See https://ajph.aphapublications.org/doi/abs/10.2105/AJPH.40.11.1405 for a contemporaneous 1950 description of how autochthonous malaria was eliminated in the continental US. A key ingredient was development and implementation of a surveillance case definition, with case report forms forwarded to a central authority (at CDC) for review against the case definition. This allowed public health workers to ignore a very large fraction of the case reports, which had a low probability of actually being malaria, and to focus their efforts where there actually was continuing transmission.

Also, don't underplay the importance of increases in the prevalence of air conditioning and of effective screens in reducing the transmission of mosquito-borne illnesses. During my time in Florida public health (1990-2012) we saw a recurring pattern that transmission of such illnesses (Saint Louis Encephalitis, West Nile Virus, Zika, etc as well as malaria) happened among people who spent time in the evening sitting outside their modest homes to get cool, because of no or limited air conditioning. Sleeping outside because of lack of housing is also an obvious risk factor. So you need not just the right vector etc but also opportunities for people to be exposed to infected mosquitoes.

Expand full comment

Thank you. As a gardener it is also a timely reminder to check for standing water.

Expand full comment

An interesting read. I live in the Northeast and I noticed this year a flock of chimney sweeps zooming around this year and the mosquito population along with other insects seems to be minimal in our yard, which we do not treat with any chemicals. An interesting observation on my part, as unscientific as it is.

Expand full comment

Looks to me like you and the major media missed something really big, and a possible reason for these malaria cases. You are smart, so is this something you did not think of or is it something that cannot be discussed?

"However, Anopheles mosquito vectors, found throughout many regions of the country, are capable of transmitting malaria if they feed on a malaria-infected person." This quote is on this CDC webpage from June 26: https://emergency.cdc.gov/han/2023/han00494.asp

There are huge numbers of people coming over the border all the time now from Mexico - a nation that has some Malaria. These illegal and legal immigrants come from all over the world and they could have malaria. So an malaria infected immigrant gets bit in Texas or Florida by a mosquito, and then that same mosquito transmits the disease to an American who never left the country.

This shows that it's possible for a person to get malaria without ever traveling outside the U.S.

Any comments? Let's see.

Expand full comment

There is something else regarding mosquitoes and the diseases they spread which is not mentioned in this article. That's the existence of genetically engineered mosquitoes in the U.S.. Have they actually been effective in reducing disease in the U.S.? Some say yes, some say no. But it is a large scale experiment which could have a bad result, and cannot be easily reversed if it does go bad.

Expand full comment

Nonsense. If it fails, then at worst we are back to where we started. In the meantime it saves lives, buys us time to develop vaccines, therapeutics, better bug repellant, add insect screens to building windows, and educate the public on getting rid of standing water.

Expand full comment

Thanks for your comments. I searched a little harder to see if these GE mosquitos have actually done any good against "dengue fever, Zika, chikungunya and other deadly viral diseases" as the company says certain mosquitoes cause. I only did a quick search on the company website but found nothing there that says diseases were actually reduced by GM mosquitoes. They have been releasing these GE mosquitoes in Brazil since 2011. And they had this to say about Brazil:I " In 2022, Brazil recorded 1,016 confirmed deaths from dengue, 400% higher than the previous year, and the highest registered in one year. The number of cases of dengue in 2022 was around 1.4 million – 164% higher than in 2021, according to the Ministry of Health. " So about 12 years after they started with the GM mosquitos, things are going the wrong direction .https://www.oxitec.com/brazil

They are now working on a GE mosquito for malaria.

This webpage goes into the pros and cons of GE mosquitos. It's a poor article because the authors failed to record the day they published it.https://www.mosquitomagnet.com/articles/gmo-mosquitoes-pros-cons

One of the biggest cons:

Concerns that the GMO mosquitoes may mutate into a stronger mosquito that can reproduce, which poses a whole new threat.

Expand full comment

Again - that's not really a "whole new threat". It's exactly back to the original one. I'm not really sure how you define "stronger" - adapted to get around whatever method was used to reduce their population? Well, sure. But if that's not something that was being done before - so what? It still buys time. There's no significant downside to releasing GMO mosquitoes in high risk areas, there appear to be immediate reductions in vector borne disease when they're used, and the only people who seem to be dead-set against GMO mosquitoes seem to be convinced that all GMO is categorically bad.

And the mounting evidence is that it *does* work.


Expand full comment

Again, apparently not a single scientific study that shows the diseases these mosquitos carry was reduced in the areas the GM mosquitoes were used, after 12 years of use in Brazil. Same thing in the U.S. - no science showing these diseases were reduced after a few years of use in the Florida keys. Ok, so there are less mosquitoes - but that's not really the goal.

There is one reason given here for the big increases in the diseases in Brazil - increased resistance to in insecticides by the mosquitoes.

Now here's a really weird thing I'd like to know more about. Why are they going to do this in California? What diseases do we have here caused by that mosquito bite? How many people get sick with those diseases in California? Why is that not in any articles we can find? Maybe the answer is out there, but just speculating here - the number of people affected by the diseases spread by these mosquitoes in California is very tiny - so tiny that it makes it hard to justify the expense of reducing the mosquito population this way.

Here's what is suspicious from the Wired article: "Still, there’s one big question left unanswered: whether releasing these mosquitoes actually reduces disease transmission. Oxitec hasn’t yet conducted studies on the public health impact of its mosquitoes."

Why have they not done the studies?

What's actually much more likely (to me) is this - they and others have done these studies and the results were not good. So they just keep quiet about it and don't publish the studies. The data on how many cases of these diseases are in the Florida Keys is likely somewhere to be found. So it would not be hard to look at those numbers as see if there was any reduction in the diseases. Why has public health not done this? Governments are paying for these GM mosquitoes. Don't they have a responsibility to see if their programs are actually working?

It would be very easy to design a study - just count the number of disease cases in the Florida keys, then stop the program for a year or two and see if the case numbers went up or down.

Thanks again for your comments. So far nobody else has commented on my post, which points out that malaria infected people could be responsible for the cases in Texas and Florida which were the first cases in some time where a person did not have to travel outside the country to get malaria.

Expand full comment

Nobody is disputing the human -> mosquito -> human transmission cycle.

I don't think there's any reason to think that people crossing the border is a significant driver. Mosquitoes have no trouble crossing borders, and there are plenty of people *near* the border, but that's nothing new.

What *is* new is the favorable conditions for large populations of the right type of mosquito, thanks to global warming. That also makes it harder to tease out whether interventions to reduce mosquito populations are effective.

Expand full comment

We should look at the number of travelers that visit these endemic areas as well. Since the incubation for malaria range from 7 to 30 days, one could return without knowing.

Expand full comment

So, this is happening with out follow up studies, really? Keep in mind this started in Florida April, 2021. Need to collect data, analyse and prepare reports and this takes time, even to run this study period.


Here's another method to control mosquitoes.


In the meantime, learn about this very complex parasitic life cycle.



So, however we look at this, we are really talking about controling the population rather than eliminating it. We should have learned this by now.

Expand full comment

From your first link from the Oxitec company: "In recent years the Florida Keys have seen locally transmitted cases of dengue and travel-related cases of Zika." Ok, how many cases of Dengue were locally transmitted in the Florida Keys? Why do they avoid writing that number down? It could be the number is tiny and thus it doesn't justify this expensive program to reduce the mosquito population this way. If it was a big problem, I would think they would give us the number as it would help sell their products to more areas. I recall a few years ago trying to get that number before the program started in Florida. I either did not get the number or it was tiny. See if you can get the annual number of Dengue cases for the years before the program stared in Florida. And then see if you can get the number for the number of cases since the program started. What if there are more cases now after this program started? That's what's happened in Brazil. After 12 years of reducing the misquote population this way, the Dengue numbers hit an all time high.

The article I found said Oxitec has not done any studies to see if its products have reduced any diseases. But it's not Oxitec's job to see if there are less diseases after their programs are started. That's the job of public health. Government pays for these programs, although I suspect local government get federal grants for them. It's simply wrong to assume that these Oxitec programs are working without any direct evidence they do. Search the Oxitec website like I did. Do you see any science or any statements of Oxitec saying they have reduced the prevalence of any disease anywhere? I did not find any.

Yes, Oxitec has done studies that show they can, with continue use, reduce the number of these bad mosquitos. If it's actually working to reduce diseases then it's better than spraying insecticide which kills other insects, as long as there no negative consequences like making stronger mosquitoes. But I have not found evidence these programs reduce disease. Maybe it's out there, but I can't find it.

So now public health intends to do these programs in California. Let's see how many cases of these disease are locally caused in that state. Can somebody do that?

There have been many environmentalist groups opposed to these GE mosquitos since the beginning more than 12years ago. One fear is that they might produce genetic changes that could make the problem worse.


Expand full comment

Regarding Silent Spring, I'm curious how many know about the flaws with it? https://www.thenewatlantis.com/publications/the-truth-about-ddt-and-silent-spring

We should not accept living with malaria or other similar diseases again if we have the means of eradicating and limiting them, without significant unintended consequences.

Expand full comment

About the newatlantis

"The journal is editorially reviewed, however is not peer-reviewed on scientific topics."

Indeed, many of the premises were bias, not science based.


For example, bird population, especially Birds of Prey, began making a comeback after DDT was banned. Along with the Endangered Species Act and conservation, The Bald Eagle is now found in area that lost its population. The problem was not DDT but actually DDE.


I could go on but the real demise of DDT was the rise of pesticide resistance in mosquitoes.

Expand full comment

Agree that resistance to DDT was the final nail, but the article I linked does discuss the real effect on birds of pray through thinning of their eggs. What else in there was bias rather than scientific? As far as I can tell, Silent Spring still had flaws which are generally not acknowledged and the benefits of DDT up to the time of Silent Spring still far outweighed the negatives. In my opinion, it seems like a cautionary tale about weighing the relative costs, both in terms of widespread use of DDT and widespread banning of DDT.

Expand full comment

Apologies for off topic, but this is hot off the press from Oxford University, and great news for those interested in getting a Novavax booster this fall. Punchline: Single shot of Novavax (for 12-16 year olds who had Pfizer 8 weeks earlier) led to fewer breakthrough infections and 8 months of protection. Fingers crossed everyone is allowed access to the Novavax booster this fall. Link here:


Expand full comment

Here's the detailed scientific article published in the Journal of Infection. Important to note that the study was conducted using the vaccines from 2022, yet presumably the findings hold for the next crop of monovalent XBB.1.5 boosters being released this fall. Also, study was on teenagers, not adults. It would be nice to know how much better the Novavax vaccine is at preventing breakthrough infections vs Pfizer and for how long - I wasn't able to easily find this in all the data and charts.


Expand full comment

Where in Florida were the 4 cases? Curious because I live in Orlando, FL

Expand full comment

Sarasota County. They tested mosquitoes there and 3 have come up positive for Malaria. So far, none of the Texas ones have. https://www.usnews.com/news/health-news/articles/2023-06-30/mosquitoes-test-positive-for-malaria-in-florida

Expand full comment

I believe that figure is now up to 7 that been reported.

Expand full comment

I did see the case number just went up to 6 in Florida as well:/ I can’t find anything on the increased positive mosquito count but I know they were testing 100 of them.

Expand full comment

Likely these numbers will increase over time.

Expand full comment

5 cases. that's not many. Could quickly escalate to a major disaster. But I bet Bill Gates is on it with a new vaccine and save us, like he did from covid. Trust the science!

Expand full comment

Remember when there were only 12 cases of Covid in the US?

If a disease is endemic somewhere, in a rapidly warming world where all life forms are desperately moving to the small number of remaining habitable spots, it will eventually be endemic everywhere. We are entering an era of pandemics and paninvasives.

Expand full comment

Top of the news from WHO today https://www.who.int/news/item/05-07-2023-18-million-doses-of-first-ever-malaria-vaccine-allocated-to-12-african-countries-for-2023-2025--gavi--who-and-unicef

So yeah, Gates and others have been on the job of developing this particular vaccine for over two decades https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7227679/

Expand full comment

Like HIV, the parasite has a very complex life cycle that makes developing therapeutics and vaccines an arduous task.

Expand full comment