They keep us awake at night, playing in the walls or attic. They travel on subways and play in trash. Urban rats are very commonly found, but not much is known about the potential threat they pose to public health. In the journal Frontiers in Public Health, a trio of scientists issued recommendations for how to capture and track rats. The method was developed in New York City.
The recommended method to track rats starts with setting out cages with pheromones to lure them in. The captured rats are anesthetized, fluid samples are taken, fur parasites taken from fur, and microchipped between the shoulders. The best place to trap rats is in a crowded place where the sample collection can be done discretely. After release, the rats are drawn back the same way to weigh them and see if pathogen levels change over time. Sensors will have to be sanitized, as infected and uninfected rats will frequent the same locations.
There is not much information about the pathogens rats carry. Rodents don’t carry nearly as many diseases or deaths as mosquitoes do. They do transmit fevers, meningitis, and plague. Exposure to these diseases are through bites, scratches, contact with feces, urine, and fleas. More infections may be spread by rats that have not been discovered yet. Pathogens carried by rodents have great potential to make people sick, but the cases may be rarely diagnosed as the source may be unknown. It is hard to estimate the extent to which rat-carried diseases cause sickness. Rats may be “mixing bowls”, picking up all kinds of pathogens like a sponge, as breeding grounds for pathogen interaction.
A 2014 paper on New York City rats states that the diversity of microbes they carry needs to be tracked through surveillance and spreading awareness of disease risks with rodent infestations. City dwellers should not live in fear of rats, but get ahead of the problem by surveying rats and tracking their travel patterns. The NYC Department of Health and Mental Hygiene has a rat surveillance program with a 2015 budget of $2.9 million and 170 people on staff. It can be expensive and labor intensive for cities to launch rat programs. The cost of diagnostic testing alone can add up.
Joseph, Andrew. “Are NYC rats disease ‘sponges’? Scientists want to track them to find out.” Health. STAT, 14 Jul 2016. Web. 19 Jul 2016.