A study of the dynamics of the second wave of COVID epidemic, specifically for each state and every district is made available at https://tiny.cc/covid-momentum website. The onset, progression, peak and decline vary from district to district in each State.
There are three parameters pertaining to the epidemic, each with its own wave and peak, namely epidemic momentum (rate of change in new cases based on a 7 -day rolling average), documented daily numbers of new cases and cumulative numbers of active cases. Typically, there is a consistent pattern of time sequence of these three peaks – momentum, new case numbers and active cases. Visualizing the time of these peaks in a given district will enable health administrators to take appropriate action vis-à-vis the lockdown.
Lockdown is most effective in slowing down the epidemic momentum only on the ascending limb of the momentum graph. Well-timed lockdown provides time to prepare for surge capacity -- hospital beds, Intensive care (ICU) beds, supply of oxygen and essential drugs. During this time, the focus should be on effective application of ‘social vaccine’ and to rapidly increase immunization coverage – these will help reduce the rapid progression of the epidemic.
Social vaccine consists of Information-Education-Communication on COVID and Behavior-modification Education for adopting all elements of COVID-appropriate behavior -- mask-wearing, hand hygiene, physical distancing of arm’s length when all are masked, avoiding crowds and improving indoor-ventilation during any activity.
Lock-down should be relaxed when the three peaks are over, as illustrated below. For the attention of administrators there are two more parameters to study: mortality acceleration and numbers of daily deaths. Once number of daily deaths also peaks and declines, everyone can relax, lock-down can be eased gradually and carefully but the tempo of COVID immunization and adherence to COVID appropriate behavior should be sustained.
Once the numerical mortality peak is over, the district/State will have surplus supply of essential necessities of hospitals, especially medicines and oxygen concentrators– they should be shared with needy neighbors.
We provide the epidemic graphs for Puducherry and Karaikkalas typical examplesof districtswhere all the peaks are over and mortality (available at https://tiny.cc/covid-momentum web-site ) has also come down. Careful relaxation of curbs can be introduced.
In all thedistricts of Puducherry, all three peaks are over; in addition, even mortality acceleration and numerical mortality peak are over. Hospitals can expect COVID admissions to progressively come down; they can start admitting non-COVID patients for elective treatment and surgery. They should however continue focus on social vaccine and increase immunization coverage.
- M S Seshadri is former Professor of Medicine and Clinical Endocrinology, Christian Medical College, Vellore, and currently Medical Director, Thirumalai Mission Hospital, Ranipet.
- Muru Subramani is former CTO at GlobalScholar and Research Engineer at Microsoft Research, Redmond, and currently Researcher, BhaktivedantaVidhyapitha Research Center, Mumbai.
- T Jacob John is former Professor of Clinical Virology, Christian Medical College, Vellore