H1H1 Super Spreader in India?

[HenryN]

Re: H1H1 Super Spreader in India?

H1N1 flu reaches Panchgani school, 17 test positive

TNN 28 July 2009, 01:46am IST
<!-- google_ad_section_start -->PUNE: As many as 17 students from a prominent boarding school in Panchgani have tested positive for the H1N1 flu, following which all 360 students at the school were screened for the virus on Monday. However, the school will not be shut, the principal affirmed.

Thirty-four students at the school, all aged between 10 and 16, had complained of fever and backache three weeks ago and were given regular flu medicines. They were admitted to the school's 18-bed hospital on July 23, said Vijaysinh Mohite, Satara district health officer. "The throat swab and nasal samples of all 34 students were sent to National Institute of Virology (NIV) in Pune the same day," he added.

The NIV report confirmed the presence of the virus in 17 students. However, since the students were already on medication, all of them, barring two, had fully recovered. The two students who haven't recovered have been quarantined and are being administered Tamiflu at the school's hospital.

Mohite said it was likely that one of the infected students may have returned from abroad recently and transmitted the virus to the others. Earlier, 22 students had gone on a study tour to NASA, returning some time in April. "However, it's been three months since they returned, so the chances of them transmitting the virus now is ruled out," he added.

The principal of the school told TOI that many boarders had gone out with their parents on the July 18-19 weekend. "There is a possibility that some of the students came in contact with outsiders carrying the virus. Besides, Panchgani is a tourist spot," he said.

Of the 360 students in the school, 56 are day scholars while the rest are boarders. Among the boarders are 10 non-resident Indian students.

Meanwhile, the school's interim examinations that were to begin on Tuesday have been postponed.

http://timesofindia.indiatimes.com/articleshow/msid-4827726,prtpage-1.cms

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[HenryN]

Re: H1H1 Super Spreader in India?

Although this school is near Pune, it is directly tied to the other cases. However, once testing begins for "community transmission", new unconnected cases appear.

[oldman]

Re: H1H1 Super Spreader in India?

Henry, I think there is some confusion as to what a "super spreader" is, judging by the responses we have seen posted. In my mind, there are two types of super spreaders. One is a person that comes into contact with many people, due to travel, etc. The other is a person who is so infectious, due to viral load, titers,etc., that they infect virtually every person they come in contact with. The situation in Pune where many people were infected and displaying symptoms on the same date would indicate the second type I described above. Am I out of line here, or is this a reasonable assumption/description?

oldman

[AlaskaDenise]

Re: H1H1 Super Spreader in India?

Oldman, you bring up a good point. Clarification of terms is probably in order.

I will however, add to your list - "superspreader" has also been used to describe a person who is an asymtomatic carrier, who sheds virus for a long period. Dr. Robert Webster wrote about this possiblity with HIV/AIDs patients - apparently some AIDs patients had prolonged infectious periods because their immune system could not clear a virus as quickly as someone with a healthy immune system. There is speculation as to whether these people will die quickly or live longer and be "superspreaders" either with or without symptoms.

.

[oldman]

Re: H1H1 Super Spreader in India?

Thank you, Denise. I am trying to learn all I can. Thanks again.

oldman

[HenryN]

Re: H1H1 Super Spreader in India?

Zoomed view of Pune cases

http://flutracker.rhiza.com/flu/gmap0907271655.html?lat=18.507772857118585&lon=73.828125&zoom=13

[AlaskaDenise]

Re: H1H1 Super Spreader in India?

Can Some Individuals Transmit SARS More Widely Than Others?

Wall Street Journal - April 10, 2003
Trish Saywell, Staff Reporter of The Wall Street Journal


--------------------------------------------------------------------------------
Top disease specialists are debating the theory of whether some people with SARS might be "superinfectors" or "superspreaders" -- that is, unusually contagious and able to transmit the illness to larger numbers of people.

Robert Breiman, head of a World Health Organization team investigating severe acute respiratory syndrome in China's Guangdong province, said one patient with the virus spread the disease to more than 30 people, two of whom died.

He recovered, but only one of the 30 people he infected went on to transmit the illness, and that person infected just two others, who didn't pass it on to anyone else. "There are stories like that," Dr. Breiman says. "We're hoping to get them to look more closely at superspreaders."

Singapore Health Minister Lim Hng Kiang used the term in describing a Singaporean woman who contracted SARS at Hong Kong's Metropole Hotel as one of several "superinfectors." Her infection triggered a chain reaction that sickened 50 family members, friends and close contacts, along with 56 health-care workers, and led to several deaths, including those of her parents, according to Singapore's Ministry of Health.

The woman was one of three Singaporeans who contracted the malady at the hotel, but the only one of the three who appeared to have transmitted the disease to others.

"They all got it from the same source but two of them didn't cause a lot of problems while the third one did. I don't think it's totally happenstance," says Henry Niman, a Harvard University instructor in surgery at Massachusetts General Hospital in Boston who has studied retroviruses.

Dr. Niman argues the number of superinfectors is low as a percentage of the total SARS population and that they "stick out like sore thumbs."

While he concedes he doesn't know what would make superinfectors so infectious, he speculates it could be any number of reasons, including that they have a variant of the virus or shed more of the virus than others.

What is the medical evidence? Julie Gerberding of the U.S. Centers for Disease Control and Prevention says the Atlanta agency is looking into the notion. "It may be that certain individuals are more efficient at transmitting the virus than others, and that is a matter of chance or other factors that we haven't figured out yet," she told reporters.

What is known is that a person is most likely to be infectious when they have symptoms of the sickness, such as a fever, aches and cough. It also appears that people are more infectious when they become more seriously ill. In Toronto, physicians believe that one patient spread SARS to 20 or 30 people in a short period of time.

Toronto's outbreak, the biggest in any city outside of Asia, accelerated largely because of one such spreader who was treated at Scarborough-Grace Hospital on March 16 and 17 without respiratory precautions, said Colin D'Cunha, Ontario's public-health commissioner.

Doctors still are trying to piece together links among all of those who got sick at the Toronto hospital. Some appear to have contracted the malady without ever coming into direct contact with SARS patients, raising the specter of airborne, rather than droplet, transmission in rare cases, says Allison McGeer, director of infection control at Toronto's Mount Sinai Hospital and a consultant at Scarborough-Grace.

Such a spread could be explained if some patients were more infectious than others, she said. Dr. McGeer says she doesn't believe the virus spreads by lingering on surfaces, such as elevator buttons.

"This is not a physical structure thing," she says. So far, there have been more than 2,900 suspected cases of SARS world-wide, mainly in Asia, with at least 106 deaths. Although the U.S. has about 150 suspected cases, there have been no deaths from the disease, which is believed to be caused by a new variant of the coronavirus.

Some medical experts contend the superinfector idea is misleading. Their seemingly higher transmission rate could simply be because of circumstances such as having contact with greater numbers of people while in the most-infectious stage or to practicing poor hygiene and not covering mouths or noses when coughing and sneezing.

"There's no definite evidence that there are superspreaders in SARS," says David Bell, a public-health physician with the WHO in Manila. "It's very difficult to prove that one person is putting X amount of virus particles out and the next one isn't putting as many virus particles out."

Nonetheless, Dr. Bell says the jury is still out and "it's possible" some people spread the SARS virus more efficiently than others. "We can say that there appears to be some people who have spread the infection to a lot of others. But we can't say whether they are intrinsically different or whether they've been in circumstances that have promoted that spread," he says.

People could spread more viral agent than others if their immune systems are suppressed or compromised by diseases such as HIV, or severe kidney and liver disease. For other SARS watchers, it is more a matter of actions and bad timing that could make some people seemingly more infectious than others.

"There is no such term [as superspreaders] in medicine," says Stephen Berger, an infectious-diseases expert at the Tel Aviv Medical Center in Israel. "There are people who by circumstance can transmit it more easily than others. If you have a person with HIV who runs around doing things he isn't supposed to, then he's going to become a superinfector."

Dr. Berger says everyone may have the same opportunity at some point to infect other people to a high degree. For instance, with chicken pox, "everybody is a superinfector when they go through the most-infectious stage of the disease," he says. People also may have an infectious disease and be virus carriers without symptoms, he says.

They may even feel well enough to stick to their normal daily routines and become "ticking time bombs," who could easily fall under the definition of a "superinfector," he says.

--David Murphy and Elena Cherney contributed to this article.

Write to Trish Saywell at trish.saywell@wsj.com

http://www.aegis.org/news/wsj/2003/WJ030406.html

[HenryN]

Re: H1H1 Super Spreader in India?

Henry, I think there is some confusion as to what a "super spreader" is, judging by the responses we have seen posted. In my mind, there are two types of super spreaders. One is a person that comes into contact with many people, due to travel, etc. The other is a person who is so infectious, due to viral load, titers,etc., that they infect virtually every person they come in contact with. The situation in Pune where many people were infected and displaying symptoms on the same date would indicate the second type I described above. Am I out of line here, or is this a reasonable assumption/description?

oldman

There are multiple definitions of super-spreaders, but I was using it to describe a person who is very infectious. I was going through the daily reports of cases in India and was struck by the fact that 10 of 10 Pune cases reported on Saturday were all due to contact, so I started this thread. Upon further investigation, it seems likely that those 10 (as well as the 5 the next day) were linked to the school outbreak(s) and not necessarily due to 1 or 2 superspreaders.

However, the number of cases keeps increasing, so there may be multiple superspreaders because the virus is transmitting efficiently. The outbreaks have been clustered (those sharing a rickshaw or those in the same grade at the same school).

This clustering has been reported previously (in the NY high school 150 students developed symtoms over a 2 day period and some summer camps involve clusters who road the same bus).

It is clear that under some circumstances the virus is transmitting quite efficiently, which is a concern, especially since this transmission is in the summer, and the virus is more stable at lower temperatures.

This type of clustering is a concern, and it is more of a concern in densely populated areas, which is why the situation in Pune is being closely monitored.

[AlaskaDenise]

Re: H1H1 Super Spreader in India?

Host Species Barriers to Influenza Virus Infections

(snipped)

The fate of an epidemic can also depend strongly on heterogeneities in R0, particularly on the role of "superspreaders" early in the epidemic (32). For example, some superspreader individuals may be more infective per contact for some reason; other superspreaders may not have higher per-contact transmission, but have many more contacts and therefore greatly multiply the rate of spread (22). If superspreaders become infected early in an outbreak, the epidemic is more likely to take off, which can have substantial implications for disease control (32).

http://www.sciencemag.org/cgi/content/full/sci;312/5772/394

[oldman]

Re: H1H1 Super Spreader in India?

Many thanks to Denise and Henry for setting us all straight.

oldman

[Hogweed]

Re: H1H1 Super Spreader in India?

There are multiple definitions of super-spreaders,.

Can "super-spreader" also refer to an event as opposed to an individual?

[Aeolus]

Re: H1H1 Super Spreader in India?

From post "12" on this thread: The number of swine flu victims in the city suddenly shot up after some students returned from a trip to Indiana, US. The schools will remain closed till August 2.

Background on the brother: Health department officials on Friday said 19-year-old Matthew McIntosh died from the viral infection July 5 at University Hospital.

McIntosh was found June 28 in a barn near his Dearborn County home and brought to Cincinnati two days later for treatment.


HT-> PFI-HMD

Woman Dies From Viral Infection That Killed Brother
Dearborn Co. Siblings Killed By H1N1 Infections

http://www.wlwt.com/health/20195033/detail.html

CINCINNATI -- An Indiana woman died Monday from H1N1, the same virus that killed her brother last month.

Relatives confirmed that 26-year-old Mindy McIntosh, of Dearborn County, had lost her battle with the viral infection.

Her 19-year-old brother, Matthew McIntosh, died June 30 from the virus at University Hospital after collapsing near a barn at his family's home.

Health officials have not released any information about how the siblings might have contracted the viral infection.

Nationally, there have been 170 deaths related to the pandemic H1N1 flu.

Physicians said the virus can be prevented using proper hygiene, such as covering coughs and sneezes and thorough hand washing.

[alert]

Re: H1H1 Super Spreader in India?

From post "12" on this thread: The number of swine flu victims in the city suddenly shot up after some students returned from a trip to Indiana, US. The schools will remain closed till August 2.

Background on the brother: Health department officials on Friday said 19-year-old Matthew McIntosh died from the viral infection July 5 at University Hospital.

McIntosh was found June 28 in a barn near his Dearborn County home and brought to Cincinnati two days later for treatment.


HT-> PFI-HMD

Woman Dies From Viral Infection That Killed Brother
Dearborn Co. Siblings Killed By H1N1 Infections

http://www.wlwt.com/health/20195033/detail.html

CINCINNATI -- An Indiana woman died Monday from H1N1, the same virus that killed her brother last month.

Relatives confirmed that 26-year-old Mindy McIntosh, of Dearborn County, had lost her battle with the viral infection.

Her 19-year-old brother, Matthew McIntosh, died June 30 from the virus at University Hospital after collapsing near a barn at his family's home.

Health officials have not released any information about how the siblings might have contracted the viral infection.

Nationally, there have been 170 deaths related to the pandemic H1N1 flu.

Physicians said the virus can be prevented using proper hygiene, such as covering coughs and sneezes and thorough hand washing.

This is likely a coincidence. I doubt the Indian tourists in Indiana were visiting Moores Hill, a town with a population of under 1000. And the contacts of the Mcintoshes were in Cincinati (Ohio) across the border.

[wotan]

Re: H1H1 Super Spreader in India?

This is likely a coincidence. I doubt the Indian tourists in Indiana were visiting Moores Hill, a town with a population of under 1000. And the contacts of the Mcintoshes were in Cincinati (Ohio) across the border.

Its a stretch, but Matt did collapse at a concert. I don't think they ever followed up on that, they are too busy with the barn misdirection.

[alert]

Re: H1H1 Super Spreader in India?

Its a stretch, but Matt did collapse at a concert. I don't think they ever followed up on that, they are too busy with the barn misdirection.

It was a concert he was performing at. I'm sure he did infect others at the concert (he infected at least one other member of the band), but if he had some kind of mutated virus, we would be hearing all kinds of trouble out of Cincinati by now. Remember, he was treated WITHOUT ISOLATION PRECAUTIONS in University of Cincinati hospital for over a week,