1.Epidemiological update on the dengue situation in the Western Pacific Region, 2012
Arima Yuzo ; Chiew May ; Matsui Tamano
Western Pacific Surveillance and Response 2015;6(2):82-89
Dengue has caused a substantial public health burden in the Western Pacific Region. To assess this burden and regional trends, data were collated and summarized from indicator-based surveillance systems on dengue cases and deaths from countries and areas in the Western Pacific Region. In 2012, dengue notifications continued to increase with 356 838 dengue cases reported in the Region (relative to 244 855 cases reported in 2011) of which 1248 died. In the Asia subregion, the notification rate was highest in Cambodia, the Philippines and the Lao People's Democratic Republic (316.2, 198.9 and 162.4 per 100 000 population, respectively), and in the Pacific island countries and areas, the notification rate was highest in Niue, the Marshall Islands and the Federated States of Micronesia (8556.0, 337.0 and 265.1 per 100 000 population, respectively). All four serotypes were circulating in the Region in 2012 with considerable variabilitiy in distribution. Regional surveillance provides important information to enhance situational awareness, conduct risk assessments and improve preparedness activities.
2.Sex matters – a preliminary analysis of Middle East respiratory syndrome in the Republic of Korea, 2015
Jansen Andreas ; Chiew May ; Konings Frank ; Lee Chin-Kei ; Ailan Li
Western Pacific Surveillance and Response 2015;6(3):68-71
Convincing evidence suggests that females and males are different in regard to susceptibility to both infectious and non-infectious diseases. Sex and gender influences the severity and outcome of several infectious diseases, including leptospirosis, tuberculosis, listeriosis, Q fever, avian influenza and SARS.
3.The changing epidemiology of measles in an era of elimination: lessons from health-care-setting transmissions of measles during an outbreak in New South Wales, Australia, 2012
Alexis Pillsbury ; May Chiew ; Shopna Bag ; Kirsty Hope ; Sophie Norton ; Stephen Conaty ; Vicky Sheppeard ; Peter McIntyre
Western Pacific Surveillance and Response 2016;7(4):12-20
Introduction: In countries where measles is rare, health-care-setting transmissions remain problematic. Australia experienced its largest measles outbreak in 15 years in 2012 with 199 cases reported nationally; 170 cases occurred in the state of New South Wales (NSW) with symptom onset between 7 April and 29 November 2012.
Methods: A descriptive study was conducted using measles case data obtained from metropolitan Sydney local health districts in NSW in 2012. Characteristics of measles source and secondary cases were described. Details of health-care presentations resulting and not resulting in measles transmission were also analysed.
Results: There were 168 confirmed and two probable cases resulting in 405 documented health-care presentations. Thirty-four secondary cases acquired in health-care settings were identified, including 29 cases resulting from 14 source cases and 5 cases whose source could not be identified. Health-care-acquired cases accounted for 20% of all cases in this outbreak. Source cases were more likely to be of Pacific Islander descent (p = 0.009) and to have had more presentations before diagnosis (p = 0.012) compared to other cases. The percentage of presentations to emergency departments was higher for presentations that resulted in transmission compared to those that did not (71.4% and 37.6%, respectively, p = 0.028). There were no significant differences between transmission and non-transmission presentations with respect to presence of rash and infection control measures (p = 0.762 and p = 0.221, respectively), although the power to detect these differences was limited. Rash was reported at 66% of the presentations.
Conclusion: Development of and adherence to protocols for the management of patients presenting to hospitals with fever and rash will minimize secondary transmission of measles.
4.Regional event-based surveillance in WHO’s Western Pacific Region
Christopher Lowbrdige ; May Chiew ; Katherine Russel ; Takuya Yamagishi ; Babatunde Olowokure ; Ailan Li
Western Pacific Surveillance and Response 2020;11(2):11-19
Abstract
In the Western Pacific Region, event-based surveillance has been conducted for over a decade for rapid detection and assessment of acute public health events. This report describes the establishment and evolution of the Western Pacific regional event-based surveillance system and presents an analysis of public health events in the Region. Between July 2008 and June 2017 there was a total of 2396 events reported in the Western Pacific Region (average of 266 events per year). Events related to infectious diseases in humans account for the largest proportion of events recorded (49%). Maintaining this well-established system is critical in supporting rapid detection, assessment and response to acute public health events, to maintain regional health security.
5.Estimating the national burden of hospitalizations for influenza-associated severe acute respiratory infection in the Lao People’s Democratic Republic, 2016
Bouaphanh Khamphaphongphane ; May Chiew ; Joshua Mott ; Sombandith Khamphanoulath ; Viengphone Khanthamaly ; Keooudomphone Vilivong ; Thongchanh Sisouk ; Leila Bell ; Erica Dueger ; Sheena Sullivan ; Angela Daniella Iuliano ; Reiko Tsuyuoka ; Onechanh Keosavanh
Western Pacific Surveillance and Response 2021;12(2):19-27
Objective: Estimates of the burden of influenza are needed to inform prevention and control activities for seasonal influenza, including to support the development of appropriate vaccination policies. We used sentinel surveillance data on severe acute respiratory infection (SARI) to estimate the burden of influenza-associated hospitalizations in the Lao People’s Democratic Republic.
Methods: Using methods developed by the World Health Organization, we combined data from hospital logbook reviews with epidemiological and virological data from influenza surveillance from 1 January to 31 December 2016 in defined catchment areas for two sentinel sites (Champasack and Luang Prabang provincial hospitals) to derive population-based estimates of influenza-associated SARI hospitalization rates. Hospitalization rates by age group were then applied to national age-specific population estimates using 2015 census data.
Results: We estimated the overall influenza-associated SARI hospitalization rate to be 48/100 000 population (95% confidence interval [CI]: 44–51) or 3097 admissions (95% CI: 2881–3313). SARI hospitalization rates were estimated to be as low as 40/100 000 population (95% CI: 37–43) and as high as 92/100 000 population (95% CI: 87–98) after accounting for SARI patient underascertainment in hospital logbooks. Influenza-associated SARI hospitalization rates were highest in children aged <5 years (219; 95% CI: 198–241) and persons aged >=65 years (106; 95% CI: 91–121).
Discussion: Our findings have identified age groups at higher risk for influenza-associated SARI hospitalization, which will support policy decisions for influenza prevention and control strategies, including for vaccination. Further work is needed to estimate the burdens of outpatient influenza and influenza in specific high-risk subpopulations.
6.An epidemiological overview of human infections with HxNy avian influenza in the Western Pacific Region, 2003–2022
Jozica Skufca ; Leila Bell ; JC Pal Molino ; Dina Saulo ; Chin-kei Lee ; Satoko Otsu ; Kim Carmela Co ; May Chiew ; Phetdavanh Leuangvilay ; Sarika Patel ; Asheena Khalakdina ; Vang Ieng ; Tamano Matsui ; Babatunde Olowkure
Western Pacific Surveillance and Response 2022;13(4):24-29
Avian influenza subtype A(HxNy) viruses are zoonotic and may occasionally infect humans through direct or indirect contact, resulting in mild to severe illness and death. Member States in the Western Pacific Region (WPR) communicate and notify the World Health Organization of any human cases of A(HxNy) through the International Health Regulations (IHR 2005) mechanism. This report includes all notifications in the WPR with illness onset dates from 1 November 2003 to 31 July 2022. During this period, there were 1972 human infections with nine different A(HxNy) subtypes notified in the WPR. Since the last report, an additional 134 human avian influenza infections were notified from 1 October 2017 to 31 July 2022. In recent years there has been a change in the primary subtypes and frequency of reports of human A(HxNy) in the region, with a reduction of A(H7N9) and A(H5N1), and conversely an increase of A(H5N6) and A(H9N2). Furthermore, three new subtypes A(H7N4), A(H10N3) and A(H3N8) notified from the People’s Republic of China were the first ever recorded globally. The public health risk from known A(HxNy) viruses remains low as there is no evidence of person-to-person transmission. However, the observed changes in A(HxNy) trends reinforce the need for effective and rapid identification to mitigate the threat of a pandemic from avian influenza if person-to-person transmission were to occur.