epidemiology
revere | January 26, 2009The peanut butter/peanut paste ingredient based salmonella outbreak has been in the news lately and we've discussed it here (and here, here, here, here, here). There are now about 500 reported cases and six deaths. That's a case fatality ratio of just over 1%. So what if there were a disease outbreak of 100,000 cases with a case fatality ratio of 20%? I think we'd be pretty alarmed. But it happened in 2005. And it happened in 2006 and 2007 and last year, 2008 And it's happening, now, too. It isn't salmonella or or even HIV/AIDS, although it is estimated to kill more people in the US than both…
revere | January 22, 2009Readers want to know what I think about the bird flu situation in China, where four human cases have been reported in the last couple of weeks. I haven't said anything about it so far, which is normal for me. I usually like to wait for more information. There are dedicated and smart flu bloggers out there who spend more time collecting scraps of information than I do. Check out fluwiki forum and CureEvents, for the latest word, all accurately reported by top rank flu bloggers like crof and Mike and a number of others (it is dangerous to start naming people because you inevitably leave out…
revere | January 11, 2009We've been blogging about flu for over four years. It's not a rare topic these days. But when we started we only found two other bloggers with an interest in the subject. One was the late (and much missed) Melanie Mattson at Just a Bump in the Beltway blog. The other was DailyKos frontpager DemFromCT. Dem is still on the front page at dKos and still on top of flu. He is one of the blogosphere's pre-eminent flu experts, being not only an accomplished blogger but a medical professional whose specialty is pulmonology. He sees flu up close, in the lungs of his patients. So whenever Dem writes…
grrlscientist | December 13, 2008tags: hypomania, bipolar disorder, manic depression, mood disorders, mental health, psychology
Image: Michael Witte/NYTimes [larger view].
Have you ever met a person who seems to be on a perpetual caffeine high, without all the shaking? You know the type, those few hyperactive extroverts who are always doing things or meeting people, who have an expansive and optimistic mood yet are easily irritated, and who have an overactive libido or who enjoy really risky pastimes, like jumping out of airplanes or climbing buildings. According to some reading I've been doing, these are apparently…
revere | December 4, 2008The 53 year old South African businessman arrived in Rio de Janeiro on November 23. Two days later he began to feel unwell. Today he was returning to South Africa -- in a zinc lined coffin:
Brazilian media reported officials as saying he may have been infected when he was a patient at a hospital in South Africa where four people died from a new strain of arenavirus, which also includes the germ that causes Lassa fever.
The health ministry said it had not confirmed that information, but said one of the suspected causes of death was the arenavirus, which is spread through the excrement or blood…
revere | November 19, 2008A congressionally mandated independent panel of scientists has just issued a report verifying what many of us have know since the early 1990s. Gulf War Syndrome (GWS) is real:
Gulf War syndrome is real and afflicts about 25 percent of the 700,000 U.S. troops who served in the 1991 conflict, a U.S. report said Monday.
Two chemical exposures consistently associated with the disorder -- one to a drug given to soldiers to protect against nerve gas and the other said to protect against desert pests -- were cited as causes in the congressionally mandated report presented to Veterans Affairs…
sporte | November 16, 2008Hospital cases of methicillin resistant Staphylococcus aureus (MRSA) have risen 33-fold during the past ten years in Washington state, yet our hospitals fail to identify or track cases in a systemic fashion (Seattle Times).
The Seattle Times began a three-part investigative report today describing the rise in MRSA incidence, the consequences for patients, and the failure on the part of our hospitals to take measures to address the problem.
According to the Seattle Times, six out of seven people get MRSA infections at some kind of health care facility. The spread could be contained if…
revere | November 8, 2008When I think of what happens in November I think of elections, Thanksgiving, the first snowfall, the advent of winter. I don't think about being killed by running into a deer. But November is apparently the most likely time for that to happen. And it happens to a couple of hundred people a year in the US:
In November, when it comes to avoiding deer collisions, it's not the one you see crossing the road that's likely to get you, according to a wildlife expert.
"It's the one that's chasing her," said Dr. Billy Higginbotham, Texas AgriLife Extension Service fisheries and wildlife specialist.…
revere | November 7, 2008So we have more Salmonella contamination out and about. This one is in dry pet food. But it wasn't the pets that were getting the Salmonella:
Salmonella-contaminated dry pet food sickened at least 79 people, including many young children, and could still be dangerous, the U.S. Centers for Disease Control and Prevention reported on Thursday.
Even though the affected brands have been recalled and the factory in Pennsylvania closed, pet owners could still have the cat and dog kibble in their homes, the CDC said.
[snip]
"Dry pet food has a 1-year shelf life. Contaminated products identified in…
revere | November 6, 2008Three years ago we discussed (we were still on blogspot then) a spreading outbreak of a mysterious disease in Sichuan (Szechuan), China. Any mysterious disease outbreak in China always raises warning flags since southern China is the incubator for influenza. The Chinese discounted the possibility of bird flu, saying it was instead a massive outbreak caused by the bacterium Streptococcus suis, Type 2, an important cause of disease in pigs. S. suis sometimes causes human menigitis or septic shock, but the final total of 215 cases and 38 deaths seemed atypical. But it turned out Chinese…
revere | October 3, 2008I went to medical school at a time when it was still affordable. Even though it was a private Ivy League university, tuition was only $1200/yr at the start and I had a half scholarship. Room was $33/month. Still, it was a long time ago and that was still real money for some of us, so I ate dinner in the cafeteria and often made lunch by heating up a 19 cent can of Spaghetti-O's on a hot plate in my room across from the hospital. Medical school classes didn't allow much time for part time jobs, so I supplemented my income working as a guinea pig and blood donor. Whenever open heart surgery was…
revere | October 2, 2008Scientists have been using genetic data to estimate when species first appeared for some time. The basic idea is to use differences between species and a guess as to how fast sequences change as a molecular clock, running it backward until they show the same sequence. The same trick can be done with viral genetic information. If you know the genetic sequence of a virus at one point in time and then at a later time you can make an estimate of how fast the clock is ticking. An analysis along these lines has just been done with a newly found lymph node sample from Kinshasa (Democratic Republic…
revere | September 30, 2008A fascinating paper in CDC's journal, Emerging Infectious Diseases has more details on a problem we first mentioned, on the basis of news reports, back in June. It's about a possible relationship between West Nile Virus infection and the mortgage crisis, but the paper also gives a dramatic example of how the physical, biological and social environment can affect disease patterns and risks in populations.
Infection with West Nile Virus is primarily a disease of birds. It is transmitted from bird to bird by mosquito bites and the disease is maintained by the cycling between birds and mosquitoes…
revere | September 29, 2008A new study of foodborne illness has just been published and has made quite a bit of news. The typical headline is something like: "Animals Farmed For Meat Are The No. 1 Source Of Food Poisoning Bug, Study Shows." That makes it sound like most cases of food poisoning are from a particular bug and that bug comes from farm animals. Although it is inaccurate, the stories beneath the headline don't do much to dispel it:
Researchers from Lancashire, England, and Chicago, IL, have discovered that animals farmed for meat are the main source of bacteria responsible for food poisoning.
They suggested…
revere | September 5, 2008When influenza viruses with different genetic make-up co-infect a cell there is the possibility that they will mix their genetic endowments. The influenza virus is designed to do only one thing: make a copy of itself. It does this by tricking the host's protein manufacturing machinery to use the virus's genetic blueprint to make a viral copy. Influenza genes come in eight discrete packages and at some point these genetic segments are naked in the cell. If the segments of two viruses are in the cell at the same time the segments can mix and match, with some of the segments of one virus being…
revere | August 29, 2008I used to joke that the only plan the Bush administration had for dealing with air pollution was to put all the free radicals in jail. If you don't know what a free radical is, it is a highly reactive form of a chemical, usually involving an unpaired electron. Radicals often are short lived intermediates in other reactions and can have half lives in the microseconds or less. In any event we're talking seconds. It is free radicals that are formed by ionizing radiation. They quickly react with whatever chemicals are in their vicinity and if that chemical happens to be your genetic material, you…
revere | August 15, 2008A couple of days ago we discussed the murky questions surrounding the death of accused anthrax attacker Dr. Bruce Ivins. At the center of stipulating the cause and manner of death were the procedures for filling out the state of Maryland's death certificate by the medical examiner. Determining and recording the cause of death is important for many other things besides the circumstances surrounding the unexplained deaths of anthrax attackers. In the US you can't legally dispose of a body without a properly recorded death certificate and it's a document survivors use for all manner of other…
revere | August 2, 2008A new article in the British scientific journal, The Lancet, suggests that seasonal influenza vaccines may not be effective in preventing community acquired pneumonia in people 65 years old and older. This is the group specially targeted by CDC for vaccination each year and, not coincidentally, an age group that includes me. So I have both a scientific and personal interest in the subject. This isn't new news. We've previously discussed the evidence that shows seasonal vaccines are less effective in the elderly a number of times (see here and here) over the last few years, but the proposition…
revere | July 31, 2008There's a tremendous amount of influenza A/H5N1 ("bird flu" virus) all over southeast asia and other areas where the virus is endemic in poultry. Where is this virus, exactly? We know it's in the infected birds and in their respiratory secretions and feces. We know it occasionally infects mammals (including humans). Is it found in the environment? We know very little about this, although there is good evidence it is in water where aquatic birds like ducks spend time and likely one way the virus is spread from bird to bird. In lab experiments, the virus remains intact on inanimate surfaces for…
grrlscientist | July 27, 2008tags: researchblogging.org, Bombus impatiens, Bumblebees, pathogen spillover, epidemiology, pollinating insects, greenhouses
Common Eastern Bumblebee, Bombus impatiens.
This species is often relied upon to pollinate commercial food crops,
such as tomatoes, that are often grown in agricultural greenhouses.
Image: Wikipedia Commons [larger view].
A mysterious decline in North American bumblebee populations is apparently the result of "spillover" of pathogen-infected commercial bumblebees, Bombus species, from agricultural greenhouses where tomatoes, peppers and cucumbers are commonly grown…