Association between trajectories of systolic blood pressure and frailty outcome in middle-aged and older adults.

OBJECTIVES: The association between blood pressure and frailty outcome in the middle-aged and older population remains controversial. This study aimed to examine the relationship between trajectories of systolic blood pressure (SBP) and new-onset frailty. DESIGN: Cohort study with a 7-year follow-up. SETTING AND PARTICIPANTS: Data were derived from 4 waves (2011, 2013, 2015 and 2018) of the China Health and Retirement Longitudinal Study and 6168 participants aged ≥45 years were included in the study. METHODS: The frailty index (FI) was constructed based on 40 scored items, with FI ≥ 0.25 defined as frailty. We identified the 5-year trajectory of SBP by latent class trajectory modeling. The association between SBP trajectories and frailty was explored based on hazard ratios (HR) by four Cox proportional hazards models. Furthermore, we also investigated the relationship between mean SBP and systolic blood pressure variability (SBPV) and frailty. RESULTS: 6168 participants were included in this study with a mean age of 59 years. We identified five trajectories based on SBP, which are maintained low-stable SBP (T0), moderate-stable SBP (T1), remitting then increasing SBP (T2), increasing then remitting SBP (T3), and remaining stable at high SBP levels (T4). During the 7-year follow-up period, frailty outcome occurred in 1415 participants. After adjusting for other confounders, the two trajectories labeled "T2" and "T4" were associated with a higher risk of frailty compared with T0. In addition, elevated SBP and increased SBPV were associated with risk of frailty. CONCLUSIONS: Higher risk of frailty occurred in two trajectories, remitting then increasing and remaining stable at high SBP levels, were associated with a relatively higher risk of frailty.

[Seroepidemiology of pertussis in healthy population in Ningbo, 2019].

Objective: To understand the seroepidemiological characteristics of pertussis in healthy population in Ningbo, and estimate the overall incidence of pertussis. Methods: A cross-sectional survey method was used in this study. A total of 1 206 healthy residents in 9 age groups were stratified randomly selected from 3 counties of Ningbo. Serum samples were collected from the subjects, and the pertussis toxin immunoglobulin G antibody (PT-IgG) levels were measured quantitatively by enzyme-linked immunosorbent assay (ELISA). Results: The mean PT-IgG seropositive rate in the subjects was 0.91% (95%CI:0.45%-1.63%) with a geometric mean titer (GMT) of 3.10 (95%CI:2.86-3.36) IU/ml. The seropositive rates ranged from 0.00% to 1.68%, and the GMTs ranged from 2.08 IU/ml to 5.28 IU/ml in 9 age groups. The incidence rate of pertussis was estimated to be 4 572.81 per 100 000 in age group ≥5 years (95%CI:1 807.30 per 100 000-9 348.12 per 100 000), and the peak of estimated incidence rates were found in age group 5- years (9 301.62 per 100 000, 95%CI:1 121.77 per 100 000-33 154.68 per 100 000) and age group ≥50 years old (8 967.02 per 100 000, 95%CI: 1 059.45 per 100 000-31 845.94 per 100 000). Conclusions: The actual incidence of pertussis was high in Ningbo in 2019. As a result of waning immunity after vaccination, pertussis can occur in adolescents and adults. The pertussis surveillance should be strengthened and the pertussis vaccination strategy should be improved.

[Molecular epidemiology of norovirus associated with pediatric acute gastroenteritis in Beijing in 2020].

Objective: To investigate the molecular epidemiology of norovirus associated with pediatric acute gastroenteritis in Beijing under the Working Mechanism for Joint Prevention and Control of the Epidemic in 2020. Methods: This was a retrospective, repeated cross-sectional study. Fecal or vomit samples (1 213 cases) were collected from children visited the Capital Institute of Pediatrics Affiliated Children's Hospital for acute gastroenteritis from January 1 to December 31, 2020. First, real-time reverse PCR (RT-PCR) was used to screen the samples for norovirus, and then RdRp gene and capsid gene VP1 of norovirus-positive samples were amplified by conventional RT-PCR for genotyping based on the nucleotide sequence. The χ2 test was used to compare the positive rates and genotypes of norovirus among different specimen types, genders of children, and different age groups. Results: Among the 1 213 samples were collected, 215 samples were positive for norovirus, with a positivity rate of 17.7% for the whole year. The peak of norovirus infection observed mainly in the cold seasons, as the positive rates were 28.6% (18/63), 26.2% (16/61), 22.8% (77/338) and 17.1% (89/520) in January, October, November and December, respectively. The positive rate of norovirus in fecal sample was significantly higher than that in vomit sample (χ2 = 9.692, P<0.01). There was no significant difference between genders (χ2=0.041, P>0.05), but significant difference was found between age groups with the highest rate in the 6-48 months group (χ²=103.112, P<0.01). Three genogroups (GⅠ, GⅡ and GⅨ) of the circulating virus were detected by G-gene typing, and GⅡgenogroup was predominant, accounting for 98.5% (196/199). Among the GⅡ positive samples, genotype GⅡ.4 Sydney (55.1%, 108/196) was the most common, followed by GⅡ.2 (29.6%, 58/196), while the GⅡ.3 norovirus (10.2%, 20/196) which was common in previous years was not as much as before. Based on the P-type, GⅡ.P16 was predominant (61.5%, 96/156), followed by GII.P31 (19.9%, 31/156). The dual genotyping revealed that GⅡ.4 Sydney [P16] (36.4%, 56/154) and GⅡ.2 [P16] (24.7%, 38/154) were predominant. Conclusion: The prevalence of norovirus in children in 2020 in Beijing is not much different from those of the previous years, but the genotypes composition has changed significantly, and there are multiple genotypes circulating simultaneously.

[Midterm outcome comparison between patients with bicuspid or tricuspid aortic stenosis undergoing transcatheter aortic valve replacement].

Objective: To compare the prognosis of transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic valve (BAV) or tricuspid aortic valve (TAV) stenosis. Methods: This was a retrospective study. Patients with symptomatic severe aortic stenosis, who underwent TAVR with follow-up time more than one year in Guangdong Provincial People's Hospital from April 2016 to August 2018, were included. According to aortic CT angiography, the patients were divided into BAV group and TAV group. The primary endpoint was the composite event of all-cause death and stroke, and the secondary endpoints were TAVR-related complications. Incidence of clinical endpoints and parameters derived from echocardiography were compared between the groups, and Kaplan-Meier survival analysis was used to compare the composite event between the two groups. Results: A total of 49 patients were included. The age was (73.6±6.3) years, and 25(51.0%) were male. There were 32 patients in BAV group and 17 in TAV group, the follow-up time was 466 (390, 664) days. The incidence of composite endpoint of death and stroke at one year were comparable in BAV and TAV groups (6.3% (2/32) vs. 5.9% (1/17), P=1.00). Kaplan-Meier curves also showed a similar risk of the composite endpoint(HR=1.03，95%CI 0.09-11.24，Log-rank P=0.98) between two groups. The incidence of all-cause death, stroke, myocardial infarction, severe bleeding, major vascular complications, new-onset atrial fibrillation or atrial flutter, and permanent pacemaker implantation were all similar between the two groups(all P>0.05), and there was no acute kidney injury (stage 2 or 3) in both groups. Echocardiographic parameters at one year were similar between the two groups (all P>0.05). Conclusions: The midterm prognosis of TAVR in patients with BAV and TAV stenosis is similar. Clinical trials of large sample size with long-term follow-up are warranted to verify our findings.

[Cardiac operation and interventional therapy during pregnancy： an analysis of outcome].

Objective: To explore the efficacy and safety of open cardiac operation and interventional therapy in pregnant patients and describe the feto-neonatal and maternal outcomes. Methods: A retrospective study of 39 cases of women undergoing open cardiac operation or interventional therapy during pregnancy was conducted in Guangdong Provincial People's Hospital from Jan. 2014 to Oct. 2019. Results: The age of 39 pregnant women with gestational heart disease was (30±6) years old (21-43 years old). Among them, 37 cases were single and 2 cases were twin pregnancy. Modified World Health Organization (mWHO) pregnancy risk classification were all level Ⅳ. There were 22 women receiving cardiac operation under cardiopulmonary bypass during pregnancy, 14 patients undergoing percutaneous balloon mitral valvuloplasty, 2 patients accepting percutaneous balloon pulmonary valvuloplasty, and 1 case receiving atrial septal defect occluder with ultrasound guidance. Three were no maternal deaths during and after the operation. One patient had an inevitable abortion. Four fetuses died in the uterine after open cardiac surgery. There patients chose termination of the pregnancy after cardiac operation. There were 31 live birth, in which 7 cases were preterm live birth and 24 patients were term live birth. The total number of newborns were 33. Two fetuses suffered neonatal intracranial hemorrhage and died after birth. Thirty-one fetuses were alive and born without any abnormity. Conclusion: For pregnant women with high risk of cardiovascular disease and classified as mWHO pregnancy risk level Ⅳ, cardiopulmonary bypass and interventional therapy during pregnancy could be used as an alternative for better materal and fetal outcomes.

[Investigation of a cluster epidemic of COVID-19 in Ningbo].

Objective: To investigate a cluster epidemic of COVID-19 after a mass gathering activity in Ningbo of Zhejiang province and analyze the transmission chain and status of infection cases of different generations. Methods: The tracking of all the close contacts of the first COVID-19 case and epidemiological investigation were conducted on January 29, 2020 after a cluster epidemic of COVID-19 related with a Buddhism rally on January 19 (the 1.19 rally) in Ningbo occurred. The swabs of nose/throat of the cases and close contacts were collected and tested for nucleic acids by real-time fluorescence quantitative RT-PCR. Results: From January 26 to February 20, 2020, a total of 67 COVID-19 cases and 15 asymptomatic infection cases related with the 1.19 rally were reported in Ningbo. The initial case was the infection source who infected 29 second generation cases and 4 asymptomatic infection cases, in whom 23 second generation cases and 3 asymptomatic infection cases once took bus with the initial case, the attack rate was 33.82% (23/68) and the infection rate was 38.24% (26/68). The risks of suffering from COVID-19 and being infected were 28.91 times and 26.01 times higher in rally participants taking bus with initial case compared with those taking no bus with initial case. In this epidemic, 37 third+generation cases and 11 related asymptomatic infection cases occurred, the attack rate was 2.88% (37/1 283) and the infection rate was 4.76% (48/1 008). The main transmission routes included vehicle sharing and family transmission. Conclusion: It was a cluster epidemic of COVID-19 caused by a super spreader in a massive rally. The epidemic has been under effective control.

[Relations between high risk sexual behavior and HIV infection among men who have sex with men in ways of meeting male partners].

Objective: To understand the relations between high risk sexual behavior and HIV infection among MSM in ways of finding male partners in Ningbo. Methods: A cross-sectional study was conducted in Ningbo between April and November in 2018. Data related to socio-demographics, ways of finding male partners, adoption of gay apps and sexual behaviors were collected by snowball method. Blood samples were drawn for HIV antibody testing. Classified data was evaluated by chi-square test. Related factors on HIV infection were analyzed by multivariate logistic regression. Results: A total of 735 participants were included in this study. Ways of finding male partners would through gay apps (60.8%, 447/735), QQ/Wechat (32.3%, 237/735) and gay-places (6.9%, 51/735). Related information on high risk sexual behavior and HIV infection among gay apps users were found as: 16.8%(75) had sexual behavior once per week in the past 6 months, 41.8% (187/447) had multiple sexual partners, 12.1% (54/447) had unprotected anal intercourse in the last time, 52.3% (234/447) having had unprotected anal intercourse in the past 6 months. The overall HIV prevalence rate was 12.1%(54/447). Among the HIV cases who got infected within the two years, 68.6%(24/35) of them had used gay apps for less than two years. Results from the, multivariate logistic regression analysis showed that gay apps users were more susceptible to infected HIV than those who used the QQ/Wechat (OR=3.03, 95%CI: 1.30-7.07). Conclusions: Gay apps was popularly known among the Ningbo MSM, and was associated with the high risk sexual behaviors and HIV infection. HIV control and prevention programs should be strengthened in the MSM population who used the gay apps. Related surveillance and intervention programs for MSM, who use the gay apps, need to be further reinforced.

[Correlation between human bocavirus 2 infection in children and acute diarrhea in Beijing].

Objective: To investigate the relationship between human bocavirus 2 (HBoV2) infection and acute diarrhea in children younger than 5 years of age in a case-control study. Methods: This was a prospective case-control study. During May 2016 to December 2016, fecal specimens were collected from children ≤5 years of age with acute diarrhea who visited the Affiliated Children's Hospital of Capital Institute of Pediatrics (case group), or from children ≤5 years of age without diarrhea from Longtan Community Medical Service Center, Beijing (control group). The case group (n=240) and the control group (n=240) were divided into 8 age subgroups: ≤1 month old, >1-3 months old, >3-6 months old, >6-12 months old,>1-2 years old,>2-3 years old,>3-4 years old and >4-5 years old, and there were 30 cases in each age subgroup. The specimens were tested for 7 types of diarrhea-associated viruses, especially for HBoV2 by real-time PCR method. The HBoV2 viral load was predicted according to the cycle threshold (Ct). Finally, t-test was used to compare the differences between groups. Results: In the case group (n=240), the positive rate of norovirus was 16.7% (40 cases); rotavirus, 10.8% (26 cases); HBoV2, 7.5% (18 cases); adenovirus, 7.1% (17 cases); astrovirus, 6.3% (15 cases); parachovirus, 3.8% (9 cases); and Aich virus, 0.4% (1 case). The positive rates of HBoV2 in case group (7.5%, 18 cases) and control group (5.0%, 12 cases) showed no significant difference (χ(2)=1.280, P=0.258), as well as in different age groups (all P>0.05) . However, the mean viral load of the HBoV2 in the case group (1×10(9)copies/L with cycle threshold (Ct) 25.8) was higher than that of control group (1×10(5)copies/L with Ct 33.8), showing a significant difference (t=0.597, P=0.000). Conclusions: Norovirus and rotavirus are still the important viral pathogens in children with acute diarrhea. A higher load of HBoV2 may indicate a higher risk of acute diarrhea in children ≤5 years of age in Beijing.

A suppository kit for metronomic photodynamic therapy: The elimination of rectal cancer in situ.

Metronomic photodynamic therapy (mPDT) was developed to improve tumor-specific responses through cell death by apoptosis. We developed an mPDT suppository kit including ALA and LED suppositories and analyzed its killing effect on rectal tumors in rabbits. METHODS: The ALA (10 wt%) suppository was prepared using ALA powder, type 36 semi-synthetic fatty acid glyceride, and azone. The LED suppository was constructed by encapsulating LED units and a circuit in transparent epoxy resin. VX2 cells were injected into the rectal submucosa of rabbits to establish a carcinoma model in situ. The ALA suppository was inserted into the rectal cavity for 30 min of uptake and activated for 1 h by the LED suppository at a power density of 20 mW/cm2. The mPDT process was repeated three times once a day. MRI was used to monitor tumor growth, histopathology and TUNEL staining were performed at 14 days after mPDT. RESULTS: The overall response rate was 60% in the mPDT group using the kit in which the tumor size was decreased up to about 50% at 7 days post-mPDT and almost eliminated at 14 days. HE staining showed that only 6.16% of the tumor tissue remained after mPDT treatment. TUNEL detection showed that the apoptosis rate was 18.9%. CONCLUSION: We verified the killing effect of the mPDT suppository kit on rectal tumors in rabbits based on mPDT that induced tumor cell apoptosis.

Homogeneous (Cu, Ni)6Sn5 intermetallic compound joints rapidly formed in asymmetrical Ni/Sn/Cu system using ultrasound-induced transient liquid phase soldering process.

Homogeneous (Cu, Ni)6Sn5 intermetallic compound (IMC) joints were rapidly formed in asymmetrical Ni/Sn/Cu system by an ultrasound-induced transient liquid phase (TLP) soldering process. In the traditional TLP soldering process, the intermetallic joints formed in Ni/Sn/Cu system consisted of major (Cu, Ni)6Sn5 and minor Cu3Sn IMCs, and the grain morphology of (Cu, Ni)6Sn5 IMCs subsequently exhibited fine rounded, needlelike and coarse rounded shapes from the Ni side to the Cu side, which was highly in accordance with the Ni concentration gradient across the joints. However, in the ultrasound-induced TLP soldering process, the intermetallic joints formed in Ni/Sn/Cu system only consisted of the (Cu, Ni)6Sn5 IMCs which exhibited an uniform grain morphology of rounded shape with a remarkably narrowed Ni concentration gradient. The ultrasound-induced homogeneous intermetallic joints exhibited higher shear strength (61.6 MPa) than the traditional heterogeneous intermetallic joints (49.8 MPa).

Rapid formation of Ni3Sn4 joints for die attachment of SiC-based high temperature power devices using ultrasound-induced transient liquid phase bonding process.

High melting point Ni3Sn4 joints for the die attachment of SiC-based high temperature power devices was successfully achieved using an ultrasound-induced transient liquid phase (TLP) bonding process within a remarkably short bonding time of 8s. The formed intermetallic joints, which are completely composed of the refined equiaxial Ni3Sn4 grains with the average diameter of 2µm, perform the average shear strength of 26.7MPa. The sonochemical effects of ultrasonic waves dominate the mechanism and kinetics of the rapid formation of Ni3Sn4 joints.

[Expanding test and normalization for HIV/AIDS prevention and control].

Expanding real-name HIV test is the basis of the real-time reporting system in China, and it plays an important role for the progress. In year of 2003, there were 45 092 cases of HIV positives reported cumulatively, which accounted for only 5.4% of the estimated population of HIV positives. Since implementation of real-name HIV test and establishment, real-time reporting system, up to year 2005, the total of reported HIV positives was 577 000, which took up 67.9% of the estimated HIV positives. Also among reported cases, 387 000 cases have received the anti-retroviral treatment. Normalization of HIV prevention and control will pave the way to medical insurance for HIV positives. It is a goal that all the people have medical insurance in China, and the normalization is an ideal working condition, and real-name HIV test is a measure for it. The both are very closely connected and improving each anther.

[Survival analysis of HIV/AIDS patients with access to highly antiretroviral therapy in Ningbo during 2004-2015].

Objective: To understand the epidemiology characteristics and survival status of HIV/AIDS patients with access to highly antiretroviral therapy (HAART) in Ningbo during 2004-2015. Methods: A retrospective cohort study was conducted among HIV/AIDS patients diagnosed between 2004 and 2015. Life Tables were used to estimate survival rates, and Kaplan-Meier curve with Log rank test were used to describe the survival curves and the Cox proportional hazard model was used to determine predictors of mortality. Results: Of the subjects, the median age when starting HAART was 35 years (IQR: 27-45 years). Most of them were males, local residents, married, infected through heterosexual sexual transmission, and their baseline CD4 T cells counts were mainly ≤200 cells/µl, and most of them were at clinical stageⅠ(WHO). The cumulative survival rate was 96.75% for the first year, 92.36% for the fifth year, 91.87% for the seventh year and 90.02% for the tenth year. The risk of the mortality was 17.34 times higher for those aged >60 years compared with those aged ≤20 years (95%CI: 2.11-142.71), 2.83 times higher for those at clinical stage Ⅳ(WHO) compared with those at clinical stageⅠ (WHO) (95% CI: 1.67-4.80) and 3.26 times higher for those with drug resistance compared with those without drug resistance (95%CI: 1.77-6.01). Blood transmission, lower CD4+ T cell level, BMI <18.5, unmarried were the risk factors for the mortality. Conclusions: The effect of HAART was obvious in the HIV/AIDS patients in Ningbo, their survival rate was high. The finding indicated that it is necessary to strengthen the health care for old population and health education about AIDS prevention and control, and conduct large scale screening. Early discovery, early diagnosis, early treatment and improving treatment compliancy are still the effective ways to reduce the mortality.

Molecular cloning and characterization of a C-type lectin in yellow catfish Tachysurus fulvidraco.

This study represents the first report of a C-type lectin (ctl) in yellow catfish Tachysurus fulvidraco. The complete sequence of ctl complementary (c)DNA consisted of 685 nucleotides. The open reading frame potentially encoded a protein of 177 amino acids with a calculated molecular mass of c.y 20.204 kDa. The deduced amino-acid sequence contained a signal peptide and a single carbohydrate recognition domain with four cysteine residues and GlnProAsp (QPD) and TrpAsnAsp (WND) motifs. Ctl showed the highest identity (56.0%) to the predicted lactose binding lectin from channel catfish Ictalurus punctatus. Quantitative real-time (qrt)-PCR analysis showed that ctl messenger (m)RNA was constitutively expressed in all examined tissues in normal fish, with high expression in trunk kidney and head kidney, which was increased following Aeromonas hydrophila challenge in a duration-dependent manner. Purified recombinant Ctl (rCtl) from Escherichia coli BL21 was able to bind and agglutinate Gram-positive and Gram-negative bacteria in a calcium-dependent manner. These results suggested that Ctl might be a C-type lectin of T. fulvidraco involved in innate immune responses as receptors (PRR).

Obese very old women have low relative hangrip strength, poor physical function, and difficulties in daily living.

OBJECTIVES: To investigate whether anthropometric and body composition variables and handgrip strength (HS) were associated with physical function and independent daily living in 88-year-old Swedish women. PARTICIPANTS: A cross-sectional analysis of 83 community-dwelling women aged 88 years who were of normal weight (n=30), overweight (n=29), and obese (n=24) was performed. MEASUREMENTS: Body weight (Wt), height, waist circumference (WC), and arm circumference were assessed using an electronic scale and a measuring tape. Tricep skinfold thickness was measured using a skinfold calliper. Fat mass (FM) and fat-free mass (FFM) were measured using bioelectrical impedance analysis, and HS was recorded with an electronic grip force instrument. Linear regression was used to determine the contributions of parameters as a single predictor or as a ratio of HS to physical function (Short Form-36, SF-36PF) and instrumental activities of daily living (IADL). RESULTS: Obese women had greater absolute FM and FFM and lower HS corrected for FFM and HS-based ratios (i.e., HS/Wt, HS/body mass index [BMI]) than their normal weight and overweight counterparts. After adjusting for physical activity levels and the number of chronic diseases, HS-based ratios explained more variance in SF-36PF scoring (R2, 0.52-0.54) than single anthropometric and body composition variables (R2, 0.45-0.51). WC, HS, and HS-based ratios (HS/Wt and HS/FFM) were also associated with independence in IADL. CONCLUSION: Obese very old women have a high WC but their HS is relatively low in relation to their Wt and FFM. These parameters are better than BMI for predicting physical function and independent daily living.

Unaltered Image of Health Maintenance: An Observation of Non-Participants in a Swedish Cohort Study of 85 to 86 Year Olds.

BACKGROUND: Selection bias is often inevitable in epidemiologic studies. It is not surprising that study conclusions based on participants' health status are frequently questioned. OBJECTIVE: This study aimed to assess whether the non-participants affected the characteristics of a general population of the very old people. DESIGN, SETTING AND PARTICIPANTS: Prospective, cross-sectional (N=650, aged 85 years old) analysis and 1-year follow-up (n=273), in Linköping, Sweden. MEASUREMENTS: We analysed data on health-related factors from a postal questionnaire, a home visit and a clinic visit at baseline and at the 1-year follow-up. We calculated the effect size to evaluate the degree of differences between the groups. RESULTS: A greater proportion of non-participants resided in sheltered accommodation or nursing homes (participants vs non-response vs refusal, 11% vs 22% vs 40, P<0.001, φ=0.24). During the home visit or clinic visit, a higher proportion of dropouts reported mid-severe problems in EQ-5D domains (mobility and self-care) and limitations in personal activities of daily living, but the differences between participants and dropouts were very small (φ<0.2). No significant difference was found between the groups with regard to emergency room visits or hospital admissions, despite the fact that more participants than dropouts (φ=0.23) had multimorbidities (≥2 chronic diseases). Living in sheltered accommodation or a nursing home (odds ratio (OR), 2.8; 95% confidence interval (CI), 1.5-5), female gender (OR, 1.8; 95% CI, 1.1-3.1) and receiving more home visits in primary care (OR, 1.03; 95% CI, 1-1.06) contributed positively to drop out in the data collection stages over the study period. CONCLUSION: Non-participants were not considered to be a group with worse health. Mobility problems may influence very old people when considering further participation, which threatens attrition.

Epidemiological characteristics of malaria in Ningbo City, China 2000-2011.

The objective of this study was to explore the trend and the epidemiological characteristics of malaria in Ningbo from 2000 through 2011 and provide scientific evidence for the prevention and control. Using the retrospective study, data relating to malaria epidemics during 2000-2011 in Ningbo were collected through the questionnaires of the cases and other important surveillance data. Adult mosquitoes were collected using CDC light traps baited with CO2. Results showed that Plasmodium vivax was the main species, and Anopheles sinensis was the only vector species of malaria. The annual incidence rates (per 100000) ranged from 0.156 to 3.224, and about 95.41% of the cases were imported. The cases occurred mainly between May and November and the incidence showed two peaks, and the local transmission of malaria was determined by vector density. Considering the vast majority of these infections were imported vivax malaria cases from domestic endemic areas (particularly Anhui province), and may lead to limited local transmission, strengthening the routine monitoring of imported malaria, ensuring timely diagnosis, improving case detection rate, giving a standardized treatment to patients and intensifying public health education on malaria prevention are extremely important to malaria prevention and control activities.