Why lockdown? Simplified arithmetic tools for decision-makers, health professionals, journalists and the general public to explore containment options for the novel coronavirus

Gerry Killeen; Samson Kiware

All these delays, truncations or inadequacies of lock down, or imperfections of importation containment, result in failure to eliminate local transmission that then rebounds and rapidly spirals out of control without a second full containment campaign ( Figure 2 ). The implications of such an uncontained rebound scenario are essentially identical to doing nothing in the first place: In all cases, 99% of the population is expected to become infected over about a year, resulting in approximately 540,000 deaths and ICU demand exceeding capacity about 800 times over. It is also worth noting that total national hospital inpatient capacity of approximately 50,000 beds 80 would be overwhelmed by cases of severe COID-19 disease peaking at 2.3 million over a three-week period. Under such conditions of a full-blown public health catastrophe, the mitigating effect of stronger health systems in high income countries are largely negated, so our predictions of over half a million deaths in Tanzania compare well with those of others for the United Kingdom, 29 which has a similar population size. Considering also the travel distances and household costs of hospital attendance in Tanzania [81] [82] [83] [84] , it also raises the question as to whether severe COVID patients should be cared for in hospitals and other health facilities [85] [86] [87] [88] which are already 52% understaffed 89 or at home [85] [86] [87] [88] with support from a rapidly mobilized cadre of Community Health Workers, for which well-characterized curricula and training platforms already exist. [90] [91] [92] (1) shortening the lock down period by 3 weeks, from 15 to 12 weeks (Panels A and B), (2) reducing importation containment from 100% to 90%, (3) delaying the lock down by 3 weeks (Panels C and D), starting on week 8 rather than week 5 (Panels E and F), and (4) reducing the coverage and protective effectiveness of exposure behaviour reduction from 90% to 80% (Panels G and H). is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.