Quarterly Digest
Volume 8 - Number 3 March 1999

• Preface
  
  
• Map: B.C. Local Health Areas
  
  
• British Columbia: Local Health Areas (LHA) within Health Regions
  
  
• Vital Event Statistics - July 1, 1998 - September 30, 1998
  (Population, Livebirth, Death, Marriage, Stillbirth, Infant Deaths)
  
  
• Selected Birth Statistics - July 1, 1998 - September 30, 1998
  (Low Birthweight, Preterm, Teenage Mother, Elderly Gravida, Cesarean Section)
  
  
• External Causes of Death - July 1, 1998 - September 30, 1998
  (Accidents - [Motor Vehicle Accidents, Poisoning, Falls, Burns/Fire, Drowning, Other], Suicide, Homicide, Other External Causes)
  
  
• Neoplasm Deaths - July 1, 1998 - September 30, 1998
  (Lung, Female Breast, Colorectal, Other G.I., Female Reproductive, Prostate, Blood/Lymph, Other Malignancy, Nonmalignant and Unspecified)
  
  
• Heart Disease Deaths - July 1, 1998 - September 30, 1998
  (Rheumatic/Valvular, Hypertension, Ischemic, Conductive & Dysrhythmic, Heart Failure, Congenital, Other)
  
  
• Respiratory Disease Death Statistics - July 1, 1998 - September 30, 1998
  (Emphysema, COPD, Pneumonia, Influenza, Asthma, Lung Disease from External Agents, Pulmonary Fibrosis, Other Respiratory)
  
  
• Other Selected Death Statistics - July 1, 1998 - September 30, 1998
  (Diabetes, Alcohol-Related, AIDS, Other Infectious Disease, Cerebral and Other Vascular, Liver Disease, Amyotrophic Lateral Sclerosis and Multiple Sclerosis, Alzheimer's Disease, Parkinson's Disease)
  
  
• Summary Article:
  The Impact of Infectious Diseases on Mortality in BC, 1990-1997.
  by Z. Kashaninia

• Glossary
  
  
• Contributors' Note
  
  
• Readers' Note
  
  

Preface

Due to the fact that Vital Statistics Agency files are continually being updated, totals compiled by addition of the annual quarters will not correspond exactly to year-to-date and year-end figures. For the same reason, depending on the date the data are extracted, there will be differences in numbers presented in this year's Quarterly Digests and those eventually reported in the Vital Statistics 1998 Annual Report. Therefore, the numbers provided in this report should be considered provisional. Finally, the usual cautions regarding random fluctuations in values, particularly those involving small numbers, must be noted.

This "Quarterly's" feature article examines the impact of infectious diseases, or perhaps more accurately, diseases caused by infectious agents, on mortality in British Columbia from 1990 to 1997. Requests to this Agency for mortality statistics relating to specific issues (AIDS, hepatitis, meningitis, influenza, necrotizing fasciitis etc.) have increased. Also, medical coding staff have been aware of changes in the type of these diseases that are newly appearing on death records. This article is unique because it combines various diseases from several chapters within the International Classification of Diseases in a grouping never done before; it examines impact on mortality both directly and indirectly; and uses multiple code analysis. Also, the detail by which certain diseases/organisms are identified in this article is only possible through manual examination of original documents. This report is intended as an overview that will be followed by focus on specific infectious diseases such as hepatitis or tuberculosis.

Requests for changes, suggestions for article topics or contributions continue to be welcome. Your support and input into this publication is greatly appreciated.

R.J. Danderfer	Soo-Hong Uh
Director	Manager
British Columbia	Information and Resource
Vital Statistics Agency	Management Branch
	Vital Statistics Agency

[Return to Table of Contents]

British Columbia
Local Health Areas

British Columbia:
Local Health Areas (LHA)
within Health Regions

The Impact of Infectious Diseases
on Mortality in BC, 1990-1997

Introduction

In the past, infectious disease mortality reporting has only been confined to the "Infectious and Parasitic Disease" chapter of the International Classification of Diseases (ICD-9). This report is the first of its kind to extend beyond this scope by incorporating additional infectious/endemic diseases beyond the "organism specific" chapter as well as the contribution of the newly defined grouping as secondary factors to mortality by use of multiple code analysis. Since no definition of "infectious disease" within established ICD groupings exists, there may be arguable omissions or inclusions. The approach taken here is intended to provide a more comprehensive assessment of the actual impact of infectious disease on mortality in BC.

This report will provide an overview of all infectious disease mortality in British Columbia. The two tables that are provided at the beginning of the report contain all infectious disease deaths from 1990-1997. Table 1 reports all the deaths that were caused directly by infectious disease (Direct) while Table 2 provides all the conditions among cases where infectious disease was present at the time of death but the individual directly died of something other than an infectious disease (Indirect). In both tables, all the death records of broader categories were pulled from archives and studied individually to distinguish the recently discovered diseases such as necrotizing faciitis, clostridium difficile and other diseases of interest. Throughout the report, information boxes will be provided on a number of these emerging conditions in addition to the overview of age, gender, regional differences, Age Standardized Mortality Rates (ASMRs), Standardized Mortality Ratios (SMRs) and others.

The infectious diseases included in this project are summarized as follows:

Methodology

Age Standardized Mortality Rates (ASMRs) are a summary of age adjusted death rates by gender that are standardized to a specific population to compare different time periods or geographical locations. The Vital Statistics data that are used in this report are standardized to 1971 Canada Census population.

Standardized Mortality Ratios (SMRs) are the ratio of the actual number of deaths in a Local Health Area (LHA) to the expected number of deaths in that area that are based on provincial age-specific mortality rates (SMRs are used for comparing each LHAs observed infectious disease mortality relative to the Province as a whole).

• In total, 13,398 individuals died as a direct result of an infectious disease between 1990 and 1997.

• The highest number of infectious disease deaths occurred in 1993 (1,809 deaths) while the lowest happened in 1991 (1,444 deaths).

• The highest number of deaths were caused by pneumonias, other and unspecified with the ICD codes of 483, 485 and 486 (8,540) which accounted for 63.7 percent of all infectious disease deaths.

• A number of infectious diseases showed remarkable changes from 1990 to 1997. AIDS/HIV infection deaths were down from 189 in 1990 and 294 in 1995 to 112 in 1997. Unspecified septicaemias (ICD code 0389) on the other hand increased from 51 in 1990 to 105 in 1994 and 109 in 1997. Other specified viral hepatitis (ICD codes 0704 and 0705) which included hepatitis C showed a significant increase from virtually no deaths in 1990 to 11 in 1995 and 33 in 1997. Unspecified diarrhea (ICD code 558) deaths also increased from 14 deaths in 1990 to 32 in 1996 and 27 in 1997.

• Between 1990 and 1997, a total of 23,496 individuals died of non infectious disease causes but had at least one infectious disease at the time of their death.

• The highest number of indirect infectious disease deaths occurred in 1997 with 3, 227 deaths while the lowest were in 1992 with 2,543 deaths.

• As with the direct infectious disease deaths, the highest number of indirect infectious disease deaths (18,935) were caused by pneumonias, other and unspecified (ICD codes 483, 485, 486) which accounted for over 80 percent of all indirect infectious disease deaths. It should be noted that these individuals may have had other infectious diseases in addition to having some type of pneumonia at the time of their deaths.

• Table 2 reveals interesting information about the significance of some of the emerging indirect infectious disease deaths. As contributing factors to mortality, diseases such as clostridium difficile (ICD code 0084) showed a significant increase from none in 1990 to 18 in 1997. Unspecified septicaemia (ICD code 0389) showed a steady increase from 398 in 1990 to 499 in 1994 and 626 in 1997. Other specified viral hepatitis (ICD code 0705) which included hepatitis C increased from only 6 deaths between 1990 and 1994 to 14 in 1995 and 42 in 1997. The indirect deaths with unspecified diarrhea (ICD code 558) also increased from 34 in 1990 to 50 in 1994 and 74 in 1997.

• On the other hand, deaths with diseases such as pneumocystis carinii (ICD code 1363) showed a significant decrease in 1997 with only 15 deaths which was dramatically down from 34 in 1990 and 43 in 1995. Indirect deaths with candida (ICD codes 1120-1129) decreased over the years from 14 and 15 in 1990 and 1994 to only 7 in 1997. Viral pneumonia, unspecified (ICD code 4809) was also down from 10 in 1990 to only 2 in 1997.

In 1997 infectious diseases were the fourth leading cause of death in British Columbia. With 1,723 deaths, infectious disease was fourth after cancer (7,386), heart disease (6,910) and cerebrovascular disease (2,226). Over all, 863 males and 860 females died as a direct result of infectious diseases in 1997.

• From 1990 to 1997, more males (7,330) than females (6,068) died as a direct result of an infectious disease.

• The highest number of male deaths occurred in 1994 with 1,011 deaths while the highest number of female deaths occurred in 1997 with 860 deaths. Since 1994, male deaths decreased steadily every year while female deaths increased.

Creutzfeldt-Jakob Disease Creutzfeldt-Jakob Disease (named after 2 German neurologists who separately described their patients with similar symptoms in the 1920’s) is a rare neurological disorder caused by small proteins called prions. Prions seem to damage brain cells by making them swell and burst. This is why this disease is sometimes referred to as "spongiform" disease since it causes the brain to develop holes like a sponge. The disease seems to attack the elderly population more than any other age groups and death usually occurs 3-12 months from onset. In 1995, a new kind of Creutzfeldt-Jakob Disease was discovered in cattle in some areas of Britain which was referred to as "mad cow disease". The disease produces the same symptoms in cattle as in humans. (Texas Department of health, http://www.tdh.state.tx.us/ideas/factsht/cjd.htm) From 1990 to 1997, a total of 25 individuals died as a direct result of Creutzfeldt-Jakob disease. Out of the 25 deaths, 20 were over 60 years of age (8 males and 12 females). Six individuals died of some other causes but also had Creutzfeldt-Jakob disease. These six cases were reported in 1993, 1994, 1995 and 1997.

• From 1990 to 1997, 23,496 individuals (12,686 males, 10,810 females) died indirectly of an infectious disease. This means that although these individuals died of other causes, they all had at least one infectious disease at the time of their deaths.

• The highest number of indirect infectious disease deaths occurred in 1996 for males (with 1,713 deaths) and 1997 for females (with 1,525 deaths).

Clostridium Difficile (C-difficile) Clostridium Difficile (C-difficile) is a bacteria that produces toxins which damage the intestinal cells. The organism forms spores that can survive for weeks or months outside of the human body. Some of the risk factors associated with C-difficile are: Antibiotic use, gastrointestinal procedures such as bowel surgery, patients greater than 60 years of age, inflammatory bowel disease, cancer chemotherapy and kidney disorders. (Maryland Department of Health and Mental Hygiene, Epidemiology and Disease program, October, 1989). From 1990 to 1997, a total of 25 individuals (16 females and 9 males) died as a direct result of C-difficile infections in B.C. with the highest number of cases being reported in 1997 (a total of 8, 4 males and 4 females). Except for four deaths, all those who died of the disease were over 60 years of age. During the same period, 36 individuals who died of other causes had the C-difficile infection at the time of their death. Eighteen of these cases were reported in 1997.

• Pneumonias caused the highest number of direct infectious disease deaths with a total of 8,540 over the years 1990-1997. The ICD codes for the pneumonia deaths in this group were: 483 (pneumonia due to other specified organism), 485 (bronchopneumonia, organism unspecified), and 486 (pneumonia, organism unspecified).

• AIDS/HIV infections were the second highest with 1,910 deaths and unspecified septicaemia was third with 743 deaths.

• Pneumonias were also a contributing factor to 18,935 deaths from 1990-1997.

• Of all indirect infectious disease deaths, unspecified septicaemia (with 3,997 deaths) and unspecified diarrhea (with 385 deaths) were second and third highest contributors to death.

Table 7
Infectious Disease-Related (Direct and Indirect) Age Specific Death Rates
British Columbia, 1990 - 1997

	Male	Female
<1	5.23	4.38
1-4	0.54	0.34
5-9	0.19	0.22
10-14	0.24	0.18
15-19	0.30	0.31
20-24	0.52	0.40
25-29	1.61	0.38
29-34	3.73	0.66
35-39	4.26	0.85
40-44	5.24	1.22
45-49	5.72	1.92
50-54	6.88	3.24
55-59	9.50	5.57
60-64	14.66	8.65
65-69	27.11	16.19
70-74	49.38	26.61
75-79	97.30	55.62
80-84	184.86	108.23
85+	438.99	306.82

Note: Rate per 10,000 gender specific population.

• In almost all age groups, the age specific death rates for infectious disease-related deaths were higher for males than for females.

• As mentioned before, the majority of those who die with/or of an infectious disease are the very young, elderly, and those with compromised immune systems. The age specific death rates are significant for those less than one year of age and are nearly zero until age 25 for males and 40 for females. The high rates for males age 25 to 64 can mostly be attributed to AIDS/HIV. The rates increase rapidly for both males and females over 65 years of age and peak at their highest for those 85 and over.

Acquired Immune Deficiency Syndrome (AIDS) First reported in the early 1980s, AIDS has now become a major concern worldwide. AIDS is caused by the Human Immune Deficiency Virus (HIV) which attacks and destroys the cells of the immune system by which it will eventually destroy the body’s ability to fight infections and cancers. (Johns Hopkins Health Information, Intelihealth, AIDS Fact Sheets). Between 1990 and 1997, 1,910 individuals died of AIDS/HIV infections (1,809 males and 101 females) in British Columbia. Over 62 percent of those who died were between the ages of 30 and 44. The highest number of deaths occurred in 1994 with 330 deaths (307 males, 23 females). Since 1994, there was a steady decline in AIDS/HIV deaths with 1997 reporting the lowest number of deaths at 112. This is mainly due to new medical intervention as well as prevention.

Chart 4
Infectious Disease-Related (Direct and Indirect) Age Standardized Mortality Rates
British Columbia, 1990 to 1997

Table 8
Infectious Disease-Related (Direct and Indirect) Age Standardized Mortality Rates
British Columbia, 1990 to 1997

	1990	1991	1992	1993	1994	1995	1996	1997
Male	9.77	9.58	9.23	10.14	9.66	9.58	9.22	8.37
Female	7.13	6.63	6.65	7.39	6.86	6.64	6.92	6.74
Total	8.45	8.10	7.94	8.77	8.26	8.11	8.07	7.55

Note: Rate per 10,000 standard population (using 1971 Canada Census as standard).

• From 1990 to 1992, the Age Standardized Mortality Rates (ASMRs) decreased continuously for males which can be attributed directly to a decline in AIDS/HIV mortality in recent years. 1993 presented the highest rates of ASMRs for males and females at 10.14 and 7.39 respectively. From 1994 until 1997, the rates continuously declined for males and were at their lowest in 1997 at 8.37. For females, the rates declined from 1993 and was only up slightly in 1996. The lowest ASMR rates for females were in 1991 at 6.63.

Tuberculosis Tuberculosis (TB) is caused by a germ called Mycobacterium tuberculosis that primarily affects the lungs. TB is contagious and is most commonly spread by inhaling the germs from coughs of someone who has contracted the disease. Being exposed; however, does not mean that the person will definitely contract the disease. Only 10 percent or less of the people who are exposed to TB will fully contract the disease. These individuals are generally those in an immune compromised condition. (National Jewish Medical and Research Centre, http://www.njc.org). From 1990 to 1997, 145 individuals (70 males and 75 females) died directly from TB. Seventy two percent of all the deaths from TB were in the age groups of 65 and over. During the same years, 297 (198 males and 99 females) died of some other causes but also had TB. Seventy nine percent of these individuals were also in the age groups of 65 and over.

Table 9
SMRs for Infectious Related Deaths (Direct & Indirect)
British Columbia, 1990 - 1997

	Local Health Area	Observed	Expected	SMR	Lower 95% C.I.	Upper 95% C.I.
01	Fernie	92	103.31	0.89	0.72	1.09
02	Cranbrook	181	192.62	0.94	0.81	1.09
03	Kimberley	82	106.88	0.77	0.61	0.95
04	Windermere	32	60.75	0.53	0.36	0.74
05	Creston	111	191.83	0.58	0.48	0.70
06	Kootenay Lake	33	44.60	0.74	0.51	1.04
07	Nelson	250	251.41	0.99	0.87	1.13
09	Castlegar	98	130.96	0.75	0.61	0.91
10	Arrow Lakes	82	67.34	1.22	0.97	1.51
11	Trail	272	270.20	1.01	0.89	1.13
12	Grand Forks	162	113.12	1.43	1.22	1.67
13	Kettle Valley	31	33.04	0.94	0.64	1.33
14	Southern Okanagan	311	302.29	1.03	0.92	1.15
15	Penticton	555	645.99	0.86	0.79	0.93
16	Keremeos	49	66.27	0.74	0.55	0.98
17	Princeton	75	52.53	1.43	1.12	1.79
18	Golden	34	43.16	0.79	0.55	1.10
19	Revelstoke	48	67.07	0.72	0.53	0.95
20	Salmon Arm	65	383.69	0.69	0.61	0.78
21	Armstrong-Spallumcheen	97	106.05	0.91	0.74	1.12
22	Vernon	674	649.40	1.04	0.96	1.12
23	Central Okanagan	1,386	1660.75	0.83	0.79	0.88
24	Kamloops	699	725.88	0.96	0.89	1.04
26	North Thompson	21	30.73	0.68	0.42	1.04
27	Cariboo-Chilcotin	281	258.98	1.09	0.96	1.22
28	Quesnel	169	162.01	1.04	0.89	1.21
29	Lillooet	45	40.28	1.12	0.81	1.49
30	South Cariboo	75	68.32	1.10	0.86	1.38
31	Merritt	111	80.92	1.37	1.13	1.65
32	Hope	79	84.50	0.93	0.74	1.17
33	Chilliwack	745	715.41	1.04	0.97	1.12
34	Abbotsford	1,026	1120.74	0.92	0.86