Category Archives: Sad

Polio outbreaks in Africa and Asia

Polio reports in 2013

Polio reports in 2013

The New York Times Health section had an alarming report today; public health officials with the World Health Organization have noted an outbreak of polio in Pakistan and in several African countries including Somalia and Kenya. Currently, the region has had approximately 50% more cases, in comparison to the same time in 2012, leading the Centers for Disease Control and Prevention to list the region in eastern Africa at Level 2-Alert, advising travelers to practice heightened precautions.  In addition to recommending travelers to this region of the world make sure to be up to date with their polio vaccine, they are also recommending travelers avoid any unpasteurized dairy as well as all public water sources.

The outbreaks are likely due to heightened political tensions in both of the regions. The outbreak in Pakistan is due to a regional warlord’s ban on vaccination 14 months ago, in retaliation to US drone strikes against Taliban insurgents. The outbreak in Somalia is due to the movement of refugees retreating from fighting between militias and government troops. The NYT article notes that this outbreak is particularly frustrating to public health officials in the region, as there is actually very little opposition to receiving the vaccine by the public at large there. Opposition to vaccination is actually coming from many of the tribal militias, who see door-to-door campaigns as undercutting their political legitimacy to rule in these areas. In Pakistan however, opposition is frequently directed at the vaccine itself, which has been rumored to cause sterility, or to contain pork products in its formulation.

Prior to this significant outbreak, public health organizations have been very optimistic about the likelihood that polio would be eradicated soon, and have a concrete plan to completely eliminate all wild cases of the virus within the next 5 years at a cost of $5.5 billion. While this outbreak does not put polio-free regions of the world including the western hemisphere at any significant risk, it does emphatically illustrate that eradication will not be straightforward.

Straying into politics

But it’s for the good of humanity! The two fine looking individuals to the right are of course Rep. Michelle Bachmann and Gov. Rick Perry, two candidates for the Republican nomination for President. They are having a bit of a disagreement at present, over Mr. Perry’s position as Governor of Texas that all girls should receive the Gardisil vaccination against Human Papilloma Virus, or HPV. Ms. Bachmann disagrees with that position, and feels that it should be the right of the individual to decide whether to receive a vaccination or not.  Her position on Monday’s debate was to say the this amounted to “government-mandated injection” and escalated her rant on Tuesday to claim that HPV vaccinations cause mental retardation.

I’ve previously put forward my firm position on the efficacy of vaccination, and so I won’t rehash those arguments in great detail here. The fact is, inexpensive, easily accessible, and high compliance vaccination is the single greatest improvement in public health in the United States in modern times. The last biggest sea-change in medicine was probably the elimination of blood letting in the Middle Ages.  But Michelle Bachmann probably won’t listen to me. Consequently, the American Association of Pediatrics came out with this terse press release:

The American Academy of Pediatrics would like to correct false statements made in the Republican presidential campaign that HPV vaccine is dangerous and can cause mental retardation. There is absolutely no scientific validity to this statement. Since the vaccine has been introduced, more than 35 million doses have been administered, and it has an excellent safety record.
The American Academy of Pediatrics, the Centers for Disease Control and Prevention, and the American Academy of Family Physicians all recommend that girls receive HPV vaccine around age 11 or 12. That’s because this is the age at which the vaccine produces the best immune response in the body, and because it’s important to protect girls well before the onset of sexual activity. In the U.S., about 6 million people, including teens, become infected with HPV each year, and 4,000 women die from cervical cancer. This is a life-saving vaccine that can protect girls from cervical cancer.

Short and to the point.  On seeing this news alert, I went to the Health and Human Services website to look at the most recent data for vaccine adverse reactions. According to the CDC Adverse Effect Reporting System, there were approximately 2800 adverse reactions to all of the different HPV vaccines in 2010, which included Gardisil, as well as several other vaccine derivatives against related pathogens. In the entire US last year, there were only 160 deaths associated with ANY vaccine, a fabulous rate considering the many tens of millions of vaccines administered last year. I did not calculate the number due to Gardisil, but assume less than 5% of the total, and you are left with 30 or so deaths. Contrast that with the 4000 deaths due to cervical cancer last year, out of 12,000 cervical cancer cases, and many of those cases will succumb to their cancer this year. That quick comparison says that you are 100 times more likely to die of cervical cancer in any given year than a once in a lifetime adverse Gardisil reaction.

As recorded in an interview with Sean Hannity, Bachmann declared ” I am not a doctor, I’m not a scientist, I’m not a physician.” You know what? I think that if you are going to preface your remarks with that kind of qualifier, perhaps you shouldn’t be making a scientific or medical pronouncement.  Leave those things to people who will actually take the time to examine cold, hard facts instead of anecdote and innuendo. And maybe use some logic and a bit of common sense as well.

Not the way to further medical research

Treponema pallidum: Image via Wikipedia

I received a link to a New York Times article from my microbiology colleague at the University of Delaware (thanks Dad!) about a truly horrific episode in American medicine. The story recounts the preliminary findings of a Presidential panel on bioethics that has been examining studies performed on Guatemalan inmates, soldiers, and mental patients during the 1940′s. These studies first came to light only very recently, and were publicized also in the New York Times, after being recovered from archives at the University of Pittsburgh.

The antibiotic penicillin was a novel weapon in the war against infectious disease in the first half of the 20th century, and physicians were extremely interested in determining the efficacy of penicillin against many different types of diseases. One disease of high import was syphilis, a venereal disease caused by the bacterium Treponema pallidum.  Penicillin turned out to dramatically reduce the prevalence of syphilis worldwide after the 1940′s, however the prevalence of the disease is increasing today, mainly due to unsafe sex practices in developing countries.  Read the rest of this entry

America’s bats: in danger!

Top: Three bats afflicted with White-Nose Syndrome Bottom:Section of wing stained to show fungal infection

The latest issue of Microbe magazine arrived in my mailbox the other day, with a fascinating article about the epidemic of White-Nose Syndrome among bat colonies throughout the northeastern United States.  Biologists first noticed in 2007 that bats in several caves near Albany, NY were dying during their winter hibernation. According to the report in Microbe, it has been estimated that more than 1 million bats have died from this epidemic to date, and that one extremely common species of bat, Myotis lucifugus, could become extinct within the next two decades if the epidemic continues.

Initial work has been to identify the causative agent of White-Nose Syndrome, and a novel fungal species, Geomyces destructans, has been proposed to be responsible.  Infection with this fungus causes an invasive skin disease (noted in picture “B” to the right), initially by colonizing the superficial layers. Later penetration of deeper layers by the hyphae (filaments) of the fungus leads to the formation of ulcers damaging the function of the wing.

The origin of G. destructan is at present unclear, although molecular evidence suggests that the fungus was accidentally introduced possibly by a tourist into a cave in New York. The fungus has been isolated from many sites in Europe, and polymerase chain reaction (PCR) analysis has indicated that many hibernating bats in Europe have been infected with the fungus. Unlike hibernacula in the United States, the European bats have not shown the precipitous decline in numbers that biologists are currently observing here. This raises the interesting question: what is different in the interaction between North American and European bats, and why is the interaction with the fungus leading to such a drastic difference in outcome? Read the rest of this entry

Emerging infectious diseases

I came across a report of an outbreak of Human Metapneumonia Virus, that was quickly ramping up to epidemic proportions in the population. The outbreak of hMPV will never reach pandemic proportions, because the population that is infected with the disease are the Mountain Gorillas of Rwanada, Uganda, and the Democratic Republic of Congo. Reserves in these 3 countries are home to the less than 800 gorillas that remain in the wild.

Habitat encroachment and poaching remain the two most significant dangers to the closely watched population, however the second most common cause of death in the gorillas besides trauma is infectious disease, which accounts for about 20% of sudden deaths.  The Centers for Disease Control report noted 4 respiratory outbreaks among human-acclimated gorilla groups, between May and August 2008, with an additional outbreak in one of the same groups the following summer.

In the group observed during 2009, 11 out of the 12 animals exhibited moderate to severe respiratory disease. Several of them were treated via remote administration of antimicrobial therapy, however one of the adult females succumbed while under observation. Post-mortem analysis of the gorilla indicated significant immune cell infiltration into the respiratory system, consistent with the presumed etiology of the disease. Microbiological analysis confirmed the presence of Streptococcus pneumoniae, Klebsiella pneumoniae, as well as genetic sequences from the aforementioned Human Metapneumonia Virus. Both S. pneumonia and K. pneumonia (unrelated organisms!) are found on humans in the absence of disease, but are significant opportunists. hMPV is an extremely common innocuous virus in humans, with an inferred prevalence of very close to 100% in most populations.  None of these agents are particularly harmful in immunocompetent individuals, however we have a very different situation in the simian population, with an immune system that is best adapted to deal with simian pathogens.

Molecular analysis of the hMPV sequences indicated they were very closely related to virus strains of South African origin, and that it was very unlikely that they came from the immediate caregivers in the gorilla preserves. The CDC report notes:

Although HMPV transmission as a result of human intervention to treat sick animals in the group is possible, it does not explain HMPV in the adult female, which died early in the outbreak before any clinical interventions were conducted. Although human proximity to mountain gorillas is essential for their conservation, also crucial is minimizing the risk for human-to–great ape transmission of respiratory pathogens.

The situation will continue to degrade, as the habitats shrink and human contact expands. I have no bonus opportunity to offer for us here, but appreciate any comments.

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