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Li X.-X.,National Institute of Parasitic Diseases | Li X.-X.,National Center for Tuberculosis Control and Prevention | Zhou X.-N.,National Institute of Parasitic Diseases
Parasites and Vectors | Year: 2013

Co-infection of tuberculosis and parasitic diseases in humans is an important public problem in co-endemic areas in developing countries. However, there is a paucity of studies on co-infection and even fewer reviews. This review examines 44 appropriate papers by PRISMA from 289 papers searched in PubMed via the NCBI Entrez system (no grey literature) up to December 2012 in order to analyze the factors that influence epidemic and host's immunity of co-infection. The limited evidence in this review indicates that most common parasite species are concurrent with Mycobacterium tuberculosis in multiple organs; socio-demographics such as gender and age, special populations with susceptibility such as renal transplant recipients, patients on maintenance haemodialysis, HIV positive patients and migrants, and living in or coming from co-endemic areas are all likely to have an impact on co-infection. Pulmonary tuberculosis and parasitic diseases were shown to be risk factors for each other. Co-infection may significantly inhibit the host's immune system, increase antibacterial therapy intolerance and be detrimental to the prognosis of the disease; in addition, infection with parasitic diseases can alter the protective immune response to Bacillus Calmette-Guerin vaccination against Mycobacterium tuberculosis. © 2013 Li and Zhou; licensee BioMed Central Ltd.

Wei F.R.,National Institute of Parasitic Diseases
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases | Year: 2010

To establish a multiplex PCR assay for detecting Angiostrongylus cantonensis larvae in Pomacea canaliculata. A pair of specific primers was designed based on the sequences of the small subunit rDNA of A. cantonensis (GenBank jAY295804), in combination with 16s rDNA specific primers of P. canaliculata, a multiplex PCR was developed. The PCR was performed on positive and negative snails, and the amplified products were analyzed by agarose gel electrophoresis and DNA sequencing. DNA template of 200 III stage larvae of A. cantonensis was diluted by negative snail DNA (1200 ng/microl, 120 ng/microl, 12 ng/microl, 1200 pg/microl, 120 pg/microl and 12 pg/microl), to find the minimum detectable level. Single blind method was used to evaluate the accuracy. After being detected by lung microscopy, 172 snails from field were tested by the multiplex PCR to assess the sensitivity and specificity. Agarose gel electrophoresis and DNA sequencing analysis indicated that the target sequences were efficiently amplified by the PCR assay (550 bp for P. canaliculata, 405 bp for A. cantonensis). The minimum detectable level was 120 pg/microl. The coincidence between the two methods stood for 84.3% (145/172), including 45 positives and 100 negatives. 24 snails were PCR positive and microscopy negative, 3 snails were PCR negative and microscopy positive. The sensitivity and specificity of multiplex PCR was 93.8% and 80.6%, respectively. Its positive rate (40.1%, 69/172) was significant higher than that of lung-microscopy (27.9%, 48/172)(chi2 = 14.8, P < 0.01). A multiplex PCR method has been developed for the detection of A. cantonensis larvae in P. canaliculata.

Xu J.F.,National Institute of Parasitic Diseases
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases | Year: 2011

With the development of information technology, artificial neural networks has been applied to many research fields. Due to the special features such as nonlinearity, self-adaptation, and parallel processing, artificial neural networks are applied in medicine and biology. This review summarizes the application of artificial neural networks in the relative factors, prediction and diagnosis of infectious diseases in recent years.

Chen C.,National Institute of Parasitic Diseases
Infectious Diseases of Poverty | Year: 2014

This historical review covers antimalarials developed in China, which include artemisinin, artemether, artesunate, and dihydroartemisinin, as well as other synthetic drugs such as piperaquine, pyronaridine, benflumetol (lumefantrine), and naphthoquine. The curative effects of these antimalarials in the treatment of falciparum malaria, including chloroquine-resistant strain, are especially discussed. Following the World Health Organization (WHO) recommended artemisinin-based combination therapy (ACT), different combinations of artemisinin, or its derivative, along with another antimalarial drug were orally used to treat Plasmodium falciparum infections. The recrudescence rates were low, gametocyte carriers lessened, and the curative rate increased remarkably. The combination therapy effectively deferred the emergence of drug resistance in the parasite. The regulation "The guidelines and regimens for the use of antimalarial drugs in China" was issued to guide rational application and standardize malaria treatment in the country. As the recommended first-line drug to treat falciparum malaria in the world, ACT was adopted in the regulation. In response to the global initiative of malaria eradication proposed by the UN Millennium Development Goals (MDGs), the Chinese government has set a target to eliminate malaria by 2020. © 2014 Chen; licensee BioMed Central Ltd.

Liu D.-Q.,National Institute of Parasitic Diseases
Infectious Diseases of Poverty | Year: 2014

Since the successful preparation of the microplates and the medium for field application, the resistance degree and its geographical distribution of chloroquine-resistant Plasmodium falciparum, the fluctuation of the resistance degree of P. falciparum to chloroquine, and the sensitivity of the parasite to commonly used antimalarial drugs were investigated between 1980 and 2003 by the in vitro microtest and the in vivo four-week test recommended by the World Health Organization (WHO). The results indicated that chloroquine-resistant falciparum malaria was present in all eight provinces/autonomous regions endemic for falciparum malaria in China, and the resistance was high and widely distributed in the Hainan and Yunnan provinces. When the use of chloroquine was stopped or administered in a decreased quanity, the drug resistance gradually decreased. In Hainan and Yunnan, P. falciparum was still highly resistant to chloroquine, amodiaquine and piperaquine, and sensitive to pyronaridine and artemisinin derivatives, but the sensitivity was gradually reduced. Based on these results, principles and therapeutic regimens for antimalarial drug use in China were formulated, the use of the antimalarials which had already developed resistance was stopped or reduced, and recommendations to use artemisinin derivatives or compound pyronaridine to promote a rational use of antimalarials and strengthen malaria control were made. The results showed that malaria incidence had declined, and endemic areas of falciparum malaria have been gradually reducing since the mid-1980s. © 2014 LIU; licensee BioMed Central Ltd.

Chen M.-G.,National Institute of Parasitic Diseases | Chen M.-G.,Collaborative Center for Malaria
Infectious Diseases of Poverty | Year: 2014

This paper presents a historical assessment of morbidity due to the Schistosoma japonicum infection in China. Due to the socio-economic situation, which did not allow for a control program to be implemented until the early 1950s, morbidity was serious and mortality was high before this. Based on a few investigations and published papers, it can be said that the disease caused millions of deaths, and destroyed numerous families and villages. Since the 1950s, there has been a national control program, intensive control and prevention work has been carried out, and consequently the disease is being controlled. At present, both the prevalence and the morbidity of the disease have been decreasing substantially. The morbidity of the three phases of the disease is outlined in this paper. Comparatively higher morbidity is seen in the acute and advanced phases of the disease. The four major forms of advanced schistosomiasis i.e., ascites, megalosplenia, dwarfism, and colonic tumoroid proliferation, are outlined with their characteristic clinical presentations; their proportions are different during various periods of the national control program. Ectopic schistosomiasis and the relationship between the S. japonicum infection and colorectal cancer are also discussed. Post-transmission schistosomiasis is briefly discussed (which can happen even if the disease reaches the criteria of elimination, and the infection and transmission have stopped, but yet it still develops). The problem of mammalian reservoir hosts of S. japonicum makes the epidemiology and control of schistosomiasis in China even more complicated and arduous, and the control progress in animal reservoirs is briefly presented. © 2014 Chen; licensee BioMed Central Ltd.

Xu L.L.,National Institute of Parasitic Diseases
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases | Year: 2011

To observe the in vitro effect of praziquantel, tribendimidine, levamisole, artemether, artesunate, albendazole and mebendazole against adult Clonorchis sinensis. Seventy rats infected with 50-100 C. sinensis metacercariae for 5-7 weeks were euthanized, and adult C. sinensis were collected from the common bile duct Three to four worms were placed in each well of a 24-well falcon plate, and treated by Hanks' balanced salt solution-20% calf serum containing aforementioned drugs at various concentrations. The motor activity and morphology change of the worms were observed under an inverted microscope at 4, 24, 48 and 72 h post treatment. Praziquantel could reduce the motor activity of the worms rapidly which resulted in detachment of oral sucker from the well wall, curl of the worm body and emergence of vacuoles from the tegument. The minimal concentration of praziquantel to kill adult C. sinensis was 0.1 g/ml. After adult C. sinensis exposed to tribendimidine at concentrations of 0.5, 1 and 10 g/ml, they revealed in paralysis, looseness and stretch of the worm body rapidly or immediately. The minimal concentration of tribendimidine to kill adult worms was 0.05 g/ml. When worms exposed to levamisole at 10 and 20 g/ml, there was a gradual decrease in the worm's motor activity accompanied by looseness of the worm body. But 48 h post exposure, most worms showed apparently recovery of motor activity. In a higher levamisole concentration of 50 g/ml, all worms revealed in stretch and paralysis which was similar to that induced by tribendimidine. When adult C. sinensis were exposed to artemether or artesunate 10 and 50 g/ml, the motor activity of worm body and oral sucker reduced which accompanied by worm contraction, then followed by looseness of the worm body and emergence of vacuoles along the tegument. At 72h post exposure, the worm mortalities induced by the two concentrations of the two drugs were about half, respectively. In adult C. sinensis exposed to albendazole and mebendazole at concentrations of 10 and 50 g/ml, only stimulation of motor activity of oral sucker was seen which revealed in vigorous contraction within 24 h post exposure. During 72 h observation period, no any other changes in worm activity and morphology were seen. Praziquantel and tribendimidine exhibit strong in vitro killing effect on adult C. sinensis. The minimal concentration of levamisole used to kill adult worm is 50 times higher than that of tribendimidine. The higher concentrations of artemether and artesunate show slower action to reduce the worm activity and kill part of the worms. Higher concentrations of albendazole and mebendazole exhibit no killing effect on C. sinensis, besides stimulating the motor activity of worm oral sucker.

Pan J.Y.,National Institute of Parasitic Diseases
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases | Year: 2012

To investigate the impact of the application of chemical pesticides on the distribution of Anopheles anthropophagus in rice fields and the malaria incidence. Twenty-four villages from 16 counties in the provinces of Zhejiang, Sichuan and Guangxi were chosen for the surveys in the period of 1983-1987. For the survey of An. anthropophagus, indoor human bait trapping until midnight and catching the mosquitoes in all the nets in early morning were carried out to get the density and population ratio of the mosquitoes. Historical data on Anopheles spp., malaria incidence, acreage of the single or double season cropping of rice and on the quantity of chemical pesticide used in rice fields were collected from the study areas. In Hang-jia-hu region of Zhejiang Province, double season rice cropping was performed at that time, the quantity of pesticides used in 1973 was 45 kg/hm2, which was as high as 50 times than that in the 1950s. The density of An. anthropophagus decreased yearly, no An. anthropophagus could be found at 11 survey points in late 1980s. The malaria incidence dropped to less than 1 per 10000. In Leshan and Yibin areas of Sichuan Province, the major cultivation was single cropping, pesticides were applied in paddy fields since 1960s, and the average quantity of pesticides used was 8.6 kg/hm2 during 1970s-1980s. No significant difference on the density of An. anthropophagus was revealed between 1980s (86.2%) and 1960s (82.2%) (chi2=0.63, P>0.05). After mid-1980s, pesticide use gradually increased, and reached to 18.18 kg/hm2 in average in the years after 2000. The density of An. anthropophagus decreased, no An. anthropophagus was found in 2010 in the area surveyed and no malaria cases were reported as well. With double season cropping in Huanjiang County of Guangxi, the pesticide amount consumed was 1.79kg/hm2, 25.13 kg/hm2 and 7.68 kg/hm2 in paddy fields in 1960s, 1970s, and 1980s, respectively. The proportion of An. anthropophagus in anophelines was 52%(1 747/3 392) in the beginning of the 1980s. After the year 2000, the average pesticide use increased to 20.38 kg/hm2 in paddy fields. It was difficult to find An. anthropophagus in human dwellings after 2008. The average annual malaria incidence dropped to 0.14 per 10 000. Change of farming activities and especially use of chemical pesticides in high quantity at the rice fields undermine the breeding environments of An. anthropophagus, greatly reduce the mosquito population and therefore the malaria incidence.

Xiao S.H.,National Institute of Parasitic Diseases
Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology & parasitic diseases | Year: 2010

OBJECTIVE: To observe the effect of mefloquine on the tegument of adult Schistosoma japonicum harbored in mice. METHODS: Twelve mice were each infected with 60-80 S. japonicum cercariae. At 35 days post-infection, 10 mice were treated orally with mefloquine at a single dose of 400 mg/kg. Two mice were sacrificed at 8 h, 24 h, 3 days, 7 days, and 14 days post-treatment respectively, and schistosomes were collected by the perfusion technique, fixed and examined under a scanning electron microscope. Schistosomes obtained from the remaining 2 untreated mice served as control. RESULTS: 8 h post-treatment, male and female schistosomes showed focal swelling of the worm body accompanied by extensive swelling, tough junction and fusion of tegumental ridges. Meanwhile, some of the sensory structures showed enlargement and part of them collapsed. 24 h after mefloquine administration, head portion of some male and female worms revealed high swelling accompanied by severe damage to oral sucker. 3 days post-treatment, focal swelling of worm body along the whole worm was universal. In some male and female worms, the damaged tegument fused together to form a large mass protruding from the tegumental surface. In addition, focal or extensive peeling of tegumental ridges was seen or collapse of enlarged sensory structure resulted in formation of hole-like appearance. 7 days post administration, focal swelling of worm body and damage to tegument induced by mefloquine were similar to those aforementioned, but focal peeling, collapse of enlarged sensory structures, and deformation of oral sucker in male and female worms were universal. 14 days post-treatment, individual male worm survived the treatment revealed normal appearance of tegumental ridges in head portion, although light focal swelling of worm body was still observed. CONCLUSION: Mefloquine causes focal swelling of worm body, extensive and severe damage to the tegument in adult S. japonicum.

Xiao S.-H.,National Institute of Parasitic Diseases
Parasitology Research | Year: 2013

Up to date, schistosomiasis is still prevalent worldwide. It is estimated that more than 200 million individuals are infected, and 120 million suffer from clinical morbidity. Facing such huge cases of schistosomiasis, only heavy reliance on a single praziquantel for schistosomiasis control does not adapt and may promote the selection and spread of drug-resistant parasites. Therefore, it is an urgent need to develop the new antischistosomal drug. In 2008-2009, the antimalarial drug mefloquine, an arylaminoalcohol compound, has been found to be effective against schistosomes. According to the experimental studies, the deepest impression on the antischistosomal properties of mefloquine can be summarized as following points: (1) single dose of mefloquine possesses potential effect against three major species of schistosomes (Schistosoma mansoni, Schistosoma haematobium, and Schistosoma japonicum) infecting humans; (2) the drug displays similar effects against developing stages of juvenile and adult schistosomes, which are superior to that of artemisinins and praziquantel; (3) in vitro mefloquine exerts direct killing effect on juvenile and adult schistosomes, while in vivo, the efficacy of the drug is independent to host immune response, (4) mefloquine causes extensive and severe morphological, histopathological, and ultrastructural damage to adult and juvenile schistosomes, particularly, the worm tegument, musculature, gut, and vitelline glands of female worms are the key sites attacked by the drug; (5) combined treatment with mefloquine and praziquantel, or artemisinins shows synergistic effect against schistosome in experimental therapy,while in initially clinical trial, mefloquine in combination with artesunate also exhibits higher cure rates against schistosomiasis hematobia and schistosomiasis mansoni, and (6) several mefloquine-related arylmethanols exhibit potential effect against schistosomes in vivo, which is a useful clue helpful for development of new antischistosomal compound. In the present review, we have summarized the major results published in recent years, and the significance as well as the prospect for the future study of mefloquine have been discussed briefly. © 2013 Springer-Verlag Berlin Heidelberg.

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