The Identification of First COVID-19 Cluster in Indonesia

Abstract

We describe the first 11 detected COVID-19 cases in Indonesia, resulting from a local transmission occurring in a club and a restaurant. The virus was detected until an average of 21.3 days (range: 11-25, SD: 4.1) after the onset of illness, and the partial N gene sequences (28,321-28,707 nucleotide position) had 100% similarity with the SARS-CoV-2 sequence from Wuhan. Two subjects were asymptomatic, and one subject has died.

Figure 1.

SARS-CoV-2 transmission pattern, incubation period, serologic conversion, and hospitalization days of first Indonesia’s cluster.

Figure 2.

Molecular characterization of symptomatic (left) and asymptomatic (right) cases. The kinetics of virus in serial respiratory specimens (ct value, Y-axis). Symptomatic cases (nine patients) were displayed based on the day of symptoms, whereas asymptomatic cases (two patients) were displayed based on the day of exposure.

Figure 3.

Neighbor-joining phylogenetic tree for two samples from the first cluster in Indonesia (indicated with solid circles). The phylogenetic analysis was performed based on 387 bp of the partial N region. The nucleotide sequences obtained from direct sequencing and the reference sequences retrieved from the GISAID database were aligned with Clustal X software (http://clustal.org/clustal2/). The evolutionary distances were computed using the maximum composite likelihood method. The analyses were performed using Molecular Evolutionary Genetics Analysis software version 7 (https://www.megasoftware.net/).