Effect of the One-Child Policy on Influenza Transmission in China: A Stochastic Transmission Model

Abstract

BackgroundChina's one-child-per-couple policy, introduced in 1979, led to profound demographic changes for nearly a quarter of the world's population. Several decades later, the consequences include decreased fertility rates, population aging, decreased household sizes, changes in family structure, and imbalanced sex ratios. The epidemiology of communicable diseases may have been affected by these changes since the transmission dynamics of infectious diseases depend on demographic characteristics of the population. Of particular interest is influenza because China and Southeast Asia lie at the center of a global transmission network of influenza. Moreover, changes in household structure may affect influenza transmission. Is it possible that the pronounced demographic changes that have occurred in China have affected influenza transmission?Methods and FindingsTo address this question, we developed a continuous-time, stochastic, individual-based simulation model for influenza transmission. With this model, we simulated 30 years of influenza transmission and compared influenza transmission rates in populations with and without the one-child policy control. We found that the average annual attack rate is reduced by 6.08% (SD 2.21%) in the presence of the one-child policy compared to a population in which no demographic changes occurred. There was no discernible difference in the secondary attack rate, −0.15% (SD 1.85%), between the populations with and without a one-child policy. We also forecasted influenza transmission over a ten-year time period in a population with a two-child policy under a hypothesis that a two-child-per-couple policy will be carried out in 2015, and found a negligible difference in the average annual attack rate compared to the population with the one-child policy.ConclusionsThis study found that the average annual attack rate is slightly lowered in a population with a one-child policy, which may have resulted from a decrease in household size and the proportion of children in the population.

Epidemiology of infectious diarrhoea and the relationship with etiological and meteorological factors in Jiangsu Province, China

“…In addition to the faecal-oral route, the major pathogens in Class 2 such as rotavirus and norovirus can be transmitted among children through airborne droplets and vomit 19,20 . Since the family planning policy was cancelled in 2013, the number of Chinese children has drastically increased 21 . Among them, those aged 0–5 years spend more time indoors, which increases the possibility of human-to-human transmission.…”

Distribution of influenza virus types by age using case-based global surveillance data from twenty-nine countries, 1999-2014

“…Many factors affect the probability of being infected with influenza and of being captured by a national influenza surveillance system in each age group. The factors include epidemiological characteristics like the number of effective contacts among susceptible people, the country’s population density and mobility [ 22 , 23 ], the typical family composition and the average number of people living in a household [ 24 , 25 ], and the pattern of contacts between people of different age groups [ 26 – 28 ]. Other important factors include influenza vaccine uptake and how national surveillance systems are structured (e.g.…”

Breastfeeding practices on postnatal wards in urban and rural areas of the Deyang region, Sichuan province of China

“…In 2015, the Chinese government published a new population policy stating that “all resident couples will now be allowed to have two children” [ 15 ]. This was the most important reformation of the one-child policy since 1979 [ 16 ]. In order to meet the challenges of the next peak birth period in China brought about by the new “two child policy”, and to reduce infant mortality and improve young children’s health, it is recommended that breastfeeding, rather than infant formula, should be promoted more vigorously [ 17 , 18 ].…”