Contact tracing: a lesson from the Nipah virus in the time of COVID-19

Abstract

Without a vaccine or proven therapeutic options in COVID-19, the World Health Organization (WHO) recommends a combination of measures: rapid diagnosis and immediate isolation of cases; rigorous contact tracing; and precautionary self-isolation of close contacts to curb the spread of COVID-19. During a Nipah outbreak in Kerala, India in 2019, it was confined to a single case. The authors were involved in the in-hospital contact tracing. With a single patient producing a contact list of 98 in a healthcare setting, the implications in a community setting during a pandemic of the scale of COVID-19 are huge but it proves that early and rigorous tracing with quarantining is an effective strategy to limit clusters. We believe that if the public is encouraged to maintain their own contact list on a daily basis, it would help in significantly reducing the time and effort invested into contact tracing in the event of a person contracting COVID-19.

Effectiveness of Contact Tracing for Viral Disease Mitigation and Suppression: Evidence-Based Review

“…Most studies (n=14) [ 13 , 16 , 18 , 19 , 21 - 23 , 26 - 28 , 30 , 31 , 34 , 35 ] used mathematical modeling, but others were observational studies (n=8) [ 14 , 15 , 20 , 24 , 29 , 32 , 33 , 36 ] and systematic reviews (n=2) [ 17 , 25 ]. These modeling studies used synthetic populations to provide quantitative analyses primarily of COVID-19 evolution to query the effectiveness of contact tracing with other interventions.…”

“…These modeling studies used synthetic populations to provide quantitative analyses primarily of COVID-19 evolution to query the effectiveness of contact tracing with other interventions. Identified study settings were global [ 16 , 17 , 25 , 28 , 32 ], nonspecified [ 19 , 22 , 27 , 31 ], or included the following countries: Canada [ 30 , 35 ], China [ 36 ], India [ 33 ], Korea [ 20 , 29 ], Taiwan [ 14 , 24 ], United Kingdom [ 15 , 18 , 21 , 23 ], and the United States [ 13 , 26 , 34 ]. Intervention duration varied across the studies, and both children and adults were targeted.…”

“…Intervention duration varied across the studies, and both children and adults were targeted. SARS-CoV-2 (n=18) was the most frequently examined viral outbreak [ 13 , 14 , 16 - 19 , 21 - 24 , 26 , 27 , 29 - 32 , 34 , 35 ], but Nipah virus (n=1) [ 33 ] and various influenza A hemagglutinin (H) and neuraminidase (N) subtypes, including H1N1 (n=4) [ 17 , 25 , 28 , 36 ] and H7N2 (n=1) [ 15 ], were also studied.…”

“…Viral disease outcomes associated with the effectiveness of contact tracing were limited to disease incidence, hospitalization, mortality, and transmission ( Table 1 ). The most frequently reported outcomes were transmission (n=19) [ 13 , 15 - 27 , 30 - 32 , 34 , 35 ] and incidence (n=9), [ 13 - 17 , 24 , 28 , 29 , 33 ] whereas hospitalization and mortality outcomes were described in only 3 studies [ 13 , 18 , 26 ]. All studies reported some degree of effectiveness for contact tracing examined across mild to moderate (R0<1.5) and/or moderate to severe (R0≥1.5) epidemics or pandemics based on the provided R0.…”

Dealing With COVID-19 Pandemic: Key Learnings From Kerala

“…This is not quite unexpected since the state had earlier faced a crucial test of substantial public health care system while combating the Nipah virus outbreak in 2018. 1…”