On holiday with no risks for infections. Interview with Angela Santoni
Angela Santoni is the Scientific Director of Pasteur Institute Italy, which has been promoting biomedical research for over 50 years with the purpose of understanding and treating a number of diseases, including infectious diseases. In view of the summer holidays, with thousands of Italians travelling to foreign countries, we asked Professor Santoni for some pieces of advice to keep the risk of infections and viruses under control.
The number of Italians who choose faraway destinations where to spend their summer holidays has been increasing. What are the pitfalls and the recommendations for a trip to an exotic place?
The main risk of travelling to some areas in the world, such as Africa, Asia or America is the possibility to come across some pathogens that may cause infectious diseases, against which our immune system is totally unprepared. This is the reason why it is important that travellers know the characteristics of the hosting country before they start their trip and ask their physicians or appropriate healthcare facilities for a specific vaccination plan which takes into account their destinations as well as their vaccination histories. For example, for some mandatory vaccinations, it could be necessary to receive a booster dose, or it could be appropriate to receive some specific vaccines, such as those against Hepatitis A, cholera, yellow fever and typhoid fever.
Food and beverages are important infection carriers. What risks can hide inside food?
The sanitary conditions of some countries in the world can turn water and food into important infection carriers. For example, hepatitis A is a viral infection that is often transmitted by insufficiently cooked sea fruits and that can seriously compromise liver functions. Another example is typhoid fever, caused by the Salmonella Typhi bacterium, which is transmitted through food and beverages in several countries in Northern Africa and Southern Asia. Today, there is a vaccine against these two diseases which can be administered in combination, if needed. However, an adequate prevention also involves attention to personal hygiene and the habit of washing hands before coming into contact with food.
What dangers lie in eating fish, especially if it is not well cooked or not properly “blast chilled”?
A number of fish species – like anchovies, sardines, squid, hake or mackerel – can host parasites of the Anisakis genre, which are nematode worms against which there is no vaccine. The larvae of this intestinal parasite do not survive if fish is blast chilled to -20°C or if it is cooked at temperatures higher than +50°C. Several countries all over the world, including Italy, have strict rules with regard to this; however, many others have unclear or absent regulations. In these cases, it is appropriate not to eat raw fish and make sure to eat it only if it is very well cooked.
Other important carriers of viruses and infections are mosquitoes. How can we protect ourselves?
Mosquitoes can carry a number of diseases against which vaccines are not always available. This is the case of malaria, which is transmitted by nocturnal mosquitoes of the Anopheles genre, against which it is possible to receive a preventive drug prophylaxis if we travel to world regions at risk. Important infections are also transmitted by diurnal mosquitoes of the Aedes genre, which are responsible for the transmission of the dengue, Zika, Chikungunya and yellow fever viruses. With regard to yellow fever, there is a very effective vaccine based on an attenuated virus, while for the other diseases, due to the fact that there are no vaccines, the main preventive measure is protection against mosquitoes through appropriate clothing and skin repellents.
Can mosquitoes be carriers of infections also at our latitudes?
Over the last two decades, Italy has reported the almost stable presence of tiger mosquitoes, Aedes albopictus, which can promote the transmission of viruses from the blood of travellers coming from endemic areas. This is what happened with the Chikungunya virus, which in 2017 caused an epidemic in Calabria and Lazio, with over 500 cases of people affected by flu symptoms aggravated by skin rush and joint pain, which in some cases have lasted even months.