Public health and medical care for the world's factory: China's Pearl River Delta Region

The prevalence of preterm and low birth weight infants among migrant women in the Pearl River Delta region, China: a population-based birth cohort study

BACKGROUND

The existing literature evaluating the association between neonatal morbidity and migrant status presents contradictory results. The purpose of this study was to compare the risk of preterm birth (PTB) and low birth weight (LBW) among newborns from local and migrant women in China's Pearl River Delta (PRD) region.

METHODS

In this observational population-based study, we included all live singleton deliveries from PRD region local women and migrant women. Data were sourced from the Guangdong Medical Birth Registry Information System between Jan 1, 2014, and Dec 31, 2020. Women were categorized into three groups by maternal migrant status: local women from PRD region, migrant women from Guangdong province or from other provinces. The outcome variables that were examined included two adverse birth outcomes: PTB and LBW. The association between the risk of PTB and LBW and maternal migrant status was assessed using logistic regression.

RESULTS

During 2014-2020, 5,219,133 single live deliveries were recorded, corresponding 13.22% to local women and the rest to migrant women coming from Guangdong (53.51%) and other provinces (33.26%). PTB prevalence was highest among local women (5.79%), followed by migrant women from Guangdong (5.29%), and the lowest among migrants from other provinces (4.95%). This association did not change after including maternal age, infant sex, delivery mode, and birth season in the models. Compared to local women, migrant women from other provinces had a lower risk of LBW (4.00% vs. 4.98%, P < 0.001). The prevalence of PTB and LBW was higher among local women than migrants. The odds of delivery PTB and LBW were higher for women who were age ≥ 35. Among the three maternal migration groups, the age-LBW association displayed a typical U-shaped pattern, with those in the youngest (16-24 years) and oldest (≥ 35) age categories exhibiting the higher odds of delivering a LBW neonate. With respect to infant sex, the prevalence of PTB was significantly higher in males than females among the three maternal migration groups. An opposite trend was found for LBW, and the prevalence of LBW was higher in females among the three maternal migration groups.

CONCLUSION

The findings of this study contribute to the understanding of the epidemiology of PTB and LBW among migrant women. Our study suggests that it is the health and robust nature of migrant mothers that predisposes them to better birth outcomes. It is important to recognize that the results of this study, while supportive of the healthy migrant effect, cannot be considered definitive without some exploration of motivation for moving and changes in lifestyle postmigration.

Dynamic evolution and spatial difference of public health service supply in economically developed provinces of China: typical evidence from Guangdong Province

OBJECTIVE

The outbreak of the COVID-19 pandemic has drawn attention from all sectors of society to the level of public health services. This study aims to investigate the level of public health service supply in the four major regions of Guangdong Province, providing a basis for optimizing health resource allocation.

METHODS

This article uses the entropy method and panel data of 21 prefecture-level cities in Guangdong Province from 2005 to 2021 to construct the evaluation index system of public health service supply and calculate its supply index. On this basis, the standard deviation ellipse method, kernel density estimation, and Markov chain are used to analyze the spatiotemporal evolution trend of the public health service supply level in Guangdong Province. The Dagum Gini coefficient and panel regression model are further used to analyze the relative differences and the key influencing factors of difference formation. Finally, the threshold effect model is used to explore the action mechanism of the key factors.

RESULTS

Overall, the level of public health service supply in Guangdong Province is on an upward trend. Among them, polarization and gradient effects are observed in the Pearl River Delta and Eastern Guangdong regions; the balance of public health service supply in Western Guangdong and Northern Mountainous areas has improved. During the observation period, the level of public health services in Guangdong Province shifted towards a higher level with a smaller probability of leapfrogging transition, and regions with a high level of supply demonstrated a positive spillover effect. The overall difference, intra-regional difference and inter-regional difference in the level of public health service supply in Guangdong Province during the observation period showed different evolutionary trends, and spatial differences still exist. These differences are more significantly positively affected by factors such as the level of regional economic development, the degree of fiscal decentralization, and the urbanization rate. Under different economic development threshold values, the degree of fiscal decentralization and urbanization rate both have a double threshold effect on the role of public health service supply level.

CONCLUSION

The overall level of public health service supply in Guangdong Province has improved, but spatial differences still exist. Key factors influencing these differences include the level of regional economic development, the degree of fiscal decentralization, and the urbanization rate, all of which exhibit threshold effects. It is suggested that, in view of the actual situation of each region, efforts should be made to build and maintain their own advantages, enhance the spatial linkage of public health service supply, and consider the threshold effects of key factors in order to optimize the allocation of health resources.

The evaluation of preventive and control measures on congenital syphilis in Guangdong Province, China: a time series modeling study

Purpose

To evaluate the effectiveness of preventive and control measures for congenital syphilis (CS) implemented since 2012 in Guangdong Province, China, and assess the epidemic trend in the near future.

Methods

The interrupted time series analysis was conducted to compare changes in slope and level of CS notification rate from 2005 to 2020 in Guangdong Province and its three regions with different economic developmental levels. The ARIMA model was established to predict the new CS case number of Guangdong Province in 2021.

Results

A total of 12,687 CS cases were reported from 2005 to 2020. The CS notification rate of the province had been increasing until 2012 (128.55 cases per 100,000 live births) and then been decreasing constantly, hitting the lowest point in 2020 (5.76 cases per 100,000 live births). The severe epidemic cluster shifted from the developed region to underdeveloped ones over time. The effectiveness of the measures was proved by the significant change in the slope of the notification rate which was found in both of the provinces (− 18.18, 95% CI − 25.63 to − 10.75) and two less-developed regions (− 10.49, 95% CI − 13.13 to − 7.86 and − 32.89, 95% CI − 41.67 to − 24.10, respectively). In the developed region where the notification rate had already been decreasing in the pre-implementation period, implementing these measures also aided in hastening the rate of descent. The CS case number in 2021 was predicted to be 48, indicating a low-level epidemic.

Conclusions

The preventive and control measures have assisted Guangdong Province to control CS effectively, of which the supportive ones ensured a successful implementation. For resource-limited countries where CS is still endemic, especially guaranteeing the support in financial subsidy, professional training, supervision and so on might trigger the effectiveness of other measures and eventually make significant and sustainable progress.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-022-01791-1.

Conservation, development and the management of infectious disease: avian influenza in China, 2004-2012

There is growing evidence that wildlife conservation measures have mixed effects on the emergence and spread of zoonotic disease. Wildlife conservation has been found to have both positive (dilution) and negative (contagion) effects. In the case of avian influenza H5N1 in China, the focus has been on negative effects. Lakes and wetlands attracting migrating waterfowl have been argued to be disease hotspots. We consider the implications of waterfowl conservation for H5N1 infections in both poultry and humans between 2004 and 2012. We model both environmental and economic risk factors. Environmental risk factors comprise the conditions that structure interaction between wild and domesticated birds. Economic risk factors comprise the cost of disease, biosecurity measures and disease risk mitigation. We find that H5N1 outbreaks in poultry populations are indeed sensitive to the existence of wild-domesticated bird mixing zones, but not in the way we would expect from the literature. We find that risk is decreasing in protected migratory bird habitat. Since the number of human cases is increasing in the number of poultry outbreaks, as expected, the implication is that the protection of wetlands important for migratory birds offers unexpected human health benefits.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'.

Economic growth, urbanization, globalization, and the risks of emerging infectious diseases in China: A review

Three interrelated world trends may be exacerbating emerging zoonotic risks: income growth, urbanization, and globalization. Income growth is associated with rising animal protein consumption in developing countries, which increases the conversion of wild lands to livestock production, and hence the probability of zoonotic emergence. Urbanization implies the greater concentration and connectedness of people, which increases the speed at which new infections are spread. Globalization-the closer integration of the world economy-has facilitated pathogen spread among countries through the growth of trade and travel. High-risk areas for the emergence and spread of infectious disease are where these three trends intersect with predisposing socioecological conditions including the presence of wild disease reservoirs, agricultural practices that increase contact between wildlife and livestock, and cultural practices that increase contact between humans, wildlife, and livestock. Such an intersection occurs in China, which has been a "cradle" of zoonoses from the Black Death to avian influenza and SARS. Disease management in China is thus critical to the mitigation of global zoonotic risks.

Quantifying the adverse effect of excessive heat on children: An elevated risk of hand, foot and mouth disease in hot days

BACKGROUND

Hand, foot and mouth disease (HFMD) is a common childhood infection and has become a major public health issue in China. Considerable research has focused on the role of meteorological factors such as temperature and relative humidity in HFMD development. However, no studies have specifically quantified the impact of another major environmental agent, excessive heat, on HFMD. The current study was designed to help address this research gap.

METHODS

Case-based HFMD surveillance data and daily meteorological data collected between 2010 and 2012 was obtained from China CDC and the National Meteorological Information Center, respectively. Distributed lag nonlinear models were applied to assess the impact of excessive heat on HFMD and its variability across social-economic status and age groups.

RESULTS

After controlling the effects of several potential confounders, the commonly hot days were found to positively affect the HFMD burdens with the relative risk (RR) peaking at around 6 days of lag. The RR of HFMD in the Pearl-River Delta Region was generally higher and persisted longer than that in the remaining developing areas. Regarding the inter-age group discrepancy, children aged 3-6 years old had the highest risk of HFMD under conditions of excessive heat whereas those greater than 6 years old had the lowest. The lag structure of the impact of the extremely hot days was quite similar to that of the commonly hot days, although the relative effect of these two kinds of conditions of excessive heat might vary across regions.

CONCLUSIONS

This study indicated significantly facilitating effects of excessive heat on HFMD especially among those aged 3-6 and from developed areas. Results from the current study were particularly practical and important for developing area-and-age-targeted control programs in the context of climate change and urbanization.

The Chinese healthcare challenge: Comment on "Shanghai rising: avoidable mortality as measured by avoidable mortality since 2000"

Investments in the extension of health insurance coverage, the strengthening of public health services, as well as primary care and better hospitals, highlights the emerging role of healthcare as part of China's new growth regime, based on an expansion of services, and redistributive policies. Such investments, apart from their central role in terms of relief for low-income people, serve to rebalance the Chinese economy away from export-led growth toward the domestic market, particularly in megacity-regions as Shanghai and the Pearl River Delta, which confront the challenge of integrating migrant workers. Based on the paper by Gusmano and colleagues, one would expect improvements in population health for permanent residents of China's cities. The challenge ahead, however, is how to address the growth of inequalities in income, wealth and the social wage.

Shanghai rising: health improvements as measured by avoidable mortality since 2000

Over the past two decades, Shanghai, the largest megacity in China, has been coping with unprecedented growth of its economy and population while overcoming previous underinvestment in the health system by the central and local governments. We study the evolution of Shanghai's healthcare system by analyzing "Avoidable Mortality" (AM) - deaths amenable to public health and healthcare interventions, as previously defined in the literature. Based on analysis of mortality data, by cause of death, from the Shanghai Municipal Center for Disease Control and Prevention, we analyze trends over the period 2000-10 and compare Shanghai's experience to other mega-city regions - New York, London and Paris. Population health status attributable to public health and healthcare interventions improved dramatically for Shanghai's population with permanent residency status. The age-adjusted rate of AM, per 1,000 population, dropped from 0.72 to 0.50. The rate of decrease in age-adjusted AM in Shanghai (30%) was comparable to New York City (30%) and Paris (25%), but lower than London (42%). Shanghai's establishment of the Municipal Center for Disease Control and Prevention and its upgrading of public health and health services are likely to have contributed to the large decrease in the number and rate of avoidable deaths, which suggests that investments in public health infrastructure and increasing access to health services in megacities - both in China and worldwide - can produce significant mortality declines. Future analysis in Shanghai should investigate inequalities in avoidable deaths and the extent to which these gains have benefitted the significant population of urban migrants who do not have permanent residency status.

Tobacco smoking among migrant factory workers in Shenzhen, China

BACKGROUND

While several studies of smoking behaviors in rural-to-urban Chinese migrants exist, none to our knowledge have focused on factory workers, estimated to represent between 10% and 20% of China's total rural-to-urban migratory population. This paper assesses factors associated with smoking behavior among rural-to-urban migrant factory workers in Shenzhen, China.

METHODS

A cross-sectional survey of migrant workers from 44 randomly selected factories in Shenzhen, China. Participants were migrant factory workers aged 16-59 years and holding nonlocal household registration. The main outcome measures were demographic, migration-related, and behavioral factors associated with smoking status.

RESULTS

Four thousand and eighty-eight completed questionnaires were obtained (response rate 95.5%). Overall smoking prevalence (including occasional, daily, and heavy daily smoking) was 19.1%. The prevalence of daily smoking (including heavy daily smoking) was higher in men (27.3%) than women (0.7%). These rates are significantly lower than national smoking rates (59.5% in men, 3.7% in women) and rates found in a similar study. A high-risk group of men who smoke heavily and consume alcohol frequently was identified. Longer working hours and less rest were associated with higher rates of smoking. Frequent Internet use and lack of insurance were associated with lifetime smoking. Gender-adjusted models showed that poorer mental health and an accumulated working time in Shenzhen of 2-3 years increased female workers' likelihood of smoking.

CONCLUSIONS

Migrant factory workers in Shenzhen had lower rates of smoking than other population groups in China. The identification of risk factors for heavy smoking may help to effectively target health promotion interventions.