infectious disease
revere | November 2, 2007Immigrants traditionally get blamed for a country's ills and historically they have been feared for their ability to bring disease as well. The recent cases of the traveling lawyer (and here, passim)and the Mexican businessman with TB raised concerns that tuberculosis would be brought to the US or other low TB incidence countries by immigrants or travelers from countries where TB was prevalent. Now a new study from Norway suggests this doesn't happen:
Immigrants from countries with high rates of tuberculosis who move to countries of low TB incidence do not pose a public health threat to…
revere | November 1, 2007I've just returned from a short trip to the Emiglia Romagna region of northern Italy. The area around Bologna (site of the world's first medical school) is said by most Italians to have the second best food in all of Italy (the best is usually "Grandma's house"). It also has chikungunya, an imported arbovirus infection whose vector is the Tiger mosquito, Aedes albopictus.
This nasty little daytime biter was first seen near Genoa (on the other side of Italy near the French border) in 1990 but was seen in the Veneto (the region next to Emiglia Romagna) in 1992, apparently on tires imported from…
tsmith | October 31, 2007 Salmonella species are frequent human pathogens. An incredibly diverse genus, different types of Salmonella infect an enormous variety of species, from mammals to fish to invertebrates. They are typically acquired via ingestion of contaminated food or water, and the bacteria then seed the intestine and replicate there. These gram-negative organisms are the cause of typhoid fever (Salmonella enterica serovar typhi) and can also cause acute gastroenteritis (multiple types, including Salmonella enterica serovars enteritidis and typhimurium).
Of these types, S. typhi is the most deadly,…
revere | October 29, 2007If you've heard of the disease distemper it may be because you had to get your dog vaccinated against it. Dog or canine distemper is caused by a measles-like virus, Canine Distemper Virus, but it doesn't just affect dogs. It is capable of jumping to other species and wiped out about 10% of the world's smallest seals, the Caspian seals. Other carnivores that have taken a big hit from CDV are the Tasmanian tiger and black-footed ferret. It can infect infect lions and hyenas and probably other animals in the wild. So the question of what enables the dog virus to jump to other species is not just…
tsmith | October 23, 2007It's only taken 30 years, but information about Ebola in nature is finally starting to snowball. First, after almost 15 years of disappearing from the human population, Ebola returned with a vengeance in the mid 1990s, causing illness in 6 separate outbreaks in Gabon, Ivory Coast, Democratic Republic of Congo (DRC), and South Africa (imported case) between 1994 and 1996. As doctors and scientists rushed in to contain the outbreaks, they were also able to collect viral samples, and trap animals and insects in the area, searching for a reservoir for the virus. In this decade, there have been…
revere | October 23, 2007If you have or have had small children you may be all too familiar with earaches. When our kids were small we felt as if we were single-handedly supporting the amoxicillin makers. A major cause of middle ear infection is the organism Streptococcus pneumoniae (S. pneumoniae), which sometimes it invades other tissues and causes bacterial meningitis (not the kind that you read about killing healthy teenagers, but bad enough) and sometimes other body sites. It is also a cause of pneumonia in adults and was a common cause of secondary bacterial pneumonia in the 1918 flu. That was then. Now there…
revere | October 22, 2007Human infection with West Nile Virus (WNV) first made its appearance in the US in 1999 in, of all places, Queens, New York. Humans are an incidental host of the virus which circulates in small land based birds, passing between them via mosquitoes. It's hard to find a place to bite a bird if you are a mosquito, but a number of species know just where to look. There is a rim around the eye, for example, where the bird's blood is accessible via a bite. The female mosquito needs the protein in blood to ovulate. Sometimes the mosquito also bites a human and a WNV infection can occur in a human,…
tsmith | October 18, 2007 A few news stories hit my inbox all at once yesterday--and the combination of them doesn't bode well for childrens' health; more after the jump.
First, despite several years now of banging the drum for having kids vaccinated against influenza, they're still being overlooked when it comes to pandemic planning:
Children would likely be both prime spreaders and targets of a flu pandemic, but they're being overlooked in the nation's preparations for the next super-flu, pediatricians and public health advocates reported Wednesday.
The report urges the government to improve planned child…
revere | October 18, 2007Almost everyone now seems to think the Iraq debacle was, well, a debacle. Many of us thought invading Iraq was a terrible idea to begin with. Others are silent on that issue (or approved) but think it was carried out poorly. No planning. Failure to plan, however, is a hallmark of the Bush administration. Their intentions are pre-programmed but they never seem to plan for the consequences of those actions. It's not just Iraq. Or Katrina, for that matter. It's also pandemic flu:
When you ask federal officials around the country if they are prepared for a pandemic flu, the answers are unsettling…
tsmith | October 16, 2007Revere weighs in regarding the Ferrell case. He also mentions one ironic point regarding bioterrorism history and one of the bacteria used, Serretia marcescens, that I hadn't thought to mention.
tsmith | October 15, 2007Being a microbiologist can be a dangerous business. Some of us work out in the field, exposed to weather, animals, and pathogens of all different forms. Some do research in countries with unstable governments, collecting samples and tracking down infected individuals in the midst of strife, poverty, and warfare. Some remain in the lab, but share it with agents that can be handled only under high levels of containment, and may need special labs and permits just to do their research. We all realize our job contains some level of risk, and do what we can to minimize that.
However, as much…
tsmith | October 15, 2007A few stories elsewhere on vaccines, zoonotic disease, a new Gates initiative, and the environment that deserve your attention:
Paul Howard on what we need to do about vaccines. Like Greta's article, Howard notes the short memories of many vaccine opponents, and also discusses the effect litigation has had on the vaccine industry--and what needs to be done to repair it.
Bill Gates once again: now he's funding $100 million worth of grants, up to $100K apiece, to include high-risk projects and non-traditional scientists:
Scientists, who need not have specific degrees or qualifications, will…
revere | October 8, 2007The US invasion of Iraq has not managed to spread Democracy in the region but it is successfully spreading Cholera:
The number of cholera cases in Iran is on the rise after the outbreak of an epidemic in neighbouring Iraq, an Iranian health official was quoted as saying on Saturday.
"The last count shows 43 people have contracted cholera in Kordestan province," Mohsen Zahrai, who is in charge of water and food-borne diseases, told ISNA news agency.
He said those affected had been commuting across the border with Iraq and warned Iranian citizens to postpone pilgrimages to Iraq until the…
tsmith | September 29, 2007In another case of TV shows being prescient, abuzz here at other Scienceblogs is this story, which sounds like a bad B movie: " 6 die from brain-eating amoeba in lakes." The amoeba in question is a species of naegleria, which was featured on the medical drama House last year. According to the article:
Beach said people become infected when they wade through shallow water and stir up the bottom. If someone allows water to shoot up the nose -- say, by doing a somersault in chest-deep water -- the amoeba can latch onto the olfactory nerve.
The amoeba destroys tissue as it makes its way up…
revere | September 29, 2007There's a polio problem in Nigeria. You may have heard that. Unfortunately what you haven't heard -- and what one could even characterize as a cover-up -- is that among the many cases of polio in northern Nigeria and surrounds, there are also 69 cases of paralytic polio in children from the type 2 vaccine strain:
Nigeria has found 69 cases of children paralyzed by polio not caused by wild polio viruses, but rather weakened viruses from polio vaccine that have circulated and regained their power to cause disease, a team of international scientists reported Thursday.
The ongoing outbreak in…
tsmith | September 27, 2007Via PZ, I see that yet another Catholic bishop in Africa is claiming that condoms are laced with HIV:
The head of the Catholic Church in Mozambique has told the BBC he believes some European-made condoms are infected with HIV deliberately.
Maputo Archbishop Francisco Chimoio claimed some anti-retroviral drugs were also infected "in order to finish quickly the African people".
His answer to AIDS is, of course, marriage, fidelity, and abstinence...which is all well and good, but not always possible or realistic. (Not to mention, what about an HIV-infected spouse?) WWJD?
[ETA: ERV has a…
tsmith | September 27, 2007 I asked yesterday what readers considered the most important diseases in history. This was prompted by a new ASM Press book, Twelve Diseases that Changed Our World, written by Irwin Sherman.
As I mentioned, Sherman included many diseases readers expected--plague, cholera, tuberculosis, smallpox, syphilis, malaria, influenza, yellow fever, and AIDS. He didn't include a few that popped up repeatedly in the comments--leprosy, measles, and typhoid (or typhus, for that matter). While I think a study of these could have been illuminating (especially leprosy, since much of the stigma…
revere | September 27, 2007It's not nice to get mumps. Mumps is caused by a paramyxovirus. Since the introduction of the measles-mumps-rubella vaccine most people have been spared the unpleasantness of the swollen, inflamed an painful salivary glands, or in older individuals, the systemic complications like orchitis (inflamed testicles) that can sometimes cause sterility in young males. It can also inflame the ovaries or breasts in females. It is contagious through the respiratory route and infected people shed virus three days before they get symptoms until up to nine days after symptoms start. So vaccination is the…
revere | September 26, 2007If you are in the elderly population (over 65 years of age) you are in the crosshairs of CDC's influenza vaccination program. The reasons seem clear -- at first, anyway. Risk of influenza-related death (as measured by a specific statistical technique to estimate excess mortality during influenza seasons) increases dramatically after 65 tears of age. If you are over 80, for example, your risks of being in the excess death category is more than ten times those in the age 65 - 69 age group. Three-quaters of the flu related deaths in a normal flu season are in the 65 plus group and more than half…
revere | September 24, 2007The National Health Interview Survey (NHIS) is the major source of information about the health of noninstitutionalized Americans -- you and me and our neighbors. Data collection started in 1956 and consists of ongoing data collection and special studies on illness and disability and their trends. Data is done using a questionnaire given to a representative household probability sample of the US population. If you want the gory details you can find them here. A recent report, presented in the CDC Morbidity and Mortality Weekly Reports (MMWR) QuickStats format, gives the estimated percentage…