| Literature DB >> 33966683 |
Benido Impouma1,2, Franck Mboussou1, Caitlin M Wolfe1,3, Bridget Farham1, George Sie Williams1, Opeayo Ogundiran1, Roland Ngom1, Milse Nzingou1, Antoine Flahault2, Cláudia Torres Codeço4, Ambrose Talisuna1, Zabulon Yoti1, Olivia Keiser2.
Abstract
Successive waves of COVID-19 transmission have led to exponential increases in new infections globally. In this study, we have applied a decision-making tool to assess the risk of continuing transmission to inform decisions on tailored public health and social measures (PHSM) using data on cases and deaths reported by Member States to the WHO Regional Office for Africa as of 31 December 2020. Transmission classification and health system capacity were used to assess the risk level of each country to guide implementation and adjustments to PHSM. Two countries out of 46 assessed met the criteria for sporadic transmission, one for clusters of cases, and 43 (93.5%) for community transmission (CT) including three with uncontrolled disease incidence (Eswatini, Namibia and South Africa). Health system response's capacities were assessed as adequate in two countries (4.3%), moderate in 13 countries (28.3%) and limited in 31 countries (64.4%). The risk level, calculated as a combination of transmission classification and health system response's capacities, was assessed at level 0 in one country (2.1%), level 1 in two countries (4.3%), level 2 in 11 countries (23.9%) and level 3 in 32 (69.6%) countries. The scale of severity ranged from 0 to 4, with 0 the lowest. CT coupled with limited response capacity resulted in a level 3 risk assessment in most countries. Countries at level 3 should be considered as priority focus for additional assistance, in order to prevent the risk rising to level 4, which may necessitate enforcing hard and costly lockdown measures. The large number of countries at level 3 indicates the need for an effective risk management system to be used as a basis for adjusting PHSM at national and sub-national levels.Entities:
Keywords: COVID-19; WHO African region; risk of spread
Mesh:
Year: 2021 PMID: 33966683 PMCID: PMC8712964 DOI: 10.1017/S0950268821001126
Source DB: PubMed Journal: Epidemiol Infect ISSN: 0950-2688 Impact factor: 2.451
Transmission scenarios’ definitions [11]
| Transmission scenario | Definition Countries/territories/areas with |
|---|---|
| No active cases | No new cases detected for at least 28 days (two times the maximum incubation period), in the presence of a robust surveillance system. This implies a near-zero risk of infection for the general population |
| Sporadic cases | Cases detected in the past 14 days are all imported, sporadic (e.g. laboratory-acquired or zoonotic) or are all linked to imported/sporadic cases, and there are no clear signals of further locally acquired transmission. This implies minimal risk of infection for the general population |
| Clusters of cases | Cases detected in the past 14 days are predominantly limited to well-defined clusters that are not directly linked to imported cases but, which are all linked by time, geographic location and common exposures. It is assumed that there are a number of unidentified cases in the area. This implies a low risk of infection to others in the wider community if exposure to these clusters is avoided |
| Community transmission – level 1 (CT1) | Low incidence of locally acquired, widely dispersed cases detected in the past 14 days, with many of the cases not linked to specific clusters; transmission may be focused in certain population sub-groups. Low risk of infection for the general population |
| Community transmission – level 2 (CT2) | Moderate incidence of locally acquired, widely dispersed cases detected in the past 14 days; transmission less focused in certain population sub-groups |
| Community transmission – level 3 (CT3) | High incidence of locally acquired, widely dispersed cases in the past 14 days; transmission widespread and not focused in population sub-groups |
| Community transmission – level 4 (CT4) | Very high incidence of locally acquired, widely dispersed cases in the past 14 days |
Fig. 1.Decision scheme on transmission pattern for countries in the WHO African region.
Indicators and proposed ranges for assessing health system response capacity
| No. | Indicator | Score | ||
|---|---|---|---|---|
| 0 | 1 | 2 | ||
| 1 | Percent of change in new deaths in the past 28 days compared to the previous 28 days | ⩽−50 | >−50 and <20 | ⩾20 |
| 2 | Average number of tests per 100 000 population per week during the last 4 weeks | >200 | 100–200 | <100 |
| 3 | Percent change in new health worker infections in the past 28 days compared to the previous 28 days | ⩽−50 | >−50 and <20 | ⩾20 |
COVID-19 risk for pandemic to continue spreading matrix [11]
| Transmission level | Response capacity | ||
|---|---|---|---|
| Adequate | Moderate | Limited | |
| No cases | Level 0 | Level 0 | Level 1 |
| Imported/sporadic cases | Level 0 | Level 1 | Level 1 |
| Clusters of cases | Level 1 | Level 1 | Level 2 |
| CT with low incidence | Level 1 | Level 2 | Level 2 |
| CT with moderate incidence | Level 2 | Level 2 | Level 3 |
| CT with high incidence | Level 2 | Level 3 | Level 3 |
| CT with uncontrolled incidence | Level 3 | Level 3 | Level 4 |
COVID-19 risk levels’ interpretation and actions recommended
| Risk level | Corresponding situation | Actions recommended |
|---|---|---|
| Level 0 | Situation with no known transmission of SARS-CoV-2 in the preceding 28 days | The health system and public health authorities should be ready to respond and there should be no restrictions on daily activities |
| Level 1 | Situation where the epidemic is controlled through effective measures around the cases or clusters of cases, with limited and transient localised disruption to social and economic life | Surveillance should ensure that any new case can be detected and managed as early as possible, but there should be no restrictions on daily activities |
| Level 2 | Situation with low community incidence or a risk of CT beyond clusters | Measures should be applied to limit the number of social encounters in the community while ensuring services can remain open with safety measures in place |
| Level 3 | Situation of CT with limited additional capacity to respond and a risk of health services becoming overwhelmed | Need to strengthen all PHSM to avoid more stringent restrictions on movement and other related measures applied under level 4. All individuals should reduce their social contacts, and some activities may need to close while allowing for essential services, and in particular schools, to remain open |
| Level 4 | Situation of uncontrolled epidemic with limited or no additional response capacity requiring strong measures for control to avoid large excess mortality and for health services to be overwhelmed | More stringent movement restrictions and related measures may need to be put in place to significantly reduce the time-bound and aimed to be as short as reasonably possible |
Fig. 2.Geographical distribution of countries in the WHO African region by transmission scenario.
Fig. 3.Geographical distribution of countries in the WHO African region by health system's response capacity.
Indicators and reports used to assign a COVID-19 risk level by country in the WHO African region
| Country | Cumulative number of cases | New cases in the past 28 daysa | All cases reported in the last 14 days are imported? | At least 80% of cases reported in the last 14 days are locally transmitted | Epi-link known for at least 80% of cases reported in the last 14 days | Number of cases reported in the past 14 days by million population | % change in new deaths in the past 28 days | Average number of tests per 100 000 population per week during the last 4 weeks | Transmission scenario | Health system's response capacity | Risk level |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Algeria | 99 610 | 13 683 | No | Yes | No | 132 | 10.1 | 30 | CT high incidence | Limited | level_3 |
| Angola | 17 553 | 2192 | No | Yes | No | 37 | 13.5 | 57 | CT moderate incidence | Limited | level_3 |
| Benin | 3251 | 196 | No | Yes | No | 8 | 0 | 29 | CT low incidence | Moderate | level_2 |
| Botswana | 14 805 | 3884 | No | Yes | No | 705 | 16.7 | 1427 | CT high incidence | Moderate | level_3 |
| Burkina Faso | 6828 | 3737 | No | Yes | No | 97 | 20.5 | 27 | CT moderate incidence | Limited | level_3 |
| Burundi | 822 | 130 | No | Yes | No | 5 | 50 | 34 | CT low incidence | Limited | level_2 |
| Cameroon | 26 848 | 2096 | No | Yes | No | 43 | 1.1 | 20 | CT moderate incidence | Limited | level_3 |
| Cape Verde | 11 840 | 902 | No | Yes | No | 615 | 7.1 | 366 | CT high incidence | Moderate | level_3 |
| CAR | 4963 | 36 | No | Yes | No | 3 | 0 | 6 | CT low incidence | Moderate | level_2 |
| Chad | 2113 | 405 | No | Yes | No | 18 | 2.1 | 18 | CT moderate incidence | Limited | level_3 |
| Comoros | 765 | 150 | No | Yes | No | 143 | 22.2 | 8 | CT High incidence | Limited | level_3 |
| Congo | 6200 | 426 | No | Yes | No | 0 | 1.1 | 43 | CT low incidence | Limited | level_2 |
| Cote d'Ivoire | 22 250 | 817 | No | Yes | No | 19 | 3.6 | 36 | CT moderate incidence | Limited | level_3 |
| DRC | 17 658 | 4377 | No | Yes | No | 28 | 17.5 | 4 | CT moderate incidence | Limited | level_3 |
| Eq Guinea | 5277 | 118 | No | Yes | No | 46 | 1.2 | 58 | CT moderate incidence | Limited | level_3 |
| Eritrea | 1320 | 726 | Yes | Not applicable | Not applicable | 180 | 100 | 72 | Sporadic | Moderate | level_1 |
| Eswatini | 9358 | 2884 | No | Yes | Not applicable | 1973 | 43,5 | 948 | CT very high incidence | Moderate | level_3 |
| Ethiopia | 124 264 | 12 685 | No | Yes | No | 52 | 11.2 | 33 | CT moderate incidence | Limited | level_3 |
| Gabon | 9571 | 332 | No | Yes | No | 91 | 6.5 | 1274 | CT moderate incidence | Moderate | level_2 |
| Gambia | 3800 | 32 | No | Yes | No | 6 | 10 | 48 | CT low incidence | Limited | level_2 |
| Ghana | 54 930 | 2656 | No | Yes | No | 42 | 27.8 | 52 | CT moderate incidence | Limited | level_3 |
| Guinea | 13 738 | 552 | No | Yes | No | 18 | 6.2 | 41 | CT moderate incidence | Limited | level_3 |
| Guinea-Bissau | 2447 | 6 | No | Yes | No | 0 | 2.2 | 21 | CT low incidence | Limited | level_2 |
| Kenya | 96 458 | 10 075 | No | Yes | No | 58 | 10.8 | 71 | CT moderate incidence | Limited | level_3 |
| Lesotho | 2577 | 432 | No | Yes | No | 137 | 4.3 | 66 | CT high incidence | Limited | level_3 |
| Liberia | 1800 | 124 | No | Yes | No | 4 | 0 | 32 | CT low incidence | Limited | level_2 |
| Madagascar | 17 714 | 241 | No | Yes | No | 5 | 2.3 | 5 | CT low incidence | Limited | level_2 |
| Malawi | 6583 | 540 | No | Yes | No | 24 | 3.2 | 13 | CT moderate incidence | Limited | level_3 |
| Mali | 7090 | 2210 | No | Yes | No | 53 | 40.8 | 46 | CT moderate incidence | Limited | level_3 |
| Mauritania | 13 642 | 4283 | No | Yes | No | 28 | 12.1 | 217 | CT moderate incidence | Moderate | level_2 |
| Mauritius | 527 | 22 | Yes | Not applicable | Not applicable | 2 | 0 | 401 | Sporadic | Adequate | level_0 |
| Mozambique | 18 642 | 2724 | No | Yes | Not applicable | 46 | 21 | 30 | CT moderate incidence | Limited | level_3 |
| Namibia | 24 545 | 9765 | No | Yes | No | 2607 | 21.2 | 494 | CT very high incidence | Moderate | level_3 |
| Niger | 3208 | 1568 | No | Yes | No | 33 | 1.9 | 16 | CT moderate incidence | Limited | level_3 |
| Nigeria | 87 510 | 19 207 | No | Yes | No | 56 | 8.9 | 21 | CT moderate incidence | Limited | level_3 |
| Rwanda | 8383 | 2372 | No | Yes | No | 107 | 45.5 | 187 | CT high incidence | Moderate | level_3 |
| Sao Tome & Principe | 1014 | 17 | No | Yes | No | 14 | 0 | 141 | CT moderate incidence | Moderate | level_2 |
| Senegal | 19 140 | 2923 | No | Yes | No | 104 | 27 | 55 | CT high incidence | Limited | level_3 |
| Seychelles | 267 | 86 | No | Yes | Yes | 666 | 0 | 4615 | Clusters | Adequate | level_1 |
| Sierra Leone | 2560 | 144 | No | Yes | No | 12 | 1.3 | 56 | CT moderate incidence | Limited | level_3 |
| South Africa | 1 057 561 | 256 689 | No | Yes | No | 2813 | 24.5 | 473 | CT very high incidence | Moderate | level_3 |
| South Sudan | 3558 | 404 | No | Yes | No | 30 | 3.2 | 34 | CT moderate incidence | Limited | level_3 |
| Togo | 3633 | 594 | No | Yes | No | 37 | 3.4 | 81 | CT moderate incidence | Limited | level_3 |
| Uganda | 35 511 | 13 613 | No | Yes | No | 123 | 23 | 64 | CT high incidence | Limited | level_3 |
| Zambia | 20 725 | 2995 | No | Yes | No | 124 | 9.3 | 249 | CT high incidence | Moderate | level_3 |
| Zimbabwe | 13 867 | 3443 | No | Yes | No | 137 | 24.4 | 74 | CT high incidence | Limited | level_3 |
CT, community transmission.
aLast 28 days (4–31 December 2020).
Last 14 days (18–31 December 2020).
Fig. 4.Geographical distribution of countries in the WHO African region by COVID-19 risk level.