Objective To analyzed the genetic diversity, genetic differences between populations and differentiation time of Echinococcus granulosus and E. multilocularis of Qinghai isolates, in order to provide scientific basis for species tracing and prevention and control of Echinococcus in Qinghai Province, China. Methods For genetic analysis, 50 liver lesion samples were collected from hospitalized echinococcosis patients in the Affiliated Hospital of Qinghai University to extract genomic DNA and amplify mitochondrial dehydrogenase 1 gene (nad1). Sequence multiple alignment was performed using Clustal X v2.0 software. Geographic informatics mapping of patients’ residence was constructed using ArcGIS software. Sequence haplotype analysis was made with DnaSP v6 software. Modeltest 3.7 software and PAUP*4.0B10 software were used to calculate the minimum optimal nucleic acid evolution model. The Bayesian’s phylogenetic evolution tree was constructed with MrBayes-3.2.7 software. The differentiation time of each node in the phylogenetic tree was estimated with the Bayesian method using BEAST v2.6.3 software. Results We successfully identified 48 Echinococcus lesion samples specimen and obtained the full length of complete nad1 gene of 894 bp. Among them, 13 samples were identified as the G1 genotype of E. granulosus, and 35 samples as E. multilocularis. All the sequences showed > 99% similarity to those in GenBank. Four haplotypes were identified as H1-H4 in the two species respectively; H3 was the dominant haplotype in E. granulosus samples(10/13), which is present in Xining, Guoluo, Yushu, Haidong, Haibei and Huangnan. H2 haplotype was found dominant in E. multilocular samples (51.4%,18/35), which is present in Xining, Guoluo, Yushu, and Haidong. The phylogenetic tree showed that E. granulosus and G1 genotype clustered into one branch, and E. multilocularis and Asian strain clustered into one branch. The results of differentiation time showed that the nearest common ancestor of E. granulosus, E. multilocularis, E. vogeli and E. oligarthrus was about 5.5 Mya (95% confidence interval 4.5-6.5 Mya), and the differentiation time of E. granulosus and E. multilocularis was about 2.5 Mya (95% confidence interval 2.3-4.1 Mya). Conclusion Both human E. granulosus and E. multilocularis in Qinghai Province show high genetic diversity. E. granulosus was found of G1 genotype, with H3 as the dominant haplotype, while in E. multilocularis samles H2 is the dominant. The two speies are widely distributed throughout Qinghai Province. The two species of Echinococcus exhit closer genetic relationship and differentiation timing.

The paper includes a comprehensive review of the present status of kala-azar in China and the advances in relevant investigations and studies since I960. The disease was practically eradicated in most of the endemic areas in 1958 by means of mass treatment, sandfly control and destruction of infected dogs in areas with prevalence of canine leishma-niasis. Through relentless and sustained efforts in the control of the disease, no more fresh cases of kala-azar occurred in the provinces of Shandong, Jiangsu, Anhui, Henan, Hebei and Eastern Shaanxi over the past decade. In the meantime, the density of sandfly vector, Phlebotomus chinensis was greatly reduced, and in many villages completely eliminated. The results of leishmanin dermal test are all negative among the people under 15 years of age. During the last three years, only a few sporadic cases have been reported from the mountainous and desert areas in the northwest, including Xinjiang, Gansu, northern Shaanxi, Nei Mongol, Shanxi and Sichuan. Since 1964, epidemiological investigations have suggested the existence of natural nidus of visceral leishmaniasis in the deserts of Xinjiang and Nei Mongol, with Phlebotomus major wui as the vector. A large number of wild animals have been examined, but so far the reservoir hosts have net yet been ascertained. In addition, studies on epidemiology, sandfly vectors, special clinical manifestations and immunodiagnosis of kala-azar have been made with much progress. For ultimate control of kala-azar in China, suggestions are put forward on further control measures and research work.

A retrospective survey on side-effects for pyquiton was made among 25,693 cases of schistosomiasis japonica treated in Jiangsu, Zhejiang, Anhui, Jiangxi Provinces and Shanghai Municipality. Teams were sent separately to the fields for on-the-spot investigation which included briefings and meetings with local medical workers responsible for pyquiton treatment, reviewing of case records, visiting to the patients when necessary and filling of a unified survey questionnaire prepared beforehand.Apart from 500 acute cases, 1,175 advanced cases and 10 cases of cerebral schistosomiasis, the majority were chronic cases. The main dose-schedule used was the 2-day pyquiton regime with a total dose of 60mg/kg (70mg/kg for children).It was supported by findings during the field survey, and agreed upon unanimously by all medical workers that pyquiton was definitely the drug of the first choice in treating schistosomiasis on account of its high efficacy and low toxicity. However, some comparatively serious side-effects did happen though with very low incidence, which included syncope (14 cases), psychotic disorder (5), relapse of schizophrenia (6), hysteria (3), epileptic s izures (8), flaccid paralysis in lower limbs (2), ataxia (1), frequent premature beats (22), auricular fibrillation (3), heart rate below 50 per minute (4), supraventricular paroxysmal tachycardia (2), first degree atrioventricular block (5), attacks of angina pectoris (1), jaundice (2), hepatic coma in advanced cases with ascites (2), serious skin rashes (18) and some delayed reactions (29). However, most of the side-effects were transient and reversible and no fatality was directly associated with the drug.

This article deals with the determination of specific IgG, IgM and IgE to soluble egg antigen in schistosomiasis japonica to assess the therapeutic efficacy of antischistosomal drugs. It was found that 97.6% of the proved cases were positive by ELISA, while all of the sixty-five patients other than schistosomiasis were negative. Follow-up stool examinations of 131 patients for 6-8 months showed that 117 cases (89.3%) turned negative after pyquiton treatment, and 80.3% of the cases also revealed IgM negative. In this context, IgM negatives following chemotherapy of schistosomiasis meant an effective treatment. 48 out of 50 cases showed comparable results after simultaneous capillary and venous blood samples, so capillary method turned out to be one of the choices in field studies.

The present paper reports on the result of an experimental study on the susceptibility of A. minimus and A. dims to two human Plasmodia: P. vivax and P. falciparum. 11 lots of A. minimus and A. dims were allowed to feed in vitro on the blood from 11 vivax malaria patients, and the feeding of the two species of mosquitoes was carried out simultaneously on one sample of blood. 10 lots of A. minimus became infected, the average gut and gland infection rate being 83.5% and 81.3% respectively, and the positive gland index 3.70. 11 lots of A. dims were all found infected, with an average gut infection rate of 88.2%, gland infection rate of 81.6% and a positive gland index of 2.98. Both species of the anophelines were shown to be highly susceptible to P vivax. So far as the gut and the gland infection rate was concerned, there was no significant difference in susceptibility between them. Although in most cases the number of oocysts on the stomach wall of A. dints apparently exceeded that of A. minimus, the mean diameter of differentiated oocysts of the latter was markedly larger and the intensity of the gland infection much higher. This probably indicated that A. minimus was a more appropriate host than A. dirus for the completion of the development of sporogonic cycle of P. vivax.Four lots of A. minimus and A. dirus were allowed to feed on the blood from 4 falciparum malaria patients. Three were successfully infected. The average gut infection rate of A. minimus and A. dirus was 65.8% and 66.2%, the oocyst index being 8.8 and 10.3 respectively; the average gland infection rate was 49.0% and 53.9%, and the positive gland index 2.31 and 2.46 respectively. These results showed high susceptibility to P. falciparum of the two anopheline species without any significant difference.The present study has experimently proved the high susceptibility of A. minimus to P. vivax and confirmed that in the mountainous areas of south China A. minimus is an important vector of the tertian malaria as well.

This report presents the effect of three antimalarial agents-chloroquine, piperaquine and hydroxypiperaquine-upon asexual erythrocytic forms of Plasmodium falciparum. An in vitro microtechnique was employed to assess the effect exerted on a strain of chloroquine-resistant P. falciparum (Cambodian I strain) compared with that on a strain of chloroquine sensitive P. falciparum (FCC-l/HN strain). The ED50 of chloroquine, piperaquine and hydroxypiperaquine against sensitive strain were 81, 59 and 56nM respectively after 48 hours cultivation, while the ED50 of these drugs against resistant strain were 563, 61 and 60nM respectively. The results obtained showed that the Cambodian strain was a 7-fold chloroquine-resistant strain and hadn't any significant cross resistance to piperaquine or hydroxypiperaquine. However, the resistance of this strain was unstable. Following in vitro cultivation without stimulation of chloroquine for 17 days, the degree of resistance decreased from 7 to 3.4 fold.

The chromosomes of salivary glands of Anopheles sinensis from Zhengzhou (Henan), Shanghai and Youxi (Fujian) districts were studied in 1979-1982 to detect their subspecies classification.The main differences among the gland chromosomes of the 4th instar larvae in these three districts were on the free ends of 2R besides tiny changes on each arm.The characteristics of chromosomes in Youxi was more identical with those in Shanghai than in Zhengzhou. It is seemingly due to the geographical variation.X chromosomes of Anopheles sinensis in these three districts were basically similar one to another, but they vary in position, size and component, especially in the puff position.Compared with Anopheles sinensis from Nanjing, the variance among salivary gland chromosomes of Anopheles sinensis 4th instar larvae renders another evidence of chromosomal polymorphism in the biological world as a whole.

The papillae of the head and tail of Ascoris lumbricoides were viewed by scanning electron microscope.En face view of the head shows three lips, one dorsal and two subventral lips. There are six internal labial papillae near the top of three lips, forming an inner labial papillar circle. Two dorsal, one ventral and one lateral papillae together with an amphid form the outer labial papillar circle.The dorsal papillae, are mounded elliptic elevations, showing a wide ventral and narrow dorsal side in shape. The ventral papillae have nearly the same size and shape as the dorsal papillae except that they show a wider dorsal and narrower ventral side. In the anterior dorsal region of the ventral papilla there is a lateral papilla and an amphid on the subventral lips. The ratio of distance between ventral papilla to lateral papilla and that between lateral papilla to amphid is 2-3:1.Precloacal papillae are arranged into two lines situated at each side before the cloaca. On one side, the beginning has 4-5 papillae arranged in a line, bifurcating later into two irregular lines. All of them appear to be a single elevation which has a mammilliform process located at the top of these papillae. There is a precloacal central papilla just at the anterior end of the cloacal lip. It is a typical double papilla.Postcloacaly, at one side, the anterior two form a pair of double papillae, the second one being smaller than the first. A round phasmidial pore is just located at the lateral side behind the second double one.It is suggested that the lips are joined two by two, i.e, the two original dorsal ones make up the dorsal lip, the four original lateral and ventral ones make up the two subventrai lips. The ventral papillae are two stalked structures, each original ventral cephalic papilla migrates anteriorly to the labial region and combines with the original outer labial papillae to form the ventral papillae. Similarly, the original outer labial and cephalic papilla at the dorsal side combine with each other to form the dorsal papilla.No obvious difference in shape and distribution of the labial papillae is found between the two species of Ascaris from man and pigs, except that the beginning of precloacal papillae arranged in a line is different. The number of these papillae in Ascaris suum is 6-7 usually, whereas that in Ascaris lumbricoides is 4-5.

A strain of axenic Naegleria fowleri was proliferated massively in Chang's medium and was introduced 'intranasally into 3 mice which were closely observed for 2-3 weeks. On the 13th day mouse 1 developed primary amoebic meningoencephalitis (PAME) symptoms, but mouse 2 had no signs of PAME at all at that time. On the 19th day, mouse 3 developed the same symptoms as mouse 1. Mice 1,2 and 4 were killed and autopsied for pathological examination. Mouse 3 was fixed in toto to keep the spasmodic posture.According to the typical manifestation, pathological findings and etiological characteristics, these mice were proved to be suitable models of Naegleria fowleri PAME.

Achievements for schistosomiasis control have been gained by implementation of integrated control strategies according to local conditions since the founding of the People′s Republic of China. By the end of 2008, 5 of the 12 provinces reached the criteria of transmission interruption. Among 454 endemic counties, transmission was interrupted in 265 counties while 97 counties reached the criteria of transmission control. The number of schistosomiasis cases decreased from 10 million in history to 413 000. Currently, there still left 92 counties where the disease is endemic and mainly distributed in lake and mountainous regions. Limited by the environmental and socio-economic factors, integrated control strategies could not be carried out in these places. Although the strategies based on reducing the roles of humans and cattle as resources of infection decreased the infection rate and intensity quickly, re-infection occurred frequently due to the spread of snails and numerous animal reservoirs. Chemotherapy alone could not interrupt the transmission. By changing the traditional biomedical control model, applying integrated control strategy mainly with social measures, integrating disease control with local social and economic development programs, changing the traditional life styles and agricultural production patterns, and eliminating the risk factors for schistosmiasis transmission, schistosomiasis control can be developed sustainably and reach the criteria of transmission interruption finally.

Studies were undertaken in 32 Oncomelania Snail-infected canal sections in Lumu Commune of Wuxian County in 1980. The results showed that the snail density in each canal section determined in the first survey was parallel to the total population of that section. There was a linear positive correlation between the snail density detected in the first survey and the density of the total snail population. However in low snail popular tion (below 0.7/square Chinese foot) area, snails may not be detected in the first survey. Results also showed that a linear positive correlation existed between the density of the snail eggs and the density of the total snail population.

To understand the Anisakis larvae infection status in marine fishes sold in Shanghai, the fresh marine fishes caught in the East China Sea area were collected from Farmers’ markets, supermarkets and seafood markets in Shanghai in 2022. The suspected Anisakis larvae were searched in the offal and muscles after dissection and observed under optical microscope and scanning electron microscope, respectively. A total of 338 marine fish of 16 species were collected, and 1 065 Anisakis larvae were found from 116 fish of 6 species, with a total infection rate of 34.3% (116/338) and average infection intensity of 9.2 larvae/fish. The highest infection rate was 11/12 in Lophiiformes, and the highest average infection intensity was 13.0 larvae/fish in Larimichthys polyactis. The Anisakis larvae infection rates increased gradually from spring to winter. The infection rate and average infection intensity in winter were 51.1% (46/90) and 12.3 larvae/fish, respectively, which were the highest seasons of the year. The predominant sites of Anisakis larvae parasitise in marine fishes were the intestines and abdominal cavity, with infection rates of 54.6% (582/1 065) and 40.7% (433/1 065), respectively. The result showed that Anisakis larvae infections were present in marine fish sold in Shanghai and the infection rates of commonly consumed marine fishes such as Lophiiformes and L. polyactis were high.