Identification of transmission chains and clusters associated with COVID-19 in Tunisia.
COVID-19
Cluster analysis
Contact tracing
Coronavirus infections / transmission
Public health
Tunisia
Journal
BMC infectious diseases
ISSN: 1471-2334
Titre abrégé: BMC Infect Dis
Pays: England
ID NLM: 100968551
Informations de publication
Date de publication:
19 May 2021
19 May 2021
Historique:
received:
13
10
2020
accepted:
22
04
2021
entrez:
20
5
2021
pubmed:
21
5
2021
medline:
2
6
2021
Statut:
epublish
Résumé
The aim of this study was to characterize the transmission chains and clusters of COVID-19 infection in Tunisia. All cases were confirmed by Reverse Transcriptase Polymerase Chain Reaction of a nasopharyngeal specimen. Contact tracing is undertaken for all confirmed cases in order to identify close contacts that will be systematically screened and quarantined. Transmission chains were identified based on field investigation, contact tracing, results of screening tests and by assessing all probable mode of transmission and interactions. As of May 18, 2020, 656 cases out of a total of 1043 confirmed cases of Coronavirus disease 2019 belong to 127 transmission chains identified during the epidemic (mean age 42.36 years, Standard deviation 19.56 and sex ratio 0.86). The virus transmission is the most concentrated in the governorate of Tunis (31.5%), Ariana (10.2%) and Ben Arous (10.2%). Virus transmission occurred 50 times (9.72% of secondary transmission events) between two different governorates. A maximum of seven generations of secondary infection was identified, whereas 62% of these secondary infections belong the first generation. A total of 11 "super spreader" cases were identified in this investigation. Four large clusters have been identified. The evolution of secondary cases highlighted two peaks: one in 2nd April and a second in 16 Correct contact tracing and early active case finding is useful to identify transmission chains and source of infection in order to contain the widespread transmission in the community.
Sections du résumé
BACKGROUND
BACKGROUND
The aim of this study was to characterize the transmission chains and clusters of COVID-19 infection in Tunisia.
METHODS
METHODS
All cases were confirmed by Reverse Transcriptase Polymerase Chain Reaction of a nasopharyngeal specimen. Contact tracing is undertaken for all confirmed cases in order to identify close contacts that will be systematically screened and quarantined. Transmission chains were identified based on field investigation, contact tracing, results of screening tests and by assessing all probable mode of transmission and interactions.
RESULTS
RESULTS
As of May 18, 2020, 656 cases out of a total of 1043 confirmed cases of Coronavirus disease 2019 belong to 127 transmission chains identified during the epidemic (mean age 42.36 years, Standard deviation 19.56 and sex ratio 0.86). The virus transmission is the most concentrated in the governorate of Tunis (31.5%), Ariana (10.2%) and Ben Arous (10.2%). Virus transmission occurred 50 times (9.72% of secondary transmission events) between two different governorates. A maximum of seven generations of secondary infection was identified, whereas 62% of these secondary infections belong the first generation. A total of 11 "super spreader" cases were identified in this investigation. Four large clusters have been identified. The evolution of secondary cases highlighted two peaks: one in 2nd April and a second in 16
CONCLUSION
CONCLUSIONS
Correct contact tracing and early active case finding is useful to identify transmission chains and source of infection in order to contain the widespread transmission in the community.
Identifiants
pubmed: 34011266
doi: 10.1186/s12879-021-06107-6
pii: 10.1186/s12879-021-06107-6
pmc: PMC8132040
doi:
Substances chimiques
RNA, Viral
0
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
453Références
N Engl J Med. 2003 May 15;348(20):1977-85
pubmed: 12671062
Tunis Med. 2020 Apr;98(4):258-260
pubmed: 32395787
Lancet Glob Health. 2020 Apr;8(4):e488-e496
pubmed: 32119825
Lancet. 2003 May 24;361(9371):1767-72
pubmed: 12781535
Clin Infect Dis. 2016 Feb 15;62(4):477-483
pubmed: 26565003
J Korean Med Sci. 2017 May;32(5):744-749
pubmed: 28378546
BMC Infect Dis. 2020 Dec 2;20(1):914
pubmed: 33267823
Lancet. 2016 Sep 3;388(10048):994-1001
pubmed: 27402381
BMJ. 2020 Feb 19;368:m627
pubmed: 32075791
Emerg Microbes Infect. 2020 Dec;9(1):386-389
pubmed: 32065057
Lancet Infect Dis. 2020 Jul;20(7):809-815
pubmed: 32330439
JAMA. 2020 Apr 28;323(16):1610-1612
pubmed: 32129805
Infect Dis Model. 2020 Feb 29;5:264-270
pubmed: 32190785