The fight against the Zika virus has been a tough one, with previous notions about the virus being shattered on a near-daily basis. Now, today, another notion about the virus has been shattered: which strains of mosquito can carry it.

To date, global health officials have operated with the understanding that the Zika virus was only ever present in the Aedes aegypti or Aedes albopictus strains of mosquitoes. However, researchers in Brazil turned everything on its head on Thursday when they announced the "presence of the Zika virus" in Culex mosquitoes in the eastern city of Recife.

Researchers came upon this discovery by collecting 500 mosquitoes and found the presence of the virus in three pools, each containing anywhere from one to 10 mosquitoes.

However, to be clear, this discovery isn't a cause for concern yet.

Culex mosquitoes, specifically Culex quinquefasciatus mosquitoes, are the generic breed of mosquitoes that you can easily find annoying people in their homes in various parts of the world, and in the Recife metropolitan area, the population of this strain is 20 times greater than that of the Aedes Aegypti. With that in mind, one would think that the possibility of the virus being transmitted would be that much greater. However, the findings came attached with a word of caution, saying, "the obtained data will require additional studies in order to assess the potential participation of Culex in the spread of Zika and its role in the epidemic."

Simply put, for researchers, the presence of the virus in the mosquitoes doesn't automatically mean they can transmit it.

In fact, a U.S. study published earlier this week in the journal Emerging Infection Diseases  determined that a another type of Culez mosquito was incapable of transmitting the Zika virus in a lab setting.

So, what does this mean in the end? Nothing, so far. There is no evidence that Culex quinquefasciatus can transmit the virus, and a study has already shown that Culex pipiens shows no indication of being able to transmit the virus. So, unless this study gets replicated, it's hard to assess its possible implications.

Of course, things can change in a heartbeat, as Zika has clearly proven in the past few weeks. It wasn't until recently that we learned that Zika can be transmitted from females to males, and now, U.S. health officials are grappling with the possibility of the virus being transmitted by means other than a mosquito bite, sexual intercourse or mother-to-child.

However, in the meantime, Aedes still stands as the primary source of Zika outbreaks.