Quick Literature Preview on COVID-19 Mass Testing and Contact Tracing: Lessons for Philippine Policymakers

Experts are united in emphasizing that the most basic weapons to help control (if not eradicate) the pandemic include mass testing and contact tracing.

Experts are also united in pointing out that the Philippines is far from achieving ideal mass testing goals and lacks an effective and unified contact tracing system.

Vaccination is important but no panacea for the pandemic. Even if all Filipinos were to be vaccinated in the next few months, mass testing and contact tracing would have to be maintained.

Hence, this quick literature preview (rather than review; as this note features mostly direct quotes from researches) is aimed at providing a summary of practical insights and/or recommendations culled from mostly peer-reviewed literature on mass testing and contact tracing – to help our policymakers “science the shit out of this” so to speak. All emphases are supplied.

“Bidirectional contact tracing could dramatically improve COVID-19 control” (Bradshaw et al., 2021)

1. “…‘bidirectional” tracing to identify infector individuals and their other infectees robustly improves outbreak control…”
2. “The greatest gains are realised by expanding the manual tracing window from 2 to 6 days pre-symptom-onset or, alternatively, by implementing high-uptake smartphone-based exposure notification…” 
3. “Hybridizing manual tracing with digital may offer an alternative path to high performance. In practice, almost no jurisdiction is proposing to exclusively control COVID-19 through digital exposure notification, but rather to supplement traditional manual tracing with digital tools. The two methods have complementary strengths and weaknesses: digital tracing is fast, scalable, and could be easily adapted to trace bidirectionally, but is highly fragile to network fragmentation; manual tracing is slower and more labor-intensive, but more robust. A hybrid of the two approaches might thus outperform either approach used in isolation.”

“Impact of delays on effectiveness of contact tracing strategies for COVID-19: a modelling study” (Kretzschmar et al., 2020)

1. “…a contact tracing strategy will only contribute to containment of COVID-19 if it can be organised such that delays in the process from symptom onset to isolation of the index case and their contacts are very short…Reducing delay in testing individuals for SARS-CoV-2 should be a key objective of a contact tracing strategy…”
2. “For example, walk-in or drive-in testing facilities could be set up on a large scale and test results immediately communicated via the tracing app.”

“Modelling the impact of testing, contact tracing and household quarantine on second waves of COVID-19” (Aleta et al., 2021)

1. “a period of strict social distancing followed by a robust level of testing, contact-tracing and household quarantine could keep the disease within the capacity of the healthcare system while enabling the reopening of economic activities. Our results show that a response system based on enhanced testing and contact tracing can have a major role in relaxing social-distancing interventions in the absence of herd immunity against SARS-CoV-2.”

“Why Contact Tracing Efforts Have Failed to Curb Coronavirus Disease 2019 (COVID-19) Transmission in Much of the United States” (Clark et al., 2020)

1. Reasons “why contact tracing efforts have failed to curb” the pandemic in “much of the United States” include: “A LACK OF NATIONAL COORDINATION” and “INADEQUATE TESTING SUPPLY”
2. “Larger numbers of staff may be necessary as social distancing measures are loosened (or public adherence decreases) and case counts increase, or if technologic tools are not used for augmentation. Smaller numbers of staff would likely be necessary if local, state, and national public health agencies were able to communicate and coordinate effectively. Creation of a national contact tracing system could eliminate geographic restrictions for hiring and would increase procedural standardization.”

“Successful find-test-trace-isolate-support systems: how to win at snakes and ladders” (Rajan et al., 2020)

1. Isolation is arguably the most important part of the test, trace, isolate process according to recent evidence. A team of community volunteer contact tracers in the UK published data  from a pilot in which it took approximately 80 minutes to manage each case, with many contacts were unwilling to isolate…Measures to support isolation are therefore an important ladder and in Denmark, Finland and Lithuania, people who cannot isolate are accommodated elsewhere… The same approach has also been used successfully to prevent outbreaks in care homes in South Korea. Without facilities to support vulnerable individuals to isolate, and especially to minimise any loss of income, it is likely that transmission will rise, another snake that could set back the entire process.”

“An Empirical Argument for Mass Testing: Crude Estimates of Unreported COVID19 Cases in the Philippines vis-à-vis Others in the ASEAN-5” (Cruz, 2020)

1. “…the empirical estimates buttress the argument that the mere extension of the lockdown without complementary mass testing is impractical…the inevitable policy direction for the Philippines is to aggressively implement the WHO recommendation of “test, trace, and isolate” to avoid long-term health and economic distress.”

Other Commonsensical Ideas Worth Trying:

1. Offer full wage/salary subsidy – from diagnosis until full recovery – to workers who will test positive to encourage people to undergo testing.
2. In the duration of the ECQ, offer full wage/salary subsidy for workers in the NCR Plus areas to encourage those in industries allowed to operate with skeletal workforces to take a break and stay at home.
3. In the duration of the ECQ, offer living income subsidy for informal economy workers (especially ambulant vendors and the like) to encourage them to stay at home.  
4. Swiftly build makeshift hospitals for COVID-19 patients in NCR Plus areas and other areas where hospital occupancy rates are nearing 90%
5. To expand health care workforce, train auxiliary health workers and offer all public health workers double pay at least during the pandemic.
6. In the duration of the ECQ (and even better, beyond the ECQ), ban all international and domestic air travel – except for essential workers (nurses, doctors etc.) and offer full wage subsidy for affected workers

P.S. Yes, these are costly measures but we have the money (pandemic loans) and the alternative is worse: permanent pandemic and economic crisis.   

Notes/References:

1. Phrase “science the shit out of this” is from the movie “The Martian.”   
2. Bradshaw et al., 2021: https://www.nature.com/articles/s41467-020-20325-7
3. Kretzschmar et al., 2020: https://www.sciencedirect.com/science/article/pii/S2468266720301572
4. Aleta et al., 2020: https://www.nature.com/articles/s41562-020-0931-9
5. Clark et al., 2020: https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1155/5881818?login=true
6. Rajan et al., 2020: https://apps.who.int/iris/bitstream/handle/10665/336292/Eurohealth-26-2-34-39-eng.pdf
7. Cruz, 2020: http://ateneo.edu/sites/default/files/downloadable-files/ADMU%20WP%202020-14.pdf