Pertussis seasonal variation in Northern Vietnam: the evidence from a tertiary hospital.

BACKGROUND: Pertussis is a highly contagious and dangerous respiratory disease that threatens children's health in many countries, including Vietnam, despite vaccine coverage. From 2015 to 2018, Vietnam experienced an increasing number of pertussis patients. Therefore, this study aimed to investigate the trend and examine the seasonal variations of pertussis in North Vietnam. METHODS: Data were collected from medical records of all under-5-year-old inpatients admitted to the National Children's Hospital in Hanoi, Vietnam (VNCH) 2015-2018. A descriptive analysis was performed to describe the distribution of incident cases by year and season. Linear multivariable regression was conducted to investigate the association between the incidence of cases and seasonality adjusted by age and vaccination status. RESULTS: We identified 1063 laboratory-confirmed patients during 2015-2018, including 247 (23.2%) severe patients. The number of pertussis patients admitted to VNCH per 1000 hospitalizations was 3.2 in 2015, compared to 1.9, 3.1, and 2.1 in 2016, 2017, and 2018, respectively. Outbreaks occurred biennially; however, there was no significant difference in the number of severe patients over this period. Most cases occurred in the hot season (509 patients, or nearly half of the study population). With the adjustment of the vaccination rate and average age, the risk of pertussis-associated hospitalization in the mild season and the hot season was 21% (95% CI [0.12; 0.3]) and 15% (95% CI [0.05; 0.25]) higher than that in the warm season, respectively. The rate of hospitalizations was high in the mild season (28.9%) and the warm season (30.8%), nearly twice as much as that in the hot season; nevertheless, the death rate was only striking high in the mild season, about 5-6 times as much as those in the other seasons. CONCLUSION: The pertussis incidence in Northern Vietnam varied between seasons, peaking in the hot season (April-July). However, severe patients and deaths increased in the mild season (December-March). Interventions, for example, communication activities on pertussis and vaccination, are of immense importance in lowering the prevalence of pertussis. In addition, early diagnoses and early warnings performed by health professionals should be encouraged.

Trajectories of depression in adolescents and young adults in Vietnam during rapid urbanisation: evidence from a longitudinal study.

OBJECTIVES: This paper investigates the trajectories of depression symptoms in adolescents and young adults, and explores factors associated with their depression. METHOD: For each respondent, three waves of data were collected in 2006, 2009 and 2013 from adolescents and young adults aged 10 to 24 years. The modified Center for Epidemiological Studies Depression Scale was used to interview participants, while the generalised estimating equation (GEE) model was used to identify whether certain factors were associated with depression. RESULTS: The mean depression scores in 2006, 2009 and 2013 were 29.76, 30.80 and 30.51 respectively. Compared to boys, girls reported higher initial levels of depressive symptoms. The depression score was found to be highest among adolescents aged 15 to 17 years. Depression among young people was associated with age, gender, marital status, education levels, general health and living location. CONCLUSION: Using longitudinal design, this research demonstrated the different trajectories of depression scores between boys and girls over time and provided evidence for interventions improving adolescent mental health in a semi-urban area of Vietnam.