How malaria is transmitted

Malaria is a vector-borne infectious disease caused by Plasmodium through the bite of Anopheles mosquitoes or transfusion of blood from people carrying Plasmodium. Malaria is not particularly common in today's society, but in the past, I believe people were very familiar with malaria. Once malaria spreads, it spreads very quickly and is very easy to transmit. Let me introduce to you in detail the transmission routes of malaria.

There are four types of malarial parasites that parasitize humans, namely Plasmodium vivax, Plasmodium malariae, Plasmodium falciparum and Plasmodium ovale. In my country, the main species are Plasmodium vivax and Plasmodium falciparum; the other two species are rare, and some cases imported from abroad have occasionally been seen in recent years. Different malarial parasites cause vivax malaria, malaria malariae, falciparum malaria and ovale malaria. The main manifestations of this disease are periodic regular attacks, with chills, fever, and sweating all over the body. After long-term and multiple attacks, it can cause anemia and splenomegaly.

Clinical manifestations

1. Incubation period

The period from when a person is infected with Plasmodium to when they develop the disease (oral temperature exceeds 37.8°C) is called the incubation period. The incubation period includes the entire infrared period and the first reproductive cycle of the intraerythral period. The general duration of Plasmodium vivax malaria and Plasmodium ovale malaria is 14 days, that of falciparum malaria is 12 days, and that of Quarternary malaria is 30 days. Different amounts and strains of infectious protozoa, differences in human immunity, and different modes of infection can all result in different incubation periods. In temperate regions there are so-called long-latency strains, which can last up to 8 to 14 months. The incubation period of transfusion infection is 7 to 10 days. For fetal-transmitted malaria, the incubation period is even shorter. The incubation period may be prolonged for people with a certain level of immunity or who have taken preventive medication.

2. Chilling period

Chills start with coldness in the extremities, followed by coldness in the back and entire body. The skin has goose bumps, the lips and nails are cyanotic, the face is pale, and there are muscle and joint pains all over the body. Then the whole body starts to shiver and the teeth chatter. Some people cannot stop shaking even by covering themselves with several quilts. The shaking lasts for about 10 minutes or even an hour, and then the chills stop naturally and the body temperature rises. Patients often feel seriously ill during this stage.

3. Fever period

After the feeling of cold disappears, the face turns red, cyanosis disappears, and the body temperature rises rapidly. Usually, the more obvious the coldness, the higher the body temperature, which can reach above 40°C. Patients with high fever suffer unbearable pain. Some tossed and turned restlessly, groaning incessantly; some were delirious, staring into space, or even convulsing or losing consciousness; some suffered from severe headaches and persistent vomiting. The patient has red face and shortness of breath; conjunctival congestion; burning and dry skin; rapid and strong pulse; and short and dark urine. They often complain of palpitations, thirst, and desire for cold drinks. It lasts for 2 to 6 hours, and sometimes even more than 10 hours. Herpes is common on the lips and nose after several attacks.