From July 1 this year Silvia (Portugal) Supervising the “Plasmodium Biology” research team of the Max Planck Institute in Germany. Covid-19 stopped their activities for three weeks. After that, they returned to the laboratory wearing masks and social distancing and resumed their activities.
Before 2017 and 2018, she and her team carried out field work in Mali with 600 people, ranging in age from 3 months to 45 years old.This research led to a study published in the journal natural Try to clarify the asymptomatic form of this disease.
In his latest work, he talked about how humans become asymptomatic carriers of malaria during the dry season, and how the disease recurs during the rainy season. How does this affect your treatment?
It is well known that in the dry season, malaria parasites remain in asymptomatic carriers. Several research groups have tried before, and we have tried. Do not know what’s going on. It is believed that more immune responses are involved. We found that the parasites lose the ability to promote the adhesion of infected cells to blood vessels, and therefore can eliminate the infected cells in the spleen.
It is not that the parasites will be reactivated when the rainy season returns, but as the mosquitoes return, the mosquitoes absorb some of the parasites and re-transmit there.
Why are asymptomatic people so common in infectious diseases? For covid-19, this has always been one of its control problems.
From an evolutionary point of view, any type of infection is too virulent and kills all hosts, otherwise it would be disadvantageous for it to cease to exist. Perhaps, with the development of time and adaptation, they will all develop into symbiosis (the association between two species without prejudice) or reciprocity (the association between two or more species is mutually beneficial).
Some experts suggest that all these deadly infections are still in the process of adapting to us, and as the adaptation progresses, the virulence should gradually decrease.Other studies have shown that for Plasmodium falciparum The death rate of the people responsible for human malaria is not high enough for further adaptation measures. In other words, since it kills about 1% of infected people, evolutionarily speaking, reducing its virulence level may not be necessary.
What is the risk of these asymptomatic malaria patients?
There are some cases of anemia associated with asymptomatic malaria infection, but this is not always the case.
How do antibodies in malaria work?
It is known that antibodies are very important in fighting diseases. They increase with age and exposure, and can resist the most serious forms of infection. What we described in our last article is that these parasites persist during the dry season and will not help maintain anti-malarial antibodies. That is, whether there are parasites in the dry season will not change the number of antibodies against the disease in these months.
Silvia Portugal (Silvia Portugal) while working in Mali. /Picture provided by the author
What other infectious diseases behave like this? why?
There are many seasonal diseases. During the rainy season, malaria is more frequent, while others prefer malaria to higher temperatures.
Why are there no vaccines for infectious diseases in which so many lives are lost in countries like Africa?
To date, there is no approved vaccine for human parasitic diseases. This is complicated. Compared with viruses or bacteria that we have vaccines, “worms” that are prevented in this way are much more difficult. The problem of preparing vaccines against parasites is huge. But there are some promising candidate molecules in development, and a vaccine has not yet been approved, which can partially protect children from malaria. WHO recommends it be used for experimental introduction in some African countries. It may be approved soon. However, since the protection it provides is not yet complete, work continues to improve or develop better alternatives.
How will the climate crisis affect these infectious mosquito-borne diseases?
We don’t know, but it’s important to stay vigilant and fight climate disturbances. We need to maintain habitats under the diverse biodiversity of plants and animals because they are in danger and must be protected.
In our field research, what we observed during the dry season in Mali has nothing to do with climate change. Before this crisis, there was an alternation between drought and rainy season. The parasite survival strategy may be a response to the need to survive for six months without mosquitoes. Now, we want to look at situations where this has not happened in Africa because this spread is continuous, such as Uganda, Kenya or Gabon.
In another article, he talked about the co-infection between HIV and malaria. Is it common in Africa?
Malaria is a widespread disease, especially among children. HIV affects adults the most. Mergers are not very frequent.
Did we pay enough attention to infectious diseases before mating?
In an industrialized world where population density is high and people have many different interests, for many people, the need to continue economic growth is very important. There are many others who are interested in making development differences between countries smaller and smaller. Of course, more funds can be provided for these diseases!
For covid-19, it was able to succeed because it has become a global pandemic…
Of course, our economic investment in malaria can make the same effort as we did with covid-19, which is cruel. In addition, there are currently many people from the scientific community working on this disease. But I don’t think we will reject infectious diseases. Like the Bill and Melinda Gates Foundation or La Caixa in Spain, many people and resources have been allocated to investigate the fight against these diseases. What is needed is structure, education and economic development means that diseases such as malaria will not have such an impact in the countries where they exist. To achieve this fundamentally requires peace and political stability.