Three experts from Oakland University William Beaumont School of Medicine 说“平坦曲线”是减缓当前冠状病毒爆发并最终恢复社会正常感的关键.

The insights were provided by 特蕾西泰勒, Ph.D., 基础医学学系微生物学副教授, assistant dean of 多样性 & 包容, OUWB, 德维恩Baxa，牛津大学基础医学研究系微生物学助理教授.

Taylor and Baxa — along with Matt Sims, M.D., 博蒙特健康中心传染病主任最近写了一本名为《十大菠菜台子》的书 & Infectious Diseases: Clinical Case Prep for USMLE.”

Also weighing in was Trini Matthew, M.D., associate professor, Department of Internal Medicine, OUWB, medical director of Hospital Epidemiology and Infection Control, Infectious Diseases & International Medicine, Beaumont Hospital, Royal Oak.

“平坦曲线”通常指的是需要减少每天的新病例数量，这样医院就不会不堪重负, according to Taylor. The “curve” is a bell-curve with the peak being the highest number of cases.

OUWB的专家们一致认为，使曲线变平的唯一方法是限制人与人之间的互动.

“基于显示其他国家(现在在美国)疫情接近对数轨迹的数据.S.)，在没有限制/取消(COVID-19在美国的传播)的情况下.S.), 毫无疑问，未来几周我们将面临极其严峻的公共卫生挑战,泰勒说. “By limiting gatherings, 我们可以开始降低病毒在我们社区中的传播速度:更少的社交互动意味着病毒传播给新人的机会更少.”

Like other organizations, Oakland University and OUWB have cancelled many events, such as the Match Day celebration, suspended in-person classes, among other things.

“迅速实施此类限制的地区和国家能够大幅减少新病例的增长，这并非巧合, thus saving many lives,泰勒说.

“意大利, on the other hand, 实施这些限制的速度很慢，现在每天有200人死于这种病毒.” 

Flattening the curve

越来越多关于如何减缓严重急性呼吸综合征冠状病毒2 (SARS-CoV-2)传播的新闻报道中，正在使用“使曲线变平”的想法。SARS-CoV-2是导致COVID-19疾病的病毒.

OUWB’s experts explained what “flattening the curve” means in this context.

Baxa说:“疫情有自然的上升期、高峰和衰减期. “这个周期形成了一个钟形曲线，y轴上的线是病例数. 高峰的高度是由感染引起的病例的最大数量，这个数字可能远远超过任何社会系统处理这一负荷的能力.”

Baxa说，流行病的数学模型可以帮助定义特定感染传播的特征. This is done through use of a value known as R₀ (pronounced “r-nought”).

R₀ 是否有一个值与因接触一个感染病例而被感染的平均人数有关.

For yearly influenza, it is estimated that R₀ is just over one, meaning about one person is infected from one contact case.

应该R₀ be above one, according to Baxa, the infection is expected to spread. For values less than one, an infection can be expected to fizzle out.

当前的R₀ of COVID-19 “is thought to be around three, 这意味着平均有三个人会被一次新的感染感染,Baxa说。.

But steps can be taken to lower the R₀.

“R₀ can be influenced by breaking the chain of transmission,” 马修说. “The goal is to get that R₀ 小于1，这样人们就不会被感染，这样我们就能控制疫情.”

Mathew said that means limiting face-to-face encounters, social distancing/staying a distance of at least 6 feet away from others, canceling events with large groups of people, frequent hand-washing.

Further complicating matters, 马修说, is the fact that people can be infected and not present any symptoms.

这就是为什么马修说，“当我们不知道谁可能会传播病毒时，我们需要继续努力限制面对面的互动，因为被感染的人可能没有全面发烧。, 发冷, or body aches that would otherwise make them stay at home.”

“如果人们被要求呆在家里，即使他们感觉很好——尽管他们可能被感染了——那么你就减少了病毒传播给其他人的机会, that’s very important,”她说。. 

结束在望?

Of course, everyone wants to know when things may start to return to normal.

Baxa说:“当每天发现的病例数量开始减少时，我们将知道大流行是自我限制的.”

“这只能通过监测和诊断测试数据来完成，”他说. “The more data we acquire, the more accurate our predictive models will become.”

The potential impact of warmer weather is yet to be determined.

“Coronavirus family members, of which SARS-CoV-2 is a member, 通常是周期性的，在一年中的某些季节的特定时间频率更高,Baxa说.

“现在就知道这种疫情是否会随着我们半球夏季的临近而减少还为时过早.”

泰勒说，她同意现在对病毒何时会减缓做出任何预测还为时过早.

“Because of the global pandemic status of this virus, plus the fact that it is a novel virus, it will be difficult to predict if/when the pandemic will slow down,”她说。. “希望我们目前为减轻这种病毒在全国和世界范围内的传播所做的努力将使我们的医疗保健和研究基础设施有时间开发有效的治疗方法来预防严重疾病.”

Note: Taylor and Baxa sourced date from the CDC and World Health Organization.