MLHU - Health Status Resource

Infectious diseases

Infectious diseases, also known as communicable diseases, are those that can spread from an infected person, animal, or object to another person, potentially making others ill. Young children are at risk for acquiring and spreading infectious diseases since they play closely together, often put objects in their mouth, and have immune systems that are still developing. Older children and youth are less at risk because their immune system is better developed and they have better hygiene.¹

Ontario public health units work to ensure that children and youth have up-to-date immunizations to prevent vaccine preventable diseases such as measles, mumps, polio, rubella, and tetanus. In Middlesex-London, the incidence of most of these diseases was rare or low from 2005–2018. When comparing across all age groups, Middlesex-London youth had high rates of chlamydia infections, while children under the age of ten had the highest rates of cryptosporidiosis, giardiasis, salmonellosis, and verotoxin-producing Escherichia coli (E. coli) (VTEC) infections from 2014–2018. While health promotion and protection efforts are well established in Middlesex-London, improvements are still needed to decrease the burden of infectious diseases among children and youth in our community.

The Infectious Disease topic contains data for the overall Middlesex-London population on rates of sexually transmitted and blood-borne infections, respiratory infections, enteric infections, infections prevented by routine immunization, and other infectious diseases of public health significance.

Sexually-transmitted and blood-borne infections	Infections prevented by routine immunization
Respiratory infections	Other infectious diseases of public health significance
Enteric infections

Sexually transmitted and blood-borne infections

The Sexually Transmitted and Blood-borne Infections section contains data for the overall Middlesex-London population from 2005 to 2018.

Youth age 15–19 had the second highest rate of chlamydia infections in Middlesex-London from 2014–2018 (Figure 9.1.3). The rate was nearly three times higher in females compared to males in this age group.

The 15–19 age group had the third highest rate of gonorrhea infections in Middlesex-London from 2014–2018 (Figure 9.1.6). The rate was higher among females compared to males in this age group, but the difference was not statistically significant.

From 2014–2018, there were no reported cases of hepatitis C infections among those 14 and under in Middlesex-London (Figure 9.1.9). Among the Middlesex-London population age 15 years and older, the rate of infections was lowest among those age 15–19.

Across all age groups, the rate of HIV/AIDS infections in Middlesex-London was lowest among children and youth (0–19) from 2014–2018 (Figure 9.1.12).

From 2014–2018, there were no reported cases of syphilis infections among those age 14 and under in Middlesex-London (Figure 9.1.17). Among those age 15 years and older in Middlesex-London, youth age 15–19 had the lowest rate of syphilis infections (8.3 per 100,000) and all reported cases were among males.

Interpretation

Sexually transmitted and blood-borne infections (STBBIs) are those that can be spread from an infected person to others through sexual contact, or through blood, such as when injection equipment is used by more than one person. Some STBBIs can also be passed from an infected mother to her fetus during pregnancy, or during delivery when the infant passes through the infected birth canal.²

Respiratory infections

The Respiratory Infections section contains data for the overall Middlesex-London population from 2005 to 2018.

Children under the age of one had the second highest rate of influenza infections in Middlesex-London from 2014–2018 (Figure 9.2.2). Among children and youth in Middlesex-London, influenza rates decreased significantly with age; those age 10–19 had the second lowest rate of infections across all age groups.

Rates of active tuberculosis infections among Middlesex-London children and youth (age 0–19) were significantly lower compared to the 20–29 age group from 2014 to 2018 (Figure 9.2.5).

Interpretation

Children under 60 months of age are at high risk of developing influenza-related complications or hospitalization. Getting the annual influenza vaccination is the most effective way to help prevent influenza and its complications.³

Enteric infections

The Enteric Infections section contains data for the overall Middlesex-London population from 2005–2018.

The rate of cryptosporidiosis infections in Middlesex-London generally decreased with increasing age in from 2014–2018 (Figure 9.3.7). Across all groups, the rate was highest among children age 0–9, followed by youth age 10–19.

The rate of giardiasis infections was highest among children under the age of 10 in Middlesex-London from 2014–2018 (Figure 9.3.11); however, the differences in rates between age groups were not statistically significant.

Across all age groups, the rate of salmonellosis infections was highest in the 0–9 age group (Figure 9.3.15). The rate among those under the age of 10 years was significantly higher than the rates among all age groups 30 years of age and older.

The rate of verotoxin-producing Escherichia coli (E. coli) (VTEC) infections was highest among children under the age of 10 in Middlesex-London from 2014–2018 (Figure 9.3.19). The second highest rate across all age groups was among children and youth age 10–19.

Among Middlesex-London residents, the rate of yersiniosis infections was highest among those 10–19 years of age (Figure 9.3.21). However, the differences between age groups were not significant.

Among children and youth age 0–9 and 10–19 in Middlex-London, rates of amebiasis (Figure 9.3.3), campylobacteriosis (Figure 9.3.5), cyclosporiasis (Figure 9.3.9), and hepatitis A (Figure 9.3.13) infections were lower compared to older age groups from 2014–2018.

The rate of shigellosis infections among children and youth age 0–9 and 10–19 were lower compared to those age 20–29, but the differences were not statistically significant (Figure 9.3.17).

Interpretation

Enteric infections are caused by microorganisms such as viruses (e.g., Hepatitis A), bacteria (e.g., Campylobacter spp., Escherichia coli, Salmonella spp.), and protozoans (Giardia spp., Cyclospora spp.) that cause intestinal illness. Infants and young children (age 0–4) are at greater risk of infection and serious illness from enteric pathogens compared to other age groups, except for the elderly.⁴ For Canadian infants under the age of one, Salmonella spp. infections are most frequently reported. Children age one to four have the highest reported rates of Campylobacter spp., Giardia spp., Salmonella spp., and verotoxin-producing Escherichia coli (VTEC) infections. Hepatitis A infections are most frequently reported for Canadian children age five to 15.⁴

Good hand hygiene can help to limit children’s and youth’s exposure to enteric pathogens and thus prevent illness.

Infections prevented by routine immunization

The Infections Prevented by Routine Immunization section contains data for the overall Middlesex-London population from 2005–2018.

Among Middlesex-London residents, the rate of pertussis infections was highest among infants less than one year of age, followed by children 1–9 years old (Figure 9.4.2). Pertussis rates generally decreased with increasing age.

Children under the age of one had the second highest rate of invasive Streptococcus pneumoniae infections in Middlesex-London from 2014–2018 (Figure 9.4.4)

Interpretation

Infectious diseases can spread at school among children and youth who are not vaccinated.⁵ The Immunization of School Pupils Act (ISPA) requires that students attending primary or secondary schools in Ontario be immunized against certain diseases. The Immunization topic contains data on childhood immunization coverage, adolescent immunization coverage, and school-based immunization coverage.

Other infectious diseases of public health significance

The Vector-borne Infections and Other Infectious Diseases of Public Health Significance sections contain additional data for the overall Middlesex-London population from 2005–2018.

The rate of Lyme disease infections among children and youth age 0–9 and 10–19 were lower compared to those age 30 and older, but the difference was not statistically significant (Figure 9.5.2).

The rate of encephalitis/meningitis infections among children age 0–9 was significantly higher than for all other age groups in Middlesex-London from 2014–2018 (Figure 9.7.2).

Across all age groups, children and youth in Middlesex-London had the lowest rate of invasive Group A Streptococcus disease in 2014–2018 (Figure 9.7.4); the rate was 5.2 per 100,000 population among children age 0–9, and 0.8 per 100,000 among those age 10–19.

Interpretation

Rates of encephalitis/meningitis were highest among children under 10 years of age. It is possible that this age group is more susceptible to the pathogens that cause encephalitis/meningitis, and truly experience a greater burden of illness. However, the higher rate may be partially due to increased testing, and therefore more infections being detected. Health care providers may be more likely to test children who exhibit symptoms of encephalitis/meningitis than older individuals who have similar signs but may be better able to communicate, allowing them to help the health care provider narrow the possible diagnoses.

In Ontario, cases of invasive Group A Streptococcal (iGAS) disease are most commonly reported in adults 65 years of age and older, followed by children under the age of one.⁶ Among children, a recent chickenpox infection increases the risk for iGAS disease.⁷, ⁸