Think TB. Stop TB.

Too many times I have seen doctors miss the diagnosis of tuberculosis (TB) despite seeing an apical cavitary lesion on the patient’s radiograph. Delayed diagnosis in this case is not only unfortunate for the patient. It is also a public health issue as more people are unnecessarily exposed to a contagious disease that could have been prevented by earlier proper diagnosis. Health departments can only do so much if private clinicians fail to consider TB in their differentials.  Having not been diagnosed properly, their patients with the airborne disease continue to spread it. It is true that unlike in many other countries, TB is not endemic in the US. However, that doesn’t mean we can forget about it. Doing so is one reason why TB continues to sneak up on us. Every doctor, even those in the private sector, has a public health responsibility to have TB in their differentials as appropriate.

Preventing HIV

There may not be a vaccine (yet) for HIV. However, one can take a medication to prevent having HIV, especially if one is at risk for acquiring it (such as persons engaging in high-risk behavior or if they have partners who are HIV-positive). This is called Preexposure Prophylaxis (in short, PrEP). This is in contrast to Postexposure prophylaxis (in short, PEP), in which the medications are taken after a person has been exposed to HIV already. The US Public Health Service actually released a clinical practice guideline on PrEP in 2014. It urges clinicians to consider offering PrEP as an HIV prevention option to their patients at substantial risk of acquiring HIV infection. However, despite these, PrEP is still not very commonly employed. One hurdle may be that many clinicians are not comfortable with prescribing anti-retroviral medications. Also, even after getting a prescription for Truvada (the medication used to prevent HIV in PrEP), the patient still has to navigate the health system in order to get it, which includes asking his/her health insurance provider to cover the medication and coordinating with other patient assistance programs and deal with the co-pays, deductibles, and prior-authorization requirements. Luckily, in Austin, we have the Austin PrEP Access Project that helps people interested in PrEP in navigating the health system. More information can be found at http://www.austinprepaccessproject.com.

The Problem with Screening Everyone

In 2006, CDC recommended that patients in all health-care settings be tested for HIV. In 2013, the USPSTF followed suit and advised HIV testing for persons 15 to 65 years. However, as basic statistics would dictate, testing low risk population will lead to increased false positivity in test results. The increasing sensitivity of the fourth generation HIV tests can even worsen this. As the HIV testing recommendation above is getting applied by more and more health institutions and public health entities, the problem of high false positivity in low risk population arises. It is a very serious matter for a patient getting told what his/her HIV screening result is (it can be very anxiety-provoking). It is also a serious matter for public health as each positive HIV test can mean new case to investigate for Disease Intervention Specialists (DIS). It is therefore very important that providers explain to the patient the concept of positive predictive value of the test in the setting of low prevalence if the patient is of low risk of having HIV.

Prophylactic Treatment for Syphilis

Due to continued increase in cases of syphilis, some health departments have started implementing mass treatment for syphilis. This involves the prophylactic intramuscular administration of penicillin G (or if penicillin-allergic, be given doxycyline tablet for 2 weeks) to individuals with high risk sexual behaviors (having more than one sex partner in the last 60 days or having anonymous sex). This is done in the hopes of preventing the onset of incubating syphilis and its subsequent transmission. Opponents of this intervention cite possible behavioral consequences (individuals being more likely to engage in high risk behaviors after prophylaxis as it can make them feel “invincible”) can lead to worse outcomes. However, the target population for this intervention are already engaging in high risk behaviors. Therefore, there should be not much of a change there. Another point they raise is that some programs who did the intervention ended up with rate rebound (after the intervention, the number of cases was higher than expected). However, there are other programs who had success with mass treatment of syphilis. This just argues that the intervention should not be done routinely and that each program’s situation should be analysed first to see where the main transmission of the disease occurs so as to determine whether it can benefit from the intervention. One more issue is the risk of the development of resistance to penicillin. Then again, penicillin has been used for syphilis for decades now and and it is still the best drug for it (no development of resistance has really occurred).

Technology & Syphilis

Technological developments have brought us many good things. The invention of vaccines, for example, have led to the elimination of certain diseases (those diseases coming back associated with the non-use of vaccines is for another post). But one would not expect technology to be associated with the increase in the prevalence of a disease. This is actually the case with syphilis and social media apps such as Grindr and Adam4Adam. The latter has made it easier to have anonymous hook-ups, which is thought to contribute to the prevalence of syphilis, at least in certain areas. The association between the two has been undeniable such that the use of social media apps is now considered a risk factor in having syphilis or other sexually transmitted diseases by some health care providers.