OBJECTIVES AND DESIGN: Following the popular analysis strategy used in the Global Burden of Disease Study, the age-, sex-, country-specific prevalence, and disability-adjusted life years (DALYs) of asthma in China were analyzed. Meanwhile, the comparison in trends between China and other countries in the G20 was also evaluated.
RESULTS: In 2019, asthma was the 8th leading cause of the DALYs' burden of 369 diseases in China. From 1990 to 2019, the age-standardized prevalence and DALY rates of asthma in China decreased by 14% and 51%, respectively; further, the decline rate of DALYs was much higher than the global average (-51%: -43%). It is worth noting that the overall population age-standardized DALYs rate of asthma in China was the lowest in the G20 during 2019 (102.81, 95% UI: (72.30,147.42)/100,000). Moreover, the age-standardized asthma prevalence rate peaks in both childhood (178.14, 95% UI: (90.50, 329.01)/100,000) and the elderly (541.80, 95% UI: (397.79, 679.92)/100,000). Moreover, throughout the study, subjects in the 5 to 9 years old interval were a constant focus of our attention.
CONCLUSIONS: The disease burden of asthma has varied greatly by gender and age over the past 30 years. In contrast to the increasing burden in most other G20 countries, the age-standardized prevalence rate of asthma shows a significant decreasing trend in China, however, the age-standardized DALYs rate shows a fluctuating change, and has even shown a rebound trend in recent years.
METHODS: We collected classroom dust from 24 junior high schools in three geographically distanced areas in Malaysia (Johor Bahru, Terengganu and Penang), and conducted culture-independent high-throughput microbiome and untargeted metabolomics/chemical profiling.
RESULTS: 1290 students were surveyed for asthma symptoms (wheeze). In each centre, we found significant variation in the prevalence of wheeze among schools, which could be explained by personal characteristics and air pollutants. Large-scale microbial variations were observed between the three centres; the potential protective bacteria were mainly from phyla Actinobacteria in Johor Bahru, Cyanobacteria in Terengganu and Proteobacteria in Penang. In total, 2633 metabolites and chemicals were characterised. Many metabolites were enriched in low-wheeze schools, including plant secondary metabolites flavonoids/isoflavonoids (isoliquiritigenin, formononetin, astragalin), indole and derivatives (indole, serotonin, 1H-indole-3-carboxaldehyde), and others (biotin, chavicol). A neural network analysis showed that the indole derivatives were co-occurring with the potential protective microbial taxa, including Actinomycetospora, Fischerella and Truepera, suggesting these microorganisms may pose health effects by releasing indole metabolites. A few synthetic chemicals were enriched in high-wheeze schools, including pesticides (2(3H)-benzothiazolethione), fragrances (2-aminobenzoic acid, isovaleric acid), detergents and plastics (phthalic acid), and industrial materials (4,4-sulfonyldiphenol).
CONCLUSIONS: This is the first association study between high-throughput indoor chemical profiling and asthma symptoms. The consistent results from the three centres indicate that indoor metabolites/chemicals could be a better indicator than the indoor microbiome for environmental and health assessments, providing new insights for asthma prediction, prevention and control.
METHODS: Weekly influenza surveillance data for 2006 to 2011 were obtained from Bangladesh, Cambodia, India, Indonesia, the Lao People's Democratic Republic, Malaysia, the Philippines, Singapore, Thailand and Viet Nam. Weekly rates of influenza activity were based on the percentage of all nasopharyngeal samples collected during the year that tested positive for influenza virus or viral nucleic acid on any given week. Monthly positivity rates were then calculated to define annual peaks of influenza activity in each country and across countries.
FINDINGS: Influenza activity peaked between June/July and October in seven countries, three of which showed a second peak in December to February. Countries closer to the equator had year-round circulation without discrete peaks. Viral types and subtypes varied from year to year but not across countries in a given year. The cumulative proportion of specimens that tested positive from June to November was > 60% in Bangladesh, Cambodia, India, the Lao People's Democratic Republic, the Philippines, Thailand and Viet Nam. Thus, these tropical and subtropical countries exhibited earlier influenza activity peaks than temperate climate countries north of the equator.
CONCLUSION: Most southern and south-eastern Asian countries lying north of the equator should consider vaccinating against influenza from April to June; countries near the equator without a distinct peak in influenza activity can base vaccination timing on local factors.