Infectious Diseases

Overall Trends

• GI illnesses most frequently reported in Ottawa continue to be campylobacter enteritis (211 cases), salmonellosis (179 cases) and giardiasis (132 cases); these illnesses made up 75% (n=522/698) of all enteric illnesses reported in Ottawa during 2018  (Figure 1). [1]
• The incidence of some enteric illnesses was higher in 2018 than in 2014: giardiasis (132 cases in 2018 vs 106 in 2014), and cyclosporiasis (24 cases in 2018 vs 8 in 2014). 
• Incidence of all enteric, food, and water-borne infections reported in Ottawa during 2018 were similar to provincial averages.[2]

Figure 1. Number of enteric infections, Ottawa, 2018

• Although GI illnesses are reported throughout the year, a higher number of cases are reported during summer months (Figure 2)  
• Seasonal patterns in GI illnesses are often linked to increases in travel, warmer temperatures, outdoor activities, and social gatherings.  

Figure 2. Rate of all enteric infections, and the number campylobacter enteritis, salmonellosis, and giardiasis infections , Ottawa, 2018, by episode month

• Incidence of most respiratory diseases and diseases transmitted by direct contact reported to Ottawa Public Health (OPH) in 2018 have been similar over the past 5 years, with the exception of seasonal influenza, invasive group A streptococcal (iGAS) disease and tuberculosis (TB). [1]

Figure 3. Number of respiratory infections and diseases transmitted by direct contact, 2018, and the number of influenza infections, 2018-2019, Ottawa

Influenza, commonly known as the "flu", is a respiratory infection caused by the influenza virus. Influenza can easily spread from person to person. Common symptoms of influenza infections are fever, cough, chills, muscle aches, sore throat, headaches, loss of appetite, stuffy or runny nose, and fatigue. Annual influenza immunization is the most effective way to protect yourself and others against influenza.

Please refer to the Seasonal Respiratory Infections and Enteric Outbreaks Surveillance Reports webpage for up-to-date and historical seasonal influenza data and reports. The 2018-2019 influenza season covers the period from September 2018 to August 2019.

• Influenza virus circulation follows a seasonal pattern, and most infections are reported between fall and spring (Figure 4). [1]
• Influenza activity was lower than usual during the 2018-2019 respiratory disease season. [1]
• Laboratory-confirmed influenza cases, the numbers of influenza outbreaks in institutions (i.e., hospitals, long-term care homes, and retirement homes), influenza-related deaths, and influenza-related hospitalizations were lower than the past season.
• The incidence of influenza in Ottawa in 2018 was lower than the average of Ontario-less-Ottawa (58/100,000 vs. 71/100,000). [2]

Each fall, the Universal Influenza Immunization Program (UIIP) makes influenza immunization available to all residents. During the 2018-19 influenza season, close to half (46%) of residents aged 18 to 64 years reported receiving an influenza immunization while (86%) of residents 65 years of age and older received an influenza immunization, which was similar to previous influenza seasons for both age groups. [3] Please refer to the Influenza Immunization webpage for more information.

Figure 4. Number of reported laboratory-confirmed influenza cases by type and episode week, Ottawa, September 2018 (week 35) to August 2019 (week 34), and historical trends

Invasive group A steptococcal (iGAS) infections can occur in skin, soft tissue, joints, the respiratory tract, or normally sterile sites of the body. Most serious iGAS cases are sterile site infections in the blood, spinal fluid, or soft tissue.

• Chronic disease and underlying medical conditions, drug and alcohol use, and being homeless or underhoused were common risks identified among individuals with iGAS infections in Ottawa during 2018. [1] These risks are consistent with iGAS at-risk populations identified elsewhere in Canada. [4]
• In 2018, 69 iGAS cases in Ottawa residents were reported to OPH, which is higher than it was 5 years ago (56 cases in 2014).  [1]
• OPH continues to monitor iGAS infections among people who are homeless or underhoused in Ottawa, and collaborate with community partners to reduce the risk of infection transmission in shelter settings.
• 2018 rates in Ottawa were lower than in Ontario-less-Ottawa. A significant increase was seen during 2014-18 across the rest of Ontario. [2]

 Tuberculosis (TB) is an infection caused by a group of Mycobacterium bacteria species.

• In 2018, 49 cases of TB (4.8 per 100,000) were reported among Ottawa residents.  The rate of TB in Ottawa has not changed much over the last 10 years. [1] The incidence of TB in Ottawa in 2018 was the same as the average of Ontario-less-Ottawa.  [2]

• Among the cases reported in Ottawa in 2018, 43% were pulmonary.  Two-thirds of pulmonary cases were male.  The average age at diagnosis was 51 years for men and 41 years for women. 

• 85% of active TB infections diagnosed in Ottawa between 2014 and 2018 were among residents born outside Canada. Most frequently reported birth countries among these individuals include India, Somalia, Philippines, Ethiopia, Haiti, and China. [1] These countries are reported to be high TB incident regions by the World Health Organization. [5]  Among Canadian-born individuals in Ottawa, Indigenous people have higher rates of TB. [1]  People in Ottawa who are marginally housed also experience disproportionately higher rates of TB.

• The total number of respiratory outbreaks reported in Ottawa's institutions and public hospitals during the 2017-2018 season was similar to past seasons, but a higher number of outbreaks were caused by influenza B than in previous years (Figure 5). [1]
• The increase in influenza B and influenza A and B respiratory outbreaks was likely due to the increased circulation of influenza B.

Figure 5. Number of respiratory infection outbreaks in institutions and public hospitals reported to Ottawa Public Health between September 2017 and September 2018, and the mean of the previous three seasons

• The total number of gastroenteritis outbreaks reported in Ottawa's institutions and public hospitals during the 2017-2018 season was lower than the previous 3 seasons (Figure 6). [1]
• Two Clostridium difficile infection (CDI) outbreaks in public hospitals were reported to Ottawa Public Health during the 2017-2018 season.

Figure 6. Number of gastroenteritis outbreaks in Ottawa institutions and public hospitals, September 2017 to September 2018, and the mean of the three previous three seasons

• The incidence of several sexually-transmitted infections has increased significantly over the past five years, whereas the rate of transmission of bloodborne infections has been relatively steady.
• Trends in sexually transmitted and blood-borne infections (STBBIs) are associated with factors such as age, ethnicity, income, gender, and sexual orientation. [6]  Populations most affected by STBBIs in Ottawa include youth; gay, bisexual, and other men who have sex with men (MSM); people who use drugs; and people who come from a country where infection is common. [1]

Figure 7. Number of reported sexually transmitted and blood-borne infections, Ottawa, 2018

• Chlamydia is the most frequently reported of all reportable infections. Chlamydia rates are increasing in Ottawa (and in the rest of Ontario).  [1] The incidence in 2018 was 380 infections per 100,000 population (corresponding to 3,806 cases); 5 years ago, in 2013, it was 257 per 100,000.
• The rate of chlamydia in Ottawa has been higher than the average of Ontario-less-Ottawa (which had 332 cases diagnosed per 100,000 in 2018) since 2014. [2]However, the rate in Ottawa is not the highest in the province. 
• Ottawa youth 15-29 years of are at highest risk. [1] The highest rate is in females aged 20-24 years (2,720 per 100,000 population).

• Condomless sex is the most common risk factor among individuals in Ottawa diagnosed with chlamydia.

• Gonorrhea is the second most frequently reported sexually transmitted infection in Ottawa, after chlamydia. Gonorrhea rates are increasing in Ottawa (and in the rest of Ontario). Incidence had been slowly increasing since the early 1990s, but then there was a 72% increase in reported cases between 2016 and 2017 followed by a 41% increase between 2017 and 2018. [1] Gonorrhea incidence in 2018 was 90 infections per 100,000 population (corresponding to 899 cases); 5 years ago, in 2013, it was 27 per 100,000.
• The rate of gonorrhea in Ottawa is higher than that in Ontario-less-Ottawa, which was 72 cases per 100,000 in 2018). However, the rate in Ottawa is not the highest in the province. [2]
• Ottawa youth 15-29 years of age and gay, bisexual, and other men who have sex with other men are at highest risk.  The highest rate is in males aged 20-29 years (350 per 100,000 population). The proportion of cases identifying as gay, bisexual, or other men who have sex with men (gboMSM) has been increasing, from 23% in 2013 to 45% in 2018.  However, an increasing number of cases are diagnosed also among men who do not identify as MSM and among women. [1]

• Condomless sex is the most common risk factor among individuals in Ottawa diagnosed with gonorrhea.

• Infectious syphilis is the third most frequently reported sexually transmitted infection in Ottawa, after chlamydia and gonorrhea. Prior to 2002, less than one case of infectious syphilis per 100,000 population was reported each year in Ottawa. [1]  However, infectious syphilis has had a resurgence:  in 2002, 2 cases were reported per 100,000; in 2015, 11 cases per 100,000 were reported; and in 2018, 16 cases per 100,000 were reported. A total of 159 cases of infectious syphilis were reported in 2018. 
• The rate in Ottawa is now higher than in Ontario-less-Ottawa, where the 2018 rate was 13 per 100,000.. [2]  However, the rate in Ottawa is not the highest in the province. 
• Ninety-seven per cent of Ottawa cases in 2018 are male, and 87% of cases identified as gay, bisexual, and other men who have sex with men (gboMSM) (MSM). [1]  The highest rates in males are in 20-59 year-olds (49 per 100,000 population). 

• Anonymous sex is the most common risk factor among individuals in Ottawa diagnosed with infectious syphilis.
• Congenital syphilis, which can occur if a woman is infected during pregnancy, has not been reported in Ottawa since 1992. [1]

• In 2018, 31 hepatitis C infections per 100,000 population were reported in Ottawa (corresponding to 309 cases), down from a record high of 96 infections per 100,000 in 1998. The rate of hepatitis C has been consistently lower in Ottawa than the average of Ontario-less-Ottawa. [1,2]
• More than half (56%) of hepatitis C diagnoses in 2018 were among males.  The highest rates among males were in 35-39 year-olds (71/100,000 population); among females, 25-34 year-olds (48/100,000 population).
• Injection drug use is the top risk factor among people diagnosed with hepatitis C.  In 2018, 44% of individuals diagnosed with hepatitis C reported injecting drugs at some point in their lifetime. [1]

• Human immunodeficiency virus (HIV) incidence in Ottawa was 8 infections per 100,000 population in 2018. Acquired acquired immunodeficiency syndrome (AIDS) incidence was 1 case per 100,000. The incidence has been increasing slightly since 2015, when 5 HIV infections and 0.4 AIDS diagnoses per 100,000 population were reported. [1]
• The incidence rate of HIV in Ottawa was higher than the average of Ontario-less-Ottawa in 2018, and the rate of AIDS has been higher in Ottawa than the average of Ontario-less-Ottawa since 2016.  However, the rates of HIV and AIDS in Ottawa are not the highest in the province. [2]
• The highest rate of HIV in Ottawa in 2018 was in males aged 30-34 years (22 per 100,000) and the highest numbers of cases were in those from, or with a sexual partner from, a country where HIV is common (47%); and in gay, bisexual, and other men who have sex with men (MSM) (33%).  Eleven percent of cases were among people who use drugs. [1]  
• Early diagnosis and treatment of HIV (before onset of AIDS) is associated with fewer complications and better odds of survival. However, only 81% of infections reported in 2018 were older (i.e., occurred more than a year before being reported).  Individuals from a country where HIV is common where more likely to be older infections (97% of infections in this group were older). [7]

• There were no acute hepatitis B cases reported in 2018 , compared with an incidence of 0.7 per 100,000 in of Ontario-less-Ottawa. [1,2] Five or fewer cases of acute hepatitis B have been reported in Ottawa annually during the last 10 years [1]
• Chronic hepatitis B incidence in 2018 was 17 infections per 100,000 population in Ottawa.  The rate of chronic hepatitis B has been stable for the last 5 years. [1]
• Individuals at highest risk for hepatitis B are immigrants to Canada from countries where hepatitis B is common. Approximately three-quarters of people diagnosed with chronic hepatitis B during 2018 were born outside Canada. [1]

Sexual health is an important aspect of one’s overall health.  Sexual health, and the ability to have safe and satisfying sexual experiences, is influenced by a number of factors, including sexual behaviours.  Some sexual behaviours are associated with sexually transmitted infections, which are most prevalent in youth 15 to 29 years of age. 

• The most common reportable vaccine-preventable diseases in 2018 were pneumococcal disease (68 cases) and chickenpox (61 cases).  [1]
• The rates chickenpox and pneumococcal disease have not changed over the past 5 years.  The rate of pneumococcal disease is not different from Ontario-less-Ottawa,but provincial data for chickenpox are not available for comparison. [2]

Figure 10. Number of cases of vaccine preventable diseases, Ottawa, 2018

Pertussis, also known as whooping cough, is a highly contagious infection. Infants under 12 months of age are most at risk of severe disease and death.

• A total of 21 pertussis infections (confirmed and probable) were reported to OPH in 2018, including 3 in children under 5 years. (Figure 10). [1]
• The rate of pertussis in Ottawa in 2018 was lower than the average of Ontario-less-Ottawa (2.1 vs. 2.7/100,000).[10]

Mumps 

Enhanced vigilance against mumps and up-to-date immunization among post-secondary students and those 18 to 30 years of age is recommended.

• An increase in mumps cases has been noted across Ontario in recent years, particularly in 24-35 year-olds. [2,9]
• In 2018, Ottawa had a lower rate of mumps (0.4 per 100,000 population) than Ontario-less-Ottawa (0.7 per 100,000 population). The majority of cases were 24 to 35 years of age.

Measles 

Childhood Immunization

Influenza Immunization

Each fall, the Universal Influenza Immunization Program (UIIP) makes influenza immunization available to all residents. Ottawa residents can receive a seasonal influenza immunization from their health care provider, a pharmacist, or at an Ottawa Public Health clinic. While the UIIP offers immunization to all Ontarians, there are groups for which influenza immunization is prioritized, who are at high risk of complications or who those who are capable to transmitting influenza to those at high risk for complications. These include, for example, children under five years of age, older adults over 65 years of age, those with chronic conditions and health care workers. [12] There are limited immunization data on these populations. 

• Half (50%) of Ottawa residents aged 18 years and older reported receiving an influenza immunization during the 2020-21 influenza season. [3]
• Immunization rates are higher among older adults. During the 2020-21 influenza season, 43% of residents aged 18 to 64 years reported receiving an influenza immunization while 74% of residents 65 years of age and older received an influenza immunization. Influenza immunization was lower for older adults in the 2020-21 season than in previous seasons (Figure 11).  [3]
• Almost half (49%) of residents said they got their influenza immunization at a pharmacy, 20% at a doctor’s office, 10% at a public health unit clinic, 7% at a community health centre and 4% at a hospital. [3]

Figure 11. Percentage of Ottawa adults reporting influenza immunization by age group and influenza season, 2013/14 to 2020/21

• Lyme disease and West Nile virus infection are the only two reportable vector-borne diseases that can be acquired locally for which cases were reported in 2018 (Figure 12).  There has been significant Lyme and West Nile activity in Ottawa in recent years. [1]
• Malaria and yellow-fever are no longer reportable diseases in Ontario. Historical cases in Ottawa were always travel-related.  
• Four cases of travel-related brucellosis and one case of travel-related Q fever were reported in 2018.
• No cases of the other reportable vector-borne diseases were reported in Ottawa in 2018:  anthrax, hantavirus pulmonary syndrome, plague, rabies, and tularemia.  

Figure 12. Number of cases of vector-borne and other zoonotic infections, Ottawa, 2018

Figure 13. Number and rate per 100,000 population of Lyme disease cases by year, Ottawa, 2008 to 2018

• In 2018, 90 cases of Lyme disease were reported in Ottawa, compared with 6 cases reported in 2008 (Figure 13). [1] Of the 2018 cases, 27% reported exposure within Ottawa, 23% within Ottawa and outside Ottawa, while 51% reported exposure only outside of Ottawa.
• Compared with the incidence rate of Lyme in the 3 Ontario health units neighbouring Ottawa combined, the rate in Ottawa is lower (30/100,000 vs. 9/100,000). [2,13]
• Most Lyme cases are reported to Ottawa Public Health (OPH) during months without snow cover, when ticks are most active and people spend more time in outdoor settings. [1]
• The City of Ottawa is an established Lyme disease risk area. [13]  Tick surveillance work conducted by OPH estimates that 20% or more of ticks in the area are infected with the disease causing bacterium, Borrelia burgdorferi. 
• In 2017, 89% of Ottawa adults were aware of Lyme disease, 81% of those aware knew that people can get Lyme from tick, and 62% of these individuals reported performing tick checks or taking steps to protect themselves from tick bites after spending time outdoors. [3]

West Nile Virus Illness

• In 2018, 7 cases of WNV infection were reported among Ottawa residents. [1] The first case of WNV infection was reported in Ottawa in 2003; 4 cases were reported that year.
• The incidence of WNV illness in Ottawa in 2018 was similar to the average of Ontario-less-Ottawa (0.7 cases per 100,000 vs. 0.9 case per 100,000). [2]

Rabies

• The most recent case of rabies acquired in Ontario was in 1967. [15]
• The distribution of rabies post-exposure prophylaxis (RPEP) for the prevention and treatment of rabies in humans is a resource-intensive OPH program. In 2017, OPH, working alongside local health care providers, coordinated the distribution of RPEP dose to 115 individuals with suspected rabies exposure. [1]

To better inform the planning and implementation of strategies that address enteric illnesses in Ottawa, Ottawa Public Health compiled the Enteric Disease in Ottawa, 2011 report, which provides data from 2010 about 15 reportable enteric diseases. The report includes the number of cases, incidence by age, sex and time of year, five-year averages and comparison with the rest of Ontario.

Enteric Disease in Ottawa Report [PDF 6.52 MB]

Enteric Disease: Knowledge to Action Report [PDF 886 KB]

The Sexually Transmitted Infections and Sexual Health in Ottawa 2011 report provides an overview of 12 types of sexually transmitted infections (STIs) in Ottawa, the number of cases, incidence rates by age and sex, 10-year averages, comparisons to the rest of Ontario, and a neighbourhood analysis of Chlamydia. The Sexually Transmitted Infections and Sexual Health in Ottawa 2011: Knowledge to Action Report outlines OPH's role in the prevention and control of STIs and promotion healthy sexuality among Ottawa's youth and adult population. 

Sexually Transmitted Infections and Sexual Health in Ottawa report [PDF 1.2 MB] 

Sexually Transmitted Infections and Sexual Health in Ottawa 2011: Knowledge to Action Report [PDF 13.1 MB]

The Tuberculosis in Ottawa 2011 report describes the state of tuberculosis (TB) in Ottawa in 2010 compared with the past and describes disease outcomes, clinical management and risk to the population. Tuberculosis in Ottawa 2011: Knowledge to Action Report outlines OPH's role in the detection, investigation, treatment and prevention of TB. 

Tuberculosis in Ottawa 2011 report [PDF 928 KB]

Tuberculosis in Ottawa 2011: Knowledge to Action Report [PDF12.8 MB]

References

1. Ministry of Health and Long-term Care (MOHLTC), integrated Public Health Information System (iPHIS), extracted by Ottawa Public Health, May 21, 2019.
2. Public Health Ontario. Query: Ottawa Public Health Unit: Historical Comparisons. Toronto, ON: Ontario Agency for Health Protection and Promotion; May 21, 2019.
3. Ottawa Public Health. Rapid Risk Factor Surveillance System, 2021.
4. Teatero, S., McGeer, A., Tyrrell, G.J., Hoang, L., Smadi, H., Domingo, M-C., Levett, P.N., Finkelstein, M., Dewar, K., Plevneshi, A., Athey, T.B.T., Gubbay, J.B., Mulvey, M.R., Martin, I., Demczuk, W., and N. Fittipaldi. Canada-Wide Epidemic of emm74 Group A Streptococcus Invasive Disease, Open Forum Infectious Diseases, Volume 5, Issue 5, 1 May 2018. https://www.doi.org/
5. World Health Organization. Global tuberculosis 2018. Geneva: World Health Organization; 2018.
6. Canadian Public Health Association. Factors Impacting Vulnerability to HIV and Other STBBIs. 
7. Friedman, DS, O’Byrne P, Roy, M.  Comparing those diagnosed early versus late in their HIV infection: implications for public health.  International Journal of STD & AIDS 28, no. 7 (2017): 693-701.
8. Ottawa Public Health. Canadian Community Health Survey 2015/16. Ontario Share File. Statistics Canada. 
9. Public Health Ontario. Mumps. 2018. https://www.publichealthontario.ca/en/BrowseByTopic/InfectiousDiseases/Pages/IDLandingPages/Mumps.aspx

10. Government of Canada. Vaccination Coverage Goals and Vaccine Preventable Disease Reduction Targets by 2025.  https://www.canada.ca/en/public-health/services/immunization-vaccine-priorities/national-immunization-strategy/vaccination-coverage-goals-vaccine-preventable-diseases-reduction-targets-2025.html#1.0. Last modified 2018-07-23

11. Ontario Agency for Health Protection and Promotion (Public Health Ontario). Immunization coverage report for school pupils in Ontario: 2017–18 school year. Toronto, ON: Queen’s Printer for Ontario; 2019.

12. Ontario Ministry of Health and Long-Term Care. Universal Influenza Immunization Program (UIIP). http://www.health.gov.on.ca/en/pro/programs/publichealth/flu/uiip/default.aspx Last modified 2018-09-19
13. Public Health Ontario. Map of Lyme Disease Risk Areas in Ontario. 2018. http://www.publichealthontario.ca/en/eRepository/Lyme_disease_risk_areas_map.pdf
14. Public Health Ontario.  September 2012 Monthly Infectious Disease Surveillance Report.  https://www.publichealthontario.ca/-/media/documents/rdto-2012.pdf?la=en

15. Public Health Ontario. 2018 Rabies Data at a Glance. https://www.publichealthontario.ca/en/diseases-and-conditions/infectious-diseases/vector-borne-zoonotic-diseases/rabies. Last modified 2020-01-20.