Pandemic-associated mobility restrictions could cause increases in dengue virus transmission

Background The COVID-19 pandemic has induced unprecedented reductions in human mobility and social contacts throughout the world. Because dengue virus (DENV) transmission is strongly driven by human mobility, behavioral changes associated with the pandemic have been hypothesized to impact dengue incidence. By discouraging human contact, COVID-19 control measures have also disrupted dengue vector control interventions, the most effective of which require entry into homes. We sought to investigate how and why dengue incidence could differ under a lockdown scenario with a proportion of the population sheltered at home. Methodology & principal findings We used an agent-based model with a realistic treatment of human mobility and vector control. We found that a lockdown in which 70% of the population sheltered at home and which occurred in a season when a new serotype invaded could lead to a small average increase in cumulative DENV infections of up to 10%, depending on the time of year lockdown occurred. Lockdown had a more pronounced effect on the spatial distribution of DENV infections, with higher incidence under lockdown in regions with higher mosquito abundance. Transmission was also more focused in homes following lockdown. The proportion of people infected in their own home rose from 54% under normal conditions to 66% under lockdown, and the household secondary attack rate rose from 0.109 to 0.128, a 17% increase. When we considered that lockdown measures could disrupt regular, city-wide vector control campaigns, the increase in incidence was more pronounced than with lockdown alone, especially if lockdown occurred at the optimal time for vector control. Conclusions & significance Our results indicate that an unintended outcome of lockdown measures may be to adversely alter the epidemiology of dengue. This observation has important implications for an improved understanding of dengue epidemiology and effective application of dengue vector control. When coordinating public health responses during a syndemic, it is important to monitor multiple infections and understand that an intervention against one disease may exacerbate another.

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The impacts of COVID-19 mitigation on dengue virus transmission: a modelling study

10.1101/2020.11.17.20210211 ◽

2020 ◽

Author(s):

Sean M Cavany ◽

Guido España ◽

Gonzalo M Vazquez-Prokopec ◽

Thomas W Scott ◽

T Alex Perkins

Keyword(s):

Dengue Virus ◽

Vector Control ◽

Human Mobility ◽

Control Measures ◽

Optimal Time ◽

Multiple Infections ◽

Dengue Vector ◽

Mosquito Abundance ◽

Dengue Vector Control ◽

At Home

SummaryBackgroundThe COVID-19 pandemic has induced unprecedented reductions in human mobility and social contacts throughout the world. Because dengue virus (DENV) transmission is strongly driven by human mobility, behavioral changes associated with the pandemic have been hypothesized to impact dengue incidence. By discouraging human contact, COVID-19 control measures have also disrupted dengue vector control interventions, the most effective of which require entry into homes.MethodWe used an agent-based model with a realistic treatment of human mobility and vector control to investigate how and why dengue incidence could differ under a lockdown scenario with a proportion of the population sheltered at home.ResultWe found that a lockdown in which 70% of the population sheltered at home led to a small average increase in cumulative DENV infections of up to 10%, depending on the time of year lockdown occurred. Lockdown had a more pronounced effect on the spatial distribution of DENV infections, with higher incidence under lockdown in regions with high mosquito abundance. Transmission was also more focused in homes following lockdown. The proportion of people infected in their own home rose from 54% under normal conditions to 66% under lockdown, and the household secondary attack rate rose from 0.109 to 0.128, a 17% increase. When we considered that lockdown measures could disrupt regular, city-wide vector control campaigns, the increase in incidence was more pronounced than with lockdown alone, especially if lockdown occurred at the optimal time for vector control.DiscussionOur results indicate that an unintended outcome of COVID-19 control measures may be to adversely alter the epidemiology of dengue. This observation has important implications for an improved understanding of dengue epidemiology and effective application of dengue vector control. When coordinating public health responses during a syndemic, it is important to monitor multiple infections and understand that an intervention against one disease may exacerbate another.

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Challenges and future perspective for dengue vector control in the Western Pacific Region

Western Pacific Surveillance and Response ◽

10.5365/wpsar.2010.1.1.012 ◽

2011 ◽

Vol 2 (2) ◽

pp. e1-e1 ◽

Cited By ~ 14

Author(s):

Moh Seng Chang ◽

Eva Maria Christophel ◽

Deyer Gopinath ◽

Rashid Md Abdur

Keyword(s):

Vector Control ◽

Western Pacific ◽

Future Perspective ◽

Pacific Region ◽

Dengue Vector ◽

Western Pacific Region ◽

The Western Pacific ◽

Dengue Vector Control

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Assessment of Aedes aegypti Pupal Productivity during the Dengue Vector Control Program in a Costal Urban Centre of São Paulo State, Brazil

Journal of Insects ◽

10.1155/2014/301083 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Marylene de Brito Arduino

Keyword(s):

Vector Control ◽

Large City ◽

Control Program ◽

Sao Paulo ◽

São Paulo ◽

Dengue Vector ◽

Urban Centre ◽

Vector Control Program ◽

Productivity Indices ◽

Dengue Vector Control

The control of dengue relies on the elimination of vector breeding sites. This study identified the container categories most productive for A. aegypti within the framework of the São Paulo dengue vector control program (DVCP) in São Sebastião, a large city located on the state’s coast where dengue cases have occurred since 2001. Containers were inspected monthly for the occurrence of mosquito immature stages during two consecutive vector-breeding seasons in 2002–2004. Containers were classified by their material, use, and fixed or removable status. Pupal productivity differed significantly among container types, items made of metal and plastic, and boats being those with the highest relative contribution. Significant correlations between traditional indices of A. aegypti abundance (Container Index, House Index, and Breteau Index) and pupal productivity/demographic indices (Pupae/Container, Pupae/House, Pupae/ha, and Pupae/Person) ranged 0.56–0.65; correlations were not statistically significant for any combination involving the Pupae/Container index. The assessment of pupal productivity indices could be incorporated into the DVCP without any additional operational onus, allowing vector control managers to determine appropriate control actions targeting the most productive containers and sites. Further studies are needed to assess whether pupal productivity indices may be used as epidemiological indicators of risk of dengue transmission.

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