With thousands possibly exposed to Mumps at a national cheerleading event in Dallas, Texas 2 weeks ago, making sure children are up to date on their vaccinations has never been more critical. People usually wonder why these events occur, discrediting herd immunity and vaccine efficacy. However, nothing is 100% in medicine. Even if everyone gets vaccinated, not everyone will respond and develop immunity. One or two may remain susceptible. Also, not everyone can get vaccinated as some can have true allergy to some vaccine components while some are immunecompromised to a point that vaccination is contraindicated. Therefore, these small number of people are dependent on the rest of the population being immunized to be protected from the disease. However, if there are other people not immune, like free riders, the disease can more easily spread. This gif beautifully illustrates this.
In 2014, tuberculosis overtook HIV as the number one infectious disease killer in the world and continues to remain at the top. In the United States, there were 9,287 persons diagnosed with active TB in 2016. The CDC estimates that of the cases with genotype data, only 14% are attributable to recent transmission. That means majority are reactivation from latent infection. Prompt identification and treatment of active TB is necessary but insufficient by epidemiologic modeling to achieve the goal of TB elimination. Identifying and treating persons with latent TB is needed. Thus, the United States Preventive Services Task Force issued recommendation to screen patients with risk factors (such as in general being foreign-born) in September 2016.