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Last updated: 10 February 2012, Volume 6, No 6 (PDF file: 370 Kb)

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HPR Home | Infection Reports | Enteric

 

Enteric infection report

 

• Enteric fever surveillance quarterly report (England, Wales and Northern Ireland): fourth quarter 2011
  

Enteric routine data reports

 

• General outbreaks of foodborne illness in humans, England and Wales:
  weeks 1-4/2012
  
• Common gastrointestinal infections, England and Wales, laboratory reports:
  weeks 1-4/2012
  
• Salmonella infections (faecal specimens) England and Wales, reports to the HPA (salmonella data set): December 2011
  
• Hospital norovirus outbreaks (England and Wales, weeks 1-4/2012) and seasonal comparisons of recent years’ norovirus laboratory reports
  

Enteric fever surveillance quarterly report (England, Wales and Northern Ireland): fourth quarter 2011

This quarterly report summarises the epidemiology of laboratory confirmed cases of typhoid and paratyphoid reported in England, Wales and Northern Ireland between October and December 2011. It includes both reference laboratory and enhanced enteric fever surveillance data. All data are provisional; final and more detailed reports will be produced on an annual basis. More information about enteric fever surveillance, including previous reports, is available on the enhanced enteric fever surveillance page of the HPA website [1].

 

National summary

In the fourth quarter of 2011, 106 laboratory confirmed cases of enteric fever were reported in England, Wales and Northern Ireland (table 1), 5% higher than the fourth quarter of 2010 and 3% above the mean (103) for the fourth quarters of 2007 to 2011 (figure 1). This higher number is mainly explained by a larger number of cases of S. Paratyphi A reported (58 in 2011 compared with 37 in 2010, 57% higher) while lower case numbers have been reported for S. Typhi and S. Paratyphi B. 23% fewer cases were caused by S. Typhi 2011 (47) compared to 2010 (61) (table 1).

Figure 1. Laboratory confirmed cases of enteric fever by organism, England, Wales and Northern Ireland: fourth quarter 2007 – 2011

Table 1. Laboratory confirmed cases of enteric fever, England, Wales and Northern Ireland: fourth quarter 2007 – 2011

Organism	Laboratory confirmed cases
	Q4 2011	Q4 2010	Q4 2009	Q 2008	Q4 2007
Salmonella Typhi	47	61	64	62	45
Salmonella Paratyphi A	58	37	42	51	36
Salmonella Paratyphi B	1	3	5	3	1
Enteric fever total	106	101	111	116	82

 

Table 2. Laboratory confirmed cases of enteric fever by organism and phage type, England, Wales and Northern Ireland: fourth quarter 2011

Phage type	S . Typhi		Phage type	S. Paratyphi A
			PT 13	21
PT E9 Var.	15		PT 4	12
PT E1	14		PT 1	9
Degr.VI	6		PT 1a	7
Untyp.VI 2	5		PT 6a	4
Untyp.VI	3		PT 2	3
PT 40	1		PT 3	1
PT A	1		Untypable	1
PT J1	1		Total	58
Untyp.VI 1	1
Total	47		Phage type	S. Paratyphi B
			Taunton	1
			Total	1

In general, S. Typhi phage types E9 var and E1 and S. Paratyphi A phage types 13, 4, and 1 occur most frequently [2].

 

Age/sex distribution

In the fourth quarter of 2011, the median age of cases was 29 years and 16% (17% for females and 19% for males) were aged 16 years and under. Males represented 57% of all cases (figure 2).

Figure 2. Laboratory confirmed cases of enteric fever by age and sex (n=106): fourth quarter 2011

Regional distribution

London reported 42% of the total cases during the fourth quarter of 2011, followed by the West Midlands (12%) and the North West and South East (10% each) (table 3).

Table 3. Laboratory confirmed cases of enteric fever by region: fourth quarter 2011

HPA Region	Q4 2011	Q4 2010	% change
London	44	49	-10.2%
West Midlands	13	11	18.2%
North West	11	11	0.0%
South East	11	8	37.5%
Yorkshire and Humber	9	6	50.0%
East	8	2	300.0%
East Midlands	6	5	20.0%
South West	4	6	-33.3%
North East	–	3	–
Wales	–	–	–
Northern Ireland	–	–	–
Total	106	101	-5.0%

Enhanced surveillance

Of 106 laboratory confirmed infections of enteric fever, 105 enhanced surveillance forms were received. One of these cases was identified as a carrier and is excluded from further analysis in this report.

Travel history

Travel history information is derived from enhanced surveillance, and where missing, supplemented by available information from laboratory forms.

In the fourth quarter, travel history was known for 104 cases (all from enhanced surveillance forms); 94/104 (90%) cases had travelled abroad and ten had not travelled. Travel-associated cases were likely to have acquired their infection in: India (45), Pakistan (34), Bangladesh (seven), Sri Lanka (five), Thailand (three), and Nepal, Bolivia, China (Tibet), Zimbabwe, Afghanistan, United Arab Emirates and Tanzania (one each). Some cases travelled to more than one country so totals above will not equal the number of total cases that travelled. Where multiple countries of travel have been stated by the case, only risk countries, as identified by the National Travel Health Network and Centre [3], were included for analysis. If a case has travelled to multiple risk countries each country is counted individually. India and Pakistan continue to be the most frequently reported countries of travel throughout the year (figure 3).

Figure 3. Laboratory-confirmed cases of enteric fever, England, Wales and Northern Ireland by country of travel: fourth quarter 2007 – 2011

 

Reason for travel

Figure 4. Laboratory-confirmed cases of enteric fever that have travelled abroad (n=92) by reason for travel: fourth quarter 2011

 

Of the 94 cases that had travelled abroad, reason for travel was known for 92; 80% of cases travelled to visit friends and relatives mainly in the Indian sub continent, 13% travelled abroad for a holiday and 3% were foreign visitors to the UK (figure 4).

Non-travel-associated cases

Ten cases in the fourth quarter had not travelled abroad within 28 days of developing symptoms. Three of these cases were associated with three different clusters. The first of these cases had contact with a family member who had travelled to Bangladesh and was confirmed to have S. Typhi, PT E9 Var; the same organism was confirmed in the non-travel case. The second was an acquainted contact of a confirmed case that had travelled to Pakistan. The third had a family link with another case that also had no travel history. The other seven cases had no links to known cases or travellers from endemic countries. A definite source was not identified for any of these cases.

Data sources and acknowledgements

Data were collated and analysed by the Travel and Migrant Health Section, Health Protection Services, Colindale. Laboratory data were provided by Laboratory of Gastrointestinal Pathogens, Microbiology Services, Colindale. Other surveillance data were provided by Environmental Health Officers and local health protection colleagues in the HPA through enteric fever enhanced surveillance.

References

1. HPA website. Enhanced surveillance of enteric fever. Available at: http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/TravelHealth/
GeneralInformation/trav30Enhancedsurveillanceofentericfever/

2. Health Protection Report. Archived enteric routine data reports. Available online at: http://www.hpa.org.uk/hpr/archives/Infections/2011/enteric11.htm

3. National Travel Health Network and Centre (NaTHNaC) website. Available at: http://www.nathnac.org/

General outbreaks of foodborne illness in humans, England and Wales: weeks1-4/2012

Preliminary information has been received about the following outbreaks.

Health Protection Unit	Organism	Location of food prepared or served	Month of outbreak	Number ill	Cases positive	Suspect vehicle	Evidence
West Midlands North	Campylobacter	Restaurant	Jan-12	20	2	Not known	n/a
National outbreak	Salmonella Newport	National	Jan-12	42	30	Water melon	D and M

D = Descriptive epidemiological evidence: suspicion of a food vehicle in an outbreak based on the identification of common food exposures, from the systematic evaluation of cases and their characteristics and food histories over the likely incubation period by standardised means (such as standard questionnaires) from all, or an appropriate subset of, cases.
M = Microbiological evidence: detection of a causative agent in a food vehicle or its component or in the food chain or its environment combined with detection in human cases, or clinical symptoms and an onset of illness in outbreak cases compatible with / pathognomonic to the causative agent identified in the food vehicle or its component or in the food chain or its environment.

Common gastrointestinal infections, England and Wales, laboratory reports: weeks1-4/2012

Laboratory reports	Number of reports received				Total reports	Cumulative total to
	1/12	2/12	3/12	4/12	1-4/12	4/12	4/11
Campylobacter	803	889	892	815	3399	3399	3426
Escherichia coli O157 *	6	7	7	6	26	26	41
Salmonella †	92	103	57	8	260	260	454
Shigella sonnei	17	16	19	3	55	55	86
Rotavirus	139	184	238	303	864	864	839
Norovirus	270	325	272	234	1101	1101	993
Cryptosporidium	38	37	27	32	134	134	140
Giardia	74	79	74	70	297	297	250

*Vero cytotoxin–producing isolates (data from the HPA Laboratory of Gastrointestinal Pathogens (LGP).
† Data from LGP.

Salmonella infections (faecal specimens) England and Wales, reports to the HPA (salmonella data set): December 2011

Details of 381 serotypes of salmonella infections recorded in December are given in the table below. In January 2012, 262 Salmonella infections were recorded.

Organism	Cases: December 2011
S. Enteritidis PT4	7
S. Enteritidis (other PTs)	63
S. Typhimurium	98
S. Virchow	4
Others (typed)	209
Total salmonella (provisional data)	381

Figures quoted from the Health Protection Agency salmonella data set are for isolates confirmed and typed by Laboratory of Gastrointestinal Pathogens (LGP).

Hospital norovirus outbreaks (England and Wales, weeks1-4/2012) and seasonal comparisons of recent years’ norovirus laboratory reports

The norovirus outbreaks in hospitals reporting scheme recorded 172 outbreaks occurring between weeks 1 and 4 2012. Of these outbreaks 124 (72%) reported ward closures or restriction to admissions and 116 (67%) were reported as laboratory confirmed norovirus outbreaks. Last year from week 1 (January 2011) to week 52 (December 2012) 1286 outbreaks have been reported. Seventy-one percent (913) of reported outbreaks resulted in ward closures or restrictions to admissions and 62 percent (802) were laboratory confirmed as due to norovirus.

Suspected and laboratory-confirmed reported norovirus outbreaks in hospitals, with regional breakdown: outbreaks occurring in weeks 1-4/2012

	Outbreaks between weeks 1-4/2012			Total outbreaks 01-52/11
	Outbreaks	Ward closure	Lab-confirmed	Outbreaks	Ward closure	Lab-confirmed
East of England	–	–	–	20	20	19
East Midlands	20	9	11	82	69	64
London	9	9	8	38	30	28
North East	16	12	13	117	85	70
North West	25	20	19	150	82	86
South East	34	27	29	173	135	115
South West	32	27	26	340	287	229
West Midlands*	16	14	6	125	68	29
Yorkshire & Humberside	20	6	4	241	137	162
Total	172	124	116	1286	913	802

* Information on hospital outbreaks in this region is now supplied from the West Midlands Region’s own reporting scheme and is less complete for data on ward closures and lab confirmation.

 

Seasonal comparison of laboratory reports of norovirus (England and Wales)

The number of laboratory reports of norovirus from week 27 2011 to week 04 2012 is 3569. The total number of laboratory reports for the same period in 2010/2011 was 2971, which is a 20 percent increase †. The number of laboratory reports is now around the average for this time of year. The number of laboratory reports in the most recent weeks will increase as further reports are received.

† The norovirus season runs from July to June (week 27 in year one to week 26 in year two) in order to capture the winter peak in one season.

Figure 1. Seasonal comparison of laboratory reports of norovirus (England and Wales)

 

Figure 2. Current weekly norovirus laboratory reports compared to weekly mean reports 2006-2010