Decreased dengue transmission in migrant worker populations in Singapore attributable to SARS-CoV-2 quarantine measures

Abstract

Background We examined the impact of SARS-CoV-2 social distancing and quarantine policies on dengue transmission in the general and migrant worker populations in Singapore. Methods We utilized all nationally reported dengue cases in the general and migrant worker populations from 1 January 2013 to 31 May 2020. A difference-in-difference identification strategy was used to determine the effects of social distancing and quarantine policies on reported dengue case counts over time, whilst controlling for weather patterns, seasonality, age and population size. Results A reduction of 4.8 dengue cases per age band among migrant workers was attributable to quarantine policies, corresponding to a total reduction of around 432 reported dengue cases over 10 weeks. In the general working population, an increase of 14.5 dengue cases per age band was observed, which corresponds to a total increase of around 1450 reported dengue cases in the same time period. There is an expected relative risk reduction in dengue transmission for the migrant worker population at 0.635 due to quarantine policy and a relative risk increase for the general working population due to social distancing policies at 0.685. Conclusions Migrant workers experienced a reduced risk of dengue when they were confined to their dormitories as part of the COVID-19 social distancing measures. Our study highlights the vulnerability of migrant workers under normal working conditions.

Health of International Migrant Workers During the COVID-19 Pandemic: A Scoping Review

“…Of the 26 included studies ( 24 – 49 ) almost half (12 of 26) were conducted in Asia ( 24 , 26 , 30 , 32 – 35 , 37 , 41 , 44 , 47 , 49 ) and 8 in Europe. Fourteen papers used a quantitative design ( 24 , 27 , 28 , 30 , 32 , 33 , 35 , 36 , 40 , 42 – 44 , 46 , 48 ), 5 applied mixed methods ( 29 , 31 , 34 , 38 , 45 ) and 23 used primary data sources ( 24 – 29 , 31 , 32 , 34 , 36 – 49 ) ( Table 2 ).…”

“…Most immigrant populations represented in the studies originated from countries in Asia (16 of 26 studies) ( 24 , 26 , 27 , 31 – 34 , 37 , 38 , 41 – 44 , 47 – 49 ) and Latin America (8 of 26) ( 25 , 28 , 29 , 38 , 39 , 42 , 44 , 46 ). Other characteristics of the studied populations were often not described in the methodology of the papers: only 9 studies clearly described migrants' length of stay in the host country ( 24 , 27 , 31 , 32 , 37 , 39 , 41 , 43 , 48 ), most of which were long stays (five or more years) and migrants' legal status was not specified in 20 studies ( 26 – 30 , 32 – 34 , 36 , 37 , 39 , 40 , 42 – 49 ). Seven studies had a comparison group ( 29 , 30 , 33 , 35 , 36 , 40 , 45 ), most frequently the majority population (6 of 7 studies) ( 30 , 33 , 35 , 36 , 40 , 45 ).…”

Implication of Social Restrictions on Covid-19 Pandemic Towards Dengue Control: Literature Review

“…The results showed that social restrictions were associated with an increase in DHF cases reported in Singapore. One of the main avenues that could explain this result is the increase in time spent at home addresses due to social distancing policies and the tendency for dengue infection to occur at home rather than at office addresses in Singapore [24].Although workplace infections may surface, it was found that, in many areas, the place of residence is the most common site of vector-borne disease infection rather than the workplace. The concentration of vector breeding sites in the vicinity of residential areas further increases the risk of transmission in these sites compared to workplaces.…”

Economic impact of dengue in Singapore from 2010 to 2020 and the cost-effectiveness of Wolbachia interventions

“…Due to extensive investments into vector control, the force of infection is estimated to have rapidly declined from the late 1960s to the mid-1990s, after which the force of infection remained stable [15]. However, persistent outbreaks continue to occur in multi-year cycles [16,17], with the recent 2020 dengue outbreak recording an alltime high of 1,792 weekly cases [18]. This demonstrates the limits of conventional vector control measures such as breeding site elimination and fogging, as well as the importance of evaluating other potential novel vector control strategies, such as Wolbachia.…”