Analysis of the pollution status of paralytic shellfish poisons in shellfish sold in Hainan Province, 2018-2021 / 中国热带医学

@#Abstract: Objective　To investigate the pollution of paralytic shellfish poisons (PSP) in shellfish sold in Hainan Province from 2018 to 2021. Methods　From 2018 to 2021, the content of 10 paralytic shellfish poisons including saxitoxin (STX), neosaxitoxin (neoSTX), gonyautoxins 1 (GTX1), gonyautoxins 2 (GTX2), gonyautoxins 3 (GTX3), gonyautoxins 4 (GTX4), gonyautoxins 5 (GTX5), decarbamoylsaxitoxin (dcSTX), decarbamoylgonyau toxins 2 (dcGTX2) and decarbamoylgonyau toxins 3 (dcGTX3) in 7 kinds of shellfish commonly sold in 13 cities and counties in Hainan province was analyzed. Results　The detection rate of PSP in 360 shellfish samples was 10.3%. Among them, the highest detection rate of STX was 5.83%, followed by GTX2 detection rate of 4.17%; the detection rate of neoSTX and GTX3 were both 1.67%; the detection rate of GTX1 was 1.39%. None of the five PSP, GTX4, GTX5, dcSTX, dcGTX2 and dcGTX3, were detected. Four types of PSP were detected in fanscallops, two were detected in oysters, mussels and Scapharca subcrenata, only one was detected in scallops, and no toxin contamination was detected in clams and razor clams. A single sample of fanscallops detected a maximum of 4 PSP, and a single sample of oysters, scallops, mussels and Scapharca subcrenata detected a maximum of 1 PSP. The equivalence of PSP in all samples was ND-155.6 μg/kg.The annual detection rate of PSP from high to low was: 20.0% in 2020, 15.6% in 2019, 5.3% in 2018, and 2.0% in 2021, and none of the samples tested exceeded the standard. Continuously detectable STX in 2018-2020, all PSP that could be detected in 2018 were STX. In 2019, in addition to STX detected in scallops and Scapharca subcrenata, neoSTX was also detected in oysters, mussels and Scapharca subcrenata. In 2020, PSP was only detected from scallops, and GTX2 could be detected in all positive specimens, while 5 STX, 5 GTX1 and 6 GTX3 were detected. Only GTX2 detected from scallops in 2021. STX was detected in shellfish sold in 12 cities and counties, GTX2 can be detected in 10 cities and counties, neoSTX can be detected in 5 cities and counties, GTX1 and GTX2 were detected in 4 cities and counties respectively. Shellfish sold in Wenchang and Lingshui markets can detect 5 types of PSP. Conclusion　Some types of shellfish on the market in Hainan are contaminated with some kind of PSP pollution risks, and it is necessary to strengthen the supervision of PSP in marketed shellfish.

Biosafety risks and mitigation strategies for mosquito infection in Arthropod Containment Level-2 laboratory / 中国热带医学

@#Arthropods of medical importance such as mosquitoes, ticks and sandflies are one of the key drivers of arthropod-borne diseases outbreak, posing a great threat to global public health security. For further understanding the transmission mechanisms of arthropod-borne diseases and establishing the prevention and control measures, a series of experiments of arthropods infection need to be carried out under laboratory conditions. Besides the regular biosafety requirements, some specific considerations need to be taken into account when performing arthropod infection and the infected arthropod rearing. Except for the physical containment composed of biosafety facilities, a comprehensive assessment of the biosafety risks during operations and corresponding preventive measures are also critical to eliminate or mitigate the biosafety risks. In this paper, we introduce our practice in handling mosquito infection with Risk Group 2 pathogens in Arthropod Containment Level-2 (ACL-2) laboratory, with an aim to provide a reference for researchers in related fields.

Extensive Resistance of Anopheles sinensis to Insecticides in Malaria-Endemic Areas of Hainan Province, China.

Anopheles sinensis is one of the major malaria vectors and among the dominant species in Hainan Province, China. The resistance of An. sinensis to insecticides is an important threat to malaria control. However, few reports on insecticide resistance of An. sinensis were reported in this area. Eight districts in Hainan Province were selected as the study areas. Insecticide susceptibility bioassays were tested on wild-caught female mosquitoes of An. sinensis to 4% dichlorodiphenyltrichloroethane (DDT), 0.05% deltamethrin, and 5% malathion by using the World Health Organization standard resistance tube assay procedure. All the tested An. sinensis mosquitoes demonstrated resistance to 4% DDT, with less than 72% mortality in the standard assay. The populations from Baisha and Qiongzhong demonstrated possible resistance to 0.05% deltamethrin, with 94-95% mortality, whereas the populations from other districts demonstrated resistance to 0.05% deltamethrin in the standard assay. The populations from Baisha, Qiongzhong, and Dongfang demonstrated susceptibility to 5% malathion, but the populations from other districts demonstrated resistance. These results facilitate the improvement of effective control strategies for malaria vector mosquitoes in Hainan.

A Cost-Effectiveness Analysis of Plasmodium falciparum Malaria Elimination in Hainan Province, 2002-2012.

In Hainan Province, China, great achievements in elimination of falciparum malaria have been made since 2010. There have been no locally acquired falciparum malaria cases since that time. The cost-effectiveness of elimination of falciparum malaria has been analyzed in Hainan Province. There were 4,422 falciparum malaria cases reported from 2002 to 2012, more cases occurred in males than in females. From 2002 to 2012, a total of 98.5 disability-adjusted life years (DALYs) were reported because of falciparum malaria. Populations in the age ranges of 15-25 and 30-44 years had higher incidences and DALYs than other age groups. From 2002 to 2012, malaria-related costs for salaries of staff, funds from the provincial government, national government, and the GFATM were US$3.02, US$2.24, US$1.44, and US$5.08 million, respectively. An estimated 9,504 falciparum malaria cases were averted during the period 2003-2012. The estimated cost per falciparum malaria case averted was US$116.5. The falciparum malaria elimination program in Hainan was highly effective and successful. However, funding for maintenance is still needed because of imported cases.

Genetic diversity of Plasmodium vivax population before elimination of malaria in Hainan Province, China.

BACKGROUND: Hainan Province is one of the most severe endemic regions with high transmission of Plasmodium falciparum and Plasmodium vivax in China. However, the incidence of P. falciparum and P. vivax has dropped dramatically since 2007 and a national elimination malaria programme (NEMP) was launched after 2010. To better understand the genetic information on P. vivax population before elimination of malaria in Hainan Province, the extent of genetic diversity of P. vivax isolates in Hainan Province was investigated using four polymorphic genetic markers, including P. vivax merozoite surface proteins 1, 3α, and 3ß (pvmsp-1, pvmsp-3α, and pvmsp-3ß) and circumsporozoite protein (pvcsp). METHODS: Isolates of P. vivax (n = 27) from Hainan Province were collected from 2009 to 2010 and pvmsp-1 and pvcsp were analysed by DNA sequencing, respectively. Using polymerase chain reaction-restriction fragment length polymorphism were analysed in pvmsp-3α, and pvmsp-3ß. RESULTS: The DNA sequencing analysis on pvmsp1 revealed that there were three allele types: Salvador-1 (Sal-1), Belem and recombinant (R) types. Among them, Sal-1 type was a dominant strain with eight variant subtypes (88.9%), whereas R- (3.7%) and Belem-type strains (7.4%) had one variant subtypes, respectively. All the isolates carried pvcsp with VK210 type accounting for 85.2% (23/27 isolates) and VK247 type accounting for 14.8% (4/27). Only type A and type B alleles were successfully amplified in pvmsp-3α gene, and a high level of polymorphism was observed in pvmsp-3α. Considering pvmsp-3ß gene, type A was the predominant type in 17 isolates (63%), whereas type B was dominant in only ten isolates (37%). CONCLUSION: The present data indicate that there was high degree of genetic diversity among P. vivax population in Hainan Province of China during the pre-elimination stage of malaria, with 26 unique haplotypes observed among 27 samples.

Sensitivity of Plasmodium falciparum to antimalarial drugs in Hainan Island, China.

Pyronaridine and artesunate have been shown to be effective in falciparum malaria treatment. However, pyronaridine is rarely used in Hainan Island clinically, and artesunate is not widely used as a therapeutic agent. Instead, conventional antimalarial drugs, chloroquine and piperaquine, are used, explaining the emergence of chloroquine-resistant Plasmodium falciparum. In this article, we investigated the sensitivity of P. falciparum to antimalarial drugs used in Hainan Island for rational drug therapy. We performed in vivo (28 days) and in vitro tests to determine the sensitivity of P. falciparum to antimalarial drugs. Total 46 patients with falciparum malaria were treated with dihydroartemisinin/piperaquine phosphate (DUO-COTECXIN) and followed up for 28 day. The cure rate was 97.8%. The mean fever clearance time (22.5 ± 10.6 hr) and the mean parasite clearance time (27.3 ± 12.2 hr) showed no statistical significance with different genders, ages, temperatures, or parasite density (P > 0.05). The resistance rates of chloroquine, piperaquine, pyronarididine, and artesunate detected in vitro were 71.9%, 40.6%, 12.5%, and 0%, respectively (P < 0.0001). The resistance intensities decreased as follows: chloroquine > piperaquine > pyronarididine > artesunate. The inhibitory dose 50 (IC50) was 3.77 × 10(-6) mol/L, 2.09 × 10(-6) mol/L, 0.09 × 10(-6) mol/L, and 0.05 × 10(-6) mol/L, and the mean concentrations for complete inhibition (CIMC) of schizont formation were 5.60 × 10(-6) mol/L, 9.26 × 10(-6) mol/L, 0.55 × 10(-6) mol/L, and 0.07 × 10(-6) mol/L, respectively. Dihydroartemisinin showed a strong therapeutic effect against falciparum malaria with a low toxicity.

Eliminating Plasmodium falciparum in Hainan, China: a study on the use of behavioural change communication intervention to promote malaria prevention in mountain worker populations.

BACKGROUND: In the island of Hainan, the great majority of malaria cases occur in mountain worker populations. Using the behavioral change communication (BCC) strategy, an interventional study was conducted to promote mountain worker malaria prevention at a test site. This study found the methods and measures that are suitable for malaria prevention among mountain worker populations. METHODS: During the Plasmodium falciparum elimination stage in Hainan, a representative sampling method was used to establish testing and control sites in areas of Hainan that were both affected by malaria and had a relatively high density of mountain workers. Two different methods were used: a BCC strategy and a conventional strategy as a control. Before and after the intervention, house visits, core group discussions, and structural surveys were utilized to collect qualitative and quantitative data regarding mountain worker populations (including knowledge, attitudes, and practices [KAPs]; infection status; and serological data), and these data from the testing and control areas were compared to evaluate the effectiveness of BCC strategies in the prevention of malaria. RESULTS: In the BCC malaria prevention strategy testing areas, the accuracy rates of malaria-related KAP were significantly improved among mountain worker populations. The accuracy rates in the 3 aspects of malaria-related KAP increased from 37.73%, 37.00%, and 43.04% to 89.01%, 91.53%, and 92.25%, respectively. The changes in all 3 aspects of KAP were statistically significant (p < 0.01). In the control sites, the changes in the indices were not as marked as in the testing areas, and the change was not statistically significant (p > 0.05). Furthermore, in the testing areas, both the percentage testing positive in the serum malaria indirect fluorescent antibody test (IFAT) and the number of people inflicted decreased more significantly than in the control sites (p < 0.01). CONCLUSION: The use of the BCC strategy significantly improved the ability of mountain workers in Hainan to avoid malarial infection. Educational and promotional materials and measures were developed and selected in the process, and hands-on experience was gained that will help achieve the goal of total malaria elimination in Hainan.

Pulmonary embolism with acute pancreatitis: a case report and literature review.

Acute pancreatitis is an inflammatory disease characterized by local tissue injury which can trigger a systemic inflammatory response. So vascular complications of pancreatitis are a major cause of morbidity and mortality. Pulmonary embolism in acute pancreatitis has been reported to be very rare. We reported a case of pulmonary embolism with acute pancreatitis. A 38-year-old woman broke out upper abdomen pain without definite inducement. She had no nausea and vomiting, fever, dyspnea, cough and expectoration, chest pain. The patient had been diagnosed with acute pancreatitis in local hospital. The patient was treated with antibiotics and proton pump inhibitors, and the abdomen pain was alleviated slightly. But the patient came forth cough and expectoration with a little blood, progressive dyspnea. A computed tomographic scan of the abdomen revealed pancreatitis. Subsequent computer tomography angiography of chest revealed pulmonary embolism (both down pulmonary arteries, left pulmonary artery and branch of right pulmonary artery). Dyspnea of the patient got well with thrombolytic treatment and anticoagulation therapy. Pulmonary embolism is a rare but potentially lethal complication of pancreatitis. Familiarity with this complication will aid in its early diagnosis, therapy and prevent pulmonary embolism, a rare but catastrophic phenomenon.

Decreased expression of KLF6 and its significance in gastric carcinoma.

To study the expression of the Krüppel-like transcription factor 6 (KLF6) in human gastric carcinoma and normal gastric mucosa tissues, and to explore the role of KLF6 in the carcinogenesis and tumor progression and its clinical significance. Expression of KLF6, P21WAF1 and PCNA was investigated by immunohistochemistry for 69 surgically resected gastric carcinoma tissues and corresponding normal gastric mucosa tissues, respectively. The correlations of KLF6 expression with clinicopathological characteristics, P21WAF1 and PCNA were examined. Positive-expression of KLF6 was 64 out of 69 cases (92.8%) in normal gastric mucosa and only 23 cases (33.3%) in gastric carcinoma. Expression of KLF6 in the gastric carcinoma was remarkably lower than normal gastric mucosa. Decreased expression of KLF6 in gastric carcinoma was significantly associated with histological differentiation (P<0.01), TNM stage (P<0.05), lymph node metastasis (P<0.01) and distant metastasis (P<0.05). There was no significant correlation between KLF6 expression and sex, age. Meanwhile, expression of KLF6 was associated with expression of P21WAF1 in both normal gastric mucosa and gastric carcinoma (P<0.05). In addition, decreased expression of KLF6 in gastric carcinoma was positively associated with PCNA level (r=0.719, P<0.01) by association analysis. Down-regulation of KLF6 might play an important role in the carcinogenesis and development of human gastric carcinoma and have significant clinical value.