Malaria prevention and control should be kept in mind
Leaving the country is careless
In March 2024, Mr. Wang, who had finished working in Africa, developed fever, sweating, fatigue, nausea and other symptoms a week after returning to China. Mr. Wang didn't pay attention to it at first, but after a few days, his symptoms did not improve and he was in danger of getting worse, and then went to the hospital. Based on Mr. Wang's clinical symptoms, combined with his travel history in Africa, the doctor recommended screening for parasitic infections. On the same day, the Institute of Parasitic Diseases Prevention and Control of the Chinese Center for Disease Control and Prevention (National Center for Tropical Diseases) tested Mr. Wang's blood smear and found the ring body of Plasmodium falciparum in his blood smear, and was diagnosed as falciparum malaria. Here, we would like to remind the public that:
What is malaria
Malaria (Malaria) is a disease caused by the parasite malaria parasite that seriously endangers human health, especially falciparum malaria, if not treated in time, it will cause anemia, hepatosplenomegaly, impaired bone marrow hematopoietic function, cerebral malaria and other serious conditions, and even death.
Malaria is still a worldwide infectious disease, threatening about 40% of the world's population, especially in Africa, Southeast Asia and South America. After nearly 80 years of hard work, the mainland has dropped from about 30 million cases per year in the 40s of the 20th century to zero local infections since 2017, and successfully obtained the World Health Organization's malaria elimination certification in 2021. However, due to the cross-border movement of people, the mainland still faces the threat of imported malaria for a long time.
The main route of transmission of malaria
The malaria parasite is like a small "hacker", hiding in human liver cells and red blood cells to develop, and one of those mosquitoes that buzz in our ears all day long, Anopheles mosquitoes, is the "accomplice" of the malaria parasite!
Anopheles mosquitoes, the vector of malaria
There are 5 common types of malaria parasites that can infect humans: Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale and Plasmodium knowlesi parasite, whose life history is basically the same, and requires two hosts, Anopheles mosquito and human, Anopheles mosquito is the terminal host of Plasmodium parasite, which carries out sexual reproduction and spore proliferation, and human is the intermediate host of Plasmodium parasite, which carries out asexual proliferation. Plasmodium parasites live in human hepatocytes and red blood cells, and eventually form mature schizonts containing merozoites. After the merozoites in the erythrozoite phase are released, they continue to infect healthy red blood cells, some of which are cyclical, and some of which develop into female and male gametophytes, in preparation for the next step of developing in the mosquito and infecting new hosts.
In this case, Mr. Wang, who works as a carpenter in Africa, often works in jungles and grasslands, which happen to be the habitat of Anopheles mosquitoes with a high population density, and the bite has given the malaria parasite an opportunity to enter Mr. Wang's body.
Two stages after malaria infection
According to the characteristics of the life history of the malaria parasite, human malaria infection can be divided into two stages: the incubation period and the onset phase. The incubation period for different types of malaria varies, ranging from 2 to 3 weeks, as short as 7 days, and as long as years. The attack period refers to the intra-malaria stage, after the density of the plasmodium reaches a certain threshold, a large number of merozoites are released, and their metabolites stimulate the immune system, causing a series of symptoms such as fever and headache.
How malaria is diagnosed
The most common method is microscopic examination. Blood smears containing thick and thin blood films were prepared from the peripheral blood of the patients and stained, and the types and developmental stages of the malaria parasites were distinguished and identified according to the morphology of the malaria parasites in the blood film under the microscope. Immunological and molecular biology tests are also highly sensitive detection methods and can be used as auxiliary diagnosis.
Plasmodium falciparum annoids (8000 ×) in the patient's blood membrane, arrows shown
How to do a good job in malaria prevention and control when leaving the country
At present, Africa, Southeast Asia, the Eastern Mediterranean, and South America are all malaria-endemic areas, and India and Myanmar are the countries with high malaria prevalence among the mainland neighbors. People who work, live or plan to leave the country in endemic areas need to be vigilant at all times and do a good job in malaria prevention and control.
01
Before Departure
Find out about the malaria epidemic situation at your destination and get advice from local health care facilities, the CDC, the International Travel Health Care Center, and more.
02
During the departure period
Take mosquito prevention measures: install mosquito nets, window screens, etc., wear long sleeves and long pants, keep the environment clean and tidy, clean up garbage and stagnant water in a timely manner, and use mosquito repellent products.
03
During the trip and after returning home
Pay close attention to your own health status, seek medical attention in time if you have relevant uncomfortable symptoms, and take the initiative to inform your travel and residence history.
Source: China Center for Disease Control and Prevention