[Amiota magna as an intermediate host of Thelazia callipaeda under laboratory conditions].

A number of flies around the eyes of a person or around a fruit bait were collected from Huangshan Mountain, and experimentally infected by newborn larvae of Thelazia callipaeda. After 20 days, the flies were examined for T. callipaeda. Following dissection, 3 (30%, 3/10) of Amiota magna, and 55 (21.6%, 55/255) of A. okada were found infected by T. callipaeda. The susceptibility of T. callipaeda is similar in the two species fruit flies (chi2=0.0584, P> 0.05). The rabbits were infected by infective larvae of T. callipaeda from A. magna. At the 35th day after infection, the newborn larvae and worms of T. callipaeda were found in the conjunctival sac of rabbits. This study suggested that A. magna acts as intermediate host of T. callipaeda under laboratory conditions.

Population structure analysis of the neglected parasite Thelazia callipaeda revealed high genetic diversity in Eastern Asia isolates.

BACKGROUND: Thelazia callipaeda is the causative agent of thelaziasis in canids, felids and humans. However, the population genetic structure regarding this parasite remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we first explored the genetic variation of 32 T. callipaeda clinical isolates using the following multi-molecular markers: cox1, cytb, 12S rDNA, ITS1 and 18S rDNA. The isolates were collected from 13 patients from 11 geographical locations in China. Next, the population structure of T. callipaeda from Europe and other Asian countries was analyzed using the cox1 sequences collected during this study and from the GenBank database. In general, the Chinese clinical isolates of T. callipaeda expressed high genetic diversity. Based on the cox1 gene, a total of 21 haplotypes were identified. One only circulated in European countries (Hap1), while the other 20 haplotypes were dispersed in Korea, Japan and China. There were five nucleotide positions in the cox1 sequences that were confirmed as invariable among individuals from Europe and Asia, but the sequences were distinct between these two regions. Population differences between Europe and Asian countries were greater than those among China, Korea and Japan. The T. callipaeda populations from Europe and Asia should be divided into two separate sub-populations. These two groups started to diverge during the middle Pleistocene. Neutrality tests, mismatch distribution and Bayesian skyline plot (BSP) analysis all rejected possible population expansion of T. callipaeda. CONCLUSIONS: The Asian population of T. callipaeda has a high level of genetic diversity, but further studies should be performed to explore the biology, ecology and epidemiology of T. callipaeda.

[An update on the research of human thelaziosis].

Thelaziosis is one of the parasitic zoonoses which affects the eyes of humans and domestic animals. This review covers its distribution, morphology and life cycle of the parasite, pathogenesis, clinical diagnosis, treatment, and prevention of the disease.

Elevated plasma tissue-type plasminogen activator (t-PA) and soluble thrombomodulin in patients suffering from severe acute respiratory syndrome (SARS) as a possible index for prognosis and treatment strategy.

OBJECTIVE: To detect the presence of endothelial injury in patients with severe acute respiratory syndrome (SARS) via enhanced levels of tissue-type plasminogen activator (t-PA) and soluble thrombomodulin (sTM). METHODS: Case patients were from Xuanwu Hospital (Capital University of Medical Sciences, Beijing, China), and all of them met clinical criteria for SARS. Healthy controls were some of the hospital employees. Endothelial injury bio-markers tPA and sTM were detected by commercial ELISA-methods. RESULTS: Classic plasma markers of endothelial injury, tPA and sTM significantly elevated in SARS patients in comparison to controls [t-PA: 1.48 +/- 0.16 nmol/L versus 0.25 +/- 0.03 nmol/L (P<0.0001), and sTM: 0.26 +/- 0.06 nmol/L versus 0.14 +/- 0.02 nmol/L (P<0.05)]. The only patient who died had extremely high levels of these endothelial injury markers (t-PA: 2.77 nmol/L and sTM: 1.01 nmol/L). The likelihood ratio analysis indicated the excellent discriminating power for SARS at the optimal cut-point of 0.49 nmol/L for tPA and 0.20 nmol/L for sTM, respectively. Significant numerical correlations were found among these endothelial injury markers in SARS patients. The numerical coefficient of correlation Pearson r between t-PA and sTM was 0.5867 (P<0.05). CONCLUSION: Increased plasma concentrations of tPA and sTM in patients with SARS suggest the possibility of endothelial injury. SARS patients might need anticoagulant therapy or fibrinolytic therapy in order to reverse intraalveolar coagulation, microthrombi formation, alveolar and interstitial fibrin deposition. It may not only provide a useful treatment and prognostic index but also allow a further understanding of the pathological condition of the disease.

[The study of human rhinovirus in infants with lower respiratory tract infections].

OBJECTIVE: We want to explore the harm degree of human rhinovirus in infants in Beijing area. METHODS: From May 2008 to September 2009, 240 nasopharyngeal aspirates were collected from the children and infants who were hospitalized and with lower respiratory tract infections. These specimens were screened for HRV by real-time reverse transcription PCR (RT-PCR) and statistically analysised. RESULT: In all of 240 hospitalized children, 208 cases were admission diagnosis of pneumonia, accounting for 86.67% (208/240), no deaths, the ratio of male and female patients was 1.93 : 1, and the collected samples reached to a maximum number in February 2009. Real-time PCR used to detect human rhinovirus, positive samples number is 71, positive rate is 29.58% (71/240), and the main symptoms and clinical diagnosis was pneumonia. Most cases were less than 2 years old, making up 81.69% (58/71), amony them, 13 months-18 months age and > or = 24 months groups have the highest incidence rates, the incidence rate is 33.33%. CONCLUSION: Human rhinovirus happened in spring and winter seasons, especially the infants who were under 2 years are the main infection groups, the important symptoms are lower respiratory infections such as pneumonia, bronchitis and bronchiolitis et al. Human rhinovirus is seasonal and contagious, spreads fast, so protective measures in hospitals should be prepared to avoid cross-infection.

[Longitudinal investigation and experimental studies on thelaziasis and the intermediate host of Thelazia callipaeda in Guanghua county of Hubei province].

OBJECTIVE: To verify houseflies Musca spp. as the intermediate host of Thelazia callipaeda and reveal epidemiological situation of thelaziasis in Hubei province. METHODS: Dogs eyes infected with T. callipaeda, 400 houseflies Musca and 259 fruitflies Amiota okadai in the city of Laohekou city (previously named as Guanghua county) of Hubei province had been investigated since September 2000. The newborn larvae of T. callipaeda from Laohekou suburbs were fed to houseflies Musca and A. okadai. Larvae used for the study were isolated from female T. callipaeda in laboratory and the susceptibility to houseflies Musca and A. okadai was observed. RESULTS: Twenty-one dogs from Laohekou, the original epidemic areas of thelaziasis were examined and 7 positive dogs in 21 (33.3%) and 11 T. callipaeda (9 females and 2 males) were identified. From 1975 to 2000, no thelaziasis cases were found through retrospective surveys. These 200 houseflies Musca and 135 A. okadai were dissected for examination but showed all negative with the infection. However, newborn larvae of T. callipaeda were used to experimentally infect 112 houseflies Musca and 84 A. okadai and all infected flies were examined on the 20th day after inoculation. As a consequence, houseflies Musca failed to be infected but 9 in 84 (10.7%) A. okadai were positive. 26 infective larvae of T. callipaeda were obtained and 21 of them were inoculated into right eye of one rabbit. The female worm began to produce newborn larvae in 37 days after infection and 3 adult T. callipaeda (two females and one male) were obtained. CONCLUSIONS: Fruitflies A. okadai from Hubei province were susceptible to T. callipaeda, which was similar to the result of experimental studies in Anhui province. This survey further confirmed that A. okadai was the intermediate host of T. callipaeda but not houseflies Musca. Infective resources (adult dogs, for instance) had been under controlled thus human thelaziasis had been eradicated in this rural area.