Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Nov 9;13(1):20.
doi: 10.1186/s12976-016-0046-1.

Estimating the subcritical transmissibility of the Zika outbreak in the State of Florida, USA, 2016

Linh Dinh  1 , Gerardo Chowell  1   2 , Kenji Mizumoto  3   4 , Hiroshi Nishiura  5   6
Affiliations

Estimating the subcritical transmissibility of the Zika outbreak in the State of Florida, USA, 2016

Linh Dinh et al. Theor Biol Med Model. .

Abstract

Background: Florida State has reported autochthonous transmission of Zika virus since late July 2016. Here we assessed the transmissibility associated with the outbreak and generated a short-term forecast.

Methods: Time-dependent dynamics of imported cases reported in the state of Florida was approximated by a logistic growth equation. We estimated the reproduction number using the renewal equation in order to predict the incidence of local cases arising from both local and imported primary cases. Using a bootstrap method together with the logistic and renewal equations, a short-term forecast of local and imported cases was carried out.

Results: The reproduction number was estimated at 0.16 (95 % Confidence Interval: 0.13, 0.19). Employing the logistic equation to capture a drastic decline in the number of imported cases expected through the course of 2016, together with the low estimate of the local reproduction number in Florida, the expected number of local reported cases was demonstrated to show an evident declining trend for the remainder of 2016.

Conclusions: The risk of local transmission in the state of Florida is predicted to dramatically decline by the end of 2016.

Keywords: Basic reproduction number; Epidemic; Mathematical model; Prediction; Zika virus.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Observed weekly counts of confirmed cases of Zika virus infection, Florida, 2016. Imported cases have travel history to a country with widespread Zika virus transmission, while local cases were considered to arise from mosquito-borne transmission within Florida. Weekly counts start on 1 May 2016 and week 34 represents the last week of 2016
Fig. 2
Fig. 2
Observed and predicted time-dependent dynamics of Zika virus infection, Florida, 2016. a. Imported cases and b. local cases. Continuous line in a and dotted line in b represents the predicted results from maximum likelihood estimates of the reproduction number and parameters for logistic equation. Dashed lines in both panels from week 22 to 34 represent the prediction interval based on a Bootstrap method. Weekly counts start on 1 May 2016 and week 34 represents the last week of 2016
See this image and copyright information in PMC

References

    1. Centers for Disease Control and Prevention (USA). Florida investigation links four recent Zika cases to local mosquito-borne virus transmission [Internet]. Accessed 7 Nov 2016. Available from: http://www.cdc.gov/media/releases/2016/p0729-florida-zika-cases.html
    1. Florida Department of Health (USA). Department of Health Daily Zika Update, 26 September 2016 [Internet]. Accessed 7 Nov 2016. Available from: http://www.floridahealth.gov/newsroom/2016/09/092616-zika-update.html
    1. Florida Department of Health (USA). Department of Health’s Zika testing, investigation and notification process [Internet]. Accessed 7 Nov 2016. Available from: http://www.floridahealth.gov/diseases-and-conditions/zika-virus/_documen...
    1. Majumder MS, Cohn E, Fish D, Brownstein JS. Estimating a feasible serial interval range for Zika fever. Bull WHO. 2016;in press. doi:10.2471/BLT.16.170860
    1. Roberts MG, Nishiura H. Early estimation of the reproduction number in the presence of imported cases: pandemic influenza H1N1-2009 in New Zealand. PLoS One. 2011;6:e17835. doi: 10.1371/journal.pone.0017835. - DOI - PMC - PubMed

Publication types

MeSH terms