Stories tagged infectious disease

Dec
15
2008

Karl Pha feels like he is in prison—he has been confined to an Eau Clair Hospital. Mr. Pha has active TB and refuses to take his medicine. The medication causes extreme itching. I understand his unhappiness, but he has 5 young children. If he doesn’t care about his own life he should at least worry about his kids. TB is a serious disease. Public health officials are not only concerned about Mr. Pha’s health and his family’s health but also the development of an antibiotic resistant strain.

This case brings up a few questions:

  • Should public health officials have the authority to confine someone with an infectious disease?
  • How would you define a situation that requires confinement?
  • Who pays for this hospitalization or other confinement costs?

Minnesota has recorded its first culture-confirmed case of influenza for the 2008-09 season in a 39-year-old man from Chisago County. The man's illness was caused by the A (H1) strain of the virus, the Minnesota Department of Health reported today. The man's virus is a good match for this year's vaccine, health officials said.

It is not too late to get your influenza vaccine! The peak influenza season usually occurs in February and it takes only 2 weeks after the vaccination to develop immunity. The best news is this year's vaccination is a good match to the first confirmed case. For a full report from the Minnesota Department of Health see this link.

Government officials in Zimbabwe have (finally) declared a state of emergency in the cholera epidemic that has already sickened more than 12,000 people and killed more than 550. Caused by the Vibrio cholerae bacterium, cholera's hallmarks are massive watery diarrhea and vomiting, and people who die from cholera generally die from dehydration. It's a terrible cycle: people get cholera from a contaminated water supply (or food that's been tainted through contaminated water. They don't have clean water to drink, so have no means of safe rehydration, and they don't have safe sewage systems, so waste infected with the cholera bacteria goes right back into the water where it can infect others.

Cholera is rare in the developed world today, but it wasn't always. For a fascinating real-life epidemiological detective story about the deadliest cholera outbreak in London's history (in August, 1854), check out Steven Johnson's "The Ghost Map." Even if you're not into non-fiction, it's a great read. I couldn't put it down.

Oct
08
2008

A leg. With elephantiasis.: Or lymphatic filariasis, if you will.
A leg. With elephantiasis.: Or lymphatic filariasis, if you will.Courtesy otisarchives1
Y’all know about elephantitis, right? Sever thickening of the tissue in the legs and genitals, to the point of developing massive, lumpy appendages (like and elephant, I suppose). Not a condition you’d want to develop, right?

Well don’t sweat it, kids and adults—elephatitis doesn’t actually exist. There’s a big weight off your back (and legs and genitals).

Unfortunately, this silver cloud has a rainy lining: while elephantitis isn’t a real thing, elephantiasis is. And elephantiasis is pretty much exactly what I described above, only it’s often mispronounced as “elephantitis.” Oh, fudge.

Elephantiasis, basically, results the body’s own response to some foreign agent—sometimes irritants in the soil, but usually parasitic worms cause the massive inflammation. And maybe the worms sometimes prevent it too… (for more on that, take a look at this Buzz post from last month)

When you get tight down to it, elephantiasis isn’t great to have. It hurts, and it makes life more difficult. Millions of people around the world have the disease, and about 1.3 billion people (a fifth of the world’s population) are considered “at risk” for contracting the disease that causes elephantiasis.

However, the World Health Organization is making a push to distribute a cheap and simple cure for the disease to all at risk areas (the effort was described in a BBC piece today). It’s estimated that the project has prevented 6.6 million children from developing the condition, and halted its progression in another 9.5 million people.

The treatment is based on a couple different drugs, neither of which are mentioned in the BBC article, but I’m guessing that it’s referring to albendazole and ivermectin. These drugs are anti-parasitic, attacking the worms that cause elephantiasis. Getting rid of your worms is generally a good thing, and it should prevent the development of elephantiasis, but I bet that—as the article implies—it won’t eliminate elephantiasis once it’s in its severe form. So, you know, catch it early.

The WHO program hopes to more or less eliminate elephantiasis by 2020. Although there are no known cases of elephantitis, I’m afraid that one may stick around a little longer.

Sep
19
2008

You'll never guess what's in the can: This isn't Sable Sheets, by the way. Just some other pro-sniffer.
You'll never guess what's in the can: This isn't Sable Sheets, by the way. Just some other pro-sniffer.Courtesy Thomas Hawk
Oops. I forgot y’all are too cool to read the word “poopy” now and again. Maybe next time I’ll drop an S-bomb on y’all. Or I could write “sulfurous compounds,” or skatole, or indole. But where would that get us? Nowhere very graphic, certainly.

So, how would you like it if it was your job to sniff out human feces?

Well, I’m sorry, but the job has already been taken. Taken, no less, by a member of a group whose mission in this country seems to be to take jobs from honest, upstanding Americans. That’s right: dogs.

This particular dog is named Sable Sheets, and he hails from Lansing, Michigan. (He doesn’t actually have a last name, being a dog, so I gave him one.) Sable is a professional sniffer of crap. If sniffing human feces were an Olympic sport, Sable would be a gold medalist, if it were a martial art, Sable would be a ninja. It is a serious pursuit—Sable sniffs for the government.

Since he was a puppy, Sable has been trained to recognize certain smells: the odors of water contaminants. Earlier this week, we went over just how great at smelling dogs are. Sable needs to be a great smeller, because not only does he have to recognize chemical contaminants, like those that come from household detergents, but he also has to be able to distinguish animal feces from human feces. A little animal feces in the water is gross, but if Sable can detect human feces it’s a sign that there could be a failed and leaking septic system nearby. Aside from the other obvious issues involved with poop in your water, leaking septic systems can lead to E. coli contaminating rivers and streams. And we don’t want that.

Municipal governments hire Sable and his handler, a former K-9 officer, to check out catch basins, outflows, and manhole covers. If Sable gets a hint of duke, he barks and looks at his handler.

E. coli bacteria can, of course, be detected without the help of a dog, but only with the help of laboratory equipment. To find and test all possible sources of E. coli contamination in a water system would take a tremendous amount of time and effort. A dog like Sable—who, at the moment, might be one of a kind—can speed up the effort greatly. He’s like a miniature, mobile, furry lab. Based on the sample’s that have been sent to the lab on account of Sable’s barks, the dog is about 87 percent accurate.

His handler adds that Sable is “getting better; getting more refined.” Sort of like a connoisseur of fine wines, really, but with… you know.

Sep
05
2008

We're back in business here at the Science Museum (although the building is still closed to the public until next Friday), just in time to report some good news.

Ouch: Taking one for the team?
Ouch: Taking one for the team?Courtesy Spamily

The CDC reported yesterday that 77.4% of US children between the ages of 19 months and three years received all their recommended vaccinations in 2007. That's a slight improvement over the 2006 statistic. There are big regional variations in coverage, and children living below the poverty line are slightly less likely to be fully vaccinated, but overall less than 1% of US kids received no immunizations at all.

What are the recommended shots?

  • Four or more doses of diphtheria, tetanus toxoid, and any acellular pertussis vaccine, or DTaP
  • Three or more doses of polio vaccine
  • At least one dose of measles, mumps, and rubella (MMR) vaccine
  • At least three doses of Haemophilus influenzae type b vaccine
  • At least three doses of hepatitis B vaccine
  • At least one dose of varicella vaccine

Some folks don't vaccinate their kids--particularly against measles, mumps, and rubella (MMR)--because they worry that the vaccine is linked to autism. That theory has been debunked many times, in many countries, but it persists. On Wednesday, researchers from Columbia University and the CDC offered up another study showing zero causal relationship between the MMR vaccine and autism (or gastrointestinal problems.) So kids, roll up your sleeves at those back-to-school physicals and get your shots. It sucks, but it beats getting measles.

On the other hand, evidence is mounting to show that flu shots don't work well to protect people over 70. Older people have a lesser immune response to the vaccine and don't develop as much immunity. But the very old and the very young also account for the highest number of flu deaths. So what to do? According to the NT Times article:

"Dr. Simonsen, the epidemiologist at George Washington, said the new research made common-sense infection-control measures — like avoiding other sick people and frequent hand washing — more important than ever. Still, she added, “The vaccine is still important. Thirty percent protection is better than zero percent.”

Another way to protect the elderly is to vaccinate preschoolers. Not only are they likely to pick up the flu before other members of the family, but there's some evidence that preschoolers are actually the drivers of annual influenza outbreaks. Stop the flu in young kids, and you might just stop it for everyone else, too.

Aug
20
2008

This week two new findings were published about the 1918 influenza pandemic. The first looked at preserved lung tissue from soldiers that died from the pandemic. They examined 58 samples and found that in most cases the predominant disease at the time of death appeared to have been bacterial pneumonia. It is hypothesized that influenza virus damaged the cells of the tissue lining the lung allowing the bacteria to invade and eventually led to death of the host. The authors of the study concluded:

“if severe pandemic influenza is largely a problem of viral-bacterial copathogenesis [double infection], pandemic planning needs to go beyond addressing the viral cause alone (e.g., influenza vaccines and antiviral drugs). Prevention, diagnosis, prophylaxis, and treatment of secondary bacterial pneumonia, as well as stockpiling of antibiotics and bacterial vaccines, should also be high priorities for pandemic planning.”

Click here to read the original scientific article in the Journal of Infectious Disease or here to read a ScienceDaily news report

The second finding examined if people that survived the flu had antibodies against the 1918 influenza pandemic in their body. The researchers collected blood samples from 32 survivors age 91-101 years and found that all reacted to the 1918 virus, suggesting that they still possessed antibodies to the virus. One of the researchers, Dr. James Crowe Jr., stated

"The B cells have been waiting for at least 60 years – if not 90 years – for that flu to come around again. That's amazing…because it's the longest memory anyone's ever demonstrated."

The research team went on to see if the antibody protected against the 1918 strain of influenza by infecting mice with the influenza. Some had been treated with the antibodies – others had not. They found that the mice receiving the highest dose of antibodies survived and the others died. For a well written summary of the research in ScienceDaily click here.

Aug
06
2008

Researchers at Swansea University, in the UK, are developing an antibiotic that can fight the MRSA superbug. And they're using superbugs to do it. OK, not superbugs. They're using the secretions from the maggots of the common green bottle fly.

A cage match I'm not sure I want to see: Maggots secrete a compound that can fight superbugs, including 12 strains of MRSA, E. coli, and C. difficile.
A cage match I'm not sure I want to see: Maggots secrete a compound that can fight superbugs, including 12 strains of MRSA, E. coli, and C. difficile.Courtesy National Institutes of Health

Super gross? Sure. And you won't see an ad for this antibiotic (Seraticin) on TV anytime soon. It takes some 20 maggots to make a single drop of the drug. So scientists have to fully identify it, figure out a way to synthesize it in the lab, test it on human cells, and put it through a clinical trial.

In the meantime, using live maggots on infected wounds is a time-tested way of beating infections. Dr. Alun Morgan, of ZooBiotic Ltd, told the BBC,

"Maggots are great little multitaskers. They produce enzymes that clean wounds, they make a wound more alkaline which may slow bacterial growth and finally they produce a range of antibacterial chemicals that stop the bacteria growing."

How effective are maggots? The University of Manchester has been doing research on diabetic patients with MRSA-contaminated foot ulcers. The patients treated with maggots were mostly cured within three weeks. Patients who got more conventional treatment needed 28 weeks.

So give maggots a big shout out. And then check these other stories:
"NHS 'needs to use more maggots'"
Prescription insects
Fun with beetles

Researchers at the International AIDS Conference sifted through published papers on the risk of heterosexual HIV transmission. They say that while a popular estimate pegs the rate of HIV transmission through heterosexual sex at 1 per 1000 contacts, true rates of infectivity are all over the map and dependent on many variables. The infectivity rate for certain sorts of activities is much, much higher-- as high as 1 in 3 contacts. The take away message? "Claims in both the popular media and the peer-reviewed literature that HIV is very difficult to transmit heterosexually are dangerous in any context where the possibility of HIV exposure exists."