Asian Pacific Journal of Tropical Medicine

1

Authors: Xiao-zhen Li, Wen-ting Cao, Wan-ting Xia, Hai-rong Huang, Tai-cheng Wang

Objective: To systematically analyze the prognosis of limited hilar hepatectomy versus combined liver lobectomy in the treatment of hilar cholangiocarcinoma. Methods: We searched CBM, CNKI, VIP, Wangfang, PubMed, SCI, Elsevier clinicalkey and OVID, and the cut-off time of searching was 31 April, 2019. Two researchers evaluated the risk of bias of the included studies independently according to the Newcastle-Ottawa Scale (NOS), and extracted data. RevMan 5.3 software was used for meta-analysis. Results: A total of 12 cohort studies involving 1 288 patients were included, of which 426 patients were in the limited hilar hepatectomy group and 862 patients in the combined liver lobectomy group. Meta-analysis showed that there were statistically significant difference in radical resection rate and postoperative complication rate (RR=0.55, 95%CI 0.40 to 0.74, P<0.001; RR=0.63, 95%CI 0.49 to 0.81, P<0.001) between the hilar limited hepatectomy group and the combined liver lobectomy group; significant differences were found in 1-, 2- and 3-year survival rates (RR=0.75, 95%CI 0.67 to 0.84, P<0.001; RR=0.55, 95%CI 0.42 to 0.74, P<0.001; RR=0.54, 95%CI 0.39 to 0.75, P<0.001) between the two groups. Conclusions: Comparing with the limited hilar hepatectomy, the radical resection rate of combined liver lobectomy was higher, and the 1-, 2- and 3-year survival rates were improved, but the complications was increased in treatment of hilar cholangiocarcinoma.

3

Authors: Rang-ru Liu, Zu-tao Yu, Zhuo Chen, Dan-qi Liu, Feng-ying Huang, Qian-bin Li, et al

Objective: To identify the molecule mechanism of potential cytotoxicity and proapoptosis of 9za in non-small cell lung cancer (NSCLC) cells. Methods: MTT assay, cell cycle detection kit, JC-1 staining assay were adopted to detect the cell viability, the cell cycle distribution and the mitochondrial membrane potential, respectively. Cell apoptosis was measured by Annexin V-FITC/propidium iodide apoptosis detection and the morphology was observed under a light microscope and the colorimetric TUNEL assay. Western blot was used to monitor the cell cycle-, apoptosisrelated proteins and some proteins involved in the pathways. Results: MTT assay showed that 9za significantly weakened the viability of NSCLC cells. Cell cycle analysis demonstrated that the low concentrations of 9za arrested the cell cycle at G0/G1 phase, which was further confirmed by the down-regulated levels of Cyclin D1, cyclin-dependent kinase 4 and cyclin-dependent kinase 6. In addition, Annexin V-FITC/propidium iodide apoptosis analysis, morphological observations and TUNEL assays revealed that the high concentrations of 9za could induce cell apoptosis. Furthermore, the JC-1 staining assay indicated that the mitochondrial membrane potential was reduced after 9za treatment. Western blot also manifested that 9za dramatically decreased the protein levels of the total Bcl-2, Cytochrome C in the mitochondria and BCL2 associated X in the cytoplasm. However, the levels of BCL2 associated X in the mitochondria, Cytochrome C in the cytoplasm, cleaved caspase-9, cleaved caspase-3 and the ratio of cleaved- PARP1/PARP1 showed the opposite trends. Moreover, the dose-dependently decreased phosphorylation levels of PDK1, protein kinase B, MEK and extracellular signal regulated kinase 1/2 following 9za treatment confirmed that 9za was indeed a double MEK/PDK1 inhibitor as we expected. Coadministration with PD0325901 or BX517 strengthened the cytotoxic and pro-apoptotic effect of 9za, verifying that 9za inhibited cell proliferation and induced cell apoptosis through the double MEK/PDK1 signaling pathways in NSCLC cells. Conclusions: This study demonstrates that 9za could play the effect of cytotoxicity and pro-apoptosis via the dual MEK/PDK1 signaling pathways in NSCLC cells and provides certain experimental foundation for 9za as a new type of drug candidate against non-small cell lung cancer.

5

Authors: Guo-tian Lin, Jie Li, Yue-cai Yu, Chan-juan Zhao, Li-min He, Zhuo Chen1, Fan Zhang

Objective: To observe the correlation between glycosylated hemoglobin level and blood pressure, and to provide clinical evidence to assist the screening and prediction of hypertension among diabetic patients in tropical setting. Methods: A total of 906 diabetic patients who had previously received physical examination at the Second Affiliated Hospital of Hainan Medical University from January 2009 to December 2018 were selected. Retrospective case-case study method was used. The average glycosylated hemoglobin level (HbA1c) was (5.80±1.27)%, and average blood pressure level was (129±18/79±10) mmHg. Patients were divided into group A: blood glucose well controlled, HbA1c<6.5%, (58.82±12.16) years old (754 cases); and group B: blood glucose poor controlled, HbA1c≥6.5%, (60.22±11.82) years old (152 cases). There was no significant difference in age between the two groups (T=-1.302, P=0.186). T-test, χ2-test, spearman correlation analysis and receiver operating characteristic (ROC) curve analysis were used to observe the correlation between glycosylated hemoglobin level and blood pressure, and the prevalence of hypertension. Results: Group B showed higher systolic blood pressure (134.19±18.62) mmHg vs (127.76±17.21) mmHg, diastolic blood pressure (81.82±10.92) mmHg vs (79.00±9.42) mmHg and blood glucose level (9.10±3.09) mmol/L vs (5.52±0.95) mmol/L than group A (T values were 4.335, 3.226, 14.142, respectively, P values were all <0.001). Spearman correlation analysis showed that HbA1c was positively correlated with systolic and diastolic blood pressure (the correlation coefficients r were 0.154 and 0.121, respectively, P values were all <0.001). The prevalence rates of hypertension were 31.17% (235/754) in group A, and 43.4% (66/152) in group B, and the difference was statistically significant [χ2=8.562, OR=1.695, 95% CI (1.187-2.419), P=0.003]. ROC curve of glycosylated hemoglobin was drawn to screen hypertension and the results showed that AUG was 0.587 [95% CI (0.548-0.626), P<0.001], the cut-off point, sensitivity and specificity were 6.05%, 33.6% and 78.2%, respectively. Conclusions: There was positive correlation of glycosylated hemoglobin and blood pressure and it is a novel view of using HbA1c to screen and predict hypertension among diabetic patients in tropic settings. More researches are needed in this field.

7

Authors: Mi Li, Kai Li, Ning Ding, Yi-qiang Xie, Kun Niu, Hong Zhang

Objective: To observe the effects of electroacupuncture on the expression of CREB and its ability to blind to synaptic key proteins in rats with post-traumatic stress disorder (PTSD), thus to lay the foundation for further study of the mechanism of electroacupuncture treatment of PTSD (i.e., electroacupuncture promotes the interaction between synaptic plasticity and BDNF-TRKB signaling pathway). Methods: SD male rats were randomly divided into blank group, model group and electroacupuncture treatment group, with 8 rats in each group. The model of PTSD was established by single continuous stress method (this modeling method is dominated by forced drowning, and tropical disasters are also mostly related to drowning). After modeling, the treatment group received electroacupuncture therapy, followed by retaining the needles for 20 min. The treatment was conducted once daily for 21 d. The behavioral changes were evaluated by spontaneous activity and conditional fear reaction. The expression of CREB was detected by immunohistochemistry and Western Blot. The binding ability of CREB to synaptic protein was verified by CHIP. Results: Compared with the model group, the spontaneous activity distance of the treatment group rats increased (P<0.01) and the percentage of stiffness time decreased (P<0.01), the expression of CREB protein in the treatment group was significantly increased (P<0.01), the binding ability of CREB to PSD95 protein was increased in treatment group (P<0.05). Conclusions: Electroacupuncture regulates the interaction mechanism between synaptic plasticity and BDNFTrkB signaling pathway of the rat model of PTSD, most likely by increasing the binding ability of CREB to the key synaptic protein-PSD95.

9

Authors: Shan-shan Wang, Yue Wu, Huan-huan Zhou, Wen-qi Wang, You Zhang, Wei Zhao, Xiu-ji Cui, Li-hua Li, Jing-long Chen, Lang-yu Rao, Jiang Du, Fei-fei Yin, Gang Lu

Objective: Polyomavirus infection is reported in a wide range of mammalian and avian hosts, including asymptomatic infection, acute systemic disease, and tumor induction.This study aims to obtain and characterize the complete genome of rodent polyomaviruses, PyVs-HMU. The host of virus was a Rattus norvegicus in the residential areas of Hainan Island, China. Methods: The liver samples of Rattus norvegicus were collected from the residential areas of Hainan Island, and then processed with a viral particle-protected, nucleic acid purification method. The extracted RNA and DNA were amplified by sequence-independent PCR. The amplified viral nucleic acid libraries for the samples of Rattus norvegicus were then sequenced using an Illumina GAII sequencer for a single read of 100 bp in length. The raw sequence reads were then filtered using previously described criteria to obtain valid sequences. Results: We obtained the complete genome of a novel polyomaviruses, PyVs-HMU. The genomic sequence of PyVs-HMU has been submitted in GenBank under accession number MK372231. The complete genome of PyVs-HMU is 5318 nucleotides (nt) in length with a G+C content of 45.36%. The complete PyV-HMU sequences display the representative genome organization of polyomaviruses. The genome contain antigens of spliced small T (STAg), middle T (MTAg) and large T(LTAg), and a noncoding control region (NCCR) separate the late region of structural VP1, VP2, and VP3 proteins. The STAg, LTAg, VP1, VP2, VP3 and MTAg encoded proteins of 194, 776, 384, 347, 228 and 414 amino acids (aa) respectively. Phylogenetic analyses depend on LTAg amino acid sequence revealed that the PyV-HMU to be a relative lineage beside a cluster comprising RnorPyV1(KR065723). Conclusions: The discovery of PyV-HMU expands the geographic range of polyomavirus and will provide further insights into the ecology and evolution of PyVs in rodents and humans. The identification of the novel rodent PyVs will provide basic data for the control of emerging zoonotic infectious diseases.

11

Authors: Huan-huan Zhou, Xin-li Zheng, Tian-ming Ma, Zong-xi Cao, Zhe Chao, Li-min Wei, Quan-wei Liu, Rui-ping Sun, Feng Wang, Yan Zhang, Wei Zhao, Gang Lu

Objective: To investigate the infection rate and genotype distribution of Enterocytoon (E.) bieneusi in farmed black goats from the Hainan Province, China. Methods: A total of 341 fresh fecal samples were collected from black goats farmed in five different locations of the Hainan Province, China. E. bieneusi was examined and genotyped through PCR and sequencing analysis of the internal transcribed spacer (ITS) region of this pathogen. Results: The average prevalence of E. bieneusi in black goats from from the five locations was 24.0% (82/341) ranging from 6.3% (4/63) to 37.2% (32/86) (X2=17.252, P<0.01). The detected 82 E. bieneusi isolates belonged to eight ITS genotypes including six known genotypes (AHG1, CHG2, CHG3, CHG5, CM21 and D) and two novel genotypes (HNG-I and HNG-II). Amongst the genotypes, CHG5 was the the most prevalent with a prevalence of 57.3% (47/82), followed by CHG3 (28.0%, 23/82), CHG2 (4.9%, 4/82), CM21 (3.7%, 3/82), D (2.4%, 2/82), AHG1 (1.2%, 1/82), HNG-I(1.2%, 1/82) and HNG-II(1.2%, 1/82). In those genotypes, only genotype D was found in humans previously. Conclusions: This represents the first report identifying E. bieneusi in black goats from Hainan Province of China. The results indicate that E. bieneusi has a high prevalence and a wide distribution in those animals from Hainan Province, but the risk of zoonotic transmission of E. bieneusi from them to human is low.

13

Authors: Kun Niu, Qian Niu, Yi-qiang Xie, Fan Yang

Objective: To explore the clinical effects of tropical Eucommia ulmoides compound-Rattan Moxibustion liquid external rubbing therapy which is from medicine of Li Nationality in Hainan combined with SET sling exercise therapy technique and lumbar-abdominal muscle training program on treating nonspecific low back pain (NLBP) as well as its influence on serum 5-hydroxytryptamine and beta-endorphin levels. Methods: From June 2016 to June 2018, 42 NLBP patients were admitted to the outpatient and ward of Rehabilitation Department of the First Affiliated Hospital of Hainan Medical College, who were randomly divided into control group (n=21) and experimental group (n=21). On the basis of traditional massage manipulation, the control group adopts lumbar and abdominal muscles training, while Rattan Moxibustion liquid external rubbing therapy combined with SET sling exercise therapy was used in the experimental group. The treatment was given once every other day, three times a week and 20 min each time for 8 weeks. Then ODI index and VAS scale of low back pain, as well as serum 5-HT and beta-EP levels were observed and detected. Results: The improvement in low back pain index ODI index of the experimental group were better than that of the control group (control group from 21.23±1.57 to 4.78±0.86 while experiment group from 21.27±1.36 to 2.75±0.64 after 8 weeks’ treatment)(P<0.05). VAS scale decreased significantly in the experiment group compared with control group (control group from 6.62±1.51 to 2.71±0.92 while experiment group from 6.71±1.55 to 1.83±0.79 after 8 weeks’ treatment)(P<0.05). Serum 5-HT in the experimental group were significantly improved compared with those in the control group [control group from (70.15±20.64) ng/mL to (127.34±40.59) ng/mL while experiment group from (68.72±19.18) ng/mL to (142.65±38.72) ng/mL after treatment](P<0.05) and beta-EP level ameliorates compared with control group [control group from (180.63±51.87) pg/mL to (225.76±57.63) pg/mL while experiment group from (172.39±50.72) pg/mL to (251.26±62.89) pg/mL after treatment](P<0.05). Conclusions: Tropical herb-Rattan Moxibustion liquid external rubbing therapy combined with SET sling exercise therapy technology shows significant effects on NLBP. The mechanism may be related to the improved serum 5-HT and beta-EP levels.

15

Authors: Yong Wang, Ming-ming Zou

Objective: To investigate the adsorption kinetics and thermodynamic characteristics of phenylethanoid glycosides (PGs) in the leaves of Callicarpa nudiflora on macroporous resins and provide a reference for the separation and purification of these compounds. Methods: With adsorption and desorption ratio as indexes, optimum types of macroporous resin for purification of PGs were selected from 8 kinds of macroporous resins by static adsorption and desorption tests, and then adsorption kinetics model and adsorption isotherm model of PGs were established to investigate their adsorption processes. Results: SP-825 and SP-207 resin were selected and they have similar adsorption process for PGs. Both of them showed a fast adsorption in 0-60 min, a slow adsorption in 60-360 min, and an equilibrium adsorption stage after 360 min. Adsorption dynamic behavior was well described by quasi-second-order equation of both SP-825 and SP-207 macroporous resins, and adsorption rate was mainly controlled by liquid film diffusion and intraparticle diffusion. Equilibrium adsorption data fitted Langmuir and Freundlich isotherm equations well. Both of the two kinds of resins showed good adsorption properties for PGs, and the adsorption process belongs to favorable adsorption. Conclusions: Both of the kinetic model and thermodynamic model can well describe the adsorption process of SP-825 and SP-207 macroporous resins and the two resins were regarded as excellent adsorption resins for the purification of PGs from the leaves of Callicarpa nudiflora.

17

Authors: Yang-zhi Peng, Yue Su, Yong Jiang

Background: Chinese herbal medicine have been reported to have less side effects in treatment of depression disorder than Western antidepressants, while the mechanism remains unclear. Our previous studies have shown that combined use of Radix Morinda officinalis and Cortex cinnamomi have antidepressant effects Objective: To explore the mechanism of combined use of Radix Morinda officinalis and Cortex cinnamomi in treating depression disorder. Methods: Sixty SD rats were randomly divided into experimental group, control group, model group and blank group with 15 rats in each group. After establiment of depression models, the experimental group and control group were given the Chinese decoction (2 mL/day) and fluoxetine hydrochloride (2 mL/day) respectively for 3 weeks, meanwhile the model group and blank group were fed with normal saline (2 mL/day). Body weight measurement and sucrose preference test were performed regularly. Finally, the rats were sacrificed after treatment, and the hippocampus were taken to detect 5-hydroxytryptamine, norepinephrine, and dopamine contents. Results: The experimental group showed increased body weight and sucrose consumption than the other groups. Higher 5-hydroxytryptamine, norepinephrine and dopamine contents were also observed in the experimental group than other groups. Conclusions: The antidepressant effects of Radix Morinda officinalis and Cortex cinnamomi decoction may show antiexpression effects by up-regulating content of 5-HT, NE, and DA in rats’ hippocampus.

19

Authors: Qiu-juan Lu, Bing Zhang , Li Cao

Objective: To understand the current status of AIDS epidemic among men who had sex with men (MSM) in Haikou, and to analyze the influencing factors to assess the risk of HIV/AIDS infection in MSM group, and then provide a theoretical basis for MSM population to prevent HIV transmission. Methods: Snowball sampling method was used to find men who had homosexual intercourse in oral sex or anal sex in the past year and conducted a questionnaire survey of them. Blood samples were collected to detect three antibodies against: HIV, syphilis and hepatitis C (HCV). Excel 2007 and SPSS22.0 software were used for statistical description, 2 test and logistic regression analysis. Results: A total of 408 MSMs were investigated in this study, 27 HIV infections were detected, with a positive rate of 6.6%. Univariate analysis showing there were statistically significant differences in the prevalence of AIDS in ethnic minorities, local residence time, condom use for same-sex anal sex in the past 6 months, people with sexually transmitted diseases in recent one year, syphilis, and gonorrhea (P<0.05). Logistic regression analysis showed that minority nationality and HIV infection sexually transmitted disease in the past year were risk factors for HIV infection, and condom use for same-sex anal sex in the past 6 months, the opposite sex occurred in the last 6 months and high education level are protective factors for HIV infection. Conclusion: The HIV infection rate of the MSM population in Haikou is high. It is necessary to increase the use of condoms in the MSM population. For low-education MSM, it is necessary to strengthen the dissemination and education of AIDS-related knowledge, so as to reduce the spread of AIDS in the MSM population.

21

Authors: Aisha Khan, Qudsia Rasib, Sajida Riaz, Isthiaq Ali, Naveeda Riaz, Muhammad Sohail Afzal, Muhammad Asif Gondal, Haroon Ahmed

Objective: HIV is a worldwide contagious disease and recent emergence in transgenders reflecting the alarming situation in Pakistan. Transgender people are one of the most affected groups by the HIV epidemic and are 49 times more likely to be living with HIV than the general population. HIV is an emerging disease in Pakistan. Transgender people in Pakistan often face legal, economic, social and religious exclusion. Even though research on HIV/AIDS has conducted since several years ago, still we have a little knowledge about HIV in transgender people. This study aims to investigate the current status of HIV infection among Pakistan transgender population. Methods: Overall cases of HIV in 2017 were retrieved from all four provinces of Pakistan by using all available published data. Results: In 2017, totally 66 264 positive HIV cases were reported in transgenders from Punjab (n=52 656), Sindh (n=13 596) and KPK (n=22) provinces of Pakistan. In Sindh province majority of the patients were from Karachi (n=9 123) followed by Hyderabad (n=1 062), Sukkur (n=1 609), Larkana (n=1 130), Mirpurkhas (n=289) and Nawabshah (n=383), respectively while in Khyber Pakhtunkhwa (KPK), the number of HIV/AIDS transgender patients increased up to 450, out of which 22 cases were registered under provincial AIDS control program in 2017. Conclusions: More efforts by international agencies are needed to combat HIV among transgender communities in Pakistan. Government and NGOs should collaborate to find some strategies for control and prevention of HIV. Social and human rights activists should help and encourage them mainly at the point where their legal rights are not respected. Transgender communities and health department should go hand in hand. Initiatives should be taken to link social justice, human rights, health and advocacy to prevent HIV among transgender in near future.

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Authors: Aisha Khan, Muhammad Sohail Afzal, Muhammad Isthiaq Ali, Naveeda Riaz, Haroon Ahmed

Leishmaniosis is a disease caused by a Leishmania protozoan parasite, which is transmitted by the bite of an infected sand fly. Leishmaniasis is among the most dangerous and neglected tropical diseases. In Pakistan, limited research work has been done yet on this neglected disease. Overall cases of leishmaniasis were retrieved from Khyber Pakhtunkhwa (KPK) and Baluchistan provinces from 2018 to 2019. The major risk factors responsible for these outbreaks were also determined. Recent outbreak resulted in more than 28 000 cases of leishmaniasis in KPK from November 2018 to April 2019. Many of the cases were children and approximately 7 810 diagnosed patients did not receive treatment with meglumine antimoniate. Leishmaniasis cases were also identified in the tribal areas of Khyber (n=9 378), Mohmand (n=5 373), Kurram (n=525), Orakzai (n=163), and Karak (n=554). In Balochistan, around (n=5 000) cases of leishmaniasis were reported in 2018 from the District of Killa Abdulla. The poor infrastructure and sanitary conditions increase the breeding and resting sites of sandflies. The local population’s poor socio-economic conditions increase access to sandflies and the risk of acquiring leishmaniasis. In Pakistan, leishmaniasis is currently neglected by the health authorities, largely due to a lack of data on the number of cases and the monetary and non-monetary impacts that these cases are having on the country. There is a dire need for outreach activities to provide information to communities about the disease and preventive measures. This is a call to the national and international research communities, and to the WHO, to take notice of the threat of leishmaniasis in Pakistan and to help devise a strategy to address this neglected yet important public health problem.

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Authors: Aisha Khan, Sadia Selim Khan, Muhammad Sohail Afzal, Muhammad Asif Gondal, Muhammad Isthiaq Ali, Naveeda Riaz, Majid Mehmood, Haroon Ahmed

reported in Tanzania. The symptoms of chikungunya are joint pain and fever. In Pakistan, cases were reported from different areas especially from Karachi. Many other cases of chikungunya were reported from Rawalpindi and Islamabad. Chikungunya cases were recorded from published data from Dec 2016 to September 2018 in different geographic regions of Pakistan. Chikungunya cases are being reported from many areas of Pakistan, but it is most common in Sindh. A total of 766 cases of chikungunya have been reported from all over Pakistan from Dec 2016 to September 2018. The prevalence of disease varied in different areas of Pakistan: FATA is 0%, Islamabad 4%, GB 0%, AJK 0%, Punjab 8%, Sindh 62%, KPK 22% and Baluchistan 4%. Mosquito breeding sites to human tenancy cause significant risk factor for dengue fever and chikungunya. There is no comprehensive treatment available of chikungunya in Pakistan. Generally speaking, antiviral drugs are administered during viral attack, but there is no antiviral drug for this dangerous disease. The WHO responds to chikungunya by providing guidance, technical support to many underdeveloped countries so they can effectively manage cases of chikungunya.

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Authors: Tian-le Tang, Yi-ji Li, Wang-yuan Wei, Jia-gang Guo

Dengue fever is one of the most serious mosquito-borne infectious diseases in the tropical world, causing substantial human morbidity and mortality, yet there is no specific treatment till now, and the main measures preventing dengue fever include applying pesticide to kill adult vector mosquitos and removing standing water to prevent the breeding of mosquitoes etc. Appropriate uses of such approaches can reduce dengue epidemic risk via reducing mosquito density. In fact, vector control using insecticides is the most common method to prevent and control mosquito-borne disease transmission. Nevertheless, recent research has shown that Aedes albopictus and Aedes aegypti, the two key vectors for dengue fever transmission, have rapidly developed high resistance to the most commonly used adult insecticide pyrethroid (deltamethrin and permethrin) and larvicide organophosphate (temephos). Therefore, it is of great significance to obtain a new drug with longer-term efficacy to prevent dengue virus transmission. Pesticides currently used act on adult stage of mosquitoes, typically applying to the environment where mosquito bites (on humans) occur, and very few target on egg or juvenile stages of the mosquitoes in the water environment. Calcium cyanamide (CaCN2), widely used as a fertilizer in many different settings, was recently shown to have potential to prevent tropical diseases by eliminating or inhibiting the growth and development of intermediate hosts. The main compounds of calcium cyanamide (CaCN2) are CaCN2 (50%- 60%) and calcium oxide (15%). The representative products of calcium cyanamide (CaCN2) are PERLKA® from Germany and ROEBON® from China. CaCN2 has recently been recognized to have the fungicidal effect on the pathogens of the soil borne diseases and addition of CaCN2 could benefit the thermophilic phase and the composting could quickly reach the sanitary standard and will contribute to solve the feces disposal problems. According to our team's long-term investigation and research, we found that ROEBON® (50% CaCN2) can be used to eliminate Oncomelania and effectively control the spread of schistosomiasis. In the latest research, we have confirmed that 10 mg/L CaCN2 (20 mg/L ROEBON®) can completely inhibit the emergence of mosquito larvae and the population growth from the perspective of inhibiting development and the efficacy can lasts for three months. Calcium cyanamide is a good candidate drug to control mosquito-borne infectious diseases transmission, especiallly for dengue fever prevention. In 2014, Scientific Committee on Health and Environmental Risks in European Commission promoted preliminary opinion on potential risks to human health and the environment from the utilization of calcium cyanamide as fertilizer, but convincing evidences for the causal connections between the exposure to CaCN2 and human health damages are missed. Given a 96-h acute zebrafish toxicity study, the No Observed Effect Concentration (NOEC) of calcium cyanamide to zebrafish was 100 mg/L CaCN2. In summary, most of the data are based on the evaluation of the effect of CaCN2 as a fertilizer, and the related research as a mosquito inhibitor is still very scarce. The research on toxicity of CaCN2 in mosquitoes needs to be further strengthened.

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Authors: Li-hua Li, Jing-chen Xie, Jin-Long Chen, Lang-yu Rao, Li-xian Wu, Hui Huang, Gang Lu

Objective: To describe a case of Strongyloides (S.) stercoralis infestation with severe lung involvement in a patient who had pemphigus and treated with prednisone and to analyze the molecular characteristics of the S. stercoralis isolate. Methods: A 54-year-old Chinese man living in rural area of the Hainan Province, China. He had a 1-year history of pemphigus and took prednisone for more than six month. He was admitted to the hospital with a 1-week history of abdominal pain, nausea and vomiting. Two days before admission, he presented with cough, expectoration, and shortness of breath after activity accompanied by fever. Computed tomography (CT) of the chest was performed at different stage of admission. Gastric juice, sputum and stool sample smears were examined under light microscope. The larvae of Strongyloides were found from gastric juice, sputum and stool samples of the patient and the genomic DNA of the larvaes was extracted. PCR amplification of the cytochrome c oxidase subunit 1 (cox1) gene was carried out for the DNA sample and the products were sequenced. Results: CT of the chest on day 1 of admission showed inflammation in the tongue segment of the upper lobe of the left lung and the lower lobe of both lungs and the subsequent CT of the chest revealed extensive bilateral pulmonary infiltrates. PCR amplification and sequencing analysis of the Strongyloides larvae directly colleted from the gastric juice, sputum and stool samples on day 10 of admission showed that 100% homology with the sequence of S. stercoralis isolated in a human from Iran (GenBank No. MG995852). Clinical and imageologicalimprovement was achieved after treatement of albendazole (600 mg/day). Conclusions: This is the first case report of pulmonary S. stercoralis infection in a patient with pemphigus treated with prednisone in Hainan Province of China. We suggested that strongyloidiasis should be routinely investigated in patients presenting with nausea, vomiting, diarrhea, cough or expectoration which were accompanied by fever, especially for patients with low immune function or immune deficiency.

31

Authors: Yu-yan Wu, Qin-mei Liu, Jin-na Wang, Tian-qi Li, Zhen-yu Gong, Juan Hou

Objective: Monitoring the density of Aedes(Ae.) albopictus was very important in evaluating the efficiency of vector management, especially when Aedes-borne diseases break, like Dengue fever, Chikungunya fever and Zika. Human landing catch (HLC) is regarded as the “gold standard” for Aedes monitoring, but it is unsafe and unethical since it potentially expose field professionals to a series of pathogens. In this study, we compared HLC with human-baited double net (HDN) and BG trap for field Aedes albopictus monitoring.The study aims to find an effective and safe alternative method to HLC in monitoring Ae. albopictus, especially in emergency monitoring. Methods: Latin square design was used, and three sites in Hangzhou city, Zhejiang province, China, were chosen to conduct outdoor HLC, HDN and BG trap catches in June. The tests were performed at three periods: a morning period (8:30-10:00), an afternoon period (15:00-16:30), and an evening period (16:30-18:00). Then a table with 81 elements was made to compare the efficiency of these three methods. Results: A total of 80, 138 and 78 adult Ae. albopitus was captured by HDN, BG trap and HLC, respectively. Among these three catches, BG trap showed the best efficacy in captured Ae. albopitus adults. The mosquitoes caught by HLC and BG trap were nearly the same at all three time series, but the density of mosquitoes caught by HDN at 16:30-18:00 was 2 times the density at 8:30-10:00 (4.44 vs 2.22 per hour). In this study, significant positive correlation between HLC and BG trap of Aedes albopitus female density was found (r=0.921, P<0.001). However, no statistical significant correlation between HLC and HDN, BG trap and HDN of Ae. albopitus female density was found (r=-0.46, P=0.820; r=0.019, P=0.923, respectively). Besides, the human-bait attraction bias of HLC catches might be more apparent than BG trap and HDN catches. Conclusions: According to our study, with high efficiency, less human-bait attraction bias, and significantly positive correlation with HLC in catching Ae. albopitus females, BG trap could be a sensitive and safer alternative to HLC for outdoor Ae. albopitus monitoring. It also showed strong potential in emergency monitoring when Aedesborne diseases break.

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Authors: Gao-yu Wang, Li-yuan Zhang, Shu Wen, Wen-qi Wang, Xiao-yuan Hu, Ruo-yan Peng, Yi Huang, Zhang-li Lin, Kun-liang Wu, Gang Lu, Jasper Fuk-woo Chan, Long Sun, Kwok-yung Yuen, Yong-guo Du, Fei-fei Yin

Objective: To identify the epidemiology and clinical features of scrub typhus in Hainan Province, China. Methods: A total of 258 patients with acute febrile illness were recruited from four hospitals in Hainan between 1st June 2018 and 31th August 2019. Orientia tsutsugamushi-specific IgM/IgG and DNA were detected by goldimmuno- chromatographic assay and PCR on the patients’ serum samples. The clinical and epidemiological characteristics of the laboratory-confirmed cases were recorded using a predesigned database. Results: The positive rates of IgM and IgG were 22.5% (58/258) and 39.9% (103/258), respectively, and the positive rate of PCR was 19.37% (50/258). There were 55 males and 48 females among the 103 IgG-positive patients. Patients of all age groups were affected (10 to 86 years); 65.0% of the adults aged 41 to 70 years (67/103); 64.1% of the patients were farmers (66/103). The patients resided in 12 counties and cities of Hainan, and the highest number of cases being reported among residents in Qiongzhong County and Haikou City (54/103, 52.4%). Seasonal variations in the incidence rate of scrub typhus was observed, with the peak incidence (53/103, 51.5%) occurring in the summer (June to August). The common presenting symptoms were fever (103/103, 100.0%), eschar or skin ulcer (38/103, 36.9%), and chills and rigors (30/103, 29.1%). The major complications were liver dysfunction (9/103, 8.7%). Four genotypes of Orientia tsutsugamushi were identified among these patients, including Karp, Kato, Gilliam and Ta763. The predominant genotype was Karp (33/51, 64.7%). Conclusions: Scrub typhus is endemic in Hainan, which predominantly affects residents with prolonged outdoor activities such as farming.

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Authors: Xi-wen Liu, Ling Wu, Xiao-dan Wang, Wei-ling Xu

Objective: To investigate suicide status and influence of medical students in Hainan, and analyze the direct and indirect effects of influencing factors on suicide ideation among college students based on the structural equation mode1. Methods: By using multi-stage sampling method, we selected 696 students of 11 majors of Hainan Medical College as the research subjects, by questionnaire, simplified coping style questionnaire, Adolescent Self-Rating Life Events Scale (ASLEC), self-rating depression scale (SDS), social support rating scale, the self-esteem inventory and the Self-rating Idea of Suicide Scale(SIOSS) was conducted. Results: The idea of suicide in Hainan Medical College students occurred in 15.4%, and suicide act ideation rate was higher in male than in female (χ2=7.161, P=0.006), non-medical higher medical (χ2=6.004, P=0.014). The goodness of fit for the structural equation model was satisfactory and major indices had met corresponding requirements. The depression was a direct influencing factor on suicide ideation, while three factors including social support, positive coping style and passive coping style had indirect impacts.Negative life event and selfesteem not only directly affected suicide ideation, but also had indirect effects.According to the percentages of their contribution, the risk factors were ranked as follows: depression (45.6%), negative life event (33.6%) and passive coping style (18.5%). Similarly, the top protective factors were self-esteem (37.0%), followed by social support (28.4%) and positive coping style (14.3%). Conclusion: The higher incidence of suicide idea of students at the Hainan Medical College, depression and selfesteem were the main factors of suicide ideation. So, it is of great importance to not only strengthen the mental health of college students, but also to train students to face up the difficulties with a positive style, and provide the college students with sufficient social supports.

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Authors: Jie-ying Wang, Zi-hua Tong, Chun-chun Yu, Yu-cheng Li, Yan-qun Xie, Hua Pei

Objective: To preliminarily investigate the infection status of the human immunodeficiency virus (HIV), hepatitis B virus (HBV), treponema pallidum and hepatitis C virus (HCV) in pregnant women in Hainan Province, so as to provide evidence for effective prevention and treatment of mother-to-child transmission. Methods: From October 2017 to July 2019, 8 970 pregnant women who came to our hospital for outpatient examination during pregnancy were tested for HIV, treponema pallidum and HCV antibody by ELISA and tested for rapid detection of HBV surface antigen in serum by gold immune-chromatographic assay. Results: The positive rate of HIV, treponema pallidum and HCV antibody was 0.01% (1/8 970), 0.65% (58/8 970) and 0.11% (10/8 970), respectively, and the positive rate of HBV surface antigen was 11.13% (998/8 970). Conclusions: Among the 8 970 pregnant women, the HBV infection rate was the highest (11.13%), significantly higher than that of the other three infectious diseases, followed by the treponema pallidum and HCV positive rate, and the HIV positive rate was the lowest. Therefore, it is suggested that pregnant women should strengthen prenatal examinations to improve the awareness of prevention of infectious diseases, which is conducive to prepotency. Meanwhile, it is urgent to improve the screening and treatment for epidemic infectious disease in Haikou.

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Authors: Gang Lu, Wei Zhao, Huan-huan Zhou, Mei-fang Xiao, Yong-juan Yu, Hai-fen Nong, Wei Xiang

Objective: To report a case of aural myiasis in an infant and molecular identification of larva species. Methods: A larva was extricated from left external auditory canal of an infant in the Neonatal Department of the People’s Hospital of Baisha County, Hainan Province on 25 June 2019. The larva was placed in 70% alcohol and sent to the Department of Pathogenic Biology, Hainan Medical University. The morphological characters of larva was observed under stereoscopic microscope. The genomic DNA of the larva was extracted and amplified by PCR targeting mtDNA cytochrome c oxidase subunit 1 gene of Diptera, then the PCR product was sequenced and analyzed. Results: A 5-day-old male infant with neonatal hyperbilirubinemia became suddenly irritable. Physical examination found bleeding of the left external auditory canal. A larva about 1.0 cm×0.2 cm was found in the left external auditory canal when the left ear was cleaned with saline. The infant was transferred to Hainan Women and Children’s Medical Center for further examination. Otoscopic examination found that the right external auditory canal was normal, with a small amount of yellow secretion and intact tympanic membrane. However, the left ear canal was slightly swollen, with a small amount of yellow secretion and no obvious perforation of the tympanic membrane. The child was discharged after four days of treatment with appropriate medication. Morphological characteristics observed by stereoscopic microscope implied that larva was the maggot of Sarcophaga sp. PCR amplification and sequencing analyses confirmed that the larva was Sarcophaga (S.) peregrina. The sequence exhibited 100% homology with the S. peregrina c oxidase subunit 1 gene (GenBank No. AF259509.1). Conclusions: This is the first report of an infant with aural myiasis in Hainan Province. The molecular characteristics suggest that the aural myiasis was caused by S. peregrina. One of the factors causing infant arual myasis might be residual amniotic fluid in the external auditory canal of the newborn.

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Authors: Sadia Selim Khan, Aisha Khan, Nazeer Hussain, Muhammad Sohail Afzal, Muhammad Asif Gondal, Haroon Ahmed

Theileriosis is a disease caused by protozoan parasites which belong to genus Theileria. It can be transmitted through ixodid ticks. Mostly the distribution of Theileria species are restricted to subtropical and tropical regions. Theileria species cause economically significant diseases in cattle, sheep, and goats in Pakistan by infecting domestic and wild ruminants. This is a neglected disease in Pakistan because limited research work has been done yet on it. Ovine theileriosis cases were recorded from published data from 2013-2016 in different geographic regions of Pakistan. The intensity and risk factors were also determined in KPK Province of Pakistan. Theleriosis have been reported from all over Pakistan during period 2013-2016. The prevalence of Theleria annulata in buffaloes ticks was 72.91% (875) in urban regions of Hyderabad and it was 80.8% (970) in periurban regions during period 2013-2014. In 2016, prevalence of ovine theileriosis in KPK districts was as 27.5% in Dera Ismail Khan, 13% in Tank and 19.5% in Bannu. It is concluded that paying close attention to animal keeping, feeding and housing may diminish the occurrence of theileriosis in sheep. The higher prevalence might be due to lack of awareness by the community, farming system of the rural livestock of, absence of diagnostic facilities, expensive acaricidal drugs and poor economic condition of farmers.

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Authors: Sha-sha Yu, Jie Qin, Qiu-xia Li, Pan Wang, Jing Wang, Ting-ting Liu, Ying Wang

Objective: To investigate the effect of sublethal dose of Bacillus sphaericus (Bs) 2 362 strain on the malaria transmission ability of Anopheles (An.) dirus (Hainan strain) and its molecular mechanism. Methods: Firstly, the fourth instar larvae of An. dirus was treated with sublethal dose of Bacillus sphaericus. The surviving larvae were then collected and placed into mosquito cages, where they were hatched into adult mosquitoes. These mosquitoes were recorded as Bs group. Meanwhile, the control group was set without any treatment. Then, for infection with Plasmodium yoelii BY265 RFP, 3- to 5-day old female adults were kept at 24 ℃ and fed on Plasmodium yoelii BY265 RFP-infected Kunming mice with a gametocytemia above 0.5%. On day 9-11 post infection, mosquitoes were dissected, and the oocysts on the midguts were examined under a fluorescence microscope. Thirdly, total RNA was extracted from mosquitoes of Bs group and the control group at different time-points respectively, and the cDNA were synthesized later. Finally, SYBR quantitative PCR was conducted to investigate the expression of Imd pathway anti-malaria molecules at different time-points, including TEP1 and Rel2, in Bs and control group mosquitoes. Results: Bs treatment remarkably reduced the infection rate of Plasmodium from 23.71% (124/523) to 16.23% (87/536) (Chi-square test, P=0.002<0.05), and the intensity of Plasmodium infection was greatly decreased in Bs group than that of the control group, either (Mann-Whitney Rank Sum Test, P<=0.001). However, the rate of melanization mosquitoes was 4.97% (26/523) in the control group and 5.78% (31/536) in Bs group, respectively; no significant difference was detected between them (Chi-square test, P=0.558> 0.05). Additionally, the intensities of melanized oocysts were compared between the two groups, and no significant difference was found, either (P=0.566>0.05). Interestingly, compared with the control group, the expression levels of TEP1 and Rel2 in Bs group were obviously up-regulated in larval, adult and infected mosquitoes. Especially in 3 dpi and 7 dpi, the expression level of TEP1 in Bs group was nearly 4 times higher than that of the control group, while Rel2 reached to approximately 7 times. Conclusions: We firstly found that the sublethal dose of Bs significantly suppressed the vector competence of An. dirus to malaria parasites, which revealed a new important role of Bs on the basis of killing mosquito larvae. Furthermore, the Imd signaling pathway might play an effective way in Bs impacting the vector competence of An. dirus through upregulating the expression of NF-kB transcription factor Rel2, enhancing the expression of TEP1, which killed the Plasmodium, but not through melanization.