Duck “beak atrophy and dwarfism syndrome” disease complex: Interplay of novel goose parvovirus‐related virus and duck circovirus?

As a newly emerged infectious disease, duck “beak atrophy and dwarfism syndrome (BADS )” disease has caused huge economic losses to waterfowl industry in China since 2015. Novel goose parvovirus‐related virus (NGPV ) is believed the main pathogen of BADS disease; however, BADS is rarely reproduced by infecting ducks with NGPV alone. As avian circovirus infection causes clinical symptoms similar to BADS , duck circovirus (DuCV ) is suspected the minor pathogen of BADS disease. In this study, an investigation was carried out to determine the coinfection of NGPV and DuCV in duck embryos and in ducks with BADS disease. According to our study, the coinfection of emerging NGPV and DuCV was prevalent in East China (Shandong, Jiangsu and Anhui province) and could be vertical transmitted, indicating their cooperative roles in duck BADS disease.     

Isolation and characterization of novel goose parvovirus‐related virus reveal the evolution of waterfowl parvovirus

Short beak and dwarfism syndrome (SBDS ) has been constantly breaking out in China since 2015. It is caused by a novel goose parvovirus‐related virus (NGPV ) and can severely restrict the growth of ducks. In this study, seven NGPV stains were isolated from different regions in China between 2015 and 2016. To better understand the correlation between NGPV and goose parvovirus (GPV ), we conducted complete genome sequencing and a comprehensive analysis of the NGPV genome. The phylogenetic and alignment analysis showed that NGPV is a branch of GPV , sharing 92.2%–97.1% nucleotide identity with GPV . Compared with classical GPV , five consensus nucleotide mutations in all the seven NGPV isolates and two 14‐nucleotide‐pair deletions in six NGPV isolates were found in the inverted terminal repeats, twelve and eight synchronous amino acid changes were found in the replication protein and capsid protein of NGPV , respectively, which might be important for viral gene regulation, humoral immune responses, and host transfer. Notably, SDLY 1602 was demonstrated a recombinant strain, with the potential major parent GPV vaccine strain 82‐0321v and the minor parent GPV wild strain GD aGPV . This is the first report showing that the recombination between two classical GPV strains generated a NGPV strain circulating in nature. This study will advance our understanding of NGPV molecular biology and facilitate to elucidate the evolutionary characteristics of GPV .     

Inter‐Epidemic and Between‐Season Persistence of Rift Valley Fever: Vertical Transmission or Cryptic Cycling?

Rift Valley fever (RVF) is an emerging zoonotic mosquito‐borne infectious disease that has been identified as a risk for spread to other continents and can cause mass livestock mortality. In equatorial Africa, outbreaks of RVF are associated with high rainfall, when vector populations are at their highest. It is, however, unclear how RVF virus persists during the inter‐epidemic periods and between seasons. Understanding inter‐epidemic persistence as well as the role of vectors and hosts is paramount to creating effective management programmes for RVF control. We created a mathematical model for the spread of RVF and used the model to explore different scenarios of persistence including vertical transmission and alternate wildlife hosts, with a case study on buffalo in Kruger National Park, South Africa. Our results suggest that RVF persistence is a delicate balance between numerous species of susceptible hosts, mosquito species, vertical transmission and environmental stochasticity. Further investigations should not focus on a single species, but should instead consider a myriad of susceptible host species when seeking to understand disease dynamics.     

First Experimental Evidence for the Transmission of Chlamydia psittaci in Poultry through Eggshell Penetration

Eggshell penetration by pathogens is considered a potential route for their transmission in poultry flocks. Additionally, in case of zoonotic pathogens, contact with infected eggs or their consumption can result in human infection. Chlamydia psittaci is a zoonotic bacterium that causes a respiratory disease in poultry and humans. In this study, we provide an experimental evidence for eggshell penetration by C. psittaci. Additionally, we show that after eggshell penetration, C. psittaci could eventually infect the growing embryo. Our findings portend the potential of horizontal trans‐shell transmission as a possible route for the spread of C. psittaci infection in poultry flocks. Considering that horizontal transmission of pathogens via eggs mainly occurs in hatcheries and hatching cabinets, we suggest the latter as critical control points in the transmission of C. psittaci to hatching chicks and broilers, as well as to the hatchery workers and consumers of table eggs.     

Living‐Related Liver Transplantation for Siblings with Progressive Familial Intrahepatic Cholestasis 2, with Novel Genetic Findings

Progressive familial intrahepatic cholestasis is a syndrome of severe cholestasis progressing to biliary cirrhosis and liver failure that develops in childhood. This report describes two siblings with PFIC‐2 who underwent living‐related liver transplantation from their genetically proven heterozygous parents. Both patients had normal gamma‐glutamyl transpeptidase levels, but showed severe pruritus with sleep disturbance, cholestasis, jaundice and growth failure. Genetic testing of each patient revealed two missense mutations of the bile salt export pump, S901R and C1083Y, which have not previously been associated with PFIC‐2. Usual medical treatment failed to improve their clinical symptoms, and the two siblings underwent living‐related liver transplantation from their heterozygous parents. The transplants improved their clinical symptoms significantly, and the patients have since shown age‐appropriate growth. Electron microscopic findings of the explanted liver of the younger sister revealed dense and amorphous bile, which is characteristic of PFIC‐2. In the cases presented here, living‐related liver transplantation from a heterozygous donor was associated with better quality of life and improvement of growth, and thus appears to be a feasible option for PFIC‐2 patients. Mutation analysis is a useful tool to help decide the course of treatment of PFIC.     

Targeted HIV testing at birth supported by low and predictable mother‐to‐child transmission risk in Botswana

Introduction

Most African countries perform infant HIV testing at 6 weeks or later. The addition of targeted testing at birth may improve retention in care, treatment outcomes and survival for HIV‐infected infants.

Methods

HIV‐exposed infants were screened as part of the Early Infant Treatment (EIT) study in Botswana. Screened infants were ≥35 weeks gestational age and ≥2000 g at birth. Risk factors for mother‐to‐child transmission (MTCT) were assessed by maternal obstetric card or verbally. Risk factors included <8 weeks ART in pregnancy, last known CD4 <250 cells/mm³, last known HIV RNA >400 copies/mL, poor maternal ART adherence, lack of maternal zidovudine (ZDV) in labour, or lack of infant post‐exposure prophylaxis. Infants underwent dried blood spot testing by Roche Cobas Ampliprep/Cobas Taqman HIV‐1 qualitative PCR.

Results

From April 2015 to April 2016, 2303 HIV‐exposed infants were tested for HIV in the EIT study. Of these, 369 (16%) were identified as high risk for HIV infection by information available at birth, and 12 (0.5% overall, 3.25% of high risk) were identified as HIV positive at birth. All 12 positive infants were identified as high risk at the time of screening, and only 2 risk factors were required to identify all positive infants: either <8 weeks of maternal ART in pregnancy (75%) or lack of maternal HIV suppression at last test (25%).

Conclusions

In utero MTCT occurred only among infants identified as high risk at delivery, using information available from the mother or obstetric record. Birth testing that targets high‐risk infants based on maternal ART receipt is likely to identify the majority of in utero HIV transmissions, and allows early ART initiation for these infants.

     

Foot‐and‐mouth Disease Transmission in Africa: Implications for Control,a Review

In Africa, for the control of foot‐and‐mouth disease (FMD), more information is needed on the spread of the disease at local, regional and inter‐regional level. The aim of this review is to identify the role that animal husbandry, trade and wildlife have on the transmission of FMD and to provide a scientific basis for different FMD control measures in Africa. Review of literature, published reports and databases shows that there is more long distance spread of FMD virus serotypes within North, West, Central and East Africa than in southern Africa. In North, West, Central and East Africa migratory animal husbandry systems often related with search for grazing and water as well as trade are practiced to a greater extent than in southern Africa. In southern Africa, the role of African buffalo (Syncerus caffer) is more extensively studied than in the other parts of Africa, but based on the densities of African buffalo in Central and East Africa, one would assume that buffalo should also play a role in the epidemiology of FMD in this part of Africa. More sampling of buffalo is necessary in West, Central and East Africa. The genetic analysis of virus strains has proven to be valuable to increase our understanding in the spread of FMD in Africa. This review shows that there is a difference in FMD occurrence between southern Africa and the rest of the continent; this distinction is most likely based on differences in animal husbandry and trade systems. Insufficient data on FMD in wildlife outside southern Africa is limiting our understanding on the role wildlife plays in the transmission of FMD in the other buffalo inhabited areas of Africa.     

Novel model for studying hematogenous infection in an experimental setting of implant‐related infection by a community‐acquired methicillin‐resistant S. aureus Strain

The aim of this study is to establish a new experimental model of hematogenous implant‐related infection (IRI) by a community‐acquired methicillin‐resistant S. aureus (CA‐MRSA) strain. Cylindrical porous tantalum intramedullary implants were inserted in the proximal right tibia of 30 male white rabbits after administration of antibiotic prophylaxis. Four weeks later and without antibiotic prophylaxis, 20 animals received 1 ml of inoculum of two different concentrations (study groups A and B) of CA‐MRSA strain through an ipsilatelar femoral artery catheter. The remaining 10 received normal saline instead (control group C). Surviving animals were sacrificed 4 weeks later. Sterile bone, bone marrow biopsies, and implants were harvested for culture and histological evaluation. Ten animals receiving 5 × 10⁸cfu/ml (group A) died within 48–72 h due to septic shock. Blood cultures were positive; histology demonstrated acute infection. Ten animals received bacterial load of 3 × 10⁸cfu/ml (group B) and all survived; two had negative Gram‐stain and cultures but PCR and RT‐PCR results demonstrated the viability of the microorganisms, while periprosthetic osteolysis and histological evaluation indicated subacute osteomyelitis; eight animals established periprosthetic infection, osteomyelitis, and septic arthritis documented by positive Gram‐stain, cultures, subperiosteal reaction, and chronic infection on histology. Control group specimens demonstrated no signs of infection. Histopathological semiquantitative scoring was used to compare the three groups. Comparison of groups A and B with control group and between group A and B showed statistically significant difference (p < 0.05) in all parameters except for periosteal reaction between groups B and C (p = 0.354). This novel, reproducible experimental model will facilitate the study of hematogenous CA‐MRSA IRIs. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1355–1362, 2008     

Bril: A Novel Bone‐Specific Modulator of Mineralization

In the course of attempting to define the bone “secretome” using a signal‐trap screening approach, we identified a gene encoding a small membrane protein novel to osteoblasts. Although previously identified in silico as ifitm5, no localization or functional studies had been undertaken on this gene. We characterized the expression patterns and localization of this gene in vitro and in vivo and assessed its role in matrix mineralization in vitro. The bone specificity and shown role in mineralization led us to rename the gene bone restricted ifitm‐like protein (Bril). Bril encodes a 14.8‐kDa 134 amino acid protein with two transmembrane domains. Northern blot analysis showed bone‐specific expression with no expression in other embryonic or adult tissues. In situ hybridization and immunohistochemistry in mouse embryos showed expression localized on the developing bone. Screening of cell lines showed Bril expression to be highest in osteoblasts, associated with the onset of matrix maturation/mineralization, suggesting a role in bone formation. Functional evidence of a role in mineralization was shown by adenovirus‐mediated Bril overexpression and lentivirus‐mediated Bril shRNA knockdown in vitro. Elevated Bril resulted in dose‐dependent increases in mineralization in UMR106 and rat primary osteoblasts. Conversely, knockdown of Bril in MC3T3 osteoblasts resulted in reduced mineralization. Thus, we identified Bril as a novel osteoblast protein and showed a role in mineralization, possibly identifying a new regulatory pathway in bone formation.     

Post‐Weaning Multisystemic Wasting Syndrome and Other PCV2‐Related Problems in Pigs: a 12‐Year Experience

Post‐weaning multisystemic wasting syndrome (PMWS) and other porcine circovirus type 2 (PCV2)‐related diseases have been reported throughout the world for about 10 years. The present paper reviews the knowledge acquired in different fields and is largely based on the authors’ experience. The horizontal transmission of PCV2 is widely documented. Contact between pigs is the main route of transmission for both PCV2 and PMWS. However, experimental inoculation of PCV2 to pigs does not give consistent results and severe clinical signs as encountered in the field are rarely obtained. It is thus acknowledged that additional conditions are required for the disease to be severe in growing pigs. These are not all known but co‐infections are thought to act as triggers. The spread of such triggers/enhancers, which may or may not be infectious, could have played a role in PMWS dissemination via normal national and international trade, in some cases conferring an epidemic pattern to this spread. Most of the risk factors identified in surveys relate to poor biosecurity and inadequate hygiene/husbandry/herd management. The good correlation between viral burden in the tissues and disease severity emphasized the role of infection pressure. Genomic analysis showed great similarities between PCV2 isolates. However, although two main genotypes (genogroups) could be distinguished from the phylogenic trees, and changes with time, no clear relationship with strain virulence was apparent. Isolates detected in PMWS‐positive pigs could also be detected in healthy pigs from healthy farms. A strong sow effect was observed in disease expression in the offspring. Colostrum composition and colostrum intake are supposed to be key components of disease expression. Medication is relatively inefficient as a control measure. Commercial PCV2 vaccines are now becoming available. However, losses as a result of PMWS and PCV2‐related diseases are greatly reduced by applying appropriate hygiene and husbandry practices.     

False‐Positive Results in Metagenomic Virus Discovery: A Strong Case for Follow‐Up Diagnosis

A viral metagenomic approach using virion enrichment, random amplification and next‐generation sequencing was used to investigate an undiagnosed cluster of dairy cattle presenting with high persistent fever, unresponsive to anti‐microbial and anti‐inflammatory treatment, diarrhoea and redness of nose and teat. Serum and whole blood samples were taken in the predicted hyperviraemic state of an animal that a few days later presented with these clinical signs. Bioinformatics analysis of the resulting data from the DNA virus identification workflow (a total of 32 757 sequences with average read length 335 bases) initially demonstrated the presence of parvovirus‐like sequences in the tested blood sample. Thorough follow‐up using specific real‐time RT‐PCR assays targeting the detected sequence fragments confirmed the presence of these sequences in the original sample as well as in a sample of an additional animal, but a contamination with an identical genetic signature in negative extraction controls was demonstrated. Further investigation using an alternative extraction method identified a contamination of the originally used Qiagen extraction columns with parvovirus‐like nucleic acids or virus particles. Although we did not find any relevant virus that could be associated with the disease, these observations clearly illustrate the importance of using a proper control strategy and follow‐up diagnostic tests in any viral metagenomic study.     

A Novel Two‐Stage Surgical Approach to Treat Chronic Lymphedema

Surgical treatment of chronic lymphedema has seen significant advances. Suction‐assisted protein lipectomy (SAPL) has been shown to safely and effectively reduce the solid component of swelling in chronic lymphedema. However, these patients must continuously use compression garments to control and prevent recurrence. Microsurgery procedures, including lymphaticovenous anastomosis (LVA) and vascularized lymph node transfer (VLNT), have been shown to be effective in the management of the fluid component of lymphedema and allow for decreased garment use. SAPL and VLNT were applied together in a two‐stage approach in two patients with chronic lymphedema after treatment for breast cancer. SAPL was used first to remove the chronic, solid component of the soft‐tissue excess. Volume excess in our patients' arms was reduced an average of approximately 83% and 110% after SAPL surgery. After the arms had sufficiently healed and the volume reductions had stabilized, VLNT was performed to reduce the need for continuous compression and reduce fluid re‐accumulation. Following the VLNT procedures, the patients were able to remove their compression garments consistently during the day and still maintain their volume reductions. Neither patient had any postoperative episodes of cellulitis. SAPL and VLNT can be combined to achieve optimal outcomes in patients with chronic lymphedema.     

Minimizing the risk of non‐vertical,non‐sexual HIV infection in children – beyond mother to child transmission

After witnessing an episode of poor injection safety in large numbers of children in a rural under‐resourced hospital in Uganda, we briefly review our own experience and that of others in investigating HIV infection in children considered unlikely to be through commonly identified routes such as vertical transmission, sexual abuse or blood transfusion. In the majority of cases, parents are HIV uninfected. The cumulative experience suggests that the problem is real, but with relatively low frequency. Vertical transmission is the major route for HIV to children. However, factors such as poor injection safety, undocumented surrogate breast feeding, an HIV‐infected adult feeding premasticated food to a weaning toddler, poor hygienic practice in the home and using unsterilised equipment for minor surgical or traditional procedures are of cumulative concern.     

Lack of Evidence of Spill‐Over of Salmonella enterica Between Cattle and Sympatric Iberian ibex (Capra pyrenaica) from a Protected Area in Catalonia,NE Spain

Salmonella enterica is a zoonotic agent of worldwide importance found in a wide range of wild hosts. However, its prevalence in many popular game species has never been assessed. Iberian ibex (Capra pyrenaica) is the main game caprinae of the Iberian Peninsula and around two thousand individuals are hunted every year for trophy or for home consumption. In this work, 313 Iberian ibexes from the Ports de Tortosa i Beseit National Game Reserve (NE Spain) were tested for Salmonella enterica in faeces, and anti microbial susceptibility was determined. The exact location of shooting or capture was recorded with a GPS device to study the links of Salmonella infection with cattle presence and human proximity. Additionally, samples were taken from cattle grazing inside this reserve (n = 73). Only three Iberian ibexes (0.96%, 95% CI 0.2–2.8) were positive to Salmonella (serotype Enteritidis, Bardo and 35:r:z35), while prevalence was moderate in cattle: 21.92% (95% CI 13.10–33.14, serotype Meleagridis, Anatum, Kedougou and Othmarschen). All isolates were susceptible to the anti microbial agents tested. Moreover, a case of fatal septicaemic salmonellosis in an 11‐year‐old male Iberian ibex is described where Salmonella enterica serotype Enteritidis was isolated from the lung, liver and spleen samples. The low prevalence of Salmonella in Iberian ibex and the lack of shared serotypes suggest no association to cattle. Despite this, game meat aimed for human consumption should be examined, and it is strongly recommended that hunters and game keepers manipulate animals and carcasses under maximal hygienic conditions to avoid environmental contamination and human contagion.