Risk of Antimicrobial Resistance from Birds

6 December 2017

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For Written Answer on : 06/12/2017 

Question Number(s): 188, 189, 195, 196, 197 & 198 Question Reference(s): 52188/17 Written, 52189/17 Written, 52231/17 Written, 52232/17 Written, 52233/17 Written, 52234/17 Written 

Department: Health 

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QUESTION 

* 188. To ask the Minister for Health further to parliamentary question numbers 271 and 272 of 17 October 2017, if the one health approach to tackling antimicrobial resistance (AMR) encompassing all sectors means that the current and evolving risk of AMR contamination associated with urban gulls will be monitored and addressed by the recently established National Interdepartmental AMR Consultative Committee in view of the launch of iNAP on 25 October 2017; and if he will make a statement on the matter.

- Brendan Ryan T.D.

For WRITTEN answer on Wednesday, 6th December, 2017.

* 189. To ask the Minister for Health if such current and emerging associations (details supplied) will be monitored and addressed by the recently established national interdepartmental AMR consultative committee; and if he will make a statement on the matter.

- Brendan Ryan T.D.

For WRITTEN answer on Wednesday, 6th December, 2017.

Details Supplied: email sent to dept @ 12.37 if he is aware of the following recent European scientific studies directly associating urban gulls with Carbapenemase Producing Enterobacteriaceae (CPE), the AMR variant signalled in iNAP as the one of most concern,

 

REPLY 

 

The HSE-Health Protection Surveillance Centre (HPSC) is a specialist agency for the surveillance of communicable diseases. It works in partnership with health service providers and similar organisations in Ireland and around the world, to provide the best possible information for the control and prevention of infectious diseases. The roles of the HPSCinclude providing timely information and independent advice, carrying out disease surveillance, epidemiological investigation and related research and training. 

Earlier this year the HPSC undertook an investigation to determine if gulls posed a potential infectious risk and to attempt to quantify this in the most valid manner.  The main focus of investigation was an examination of the potential for transmission from gulls to man, of infectious disease. An extensive review of the relevant international literature on the evidence for transmission of infectious disease from gulls to man indicated that, although disease carriage is relatively common amongst such birds, there is very little evidence of disease transmission to humans and that wild birds play a limited role in human infectious disease. 

About 5% of gulls are infected with Salmonella.  This is a lower prevalence than many other common wild birds.  For example, amongst starlings and house sparrows, a number of studies agree that the prevalence of carriage of various pathogens is about is in the range of 24% for Salmonella, 4% for Campylobacter and 24% Clostridium perfringens.  About 20% of starlings carry E.coli and the same levels are seen in crows.  Levels of these pathogens are even higher in long distance migratory birds. 

With regard to antibiotic resistant pathogens, in general about 10-15% of isolates carried by wild birds, are resistant to the common (and not so common antibiotics).  Transmission of antimicrobial resistance (AMR) by wildbirds is a potential health issue, but it has its greatest potential for impact when the birds acquire these AMR pathogens in countries where there are high levels of AMR.  These can be carried long distances by far-reaching migratory wild birds.  Gulls do not migrate very far, and so tend to be infected with local pathogens. 

A review of 10 years Irish national infectious disease data was carried out to determine how many cases of any infectious disease (but particularly instances of gastrointestinal disease caused by Salmonella and Campylobacter) could be attributed to contact with birds. The aim was to determine the proportion of human infectious disease cases in which wild birds (including gulls) were associated. The results of this investigation showed that in that ten-year period, there were barely a handful of infectious disease cases that could be explained by bird contact.  Between 2006 and 2016, there were just three cases of salmonellosis (two of these mentioned contact with caged, pet birds) and a further two cases of campylobacteriosis (one of which mentioned proximity to gulls). These were suggestive of association but not evidence of cause.  Moreover, there were no outbreaks of human disease over the same 10 year period in which gulls (or any other wild birds) had been implicated as the cause of an outbreak of infectious disease, or even a contributory factor. 

Over the last 10 years there have been in total in Ireland, about 25,500 reported cases of Campylobacter and 3,900 cases of Salmonella.  That investigation found that, of our salmonellosis cases, 0.06% and of our campylobacteriosis cases, 0.012% mentioned some form of bird contact, though not necessarily causative.  In other words, cases of these diseases that even mentioned birds as possible risk factors are extremely uncommon.  

The information that gulls are colonised with bacteria which demonstrate varying levels of antimicrobial resistance does not add to the negligible risks of transmission from gulls to humans. Just because these are AMR pathogens, this does not alter their ability to be spread from these birds to humans and AMR pathogens are just as unlikely as non-AMR pathogens to be spread in this manner. Moreover, among wild birds, gulls would seem to have a lower propensity (as evidenced by their lower rate of carriage) to carry these pathogens than other, far more numerous species, such as crows, starlings and sparrows. 

In Public Health, health threats are prioritised using a number of parameters (severity of disease, potential for transmission, numbers of cases of illness).  Diseases that have such features as severe of illness, ready transmissibility, or high numbers of cases then become priorities for Public Health interventions such as control and prevention.  Iit is evident that there are extremely low numbers of cases of diseases spread from gulls to humans in this manner and that this is an extremely uncommon way in which humans can acquire these diseases.  It this was a common or significant mode of transmission there would have been considerably greater numbers of these diseases over the years in which gulls as a potential source of infection were mentioned and there would been evidence of outbreaks of illness that could be validly explained by gull contact. 

The available evidence, while indicating that gulls and other wild birds do carry potentially harmful pathogenic bacteria, does not indicate that they transmit these microbes to any significant extent, or in any meaningful amount, to humans despite these birds having been documented as carrying and excreting these bacteria, in close proximity to humans, for many decades. 

With regard to the Intradepartmental AMR Consultative Committee which was launched in November 2014. This committee advised on the development Ireland’s National Action Plan on Antimicrobial Resistance (iNAP) which was launched October 25th 2017. An implementation plan for iNAP is currently being drafted.