[Assessment of malaria knowledge and capability on Plasmodium detection among professionals from class III malaria-endemic counties of Henan Province in 2012].

OBJECTIVE: To evaluate the capability of malaria parasite detection among professionals from Class III malaria endemic counties of Henan Province in 2012. METHEDS: The capacity assessment of professionals from the Centres for Disease Control and the medical institutions was done in September to December 2012. The content of the assessment included malaria knowledge (including malaria etiology, clinical manifestation, diagnosis, treatment and epidemiology and so on, 100 scores as full marks and 60 as passing score), making blood slides of Plasmodium (4 slides in 1 hour, including Giemsa staining, 40 scores as full marks and 24 as passing score) and identification of species with microscopy (6 slides, 8 min per slide 60 scores as full marks and 36 as passing score). All the participanats were grouped by gender, age, professional title, level and type of institution. Their scores were statistically analyzed by SSPS 17.0 software. RESULTS: The average total score in 891 participants was 162.1, the highest was 200 (full markers), and the lowest was 96, and 871 (97.8%) participants passed the test (> or = 120 scores). There were no significant differences for the scores of blood slide making among gender, age, professional title and level of institution (P > 0.05). No significant differences in the scores of malaria knowledge and blood slide reading among gender female participants (162.97 +/- 17.64) was higher than that of males (159.01 +/- 20.33) (P < 0.05). The film-reading and total scores of 50-plus age group (34.62 +/- 14.82, 144.62 +/- 20.33) was significantly lower than the other three groups (under age 30 group: 45.75 +/- 13.58 and 162.50 +/- 18.90, age 31-40 group: 46.53 +/- 12.72 and 163.51 +/- 17.77, age 41-50 group: 46.22 +/- 13.38 and 159.80 +/- 17.32) (P < 0.05). The scores of malaria knowledge in 50-plus age group (84.38 +/- 9.41) was lower than that of under age 30 group (89.91 +/- 7.81), age 31-40 group (89.96 +/- 7.74) (P < 0.05). The scores of malaria knowledge (88.33 +/- 8.23, 90.00 +/- 7.76, 92.37 +/- 7.29), film-reading (44.88 +/- 13.62, 46.59 +/- 12.88, 49.57 +/- 11.98) and total scores (159.61 +/- 18.37, 163.81 +/- 18.03, 169.15 +/- 16.38) of primary, intermediate and senior groups was proportional to the level of the titles, and the difference between the groups was statistically significant (P< 0.05). The theory (88.28 +/- 8.30, 90.84 +/- 7.32, 93.54 +/- 6.10), film-reading (44.54 +/- 13.14, 47.69 +/- 13.40, 52.62 +/- 11.04) and total scores (159.48 +/- 18.33, 165.92 +/- 17.31, 171.97 +/- 15.53) of the three institution level groups (township, county and province) were proportional to their level, and the difference between the groups was statistically significant (P < 0.05). There was no significant differences for the scores between the CDCs and hospitals (P < 0.05). CONCLUSION: The capabilities of malaria parasite detection in Class III malaria endemic counties of Henan Province is balanced. It needs to strengthen the skills training for the professionals of the junior, intermediate and primary care units.

[Polymorphism analysis on the genotypes of circumsporozoite protein of Plasmodium vivax with PRC-RFLP].

Thirty-seven blood samples from Plasmodium vivax-infected patients were collected in Henan Province in 2011. The gene for circumsporozoite protein (PvCSP) was amplified by nested PCR. According to the epidemiological data, among the 37 Plasmodium vivax malaria cases, 26 were indigenous cases and 11 were imported cases. A fragment of 750 bp was obtained in the 37 blood samples. The 750 bp PCR product was digested with restriction endonuclease Alu-I and Mva-I, and genetic polymorphism was investigated with PCR-RFLP. PCR-RFLP analysis of PvCSP revealed that the parasites were PV-I type (97.3%, 36/37) and PV-II type (2.7%, 1/37). 26 samples from indigenous cases were exclusively PV-I type with PV-I-b type (57.7%, 15/26) and PV-I-a type (42.3%, 11/26). Among 11 samples from imported cases, PV-I-a type accounted for 90.9% (10/11), and 1 PV-II type accounted for 9.1% (1/11), no PV-I-b type were detected.

[Laboratory detection on two cases with imported Plasmodium ovale infection].

OBJECTIVE: To compare the laboratory tests of the imported Plasmodium ovale infection and analyse the genetic character. METHODS: After Giemsa staining and microscopy, CareStart rapid detection and nested PCR were used to detect two cases with P. ovale infection returning from Congo (Brazzaville) in Henan Province. Sequencing was performed after PCR amplification using the 18S rRNA genus-specific primers. Their genetic characteristics were analyzed and the sequence homology analysis was performed in the NCBI. RESULTS: The two cases were confirmed as P. ovale infection by morphological examination microscopically. Amplified bands were produced by 18S rRNA nested PCR, which was the same with P. ovale in size, whereas the results of CareStart rapid detection test were all negative. A sequence of 906 bp in length was obtained by sequencing their 18S rRNA genes in which GC accounted for 35.4%, and the sequence showed 99% homology to the corresponding part of the known P. ovale 18S rRNA gene (GenBank accession No. AB182492). CONCLUSION: Both the nested PCR and microscopy confirm the infection of P. ovale. A negative result of CareStart rapid detection can not ruled out the Plasmodium infection.

[Molecular identification of Anopheles hyrcanus complex by using single enzyme digestion PCR-RFLP method].

OBJECTIVE: To establish a novel molecular identification method for discrimination of members within Anopheles hyrcanus complex. METHODS: The sequences of the ribosomal DNA second internal transcribed spacer (rDNA ITS2) region of An. hyrcanus complex, including An. anthropophagus, An. lesteri, An. sinesis and An. yatsushiroensisi were analyzed by using molecular biology software Vector NTI 9.0, and a specificity restriction enzyme was selected based on the restriction fragment length polymorphism. Thus the single enzyme digestion PCR-RFLP method was established for genetic identification of An. hyrcanus complex, and 452 anopheline mosquitoes captured in the field were tested, comparing with the results of the previously established double enzyme digestion PCR-RFLP method and traditional morphological classification. RESULTS: The molecular software analysis revealed that the restriction enzyme Dde I could digest rDNA ITS2 region of An. hyrcanus complex into different fragments, thus it could be used for single enzyme PCR-RFLP for An. hyrcanus complex identification, and the result was further confirmed by laboratory experiment. Furthermore, a total of 452 anopheline mosquitoes captured from 4 malaria endemic areas were tested by this single enzyme digestion PCR-RFLP method, and 20 of them were identified as An. anthropophagus, 6 as An. lesteri, 391 as An. sinesis, and 35 as An. yatsushiroensisi. The results were 100% accordant to the double enzyme digestion PCR-RFLP method, and 93.4% accordant to the traditional morphological classification. CONCLUSIONS: The newly established single enzyme digestion PCR-RFLP method can be used for An. hyrcanus complex identification, and is more simple and reliable than the traditional morphological classification, and it is a suitable tool for field entomology surveillance.

Vector capacity of Anopheles sinensis in malaria outbreak areas of central China.

BACKGROUND: Both falciparum and vivax malaria were historically prevalent in China with high incidence. With the control efforts, the annual incidence in the whole country has reduced to 0.0001% except in some areas in the southern borders after 2000. Despite this, the re-emergence or outbreak of malaria was unavoidable in central China during 2005-2007. In order to understand the role of the vector in the transmission of malaria during the outbreak period, the vector capacity of An. sinensis in Huanghuai valley of central China was investigated. FINDINGS: The study was undertaken in two sites, namely Huaiyuan county of Anhui province and Yongcheng county of Henan province. In each county, malaria cases were recorded for recent years, and transmission risk factors for each study village including anti-mosquito facilities and total number of livestock were recorded by visiting each household in the study sites. The specimens of mosquitoes were collected in two villages, and population density and species in each study site were recorded after the identification of different species, and the blood-fed mosquitoes were tested by ring precipitation test. Finally, various indicators were calculated to estimate vector capacity or dynamics, including mosquito biting rate (MBR), human blood index (HBI), and the parous rates (M). Finally, the vector capacity, as an important indicator of malaria transmission to predict the potential recurrence of malaria, was estimated and compared in each study site.About 93.0% of 80 households in Huaiyuan and 89.3% of 192 households in Yongcheng had anti-mosquito facilities. No cattle or pigs were found, only less than 10 sheep were found in each study village. A total of 94 and 107 Anopheles spp. mosquitos were captured in two study sites, respectively, and all of An. sinensis were morphologically identified. It was found that mosquito blood-feeding peak was between 9:00 pm and 12:00 pm. Man biting rate of An. sinensis was 6.0957 and 5.8621 (mosquitoes/people/night) estimated by using half-night human bait trap method and full-capture method, respectively. Human blood indexes (HBI) were 0.6667 (6/9) and 0.6429 (18/28), and man-biting habits were 0.2667 and 0.2572 in two sites, respectively. Therefore, the expectation of infective life and vector capacity of An. sinensis was 0.3649-0.4761 and 0.5502-0.7740, respectively, in Huanhuai valley of central China where the outbreak occurred, which is much higher than that in the previous years without malaria outbreak. CONCLUSIONS: This study suggests that vivax malaria outbreak in Huanhuai valley is highly related to the enhancement in vector capacity of An. sinensis for P. vivax, which is attributed to the local residents' habits and the remarkable drop in the number of large livestock leading to disappearance of traditional biological barriers.

[Epidemiological analysis of imported malaria in Henan Province in 2011].

OBJECTIVE: To analyze the epidemiological characteristics of imported malaria in Henan Province in 2011, and provide scientific basis for the control of imported malaria. METHODS: Data of imported malaria were collected and analyzed by SPSS11.5 in 2011. RESULTS: 145 imported malaria cases were reported. Among them, 110 (75.9%) were falciparum malaria, 31 (21.4%) were vivax malaria, 3 (2.1%) were quartan malaria, and 1 (0.7%) was ovale malaria. The ratio of males to females was 47.3:1 (142/3). The average age was (37.7 +/- 9.4) years old. 113 patients returned from Africa, accounted for 77.9% of the total. The main reason for going abroad among the cases was labor export (82.8%, 120/145). The cases were reported every month. The median interval from symptom appearing to diagnosis was 4 d, only 19 patients (13.1%) were diagnosed within 24 h. Eighty-six cases (63.2%) were reported by municipal medical units and CDC. Forty cases (29.4%) were reported by county level medical units and CDC. A total of 143 cases recovered with chemotherapy and two cases died. CONCLUSION: In order to avoid the death of malaria cases and reduce the risk of secondary transmission, malaria screening and health education for those returned from malaria-endemic areas should be strengthened and the diagnosis and treatment capabilities be improved at county medical units.

[Imported falciparum malaria situation in Henan Province during 2005-2009].

Imported falciparum malaria data of Henan Province in 2005-2009 were collected and statistically analyzed by using Microsoft Office Excel 2003. A total of 84 imported falciparum malaria cases with one death were reported during 2005-2009. The ratio of males to females was 20 : 1(80/4). The average age was (34 +/- 11) years old. Seventy-five patients returned from Africa, occupying 89.3%. The number of annual cases reported in 2008 (24 cases) and 2009 (32 cases) was higher than that in 2005-2007(9-10 cases). The top three high-risk populations were farmers (34 cases), workers (17 cases) and the cadre (13 cases), accounted for 76.2% of all cases. The cases were reported every month, of which 37 cases (44.0%) were reported in June and July. All cases had a history of prior residence in falciparum malaria endemic area, and the initial symptom was fever. The average interval from symptom appearing to diagnosis was (5.9 +/- 8.6) d, only 21.4% (18/84) of the patients was diagnosed within 24h. There were 72 laboratory-confirmed cases (85.7%). Seventeen cases (22.1%) were reported by county level medical treatment units. A total of 83 cases recovered with the treatment of artemisinin-based combination drugs. One case died with serious cerebral malaria. Effective measures should be carried to control the increasing trend of imported falciparum malaria.

[Evaluation on malaria situation in areas along Yellow River and Huaihe River by indirect fluorescent antibody test].

OBJECTIVE: To evaluate malaria situation by indirect fluorescent antibody test (IFAT) in 12 villages of six counties along Yellow River and Huihe River in Anhui, Henan and Hubei Provinces. METHODS: Cross sectional seroepidemiologic survey was conducted through IFAT in Anopheles sinensis area and A. anthropophagus plus A. sinensis area respectively in 2006 and 2007. The blood-filter papers collected from residents were tested by IFAT to calculate malaria antibody positive rate (APR) and positive GMRT in different age groups. The predictive infection probability was evaluated by reversible catalytic model based on antibody positive rate in the group of less than 20 year-old and compared to the annual parasite incidence. RESULTS: In 2006 and 2007, the average antibody positive rate in the investigated villages was 6.1% and 12.0% respectively. In An. sinensis areas, the APR in 2007 (12.0%) was significantly higher than that in 2006 (4.1%) (chi2 = 69.9, P < 0.01) while in An. anthropophagus plus An. sinensis areas there was no significant difference in 2006 (10.3%) and 2007 (12.1%) (chi2 = 0.17, P > 0.05). The average positive GMRT of the 12 villages was 26.2 in 2007, slightly higher than that in 2006. In both An. sinensis area and An. anthropophagus plus An. sinensis area, the predictive infection probabilities were higher than the annual parasite incidence with an average 117.3 and 17.20 times higher than the latter respectively. 87.8% of the antibody positive cases were asymptomatic, indicating that there were potential infection sources with symptomatic parasitaemia in the areas. CONCLUSION: Malaria is still prevalent in areas along Yellow River and Huihe River and the actual number of malaria cases are underestimated by the case report system. Malaria reemergence may occur in An. sinensis area but relatively stable in An. anthropophagus plus An. sinensis area.

[Impact of blastocystis hominis infection on ultrastructure of intestinal mucosa in mice].

OBJECTIVE: To observe the ultrastructural change ot intestinal mucosa in mice infected with Blastocystis hominis, and to study the pathogenic mechanism of B. hominis infection. METHODS: 20 Kunming mice were randomly divided into 4 groups: group A treated with immunosuppressant (dexamethasone), group B without immunosuppressant, group C as normal control and group D as immunosuppressant control. Groups A and B were then orally infected with 20(4) cysts of B. hominis. Groups C and D were treated as control by infusing same volume of Locke's solution. Six days after inoculation, mice in each group were killed and mucosa of ileocecum was observed by transmission electron microscope (TEM) and scanning electron microscope (SEM). RESULTS: Under SEM, B. hominis located in enteric cavity and on the surface of ileocecum mucosa. Individual parasites also invaded into mucosa and its fold. Partial destruction of microvilli on the mucosa was observed. TEM observation indicated a reduction of microvilli on the surface of absorptive cells. Mitochondrial edema, rough endoplasmic reticulum dilatation and degranulation were found on absorptive cells and goblet cells. Lymphocyte infiltration and eosinophilia were found in intercellular stroma. Pathological changes in group A were more serious than that of group B. No abnormal change on the mucosal ultrastructure was found in groups C and D. CONCLUSIONS: B. hominis infection causes significant ultrastructural lesion on the ileocecal mucosa in mice. Immune status of the mice can affect the degree of the lesion due to infection.

Malaria control in Henan Province, People's Republic of China.

We analyzed malaria prevalence and evaluated the effect of malaria control measures in Henan Province, People's Republic of China between 1993 and 2004. Data relating to malaria epidemics, malaria control measures and their effects, and vector surveillance between 1993 and 2004 were collected and analyzed. Mean malaria incidence during this period was 2.96/100,000. After integrated vector control measures and appropriate treatment of malaria cases were carried out, the number of malaria cases in Henan Province decreased from 4,815 in 2000 to 2,112 in 2004. The parasite-positive rate and the density of Anopheles anthropophagus were also reduced. Malaria control measures were effective and malaria incidence decreased in Henan. However, there are still more cases in this province than in 1992. Local malaria outbreaks and epidemics have occurred in areas where Anopheles anthropophagus and An. sinensis are present. Thus, malaria control measures should be strengthened.

[Study on number and mature rate of eggs in gravid proglottids of Taenia solium].

OBJECTIVE: To investigate the number and mature rate of eggs in gravid proglottids of Taenia solium. METHODS: Ten worms of Taenia solium, expelled from patients, were detected. Eggs were collected from the last 10 gravid proglottids of each worm. RESULTS & CONCLUSION: The egg number in each mature proglottids varied from 3,900 to 126,520, and the mean number was 28,332. The mature rate of eggs was from 7.00% to 36.00% with an average of 29.12%, which was lower than that in proglottids naturally excreted with feces. With suitable temperature and humidity, the proglottids developed continually after excreted out of host body. Two to three days later, the mature rate of their eggs increased to 85%-90%.