'Most of the mosquitoes that transmit tropical diseases are already in Andalucía'

Dr Francisco Javier Membrillo (Seville, 1980) is the head of infectious diseases at the Hospital Gómez Ulla in Madrid and vice-president of the Spanish society of infectious diseases and clinical microbiology (SEIMC), which is holding its 28th national conference in Malaga from 22 to 24 May.

The event has brought together 2,000 specialists in the field and will address medical trends such as the challenges posed by emerging tropical viruses, from West Nile virus to dengue and chikungunya, resistance to antibiotics and the increase in sexually transmitted infections (STIs).

Among other demands, Membrillo is calling for the creation of a medical specialty for infectious diseases within the MIR (medical residency training) system, as well as the presence of clinical microbiology laboratories in every hospital, operating 24 hours a day, seven days a week. He argues this is crucial due to their decisive role in reducing mortality, especially in serious infections such as sepsis.

In the following interview he gave for SUR, he reviews all the challenges in his speciality.

The Nile virus has caused around a dozen deaths in Andalucía. Where are we now in the fight against this disease?

-Well, we are in a complicated moment, because we are seeing more cases every year. We have to bear in mind that we are only seeing the tip of the iceberg, as most of the cases are asymptomatic or with mild symptoms, which means that probably only serious cases end up at hospitals, especially in Western Andalucía, although also increasingly in the north. Climate change, the increase in temperatures in recent years and spring rains this year mean that all the conditions are in place for it to be a summer with lots of mosquitoes, which is what will favour the transmission of the virus.

-So Malaga is an ideal place for the transmission of the virus, isn't it?

Yes.

-What tropical viruses are arriving in Andalucía and Malaga?

-Well, I don't know if we should say that this virus has arrived - it is already with us. In fact, a few weeks ago, José Miguel Cisneros, the head of infectious diseases at the Virgen del Rocío, gave a lecture at a course on our campus and said that perhaps we should consider calling it the Guadalquivir virus.

The issue is that we’ve always treated viruses and tropical diseases as something foreign to Spain. We have to take into account that there is a significant population movement, there are more and more international trips, there are more and more migrants living in Spain. Additionally, climate is changing and if not the entire Spanish Mediterranean, then at least Andalucía, Murcia and Valencia are becoming regions with an almost subtropical climate. Within this, we must also talk about dengue fever.

-What about the dengue fever?

Mosquitoes are widely distributed throughout the Mediterranean area of Andalucía. Every year of the last decade we have had sporadic outbreaks with a small number of cases and there is nothing to prevent a chain of transmission in Spain. It is not about someone carrying the disease coming here on a trip, then a mosquito bites them and transmits it to two other people. No, the virus stays here.

Let's take the chikungunya virus. We had the mosquito and a virus that could be transmitted by that mosquito, but there had never been any cases in Latin America. Once it was introduced ten years ago, it caused an epidemic with half a million cases and has since become endemic, triggering outbreaks in various South and Central American regions every year.

-Do we have the chikungunya virus here in Spain?

Not yet, but we have one of the mosquitoes that can transmit it. A person comes incubating the disease from a trip to Brazil or Paraguay, or whichever Latin American. They are bitten by a mosquito that we already have in Malaga and that mosquito bites another person and this can happen at any time.

-Is this disease serious?

Most cases are mild, but the after-effects of joint pain and fatigue are very disabling and often last for weeks or even several months, similar to the symptoms some people have had after Covid-19, making it very disabling. In some cases it can be severe.

-Which would be the most dangerous of these diseases that are now coming to Malaga and Andalucía?

-It's a complex question. I think we have to think above all about the dengue. If the dengue were to become established in Andalucía, we are talking about a disease in In second infections, between 5% and 8% of people develop severe dengue with bleeding. That’s the level of seriousness we’re dealing with.

In terms of how it would change our way of life, let's think about another virus that this mosquito transmits, which is the Zika virus. The Zika virus, of which we have not had endemic cases in Spain so far, usually causes a mild illness. But if you are infected during pregnancy, there is a very high risk of serious malformations of the foetus.

In 2022, our professional society published a book titled Infectious Diseases in 2050. In it, we explored possible future scenarios. In the chapter I co-wrote with a colleague, Míriam Álvarez from Hospital Clínic in Barcelona, we envisioned a situation where, for a couple wanting to conceive, both partners would have to go outside wearing long sleeves, long trousers and applying insect repellent every four hours on all exposed skin, even if it's 40C. That’s because infection now could mean that, if the woman becomes pregnant in three months, the baby might suffer serious malformations. That would be a complete lifestyle change.

This is what I do when I go to South America. Even if it's 40C, with 90% humidity, I wear long sleeves, long trousers and repellent every four hours. Let's imagine a Spain in which our normal day-to-day life in spring and summer is like that. We don't know if it will happen, but it is not unreasonable to believe that it could, in Malaga, for example. Most of the mosquitoes that transmit tropical diseases are already in Andalucía.

-Is any preventive action being taken against this influx of viruses or infectious diseases?

-Very important steps are being taken. The One Health approach is one example, which considers the issue not just as a medical question - it's an issue where all scientific disciplines involved need to work together. The role of veterinary medicine is very important here, especially in the control of mosquito populations. But we still have gaps to fill.

We have no antivirals for the West Nile virus and other such diseases. Except for dengue and chikungunya, there are no vaccines. There’s no human vaccine for West Nile virus, for instance.

We face a clear weakness: with a disease like West Nile virus, where mild cases have very vague, non-specific symptoms, the severe cases (which involve encephalitis) can go undiagnosed for too long, because many other conditions can cause similar symptoms. It is clear that not having specialists in infectious diseases in Spain is a drawback. I am sure that when a patient with suspected Nile virus is seen at Carlos Haya or Virgen del Rocio, in Seville, specialists in their infectious diseases units will quickly suspect the virus and initiate the proper diagnostic steps, so the right samples and information reach the clinical microbiology labs. But this is not the case across the country, not even across all of Andalucía. Some hospitals have dedicated infectious disease experts, while others don’t. And that’s because there still isn't an official medical residency (MIR) specialty in infectious diseases.

- There is no speciality in infectious diseases, is there?

-It does not exist in Spain.

-Why doesn't it exist?

We are the only country in Europe without a speciality, via MIR, in infectious diseases. All over North and South America, there are specialists in infectious diseases. In Spain, we have very good specialists. We are the first country in scientific communications to the European conference of infectious diseases. But they are not trained via MIR, so there is no homogeneity, there is no guarantee that everyone has the same knowledge. That means that if an Andalusian - a patient from Malaga, for example - goes to a doctor with a serious infectious illness, like a multi-drug resistant bacterial infection or suspected West Nile virus, they will have no idea what kind of specialist they're going to get.It’s a completely outdated situation.

-Why is this happening?

-Well, the truth is that for three years we have had a Royal Decree that establishes the conditions under which a new speciality can be created. Our society fulfills all but one of them. The Royal Decree establishes that there has to be a favourable vote from seven regions and this condition has not yet been met. And we are in a situation that I can only describe as Kafkaesque, because this is not political, this is a question of training specialists, it is a question of access to quality health services.

-Another transmission vector is animals, what we call zoonoses. What diseases do animals cause?

Again, this is about a disease we already have in Spain. I believe we need to talk more about Crimean-Congo hemorrhagic fever, a disease transmitted by the bite of a certain kind of tick from the Hyalomma genus, which infects mainly deer in Spain and is widely distributed. There is evidence of transmission in animals all over Spain, including Andalucía. Last year, there was a case in the Sierra de Córdoba. This, once again, shows us the importance of the 'One Health' approach, of the control of these pests. It shows us how the epidemiological panorama is changing. Once again, we're dealing with a disease for which we have no treatment. Many cases are mild, but this is a hemorrhagic fever that, although transmitted by tick bites, can be spread from person to person.

That's why it requires the infrastructure of high-level isolation units. And it's something you could catch just by going for a walk in the countryside and getting bitten by a tick.

So, we're seeing that the range of infectious diseases is becoming more variable, more complex, and demands specialised attention and prevention.

- You say there was one case in the Sierra Norte de Córdoba, but it is not yet widespread?

-As much as we know, it is not. Since the first case was diagnosed in Spain, in 2016, we have had cases every year but one. But there are probably many cases that are not being diagnosed. Recently, a seroprevalence study was published in El Bierzo, which showed that there was a significant percentage of the population that had antibodies to this virus, although no case had ever been counted. So we don't really know how many cases there are. We don't know if there are people who have been diagnosed with another disease or people who haven't been to the doctor. We are running a risk of transmission.

In Madrid, in 2016, a nurse caught this haemorrhagic fever, while carrying for a patient who was not know to have the virus. Luckily, she survived without sequelae. It is not only that diseases arrive, it is that we are often unaware that we have them in our midst. Let's look at 2020. I think all doctors in Spain realised that we had been seing cases of Covid-19 since February, but they were not diagnosed, because there was no suspicion. When the European alert was issued in 2022 for what was then called monkeypox, the next day there were 50 cases under investigation in Spain. These patients had actually been seen up to a month earlier, but in most cases, no one had suspected that virus because they had not been treated by infectious disease specialists.

-And you say many of these tropical diseases don't have a vaccine?

-Most of it.

- What diseases don't we have a vaccine for?

-We don't have a malaria vaccine, we have a dengue vaccine, but it protects well against only some types of dengue, but not against others. A chikungunya vaccine has just been licensed, but it has not yet arrived in Spain because distribution has not yet begun and it has had to be withdrawn due to problems. We don't know for sure if we are going to be able to use it in all patients and at the moment it is not being used in people over 65 years of age. We have no Zika vaccine, we have no Crimean-Congo vaccine, we have no West Nile vaccine. These are neglected tropical diseases. They have no commercial interest and we are not aware that they are a problem for us and, therefore, the research is not being done. That is why a global approach is necessary.

- There is obvious antibiotic resistance in some of these cases. What problems does that create and how are they being fought?

The last study we did tells us that, for every death in Spain in 2023 from traffic accidents, we had 20 from infections by antibiotic-resistant bacteria. This is a serious problem. Right now, we are in a worse situation than we were a century ago when penicillin was discovered.

It is true that there is a research effort and we have new tools, new antimicrobials, but there are two problems here. The first is the importance of personalised medicine and access to microbiological diagnosis. Antibiotics do not fit all. There are no stronger or weaker antibiotics. We need to know which bacteria we are treating, what resistance mechanisms they have and then choose the right antibiotic for that bacterium.

A study published last year by the Hospital Clínico in Barcelona showed that having a microbiology laboratory that worked at night and having infectious disease specialists who received the data in real time and did not wait until 8am the next day to treat these patients reduced mortality. The second problem, obviously, is that these tools that are arriving, these new antibiotics, this information from the microbiology laboratories, need specialists who know how to handle them. If not, there will be an abuse of antibiotics and patients who do not receive the latest generation of the antibiotic they need at the right time.

-What have we learned from the Covid-19 pandemic in the field of infectious disease?

We have learned many things. We have learned that we have to respond more quickly and that need to have the capacity to disseminate information. We have learned that we have to make an effort in communication: we are currently fighting or making an effort against disinformation, the rapid access we have to information, the fact that we do not know how to differentiate quality information. We are working to ensure that what happened in 2020 does not repeat, to make sure that the public knows that the media is not the most appropriate or the most knowledgeable source. Of course, we have also learned that, to be properly prepared, we need these microbiology laboratories open 24 hours a day, seven days a week.

-Should there be one in every hospital centre open 24 hours a day? 

-There should be one in every hospital centre open 24 hours a day. It's not something that can wait for Monday, it's not a cholesterol level. It is something that puts the patient's life at risk and every hour that passes from the time a sepsis process starts until the right antibiotic is given increases the risk of that patient dying.

-Are we prepared to stop and contain another pandemic early?

-We are better prepared. The effort currently being made by the administrations to establish a strategic reserve of medication, antivirals and personal protective equipment is to be commended. We have improved the availability of microbiology services, but we have weaknesses. The Spanish public health agency has still not got off the ground due to political issues that we are not going to go into. We believe this agency should include not just public health and preventive medicine experts, but also clinicians and microbiologists who understand all aspects of disease.

After HIV, after SARS-CoV-2, after avian flu, after the flu pandemic in 2009, after Ebola in 2014 with cases in Spain, after Covid-19, not having specialists is something we can only describe as insane and a big mistake.

- Finally, STIs continue to increase steadily and now they seem to be affecting the over 60s and young people. What are the most common ones? Are there any that are coming in stronger?

-Well, we have to remember that HIV is still circulating and new cases are still being diagnosed. Paradoxically, a very good tool that we have had in recent years in Spain, which is to give antivirals to people who are going to have risky relationships and who are not going to follow the precautionary practices, has led some of these people to lose their fear of STIs (sexually transmitted infections) and to catch other STIs. For example, we should mention the increase in gonorrhoea and the emergence in some countries of antibiotic-resistant gonorrhoea. The truth is, we're seeing a surge in many clinics where we previously didn’t even have consultations for sexually transmitted infections. Now we're having to open new ones, we have waiting lists, and we're seeing more and more cases. Indeed, there's a noticeable increase in all these conditions - chlamydia, etc.