Epidemiology of Tuberculosis in Hong Kong Dr Chan Chi-kuen, Alan Senior Medical Officer TB & Chest Service, Department of Health Hong Kong Special Administrative Region

Location and population of Hong Kong Situated in south of China land area 1,098 square kilometers population of 6,782,100 at mid-2000 population density of ~6,500 /sq.Km proportion aged 65 and over: 8% in 1989 and 10.9% in 2000

Location and population of Hong Kong Highly mobile population people from 170 countries visit Hong Kong visa free passenger traffic: 115.5 million in 1998 and 129 million in 1999 increase mainly due to heavy cross-boundary traffic on land after return of Hong Kong’s sovereignty to China in 1997

General Background (1) (Year 2000) Mid-year Male Female GDP per capita : US$24,403* Annual population growth rate : 0.9% Life expectancy at birth - Male : 77.0 years - Female : 82.2 years Infant mortality rate : 2.9 (per 1 000 registered live births) % population with access to safe water : 99.9%† Literacy rate : 92.4% (percentage of population aged 15 and over who have attained primary education or above) Notes : * Figure is subject to revision later on. † Figure for year 1999 80+ 75-79 70-74 65-69 60-64 55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4 Population (in thousands)

Population pyramids 2001 (mid-year) 1971 (mid-year) Male Female Male 85+ 80-84 75-79 70-74 65-69 60-64 55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4 85+ 80-84 75-79 70-74 65-69 60-64 55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4 Population (in thousands) Population (in thousands)

General health services (1) Health infrastructure (As at end 2000) Notes : * The figure refers to Hospital Authority hospitals. † The figure covers the institutions licensed under the Hospitals, Nursing Homes and Maternity Homes Registration Ordinance (Cap. 165). ‡ The figure covers the clinics and maternity homes under the Department of Health and the clinics in the correctional institutions. § The figure covers the GOP clinics with A&E service and maternity homes of the Department of Health and the hospitals in the correctional institutions.

Latest TB indicators (2001) No of new cases (all types) and rate 6,556 (97.5/100,000) No new smear positive and rate 1,857 (27.6/100,000) % smear positive out of total new cases 28.3% % retreatment cases out of total new plus retreatment 9.7% % population with access to DOTS Near 100% DOTS cure rate (new bact. positive cases) 67.9% DOTS success rate (new bact. positive cases) 76.8% DOTS case detection rates 51%(WHO estimation)

No. of TB cases (2002)

TB rate per 100,000 (2002)

General Background (2) 5 Leading Causes of Hospitalisation (1999) 5 Leading Cause of Mortality (1999) Male & Female combined Male Female Heart disease and stroke Malignant neoplasm Malignant neoplasms Heart diseases, including hypertensive heart disease Unintentional injury Cerebrovascular disease Direct obstetric causes Pneumonia, all forms COPD and asthma Injury and poisoning Note: hospitalization figures include data from private and public hospitals Source: Department of Health, Annual Report 1999/2000

Treatment outcomes (percents) 1998 1999 2000 2001 2002 Cured 71.8% 70.4% 64.8% 67.0% - Completed 7.8% 7.3% 8.0% 8.7% Defaulted 4.6% 4.7% 6.1% 4.5% Failed 6.9% 7.9% 9.2% 8.1% Died 4.2% 5.5% 3.9% 5.4% Transferred out 2.8% Non evaluated 3.5%

HIV Prevalence (2002) No. of samples/ type of sample No. of samples tested anti-HIV + Prevalence (%) Blood donors 42,292 (blood) 1 0.002 Clients attending Social Hygiene Services 53,363 (blood) 41 0.077 Drug users attending methadone clinic (UAS) 4,037 (urine) 10 0.248 Drug users attending methadone clinic (voluntary blood testing) 318 (blood)

HIV Prevalence (2002) No. of samples/ type of sample No. of samples tested anti-HIV + Prevalence (%) Patients attending chest clinic (UAS) 866 (urine) 8 0.924 Patients attending chest clinics (voluntary blood testing) 3,186 (blood) 7 0.22 Antenatal women 41,932 (blood) 0.02%

UAS for HIV in TB & Chest Service (1990 to 2001) Period Category Sample No. Tested (No. +ve) 1.12.90 - 31.1.91 Outpatient Blood 1548 5.6.91 - 5.8.91 Inpatient 485 1.4.92 – 30.6.92 1469 (2) 1.4.92 – 30.6.93 1173 Sep 95 – Nov 95 Urine 895 Sep 96 – Dec 96 998 (4) Oct 97 – Jan 98 1003 Oct 98 – Jan 99 833 Sep 99 – Dec 99 1166 (8) Sep 00 – Dec 00 1018 (5) Oct 01 – Dec 01 1071

Information system National Reference Lab (since 1998) Data flow National Reference Lab (since 1998) PATIENT WITH TUBERCULOSIS Data for cross-matching Department of Health General out- patient clinics Hospital Authority Accident and Emergency Departments Department of Health Chest Clinic (Case notification) & (Follow up) PRIMARY LEVEL Private Practitioner Death certificates (since 1999) Please use the sample flowchart provided, or modify it in accordance to your information system, to explain the process of TB surveillance as follows: What data are collected Where are data collected: at what level and by whom Where do data go—which levels Where are data compiled for reporting Who reports and to where How is treatment evaluated, e.g. cohort analysis Hospital Authority Chest Hospitals Hospital Authority Specialist Out-patient Clinics Private Hospitals SECONDARY LEVEL Hospital Authority General

Sample of TB Notification Form (used since 1995)

Using information from death certificate The percentages of notified cases traced back by using TB lab. data and death cert. information Year Using TB lab.data Using information from death certificate 1998 13.06% - 1999 10.34% 12.68% 2000 7.92% 12.96% 2001 5.14% 7.32% 2002 4.84% 6.31% 2003 4.47% 5.67% Overall 7.55% 8.85%

Sample of TB Denotification Form (Since 1999)

No. of notifications and de-notifications by year No. of de-notifications 1998 7,673 38 1999 7,512 77 2000 7,578 87 2001 7,262 228 2002 6,602 274

CONTROL OF TUBERCULOSIS IN HONG KONG Strategies - Case finding: passive vs active - Effective chemotherapy: DOTS - Treatment of latent TB infection (preventive treatment or chemoprophylaxis) - BCG vaccination - (Health education) 23