立即打开
为什么非洲的新冠肺炎死亡病例这么少?这是一个谜!

为什么非洲的新冠肺炎死亡病例这么少?这是一个谜!

Amiah Taylor 2022-03-28
从整体上来说,新冠肺炎疫情给非洲带来的影响相对较小。

尽管悲观主义者预测新型冠状病毒将让非洲大陆陷入瘫痪,但似乎在更富裕、医疗设备更完善的国家,其死亡人数更多。从整体上来说,新冠肺炎疫情给非洲带来的影响相对较小。

来自Statista的数据显示,自2020年首次出现新冠肺炎死亡病例以来,截至今年3月13日,欧洲死于新冠肺炎的人数已经高达1883711人,具体到法国,有140600人死于新冠肺炎。世界银行(World Bank)的数据表明,截至2018年,法国每10000人中有6.5名医生,而截至2019年,塞拉利昂每10000人中仅有1.4名医生、护士和助产士。相比于塞拉利昂这样的非洲国家,法国的医疗专业人员数量是其数量的四倍多,但实际情况是:法国死于新冠肺炎的人数比塞拉利昂高出99%以上。据路透社(Reuters)报道,塞拉利昂仅报告了125例与冠状病毒相关的死亡病例。

据《纽约时报》(New York Times)报道,自新冠肺炎疫情开始以来,在塞拉利昂的卡马奎,其新冠肺炎应急中心仅记录了11例病例,没有死亡病例。

而且,不仅仅是在塞拉利昂。据路透社报道,自新冠肺炎疫情开始以来,加纳共报告了1445例死亡病例。非洲一些国家报告的与冠状病毒相关的死亡病例人数甚至没有达到四位数,例如坦桑尼亚自新冠肺炎疫情开始以来报告了800例与新冠肺炎相关的死亡病例,多哥报告了272例与冠状病毒相关的死亡病例。有一点可以肯定的是,非洲各个国家的新冠肺炎死亡率如此之低并不是因为当地人疫苗接种的覆盖率高。在乌干达、赞比亚等许多非洲国家,疫苗分配不平等现象持续存在。比如,利比里亚已经接种了约120万剂新冠疫苗,这相当于该国约有12.2%的人接种了疫苗,但该国报告的新冠肺炎死亡病例人数仅为294例。另一方面,据报道称,在像葡萄牙这样的欧洲国家,其民众已经接种了超过2200万剂次新冠疫苗,接种率超过92%,但该国报告的新冠肺炎死亡病例人数却仍然有21342例。

两相对比,这种差异十分明显,于是许多人都想知道:为什么新冠肺炎疫情在非洲国家的影响更小?

难道是因为非洲的新冠肺炎死亡病例没有被记录在案?

世界银行等搜集数据资料的机构纷纷怀疑信息来源的可靠性,毕竟新型冠状病毒的检测比较稀缺且大多数新冠肺炎患者无法就医导致最后在家中死亡,所以说非洲的新冠肺炎死亡率被严重低估了。根据SARS-CoV-2专家、约翰斯·霍普金斯大学(Johns Hopkins University)分子微生物学和免疫学系(Molecular Microbiology & Immunology Department)的副主任安迪·佩科斯博士的说法,尽管在某些非洲国家,例如肯尼亚和津巴布韦,可能在充分检测新型冠状病毒方面存在问题,但缺乏病例记录可能不是导致报告的新冠肺炎病例数量较少的主要原因。

佩科斯告诉《财富》杂志:“我认为很明显的是,SARS-CoV-2已经多次进入非洲国家,但在某些情况下,它并没有导致像我们在其他地方看到的那样规模性爆发,包括像南美洲这样与非洲部分地区位于同一经线上的地方。”

佩科斯更相信:“非洲国家对传染病所作的监测也很足够,因为他们能够发现新冠肺炎导致的严重病例和死亡病例。”所以说,在非洲国家,死于冠状病毒感染的患者人数较少的现象可能是由于其他原因。

如果非洲国家没有少报新冠肺炎死亡病例,那么这种差异是怎么造成的?

一些科学家和研究人员认为,由于“交叉反应性抗体”的存在,像塞拉利昂这样长期暴露于埃博拉病毒和拉沙热病毒的非洲公民具有更高的复原率。根据同行评审和开放获取的病毒学杂志《Viruses》,比如,2021年的一项研究显示,塞拉利昂的埃博拉和拉沙热幸存者的血液样本对季节性冠状病毒的抗体高于美国献血者,从而产生了交叉保护性免疫。

佩科斯了解交叉保护性免疫的论点,但他认为这一论点缺乏证据难以让人信服。

佩科斯告诉《财富》杂志:“关于为什么我们在一些非洲国家没有看到大量的新冠肺炎病例,有很多理论。我经常听到一种理论,说某种先前存在的免疫力会抑制SARS-CoV-2感染带来的影响,但我还没有看到任何强有力且令人信服的数据来支持这一理论。”

佩科斯认为,拉沙热和埃博拉病毒没有造成足够多的病例,所以说形成群体免疫力来对抗新型冠状病毒也就无从谈起,也就是说这与非洲的新冠肺炎病例数量少无关。他认为,疟疾的分布范围足够广泛,可以形成群体免疫力,但还没有找到疟疾与新冠肺炎病例数量较少之间的密切联系。

佩科斯告诉《财富》杂志:“此外,一些对非洲国家抗体水平的研究并未发现先前存在的SARS-CoV-2抗体的强烈信号,可能是与抗体无关的部分免疫反应起了作用——也许是T细胞反应等细胞免疫反应起了作用。”(财富中文网)

译者:ZHY

尽管悲观主义者预测新型冠状病毒将让非洲大陆陷入瘫痪,但似乎在更富裕、医疗设备更完善的国家,其死亡人数更多。从整体上来说,新冠肺炎疫情给非洲带来的影响相对较小。

来自Statista的数据显示,自2020年首次出现新冠肺炎死亡病例以来,截至今年3月13日,欧洲死于新冠肺炎的人数已经高达1883711人,具体到法国,有140600人死于新冠肺炎。世界银行(World Bank)的数据表明,截至2018年,法国每10000人中有6.5名医生,而截至2019年,塞拉利昂每10000人中仅有1.4名医生、护士和助产士。相比于塞拉利昂这样的非洲国家,法国的医疗专业人员数量是其数量的四倍多,但实际情况是:法国死于新冠肺炎的人数比塞拉利昂高出99%以上。据路透社(Reuters)报道,塞拉利昂仅报告了125例与冠状病毒相关的死亡病例。

据《纽约时报》(New York Times)报道,自新冠肺炎疫情开始以来,在塞拉利昂的卡马奎,其新冠肺炎应急中心仅记录了11例病例,没有死亡病例。

而且,不仅仅是在塞拉利昂。据路透社报道,自新冠肺炎疫情开始以来,加纳共报告了1445例死亡病例。非洲一些国家报告的与冠状病毒相关的死亡病例人数甚至没有达到四位数,例如坦桑尼亚自新冠肺炎疫情开始以来报告了800例与新冠肺炎相关的死亡病例,多哥报告了272例与冠状病毒相关的死亡病例。有一点可以肯定的是,非洲各个国家的新冠肺炎死亡率如此之低并不是因为当地人疫苗接种的覆盖率高。在乌干达、赞比亚等许多非洲国家,疫苗分配不平等现象持续存在。比如,利比里亚已经接种了约120万剂新冠疫苗,这相当于该国约有12.2%的人接种了疫苗,但该国报告的新冠肺炎死亡病例人数仅为294例。另一方面,据报道称,在像葡萄牙这样的欧洲国家,其民众已经接种了超过2200万剂次新冠疫苗,接种率超过92%,但该国报告的新冠肺炎死亡病例人数却仍然有21342例。

两相对比,这种差异十分明显,于是许多人都想知道:为什么新冠肺炎疫情在非洲国家的影响更小?

难道是因为非洲的新冠肺炎死亡病例没有被记录在案?

世界银行等搜集数据资料的机构纷纷怀疑信息来源的可靠性,毕竟新型冠状病毒的检测比较稀缺且大多数新冠肺炎患者无法就医导致最后在家中死亡,所以说非洲的新冠肺炎死亡率被严重低估了。根据SARS-CoV-2专家、约翰斯·霍普金斯大学(Johns Hopkins University)分子微生物学和免疫学系(Molecular Microbiology & Immunology Department)的副主任安迪·佩科斯博士的说法,尽管在某些非洲国家,例如肯尼亚和津巴布韦,可能在充分检测新型冠状病毒方面存在问题,但缺乏病例记录可能不是导致报告的新冠肺炎病例数量较少的主要原因。

佩科斯告诉《财富》杂志:“我认为很明显的是,SARS-CoV-2已经多次进入非洲国家,但在某些情况下,它并没有导致像我们在其他地方看到的那样规模性爆发,包括像南美洲这样与非洲部分地区位于同一经线上的地方。”

佩科斯更相信:“非洲国家对传染病所作的监测也很足够,因为他们能够发现新冠肺炎导致的严重病例和死亡病例。”所以说,在非洲国家,死于冠状病毒感染的患者人数较少的现象可能是由于其他原因。

如果非洲国家没有少报新冠肺炎死亡病例,那么这种差异是怎么造成的

一些科学家和研究人员认为,由于“交叉反应性抗体”的存在,像塞拉利昂这样长期暴露于埃博拉病毒和拉沙热病毒的非洲公民具有更高的复原率。根据同行评审和开放获取的病毒学杂志《Viruses》,比如,2021年的一项研究显示,塞拉利昂的埃博拉和拉沙热幸存者的血液样本对季节性冠状病毒的抗体高于美国献血者,从而产生了交叉保护性免疫。

佩科斯了解交叉保护性免疫的论点,但他认为这一论点缺乏证据难以让人信服。

佩科斯告诉《财富》杂志:“关于为什么我们在一些非洲国家没有看到大量的新冠肺炎病例,有很多理论。我经常听到一种理论,说某种先前存在的免疫力会抑制SARS-CoV-2感染带来的影响,但我还没有看到任何强有力且令人信服的数据来支持这一理论。”

佩科斯认为,拉沙热和埃博拉病毒没有造成足够多的病例,所以说形成群体免疫力来对抗新型冠状病毒也就无从谈起,也就是说这与非洲的新冠肺炎病例数量少无关。他认为,疟疾的分布范围足够广泛,可以形成群体免疫力,但还没有找到疟疾与新冠肺炎病例数量较少之间的密切联系。

佩科斯告诉《财富》杂志:“此外,一些对非洲国家抗体水平的研究并未发现先前存在的SARS-CoV-2抗体的强烈信号,可能是与抗体无关的部分免疫反应起了作用——也许是T细胞反应等细胞免疫反应起了作用。”(财富中文网)

译者:ZHY

Despite pessimistic projections that the coronavirus would cripple the African continent, it seems that wealthier and more well-equipped countries have higher death tolls and that the effect of COVID in Africa was comparatively minimal.

Since the first recorded death in 2020, a whopping 1,883,711 people have died from COVID in Europe as of Mar. 13, according to Statista. In France specifically, 140,600 people have died from COVID, according to Statista. As of 2018 there were 6.5 doctors per 10,000 people in France, according to The World Bank. And even with over four times as many health professionals as an African country like Sierra Leone—there are 1.4 doctors, nurses and midwives per 10,000 people in the country as of 2019—over 99% more people died from the coronavirus in France than Sierra Leone. In Sierra Leone only 125 coronavirus-related deaths have been reported according to Reuters.

And in Kamakwie, Sierra Leone in particular, the district’s COVID response center has registered a mere 11 cases since the beginning of the pandemic and no deaths, as reported by The New York Times.

And it’s not just Sierra Leone that has a low death toll. Ghana has reported 1,445 deaths since the pandemic started, according to Reuters. Some countries in Africa are reporting coronavirus-related deaths that don’t even reach the four-figure mark, like Tanzania which has reported 800 COVID-related deaths since the start of the pandemic, and Togo which has reported 272 total coronavirus-related deaths. And one thing is for certain, the low COVID mortality rates in various African countries are not owed to incredibly widespread vaccine access. Vaccine inequity is an ongoing issue in many African countries like Uganda, Zambia, and more. Liberia, for example, has administered about 1.2 million doses of the COVID vaccine which would amount to about 12.2% of the country being vaccinated and yet has only reported 294 total coronavirus-related deaths. On the other hand, a European country like Portugal has administered over 22 million doses of the COVID vaccine and is reportedly over 92% vaccinated, but still has reported 21,342 total coronavirus-related deaths.

As a result of this inescapable discrepancy, many are wondering: how are African countries faring better than other parts of the world?

Are African COVID deaths just not being recorded?

Some sources like WorldBank have asserted suspicions that African COVID death rates are heavily underreported given the scarcity of COVID tests and the fact that most coronavirus-related deaths occur at home. While it’s worth acknowledging that there may be issues with adequate testing for COVID-19 in some African countries, like Kenya and Zimbabwe for example, a lack of case recording is likely not the culprit behind the fewer numbers of COVID-19 cases being reported, according to Dr. Andy Pekosz, a SARS-CoV-2 expert and the Vice Chair of the Molecular Microbiology & Immunology Department at Johns Hopkins University.

“I think it's quite clear that SARS-CoV-2 has been introduced into African countries on numerous occasions but in some cases, it's not lead to outbreaks that are anywhere close to the scale we have seen elsewhere, including places like South America that lie on the same longitudinal lines as parts of Africa,” Pekosz told Fortune.

Pekosz is more convinced that there is “certainly good enough monitoring of infectious diseases to have detected severe cases and deaths resulting from COVID-19,” and that the lack of coronavirus-related deaths in African countries is owed to something else.

If African COVID deaths aren't underreported, where is the discrepancy coming from?

Because of “cross-reactive antibodies,” some scientists and researchers think that African countries that were exposed to Ebola and Lassa fever, such as Sierra Leone, have citizens with higher rates of resilience. For example, in a 2021 study, the blood samples of survivors of Ebola and Lassa fever in Sierra Leone had higher antibodies to seasonal coronaviruses than American blood donors, resulting in cross-protective immunity, according to Viruses, a peer-reviewed, open access journal of virology.

Pekosz is aware of the cross-protective immunity argument but struggles to believe it wholeheartedly because of a lack of evidence.

“There are a lot of theories about why we don’t see lots of COVID-19 in some African countries. The theory that there is some preexisting immunity that is dampening the effects of SARS-CoV-2 infection is one I hear often, but I have not seen any strong convincing data to support this,” Pekosz told Fortune.

Pekosz believes that Lassa Fever and Ebola have not caused enough cases to generate immunity from COVID and therefore can’t be correlated to low case numbers in Africa. He believes that malaria has wide enough distribution to explain immunity, but has not been able to find a strong link to malaria and reduced COVID cases.

“Furthermore, some studies of antibody levels in African countries haven’t shown a strong signal of preexisting antibodies to SARS-CoV-2,” Pekosz told Fortune. “It may be that parts of the immune response not related to antibodies could be contributing–perhaps cellular immune responses like T cell responses.”

热读文章
热门视频
扫描二维码下载财富APP