[Dynamics of routine blood tests in BALB/c mice with Babesia microti infection].

OBJECTIVE: To understand the changes in body weight, spleen weight and complete blood cells in BALB/c mice infected with Babesia microti. METHODS: For the infection group, six weeks old BALB/c mice were injected intraperitoneally with a dose of 100 µL of B. microti infected blood (20% RBC infection rate, each mouse). For the determination of the progression of B. microti infection up to 28 days of the infection, the microscopic visualization of thin blood smears of tail blood stained with Giemsa staining was performed in the infection group. The experiment was carried out at different intervals on days 0, 7, 14, 21, and 28 after the infection, respectively. The mice were sacrificed, and spleens were collected and weighed, and the body weight of the mice was also determined. The blood cells of the mice were analyzed by using Mindray BC-5300 Vet animal automatic hematology analyzer. RESULTS: On the first day after the infection, B. microti was visualized in RBC of the infection group. The significantly highest infection rate (55%) appeared on the seventh day of the infection, and then steadily decreased; the mice attained the latent infection phase on the 28th day post-infection, when the parasite could not be visualized in the peripheral blood. The mice in the infected group acquired a significantly lowest body weight on the 7th day of the infection, and then gradually returned to normal. The weight of the spleen was the significantly highest on the 14th day of the infection, and then consistently decreased. On the 28th day of infection, the spleen weight was still higher than that of the control group. There were no significant changes in the number of white blood cells (WBC), lymphocytes, and eosinophils in the infected mice; and altered levels were all within the normal mouse reference range. The number of red blood cells, hemoglobin, and platelet count in the infected mice were decreased to the lowest level when the B. microti infection rate achieved to the highest, and then gradually returned to the normal levels. CONCLUSIONS: B. microti infection can cause body weight loss, splenic weight gain, and reduction in the number of erythrocytes and platelets in whole blood of the mice. Besides, the whole blood cell analyzer has a diagnostic significance in the identification of babesiosis.

[Prevalence of Entamoeba histolytica infection and its risk factors in Tengchong City, Yunnan Provine: a hospital-based study].

OBJECTIVE: To understand the infection status and risk factors of Entamoeba histolytica in inpatients in Tengchong City, Yunnan Province. METHODS: A cross-sectional study was conducted in the inpatients in Tengchong People's Hospital, Yunnan Province. After obtaining the informed consent from the subjects, the stool samples were collected from 2016-07-01 to 2017-03-31, and nested polymerase chain reaction (PCR) was used to detect E. histolytica in the stool samples. Meanwhile, a structured questionnaire was used to record the demographic information and clinical symptoms for the patients. RESULTS: Totally 507 cases were recruited, and the detection rate of E. histolytica was 1.97% (10/507, 95% CI: 1.07%-3.59%) in all subjects. There were no significant differences between the inpatients with and without E. histolytica infection in the height (Z = -0.40, P = 0.69), weight (Z = -0.34, P = 0.73), body mass index (Z = -0.40, P = 0.69) and age (Z = -1.48, P = 0.14). Chronic diarrhea (OR = 21.43, 95% CI: 5.04-91.23) and daily drinking water (OR = 11.28, 95% CI: 2.79-45.56) were relevant to E. histolytica infection. No significant association was observed between E. histolytica infection and the clinical symptoms, such as abdominal distension (OR = 0.70, 95% CI: 0.09-5.56), inappetence (OR = 0.50, 95% CI: 0.06-4.02), itchy skin (OR = 0.79, 95% CI: 0.10-6.38), perianal pruritus (OR = 1.74, 95% CI: 0.21-14.07), and constipation (OR = 0.91, 95% CI: 0.13-7.33). CONCLUSIONS: E. histolytica infection is high in inpatients in Tengchong City, Yunnan Province, and chronic diarrhea and drinking unboiled water were highly correlated with E. histolytica infection.

[Study on the ARIMA model application to predict echinococcosis cases in China].

OBJECTIVE: To predict the monthly reported echinococcosis cases in China with the autoregressive integrated moving average (ARIMA) model, so as to provide a reference for prevention and control of echinococcosis. METHODS: SPSS 24.0 software was used to construct the ARIMA models based on the monthly reported echinococcosis cases of time series from 2007 to 2015 and 2007 to 2014, respectively, and the accuracies of the two ARIMA models were compared. RESULTS: The model based on the data of the monthly reported cases of echinococcosis in China from 2007 to 2015 was ARIMA (1, 0, 0) (1, 1, 0)12, the relative error among reported cases and predicted cases was -13.97%, AR (1) = 0.367 (t = 3.816, P < 0.001), SAR (1) = -0.328 (t = -3.361, P = 0.001), and Ljung-Box Q = 14.119 (df = 16, P = 0.590) . The model based on the data of the monthly reported cases of echinococcosis in China from 2007 to 2014 was ARIMA (1, 0, 0) (1, 0, 1)12, the relative error among reported cases and predicted cases was 0.56%, AR (1) = 0.413 (t = 4.244, P < 0.001), SAR (1) = 0.809 (t = 9.584, P < 0.001), SMA (1) = 0.356 (t = 2.278, P = 0.025), and Ljung-Box Q = 18.924 (df = 15, P = 0.217). CONCLUSIONS: The different time series may have different ARIMA models as for the same infectious diseases. It is needed to be further verified that the more data are accumulated, the shorter time of predication is, and the smaller the average of the relative error is. The establishment and prediction of an ARIMA model is a dynamic process that needs to be adjusted and optimized continuously according to the accumulated data, meantime, we should give full consideration to the intensity of the work related to infectious diseases reported (such as disease census and special investigation).

[Research progress of Babesia rhoptry associated proteins].

Babesia parasites are obligate intracellular apicomplexan protozoa and important pathogens causing babesiosis of humans and animals. They have conserved subcellular structures and invasion mechanism. Rhoptry-associated proteins, which are released into the host cell, are considered to be the key molecules of invasion and replication of parasites in the host cell and are immunosuppressive factors of the host cell mediated immunity in the stage of parasitophorous vacuole (PV) formation. The knowledge about rhoptry-associated proteins has made a great progress with the development of genomics and proteomics, so we review the research progress in rhoptry-associated proteins of different Babesia including Babesia bovis, B. ovine, B. gibsoni, B. bigemina and B. orientalis, etc.