Note: Dr. Elizabeth Lee Vliet is a member of the Association of American Physicians and Surgeons, AAPS.

Since 2005, Americans have been warned about microscopic border crossers carried in with refugees and illegal immigrants, bringing diseases previously eradicated or rarely seen here. When not simply ignored by media and health officials, physicians and others sounding the alarm have been attacked as xenophobes.

Now we're seeing these prescient predictions come true, most prominently in Germany, since 2015 when Angela Merkel began allowing more than 2 million migrants from Africa, Asia and the Middle East to flood into her country.

U.S. and German citizens are put at significant risk by the politically correct acceptance of unscreened immigrants from countries with a high prevalence of infectious diseases, many difficult or impossible to treat. Yet authorities in both countries have failed to fully inform the public of the dangers.

According to the July 2017 Infectious Disease Epidemiology Annual Report by the Robert Koch Institute in Berlin, Germany has seen a surge in chicken pox, cholera, dengue fever, tuberculosis, leprosy, measles, malaria, meningococcal diseases, hemorrhagic fevers, hepatitis, HIV/AIDS, paratyphoid, rubella, shigellosis, syphilis, typhus, toxoplasmosis, tularemia, trichinellosis, whooping cough, and many fungal and parasitic infections. Here are a few striking examples:

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Measles is up more than 450 percent. Hepatitis B is up 300 percent. Scabies escalated nearly 3,000 percent. HIV/AIDS increased 30 percent. Tuberculosis (TB) is at least 30 percent higher – but German and U.S. physicians suspect that the incidence of TB is actually far higher than reported, and is being downplayed to avoid causing public outrage over the influx of immigrants. In Germany, more than 40 percent of TB cases are multi-drug resistant TB (MDR-TB).Dengue fever is up over 25 percent just from 2014.

A similar pattern has emerged in the U.S. since the massive increase in illegal border crossers and refugees beginning in 2010.

As in the U.S., many hundreds of thousands of migrants "disappear" into cities and towns across Germany, without a health screening. There is no way to monitor them for disease or to ensure adequate treatment. Citizens are exposed without their knowledge; risks are especially serious for children and the elderly.

In a briefing to the Arizona Senate in 2016, experts reported that the U.S. is suffering near "pandemic medical issues" due to the continuous influx of illegal aliens and refugees from countries where infectious diseases are widespread. As of 2016, two states were in the Catastrophic Phase and another 13 were in the Critical Phase of public health impact from these infectious diseases. Arizona was No. 9 of 13 states in the Critical Phase but was expected to move into the Catastrophic Phase by fall of 2016 as a result of people who are latent carriers of disease or who entered the country during the incubation period for a disease. We were unable to learn the current status from personal calls to Arizona county and state officials.

TB is one of the most serious threats. Latent TB can remain dormant for years, even decades. It is alarming that 18 percent of refugees in Arizona arrive with latent TB, while in the general Arizona population the incidence was only 4 percent. Multidrug resistant TB (MDR-TB), common in migrants, may cost more than $400,000 per patient, compared with $20,000 for the drug-responsive TB that has been predominant in U.S.-born patients. Treatment of MDR-TB has serious side effects, with no guarantee of success.

U.S. taxpayers pay this cost. In addition, all who might have been exposed to an active case must be screened, followed and possibly treated.

Even healthy immigrants burden the system with social costs, such as housing, education and food stamps – costs borne by taxpaying workers whose own wages are depressed by competition from a glut of low-paid foreigners. Illegal immigrants are estimated to cost U.S. taxpayers $17 billion per year. That $17 billion is in addition to the costs for those allowed here legally under "refugee" status, for which we do not have reliable public estimates.

Liberal and progressive politicians like to say, "America is the land of immigrants." In the past, this meant legal immigrants who follow our screening procedures for illness and other laws and who are coming to America to be part of our culture.

Medical screening was one of the core purposes of the Ellis Island immigration center in New York. New arrivals were examined, quarantined if needed, or sent back to their country of origin if they posed a risk to Americans.

To protect the health and safety of American citizens, we must reinstate our prior customary medical screening as outlined on our own Centers for Disease Control and Prevention (CDC) website.

For national security and medical concerns, President Trump is correct to enforce our immigration laws, with careful vetting of those seeking to come to America to live and work.