With West Africa’s Ebola epidemic passing the 1-year mark, two new reports yielded details about factors that fueled the event, including bats in a hollow tree that may have infected the index patient, a young Guinean child, and a silent chain of transmission that caused the disease to flare again in May after cases had sharply dropped off.
Also today, the World Health Organization (WHO) updated its Ebola numbers, saying there have been 20,129 cases, along with 7,879 deaths, in the three hardest-hit countries. The data include cases reported through Dec 28 in Guinea and Sierra Leone and through Dec 24 in Liberia. The totals reflect an increase of 48 cases and 37 deaths since the WHO’s update yesterday.
In addition, the WHO today posted a new timeline of the event, starting with its African regional office’s first report on the outbreak on Mar 23.
Bat colony suspected as virus source
The bat study, by a multidisciplinary group of German-led researchers, was conducted in April in the area around Meliandou, a village in a plantation region of Guinea where a 2-year-old boy thought to have been the index patient lived. The team published its findings today in an online edition of EMBO Molecular Medicine.
The 4-week investigation of the roots of zoonotic transmission where the outbreak began involved a field team that included anthropologists who looked at human exposure to bush meat and bats, ecologists who surveyed local wildlife, and veterinarians who analyzed samples from bats and other animals.
In other Ebola outbreaks, the virus was known to take a toll on larger animals, such as wild apes. However, the team found no evidence of population declines in the region’s wildlife populations. Also, children and women were among the first victims in the outbreak, rather than hunters, also suggesting that the virus probably didn’t jump from a larger animal.
Hunting and butchering fruit bats—a suspected Ebola reservoir—were common activities in southern Guinea, providing a link to humans. Also, the team found that children often hunt and grill insect-eating bats in and around villages, providing more exposure to the animals.
Though the group didn’t find any large colonies of bats in or near Meliandou, villagers showed them a large tree stump from a hollow tree near which the village children, including the index case, frequently played, catching and playing with bats. They said the tree burned on Mar 24, triggering a “rain of bats” that were collected to eat. However, the local people disposed of them after authorities the next day imposed a ban on consuming bush meat.
Genetic sequencing of the environment near the tree confirmed that small free-tail bats had been in the area, the same type the villagers described.
The team said the circumstances may have led to a massive exposure to bats, similar to events in bat-inhabited caves that have been implicated in the zoonotic transmission of Marburg virus. They added that their findings confirm the index case but suggest a slightly different transmission timeline, with the virus spreading to other parts of Guinea, then to Sierra Leone and other countries. Local people told the researchers that the boy died on Dec 28, several weeks later than the Dec 6 date reported in the medical literature.
Times piece describes missed opportunities
An undetected transmission chain was one of several missteps that led to the Ebola outbreak’s unprecedented size, according to an in-depth look at the events by a team of reporters from the New York Times. The report, based on a 2-month investigation, was first published yesterday.
The report describes how experts thought the outbreak was close to burning itself out, with sharply declining at the beginning of May, along with clues they may have missed that an unusual event was about to unfold, and missteps in the response.
Focusing on the time frame of the lull and the spike that followed, the team found that WHO and Guinean officials documented a handful of suspected cases across the border in Sierra Leone in March, but that information about two of the cases never got to senior health officials and investigators. This circumstance appears to have led to a chain of transmission that went unchecked for 2 months and didn’t surface until late May, when Sierra Leone confirmed its first Ebola case.
The report also says the same two cases that fell through the cracks sparked a second wave of illnesses in Liberia that began in late May.
Experts involved in the early response told the reporters that they didn’t deploy enough staff to the region and pulled them too soon. They also described management glitches by the WHO, which was stretched thin by budget cuts and other health and humanitarian crises.
Other factors that hobbled the response included some officials’ downplaying of the Ebola threat and public education campaigns that did more harm than good, such as early efforts that highlighted the lethality of the disease.
In tracing the first illnesses, including the boy who had the index case, investigators made faulty assumptions, and it took 12 weeks to determine that the illnesses and deaths were caused by Ebola, according to the report.
The WHO’s African regional office, initially appointed to lead the response, was suffering from sharp cuts in preparedness money and staff and was overmatched in its ability to handle the task, and it posed bureaucratic roadblocks in getting help from global experts, the article says.
In the first few months of the outbreak, lack of cross-border coordination hampered the response, and officials arriving from outside West Africa lacked a full understanding of the political and cultural challenges they would face, including deep distrust of government.
The Times team pointed out that Doctors without Borders declared the outbreak out of control on Jun 21, but the WHO didn’t declare a public health emergency of international concern until Aug 8.
Health officials who spoke with the Times said they wish they had devoted more staff and resources to the outbreak early on and had recognized how weak contact tracing was and the distinct culture of West Africa.
Pierre Rollin, MD, a top Ebola expert at the US Centers for Disease Control and Prevention, who was quoted extensively in the Times report, said some of the events couldn’t have been predicted, especially in the midst of an unfolding crisis. “There were a lot of things we didn’t know at that time. No one could have imagined that it would be what we have now,” he said.
From The New York Times, Friday, October 31st, 2014:
For six years, Mayra Martinez had been going to the same beautician in Queens, and considered her a friend. On Saturday, while getting her hair done, Ms. Martinez, 45, mentioned she had just gotten a new job.
“Where?” the beautician asked.
“Bellevue,” Ms. Martinez said.
“She just froze and asked, ‘Are you anywhere near him?’ ” Ms. Martinez recalled. Then the beautician asked her to please find someone else to do her hair.
By “him,” the beautician meant Dr. Craig Spencer, who is New York’s first Ebola patient. As Bellevue Hospital Center goes into its eighth day of treating Dr. Spencer, who had worked with Doctors Without Borders in Guinea, some of its employees are feeling stigmatized — a harsh consequence of being at the first hospital in the city to deal with an outbreak that has killed about 5,000 people in West Africa, and that is known to kill about half the people who become infected.
Bellevue’s medical director, Dr. Nate Link, said more than a dozen employees — not limited to those taking care of Dr. Spencer — had reported being discriminated against, including not being welcome at a business or social event. One employee lost a teaching position, he said.
Some nurses who moonlight at other jobs have been told they are not needed there, according to the New York State Nurses Association, a union. One nurse said her child was not allowed to go to day care. “These are obviously related to irrational fears in the community,” Dr. Link said.
On the subway to work early Tuesday, Ms. Martinez said, she overheard two passengers say they were horrified by Ebola and joke that it would soon turn people into zombies. Ms. Martinez, dressed in tan scrubs with her identification badge hung around her neck, tucked the badge inside her coat, “so they don’t retaliate against me.”
Medical workers who have treated Ebola patients at hospitals in Atlanta, Dallas and Omaha have also reported being stigmatized. The problem is severe enough that Mayor Bill de Blasio acknowledged it during a news conference at Bellevue on Sunday.
But sometimes the snubbing is taking place inside their own workplace. Nurses treating Dr. Spencer were in tears at a meeting this week as they complained about being shunned by other staff members in the elevators, one health care worker who was there said.
Workers in the isolation unit seem attuned to how their co-workers are viewing them. Some people who work in that unit are trying not to mingle with those who do not, several employees said. Even though the hospital administration has not explicitly ordered Ebola workers to stay away from others, employees said, the word has gone out through informal channels that it is better to lower the risk, and the anxiety quotient, of exposing other employees. Some nurses asked for arrangements to be made for them to sleep over at the hospital out of fears of passing the virus to their relatives and friends.
One Bellevue health care worker said that nurses who had not completed their Ebola training were asked on Friday to relieve the nurse taking care of Dr. Spencer’s fiancée, Morgan Dixon. At first they refused, the worker said. Then one “gowned up” and was relieved to find the work consisted of making sure Ms. Dixon’s temperature was taken and entered into a log. The worker and other Bellevue employees quoted spoke on the condition of anonymity because they did not have permission to discuss hospital matters.
Ms. Dixon, who has shown no symptoms, has since been discharged to home quarantine in the Hamilton Heights apartment she shares with Dr. Spencer.
Ana Marengo, a spokeswoman for Bellevue, said on Tuesday that everyone who worked with Dr. Spencer and Ms. Dixon had been fully trained.
DAKAR, Senegal (AP) — The rate of new Ebola infections in Liberia appears to be declining and could represent a genuine trend, the World Health Organization said Wednesday, but the epidemic is far from over.
The disease is still raging in parts of Sierra Leone and there is still a risk that the decline in Liberia won’t be sustained, Dr. Bruce Aylward, an assistant director-general for WHO, warned reporters.
Several times in outbreak officials have thought the disease’s spread was slowing, only to surge again later. Officials have often blamed those false lulls on cases hidden because people were too afraid to seek treatment, wanted to bury their relatives themselves or simply weren’t in contact with authorities.
But now there are some positive signs: There are empty beds in treatment centers in Liberia and the number of burials has declined. There may be as much as a 25 percent week-on-week reduction in cases in Liberia, Aylward said.
Throughout the Ebola outbreak, WHO has warned that its figures have been incomplete and the number of cases are likely vastly underreported. That is still a concern, Aylward said, but the trend nonetheless appears to be real.
“The epidemic (in Liberia) may be slowing down,” he said during a telephone press conference from Geneva. The slowdown could be attributable to a rapid increase in safe burials of Ebola victims, an uptick in the number of sick people being isolated and major public awareness campaigns on how to stop transmission.
So far, more than 13,700 people have been sickened in the outbreak, which has hit Liberia, Guinea and Sierra Leone hardest. More than 6,300 of those are in Liberia alone.
Aylward cautioned against reading too much into the decline, saying that any let-up in the response could allow the disease to surge again.
“Am I hopeful? I’m terrified the information will be misinterpreted and people would start to think, oh great, this is under control,” he said. “That’s like saying your pet tiger is under control.”
Liberia’s Red Cross said Tuesday that teams collected 117 bodies last week from the county that includes Monrovia, down from the high of 315 per week in September, and the government reported last week that only about half of the available beds in treatment centers were occupied.
Others were more reluctant to call the decline a trend.
Ebola outbreaks come in waves, warned Benoit Carpentier, a spokesman for the International Federation of the Red Cross. Red Cross figures show deaths are still increasing outside Monrovia, he noted.
It’s possible that at least some of the decline is because cases are being hidden — a phenomenon that has plagued the response to the outbreak since the beginning, said Ella Watson-Stryker, a health promotion manager for Doctors Without Borders in Liberia.
She said her team has heard of people doing their own burials in order to avoid a government order that Ebola victims in Monrovia be cremated; the government has also cited fear of cremation, a practice deeply at odds with Liberian tradition, as a reason beds are empty in treatment centers. Watson-Stryker added that people may be staying away from such centers because they are still confused about what kind of care is given at them.
However the decline is characterized, Aylward said the response must not relax.
“This hasn’t dropped off a cliff. … There’s a huge risk it wouldn’t be sustained,” said Aylward. “It would be a huge mistake … to think we can scale down the response.”
Instead, experts should redouble their efforts to track all of the people with whom the sick have come into contact — a task that has been nearly impossible in many parts of the outbreak because of the sheer number of infections.
There’s also tremendous work still to be done outside Liberia.
The western areas of Sierra Leone, near the capital, have seen a particularly steady increase in cases lately, and the country’s president has warned that Sierra Leone won’t win the war against the epidemic until people change their behavior, including avoiding touching the sick and the dead and quickly reporting to health centers if in case of illness.
On Tuesday night, the government numbers showed 26 new confirmed cases were reported in the country’s western districts, which include Freetown, during the previous 24 hours. Similar or higher numbers have been reported every day for those districts in recent days. In Bombali district, in the north, 32 new confirmed cases were reported.
“We’re seeing this thing burning quite hot in parts of Sierra Leone,” Aylward said.
Koroma said that areas in the country’s far east — where the outbreak first hit Sierra Leone — have seen a marked decline in cases because they are following the recommendations. Aylward gave a similar explanation, saying said there had been a reduction in risky behaviors and a willingness on the part of communities to help track and report cases.
The top U.N. official on Ebola, Anthony Banbury said Wednesday that the tremendous international response was beginning to pay off.
But Samantha Power, the American ambassador to the U.N., called on countries — especially those that had promised aid but not yet delivered — to do more.
“The U.S. is not running away from Ebola but walking toward the burning building,” she said, as she urged others to do the same. Power spoke alongside Banbury in Ghana, where the U.N. mission on Ebola has its headquarters.
(Reuters) – Nine cases of Ebola have been seen in the United States since the beginning of August. A Liberian man who died Oct. 8 in a Dallas, Texas, hospital was the first person diagnosed with the virus on U.S. soil.
The latest case is a doctor in New York City who was diagnosed on Oct. 23 within a week of returning from treating people in Guinea, one of the three worst-hit West African countries.
The following are details of cases of the hemorrhagic fever seen in the United States:
NEW YORK DOCTOR
Dr. Craig Spencer, 33, returned to the United States on Oct. 17 via Belgium after working for Doctors Without Borders charity in Guinea. He tested positive for Ebola on Oct. 23. His fiancée and two friends were put in quarantine.
Nina Pham, 26, a nurse at Texas Health Presbyterian Hospital, where she helped treat Liberian patient Thomas Eric Duncan. She was diagnosed four days after Duncan died. On Oct. 24 officials declared Pham free of the virus at the National Institutes of Health in Bethesda, Maryland, where she had been treated since Oct. 16.
A second nurse at the same hospital who treated Duncan, 29-year-old Amber Vinson, also tested positive for the virus. On Oct. 24 the Emory University Hospital in Atlanta where she was being treated declared her free of the virus.
Vinson flew from Ohio to Dallas the day before reporting symptoms, raising concerns about possible spread of the disease, which someone can get through contact with bodily fluids. Ohio has not reported any case of Ebola.
Ashoka Mukpo, an American freelance television cameraman working for NBC News in Liberia, was flown out of the country for treatment at Nebraska Medical Center in Omaha.
Mukpo, 33, was declared free of the virus on Oct. 21. “Recovering from Ebola is a truly humbling feeling. Too many are not as fortunate and lucky as I’ve been. I’m very happy to be alive,” he said in a Twitter post this week.
The NBC crew who worked with Mukpo also returned to the United States and were ordered into quarantine after violating their voluntary confinement.
LIBERIAN IN DALLAS
Duncan was visiting Dallas when he began feeling ill and sought treatment at Texas Health Presbyterian Hospital on Sept. 25. He was initially discharged with antibiotics, despite telling a nurse he had just come from Liberia. On Sept. 28 he returned to the same hospital by ambulance after vomiting outside the apartment complex where he was staying. Duncan died in an isolation ward 11 days later.
An unidentified American who contracted Ebola in Sierra Leone began treatment at Emory University Hospital on Sept. 9. The patient, who has asked to remain anonymous, was discharged on Oct. 19, the university said.
Three Americans contracted Ebola while working for Christian missionary organizations in Liberia and were flown to the United States for treatment. All have recovered.
Nancy Writebol contracted the virus in July while working for a SIM USA hospital with her husband, David, who was not infected. She was treated at Emory and discharged on Aug. 19.
Dr. Kent Brantly also was treated in isolation at Emory after contracting Ebola while working for Christian relief group Samaritan’s Purse. He was released on Aug. 21.
Dr. Rick Sacra, a Boston physician who was working for SIM USA, arrived in the United States on Sept. 5 and was treated for three weeks at Nebraska Medical Center.
Hospitals across the United States have been urged to watch for possible cases and to ask patients about their travels to help screen for the virus. Patients have been monitored in several states.
With Americans on edge about the potential spread of Ebola, it is easy to overlook another virus to which we have long been accustomed — influenza. According to estimates by the Centers for Disease Control and Prevention (CDC), the flu takes anywhere from 3,000 to 48,000 lives a year in this country, depending on the severity of the disease in a given flu season. But as lethal as the flu can be, the CDC reports that nearly 60 percent of adults and 43 percent of children were not vaccinated in the most recent reporting year.
Those numbers disappoint David Cennimo, an infectious disease physician and assistant professor of medicine and pediatrics at Rutgers New Jersey Medical School. Cennimo tells Rutgers Today that getting an annual flu shot is far more important than many people realize.
How dangerous is the flu, and why does it deserve our attention?
David Cennimo: A lot of people think of the flu as a pretty mild illness, right up until they get it themselves, and then they see how severe it can be. I have treated severe cases where patients have been in intensive care on a ventilator. In one case I remember from my medical training, the patient developed a severe secondary infection and died. The thing that struck me is people saying, ‘I don’t understand; it’s only the flu.’ When you see a severe case, as I have, you get a whole new respect for the illness.
What about people who consider themselves healthy? What incentive do they have to be vaccinated?
Cennimo: First of all, they’re helping to protect those who are most vulnerable — the very young, the very old and those with other medical conditions, including cancer and suppressed immune systems. People at highest risk are better protected if those around them are also protected. So are the rest of us. Even if you’re the young 35-year-old guy in the office, I don’t want you in the office with me, or on the subway or the bus, because you can get everyone sick if you’re not vaccinated. But even if that doesn’t move you, getting vaccinated also benefits you directly. Nobody wants to get the flu. Nobody wants to miss a week of work and feel miserable, so that’s reason enough for me.
There are people who insist that flu vaccinations do them no good, that they get the flu anyway. Some even claim they’ve gotten the flu because they’ve had a flu shot. How do you answer them?
Cennimo: Those are a couple of the more common arguments I hear. First, you can’t catch the flu from a flu shot. The virus in that vaccine is killed. There’s nothing replicating in there. You can catch influenza from someone else in the waiting room at the doctor’s office or pharmacy when you go for your shot. You need to remember that it usually takes up to two weeks before vaccines take effect, while the incubation period of influenza is only a couple of days. So in that situation, if you become infected you can get sick before the vaccine has a chance to work. That’s an incentive to get vaccinated as early as possible in the season, before lots of people around you are sick.
As for people getting the flu anyway despite being vaccinated, admittedly the vaccines are not always 100 percent effective, so it is possible. But usually people who make this complaint say, ‘I get the flu every year.’ I usually then realize they’ve never had the flu. We’re all going to have one or two colds this winter, and they could be accompanied by aches and a fever. That’s not influenza, which is far more severe, but they think it’s flu and claim the shot didn’t work.
Some people are also concerned about allergies to the vaccine, including egg allergies. This actually is very rare in the population but can happen. If they believe they are allergic, they should discuss it with their physician and may need a different type of vaccine. We generally hear from people worried about egg allergies. The research suggests that if you can eat scrambled eggs, you can safely get a flu shot.
There are different forms of flu vaccine, including a nasal spray for people who don’t like shots. What can you tell us about the spray vaccine?
Cennimo: The nasal flu vaccines are really interesting because unlike the injectables they are a live attenuated virus. The virus is alive but mutated in a way that can only replicate where it’s cold so it can’t go to your lungs and make you sick. It’s indicated for people from ages 2 to 49 as long as their immune systems aren’t compromised, because theoretically giving live virus to immunocompromised people presents a higher risk for them.
There actually are new data showing an advantage to giving 2-to-8-year-olds the nasal spray instead of an injection. They seem to get better antibodies, better protection — plus you’re not sticking them with a needle. But both the spray and injectable vaccine are fine. Any influenza immunity you get is good influenza immunity.
In this season when Ebola is so much in the news, how do you feel about all the attention is it getting?
Cennimo: Ebola is very scary. But people in the United States are frightened of Ebola for statistically very little good reason. It’s fear disproportionate to the risk. Influenza has far too little fear based on the risk. It’s fascinating to me to see social media panic and listen to people worried about Ebola who have never had an influenza vaccine, where statistically the thing you will get this year is influenza. You’ll probably do yourself and those around you the most good by getting a flu shot.
In the fight against Ebola, mapping fruit bat habitats could be one important step, says a geoinformatics researcher at Sweden’s Royal Institute of Technology.
Like the Black Death that ravaged medieval Europe, the Ebola virus’ progress through remote areas of West Africa is enabled by lack of understanding about the disease, including its causes and transmission.
Mapping technology however will give responders to the crisis in Africa the upper hand in stopping the spread of the deadly disease, says Skog, a researcher in geoinformatics at Sweden’s KTH Royal Institute of Technology.
Skog’s research has produced a method that medical professionals can use to visualise the geographical distribution of a disease over time. In his research, Skog has explored the relationship between geography and disease distribution in major epidemics of the past, including the Black Death, the Russian Flu pandemic of 1889, the Asiatic Influenza of 1957 and the swine flu. He says the historical data provides a basis for predicting the course of future epidemics and pandemics.
“My research and method can also be used to report the current state of a pandemic, or predict how extensive the spread will be. And where the disease will strike next,” Skog says.
In fact, the way in which Black Death spread during the mid 14th, century bears a no small resemblance to today’s Ebola epidemic, he says. Both diseases were hosted by small mammals — black rats and fruit bats, respectively. But ultimately it was humans that enabled its spread.
“The Black Death was very much depending on total lack of knowledge regarding the etiology of the disease and how to avoid further transmission,” Skog says. “That is also the case for the mainly remote locations where Ebola now is spread.”
Fruit bats are believed to be the natural hosts of Ebola. These bats are among the creatures that residents of rural West Africa hunt for “bush meat.” The disease is also spread by the droppings of the bat, and it is believed to have spread to other types of bush meat, as well as monkeys and pigs that are raised for slaughter.
“The local population is getting part of their nourishment from bush hunting, leading to contact with the virus that is transmitted via body fluids,” Skog says, suggesting that closer study of the fruit bat could provide vital answers.
“A guess of mine is that the number of infected fruit bats is a determining factor for an Ebola outbreak,” he says. “Are there any known factors that may have changed the ecosystem in favor of the bats? Are the bats affected by the virus too? Do fruit bats always carry the Ebola virus or is the virus fatal to them as well? If so the percentage of infected bats will vary over the years also depending on the immunology of the species.”
There are a number of geoinformation technology options available to public health organizations that have sent field crews to respond to the crisis. These, Skog says, including equipping field workers with hand-held GPS devices that feed a central database with data and findings regarding locations of bodies, possible infections and diagnosed cases personnel.
“The data can easily be centrally monitored and used for decisions and policies to mitigate the spread,” he says. “Using satellite imagery, population centers can be localized. Collected disease data can also be compared and analysed with environmental and climatologic data to support other efforts to control the spread.”
For instance, assuming that fruit bats are the reservoir for the ebola virus, Skog says it would be of interest to find out if the first detected cases in an outbreak are located in or close to a fruit bat habitat. “If the environmental and climatologic parameters for fruit bat habitats can be defined, there is a chance these habitats could be mapped using existing map data and satellite or airborne imagery,” he says.
“Then risk areas could be monitored and preventive measures could be performed by health authorities. If the natural reservoir is in fact some other animal, positioning the first cases in each outbreak would still give a clue about what to look for.”
CHICAGO (September 10, 2014) – Nationally, hand hygiene adherence by healthcare workers remains staggeringly low despite its critical importance in infection control. A study in the October issue of Infection Control and Hospital Epidemiology, the journal of the Society for Healthcare Epidemiology of America (SHEA), found that healthcare workers’ adherence to hand hygiene is better when other workers are nearby.
“Social network effects, or peer effects, have been associated with smoking, obesity, happiness and worker productivity. As we found, this influence extends to hand hygiene compliance, too,” said Philip Polgreen, MD, an author of the study. “Healthcare workers’ proximity to their peers had a positive effect on their hand hygiene adherence.”
Researchers at the University of Iowa’s Carver College of Medicine used a custom-built, badge-based system to estimate hand hygiene compliance and opportunities, as well as the location and proximity of every healthcare worker in the medical intensive care unit of the University of Iowa Hospital and Clinics during a 10-day period for 24-hours a day. Badges were randomly provided at the start of each shift to physicians, nurses and critical care staff. The badges collected information from healthcare workers within proximity and hand hygiene compliance when entering and exiting a patient room. In total, more than 47,000 hand hygiene opportunities were recorded.
The estimated hand hygiene rate was 7 percent higher (28 percent vs 21 percent) when healthcare workers were in close proximity to peers when compared with the rate when healthcare workers were alone. In general, the researchers found that the magnitude of the peer effects increased in the presence of additional healthcare workers, but only up to a point.
The authors note that the results speak to the importance of the social environment in healthcare and have important implications for understanding how human behavior affects the spread of diseases within healthcare settings.
A genetic region responsible for red blood cell invasion was among a small number of areas found to differ between the genomes of malaria parasites that affect chimpanzees and Plasmodium falciparum, the parasite responsible for the deaths of more than half a million children each year.
Out of a genome of approximately 5,500 genes, researchers found that most genes have directly equivalent counterparts between the human and primate parasites. However, portions of the P. falciparum genome that differed most profoundly from the P. reichenowi parasite that infects chimpanzees were found to encode proteins that help the parasite to bind to and invade red blood cells, which is where the parasite grows and multiplies.
“Discovering that the key differences lie in genes responsible for red blood cell invasion reassures us that we’ve been looking in the right place,” says Dr Thomas Otto, first author at the Wellcome Trust Sanger Institute. “Researchers have identified surface proteins as promising vaccine candidates already; and our finding adds more support, showing that it is the difference in the parasites’ surface proteins that determine which host it will infect.”
This is the first time that an essentially complete genome has been produced for a malaria parasite that infects such a close relative of humans. It provides the first systematic view of the differences between parasites that infect humans and those that infect our close relatives. Human malaria emerged from the Great Apes, so this comparison using chimpanzee malaria is the closest that scientists have come to a full catalogue of the changes associated with parasites switching from our primate relatives into humans.
Plasmodium parasites export proteins to the surface of red blood cells, allowing infected red blood cells to stick to the wall of blood vessels. In human malaria, the best characterised of these proteins are encoded by a highly variable family of genes, allowing the parasites to evade the host immune response and continue the infection. Surprisingly basic rules about this gene family are preserved between chimpanzee and human malaria: despite huge variation in the individual sequence of these surface antigen genes, their absolute numbers and the numbers of sub-types are remarkably preserved. By contrast, other surface antigen repertoires differed very significantly in their numbers.
“Since P. reichenowi and P. falciparum split apart, the major surface antigen gene family has not expanded or contracted; it’s locked at some kind of optimised level,” says Dr Matt Berriman, senior author at the Sanger Institute.
DNA used for this research was obtained by the Centre for Disease Control from a chimpanzee infected with a strain of P. reichenowi isolated in the 1950s. This chimpanzee was subsequently cured of the malaria infection. Additional blood samples were collected from orphaned infant chimpanzees infected in the wild with a similar parasite called P. gaboni. The samples were obtained from chimpanzees undergoing routine health checks at a primate sanctuary in Gabon, West Africa.
KUNMING, Sept. 7 (Xinhua) — As rabies sweeps across dog populations in China’s southwest Yunnan province almost 5,000 canines have been culled in an anti-rabies campaign.
With 5 human deaths in the past three months, the municipal government in Baoshan City is carrying out a campaign to stop the threat, with more than 4,900 dogs killed and 100,000 vaccinated.
The human casualties, one in July and four in August, were reported in four townships and villages in Shidian County. Longling County and Longyang District have also reported dog bites.
The municipal government of Baoshan has issued an urgent notice urging authorities to control the animals and cull stray dogs.
Rabies is a class 2 notifiable disease in China with cases rare in the past half-decade.
In 2006, at least 16 people died of rabies in east China’s Shandong Province after a rash of dog attacks.
The recall of raw pork products due to possible E. coli contamination has been expanded to more stores in Calgary and Edmonton.
Raw pork products bought at Trimming Fresh Meat (6219 Centre St. N.W.) between July 15 and July 22 and products from Hiep Hoa Asian Food (4710 17 Ave S.E.) between July 15 and July 29 should be thrown out or returned to the store where they were purchased.
According to the Canadian Food Inspection Agency website, the products may not look or smell spoiled, however they still have the potential to make consumers sick.
The expanded recall also includes frozen pork spring rolls, pork buns and pork wontons from Vihn Fat Food Products (10630 97 St.) in Edmonton sold between July 10 and Sept. 5, which should be thrown out or returned to the point of purchase.
Alberta Health Services said 153 people were diagnosed with E. coli between July 10 and Sept. 3, with 19 having to be hospitalized and five of those suffering the most serious form of the disease, which affects the kidneys.
AHS officials said 45 people were hospitalized in Calgary and 46 in Edmonton and the remainder at smaller centres around the province.
Steps can be taken to avoid food-borne illnesses, including washing your hands thoroughly using hot, soapy water — especially after using the washroom or changing a diaper — cooking pork and beef products to at least 71C (160F) and thoroughly washing any cooking utensils that touch raw meat.