Impact of rapid urbanization on communicable and non-communicable diseases in China

Dr. Yi HuA/Prof. Zhijie Zhang and Prof. Qingwu Jiang

Laboratory for Spatial Analysis and ModelingDepartment of Epidemiology and Biostatistics

School of Public HealthFudan University

Nov. 28, 2013

Urbanization and Health in China, the University of Sydney

The starting points for this talk

• The urbanization is rapid in China.

• The health problems are challenging.

• What we are going to do?

Urbanization refers to the increasing amount of people that live in urban areas (Wikipedia).

1. Urbanization in China

Urbanization predominantly results in the physical growth of urban areas, be it horizontal or vertical.

The rate of urbanization increased rapidly

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1950 1960 1970 1980 1990 2000 2010

Urbanization in China increases linearly after 1985.

• In 2004, 42% of Chinese were living in urban areas;

•By 2040, more than 1 billion will be living in cities, meaning another 400 million will be urbanized in the next 30 years.

Three major city clusters in the costal zone:

• Beijing-Tianjin• Yangtze River delta-Shanghai• Pearl River delta-Guangzhou

One major inland city cluster-Chongqing

The Chinese Government is pursuing a policy of urbanization, and currently China has 28 city clusters with varying degree of size and development, most still in an embryonic stage.

• Currently (up to 2012), about 52.6% of the population live in 0.4% of the land area (urban buildup area), consume 60% of the food, and create over 88% of GDP in China (National Bureau of Statistics); • Efficient in terms of food consumption and GDP;

Economic reform in the late 1970s

Drivers of urbanization

Within-country migration policies

Increasing urban-rural income

Surplus agricultural laborers

Conversion of farmland

(Yeh et al., 2011. UNFPA&IIED)

Impacts of urbanization

Urbanization: urbanized way of pollutant discharge-high intensity per unit land and per capita, such as waste discharge and concentrated vehicles;

Changes in landscape and land uses;

Urbanization

Environmental change(physical and social)

Health

Environmental change

Air quality in China

The long-term trend of aerosol extinction coefficient (AEC) recorded in Guangzhou, China from 1950s to 2000s (Tie et al., 2009).

Before 1970s, anthropogenic aerosol pollutions were very low.

The aerosol levels started increasing in the mid 1970s, when economical development rapidly increased.

Aerosol pollution reached a maximum in the mid 1980s, and has remained high up to the present.

Other aspect…

• Prosperity has resulted in general improvements in quality of life and increased healthcare provision, but may also support unhealthy life style;

• Decreasing communicable disease burden and mortality;

• Increasing non-communicable disease burden and mortality;

• The absolute difference of health risks between urban and rural areas has increased over time.

Emerging urban health trends

(Zhu et al., 2011. ES&T)

The starting points for this talk

• The urbanization is rapid in China.

• The health problems are challenging.

• What we are going to do?

2. Communicable diseases

Zhang et al., 2012. Plos One

Zhang et al., 2012. Plos One

• Preferential policy from the central and local government

• Since the late 1990s, millions of dollars have been invested by international donors to support China’s fight against infectious diseases, including the World Bank; Britain’s Department for International Development; the Australian government; The Global Fund to Fight HIV/AIDS, TB and Malaria; and other bilateral aid programs.

Reasons for decline

(Tang et al., 2013, Inf Dis Poverty)

AIDS

Annual transmission constitute of HIV and main modes of transmission of AIDS

IDU: injecting drug use; MTCT: mother-to-child transmission (Ministry of Health of China)

The distribution of cumulative AIDS cases until Sep. 2011

Ranking: Yunnan, Guangxi, Henan, Sichuan, Xinjiang (Ministry of Health of China)

• HIV likely entered China through rural border regions and subsequently spread throughout the country via migrants.

• Once HIV spread from migrants (floating population) to local permanent residents, subsequent transmissions between permanent residents and within the general population occurred rapidly and increasingly sexually. Rates of HIV/AIDS among permanent urban residents, particularly women and elderly men, have increased significantly in recent years

1918 1957 1968 1977 1997

1998/9

2003

H1

H1H3

H2

H7H5

H5H9

Spanish flu Asian Flu

 Hong Kong flu Avian Flu

H9

2004---

H5

Appearance of human influenza virus

influenza

Mutation and potential cross-species transmission of avian influenza virus

Direct costs: a large number of human cases and hospitalizations and death of economic animal;

Indirect costs: the socio-economic impact.

• The three key parameters in influenza emergence are human and animal population density, intense contact between different species to facilitate cross-species transmission, and a prevalence of respiratory diseases

• Livestock population , raised for meat supply, also plays a role in increasing the pathogenic strains of influenza.

Effects of urbanization

(Huo et al., 2006. Virginia Review of Asian Studies)

Schistosomiasis

Map of the epidemic status of schistosomiasis japonica before the 1950s in China

Disease still endemic

Transmission interrupted Transmission controlled

Map of the epidemic status of schistosomiasis japonica in China, 2000

Annual number trend of cases infected with S. japonicum in China from 1999 to 2010

Cases including acute and chronic cases(Department of Disease Control, Ministry of Health)

Transmission interrupted Transmission controlled

Disease still endemic

Map of the epidemic status of schistosomiasis japonica in China, 2010.

China is experiencing a shift in disease profile, towards non-communicable chronic diseases, and urbanization may well play a big role, possibly through changes in life styles and environmental pollution, endocrine disrupting compounds, particulate matters etc.

In China…

• China has experienced a dramatic increase in mortality and morbidity caused by NCDs.

• In 2005, deaths from NCDs accounted for 80% of all deaths (total 10.3 million) and 70% of total disability adjusted life-years lost (total 195.7 million).

• It is likely that the prevalence of NCDs will continue to rise given the advancing population aging, and increased exposure to health risk factors due to environment and lifestyle changes associated with rapid urbanization.

3. Non-communicable diseases (NCDs)

Increasing trend of mortality of 6 major chronic diseases in China

CHD: Coronary Heart Disease

Cancer

Rural versus urban differences in mortality rate (/100,000) in the top five most common cancers in China over the last 40 years.

(Zhu et al., 2011, ES&T)

Several large-scale prevalence surveys of diabetes in China

Year of Survey/Criteria of diagnosis

Sample size

Age(Yrs)

Prevalence of DM

Prevalence of IGT

Screening methods

1980*Lanzhou meeting

300,000Whole

population0.67% -

Urinary glucose+Bread meal PBG2hΔ

1986WHO 1985

100,000 25—64 1.04% -Bread meal PBG2hΔ

1994WHO 1985

210,000 25—64 2.28% 2.12% Bread meal PBG2h

1996WHO 1985

43,000 20—74 3.21% 4.76% ---

2002WHO 1999

100,000 ≥18Urban 4.5%Rural 1.8%

- FBG

2007-08WHO 1999

46,000 ≥209.7%

Urban 11.4%Rural 8.2%

15.5% FPG, OGTT

2010ADA 2010

98,658 ≥1811.6%

Urban 14.3%Rural 10.3%

50.1% FPG, OGTT, HbA1c

* Criteria of diagnosis ： FPG≥ 130mg/dl and/or postprandial 2h ≥200mg/dl and/or OGTT> (0 min 125, 30 min 190, 60 min 180, 120 min 140 or 180 min 125 ； O-toluidine method, 100g glucose ） ;

Δ PBG2h=postprandial plasma glucose 2h ； FBG=fasting blood glucose

Total diabetes includes both previously diagnosed and previously undiagnosed diabetes. Prediabetes was defined as impaired fasting glucose or impaired glucose tolerance. (Yang et al., 2010. N Engl J Med )

Prevalence of Diabetes and Pre-diabetes and Absolute Numbersof Cases among Chinese Adults 20 Years of Age or Older (2008)

Prevalence of diabetes Prevalence of pre-diabetes

Prevalence of Diabetes and Pre-diabetes among Chinese Adults 18 Years of Age or Older (2010)

(Xu et al., 2013. JAMA)

The starting points for this talk

• The urbanization is rapid in China.

• The health problems are challenging.

• What we are going to do?

4. Research and policy needs

• Most low- and middle-income countries are now facing a dual burden of epidemics of NCDs and communicable diseases.

• These diseases share some common features, such as an overlapping high-risk population, long-term care needs, supportive interventions, and co-morbidities (e.g. diabetics among TB patients).

• Multi-sectoral cooperation and coordination will be critical to tackle these emerging public health challenges through the implementation of responsive, pro-poor policies and innovative strategies.

Reform initiatives in China:

• the establishment and expansion of health insurance schemes for rural residents, which is the New Cooperative Medical Scheme (NCMS); the unemployed or informally employed urban residents, which is the Urban Resident Basic Health Insurance (URBHI); and the Urban Employee Basic Health Insurance (UEBHI).

Limitation: the service benefit packages offered by NCMS and URBHI are still very limited and focus on paying for inpatient care.Substantial costs incurred from frequent visits for treatment ofchronic diseases have become a major factor in medical impoverishment in China.

• Untangling the causal web linking urbanization and health needs a multidisciplinary approach;

• Policies to mitigate the adverse health effects of urbanization need to meet the health-care needs of highly vulnerable populations, and must follow up these populations as they potentially transfer health-care burdens to rural areas;

• The next decade of urbanization in China will demand innovative health policies that address the needs of new urban residents while providing health services for people (especially older people and the very young) who remain in rural areas.

Policy needs

China has the capacity to deal with problems

• Learning from China’s own experience of rapid development

• Universities have a major role to play

• New ways of doing things

Acknowledgment

We would like to thank Dr. Chenglong Xiong, Dr. Tiejun Zhang, Dr. Yihan Lu, Dr. Wanghong Xu, and Dr. Zhijie Zhang for providing the disease data, China Studies Center for the invitation, and Dr. Mu Li for the arrangement of this trip.

Thanks, and welcome collaborations in our lab!