Dengue Fever: Back in the USA?

There has recently been an uptick in media reports focused on the threat of the mosquito-borne dengue virus in the US. The latest is an article, in which I am quoted, that details the mosquito control efforts of California, a state where no cases have been detected. 

Until this year, local spread of dengue was know to have occurred in Texas (chiefly along the border with Mexico), Florida, and Hawaii, the details of which can be found in a paper my colleagues and I wrote on the topic. This year, however, in addition to the uncovering of evidence of local spread in Houston, a locally-acquired case was detected in New York.

The key thing to remember with respect to dengue is that since the Aedes mosquito is present over a large swath of the US and there are a continual stream of potentially infected travelers--who may be asymptomatic--it is not surprising to find instances of local spread of dengue occurring in the US. In fact, serosurveys along the Texas-Mexico border have shown up to 40% of individuals exhibit evidence of exposure to dengue. 

Clinicians and public health officials should keep these facts in mind when investigating or treating unexplained febrile illnesses.

Cervical Cancer: Hopefully a Relic of the Past

Last night on an episode of Showtime's Masters of Sex, a drama focused on the research of Dr. William Masters and Virginia Johnson, the early work to encourage uptake of the now ubiquitous pap smear was portrayed. This test, developed by Dr. Georgios Papanikolaou, has proved to be essential in early detection of cervical cancer, whose cause is chiefly the human papilloma virus (HPV). 

In the episode a physician--played by Julianne Nicholson--is an early promoter of the procedure who is, herself, dying from cervical cancer. 

It is largely due to the early detection of cervical cancer via routine pap smears that such deaths are almost a relic of the past in the US. However, approximately 4000 deaths per year in the US are attributed to cervical cancer. 

Vaccines against HPV, as a supplement to routine pap screening, offer the promise of further decreasing the burden of cervical cancer. Currently, two vaccines are available: Merck's Gardasil and GSK's Cervarix. Both vaccines protect against the most common cancer causing strains of HPV while Gardasil offers additional protection against strains of HPV that cause genital warts. The vaccines likely offer protection against other HPV-caused cancers (vulva, vagina, anus, oropharyngeal) and are now part of routine childhood immunization schedules after much political wrangling (see Three Shots at Prevention: The HPV Vaccine and the Politics of Medicine's Simple Solution). 

Chikungunya Virus in St. Martin

The Caribbean island of St. Martin is reporting two cases of the mosquito-borne viral illness Chikungunya with 34 additional probable or suspect cases. This is an important story because, to date, this virus had not been found in the Caribbean. Chikungunya is infamous for causing a large outbreak on the Reunion Islands in 2006 (after importation from Kenya) that went on to spread to various nations of Asia and Europe.

This virus is transmitted by the Aedes mosquito which is widely distributed in both the Caribbean and the US. It is also the vector for dengue and yellow fever. While 2 cases of chikungunya might represent recognition of travelers infected elsewhere--as has been reported in the US--34 cases are likely the result of autochthonous (local) transmission. 

As such, these cases in St. Martin may represent the tip of the iceberg. It would not be surprising to find more cases in other Caribbean islands or even on the US mainland were Aedes mosquitoes abound and are readily available to bite viremic travelers.

Antibiotic Resistance: Back to the Future

In today's Pittsburgh Tribune Review is an article by Mike Wereschagin detailing the public health emergency posed by antimicrobial resistance. I was interviewed (alongside the leading voice on this topic, Dr. Brad Spellberg of UCLA!) for this important article and made a few points that included:

• Alexander Fleming prophetically warned of this trend in the 1940s
• In my own career, I have had to "treat" totally drug resistant infections and have seen patients succumb to their infections
• The need to move from non-specific therapies such as broad spectrum antibiotics to targeted therapies such as bacteriophages and antibodies (which were the mainstay of treatment prior to the discovery of antimicrobials, see Arrowsmith)
• Brian Potoski, a stellar infectious disease pharmacist and my colleague, makes the point about the danger of using antimicrobials for common viral infections (which is incorrectly done the majority of the time)

Adding to the information contained in this article, is a small piece I wrote detailing the Lancet Infectious Diseases report on the issue and their recommendations, which include exploring the "age-old" phage therapy."

Severe ARDS Centers

An important research study focused on the geographic characteristics of severe ARDS centers undertaken by UPMC's David Wallace (who was one of my CCM co-fellows) and colleagues is to be presented at the annual SCCM meeting in abstract form.

Wallace's study looks at the locations of hospitals equipped to care for individuals with severe ARDS based on variables such as their annual mechanical ventilation volume and capacity for ECMO. What Wallace found was that between 88 and 99.7% of the US population has access (via ground or helicopter) to a severe ARDS center within 2 hours.

This study provides essential underpinning to construct a national system of severe ARDS centers--similar to trauma, cardiac, stroke, transplant, and burn centers--which could prove crucial during an outbreak of a severe respiratory infection such as influenza, SARS, MERS, or an as yet emerged pathogen.

A few years ago, my colleagues and I developed a conceptual model to construct such a system. It is with research such as conducted by Dr. Wallace that such a system may, one day, become reality.