China's best case scenario for an Ebola outbreak: 3000 deaths

by Michael Woodhead

With more than 600,000 annual passenger arrivals from Africa and a poor to non-existent public health infrastructure in most parts of the country, China faces  a very real risk of an Ebola outbreak. That the verdict of infectious disease specialists who have modelled what will happen if a person with Ebola lands in China and is not detected immediately.

Dr Chen Tianmu and colleagues from the Changsha Center for Disease Control and Prevention have used data from previous Ebola outbreaks overseas and also from outbreaks of dengue and HIV viruses in China to model the likely spread of the infection before it can be brought under control. They modelled several different scenarios based on different levels of infectivity of the virus and different levels of detection and containment.

They based their calculation on the fact that there were 524,900 African visitors and 112,966 Chinese returning from Africa each year in China. Based on current distribution of Ebola Virus Disease and the rates of carriage in Africa, they estimated that 0.04%–0.16% of these arriving passengers in China (255–1021 people) may carry Ebola. Even if an optimistic assumption is made that only 1% of them slip through the entry-exit inspection and only 1% of these are not picked up by further reporting and monitoring follow ups, this would still mean 3-10 Ebola virus carriers could be at large in China.

The researchers noted that China lacks a primary care system and most sick patients go direct to hospitals that are overcrowded and where Ebola patients might spread the virus to others. China also has limited public health reporting and surveillance systems for much of the country, and it would therefor be possible that cases of Ebola virus could be misdiagnosed and slip though the net until the patient became symptomatic and infectious.

The researchers then calculated that the likely impact of such 'index cases' spreading the Ebola infection to others would be outbreaks of Ebola in China affecting between 6000-10,000 people. With a likely fatality rate of around 50% this would mean a severe mortality burden for China, they wrote.

Writing in Travel Medicine and Infectious Diseases, they said the lack of Ebola testing facilities in China and poor infection control practices would further encourage the spread of the infection, they predicted. Other factors, such as the lack of quality control on blood transfusions (as seen with outbreaks of HIV and hepatitis) would also increase the risk of spreading Ebola in China, they warned.

"Even if a good surveillance and monitoring system is implemented at immigration, an effective and efficient local medical response system involving primary health care providers and awareness of the general public is necessary to minimise the risk of an Ebola Virus outbreak due to other unknown sources," they suggested.

China's answer to Ebola: a lethal haemorrhagic fever that kills 20,000 people a year

by Michael Woodhead

Like many other countries, China has gone into a hysterical spin about the threat posed by Ebola virus disease.

Authorities have dusted off the useless thermal scanners last used in the avian flu outbreaks, and have started screening passengers arriving at from Africa at Chinese airports. And despite the World Health Organization saying that China does not need to be overly concerned about the disease, authorities have been issuing stern warnings to health workers about being vigilant for Ebola and also looking with suspicion on the African expats living in cities such as Guangzhou. The irony is that China has seen its own counterpart of Ebola virus disease, a killer disease that has been increasing dramatically in the last two years.

But first some background: Ebola is a haemorrhagic fever, caused by the Ebola virus, which belongs to the  Filoviridae family of RNA viruses. The virus comes from apes and bats and is only transmitted between humans by body fluids such as blood and saliva - in Africa it has been spread by hunters cutting up meat from infected animals, and spread to healthcare workers and close relatives to touch the dead bodies of Ebola victims at traditional African funerals. In the latest outbreak there have been 1323 confirmed and suspected cases of Ebola reported, and 729 deaths. That's a mortality rate of 55% according to my calculator.

What to make then of China's recent little remarked but lethal cases of haemorrhagic fever? In April, Dr Du Hong and colleagues from the Center for Infectious Diseases, Tangdu Hospital, Xian, described the horrific symptoms of some of the 356 patients who had been treated at their hospital for  "hemorrhagic fever with renal syndrome" (HFRS),  a disease caused by Hantavirus that is spread by rats (or more specifically in their droppings, which may become aerosolised and spread to anyone working near where rats have been active).

The symptoms are similar to Ebola: fever, circulatory collapse with hypotension, hemorrhage, but also with acute kidney failure (hence the name renal syndrome). The difference between Ebola and HFRS is that the Hantavirus disease has a death rate of 'only' 40%. For China, which has had about 50,000 cases of HFRS annually, that means about there have been, at a conservative estimate, 20,000 deaths from Hanta virus every year. Makes the 730 Ebola deaths in Africa look fairly insignificant doesn't it? And as with Ebola, there is no treatment or vaccine for Hantavirus, only supportive care.

And that's not all. China has other types of haemorrhagic fever. This month The Lancet carries a report of the emergence of one, known as "severe haemorrhagic fever with thrombocytopenia". This is a viral disease spread by ticks, caused by the SFTS phlebovirus in the Bunyaviridae family. According to Dr Liu Quan and colleagues from the State Key Laboratory of Veterinary Etiological Biology, Lanzhou, SFTS was first reported in 2010 and has since been found in 11 provinces of China, with about 2500 reported cases, and an average case-fatality rate of 7%. That's about 175 deaths. As the study authors say with some understatement: "The disease has become a substantial risk to public health".

China is the epicentre for Hantavirus haemorrhagic fever in the world, but it is not the only country affected. The disease is also seen in Europe and the US - a Denver man died of the infection just this week. But with tens of thousands of Chinese people dying every year from this terrible haemorrhagic disease, perhaps China ought to worry more about curbing Hantavirus - and the rats that carry it - rather than panicking over the threat from an African outbreak of Ebola.

Lancet profile of Dr Lixin Jiang: at the heart of China's evidence base

Dr Jiang Lixing

by David Holmes
There's a quiet revolution going on in China, and Lixin Jiang is at the very heart of it. 
Since the turn of the millennium, Jiang has been in the vanguard of a growing movement within the Chinese medical profession to make evidence-based medicine the foundation of their practice, and to build the evidence base from within China itself. And with the support of Shengshou Hu, the influential head of Fuwai Hospital in Beijing, where Jiang is based at the affiliated National Centre for Cardiovascular Disease, she has been a “whirlwind force for evidence” says Richard Peto, Co-Director of Oxford University's Clinical Trial Service Unit (CTSU).
Since 1999, Jiang has worked closely with Peto and his fellow CTSU Co-Director Rory Collins on a succession of large, international trials, and she credits the pair with opening an “entirely new window, through which I not only learned how to manage large-scale clinical trials in China, but more importantly, learned how to look at the world with critical eyes”. This though, according to Peto, is Jiang being too modest. “She was really excited by the idea of clinical trials and we just introduced her to the concept. She picked up the ideas and ran with actually making them work, and trying to actually get them accepted within the Chinese medical profession.”
Jiang's first large-scale trial, COMMIT, was a baptism of fire, with over 45 000 patients with acute myocardial infarction enrolled from 1250 hospitals. With guidance from CTSU, Jiang began to oversee the routine running of the trial in China in 1999, and during the next few years she took her team to monitor more than 400 hospitals throughout China, including many smaller, secondary hospitals in remote rural areas. As well as providing a crash course in the vagaries of clinical trial management, the study affected Jiang on a personal level. “I was born in the city and I didn't have a real picture of rural life; before that study I lived in a very limited, narrow world”, she says. “But when I visited these hospitals I was so touched by the real situation; so much poverty, it was so difficult for doctors and patients in rural areas at that time. And through visiting these kinds of hospitals all around China, it touched me so deeply, and I learned about China, I learned more about hospitals, and I learned about clinical trials.”
COMMIT was a watershed moment not just for Jiang, but for clinical research as a whole in China. “The Chinese doctors were really excited to have good evidence, Chinese evidence, about the treatment of Chinese patients in Chinese hospitals”, says Peto. After visiting a number of trial sites, the US Food and Drug Administration approved a new indication for clopidogrel in acute myocardial infarction: the first time such a decision had been based on data solely from China. The “research got taken worldwide and influenced worldwide treatment patterns”, says Peto. “Without her it wouldn't have succeeded”. An auspicious precedent thus set, Jiang has gone on to coordinate a succession of large, long-term, international clinical trials and case-control studies in China, including HPS2-THRIVE, TRACER, and HPS3/TIMI55:REVEAL, INTER-HEART, and SHARP.
The success of these studies owes a huge debt to Jiang and her team's meticulous planning and tireless capacity building, according to Runlin Gao, Chief Cardiologist of Fuwai Hospital and the immediate Past President of the Chinese Society of Cardiology. “She established a committed research team and a stable collaborative network, including nearly 200 large hospitals in China, and she and her team also developed some practical modules for running trials in China, such as the pre-registration of potential participants, a process of identifying capable and committed local sites, and central monitoring”, Gao explains.
But for all the progress that has been made, Jiang is a realist. “Sometimes I say that maybe our limitations are much bigger than our strengths”, she comments, pointing to the complexity of the regulatory system in China. The process to get a trial approved “generally takes about 10 months to 1 year”, explains Jiang; “that is longer than most other western countries, and the process is not very easy”. The unfamiliarity of patients with large-scale clinical research in China can also present problems. “Patients do not fully understand this type of study, they very often have doubts about our motivation, and we don't have a very harmonious relationship between doctors and patients here, and that is a very big problem”, says Jiang.
“Overall”, Jiang says, “the government has greatly improved the conditions for clinical research, but we still have a long march to go. We in China really need evidence not only for clinicians but also for policy making, so China should accelerate the pace of improvement.” As Principal Investigator of China-PEACE, a major cardiovascular outcomes study funded by the Chinese Government that involves more than 200 hospitals across China, Jiang will play a pivotal part in generating this knowledge “for China from within China”, says Gao. And as Honorary Editor of The Lancet Chinese Edition, Jiang says she hopes to “accelerate the dissemination of knowledge, and the concept of evidence-based medicine” in China. According to Peto, she will succeed. “She's making things happen that I don't think anyone else would be able to make happen”, he says. “She's really the trialist to watch.”
Read more: The Lancet

China's hot and cold weather increases coronary deaths

Extremely cold and hot temperatures in China's cites increase the rate of deaths from ischaemic heart disease, a study has shown. Researchers from Beijing University examined the effects of extremely cold and hot temperatures on ischaemic heart disease mortality in five cities: Beijing, Tianjin, Shanghai, Wuhan and Guangzhou. After analysing 16,600 deaths they found that relationships between temperature and IHD mortality were different in all five cities.  The threshold for cold-related coronary deaths was lower in northern cities than in southern cities. In Beijing, Tianjin and Guangzhou, the effects of extremely cold temperatures were delayed, while Shanghai and Wuhan had immediate cold effects. The effects of extremely hot temperatures on coronary  deaths were seen immediately in all the cities except Wuhan. Overall, coronary mortality increased by almost 50% in extremely cold temperatures compared with the 1milder temperatures, while coronary mortality increased 18% with extremely hot temperatures compared with normal temperatures.
"Our results are consistent with the hypothesis that people in the north are more susceptible to the effects of hot temperatures and in the south to the effects of cold temperatures," conclude study authors Dr Guo Yuming and Professor Pan Xiaochuan.


Read more: Heart Journal