of PiCV. In this study, the baculovirus expression system was utilized to express the PiCV Cap protein, which was self-assembled into VLPs with a spherical morphology and diameters of 15-18 nm. Specific antibodies against the Cap protein were induced after BALB/c mice immunized intramuscularly (i.m.) with VLPs combined with adjuvant. Based on these findings, PiCV VLPs may be a promising candidate vaccine against PiCV.

Differential house finch leukocyte profiles during experimental infection with Mycoplasma gallisepticum isolates of varying virulence.

Leukocyte differentials are a useful tool for assessing systemic immunological changes during pathogen infections, particularly for non-model species. To date, no study has explored how experimental infection with a common bacterial pathogen, Mycoplasma gallisepticum (MG), influences the course and strength of haematological changes in the natural songbird host, house finches. Here we experimentally inoculated house finches with MG isolates known to vary in virulence, and quantified the proportions of circulating leukocytes over the entirety of infection. First, we found significant temporal effects of MG infection on the proportions of most cell types, with strong increases in heterophil and monocyte proportions during infection. Marked decreases in lymphocyte proportions also occurred during infection, though these proportional changes may simply be driven by correlated increases in other leukocytes. Second, we found significant effects of isolate virulence, with the strongest changes in cell proportions occurring in birds inoculated with the higher virulence isolates, and almost no detectable changes relative to sham treatment groups in birds inoculated with the lowest virulence isolate. Finally, we found that variation in infection severity positively predicted the proportion of circulating heterophils and lymphocytes, but the strength of these correlations was dependent on isolate. Taken together, these results indicate strong haematological changes in house finches during MG infection, with markedly different responses to MG isolates of varying virulence. These results are consistent with the possibility that evolved virulence in house finch MG results in higher degrees of immune stimulation and associated immunopathology, with potential direct benefits for MG transmission. RESEARCH HIGHLIGHTS House finches show a marked pro-inflammatory response to M. gallisepticum infection. Virulent pathogen isolates produce stronger finch white blood cell responses. Among birds, stronger white blood cell responses are associated with higher infection severity.

The Effects of Silymarin on Acetaminophen-Induced Acute Hepatic and Renal Toxicities in Domestic Pigeons (Columba livia).

This study evaluated the effects of silymarin on acetaminophen-induced acute liver and kidney toxicities in domestic pigeons (Columba livia). Standard colorimetric methods with commercial kits were used to measure the serum activities or levels of biomarkers associated with liver and kidney damage, such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, urea, uric acid, total protein, albumin, and total cholesterol, in 21 pigeons randomly assigned into 3 groups (A, B, and C). Groups A and B were administered acetaminophen 3000 mg/ kg PO q24h at the beginning of the experiment (hour 0). Group B pigeons were further treated with silymarin 35 mg/kg, starting at 12 hours after acetaminophen exposure (post-AA), with the silymarin treatment continuing q12h for 3 days. Group C pigeons served as the control group and were given tap water as the placebo. Blood was collected from the pigeons at hours 0, 12, 24, 48, and 72 of the experiment for serum biochemistry analyses. The results showed that treatment of group B pigeons with silymarin decreased the serum levels of aspartate aminotransferase, alanine aminotransferase, urea, and uric acid compared with the untreated control (group A). It also prevented decreases in serum alkaline phosphatase, total protein, albumin, and cholesterol seen in Group A. Mortality, which was 86% in the untreated control (group A), was completely prevented in group B. It was concluded that silymarin remediated the effects of acetaminophen-induced acute toxic liver and kidney injuries, which may result in pigeon mortality.

A recombinant vaccine of Riemerella anatipestifer OmpA fused with duck IgY Fc and Schisandra chinensis polysaccharide adjuvant enhance protective immune response.

Riemerella anatipestifer (R. anatipestifer) causes septicemia and infectious serositis in domestic ducks, leading to high mortality and great economic losses worldwide. Vaccination is currently considered the best strategy to prevent R. anatipestifer infection in ducklings. In this study, we fused the duck IgY Fc gene to the outer membrane protein A (ompA) of R. anatipestifer. The eukaryotic expression plasmid carrying the fusion gene was transformed into Pichia pastoris (P. pastoris) to express the recombinant ompA and ompA-Fc proteins. Then, the effects of fused Fc on the vitality and antigen processing efficiency of duck peritoneal macrophages (PMø) were evaluated in vitro, whereas their immunogenicity was evaluated in vivo. Furthermore, Schisandra chinensis polysaccharide (SCP) was used to evaluate its immune-conditioning effects on the activation of PMø. SCP was also used as adjuvant to investigate immunomodulation on immunoresponses induced by the fused ompA-Fc in ducklings. The conventional Freund's incomplete adjuvant served as the control of SCP. Notably, ompA-Fc promoted phagocytosis of PMø and significantly increased serum antibody titers, CD4+ and CD8+ T-lymphocyte counts, lymphocyte transformation rate, and serum levels of IL-2 and IL-4. In addition, ducklings injected with the ompA-Fc vaccine exhibited considerably greater resistance to the R. anatipestifer challenge than those that received vaccines based on standalone ompA. Of note, SCP was demonstrated to boost the secretion of nitric oxide (NO), IL-1ß, IL-6, TNF-α, and IFN-ß by duck macrophages. In addition, the supplementation of SCP adjuvant to the ompA-Fc vaccines led to the further enhancement of immune response and vaccine protection. The dose of 200 µg/mL showed the most pronounced effects. This study provided valuable insights into protective strategies against R. anatipestifer infection.

Spotlight on avian pathology: fowlpox virus.

Fowlpox virus is the type species of an extensive and poorly-defined group of viruses isolated from more than 200 species of birds, together comprising the avipoxvirus genus of the poxvirus family. Long known as a significant poultry pathogen, vaccines developed in the early and middle years of the twentieth century led to its effective eradication as a problem to commercial production in temperate climes in developed western countries (such that vaccination there is now far less common). Transmitted mechanically by biting insects, it remains problematic, causing significant losses to all forms of production (from backyard, through extensive to intensive commercial flocks), in tropical climes where control of biting insects is difficult. In these regions, vaccination (via intradermal or subcutaneous, and increasingly in ovo, routes) remains necessary. Although there is no evidence that more than a single serotype exists, there are poorly-described reports of outbreaks in vaccinated flocks. Whether this is due to inadequate vaccination or penetrance of novel variants remains unclear. Some such outbreaks have been associated with strains carrying endogenous, infectious proviral copies of the retrovirus reticuloendotheliosis virus (REV), which might represent a pathotypic (if not newly emerging) variant in the field. Until more is known about the phylogenetic structure of the avipoxvirus genus (by more widespread genome sequencing of isolates from different species of birds) it remains difficult to ascertain the risk of novel avipoxviruses emerging from wild birds (and/or by recombination/mutation) to infect farmed poultry.

The effects of acaricide treatment of sheep on red grouse Lagopus lagopus scotica tick burdens and productivity in a multi-host system.

Ixodes ricinus (Ixodida: Ixodidae) ticks are of economic and pathogenic importance across Europe. Within the uplands of the U.K., management to reduce ticks is undertaken to benefit red grouse Lagopus lagopus scotica (Galliformes: Phasianidae). Management strategies focus on the acaricide treatment of domestic sheep Ovis aries (Artiodactyla: Bovidae), but the effectiveness of this is less certain in the presence of wild hosts, particularly red deer Cervus elaphus (Artiodactyla: Cervidae) and mountain hare Lepus timidus (Lagomorpha: Leporidae). This study examines the effects of sheep management on grouse tick burdens and productivity using sites with a range of wild host densities. Sites at which applications of acaricide were more frequent had lower tick burdens; this relationship was similar on sites with a range of deer densities. However, no direct link was detected between acaricide treatment interval and grouse productivity. Sites with higher deer densities had higher grouse tick burdens and lower productivity [mean ± standard error (SE) young : adult ratio: 1.2 ± 0.2] compared with sites with lower deer densities (mean ± SE young : adult ratio: 1.8 ± 0.1). Sites with higher grouse brood sizes and higher proportions of hens with broods were also those with higher mountain hare abundance indices. This study highlights the importance of the frequent treatment of sheep with acaricide to reduce tick burdens on grouse, even in the presence of wild hosts.

Combined effects of retinol, ascorbic acid and α-tocopherol on diurnal variations in rectal temperature of Black Harco pullets subjected to heat stress.

The experiment was performed with the aim of determining the effect of co-administration of antioxidant vitamins, retinol, ascorbic acid and α-tocopherol on rectal temperature (RT) fluctuations in pullets during the hot-dry season in Nigeria. Forty-eight Black Harco pullets, aged 16 weeks and weighing 1.5 ± 0.03 kg were divided by simple random sampling into two groups, consisting of 28 treated and 20 control Black Harco pullets. The RTs of 28 treated and 20 control Black Harco pullets were measured hourly for 3 days, 3 days apart, from 06:00 to 19:00 h (GMT + 1) with a standard clinical thermometer. The treated pullets were administered individually with the vitamins orally in water, while the control pullets were given only water. The lowest hourly RT of 40.9 ± 0.04 °C was obtained in treated pullets at 06:00 h, while the highest value of 41.1 ± 0.01 °C was recorded from 17:00 to 19:00 h (P < 0.001). In control pullets, the RT rose significantly from 41.0 ± 0.03 °C at 06:00 h to the maximum value of 41.6 ± 0.04 °C at 15:00 h (P < 0.001). The pullets co-administered with retinol, ascorbic acid and α-tocopherol had consistently lower RT values than those of control pullets, especially during the hot hours of the day, from 13:00 to 17:00 h. It is concluded that co-administration of retinol, ascorbic acid and α-tocopherol, by preventing a rise in body temperature, ameliorated heat stress, and may enhance productivity of pullets reared under unfavourable, thermal environment conditions.

ANALYSIS OF HISTORICAL MEDICAL RECORDS OF CALIFORNIA CONDORS ( GYMNOGYPS CALIFORNIANUS) ADMITTED FOR LEAD EXPOSURE TO THE LOS ANGELES ZOO AND BOTANICAL GARDENS BETWEEN 1997 AND 2012: A CASE SERIES STUDY.

Lead toxicosis remains the primary cause of death in wild populations of California condors ( Gymnogyps californianus). Many condors require medical intervention with lead chelation therapy, among other conservation measures, to survive in the wild. An analysis of historical medical records of California condors admitted for lead exposure to the Los Angeles Zoo and Botanical Gardens (LA Zoo) between 1997 and 2012 was performed to investigate clinical presentation, radiographic findings, and treatment along with the potential impact of these factors on recovery and successful release back into the wild. Of 100 individual condors presented to the LA Zoo for suspected lead toxicosis during this period, 84 condors had records for initial laboratory blood lead levels. For these 84 condors (40 [47.6%] females and 44 [52.4%] males), 277 initial laboratory blood lead levels in total were recorded because of repeated admissions. Thirty-two (38%) condors were admitted once to the zoo and 62% were admitted two or more times. Clinical signs were not observed in 87.5% of the condors admitted with median blood lead concentrations of 26 µg/dl. Of the radiographs taken on initial presentation, 65% did not show evidence of gastrointestinal metallic foreign bodies. Various treatments protocols with edetatum calcium disodium, dimercaptosuccinic acid, and lactated Ringer's solution were documented in the medical records. Of the 277 admissions, 154 admissions had a recorded outcome posttreatment of which 140 (91%) admissions were released back to the wild. This study contributes to a better understanding of how intervention and therapeutic approaches have been essential for the recovery, release, and sustainability of these birds as a wild population. Consistency in data collection of California condors admitted for diagnosis and treatment of lead toxicosis is needed to better assess the impacts of medical interventions.

Intersectoral action for health: preventing psittacosis spread after one reported case.

Zoonotic diseases are a significant health threat for humans and animals. To better understand the epidemiology, etiology, and pathology of infectious agents affecting humans and animals combined approaches are needed. Here we describe an epidemiological investigation conducted by physicians and veterinarians after a reported case of psittacosis. Upon admission suffering from respiratory distress syndrome in a hospital and with a history of bird contact, a female patient was serologically diagnosed with psittacosis. After the case notification, veterinarians were able to investigate the source of infection by detecting Chlamydia psittaci in her pet cockatiel. The bird was hospitalized and successfully treated. In addition, the establishment where the pet bird was purchased was traced and through molecular techniques other birds intended to be sold as pets tested positive for C. psittaci. As a result, sanitary measures were applied and the establishment then was closed down. The birds intended for the pet commerce were treated and retested with negative molecular results for C. psittaci, thus avoiding disease propagation. Reliable data about zoonotic diseases can only be generated through the application of multidisciplinary approaches which take into account the epidemiological factors and interactions of humans, animals and their environments as an integrated system.

West Nile Virus Infection in Ruffed Grouse ( Bonasa umbellus): Experimental Infection and Protective Effects of Vaccination.

Ruffed grouse ( Bonasa umbellus) population numbers in Pennsylvania dramatically declined during the early 2000s and have subsequently remained depressed throughout much of the state. While this decline has been temporally associated with the presence of West Nile virus (WNV), lack of information on the WNV susceptibility of this popular game bird species has limited the ability to interpret the potential impacts of WNV. To address this knowledge gap, virologic, immunologic, pathologic, and clinical responses as well as protective effects of vaccination following experimental WNV inoculation in ruffed grouse were assessed. Four of 10 (40%) naive, WNV-inoculated grouse succumbed to infection within 8 days and had moderate mean peak viremia titers (107.0 plaque-forming units [PFU]/ml serum); severe necrotizing myocarditis with widespread, corresponding immunohistochemical labeling; and minimal encephalitis. Grouse that survived to the prescribed end point of 14 days postinoculation (6/10; 60%) had slightly lower mean peak viremia titers (106.8 PFU/ml serum), moderate myocardial lesions, and more widespread brain lesions with rare corresponding immunohistochemical labeling. Vaccinated, WNV-inoculated birds ( n = 5) had lower mean peak viremia titers (103.6 PFU/ml serum) and minimal lesions, and sham-inoculated, in-contact control birds ( n = 3) had no evidence of infection. All surviving, inoculated birds seroconverted, and WNV-specific antibodies were detectable in serum and Nobuto filter paper strip-eluted blood samples. These data suggest that WNV could serve as an additional population pressure on ruffed grouse in regions where transmission levels are high and WNV competent, ornithophilic vectors exist.

THE PASSAGE AND DURATION OF ANTIBODIES TO WEST NILE VIRUS IN HUMBOLDT PENGUINS (SPHENISCUS HUMBOLDTI).

West Nile virus (genus Flavivirus) outbreaks and mortality events have been documented in both wild and captive avian species, including penguins. Serologic response to vaccination in avian species has varied and appears to be largely species dependent; however, Humboldt penguins ( Spheniscus humboldti ) previously showed excellent rates of seroconversion. The goal of this study was to determine virus neutralization titers of 17 Humboldt penguin hens and their subsequent eggs, chicks, or both following vaccination with a killed West Nile vaccine. Chicks were also vaccinated at 56, 70, and 84 days old. Titers were measured from 10-346 days prior to lay as well as serially in seven chicks. Data collected showed positive rank correlation between maternal titers and yolk titers (ρ = 0.90, P < 0.0001, n = 14) but no association between booster vaccination and yolk titers. All seven chicks had detectable antibody on days 14 and 28, and antibody levels had increased (relative to day 56) in 3 of 6 chicks (50%; 95% confidence interval 14-86%) by day 112. Further information is provided on a suggested vaccination schedule for Humboldt penguin chicks based on a time-dependent decline in maternal antibody titers. Cell-mediated immunity and experimental challenge following vaccination have not yet been investigated in this species.

INVESTIGATION OF THE PRESENCE OF ATOXOPLASMA SPP. IN BLUE-CROWNED LAUGHINGTHRUSH (DRYONASTES COURTOISI) ADULTS AND NEONATES.

Between 1996 and 2013, 71 blue-crowned laughingthrush (Dryonastes courtoisi) chicks, a small passerine bird endemic to China, were born at Mulhouse Zoo in northeast France. None of them survived past 1 yr, and 82% died between 0 and 6 days old of an unidentified cause and despite an attempt to establish an artificial breeding protocol. Atoxoplasma spp., causing a disease known as systemic isosporosis, is a coccidian parasite that can infect several species of birds. Mulhouse's adult birds were suspected to be infected with Atoxoplasma spp. and to transmit this parasite to their offspring. A treatment with toltrazuril (Baycox® 2.5%) was implemented in the four adult birds. Coprologic examinations were performed before, during, and after the treatment to quantify the parasite load in feces. Polymerase chain reaction (PCR) assays were used to test blood samples from the adult and liver, lung, gizzard, and kidney samples from 10 chicks to detect Atoxoplasma spp. Five of the 10 chicks had some tissue samples positive for Atoxoplasma spp. in at least one of the three repeats of the atoxoplasmosis PCR. An average of 181 Isospora spp. oocysts per gram of feces were found in the group of adults before treatment. This number was reduced to zero 1 wk after the beginning of the toltrazuril treatment. The PCR results suggest a transovarian transmission of Atoxoplasma spp., but further investigation is needed for confirmation. The treatment with toltrazuril appears to allow a significant reduction of the parasite excretion.

Compendium of Measures to Control Chlamydia psittaci Infection Among Humans (Psittacosis) and Pet Birds (Avian Chlamydiosis), 2017.

Psittacosis, also known as parrot fever and ornithosis, is a bacterial infection that can cause severe pneumonia and other serious health problems in humans. It is caused by Chlamydia psittaci. Reclassification of the order Chlamydiales in 1999 into 2 genera (Chlamydia and Chlamydophila) was not wholly accepted or adopted. This resulted in a reversion to the single, original genus Chlamydia, which now encompasses all 9 species including Chlamydia psittaci. During 2003-2014, 112 human cases of psittacosis were reported to the Centers for Disease Control and Prevention through the Nationally Notifiable Diseases Surveillance System. While many types of birds can be infected by C psittaci, in general, the literature suggests that human cases can most often occur after exposure to infected parrot-type birds kept as pets, especially cockatiels, parakeets, and conures. In birds, C psittaci infection is referred to as avian chlamydiosis. Infected birds shed the bacteria through feces and nasal discharges, and humans become infected from exposure to these materials. This compendium provides information about psittacosis and avian chlamydiosis to public health officials, physicians, veterinarians, the pet bird industry, and others concerned with controlling these diseases and protecting public health. The recommendations in this compendium provide standardized procedures to control C psittaci infections. This document will be reviewed and revised as necessary, and the most current version replaces all previous versions. This document was last revised in 2010. Major changes in this version include a recommendation for a shorter treatment time for birds with avian chlamydiosis, additional information about diagnostic testing, including genotyping, clearer language associated with personal protective equipment recommended for those caring for confirmed or exposed birds, and incorporating a grading scale with recommendations generally based on the United States Preventive Services Task Force's methods.

Does allopreening control avian ectoparasites?

For birds, the first line of defence against ectoparasites is preening. The effectiveness of self-preening for ectoparasite control is well known. By contrast, the ectoparasite control function of allopreening-in which one birds preens another-has not been rigorously tested. We infested captive pigeons with identical numbers of parasitic lice, and then compared rates of allopreening to the abundance of lice on the birds over time. We documented a negative relationship between rates of allopreening and the number of lice on birds. Moreover, we found that allopreening was a better predictor of louse abundance than self-preening. Our data suggest that allopreening may be a more important means of ectoparasite defence than self-preening when birds live in groups. Our results have important implications for the evolution of social behaviour.

Recommendations for a standardized avian coronavirus (AvCoV) nomenclature: outcome from discussions within the framework of the European Union COST Action FA1207: "towards control of avian coronaviruses: strategies for vaccination, diagnosis and surveillance".

Viruses within the Coronaviridae family show variations within their genome sequences, especially within the major structural protein the Spike (S) glycoprotein gene. Therefore, many different antigenic forms, serotypes or variant strains of avian coronaviruses (AvCoV) exist worldwide. Only a few of them, the so called protectotypes, cross protect against different serotypes. New serotypes arise by recombination or spontaneous mutations. From time to time, antigenic virus variants appear, which differ significantly from known serotypes. The result of this variability is an inconsistent nomenclature and classification of virus strains. Furthermore, there are currently no standard classification methods defined. Within the framework of the COST Action FA1207 "Towards control of avian coronaviruses: strategies for diagnosis, surveillance and vaccination" (working groups "Molecular virology" and "Epidemiology"), we aimed at defining and developing a unified and internationally standardized nomenclature and classification of AvCoVs. We recommend the use of "CoV Genus/AvCov/host/country/specimen id/year" to refer to AvCoV strains.

Can acaricide-impregnated leg bands fitted to female red grouse reduce sheep tick parasitization of chicks and increase chick survival?

In parts of northern England, North Wales and the Scottish Highlands, increasing numbers of sheep ticks Ixodes ricinus (Ixodida: Ixodidae), and the louping ill virus they can carry, are considered to be important factors that reduce red grouse Lagopus lagopus scotica productivity. The present study tested this hypothesis by fitting adult female grouse with leg bands impregnated with the acaricide cypermethrin to experimentally control ticks on their chicks on two managed grouse moors in northeast Scotland. The chicks of females fitted with acaricide leg bands showed reduced tick infestations and improved survival in one of the two study years, relative to chicks of control females. Acaricide leg bands constitute a potential management technique that may be adopted by grouse moor managers in circumstances of high tick infestations on grouse chicks.