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Summary We investigated episodes of suspected highly pathogenic avian influenza (HPAI)‐like illness among 12 meat duck flocks in two districts in Tien Giang province (Mekong Delta, Vietnam) in November 2013. In total, duck samples from 8 of 12 farms tested positive for HPAI virus subtype A/haemagglutinin 5 and neuraminidase 1 (H5N1) by real‐time RT‐PCR. Sequencing results confirmed clade of 2.3.2.1.c as the cause of the outbreaks. Most (7/8) laboratory‐confirmed positive flocks had been vaccinated with inactivated HPAI H5N1 clade 2.3.4 vaccines

A previous limited study demonstrated that Mycobacterium tuberculosis isolates with a mutation at amino-acid position 315 of katG (Delta315) exhibited high-level resistance to isoniazid and were more frequently resistant to streptomycin. In the present study, isoniazid-resistant M. tuberculosis isolates from 8,332 patients in The Netherlands (1993-2002) were screened for the Delta315 mutation. Isoniazid resistance was found in 592 (7%) isolates, of which 323 (55%) carried Delta315. IS6110 restriction fragment length polymorphism analysis showed that Delta315 isolates occurred in clusters, suggesting recent transmission, at the same frequency as isoniazid-susceptible isolates. In contrast, other isoniazid-resistant isolates clustered significantly less frequently. Delta315 isolates were high-level isoniazid-resistant, streptomycin-resistant and multidrug-resistant significantly more often, and may have a greater impact on public health, than other isoniazid-resistant isolates.

A mutation (CCG→CTG [Arg→Leu]) in codon 463 of katG (catalase peroxidase) of Mycobacterium tuberculosis has been found in isoniazid (INH)-resistant strains. A PCR restriction endonuclease analysis to detect this mutation was applied to 395 M. tuberculosis isolates from patients in The Netherlands. The proportion of isolates with a detectable mutation was 32% (32 out of 100) and 29% (85 out of 295) among INH-susceptible isolates and INH-resistant or -intermediate isolates, respectively. Sequencing of five INH-susceptible isolates with such mutations showed that all five had the Arg463Leu mutation. We conclude that the Arg463Leu mutation of katG of M. tuberculosis is not a reliable indicator of INH resistance.

Unlike other immunoglobulin G (IgG) subclasses, IgG4 antibodies in plasma have been reported to be functionally monovalent. In this paper we show that the apparent monovalency of circulating IgG4 is caused by asymmetry of plasma IgG4. A large fraction of plasma IgG4 molecules have two different antigen-binding sites, resulting in bispecificity. Sera from patients with IgG4 antibodies to both house dust mite and grass pollen induced cross-linking of Sepharose-bound grass pollen antigen to radiolabelled house dust mite allergen Der p I. This bispecific binding activity was not observed in sera with IgG4 antibodies to either grass pollen or house dust mite exclusively. Depletion of IgG4 antibodies resulted in disappearance of the bispecific activity. By size exclusion chromatography we excluded the possibility that bispecific activity was caused by aggregation of IgG4 antibodies. These results indicate that circulating (polyclonal) IgG4 antibodies have two different antigen-binding sites and therefore are functionally monovalent antibodies.

To the Editor: Oseltamivir-resistant infection with the 2009 pandemic influenza A (H1N1) virus has so far been described only rarely and is conferred by the H275Y substitution in the neuraminidase enzyme.1 Only 3 of the 32 patients with oseltamivir-resistant infection reported on as of this writing were not receiving oseltamivir when the resistant viruses were detected, and ongoing community transmission has not yet been shown.1 However, the emergence of oseltamivir-resistant 2009 H1N1 influenza remains a grave concern, since widespread oseltamivir resistance has been observed in seasonal H1N1. This resistance was unrelated to selective drug pressure, and the H275Y substitution did . . .

A 31-year-old man with no relevant medical history encountered a white, ribbon-shaped object, 15 cm long and approximately 1 cm wide, in his faeces. It turned out to be Diphyllobothrium latum, a tapeworm that has fish as the intermediate host. The patient had eaten raw fish and shellfish during a holiday in Brazil 5 months before. He recovered after a single dose of praziquantel.

Metabolic events were studied in electrically stimulated in vivo quadriceps muscle of young male rats during maximal contractions under anaerobic conditions and during aerobic recovery. Up to about 6 seconds there was a rapid fall in creatine phosphate (CP) and ATP with initial rates of 5.5 and 0.4 μmoles.g wet weight−1.sec−1, respectively. During the same period the lactate concentration increased directly from the beginning of the exercise with an initial rate of 1.0 μmoles.g wet weight−1.sec−1. From these results an anaerobic power of 7.4 μmoles energy-rich compounds.g wet weight−1.sec−1 could be calculated. After 6 seconds up to 30 seconds the CP and ATP concentrations stayed constant at 20% and 70% of their resting values, respectively. An observed decrease in the total adenine nucleotide (ANP) concentration of 1.3 μmoles.g wet weight in the first 6 seconds of the exercise coincides with an concomitant increase in inosine monophosphate (IMP). Measurements of the force showed a decrease of 5% per second starting after about 4 seconds. Recovery under aerobic conditions from a 15 second period of maximal isometric exercise was slow; after 10 minutes resting values were not reached. Experiments, in which adult rats were heavily trained on a motor-driven treadmill for 6 weeks, 5 days a week, showed no differences in anaerobic power and the course of the force developed, although a marked increase in exercise capacity could be demonstrated. Comparison of the metabolic events in young and adult rats at rest and during maximal electric stimulation showed: 1. a 25% lower sum of creatine phosphate + creatine in the young group mainly due to a lower creatine concentration. 2. no inosine monophosphate production from adenine nucleotides in the first 6 seconds and only a slight increase at 15 and 30 seconds could be demonstrated in the adult group. This means that under our experimental conditions correct concentrations of ATP, ADP and AMP are attained without the action of AMP deaminase.