Nursing Homes aka Antibiotic Saunas

One of the aspects of antibiotic resistance that will prove difficult to solve, even with a presidential national action plan, is the issue of nursing homes and long term acute care hospitals (LTACs) These facilities are populated by many chronically ill individuals, some of who are chronically critically ill and continually on ventilators and hemodialysis. Many have long term intravenous lines and urinary catheters in place. In these settings infection control is sparse or non-existent and these individuals contract infection after infection as the residents of such facilities rotate in and out of hospitals continuously. 

Antibiotic stewardship, rapidly becoming the lynchpin in the defense against resistance, is a joke at many nursing homes. I have heard first hand anecdotes of ordinary nurses starting antibiotics without consultation for cloudy urine, for example. In essence, such settings literally marinate bacteria in antibiotics spawning super bugs.

The danger is magnified when these patients are transferred to hospitals--often to ICUs--where the superbug they harbor finds new frontiers to conquer. Also, people visit nursing home and LTAC patients and they themselves can contract infections from this visit (this may be behind some of the community-onset C.diff cases). 

When solutions to the antibiotic resistance plague are proposed they will only gain traction to the extent that they address all settings, particularly ones in which microorganisms literally bathe in inappropriately prescribed antibiotics. To that end, I believe that hospitals should find a mechanism for their infectious disease physicians to have some oversight and consultative roles at the nursing homes and LTACs that frequently utilize their hospital for acute hospitalizations--such as has been piloted by the VA. 

HIV in Indiana: Virus Always Remains a Serious Threat

This week Indiana Governor Mike Pence declared a public health emergency in Scott County because of a surge of 79 HIV infections amongst those who inject drugs since December 2014. 

Though HIV is traditionally considered a risk for injection drug users, in recent years infections in this demographic group have declined from a peak of 35,000 infections in the 1980s to just around 3000 in 2013. The tremendous decline can be attributed to better testing coupled to wider availability of clean needles via pharmacies or formal needle-exchanges. That 37% of injection drug users infected with HIV are unaware of their diagnosis (vs. just 14% in the whole HIV positive population) is a major factor that can facilitate the explosive spread of this virus as has happened in Indiana. 

However, the uptake and availability of these services is not uniform and some users failing to avail themselves of these preventative measures. Indiana is one such state where needle-exchanges are unable to operate legally. Consequently, as part of the public health emergency, Governor Pence has allowed the operation of these vital resources in Scott County as an emergency measure. (Thankfully, in Pittsburgh we have a robust needle exchange, Prevention Point Pittsburgh, on whose board I serve). 

The lesson to be drawn from Indiana's experience is that infectious diseases can exploit complacency and imperfect defenses. This illustrates that when it comes to infectious diseases all defenses--including needle exchanges for those infections spread via injection drug use--most be in continual operation.

Dissecting Tuberculosis in the US

Today the CDC released the latest numbers on tuberculosis in the US and it is all good news with a couple of caveats.

Overall, there's been a 2.2% decline in tuberculosis in the US with just 9412 cases reported in 2014. This translates to a rate of 3 cases per 100,000 people which is extremely low but not yet at the goal of 1 case per 1,000,000. Indeed, recent news stories have shown that the risk of tuberculosis still exists with an active case diagnosed in a Pittsburgh school; a similar incident in Kansas caused 27 students becoming skin test positive, indicating they contracted latent TB.

When one dissects the rate of 3 cases per 100,000 there are several important and ominous findings: 

• The rate of tuberculosis is 13.4 times higher in those foreign born when compared to those born in the US; 66.5% of cases are in this group
• Asians are the ethnic group with the highest burden of cases in the US
• Hawaii is the state with the highest rate of tuberculosis in the US
• California, Florida, New York, and Texas account for 50.9% of all US cases in 2014
• 6.3% are HIV-positive
• Just 1.3% of cases (in 2013) were multi-drug resistant

Interpreting these numbers, it becomes clear that tuberculosis is a waning problem in the US when looked at in aggregate. However, looking at the data in all its granularity it becomes clear that the final push for tuberculosis control will be in finding foreign-borne individuals with latent tuberculosis--immigrants are screened for active tuberculosis via culture and chest x-ray in their home country--and placing them on treatment to prevent reactivation. Such an effort is daunting as many of the individuals in these communities are not readily available to public health and medical officials, but placing them on treatment is the means to eliminate tuberculosis from the US. 

Cyanide in White House Mail & The Need for Eternal Vigilance

I come from Pittsburgh so I am particularly attuned to mentions of cyanide in the press since we've recently had one prominent researcher murder his physician wife using the substance as well as another researcher use it to commit suicide.

News that The White House received a cyanide-laden piece of mail should not, however, lead to widespread panic as cyanide, like ricin (which has also been concealed in recent mailings to several government officials), is better thought of as a poisoner's tool rather than a mass casualty inducing substance (though it was used in gas form in Germany's WWII concentration camps). I often describe such substances as weapons of mass hysteria rather than mass destruction. In the context of mail, the intended mode of exposure would be via the skin which is less effective than via inhalation or ingestion. It appears that this attack originated from someone known to government officials.

Cyanide is a simple substance that is relatively easy to obtain and is a well-known component of house fire smoke as it is formed from the burning of carpet. Cyanide's deadly characteristics come from its ability to block the ability of cell's to utilize oxygen to make energy. This property essentially halts all cellular activity and ultimately leads to death. There are antidotes to this poison, but they must be administered quite rapidly to have any effect. 

An interesting aspect of the nefarious use of cyanide is the past effort (which thankfully never came to fruition) by Al Qaeda to develop a device to disperse the cyanide gas in a manner capable of causing mass casualty in the New York City Subway. Finding this device, named the "mubtakkar", and uncovering the plot to use it became a major priority for the Bush Administration. 

Anytime a biologically active substance is used in the initiation of force it is a major cause for concern and should reinforce in the minds of all how easy it is use these substances as weapons. While 14 years have passed since the anthrax attacks, cyanide and ricin biocrimes have been occurring with increased frequency, highlighting the low barrier to their acquisition. Preparing for such events by heightening awareness, improving diagnostic capability, and developing effective countermeasures must remain a priority. 

Could Infectious Disease Physicians Replace Psychiatrists?

Infectious disease physicians always like to imagine that every type of pathology is due to an infection. Cancer-causing viruses and ulcer-inducing bacteria are cases that illustrate the ubiquity of microbes as etiologic agents for conditions long thought to be non-infectious. Psychiatric illnesses have, thus far, not demonstrated a definitive link to infection. A growing body of fascinating new research, however, is beginning to change that.

Many science and evolutionary biology enthusiasts are familiar with the parasitic infection toxoplasmosis, an organism that often has pregnant woman avoiding kitty litter boxes. It is well established that toxoplasmosis infections in the brain of rodents change their behavior by attracting them to a substance they naturally avoid, cat urine. Such a behavior change renders them much more likely to be devoured by a feline allowing the Toxoplasma parasite to reach its beloved primary host.

Could this infection also influence human behaviors?

Perhaps it is behind the plague of humans who display a zombie-like obsession with endlessly watching cat videos on the internet? 

About a quarter of humans are infected with toxoplasmosis and it is generally considered to not be a major problem except for in certain circumstances such as pregnancy, HIV, or transplantation. What really is striking is the fact that those with certain mental conditions are harbor the organism at a higher rate than the general public. For example, schizophrenics are 2.7 times more likely to be antibody positive than members of the general public. Associations have also been noted for generalized anxiety disorder and bipolar disorders.

Correlation is not causation and an infection cannot override the volitional nature of human consciousness. However many questions remain to be answered such as: is toxoplasmosis a surrogate marker for something else that lies behind these conditions, if the organism plays a causative role is it the infection or the post-infection immune response that is operative, would treatment change the course of illness? 

It is also important to remember that not every case shows this association and multifactorial explanations for psychiatric illnesses are the norm. 

Nevertheless that an infectious disease may play a partial role in some of these illnesses would represent an important breakthrough that could lead to new means of both prevention and treatment.