Risk-based surveillance for avian influenza control along poultry market chains in South China: The value of social network analysis

Over the past two decades, the poultry sector in China went through a phase of tremendous growth as well as rapid intensification and concentration. Highly pathogenic avian influenza virus (HPAIV) subtype H5N1 was first detected in 1996 in Guangdong province, South China and started spreading throughout Asia in early 2004. Since then, control of the disease in China has relied heavily on wide-scale preventive vaccination combined with movement control, quarantine and stamping out. This strategy has been successful in drastically reducing the number of outbreaks during the past 5years. However, HPAIV H5N1 is still circulating and is regularly isolated in traditional live bird markets (LBMs) where viral infection can persist, which represent a public health hazard for people visiting them. The use of social network analysis in combination with epidemiological surveillance in South China has identified areas where the success of current strategies for HPAI control in the poultry production sector may benefit from better knowledge of poultry trading patterns and the LBM network configuration as well as their capacity for maintaining HPAIV H5N1 infection. We produced a set of LBM network maps and estimated the associated risk of HPAIV H5N1 within LBMs and along poultry market chains, providing new insights into how live poultry trade and infection are intertwined. More specifically, our study provides evidence that several biosecurity factors such as daily cage cleaning, daily cage disinfection or manure processing contribute to a reduction in HPAIV H5N1 presence in LBMs. Of significant importance is that the results of our study also show the association between social network indicators and the presence of HPAIV H5N1 in specific network configurations such as the one represented by the counties of origin of the birds traded in LBMs. This new information could be used to develop more targeted and effective control interventions.     

Salmonella enterica serovar Kentucky recovered from human clinical cases in Maryland,USA (2011–2015)

Salmonella Kentucky is among the most frequently isolated S. enterica serovars from food animals in the United States. Recent research on isolates recovered from these animals suggests there may be geographic and host specificity signatures associated with S. Kentucky strains. However, the sources and genomic features of human clinical S. Kentucky isolated in the United States remain poorly described. To investigate the characteristics of clinical S. Kentucky and the possible sources of these infections, the genomes of all S. Kentucky isolates recovered from human clinical cases in the State of Maryland between 2011 and 2015 (n = 12) were sequenced and compared to a database of 525 previously sequenced S. Kentucky genomes representing 12 sequence types (ST) collected from multiple sources on several continents. Of the 12 human clinical S. Kentucky isolates from Maryland, nine were ST198, two were ST152, and one was ST314. Forty‐one per cent of isolates were recovered from patients reporting recent international travel and 58% of isolates encoded genomic characteristics similar to those originating outside of the United States. Of the five isolates not associated with international travel, three encoded antibiotic resistance genes conferring resistance to tetracycline or aminoglycosides, while two others only encoded the cryptic aac(6′)‐Iaa gene. Five isolates recovered from individuals with international travel histories (ST198) and two for which travel was not recorded (ST198) encoded genes conferring resistance to between 4 and 7 classes of antibiotics. Seven ST198 genomes encoded the Salmonella Genomic Island 1 and substitutions in the gyrA and parC genes known to confer resistance to ciprofloxacin. Case report data on food consumption and travel were, for the most part, consistent with the inferred S. Kentucky phylogeny. Results of this study indicate that the majority of S. Kentucky infections in Maryland are caused by ST198 which may originate outside of North America.     

Genetic analysis of Aequipecten opercularis and Mimachlamys varia (Bivalvia: Pectinidae) in several Atlantic and Mediterranean localities, revealed by mitochondrial PCR-RFLPs: a preliminary study

Aequipecten opercularis (Queen scallop) and Mimachlamys (Chlamys) varia (Black scallop) are important natural resources occurring in Atlantic and Mediterranean coasts. To develop an optimal sustainable exploitation plan, it is important to study the genetic structure of the different populations. In this study, we used polymerase chain reaction‐restriction fragment length polymorphisms for the determination of the genetic variation and population structure of these two species in different localities. Ten composite haplotypes were generated for A. opercularis and 15 haplotypes for M. varia. Of these, six and four were unique respectively. The analysis of the distribution of the different haplotypes between the localities showed no clear evidence of subdivision in A. opercularis, while in M. varia the results indicated that the two localities analysed should be managed as separate stocks.     

Retrobulbar teratoma causing exophthalmos in a cat

A 3-year female-neutered domestic shorthair cat presenting with exophthalmos and an ipsilateral subzygomatic soft tissue mass lesion is described. Magnetic resonance imaging of the mass was performed followed by complete surgical excision. The mass was determined to be a retrobulbar teratoma and complete resection was curative. Teratomas are rare germ-cell tumours that uncommonly form in extragonadal sites. A retrobulbar location has not been previously reported in the cat and should be considered a rare cause of exophthalmos in this species.