Over the past two days, a very loud alarm has been raised over a mysterious disease that has killed 60 children in Cambodia:
http://www.flutrackers.com/forum/showthread.php?t=189109
I figured I would start this thread to keep speculation out of the news thread. Just a few thoughts as to possible diagnoses here:
Could this be an influenza? The reported CFR of over 98%, as well as the lack of clustering, seems to aruge against that. Could these just be the most severe cases of a much wider spread illness? Possible, but the age distribution argues against this. If there are thousands of milder cases, why would children be the only fatalities? What about bird-to-human H5N1? Hong Kong did just report an H5N1 case with neurological symptoms:
http://www.flutrackers.com/forum/showthread.php?p=457456
but that remains an atypical presentation. Moreover, I think that diagnosis would have the same problem; H5N1 kills people of all ages, not just children. Cambodia also seems to be able to detect human H5N1 cases.
What about a childhood illness? HFMD, chickenpox, and measles can all cause encephalitis and pneumonia, but have quite a low fatality rate, so you would need thousands of milder cases to make the CFR balance with this outbreak. Also, those three illnesses have characteristic rashes that should make them easy to identify.
How about an encephalitis virus from elsewhere in the world? JE, West Nile, and EEE come to mind, but they all have fatality rates under 50%, so you would still need hundreds of missed cases. Chandipura virus has produced outbreaks in children in Northern India with over 75% fatality rates, but that virus has never been reported in Southeast Asia. And it doesn't produce respiratory symptoms.
What about Nipah? That would explain both the encephalitis and respiratory symptoms, and while never reported from Cambodia, has been reported elsewhere in Asia. It also has had outbreaks of >75% CFR, so you wouldn't need that many milder cases. But Nipah affects all ages as well, and also can exhibit some H2H transmission, something this outbreak does not have. One might patch up the age issue by noting that previous Nipah outbreaks in Bangladesh have been associated with drinking unfermented juice that bats have contaminated. In Bangladesh, everyone drinks unfermented juice because of the Islamic prohibition against drinking alcohol. But in a non-Muslim country like Cambodia, might only children drink unfermented juice while adults drink theirs fermented (which reportedly kills the virus)?
Also on the encephalitis list for Southeast Asia would be rabies, which in these conditions would be universally fatal after symptoms appear. I can't imagine, though, what would cause only children to be exposed to rabies, and rabies produces no respiratory symptoms.
Neighboring Vietnam has reported a couple outbreaks in the past decade of a viral encephalitis it calls "acmong virus":
http://www.flutrackers.com/forum/showthread.php?t=44584
which causes encephalitis in children with about a 30% CFR. But that would require hundreds of missed cases, and there is not report in that thread of respiratory symptoms.
What about a hospital-acquired pathogen like KPC? That could cause both pneumonia and meningitis, and the news thread does indicate that all the patients sought previous treatment. But that should not produce this high an apparent CFR, and does not explain the age distribution (all patients in the hsopital would be exposed).
Could this be the result of a toxic treatment error? We have a report here on FT from Hurghada, Egypt, of three children dying of similar symptoms after a treatment error:
http://www.flutrackers.com/forum/showthread.php?t=167875
But what chemical could end up in a children's medicine that would produce this constellation of symptoms?
Could this be the inadvertent association of unrelated illnesses? As Mike Coston noted in his article in the news thread, Cambodia does have a very high child mortality rate. Could they inadvertently have grouped together the 60 most severe illness in chidren found in that part of the country in the past three months? Maybe, but I don't see any evidence that any of the cases have bee ngiven any diagnosis. I would think in that circumstance that something would come back positive on at least some of the cases.
Could this be related to the AES outbreaks in India and Bangladesh? In the past couple months, hundreds of children in India and at least 14 in Bangladesh have died of an unidentifed high CFR encephalitis:
http://www.flutrackers.com/forum/showthread.php?t=179078&page=3 [India]
http://www.flutrackers.com/forum/showthread.php?p=458701 [Bangladesh]
Could this virus have spread to Cambodia? Maybe, but I haven't seen any respiratory symptoms in either of those AES outbreaks.
At this point, I have way more questions than answers.
http://www.flutrackers.com/forum/showthread.php?t=189109
I figured I would start this thread to keep speculation out of the news thread. Just a few thoughts as to possible diagnoses here:
Could this be an influenza? The reported CFR of over 98%, as well as the lack of clustering, seems to aruge against that. Could these just be the most severe cases of a much wider spread illness? Possible, but the age distribution argues against this. If there are thousands of milder cases, why would children be the only fatalities? What about bird-to-human H5N1? Hong Kong did just report an H5N1 case with neurological symptoms:
http://www.flutrackers.com/forum/showthread.php?p=457456
but that remains an atypical presentation. Moreover, I think that diagnosis would have the same problem; H5N1 kills people of all ages, not just children. Cambodia also seems to be able to detect human H5N1 cases.
What about a childhood illness? HFMD, chickenpox, and measles can all cause encephalitis and pneumonia, but have quite a low fatality rate, so you would need thousands of milder cases to make the CFR balance with this outbreak. Also, those three illnesses have characteristic rashes that should make them easy to identify.
How about an encephalitis virus from elsewhere in the world? JE, West Nile, and EEE come to mind, but they all have fatality rates under 50%, so you would still need hundreds of missed cases. Chandipura virus has produced outbreaks in children in Northern India with over 75% fatality rates, but that virus has never been reported in Southeast Asia. And it doesn't produce respiratory symptoms.
What about Nipah? That would explain both the encephalitis and respiratory symptoms, and while never reported from Cambodia, has been reported elsewhere in Asia. It also has had outbreaks of >75% CFR, so you wouldn't need that many milder cases. But Nipah affects all ages as well, and also can exhibit some H2H transmission, something this outbreak does not have. One might patch up the age issue by noting that previous Nipah outbreaks in Bangladesh have been associated with drinking unfermented juice that bats have contaminated. In Bangladesh, everyone drinks unfermented juice because of the Islamic prohibition against drinking alcohol. But in a non-Muslim country like Cambodia, might only children drink unfermented juice while adults drink theirs fermented (which reportedly kills the virus)?
Also on the encephalitis list for Southeast Asia would be rabies, which in these conditions would be universally fatal after symptoms appear. I can't imagine, though, what would cause only children to be exposed to rabies, and rabies produces no respiratory symptoms.
Neighboring Vietnam has reported a couple outbreaks in the past decade of a viral encephalitis it calls "acmong virus":
http://www.flutrackers.com/forum/showthread.php?t=44584
which causes encephalitis in children with about a 30% CFR. But that would require hundreds of missed cases, and there is not report in that thread of respiratory symptoms.
What about a hospital-acquired pathogen like KPC? That could cause both pneumonia and meningitis, and the news thread does indicate that all the patients sought previous treatment. But that should not produce this high an apparent CFR, and does not explain the age distribution (all patients in the hsopital would be exposed).
Could this be the result of a toxic treatment error? We have a report here on FT from Hurghada, Egypt, of three children dying of similar symptoms after a treatment error:
http://www.flutrackers.com/forum/showthread.php?t=167875
But what chemical could end up in a children's medicine that would produce this constellation of symptoms?
Could this be the inadvertent association of unrelated illnesses? As Mike Coston noted in his article in the news thread, Cambodia does have a very high child mortality rate. Could they inadvertently have grouped together the 60 most severe illness in chidren found in that part of the country in the past three months? Maybe, but I don't see any evidence that any of the cases have bee ngiven any diagnosis. I would think in that circumstance that something would come back positive on at least some of the cases.
Could this be related to the AES outbreaks in India and Bangladesh? In the past couple months, hundreds of children in India and at least 14 in Bangladesh have died of an unidentifed high CFR encephalitis:
http://www.flutrackers.com/forum/showthread.php?t=179078&page=3 [India]
http://www.flutrackers.com/forum/showthread.php?p=458701 [Bangladesh]
Could this virus have spread to Cambodia? Maybe, but I haven't seen any respiratory symptoms in either of those AES outbreaks.
At this point, I have way more questions than answers.
