The COVID-19 pandemic, a biological hazard

The COVID-19 pandemic is due to a novel coronavirus which has been named Sars-Cov-2. It is an emerging zoonosis. Although its animal origin is not precise enough, the pangolin, the snake, and the turtle are suspected due to the interaction between their cell surface protein angiotensin-converting enzyme 2 (ACE 2) with a protein from the 2019-Sars-Cov-2 virus.

The origin of the crossing of the species barrier, the passage from animal to human, raises a lot of debate. ^{Reference Liu, Xiao and Wei12} In-depth studies on forest and domestic fauna and production chains in the Central African sub-region must be carried out on the circulation of coronaviruses in animals and reservoirs. This virus has a great tropism for the cells of the upper and lower respiratory mucous membranes in which it multiplies. The COVID-19 incubation period ranges from 2 to 14 days. ^{Reference Linton, Kobayashi and Yang13} Apart from asymptomatic carriers who represent 1.2% of patients, ¹⁴ the most frequent symptoms are fever, cough, difficulty in breathing, fatigue, muscle pain, and more rarely, gastrointestinal signs. Thus, the clinical picture can range from a common flu-like syndrome to severe respiratory distress that can progress to multiple organ failure. ^{Reference Guan, Ni and Hu15,Reference Rothan and Byrareddy16}

Sars-Cov-2 is characterized by its great contagiousness, which explains the rapid increase in the number of cases worldwide. Till date 6028135 confirmed cases have been reported in 188 countries in just 5 months, approximately 200 times the number of cases observed during the Ebola epidemic between 2014 and 2016 in West Africa. ^3,17 The Ebola virus is mainly transmitted by contact with the patient’s body fluids, ¹⁷ while COVID-19 is transmitted from 1 person to another by air through droplets, personal contact, and contamination of objects. ^{Reference Rothan and Byrareddy16} Cases of COVID-19 transmission by asymptomatic and pre-symptomatic patients have been reported by some authors, ^{Reference Bai, Yao and Wei18,Reference Rothe, Schunk and Sothmann19} as well as few cases of reactivation of the virus after recovery. ^{Reference Ye, Pan and Pan20} The evidence for reinfection in recovered patients is not yet clarified at this date. ^{Reference Omer, Malani and del Rio21}

The virulence of Sars-cov-2 has already caused more than 368944 deaths in the world in just 5 months, the overall lethality rate is 6.12%, varying from 1 country to another according to local resilience capacities. This number of deaths in just 5 months represents more than 33 times the number of deaths observed with the Ebola outbreak that lasted from 2014 to 2016 in West Africa, which had a much greater lethality rate of 39.5%. ^3,17 This difference is explained by the high number of cases of COVID-19.

Another important characteristic of this virus is its resistance, as droplets, particularly those emitted during sneezing can be projected up to 2 to 4 meters and the virus can persist there for up to 45 minutes depending on the conditions of temperature and pressure. Its survival on surfaces, which is limited to a few minutes on the skin, can continue for up to 12 hours on clothing and 5 days on paper, metal, and plastic. SARS-CoV-2 is sensitive to ultraviolet rays and heat and can be inactivated by lipid solvents including ether (75%), ethanol, chlorine-containing disinfectant, peroxyacetic acid, and chloroform (except for chlorhexidine). ^{Reference Kampf, Todt and Pfaender22}

Despite the previous data on other coronaviruses like MERS-CoV ^{Reference Altamimi and Ahmed23} and the spread which seems to be slower in sub-Saharan Africa than in Europe, North America, and a part of Asia, the seasonality of cases and slower transmission in warmer climates is highly contested. All this is with respect to the ongoing situation in Southern US, India, Indonesia. ³ Nevertheless, such biological and epidemiological characteristics make the SARS-Cov-2 coronavirus a threat to all humanity. The statistical features of the COVID-19 pandemic seem to present the same trend in the 5 African sub-regions with 2157 deaths/48454 cumulative cases in Northern Africa, 686 deaths/33029 cumulative cases in Southern Africa, 266 deaths/15589 cumulative cases in Eastern Africa, 740 deaths/35555 cumulative cases in Western Africa, and 397 deaths/16337 cumulative cases in Central Africa (Map 1).

The virus is already significantly present in 11 Central African Countries where the first cases had been progressively reported since February 2020 (Map 1, Map 2, Figure 2 and Table 1).

Figure 1. Map 1.

Figure 2. Map 2.

Figure 3. The weekly evolution of the number of cumulative confirmed cases and deaths in the Central African sub-region (Updated May 31, 2020).

Table 1. Distribution of the number of cases and deaths of COVID-19 in Central African States (Updated May 31, 2020)

Table 2. Demographic characteristics of Central African States

Demographic and health vulnerability

The age pyramid of sub-Saharan African Countries is known for its parasol shape, characterized by high birth and mortality rates. ^{Reference Chevallier and Le Golf25} Table 2 shows that the average age of the populations of the Central African sub-region is 17.81 years, with a minimum of 16 years in Chad, and a maximum of 20.7 years in the Congo, versus 43.1, 37, and 36.7 in Europe, Central Europe, and China respectively. In 2018, the proportion of people aged 65 years and above varied from 2 to 4% versus 18%, 16%, and 11% in Central Europe, North America, and China respectively. These demographic data show sub-Saharan African populations to be younger. The effect of age structure on COVID-19 lethality has been underlined in worldwide, European, Asian, and North American COVID-19 statistics. It was therefore observed that the lethality of COVID-19 was much higher in elderly people than in other age groups. In Italy, for example, 84.6% of deaths due to COVID-19 were made up of people aged 70 and over, 10.9% aged between 60 to 69, 4.2% from 40 to 49, 0.3% from 30 at 39, and 0% under 30. ^{Reference Mahase26,27} According to those demographic and COVID-19 statistics, the age structure of the population could be linked to the low lethality rate and the high number of recoveries observed in the Central African sub-region.

The gender-related vulnerability to COVID-19 should be well studied in the African context. UN Women underlined that paying attention to the needs and leadership of women could strengthen the response to COVID-19. ²⁸ The evidence from China suggests that the number of men who died from COVID-19 is 2.4 times higher than that of women (70.3 vs. 29.7%, P = 0.016). ^{Reference Jin, Bai and He29} Several births have been reported in central African countries among women infected with COVID-19, but no evidence has been published providing details. The African literature on the transmission of COVID-19 from mother to child, obstetric prevention, clinical presentation in the newborn, management, and prognosis must be strengthened for a better response in these vulnerable groups. Chinese studies showed that pregnancy and childbirth did not aggravate the course of symptoms or CT-scan features of COVID-19 pneumonia. ^{Reference Liu, Li and Wu30} According to the CDC, the transmission of SARS-CoV-2 to neonates could occur during the postnatal period when neonates are exposed to mothers, visitors, or healthcare personnel with COVID-19. There is poor evidence about possible intrapartum, peripartum, or vertical transmission. Even though information on clinical presentation and disease severity among neonates is limited, data from case reports and small case series suggest that infants may be at higher risk for severe illness from COVID-19 compared to older children. ³¹

Our results showed that the gross mortality is 8.6 per 1000 inhabitants in Central African sub-region, with extremes of 5 to 13 per 1000 inhabitants, depending on the country. Life expectancy in this sub-region is 61.09 years, with a minimum of 52 years in Central African Republic (CAR) and a maximum of 70 years in São Tomé and Príncipe versus 77 years in Central Europe, 79 years in North America, and 77 in China (Table 3). These large differences are connected to the high mortality and morbidity of other diseases in the Central African sub-region (Table 5). Indeed, observations made in developed countries have revealed greater lethality of COVID-19 in people with certain co-morbidities. ^{Reference Phua, Weng and Ling32} According to the WHO data, the HIV prevalence of the Central African sub-region is 2.6%, with a minimum of 0.7 in São Tomé and Príncipe and a maximum of 7.1 in Equatorial Guinea. The prevalence of diabetes is 5.4% in Central African sub-region, with a minimum of 2.4 in São Tomé and Príncipe and a maximum of 6 in Central African Republic, Democratic Republic of the Congo, Congo, Chad, Equatorial Guinea, Gabon, and Cameroon. A total of 239469 cases of cancers were reported in the Central African sub-region in 2020 (Table 3). In addition, the endemic malaria, malnutrition, poverty, and underdevelopment constitute a vicious circle, ^{Reference Fillol, Cournil and Cames33} with characteristics of slow-onset disasters to which are added the current problem. All these diseases are likely to weaken the health situation of the populations of the Central African sub-region and contribute to greater lethality of COVID-19.

Table 3. Morbidity and mortality indicators of Central African States

The high gross mortality observed in the Central African sub-region is also favored by the low epidemic-response capacity of the health infrastructure and human resources. Indeed, our results show that the number of hospital beds per 1000 inhabitants in the Central African sub-region is 1.7 with a minimum of 0.4 in Chad and a maximum of 6.3 in Gabon (Table 4) versus 6.4, 2.9, and 4.2 in Central Europe, North America, and China respectively. The number of doctors per 1000 inhabitants is 0.2 with a minimum of 0.04 in Chad and a maximum 0.4 in Gabon and Equatorial Guinea (Table 4) versus 3.1, 2.6, and 2.0 in Central Europe, North America, and China respectively. The number of nurses and midwives per 1000 inhabitants is 1.1 with a minimum of 0.4 in Chad and a maximum of 2.6 in Gabon and Equatorial Guinea (Table 4) versus 7.2, 14.1, and 2.7 in Central Europe, North America, and China. ⁷ It has been observed in Italy that 12% of COVID-19 patients received before March 12, 2020 required intensive care. Many developed countries like Italy and France which are renowned for their state-of-the-art health infrastructure and human resources were overwhelmed by the enormous influx of COVID-19 patients. ^{Reference Phua, Weng and Ling32} This comparative analysis gives an idea of the need for Central African countries to urgently improve their intensive care services for a better response to this health crisis. Thus, additional studies must be carried out to assess the intensive care infrastructure quantitatively and qualitatively in Central African countries.

Table 4. Some health care indicators

Elsewhere, we found that there were some countries like Burundi and Angola which have to date performed a very low number of COVID-19 tests per 1 million inhabitants, 24 and 305 respectively (Table 1). Furthermore, as highlighted by the WHO, the sub-Saharan region seems to have the lowest rate of COVID-19 testing. This is the cause of the fear of a possible ‘silent epidemic’ in this region if its leaders do not prioritize coronavirus testing. According to the WHO, during the Ebola outbreak in West Africa from 2014 to 2016, apart from the 11000 reported deaths due to Ebola infection, another 10000 people died from common diseases. ¹⁷ This means that the management of other usual pathologies remains a significant public health burden during this pandemic. This may weaken the national and sub-regional responses during this health crisis due to the COVID-19 pandemic and vice-versa. It is therefore evident that the absence of universal health coverage in all the countries of Central African sub-region except for Gabon could have a negative impact on gross mortality in this period. ³⁴ Obviously, the existence of another ongoing outbreak could further increase vulnerability to the COVID-19 pandemic. This is the case of the Democratic Republic of the Congo, which is going through its 9th Ebola epidemic since August 2018, in the provinces of Ituri and North Kivu. The WHO declared it a public health emergency of international scope in July 2019. ¹⁷ The last cases of this outbreak were reported on April 16, 2020 and resulted in 3458 confirmed cases and 2277 deaths. ³⁵ It can also be hoped that the experience of these communities that faced a previous major outbreak can contribute to improved resilience to future outbreaks. In the same way, the Congo and Gabon have also each encountered 4 Ebola outbreaks between 1994 and 2005. ^{Reference Berliner36} As described in Table 4, most Central African Countries have experienced Cholera outbreaks. ^{Reference Ali, Nelson and Lopez37} However, each of these countries has encountered at least 1 other deadly outbreak such as yellow fever, measles, necrotizing fasciitis, Marburg virus, Meningitis. ^38–43 An intergovernmental collaboration framework at the sub-regional level could be a means for sharing such epidemiological experiences for better capacity-building.

Social, financial, and economic vulnerability

According to Table 3, the Gross Domestic Product (GDP) in the Central African sub-region is 23.43 billion USD with a minimum of 2.54 billion USD in Central Africa Republic and a maximum of 95.34 billion USD in Angola. Given that the West Africa Ebola outbreak weakened the economies of Liberia, Sierra Leone, and Guinea, ⁴⁴ this should be enough reason to anticipate an economic crisis during this COVID-19 pandemic and its recovery phase. It appears that, apart from Gabon and Congo, 9 of the 11 countries in the Central African sub-region are among the bottom 50 in the World Bank Poverty Ranking according to the Human Development Index. Furthermore, 45.49% of the population of the Central African sub-region live with less than 1.9 USD/day with a minimum of 3.4% USD in Gabon and a maximum of 76.8% in Equatorial Guinea. The unemployment rate is 6.53% with a minimum of 1% in Rwanda and a maximum of 20% in Gabon. Additionally, 80.8% of the populations of Central African sub-region rely on the informal non-agricultural sector for survival, with a maximum of 96% in Democratic Republic of the Congo (Table 5). Accordingly, certain response strategies like confinement, quarantine, and rapid strengthening of the health infrastructures, which have proven very effective against COVID-19 in China would be difficult to implement in most of these countries if there is no substantial financial support put in place. ^{Reference Zunyou and Jennifer45} Some of the countries in this sub-region have recently started de-confinement and the reopening of borders, schools and bars despite the significant and continuous increase in the number of cases and deaths.

Table 5. Socio-economic characteristics of the Central African states

GDP, Gross Domestic Product; HDI, Human Development Index.

The adult literacy rate is 70% in the Central African sub-region, with a minimum of 22% in Chad and a maximum of 94% in Equatorial Guinea (Table 5). The Ebola epidemic in West Africa has demonstrated the value of community engagement in the response to outbreaks. ^{Reference Mamadou Mbaye, Kone and Kâ46} It is obvious that in the current situation of the COVID-19 pandemic, a low literacy rate in a country, associated with misinformation and belief in conspiracy theories, can have a significant impact on the involvement of communities in the response. This was in fact 1 of the factors behind the persistence of community transmission of Ebola virus infection in West Africa from 2014 to 2016. ^{Reference Waldispuehl47} Raising awareness and implementing proper communication are crucial parameters to take into consideration during this pandemic.

Conflicts are known for their ability to weaken a country’s institutions and economy, and the Central African Sub-region is not an exception. ^{Reference Jean-Paul, Jean-Claude and Stéphane48,Reference Hugon49} This sub-region has experienced several armed conflicts in recent decades. The Democratic Republic of the Congo has been plagued by repeated wars for several decades. This country has been confronted since 2004 by the conflict in North Kivu, which has been compounded by an Ebola outbreak in the same area. For the last 3 years, Cameroon has been facing an internal conflict in its 2 Anglophone regions, and in the far North, for more than 10 years Chad has been involved in the war against the Boko Haram. Central African Republic (CAR) is still recovering from its civil war, which lasted between 2013 and 2017. Furthermore, many countries in this region are faced with corruption and embezzlement of public funds that could sabotage the sustainable and effective implementation of a resilience strategy to this health crisis. ⁵⁰ The overcrowding noted in most prisons and detention centers in Central African countries can make them epicenters of COVID-19 if strategies of decongestion and barrier measures are not implemented. ⁵¹