Interspecies Transmission of Swine Influenza A Viruses and Human Seasonal Vaccine-Mediated Protection Investigated in Ferret Model

We investigated the infection dynamics of 2 influenza A(H1N1) virus isolates from the swine 1A.3.3.2 (pandemic 2009) and 1C (Eurasian, avian-like) lineages. The 1C-lineage virus, A/Pavia/65/2016, although phylogenetically related to swine-origin viruses, was isolated from a human clinical case. This strain infected ferrets, a human influenza model species, and could be transmitted by direct contact and, less efficiently, by airborne exposure. Infecting ferrets and pigs (the natural host) resulted in mild or inapparent clinical signs comparable to those observed with 1A.3.3.2-lineage swine-origin viruses. Both H1N1 viruses could infect pigs and were transmitted to cohoused ferrets. Ferrets vaccinated with a human 2016-17 seasonal influenza vaccine were protected against infection with the antigenically matched 1A pandemic 2009 virus but not against the swine-lineage 1C virus. Our results reaffirm the need for continuous influenza A virus surveillance in pigs and identification of candidate human vaccine viruses.

Transmission dynamics between infected waterfowl and terrestrial poultry: Differences between the transmission and tropism of H5N8 highly pathogenic avian influenza virus (clade 2.3.4.4a) among ducks, chickens and turkeys

H5N8 highly-pathogenic avian influenza viruses (HPAIVs, clade 2.3.4.4) have spread globally via migratory waterfowl. Pekin ducks infected with a UK virus (H5N8-2014) served as the donors of infection in three separate cohousing experiments to attempt onward transmission chains to sequentially introduced groups of contact ducks, chickens and turkeys. Efficient transmission occurred among ducks and turkeys up to the third contact stage, with all (100%) birds becoming infected. Introduction of an additional fourth contact group of ducks to the turkey transmission chain demonstrated retention of H5N8-2014's waterfowl-competent adaptation. However, onward transmission ceased in chickens at the second contact stage where only 13% became infected. Analysis of viral progeny at this contact stage revealed no emergent polymorphisms in the intra-species (duck) transmission chain, but both terrestrial species included changes in the polymerase and accessory genes. Typical HPAIV pathogenesis and mortality occurred in infected chickens and turkeys, contrasting with 5% mortality among ducks.

No abnormal prion protein detected in the milk of cattle infected with the bovine spongiform encephalopathy agent

Milk specimens were collected from lactating cows that had previously been challenged with bovine spongiform encephalopathy (BSE)-infected brain at 4–6 months of age. One group of 10 animals received a single oral dose of 100 g, a second group received 1 g and the third was made up of unexposed controls. The cows were inseminated artificially, and calved at approximately 2 years of age and annually thereafter. Milking was done within the first week following calving and at 10-weekly intervals during the lactation period. Specimens were centrifuged to obtain a fraction enriched for somatic cells and these fractions were analysed for disease-associated, abnormal prion protein (PrPBSE) by using a modified commercial BSE ELISA and a different confirmatory assay. No abnormal prion protein has so far been identified in the cell fraction of milk from cattle incubating BSE by using these methods at their limits of detection.

Gastroentological investigations

In this fourth article in the Concepts in Anatomy series, Anne-Marie Ramsay joins John Clancy and Andrew McVicar in examining the upper and lower gastrointestinal tract and identifies some common homeostatic imbalances. Diagnostic tests for detecting abnormalities are described, highlighting the importance of the nurse's role in caring for the patient throughout these procedures. This series is based on Physiology and Anatomy, a homeostatic approach, 2nd ed, John Clancy and Andrew McVicar (eds), Edward Arnold, London, 1995, currently in print.

Myalgic encephalomyelitis--a persistent enteroviral infection?

Myalgic encephalomyelitis is a common disability but frequently misinterpreted. Amongst 6,000 patients referred for general microbiological diagnosis between 1975 and 1987, 420 cases were recognized. Coxsackie B neutralization tests, in 205 of these, demonstrated significant titres in 103/205 (50%), while of 124 additionally investigated for enteroviral IgM, 38/124 (31%) were positive. This illness is distinguished from a variety of other post-viral states by an unique clinical and epidemiological pattern characteristic of enteroviral infection. Prompt recognition and advice to avoid over-exertion is mandatory. Routine diagnosis, specific therapy and prevention, await further technical advances.

Exploring the benefits of medical record automation

During the past two years University Health Center, Burlington, VT., has been involved in the development and testing of a problem-oriented automated medical record. Although the achievements to date have largely been predicated on the effective use of the sophisticated computer technology, the system's basic premise and foremost requirement remains simply to improve the collection and presentation of patient clinical information.

Clinical and biochemical findings in ten patients with benign myalgic encephalomyelitis

Ten patients in whom the clinical findings were consistent with the syndrome variously described as 'benign myalgic encephalomyelitis', 'epidemic neuromyasthenia', 'Royal Free disease' and 'Icelandic disease' were investigated for blood levels of myoglobin and various enzymes. Although there is no clinical resemblance between the two diseases, the biochemical pattern bears a close similarity to that found in Duchenne muscular dystrophy (DMD) though differing sharply in that no rise in creatinine kinase levels was found. These findings are discussed with particular reference to recent suggestions that the permeability of cell membranes may be impaired by changes in intracellular energy mechanisms.

Effects of phosphate limitation of growth on the cell-wall and lipid composition of Saccharomyces cerevisiae

The phosphorus content of phosphate-limited Saccharomyces cerevisiae was only 71% of that of non-limited yeast. Walls prepared from phosphate-limited cells contained slightly less phosphorus than control walls. No evidence was obtained for the presence in these walls of uronic acid or succinyl residues. The carbohydrate content of walls of phosphate-limited yeast was less than that of non-limited walls, and this was reflected in a decreased glucan content. There was only a slight decrease in glucosamine content while the protein content increased. The major change in the lipid composition of phosphate-limited yeast was a decrease in both sterol esters and triacylglycerols. There was a decrease in total lipid content, but increased production of phosphatidylethanolamine and phosphatidylcholine. The phosphatidylserine content was decreased. These results suggest that there are fewer intracellular low-density vesicles in phosphate-limited yeast.

'Epidemic neuromyasthenia' 1955-1978

A record of fifty-three patients admitted to the Infectious Diseases Department of the Royal Free Hospital between April 1955 and September 1957 suffering from 'epidemic neuromyasthenia' establishes the fact that the condition was endemic in the general population before, during and after the outbreak among the staff of the hospital. A further outbreak occurred in North Finchley between 1964 and 1967 and sporadic new cases are still being encountered. The majority of these patients show evidence of involvement of the central and sympathetic nervous systems and the reticulo-endothelial system. Abnormal muscular fatigability is the dominant clinical feature and it is suggested that mitochondrial damage may provide an explanation for this phenomenon. Enzyme tests carried out in seven cases show pathologically high levels of lactic dehydrogenase, and glutamic oxalo-acetic transaminase. A follow-up study suggests that there is one group of patients that recovers completely or nearly completely, a second that recovers but is subject to relapses and a third that shows little or no recovery, these patients remaining incapacitated.

Aeromonas hydrophila sepsis in a patient undergoing hemodialysis therapy

Aeromonas hydrophila septicemia complicated by a generalized cutaneous vasculitis developed in a patient receiving home hemodialysis therapy. Because the Aeromonas organism is found in many natural water sources, the possibility that this patient's hemodialysis system became contaminated was explored. Although cultures from the patient's home environment showed no Aeromonas sp, the possibility still exists that the site of contamination was in the dialysis system.