Monday, July 25, 2016

Prisoners, chimpanzees and HIV infection

This post is devoted to HIV transmission. The opportunity is given by two occurrences, a research paper published on the July 14 issue of The Lancet  "HIV, prisoners, and human rights" and a press release issued on July 22 by the University of Nebraska-Lincoln concerning a study on cross-species HIV infection. The Lancet paper discusses the spread of infectious diseases, and notably HIV infection, in prisons. Researchers focus on (dis)humane prison conditions and human right abuse. HIV infection is as inherent to the criminal justice system as researchers come to state that HIV infection is almost an atrocious additional punishment. Moreover, the spread of disease within prisons is not a self-limiting phenomenon, without any consequence for the whole society. On the contrary, one of the major consequences of HIV infection in prison is the spread of HIV into the community, when inmates are released, which contributes substantially to keep HIV infection endemics in some regions. The Nebraska Center for Virology press release regards a study just published by the Journal of Virology that confirms the hypothesis of a zoonotic origin of HIV infection. Researchers have identified two strains of chimpanzee-carried SIVs that can still infect human cells. These strains include the SIV ancestor of HIV-1 M – the strain responsible for the global HIV pandemic – and another ancestral strain of HIV found only among residents of Cameroon. The study aims to go beyond a research on the natural history of HIV infection,  nice but with few practical effects, because researchers claim that it "provides evidence that SIVcpz viruses (...)  still have the potential to cause a future HIV-1 like zoonotic outbreak". In other words, they argue that, as SIV crossed species in the past, it is still possible that this can happen today, posing new unpredictable threats to human health, causing new epidemics, even, they say, "a pandemic".

These two news share various elements, they both concern HIV infection and its transmission. Moreover, they are both a warning about the future, inviting not to relax too much and continuing taking HIV seriously. Finally, they are both a challenge to health communication. In the first case, it is very difficult to communicate the message that researchers aim to communicate, say, the need to distribute routinely condoms in prisons. It is easy that their study gets the opposite effect, say, causes a request to increase measures of control and surveillance. There is an everlasting denial of homosexual relations in prisons, which is particularly bizarre today, when in most countries the gay marriage is standardly accepted. Researchers implicitly, and - I suppose - unwittingly, equal homosexual relations in prison to cruel and inhuman conditions and this would be funny, if it were not outrageous.

The second study is apparently more innocuous. Luckily, today not even fascists dare any longer idiot and racist jokes on simian origins of HIV infection. Yet, researchers should be more aware that life conditions in Africa have radically changed since early 1900, when it is likely that SIV first crossed species barriers. How many butchers sell today chimpanzee's steaks?  How many people still go hunting chimpanzees? How many people live in areas where it could happen to be bitten by a chimpanzee? Brief, one cannot exclude the theoretical risk of a new HIV-1 like zoonotic outbreak, but I do doubt that it makes sense to warn seriously about such a risk.  This is clearly a way they use to emphasize the importance of their discovery, but a medical study can be significant also if it does not unravel new risks. This is a lesson not only for them but for everybody.  

Monday, July 11, 2016

Vaccines and Autism

This post is devoted to an "evergreen" of misinformation,  the well-known urban legend that links vaccines to autism. The opportunity is provided by a nice and informative post published by David Gorski, managing editor of ScienceBasedMedicine.org. Under the pretext of reviewing the movie VAXXED: From Cover-up to Catastrophe, which was in limelight a few month ago because of Robert De Niro' support, Gorski  revisits the long standing quarrel on vaccination and autism. Gorski's post is humorous and well documented, I do recommend to read it. 

Gorski sharply unravels rhetoric and suggestive mechanisms used by anti-vax  supporters. Similarly, he analyses the several, sometimes pitiful, personal reasons that have moved some medical doctors and researchers to promote a theory, not only false, but also nefarious. Yet, there is a blind spot in Gorski's approach. The hypothesis that vaccines cause autism is apparently airy-fairy, why so many people stubbornly believe in it? Are they just stupid?

There are some standard answers to this question. Yet, they capture only a part of the story and, above all, they fail to address the basic question, "why autism?".  Why, among hundreds of possible scary tales about vaccines, has autism been targeted by anti-vax people?

To find a possible answer, I suggest to give a closer look at the history of autism. The notion of "autism" is quite recent, dating back to Swiss psychiatrist, Eugen Bleuler, who first used it in early 1900 to refer to some schizophrenic symptoms. In 1940s, American psychiatrists  introduced this term to indicate children with emotional or social problems.  Autism was initially believed to be a disease chiefly caused by parents' coldness. This perspective was taken up by child psychologist Bruno Bettelheim, who coined the (infamous) expression "refrigerator mother" to mean a frigid, uncaring, mother. Bettelheim made a parallel between concentration camp survivors and children with autism and his theory put a heavy burden on families of autistic children. Bettelheim's hypothesis was then mostly rejected by the scientific community, but, as it often happens, the rejection of a theory, which was once in fashion, caused an extreme reaction in the opposite direction. Autism was conceived till 1970s as a psychological disturbance, then the pendulum swung and it became a pure biological disorder. Both approaches were clearly wrong because unilateral and inherently ideological. Today, even the existence of a condition called "autism" is put in discussion. Actually, this term is now  considered an umbrella term that gathers various conditions, which share some symptoms, but are qualitatively and etiologically very different.

If you put together these three elements, 1) families 
who "seek for revenge" - after having been put in the dock for two decades; 2) the scientific community, which now disdainfully rejects psychological theories  to uncritically espouse biological  explanations; 3) psychiatric classifications that consider autism just an umbrella term, lacking any  nosological  substance;  are you still surprised that anti-vax people have targeted autism?

In the 1950s, medical doctors "invented" a disease to label children with behavioral and developmental problems  of unknown nature, also including doubtful educational conditions. Then, they  "discovered"  the psychological aetiology  of such a disease, with parents playing  the villain role. Then, doctors changed their mind again, telling people that autism had nothing to do with psychological factors  and it depended only on genes and neurotransmitters. Finally, the same doctors are now explaining that – maybe – at the end autism could not exist at all.

 C'mon, let's be honest with ourselves.  We reap what we sow.       


Wednesday, July 6, 2016

Pandas and Mosquitoes

Who cares of mosquitoes? The world could go ahead without them, wouldn't it?  Jens Hegg, PhD candidate in the Water Resources program at the University of Idaho, disagrees. His post, published on July 1, on Plos Ecology, is a cautionary plea for thinking twice before intentionally provoking mosquito extinction. Hegg's starting point is the actual possibility that novel gene editing technology could be used to eradicate these insects. CRISPR-Cas9 technology could be used to modify mosquitoes' genome by inserting an allele detrimental to the survival. Coupled with engineered genes drives this modification could rapidly spread, eventually leading to eradicate mosquitoes worldwide.

Hegg raises many objections to this strategy. He notices that "mosquitoes are pollinators of numerous species, so their niche extends beyond simply being an annoying, painful disease vector and food for fish and bats. Can their role as pollinators be taken over quickly and easily by other species?" Ecosystems   are indeed much more complex and intertwined than we may guess and it is very difficult – if not impossible – to predict the effect of the extinction of a species. Yet, I don't want to discuss Hegg's arguments, rather to draw the reader's attention on a (minor) aspect of this story. Why – asks Hegg –  aren't ecologists, ethicists and philosophers protesting against the hypothesis of eradicating a species? Why do people - who are ready to mobilize themselves to protect unknown, exotic, species of fish - ignore trivial mosquitoes?

Some time ago, I happened to have a dinner with a colleague, a famous philosopher, strenuous supporter of animal rights. During the dinner, the conversation unavoidably went around on vegetarianism. My friend admitted that in principle he did not dislike eating beef but he refused to do it for ethical reasons. To butcher a lamb – he argued – is morally intolerable as to kill a baby. We were in summer, in a region invaded by mosquitoes and other annoying insects. I candidly asked him "But do you kill mosquitoes, don't you?". My friend waited a moment, then, he told that  "yes, I kill mosquitoes" but –  was his argument – insects are not feeling pain and emotions as animals belonging to higher species.  I still wonder how an intelligent person – as he was – could provide such a stupid answer. Who could know what a mosquito feels? How could one be as arrogant as to suppose to know what an insect could, or could not, experience?

Speaking of animals, we are all victim of the "Walt Disney' Syndrome", as I call the psychological phenomenon according to which people are sympathetic only with "nice" animals. There are some animals that have a "good press" and some others  that have not. For instance, bees are pleasant, mosquitoes are unbearable; white-tailed deer are lovely, snakes are repulsive; field mice are enjoyable, sewer rats are disgusting. Tell someone that you killed a chipmunk and he will look at you as you were Dr Mengele. Tell the same person that you killed a rat and he will congratulate. Sometimes (few) there are good reasons for our preferences,  more often they are only biases. For instance, a stray cat could transmit as many infectious diseases as a rat, but use against stray cats the same (barbarian) systems that we use to eliminate rats, and you will be probably jailed.


The "Walt Disney'' Syndrome" becomes important when we have to communicate risks connected to zoonosis. Animals are not emotionally neutral, and they are perceived positively or negatively, according to many variables, including culture and religion (e.g. one of the difficulty informing about swine flu in Muslim regions was related to the idea of impurity associated to pigs).  Are we "scientists" free from these prejudges? I doubt. Suppose someone proposes to eradicate pandas in order to fight an (hypothetical) epidemics. Are you sure that the scientific discussion would be as serene and measured as the current debate about mosquitoes?