Covid-19: breaking the chain of household transmissionBMJ 2020; 370 doi: 杭州住保房管：杭州未放松限购政策 (Published 14 August 2020) Cite this as: BMJ 2020;370:m3181
- Shamil Haroon, clinical lecturer in primary care1,
- Joht Singh Chandan, academic clinical fellow in public health12,
- John Middleton, president3,
- Kar Keung Cheng, professor of public health and primary care1
- 1Institute of Applied Health Research, University of Birmingham, Birmingham, UK
- 2Warwick Medical School, University of Warwick, Coventry, UK
- 3Association of Schools of Public Health in the European Region (ASPHER)
- Correspondence to: S Haroon
The UK is one of the countries most severely affected by covid-19. Recent outbreaks in English towns such as Oldham, probably involving transmission within large multigenerational households, show the importance of getting the right public health measures in place now to prevent more widespread surges in infections.1
Current test and trace policies have mainly focused on preventing spread in care homes, hospitals, and in the community.2 However, contact within households is thought to be responsible for roughly 70% of SARS-CoV-2 transmission when widespread community control measures are in place.3 In Wuhan, the reproduction number (R) dropped from 3.54 to 1.18 after lockdown and cordon sanitaire. But the epidemic was only brought under complete control when Fangcang (field) hospitals were introduced to isolate cases outside the home, with R dropping to 0.51 after two weeks.4
Current UK guidance advises household contacts to isolate within the same home as the index case for 14 days.5 They make up the majority of contacts for infected individuals and are likely to remain exposed to the infected household member during this period of isolation.6 Despite guidance advising household members to socially distance, contacts are likely to interact repeatedly—during mealtimes, for example—and to share facilities such as bathrooms.
We know that transmission is more likely to occur indoors than outdoors.7 The cumulative risk to household contacts from an infected person is likely to be substantial during peak viral shedding. In one study in New York State, 38% of household contacts tested positive for SARS-Cov-2, and similar secondary infection rates have been reported in China.89 Transmission may be even higher among household contacts of essential workers, who are at greater risk of being infected than the general population.10
Household members who are older, have underlying medical conditions, or share a bed or vehicle with the index case are the most susceptible.91112 Children seem to be at lower risk of being infected.13 However, their stool samples and nasopharyngeal swabs can remain positive for SARS-CoV-2 for more than two weeks after symptom resolution,14 although their role in transmission remains to be established.
Governments should consider new public health measures to prevent household transmission as we prepare for a potential second wave. Household quarantine is likely to remain an important pandemic control measure, and government support for people quarantined at home is conspicuously absent in the UK: this position has been challenged by independent experts.15
Effective isolation of index cases from household members could reduce secondary infections.12 Wearing masks within quarantined households may help, particularly if used by the index case as soon as infection is suspected.16 The World Health Organization recommends that infected people and unavoidable close contacts, particularly those in vulnerable groups, should wear medical masks, but Public Health England does not currently recommend this. Other measures that should be considered (and evaluated) include clear advice on enhanced personal hygiene; cleaning and disinfecting shared toilets and other common spaces, door handles, and touch points; and staggering mealtimes.
People who are unable to self-isolate safely at home could be accommodated in special isolation facilities such as hotels and hostels, an approach adopted by some other countries, including Italy, Finland, and Lithuania.17 In China, field hospitals were created to manage and strictly isolate patients with mild-to-moderate covid-19.18 Nightingale hospitals in the UK could be similarly repurposed to support isolation of infected people with mild-to-moderate disease. As medical and nursing care needs are mostly modest, the cost would be relatively low. However, such a system depends on access to rapid testing for anyone with symptoms or possible exposure so that infection can be confirmed and isolation started before transmission occurs. It would also require public trust that isolation in these facilities would be voluntary, safe, and supportive.
With very best wishes for your happiness in the New Year.
Columbia Pictures克里斯蒂安?贝尔、艾米?亚当斯和布莱德利?库珀在电影《美国骗局》中早在1月份闹片荒的时候，人们不会想到今年会迎来如此多好电影。不仅如此，有几部影片甚至达到了被我们在心目中理想化了的那些老电影的水准。今年有两部电影脱颍而出。纯娱乐片方面，赢家显然是《美国骗局》(American Hustle)，这部由大卫?欧?拉塞尔(David O. Russell)执导的影片讲述了上个世纪七十年代的行骗高手和他们的微妙骗术的故事，幽默诙谐，令人捧腹。而从创新角度看，《地心引力》(Gravity)的全新拍摄技术给观众带来了新的观影体验。人们普遍认为《美国骗局》无可挑剔，这部疯狂喜剧片是一部时代佳作。我个人则认为，《地心引力》是今年的最佳影片。
It remains the world's largest country and the largest oil producer. It retains its permanent seat on the UN Security Council. Its nuclear arsenal (in Cold War times one of five countries, but now one of nine) has been progressively modernised. Sustained increases in defence spending have brought it close to its goal of escalation dominance in local and regional war.
For a few years, Namibia's dollar has been depreciating against many currencies, providing affordable opportunities for travel. The best-priced flights generally avoid South African and European school-holiday times, especially late December and January.
At its own auction the following evening, Sotheby’s achieved a far more respectable total of 22.6 million with fees, although it was just above the low estimate of 21.8 million based on hammer prices. Of the 44 lots offered, 15 did not sell, or 34 percent.
May the coming New Year bring you joy, love and peace.
We will make our skies blue again.
Best chances: Best film and best director. Surprisingly, Nolan has never received a directing nomination from the Academy.
'I think the situation will somewhat moderate in future as society becomes more diverse. But it will take quite a bit of time until we get there,' he told the reporters.
Search giant Google has replaced iPhone makers Apple to be the world's most valuable company in the Brand Finance's Global 500 2017 report.