Monthly Infectious Diseases Surveillance Report

Transcription

1 June 2015 Monthly Infectious Diseases Surveillance Report Volume 4, Issue 6 The Monthly Infectious Diseases Surveillance Report is produced by Public Health Ontario (PHO) for the public health community of Ontario. We welcome feedback by to: SurveillanceServices@oahpp.ca. Past issues and additional information are available online. In Focus... 1 Significant Reportable Disease Activity... 7 Infectious Disease Activity in Other Jurisdictions... 8 Recently Discontinued Enhanced Surveillance Directives... 8 Appendix Reportable Diseases IN FOCUS Campylobacteriosis Campylobacter is the most commonly reported cause of bacterial gastroenteritis in humans worldwide, 1-3 including Ontario. 4-7 Campylobacter infection, or campylobacteriosis, is characterized by diarrhea (sometimes bloody), abdominal pain (mild to severe), fever, malaise, nausea, and, in some cases, vomiting. The Campylobacter species C. jejuni and C. coli are most commonly associated with campylobacteriosis. There have been 15 other species of Campylobacter identified, including C. lari, C. fetus, and C. upsaliensis. 1,2

2 Campylobacteriosis is typically a self-limiting illness that resolves in 5-7 days; 2 however, in some cases, symptoms may be experienced for up to two weeks. 1 As well, 5-10% of patients may experience a relapse of their initial illness. 2 Populations at higher risk of campylobacteriosis are males, children under the age of five, and the immunocompromised. 1 While most cases of campylobacteriosis are mild, in some cases they can be fatal, particularly among the very young, elderly, and immunocompromised. 3 Campylobacteriosis can cause severe post-infection complications such as Guillain-Barré syndrome (GBS), which can lead to paralysis of the arms and legs and can cause respiratory and neurological dysfunction. Other post-infection complications include reactive arthritis which can last for months, and irritable bowel syndrome. These post-infection complications are rare, and are more likely to occur among persons who are immunocompromised. 1-3,8 The incubation period of campylobacteriosis is generally 2 to 5 days but can range from 1 to 10 days, depending on the infectious dose. The level of exposure necessary to cause illness in humans can be as low as 500 organisms. Following infection, individuals can shed the pathogen for 2 to 7 weeks; however, person-to-person transmission is not a common source of infection. 1 A variety of warm-blooded animals can be reservoirs for Campylobacter, particularly cattle and poultry. 1-3 Puppies, kittens, swine, sheep, rodents, and birds, are also potential sources of Campylobacter. Humans can become infected with Campylobacter through direct contact with these animals, consuming undercooked meat and poultry, consuming unpasteurized dairy products, or drinking water that has been contaminated with the pathogen. 1,2,8 In Canada, it is estimated that Campylobacter infections are most commonly transmitted to humans through food. 9 In 2014, a total of 3,781 confirmed cases of campylobacteriosis were reported in Ontario, which corresponds to an incidence rate of 27.6 cases per 100,000 population. Between 2005 and 2014, provincial incidence rates of campylobacteriosis remained relatively stable (Figure 1) and consistent with rates at the national level in Canada ( ). At the provincial level, no outbreaks of campylobacteriosis were reported in Ontario between 2005 and Increases in campylobacteriosis are generally seen in warmer months, 1-3 with the greatest proportion of Ontario cases in 2014 occurring in June (11%), July (14%), August (12%), and September (12%) (Figure 2). The number of cases observed in the fall (September to November) of 2014 were slightly higher than what would be expected based on historical five-year averages. Monthly Infectious Diseases Surveillance Report Page 2 of 11

3 Number of Cases Rate per 100,000 Population Figure 1. Reported number of cases and incidence rate (per 100,000 population) of confirmed cases of campylobacteriosis: Ontario, Cases Ontario Rate Canada Rate Episode Year 0.0 Data sources: Ontario cases: Ontario Ministry of Health and Long-Term Care (MOHLTC), integrated Public Health Information System (iphis) database, extracted by Public Health Ontario (PHO) [2015/05/21]. Ontario population [ ]: Population Estimates , MOHLTC, IntelliHEALTH Ontario, extracted [2015/05/22]. Ontario population [2014]: Statistics Canada. Table Estimates of population, by age group and sex for July 1, Canada, provinces and territories, annual (persons unless otherwise noted), CANSIM (database), extracted [ ]. Canadian rates: Public Health Agency of Canada (PHAC), Canadian Notifiable Disease Section, received by PHO [2013/12/16]; national data available up to Monthly Infectious Diseases Surveillance Report Page 3 of 11

4 Number of Cases Figure 2. Annual number and five-year historical average of confirmed cases of campylobacteriosis: Ontario, Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Cases Avg ( ) Episode Month Ontario cases: MOHLTC, iphis database, extracted by PHO [2015/05/21]. Of the 3,781 confirmed cases of campylobacteriosis reported in 2014, 2,117 cases (56%) were male. Cases ranged in age from less than one year to 103 years of age, with a median age of 39 years; the median ages for males and females were approximately equal. Rates of campylobacteriosis were highest among males four years of age and younger (157 cases, 45.2 per 100,000 population). The second highest rate was among males aged (199 cases, 41.4 per 100,000 population). These finding are consistent with other observations that males and children younger than five years are at higher risk for campylobacteriosis. 1-3,8 Among females, the highest incidence rate of campylobacteriosis was reported among older adults 80 years of age and older (132 cases, 33.7 per 100,000 population). Among public health units (PHUs), the highest rates of campylobacteriosis in 2014 were reported in Perth District (50 cases, 64.2 per 100,000 population), Huron County (28 cases, 47.9 per 100,000 population), and Grey Bruce (71 cases, 43.6 per 100,000 population). Nine other PHUs reported incidence rates in 2014 that were above the provincial average of 27.6 per 100,000 population: Wellington-Dufferin-Guelph; Oxford County; York Region; Toronto; Haldimand-Norfolk; Haliburton, Kawartha, Pine Ridge; Eastern Ontario; Niagara Region; and Waterloo Region. Risk factors between urban and rural PHUs differ; in particular, contact with animals is reported more frequently in rural settings. 7 Risk factors were reported for 2,356 of the 3,781 (62%) campylobacteriosis cases in The most commonly reported risk factor was contact with animals, such as pets, farm animals, or petting zoos (888/2,356, 38%). Other risk factors reported by 10% or more of cases were: travel outside of Ontario in the 10 days before disease onset (717/2,356, 30.4%), recreational water contact (348/2,356, 15%), Monthly Infectious Diseases Surveillance Report Page 4 of 11

5 consumption of potentially contaminated water (245/2,356, 10%), and consumption of raw or undercooked poultry and/or poultry products (239/2,356, 10%). There were 169 cases (5%) who reported an immunocompromising health condition as a medical risk factor. Complications were rare, with one case (0.03%) of GBS reported. Two-hundred and thirteen cases (6%) reported hospitalization, and one case (0.03%) reported campylobacteriosis as the contributing but not the underlying cause of death. To reduce the risk of acquiring campylobacteriosis from pets and other animals, hands should be carefully washed after contact with animals, and children should be assisted with handwashing. It is important to avoid eating or putting hands into the mouth after touching animals until hands are properly washed. If soap and water is not available, a 70% alcohol-based hand sanitizer should be used. When travelling internationally it is important to take precautions with food and water, such as: ensuring foods are cooked well and served hot; avoiding street vendors; drinking only boiled, disinfected, or bottled water; consuming fruits and vegetables washed with potable water or peeled yourself; and avoiding inhaling or swallowing water while bathing, showering or swimming. 10 At home, prevention strategies include appropriate food handling practices such as cooking foods to the correct internal temperatures (i.e., at least 74 C for poultry pieces, 82 C for whole poultry, and 63 C for beef), 11 ensuring milk and dairy products are pasteurized, and avoiding cross-contamination between raw and cooked foods. It is also important to ensure that drinking and recreational water are safe for use. Monthly Infectious Diseases Surveillance Report Page 5 of 11

6 References 1. Heymann DL, editor. Control of communicable diseases manual. 20 th ed. Washington: American Public Health Association; Fitzgerald C. Campylobacter. Clin Lab Med. 2015;35(2): World Health Organization. Campylobacter fact sheet no Geneva, Switzerland: WHO Media Centre; 2011 [cited 2015 May 15]. Available from: 4. Thomas K, Murray R, Flockhart L, Pintar K, Pollari F, Fazil A, et al. Estimates of the burden of foodborne illness in Canada for 30 unspecified pathogens and unspecified agents, circa Foodborne Pathog Dis [cited 2015 May 15];10(7): Vrbova L, Johnson K, Whitefield Y, Middleton D. A descriptive study of reportable gastrointestinal illnesses in Ontario, Canada, from 2007 to BMC Public Health [cited 2015 May 21];12: Ontario Agency for Health Protection and Promotion (Public Health Ontario). Reportable Disease Trends in Ontario. Toronto, ON: Queen s Printer for Ontario; c2014 [cited 2015 May 12]. Available from: 12.pdf 7. Ontario Ministry of Health and Long-Term Care. Campylobacteriosis reported in Ontario: 2009 to Jan 28, Public Health Agency of Canada. Campylobacter. Ottawa, ON: Government of Canada; c2013 [cited 2015 May 13]. Available from: 9. Butler AJ, Thomas MK, Pintar KDM. Expert elicitation as a mean to attribute 28 enteric pathogens to foodborne, waterborne, animal contact, and person-to-person transmission routes in Canada. Foodborne Pathog Dis [cited 2015 May 20];12(4): Government of Canada. Eat and drink safely. Ottawa, ON: Government of Canada; c2015 [cited 2015 May 29]. Available from: Government of Canada. Safe internal cooking temperatures. Ottawa, ON: Government of Canada; c2015 [cited 2015 May 22]. Available from: Monthly Infectious Diseases Surveillance Report Page 6 of 11

7 SIGNIFICANT REPORTABLE DISEASE ACTIVITY Table 1 provides a list of reportable diseases for which incidence in 2015 was found to be significantly higher (p<0.05) than expected compared to the five-year historical average. Both monthly and year-to-month (YTM) comparisons were made for each of the reportable diseases listed in Appendix 1, with the exception of influenza, measles, rubella, and congenital rubella syndrome. Influenza surveillance data are regularly reported through the Ontario Respiratory Virus Bulletin and the Laboratory-based Respiratory Pathogen Surveillance Report. Measles, rubella, and congenital rubella syndrome have been eliminated in Canada, although cases continue to occur related to travel importations. Statistical comparisons are no longer included for these diseases. Table 1. Summary of statistically significant increases in reportable disease incidence: Ontario, January 1 to April 30, 2015 Reportable disease Apr Apr 2015 Historical comparisons YTM YTM Current Current YTM YTM month month % difference avg avg in rates avg avg (current month minus avg) Gonorrhoea (All Types) 1, Ontario Cases: MOHLTC, iphis database, extracted by PHO [2015/05/13]. Ontario Population: Population Estimates [ ]: Statistics Canada, distributed by MOHLTC, received [2014/07/03]. Population Projections [ ]: MOHLTC, IntelliHEALTH Ontario, extracted by PHO [2014/04/11]. ŧ Rates listed are cases per 1,000,000 population. Percent (%) difference is calculated using unrounded rates; numbers displayed in these columns may vary from calculations using rounded rates. 1 Statistically significant difference (p<0.05) in incidence reported in year-to-month (January 1 to April 30, 2015) compared to the five-year historical average (January 1 to April 30, 2010-, using a likelihood ratio test. 2 Statistically significant difference (p<0.05) in incidence reported in current month (April 2015) compared to the five-year historical average (April 2010-, using a likelihood ratio test. % difference in rates (YTM 2015 minus YTM avg) avg annual count GONORRHEA (ALL TYPES) Compared to the five-year historical averages, there were statistically significant increases in both the monthly and YTM incidence rates of gonorrhea reported in April 2015 and cumulatively from January 1 to April 30, 2015 (13.5% and 20.9%, respectively). The monthly incidence rate of laboratory-confirmed gonorrhea reported in April 2015 decreased by 7.0% (from 31.6 to 29.4 cases per 1,000,000 population) compared to April The YTM incidence rate for cases reported between January 1 and April 30, 2015, however, increased by 1.0% (from to per 1,000,000) compared to the same time period in With the exception of January 2015, Ontario has experienced a statistically significant increase in the monthly and YTM incidence of gonorrhea, compared to five-year historical averages, since September Monthly Infectious Diseases Surveillance Report Page 7 of 11

8 2013. The cause of this ongoing provincial increase in reported gonorrhea cases is not yet well understood and is likely multifactorial. For a summary of the analyses conducted to-date, please refer to the Infectious Disease In Focus section of the February 2015 issue of this report. Also, to download the slides and/or audio recording of a recent PHO Rounds presentation on gonorrhea (May 2015), please click here. INFECTIOUS DISEASE ACTIVITY IN OTHER JURISDICTIONS This section of the report provides a snapshot of current activity related to infectious diseases across Canada and/or globally. The items included in this section are selected based on ongoing or potential implications for public health in Ontario. Current high profile infectious disease activity in other jurisdictions has been described in recent issues of this report. Please refer to the August 2014 issue for a review of the ebola outbreak in West Africa, and the October 2014 issue for a review of enterovirus D68. RECENTLY DISCONTINUED ENHANCED SURVEILLANCE DIRECTIVES VEROTOXIN-PRODUCING ESCHERICHIA COLI (VTEC) This section describes two distinct Escherichia coli O157:H7 investigations: a national investigation, and a separate provincial investigation in Ontario. National Investigation The Public Health Agency of Canada (PHAC) led an investigation along with federal and provincial partners to share epidemiological, microbiological, and food safety information related to Escherichia coli O157:H7 cases with matching pulsed-field gel electrophoresis (PFGE) pattern combination ECXAI.3198, ECBNI An Outbreak Investigation Coordinating Committee (OICC) was established April 8, PHO issued an enhanced surveillance directive (ESD) April 14, 2015 to assist with the timely collection of information for Ontario cases. Thirteen outbreak-confirmed cases were reported nationally, including one case in Ontario. Onset dates for outbreak-confirmed cases ranged from March 13 to March 31, Leafy greens were of interest in the investigation. PHAC posted a Public Health Notice on their website on April 15, Media lines were also prepared to accompany the notice. The outbreak was declared over as of April 27, 2015 and the ESD was discontinued on May 1, The OICC was deactivated May 12, Ontario Investigation PHO led an investigation along with provincial partners and PHUs to share epidemiological, microbiological, and food safety information related to E. coli O157:H7 cases with matching PFGE Monthly Infectious Diseases Surveillance Report Page 8 of 11

9 pattern combination ECXAI.0248, ECBNI An Ontario Outbreak Investigation Coordinating Committee (ON-OICC) was established April 23, 2015 and an ESD was issued April 24, 2015 to assist with the timely collection of information. Three outbreak-confirmed cases were reported in Ontario, with onset dates ranging from March 27 to April 8, The source of the outbreak was not identified. The ESD was discontinued on May 1, 2015 and the outbreak was declared over as of May 2, The ON- OICC was deactivated May 4, Monthly Infectious Diseases Surveillance Report Page 9 of 11

10 Appendix Reportable Diseases Appendix 1. Confirmed cases of reportable diseases, and probable cases of select reportable diseases, by month: Ontario, * Reportable disease 2015 Historical comparisons Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec YTM YTM Ontario Cases: MOHLTC, iphis database, extracted by PHO[2015/05/13]. Ontario Population: Population Estimates [ ]: Statistics Canada, distributed by Ontario Ministry of Health and Long-Term Care, received [2014/07/03]. Population Projections [ ]: Ontario Ministry of Health and Long-Term Care, IntelliHEALTH Ontario, extracted by PHO [2014/04/11]. Column or row-specific notes: * Appendix 1 is not an exhaustive list of all reportable diseases in Ontario. Case counts for amebiasis, Lyme disease, mumps, pertussis, and West Nile Virus illness are based on the sum of confirmed and probable cases as reported in iphis. ŧ Rates listed are cases per 1,000,000 population. Percent (%) difference is calculated using unrounded rates; numbers displayed in these columns may vary from hand calculations using rounded rates. α Please refer to the Measles Epidemiologic Summary for the most recent number of confirmed cases. Monthly Infectious Diseases Surveillance Report Page 10 of 11 Current month avg Current month avg % difference rates (current month minus 5- year avg) YTM avg YTM avg % difference rates (YTM 2015 minus YTM avg) Acute Flaccid Paralysis n/a n/a n/a n/a n/a n/a n/a AIDS Amebiasis Botulism Brucellosis Campylobacter enteritis ,702 Chlamydial Infections 3,214 2,905 3,166 3, , , , ,421 Cholera Cryptosporidiosis Cyclosporiasis Encephalitis Encephalitis/Meningitis Food Poisoning, All Causes Giardiasis ,341 Gonorrhoea (All Types) , , ,531 Group A Streptococcal Disease, Invasive Group B Streptococcal Disease, Neonatal Haemophilus Influenzae B Disease, Invasive Hepatitis A Hepatitis B (Acute) Hepatitis B (Chronic) n/a n/a n/a n/a n/a n/a n/a Hepatitis C , , ,262 HIV Influenza 4,651 1,985 1, , , ,726 Legionellosis Leprosy Listeriosis Lyme Disease Malaria Measles α # # # # # # # Meningitis Meningococcal Disease, Invasive Mumps Ophthalmia Neonatorum Paralytic Shellfish Poisoning n/a n/a n/a n/a n/a n/a n/a Paratyphoid Fever Pertussis (Whooping Cough) Q Fever Rabies Rubella # # # # # # # Rubella, Congenital Syndrome # # # # # # # Salmonellosis ,777 Shigellosis Streptococcus Pneumoniae, Invasive ,174 Syphilis, Early Congenital Syphilis, Infectious Syphilis, Other Tetanus Tuberculosis Tularemia Typhoid Fever Verotoxin Producing E. coli Including HUS West Nile Virus Illness Yellow Fever Yersiniosis avg annual count

11 # Historical comparison data are not provided for measles, rubella, and congenital rubella syndrome because these diseases have been eliminated in Canada. However, as these diseases remain endemic in other countries, imported and import-related cases continue to occur in Ontario. n/a Acute Flaccid Paralysis and Paralytic Shellfish Poisoning became reportable in Ontario in December No historical data are available for comparisons. Also, a provincial case definition for chronic hepatitis B was released in January Please note that chronic and acute hepatitis B case counts are not mutually exclusive and should not be added to obtain a total for hepatitis B cases in Ontario. Historical comparisons are not available as cases of chronic hepatitis B may have been entered using varying criteria prior to this time. Does not include cases for which the Ministry of Health and Long-Term Care was selected as the Diagnosing Health Unit or cases with a Disposition Description set to DOES NOT MEET or ENTERED IN ERROR. Differentials in year over year comparisons are reflective of changes in disease incidence and changes in the size of the population. Statistical tests comparing rates were not performed when the YTM rate in previous years was zero. Case counts for tuberculosis and AIDS are based on diagnosis date and not episode date. HIV case counts are based on encounter date. Case counts for all other diseases are based on episode date. Monthly Infectious Diseases Surveillance Report Page 11 of 11