No 1 - 2011
Infectious diseases 2010
Antibiotics resistance and hospital acquired infections
Denmark has hitherto enjoyed a privileged situation with a low occurrence of resistant bacteria. This situation is now seriously threatened. Part of the explanation is the increasing consumption of several broad-spectrum antibiotics (fluoroquinolones, 2nd and 3rd generation cephalosporins and carbapenems), but imported resistant bacteria and resistant bacteria transferred from foodstuffs also contribute to the observed increase in resistance.
The occurrence of resistance against cephalosporins and fluoroquinolones in K. pneumoniae and E. coli isolates has reached the levels seen in a number of Central and South European countries, EPI-NEWS 15/10 and EPI-NEWS 47/10; and for the first time ever, multi-resistant enterobacteria of the type NDM-1 have been detected in Denmark, EPI-NEWS 46/10.
Another consequence of the increased consumption is an increase in the number of Clostridium difficile infections, EPI-NEWS 18/10.
Furthermore, it seems that the occurrence of MRSA, now predominantly a community-acquired infection, is once again increasing. It is therefore encouraging that in accordance with a decision of the Ministry of the Interior and Health, the National Board of Health in 2010 established the Antibiotics Council to boost the efforts to limit antibiotics resistance, e.g. by furthering prudent use of antibiotics and avoiding overuse.
Hospital acquired infections is a related issue. They entail considerable costs for the individual patients as well as for the society. In the coming years, hospitals will be facing additional demands on efficiency in patient management and a simultaneous increase in inflow of chronic patients.
Consequently, it is essential to strengthen the national surveillance of infections acquired in health care, to advance evidence-based methods in infection hygiene and to ensure adequate resources for infectious hygiene and awareness at hospitals as well as in primary health care.
On 10 August 2010, the WHO declared the end of the 2009 influenza A(H1N1) epidemic and announced that the H1N1 influenza was expected to continue as seasonal influenza virus.
The signature of the 2009 influenza pandemic was in line with that observed during previous pandemics: Infection outside the expected influenza season, change from the normally affected age and risk groups towards younger persons and several waves of infection.
The total disease burden was, however, limited as elderly citizens were largely spared any illness and as the majority of infections had a mild clinical course, EPI-NEWS 23/10.
It is important that the experiences from the 2009 pandemic be exploited to improve future pandemic planning.
Conclusion of the catch-up programme for HPV vaccination
Since 1 January 2009, HPV vaccination has been administered to girls aged 12 years as part of the standard childhood vaccination programme. The offer covers girls born in 1996 or later.
As a special offer, girls born in 1993, 1994 and 1995 were also eligible for free vaccination in a so-called catch-up programme. This offer was valid until the end of 2010, EPI-NEWS 37/10.
The coverage of the catch-up programme ranged from 75 to 81% depending on birth year. The coverage exceeds the expected 70 % coverage, which is a very positive result. The current vaccination coverage will probably be sufficient to achieve the expected herd immunity over time.
It is essential that the girls and their parents be informed that free HPV vaccination is only offered to girls until they turn 15 years old. It is also important to maintain the currently high awareness of the HPV vaccination programme in the future and to endeavour to maintain a high vaccination coverage.
Hepatitis B, HIV and syphilis screening of pregnant women
In 2010, general screening of pregnant women for HIV and syphilis were introduced as a supplement to the hepatitis B screening already in place, EPI-NEWS 27-33/10.
The background for this decision is described in the guideline of the National Board of Health.
Selective hepatitis B, HIV and syphilis examination in pregnant women have previously proven less than optimal, as many women from the defined risk groups were not tested. Even with an optimal selective screening procedure, some pregnant women with hepatitis B, HIV or syphilis will remain unidentified because they have no known risk of these infections.
Therefore, the objective of the general screening is to identify all infected pregnant women and to institute the measures needed to avoid perinatal infection of the infant.
In the light of the favourable treatment options now associated with early diagnosis of HIV infection screening is necessary, i.e. If HIV infection is not detected in time, the risk of mother-to-child infection in Europe is 15-25 %. The risk of mother-to-child infection during pregnancy can be reduced to < 1 % through relevant and timely antiviral treatment of mother and child.
The Department of Epidemiology monitors the screening initiative in cooperation with the blood banks.
Food and water-borne infections
In 2010, the number of Salmonella infections followed a descending trend while the number of diagnosed campylobacter infections is again increasing.
The primary source of campylobacter infection is poultry or products cross-contaminated by poultry, EPI-NEWS 20-21/07 (pdf), but other sources of infection do exist.
This became evident in 2010, among others due to a drinking-water borne campylobacter outbreak in the town of Køge.
In another outbreak, a number of unfortunate triathletes presented with diarrhoea after completing part of their competition in faecally contaminated seawater following heavy showers, EPI-NEWS 42-43/10.
If climate changes take the form of more extreme weather episodes, it is probable that the future will bring more such outbreaks.
From March to September, Denmark saw a nation-wide Salmonella Typhimurium U323 outbreak affecting a total of 176 cases.
As the outbreak type was found in pork from a single slaughter house, the Danish Food Authorities quickly contained the outbreak.
Nevertheless, it continued developing and the latest incident was a cluster in which the specific source of infection was found to be a tea sausage, EPI-NEWS 42-43/10.
The outbreak illustrates just how complex salmonella management can be in practice.
(K. Mølbak, Dept. of Epidemiology)
5 January 2011