Overview of Erythropoietic Disease
Erythrocytosis is a zoonotic infection caused by erythrocyte parasites on the surface of erythrocytes, plasma and bone marrow in many animals and humans. Human erythrocytosis can have a variety of clinical manifestations, mainly fever, fatigue, easy sweating, drowsiness and other symptoms, and in severe cases there may be anemia, jaundice and liver, spleen enlargement, lymph node enlargement in different parts of the lymph nodes and so on.
Causes
Erythrocyte body, short for Erythrocyte, is a kind of microorganism parasitized on the surface of human and animal red blood cells, plasma and bone marrow. Observed in general smear specimens, its morphology is polymorphic, such as spherical, ring-shaped, disk-shaped, dumbbell-shaped, racket-shaped and comma-shaped, etc., and its size fluctuates greatly. Erythrocytes parasitized in humans, cattle, sheep and rodents are small, with a diameter of 0.3-0.8 μm. Erythrocytes have both protozoal and rickettsial characteristics, and their taxonomic status could not be determined for a long time until Neimark et al. 1997, who used DNA sequencing, PCR amplification, and 16SrRNA sequence analysis, and believed that they should belong to the genus Mycoplasma in the family of Zygomycetes. So far 14 species of the genus Epimycetes have been identified, of which five are predominant. Erythrocytes parasitized in different animals have their own names. Erythrocyte resistance is not strong, in 60 ℃ water 1 minute that is to stop the movement, 100 ℃ water 1 minute all inactivation, the commonly used disinfectant drugs are generally very sensitive, can be quickly killed, but in the low-temperature freezing conditions can survive for several years.
Symptoms
Incubation period of 2 to 45 days. Most patients do not show clinical symptoms after infection with Eutychia, and only when the proportion of infected red blood cells reaches a certain level does it manifest itself as eutychiasis. Therefore, the severity of human erythroplasia varies, and the clinical manifestations are diverse. The degree of severity depends mainly on the strength of the immune function of the infected person and the proportion of red blood cells infected by erythrocytes. If the immune system is strong, only a small number of red blood cells can be infected (less than 30%), then the pathogen will only be latent in the body, without the onset of disease, after a period of time to eliminate themselves. However, in immunocompromised people or children, it is possible for Erythrocytes to infect a larger number of red blood cells (30% to 60%), which will then cause clinical manifestations. If more than 60% of the red blood cells in the body are infected with Erythrocytes, more serious clinical symptoms will occur and may even lead to death.
The main clinical manifestations are as follows.
1. Fever
The body temperature is usually 37.5℃～40℃, accompanied by excessive sweating and joint pain.
2. Anemia
Anemia is the most common manifestation of the disease, and in severe cases, there may be yellow staining of the sclera and skin, and symptoms such as generalized weakness, drowsiness and mental depression.
3. Enlarged lymph nodes
Some patients have enlarged superficial lymph nodes, commonly in the neck.
4. Other
Itchy skin, enlarged liver and spleen, diarrhea (more common in children), hair loss and so on.
Examination
Laboratory tests
1. Blood picture
Peripheral blood leukocyte count is mostly normal, a few may be elevated, and the classification is normal; red blood cell count and hemoglobin amount are decreased, and the proportion and absolute value of reticulocytes are increased; platelet count is decreased in some patients.
2. Pathologic examination
(1) Direct smear microscopy is the main means of diagnosing human and animal erythropoietic disease, and it is also the most common, fastest and most direct method of examination. The patient’s peripheral blood smear, Rachel’s stain (or Rachel’s – Jimsa stain), in the oil microscope (1,000 times) under the count of 100 erythrocytes, where the red blood cells infected with Erythrocytes <30 for mild infection; 30 to 60 for moderate infection; > 60 for severe infection.
(2) Electron microscopy is mainly used to study the morphology, structure, reproduction and erythrocyte relationship, damage to erythrocytes, impact, etc. Scanning and transmission electron microscopy can also be used to confirm the diagnosis.
(3) Biological Diagnosis Inoculate healthy small animals (e.g. mice, rabbits, chickens, etc.) or chicken embryos with human or animal blood suspected of suffering from Erythropoietic Disease, observe their performance after inoculation, and collect blood to check for Erythropoietes. Diagnosis with this method is time-consuming, but there is a certain auxiliary diagnostic significance.
(4) Serological diagnostic methods Serological methods can not only diagnose echinococcosis, but also do epidemiological investigation and monitoring. However, the serologic diagnostic method of echinococcosis is rarely studied in China.
(5) Molecular biology technology At present, DNA hybridization and PCR technology have been established internationally for the diagnosis of echinococcosis.
3. Blood biochemical examination
Total bilirubin is increased, mainly indirect bilirubin, blood glucose and blood magnesium are low, and liver function is often abnormal.
Imaging examination
4 Ultrasonography may show liver and spleen abnormalities.
Diagnosis
Diagnosis is made on the basis of epidemiologic features, clinical manifestations and laboratory tests.
1. Epidemiologic characteristics
The disease occurs in summer and fall when the humidity is high after rain, and most patients have a history of contact with diseased animals.
2. Clinical manifestations
Patients have fever, weakness, sweating, drowsiness, joint pain and other symptoms. Some patients show progressive anemia, jaundice, hepatosplenomegaly and superficial lymph node enlargement.
3. Laboratory diagnosis
Peripheral blood smears are stained with Rachel’s stain or Rachel’s-Kimsa stain and examined under oil microscope for the presence of worms. If necessary, bone marrow smear can be made.
Differential diagnosis
This disease should be distinguished from malaria, black fever, anemia and other diseases.
Treatment
Mainly symptomatic treatment and pathogenic treatment.
Commonly used antimicrobial drugs are: ① tetracycline, 6 to 12 hours once (children, pregnant women and renal insufficiency should not be used). ② Doxycycline or minocycline, once every 12 hours (not suitable for children under 8 years old). ③ Gentamicin, intramuscular injection, once every 12 hours. ④Butamidokanamycin, intramuscular injection, once every 8 hours. ⑤ Levofloxacin, intravenous drip, once every 24 hours.