ISSN 1003-8280 CN 10-1522/R 中国疾病预防控制中心 主办
Objective To explore the effective strategies for strengthening malaria control and prevention for ethnic minorities in the remote and poor mountainous areas. Methods Community mobilization, biomedical and behavioral intervention for malaria control were undertaken to promote the local residents economical, geographical, informational and cultural accessibility. Results The residents’knowledge on malaria transmission and prevention, symptoms and medical consultation got increased significantly. Compared with the parameters before the intervention，the odds ratios(OR)of people sleeping in insecticide- treated mosquito nets(ITNs)the night before the final evaluation survey, febrile patients seeking medical attention within 24 hours of onset, and utilizing the public health services for treatment were 37.85%(95％CI: 27.69%-51.88%), 22.28%(6.06%-96.87%) and 7.94%(1.78%-49.54%)respectively. The OR of the annual incidence, the smear positive rate of febrile patients and the indirect fluorescence antibody positive rate of people with a history of fever in the past year were 0.16%(0.08%-0.32%), 0.20% (0.10%-0.39%)and 0.34%(0.22%-0.51%)respectively. Conclusion Community mobilization in combination with biomedical and behavioral interventions for the control and prevention of malaria can effectively lower the incidence and prevalence of malaria in the local area.
Objective To provide evidence for cat flea Ctenocephalides felis felis distribution, overwintering pattern analysis, and further to provide evidence for cat flea and cat flea borne diseases prevention and control, comparison studies of supercooling point (SCP) of adlits, and larvae of cat flea laboratory population were carried out. Methods Thermocouple and digital thermometer were used to determine SCP and freezing point (Ep) of the male and female adults and the later third instar larvae of cat flea laboratory population, and then we analyze the cold tolerance ability of cat flea at the different developmental stages and different gender. Results It was showed that the average temperature of the SCPs of female and male adults were (-18.24±0.26)℃ and (-18.45±0.26)℃ respectively in the starvation conditions, with no significant difference between them found. The average temperature of the EPs were (-15.46±0.30)℃ and (-15.19±0.31)℃ in female and male adults, respectively, there was also no significant difference; while the average temperarure of the SCP in the later third instar larvae was (-8.73±0.40)℃, Ep temperature was (-6.63±0.37)℃, both of them were significantly higher than the supercooling points and freezing points of the male and female adults. Conclusion Statitistically there is no difference in the cold tolerance between male and female adult cat fleas. Larvae is less able to tolerant cold temperature than the adults do, and therefore in northern China, it’s more likely for adults overwintering.
Objective To determine the current resistance of adult Culex pipiens pallens to commonly used pesticides in Jiangsu province, providing the evidence for better mosquito control. Methods The exposure tube method recommended by WHO was applied to measure the median lethal concentration (LC50) for adult mosquitoes. Results The LC50 for field-collected adult mosquitoes in Nanjing, Xuzhou, Lianyungang, Wuxi, Nantong and Huai’an were 0.0173%, 0.0756%, 0.0487%, 0.0070%, 0.0055% and 0.0150% to deltamethrin respectively, and 0.2128%, 0.2711%, 0.1130%, 0.1579%, 0.0504% and 0.0734% to permethrin, respectively. The LC50 to betacypermethrin for field populations in Nanjing, Xuzhou, Lianyungang, Wuxi, Nantong, Huai’an and Suzhou were 0.0224%, 0.0420%, 0.0843%, 0.0023%, 0.0114%, 0.0180% and 0.0108% respectively. The LC50 for Nanjing population to dichlorovos and propoxur were 0.0119% and 0.0129%, while the values for Nantong population to dichlorovos and propoxur were 0.0046% and 0.0077%, respectively. All of tested mosquitoes were intermediately to highly resistant to deltamethrin, with resistance coefficients greater than 100 times in Xuzhou and Lianyungang; lowly to highly resistant to betacypermethrin, with the resistance coefficient up to 94.7 times in Lianyungang in contrast to 2.6 times in Wuxi; and lowly to intermediately resistant to permethrin, with resistance ratios ranging from 11 to 15 times in Nanjing and Xuzhou, and 2.8 times in Nantong. Nanjing population were lowly resistant to propoxur (2.8 times) and sensitive to dichlorovos, while Nantong strains were susceptible to both propoxur and dichlorovos. Conclusion For adult mosquito control in Jiangsu province, the application of deltamethrin and betacypermethrin should be reduced along with increased administration of carbamates, such as propoxur, and organophosphorus pesticides such as dichlorovos. The findings here address consideration and integrated planning to chemical adult mosquito control for delaying or reducing the occurrence and development of pesticid resistance.
Objective To identify the resistance of the great long-tailed hamster (Tscherskia triton) to the 1st generation anticoagulant rodenticide, warfarin, in Xixian, Shanxi province. Methods Non-selective feeding test was conducted. The rodents were given baits containing 0.05% warfarin for 6 consecutive days. Results The mortality of 25 T. triton was 84.0% after exposure, and the average amount of bait intake was 149.20 mg/kg. The average lethal time was 5.29 d. The average intake among survivals was 167.13 mg/kg, and the resistance rate was 16.0%. Conclusion T. triton individuals resistant to the 1st generation anticoagulant rodenticides existed, though resistant population has not yet developed according to the relevant criteria.
Objective To observe the deratization effects of acute and chronic bait poisons applied in bait boxes on rodent, particularly Mus musculus and Rattus norvegicus. Methods On-the-spot test was carried out in West Caishi Village, Licheng district, Jinan city. One bait box, containing 0.5% gophacide and 0.05% sodium diphacinone wheat granules of 50 g in the acute poisoning group or 100 g in the chronic group, was placed in each room. Each group included 90 households for effect assessment using the S100 grill powder-track method. Results For the acute poisoning group, at day 5, 10, 15 and 20, the overall deratization rates were 77.54%, 82.36%, 88.50% and 93.78%, respectively; the killing rates on M. musculus were 76.81%, 82.83%, 88.92% and 94.14%, respectively, and on R. norvegicus 100%, 68.29%, 75.61% and 80.49%, respectively. As to the chronic bait group, at day 10, 20, 30 and 60, the overall deratization rates were 90.93%, 93.17%, 98.11% and 98.28% respectively; the killing rates on M. musculus were 91.12%, 93.24%, 98.18% and 98.24%, respectively and on R. norvegicus 80.95%, 92.86%, 95.24% and 100%. The overall deratization effect at day 10 in the chronic group was better than that of the acute group (u=11.43, P<0.01). Conclusion Chronic anticoagulant baits applied in bait boxes were significantly effective in rodent control.
Objective To study the number of species, endemic species and faunal characteristics of Calyptratae in Pangquangou Nature Reserve of Shanxi province. Methods Entomological classification was used in the study. Results A total of 142 species, 64 genera and 6 families of Calyptratae were found in the nature reserve. Muscidae had the highest proportion at both genus and species levels, accounting for 32.81% of the known genera and 49.30% of known species in the region. Thirty-four cosmopolitan species distributing in 3 or more biogeographic realms were recorded, accounting for 23.94% of the known species in the area, as well as 5 cosmopolitan species which distributed in 6 biogeographic realms, accounting for 3.52%. Four endemic species were found, which accounted for 2.82% of the known species in the area. Conclusion The Calyptratae fauna in Pangquangou Nature Reserve of Shanxi province was mostly palaearctic.
Objective To describe the symptoms of Lucilia sericata infected with Pandora dipterigena and the morphology of P. dipterigena, providing the basis for blowfly control. Methods The morphology of P. dipterigena was observed using aceto-orcein and cotton blue staining. The diameter of conidia, nuclei and conidiophores were measured and photographed. Results The typical adults of L. sericata infected with P. dipterigena usually attached to the stems of Ficus virens, wings spread laterally, with a dense and gray conidiophore layer covering the whole body. Around the body was intensively protruding pseudocystidia of different lengths. The primary conidia was bitunicate with a single nucleus, varying in form from elongated ellipse to subfusiform, (24.8±1.8)μm×(10.8±0.9)μm [(22.1-28.6 μm)×(9.1-14.3 μm)] in diameter with L/D of 2.3±0.2(1.89-2.86). The secondary conidia was similar to the primaries in the appearance, (17.3±1.4)μm×(11.5±1.0)μm [(15.6-19.5 μm)×(9.1-13.0 μm)], L/D=1.5±0.1(1.3-1.7). The pseudocystidia was abundant and monomitic, with a basal diameter of (19.7±1.3)μm (16.2-22.9 μm) and (5.4±1.2)μm (4.0-6.1 μm) to the ends. The rhizoids were monomitic with the diameter of (19.5±0.9)μm (16.6-21.4 μm), with a disc-like holdfast. No resting spores were observed. Conclusion The fungus P. dipterigena may be used in the control of L. sericata.
Objective Propoxur-susceptible Musca domestica strains were established through reverse selective breeding in the laboratory setting. The discriminating concentration of insensitive acetylcholinesterase (AChE) was established according to the AChE sensitivity of the strains. The insensitive gene AChE phenotypes of outdoor M. domestica populations were investigated to provide the basis for delaying pesticide resistance development in M. domestica. Methods The susceptible strains were bred through elimination selection. The insensitive AChE phenotypes in the natural population were investigated by biochemical approaches. Results After 6 cycles of elimination, the sensitivity of the original susceptible strain of M. domestica to propoxur had a 13.87 fold increase. The investigation result showed that more than 40% of the natural population in Beijing had insensitive AChE. Conclusion Carrying insensitive AChE, the susceptible strain of M. domestica should be subject to further reverse selective breeding. The natural population was resistant to propoxur. Hence, the application of this pesticide should be stopped and replaced with an alternative to avoid or delay the development of pesticide resistance.
Objective To identify the distribution patterns and seasonal variation of mosquitoes in rural areas of Guiyang city, providing the basis for the control and prevention of mosquitoes and Japanese encephalitis(JE). Methods Mosquito suction tubes were used in residential areas, pigpens and cattle sheds, while human-baited net traps were used outdoors to capture mosquitoes from August to September in routine survey spots and from April to November in monitoring spots. Every 3 months, these traps were set up to collect mosquitoes for 15 min at the same location. Results Three genera and 7 species of mosquitoes were collected at suburb survey spots of Guiyang city. The composition of Culex tritaeniorhynchus and Armigeres subalbatus accounted for 54.84％ and 33.13％, respectively. From April to November, 10 863 female mosquitoes were collected at monitoring spots, of which Ar. subalbatus accounted for 74.46%, Anopheles sinensis 20.90%, Cx. tritaeniorhynchus 3.00%, and Cx. pipiens quinguefasciatus 1.27%. The density of mosquitoes varied with different habitats, and the highest reached 221.33 mosquitoes/labor-hour in cattle sheds. Mosquito activities began late April, with gradual increase of density in May and peaked in late June and early July. Maintaining high levels from August to September, the density dropped rapidly since October. Seasonal variation was significant among different mosquito species. Conclusion Cx. tritaeniorhynchus was the dominant species with peaking density from August to September, which coincided with the epidemic of JE. Hence, Cx. tritaeniorhynchus may be the main vector of this disease in the region, while other species may be contributive to the viral transmission.
Objective Twenty-two plant extracts were screened for satisfyingly effective repelling agents against ant (Formica fusca), providing the basis for developing efficient, nontoxic and green ant repellents. Methods Using 95% alcohol and water as solvents, the ultrasonic extracts were evaluated in terms of the repellents activities, which were represented by their repellent rates against ants. The t test was performed using SPSS to compare the differences in the repellency rate. Results Satisfactory repelling effects were observed in such alcoholic extracts as Syringa oblate, Zanthoxylum schinifolium, Fructus, Schisandra chinensis and Cinnamomum cassia, with the average repellent rates of 86.9%, 83.9%, 81.3% and 91.2% respectively, followed by Acorus tatarinowii, Herba menthae heplocalycis, Santalum album, Kochia scparia, Illicium verum and Allium sativum, with the average repellency rates ranging from 60% to 80%. By contrast, the average repellent rate of water extracts was under 80%, of which the outstanding representatives were Fructus, S. chinensis and C. cassia with the average repellent rates of 60.9% and 76.2% respectively, followed by I. verum hook. f, Datura stramonium Linn and A. sativum L. with the rates between 50% and 60%. The t test Results showed that water and alcoholic extracts had significantly different repelling effects. Conclusion The repelling effects of 95% alcoholic botanical extracts were significantly better than the water extracts against ants. No matter the solvent was water or alcohol, C. cassia was the best repellent among the 22 botanical extracts.
Objective To understand the infestation situation of major vectors in public places in Henan for the provision of a scientific basis on which the measures for the control and prevention of the vectors in public places in the area were developed. Methods Survey of the infestation situation of major vectors in the area was implemented in four types of public places including hotels, restaurants, schools and medical facilities. Both Powder-spot method and rodent trace method were used for the surveillance of rodent, with sticky-paste method for cockroach, eyeballing method for flies, labor hour method for adult mosquito and container index method for mosquito larvae and pupae. Results With the powder-spot method and rodent trace method, the positive rate of rodent were 5.23% and 4.02% respectively. The positive rate per room for cockroaches was 11.97%, with an average of 8.81 cockroaches per room in the positive rooms, being highest in the restaurants. The positive rate room for flies was 22.38% with an average of 2.43 flies per room in the positive rooms, being highest in the restaurants. The adult mosquito density was 6.49/(man·hour)with Culex pipiens pallens being the dominant species. The positive rate of mosquito larva and pupae was 19.06%. Conclusion It is seen that only the average number of flies in the positive room meets the standards and all the other major indexes were beyond the acceptable limits, indicating that the infestation situation of important vectors in public palaces in Henan was serious, and great importance should be attached to the control and prevention of vectors in public palaces in Henan.
Objective To investigate and identify the species composition and distribution of fleas in the plague focus in Longlin county, providing the basis for plague prevention and control. Methods Fleas were collected from rodents captured by cage traps to calculate the flea-carrying rate and flea index. Free fleas on indoor floors were collected using sticky papers for computation of the floor flea index. Results A total of 2839 fleas in 6 species under 5 genera, 3 families were captured. Xenopsylla cheopis was the dominant species. The average rodent carrying rate, flea index, index of X. cheopis and free flea index on floors were 27.12%, 0.98, 0.78 and 0.046, respectively. Besides, the monthly dynamics of the rodent flea-carrying index and free flea index were bimodal, despite regular pattern on a yearly basis. Conclusion X. cheopis, Pulex irritans and Monopsyllus anisus are the targeted subjects for plague control in Longlin county.
Objective To monitor the dynamics of 10 pathogens carried by the local cockroaches and the cockroaches imported through Shanghai Port. Methods The target pathogens were isolated and cultured, and subject to biochemical identification and the PCR test. Results Pathogens detected from the sample cockroaches included mold, Escherichia coli, Pseudomonas aeruginosa and hepatitis B virus, while Salmonella, Vibrio parahaemolyticus, Vibrio cholerae, Staphylococcus aureus, Mycobacterium tuberculosis and Shigella were not detected. There was no significant difference in the carrying rate among the 4 species of cockroach (χ2=6.20, P>0.05). Conclusion Cockroaches are the intermediate host of pathogens. Therefore, advanced techniques should be used at ports to detect pathogens carried by them.
Objective To identify the host animals of hemorrhagic fever with renal syndrome (HFRS) and their natural infections with hantavirus in Guangxi. Methods Night traps were used to capture rodents indoor and outdoor. After the rats were taxonomically identified, their sera samples and lung tissues were aseptically collected and tested for serum Hantavirus antibody and antigen in lung tissues traps using ELISA. Antigen-positive tissue samples were subject to RT-PCR to identify the viral nuclear acids and typing. Results From 2006 to 2008, 1984 host animals of 17 species were captured, dominated by small rodents. The overall positive rate of Hantavirus antibody among the host animals was 14.51%. Six positive lung tissues were detected from Rattus novegicus, which was confirmed as Seoulvirus (SEOV) through RT-PCR and sequencing. Conclusion The natural foci of HFRS were extensively present in Guangxi with R. novegicus being the major host animal. SEOV was prevalent in the region.
Objective To identify the risk factors of scrub typhus and provide the basis for prevention and control of this disease. Methods A case-control study was conducted to identify the risk factors of the scrub typhus epidemic in the city. All clinically diagnosed cases and confirmed cases were included as the case group. For each patient, two controls were randomly selected from the symptom-free villagers with the same sex and an age gap of smaller than 5 years in the same village. The data were inputted into EpiData 3.1 and analyzed using conditional logistic regression model in SPSS 17.0. Results A total of 78 scrub typhus cases were found, including 16 laboratory-confirmed cases, 34 clinically diagnosed cases and 28 suspected cases. The 1∶M multiple conditional logistic regression analysis showed that sowing and harvest was the risk factor of this epidemic (OR＝6.33, 95%CI:1.12-37.25). Further analysis showed that 51.6% patients and 22.8% of the control subjects had took part in the harvest of soybeans, a risk factor of scrub typhus (OR＝3.62, 95%CI:1.36-9.59). However, the relationship between this epidemic and corn harvest and wheat sowing was not evident (P>0.05). Conclusion The event was an epidemic of scrub typhus among farmers due to bites of mite larvae during unprotected harvest of soybeans.
Objective To identify the status quo of Lyme infections among the population, vector ticks and host animal rats in the forest region of Changbai and Tonghua counties, Jinlin province. Methods Serological samples were collected in the forest area in Changbai and Tonghua. Ticks and rats were captured at random sites. Indirect immunofluorescence assay (IFA) was used for serological detection and nested-PCR for etiological detection of tick and rodent samples as well as gene sequencing typing. Pathogenic isolation and culture was done using BSK culture media. Results The seroprevalence of Borrelia burgdorferi IgG was 12.04% (36/299) in human in Changbai and 9.35% (23/246) in Tonghua. The carrying rate in ticks was 27.08% and 20.41% in Changbai (39/144) and Tonghua (20/98), respectively, while the carrying rate in rodents was 10.00% in both counties (4/40, 1/10). The sequence homology analysis showed that the ticks and rats were carrying the genotype Borrelia garinii. Conclusion Lyme infection was serologically evident in human in Changbai and Tonghua’s forest areas. Etiological Results showed that Ixodes persulcatus and Apodemus agrarius were the key vector and host of Lyme disease in this region.
Objective To analyze the dengue fever epidemic situation in Yunnan province from 2004 to 2008 to provide the basis for developing prevention and control measures. Methods Statistical data from the network direct report system and information of individual case reporting cards and field investigation on dengue fever from 2004 to 2008 were collected and descriptively analyzed using Excel 2007 and ArcView GIS 3.3. Results A total of 116 cases of dengue fever were reported in Yunnan province from 2004 to 2008. Case reports were seen in every month except February and mainly concentrated in from August to November, which peaked in September and October. Among them, 104 cases were imported from Southeast Asian countries including mainly Myanmar and Laos; and 12 cases were local infections. Reports of patients seeking medical treatment came from 10 first-line border counties, and 4 non-border counties (including cities and districts). A certain number of patients were from the province, outside the province or a foreign country. Male patients were more than female ones. The disease affected every age group under the age of 70, while the major victims were at the ages of 0-9, 15-29, 35-39 and 50-54, accounting for 72.41% (84/116). Occupational distribution showed a concentration of cases in business service providers, farmers, students, laborers, scattered children, cadres and migrant workers. Conclusion Most dengue fever patients in Yunnan were imported cases or local cases induced by imported ones. The China-Myanmar and China-Laos border regions are the focal area for dengue prevention and control. The male group, business service providers, farmers, students, workers and scattered children are the high-risk group of infection, and shall be given importance in the prevention and control.
A species of Culicoides and a male Culicoides ruiliensis were newly found during the identification of specimens of the genus Culicoide collected from Tibet and Yunnan: the new species, Culicoides yigongensis sp.nov., and new male C. ruiliensis. The new species is somewhat allied to Cuicoides chengduensis Zhuo et Lee, 1984 and Culicoides liubaensis Liu et Wu, 2005 in the wing spots, but they are distinctly different in the shapes of aedeagus and parameres of male genitalia. The type specimens are deposited in the Shenyang Command Center for Disease Control and Prevention.
1. C. yigongensis sp. nov., (Fig. 1)
The new species is somewhat allied to C. chengduensis Zhuo et Lee, 1984 and C. liubaensis Liu et Wu 2005 in the wing spots, but they are distinctly different in the shapes of aedeagus and parameres of male genitalia.
Male: Wing length 0.95 mm. Eyes without interfacetal hairs； third segment of palpus with sensory pit, palpal ratio(PR)1.80. Wing with 12 pale spots. Ninth stermun with wide and shallow concave， vetral membrane with a few microscopic spicules; back-margin of ninth tergites with apicolateral process, and mid-part with “V” concave; distal portion of aedeagus with a triangular corona, arch height of aedeagus to about 1/3 of total length; parameres separate.
Female: Unknown.
Holotype ♂, Collected on 1991-09-06, from yigong, Bomi county Tibet, China.
2. C. ruiliensis Lee, 1980 (Fig. 2)
Male: Wing lenght 0.90 mm. Eyes with interfacetal hairs； sensilla coeloconica of antenna on 3. 13-15 segments， antennal ratio (AR) 1.04; third segment of palpus with sensory pit, palpal ratio (PR) 2.00. Wing with 9 pale spots. Ninth sternum with wide and deep concave， ventral membrane with a few microscopic spicules; back-margin of ninth tergites with wide “V” concave;aedeagus with mid-part wide, and distal portion columnar, arch height of aedeagus to about 1/3 of total length； parameres separate.
Specimens: 3♂, 2♂ collected on 1985-10-05, from Malipo county, and 1♂ collectedon 1995-09-23, from mengla county Yunnan province, China
Objective To determine the alteration in the prothrombin time(PT) of Rattus tanezumi from warfarin and its killing effect against the pest in Huaian district. Methods The killing effect of warfarin against R. tanezumi was tested by the food intaking method, with PT done with the special instrument. Results There were 15 R. tanezumi that all died during the observation with an average of 10.13 d for its complete death. The average amount of warfarin consumed (original material) was 2.57 mg/kg, and the average PT (INR) was 1.41, with no statistical significance between the female and male mice found (t=0.159, P=0.876). Conclusion Warfarin could kill R. tanezumi effectively in Huaian district, with the PT value ranging from 0.94 to 2.88.
Objective To find out the appropriate measures for the control and prevention of rodent pests in the rural areas of Heilongjiang province. Methods Anticoagulants (bromadiolone) and the poison bait station were used in the rural areas in Rattus norvegicus and Mus musculus when sewer rats concentrated, with villages as the basic test sites to which the poison bait station for long periods of time. Results The amount of the bait consumed during the test period that lasted for one and half years decreased by 95.65%. Four months later, it was found that the snap-trap rate decreased by 83.67%. The highest rebound height of the bait consumption in the second year was about 23% of the maximum consumption at the same time in the preceding year.Conclusion The measure provides a solution to the rodent pest control in the villages with a simple and easy technique, which can both meet the end of sustainable control of rodent pests in the villages and ensure safety for people, livestock and birds.
Objective To identify the species composition, distribution, seasonal variation and infestation of cockroaches in the urban areas of Dongyang city, providing the basis for development of roach control strategies. Methods Roach glue traps were used to monitor the dynamics of cockroaches. Results Three species of cockroaches under 2 genera of 2 families were found in the region, and Blattella germanica was the dominant species. From January 2007 to December 2008, 3000 pieces of glue traps were administered with a result of 977 captures. With 391 traps positive of captives, the infestation rate ranged from 0 to 31.2%, which was significantly different among various industries (χ2＝213.61, P<0.01). Peaking from June to November, the roach density manifested a unimodal pattern on seasonal dynamics. Scaling highest from July to September, the infestation rates were statistically different through the months (χ2＝153.01, P<0.01). Conclusion Farmer’s markets, hospitals and the catering industry constituted the major breeding places for cockroaches in Dongyang city’s urban areas. In view of the constant expansion and gradual invasion of cockroach infestation to hospitals and residential areas, effective control measures should be taken to curb the spread.
Objective To understand the distribution, composition ratio, the population density and seasonal variation of flies and the pathogens they could carry in the different major coastal ports in Fujian province. Methods The species, composition ratio and population density and seasonal variation of flies were investigated in the different frontier ports, such as Ningde, Fuzhou Airport, Mawei, Putian, Quanzhou and Xiamen from 2006 to 2009 years. The density(number/cage·day) was calculated by baiting cage. Statistical analysis with the software SPSS 11.51 was made to evaluate the density index and seasonal fluctuation of flies in different places. And the Aerobic plate count and Coliforms in the major flies were tested. Results A total of 190 034 flies, classified into 65 species (13 in Ningde, 40 in Fuzhou airport, 37 in Mawei, 32 in Putian, 18 in Quanzhou and 21 in Xiamen) that belong to 34 genera, 5 families, were captured from 2006 to 2009. Among them, Chrysomya megacephala (42.92% ), Musca domestica (14.93%) and Lucilia sericata (10.91%) were the dominant species. The density index was highest in rubbish heap(149.42/cage·day), followed by Sewage treatment plants (139.67/cage·day) and the palaces outside of food factories (132.18 /cage·day), with freight depot/storehouse (13.08/cage·day) being the lowest in the density. The peak density in Xiamen, the Airport and Mawei was about two months later than that in Putian, Quanzhou and Ningde. Except Ningde and Fuzhou airport, a bimodal density distribution with seasonal variation was seen in the four ports. A large number of total bacteria and coliform bacteria were detected in flies in some ports. Conclusion There are more fly species in Fuzhou Airport, Mawei and Putian. The density of flies in six coastal ports is much higher than that specified in the National Control Standard. The dominant fly species in all the coastal ports are similar. The Results of fly pathogen examination and the higher fly density reveal that there is a high potential risk of intestinal infectious diseases. Environmental remediation is the basic measure for the control of flies．
Objective To gain an insight into the mosquito species, their density and their growth and decline with different monitoring methods. To understand their distribution patterns, and the dominat mosquito species obtained with different monitoring methods, in order to provide relatively accurate early warning information for the proper implementation of mosquito density monitoring and effective control and prevention of Japanese encephalitis(JE) and other vector-born diseases. Methods The “National Vector Biological Monitoring Program (trial)” issued by the Ministry of Health of P.R. China was used as a guideline for the investigation and monitoring. Results The Results of mosquito larvae density monitoring showed that the positive rate of the idle containers was highest from July to September every year. Of the idle containers the container index (CI) was 36.83%, the housing index (HI) was 34.86% and breteau index (BI) was 24.14. The light trap method, human induced method and mosquito and oviposition trap method were employed to investigate the prevalence of mosquitoes in Baoji city and some of its urban counties from 2006 to 2009. The findings showed that the mosquitoe species acquired were closely related to the ecological environment where they bred and the monitoring Methods used. The types of mosquitoes acquired with different monitoring Methods and in different ecological environments were different. The largest number and types of mosquitoes was obtained with the light trap method, with Culex pipiens pallens (58.82%) being the dominant species, and the mosquitoes obtained by human induced method were mainly Aedes albopictus (77.09%). Those acquired with the capture method were dominantly Cx. tritaeniorhynchus and Armigeres subalbatus, which accounted for 60.94% and 22.21% respectively. The mosquito Cx. pipiens pallens was dominant in urban, and rural residential areas and farming and aquaculture areas accounting for 90.00%, 40.45% and 70.05% respectively, with the mosquito Ae. albopictus being the major species (36.80%) in special places. In terms of the time distribution, it was in August that the mosquito density reached its peak in Baoji. Conclusion It is seen that the types of mosquitoes acquired with different monitoring Methods are different, indicating that it is advisable that proper choice of the monitoring Methods is exercised to avoid bias in routine monitoring. It is desirable that the anti-mosquito measures be taken in April and May befor the peak mosquito densities, in order to reduce the occurrence of mosquito-borne diseases in Baoji.
Objective To learn the species of biological vector and its pattern of variation with seasons in Ankang city for providing data for the control and prevention of the vector-born diseases. Methods The surveillance sites were set up in the light of “ The National Plan for the Survei11ance of Biological Vector”, where the species and densities of vectors like mosquitoes, f1ies, mice and cockroach were investigated by way of manual mosquito-catching trap, cage-trapping, paste-trapping and rat trapping, respective1y. Results It was found that there were 6 species and 4 genuses of mosquitoes in Ankang city, of which Armigeres subalbatus was the dominant，accounting for 41.06％, followed by Anopheles sinensis (19.69％) and Culex tritaeniorhynchus (17.48％). The density of mosquitoes reached its peak in late August. There were 2 families of flies, including 8 species and 8 genuses, in the district, of which Musca sorbens was the dominant specie, accounting for 48.68％, followed by M. domestica and Lucilia sericata and Chrysomya megacephala, which accounted for 26.78%, 9.55%, 4.84% respectively, with the density of flies highest of the year in July. Two families of the cockroaches, including 2 species and 2 genuses were found in the region, with Periplaneta americana (51.42％) being the dominant species, followed by Blattella germanica (48.58％)，and their density peak in the region was reached in November. The rat-shape animals belonging to 3 species and 3 genuses of 1 fami1y were identified in the area, with the dominant species being Rattus norvegicus (90.34%), followed by Mus musculus (6.90%), and their peak density was seen in September and October of the year. Conclusion It was found that there was a high density of the biological vector in the Ankang city. It is suggested that the government take comprehensive measures for its control and prevention to reduce the density of the biological vector to a level that meets the control standards of national health cities, realizing an effective control and prevention of the outbreak and prevalence of the vector-born diseases.
Objective To understand the trend of rodents in the hydraulic cascade development process in the Yichang section of the Three Gorges area, in order to provide important background information for medical assessment of the environment where large-scale water control projects were planned, and take measures timely to deal with problems associated with the pests. Methods Sequential investigation into the density and population of rodents in the Yichang section of the Three Gorges area had been implemented with the trap-night method since 1959. Results The density of rodents in the section in different periods of time generally presented a declining trend with a higher density outdoors than indoors. Compared with other periods the density of rodents from 1971 to 1980 was of the highest value (12.98%). In the years from 2001 to 2009, when the second and third stage construction of the Three Gorges Project was completed, the density of rodents in the section fell to its lowerest level (1.16%) in the history, which should be credited to the four times of thorough bottom clearance and the active rodent eradication in the reservoir area. The significant difference in both outdoor and indoor rodent species composition may be related to the alteration of the ecological environment, the migration and proliferation of biological species, and the competition between the different species. Conclusion The thorough sanitary clearances have a positive effect on the reduction of the rodent density in the reservoir area,which now is at the minimum level. It is not seen that the hydropower projects have a significant impact on it.
Objective To determine the population density and dynamics of vectors in Baoshan district of Shanghai, providing the basis for epidemiological analysis of vector-borne diseases as well as vector control. Methods The rat density was monitored by night traps (using peanuts as baits), mosquito density by the labor hour method, fly density by cage traps and cockroach density by glue traps. Results From 2006 to 2008, 25 898 times of rat trap deployment was performed, resulting in 24 237 positive catches and 77 captured rats; the rodent density was 0.32%. With 5345 mosquitoes captured, the mosquito density was 9.28/labor-hour. The 540 fly-alluring cages had trapped 932 flies, and the fly density was 1.73/cage. A total of 6480 roach glue traps were placed and recovered, resulting in 448 positive traps and 3316 captives. The cockroach density was 0.51/trap, and the average infestation rate was 6.91%. Blattella germanica was the dominant species. Conclusion The focal targets for prevention and control in Baoshan district of Shanghai included Rattus norvegicus, Mus musculus, Culex pipiens pallens, Lucilia sericata, Musca domestica and B. germanica. To reduce the vector density, environment-centered integrated measures dependent on the breeding places, habitual traits and seasonal variation should be adopted.
Objective To know the density of flies and their seasonal fluctuation in Minhang district for providing a scientific basis for their control. Methods The cage trap method was used, with one canopy with fresh baits set at each monitoring point for six hours (9：00 to 15：00). The flies caught by cage were collected after killed by ether and classified, and the density calculated. Results The average density of flies was 1.09 flies/cage, and that in green belt, farmers market and residential area was 1.44, 1.15 and 0.95 flies/cage, respectively. The dominant species were Musca domestica, Sericata, Sarcophagidae and Chrysomya megacephal. A bimodal density distribution with seasonal variation was seen with the peak mainly in June and September. Conclusion The density and population of flies vary with the season and breeding environment, with temperature, the breeding environment and the control measures being the major influencing factors. Integrated control measures should be taken with a top priority given to the environment management, plus chemical control to reduce the density of flies and control the prevalence of infectious diseases.
Objective To identify the relationship between the outbreak of hemorrhagic fever with renal syndrome (HFRS) and the distribution of animal hosts in Chengde city, and provide the corresponding prevention and control strategies. Methods The host animals of HFRS were monitored using night traps. The epidemic data were analyzed using Excel and Epi Info. Results Since the first HFRS case in 1984, serological verification and monitoring of the host animals had been conducted in the city based on the epidemic dynamics. The captured rodent species included Niviventer confucianus, Apodemus agrarius, A. peninsulae, Myodes rufocanus, Rattus norvegicus, Tscherskia triton, Spermophilus dauricus, and Cricetulus barabensis, in which virus-carrying animals were mainly R. norvegicus, A. agrarius, N. confucianus, and A. peninsulae. A. peninsulae was a virus-carrying species first captured in Pingquan county in the fall of 2004, while N. confucianus was first captured in Chengde Summer Resort in 2005. The highest virus-carrying rate appeared in 2002 (8.40%). After 2005, no virus host animals were observed. Conclusion The prevalent HFRS pathogen in Chengdu city was the SEO strain. Strengthening monitoring, immunization and eradication in the city and implementing targeted prevention measures to specific focal populations are crucial to effective prevention and control of the epidemic.
Objective To determine the epidemiological characteristics and risk factors of rabies in Jinan, in order to provide the basis for prevention and control strategies. Methods Epidemiological case study and descriptive statistical analysis were conducted. Results From 2006 to 2008, 17 cases of rabies occurred in Jinan city, and all cases resulted in death. The patients were mostly farmers, accounting for 64.71% (11/17). Except one case without clear exposure clue, all cases were caused by dog bites, accounting for 100% (16/16). 87.50% (14/16) of the dog-bited cases were of grade Ⅲ exposure. After exposure, 31.25% (5/16) patients did not receive treatment at all, and 37.50% (6/16) of them did not receive injection of rabies vaccine, and only 1 patient was administered non-standard rabies vaccine and immune globulin. Conclusion Most rabies patients in Jinan city were rural residents, due to lack of timely, proper wound treatment for the exposed and timely vaccination and passive immunization against rabies, all cases were fatal. Therefore, public health education about the knowledge of rabies prevention and control should be further strengthened.
Objective To determine the species and density of Japanese encephalitis (JE) vectors and JE infections in the animal host in Huangshi city, Hubei province, providing the basis for development of JE prevention and control measures. Methods From April to October, 2008, mosquito species and density were monitored using the labor hour method, and JE antibody levels in pig serum were measured using the PCR in laboratory. Results The predominant mosquito species in Huangshi was Culex tritaeniorhynchus, followed by Cx. pipiens quinquefasciatus and Anopheles sinensis. Cx. tritaeniorhynchus accounted for 51.99% of the total captured mosquitoes with a density of 3.97/labor-hour. The mosquito density peaked in the second half of June, and remained stable from early July to the end of October. The average positive rate of JE antibody in pig serum was 6.2% with a maximum of 7.2%, which demonstrated an upward trend over time. Conclusion In view of the high density of Cx. tritaeniorhynchus, a vector of JE, in Huangshi, Hubei, and the infection rate among the host animal pigs increasing with the mosquito density, there was a natural environment for the spread of JE.
Objective To understand the epidemiological characteristics of Japanese encephalitis(JE) in Baoshan city from 2005 to 2008 in order to provide a scientific basis for the control and prevention of the epidemic. Methods Descriptive epidemiological analysis was performed on the cases of JE reported in the area from 2005 to 2008. Results A total of 224 JE cases were reported in Baoshan city, 2005-2008, with the annual incidence being 1.70/105, 2.68/105, 2.46/105, 2.35/105, respectively in the years in sequence. It was seen that the incidence was highly sporadic in the individual years, with the peak incidence occuring from July to August, accounting for 63.84% of the total incidence. Children under the age of 10 were most frequently affected, constituting 76.79% of the total cases. There were 3 cases who died of the epidemic with a mortality of 1.34%. Conclusion The epidemic of JE was well under control in Baoshan city, but it is still needed to take comprehensive measures based on vaccination and mosquito control and prevention to make it better.
Objective To analyze the epidemiological surveillance data on brucellosis in Chaoyang city from 1999 to 2008, infer the possible prevalent strain from the information and identify the major source of infection, providing the basis for prevention and control of brucellosis. Methods Based on epidemiological surveillance, sporadic cases and outbreaks from 1999 to 2008 among the focal population in the key areas and 7 counties of the city, as well as cattle and sheep, were subject to serological tests. The sera samples of the 3 groups were collected for antibody detection. Spearman analysis was conducted to identify the correlation between the annual incidence in humans and the number of cattle and sheep herds，the annual incidence and the antibody positive rate of cattle and sheep sera samples, and the antibody seroprevalence in the focal population and that in cattle and sheep．Results The annual incidence was noticeably correlated with the number of cattle and sheep herds and the seroprevalence in sheep (r=0.779, P<0.01; r=0.816, P<0.01; r=0.857, P<0.01)．Blood culture of the pathogens collected from 18 patients in 2009 revealed 2 strains of type 3 Brucella melitensis. Conclusion Brucella melitensis was the major cause of brucellosis epidemics in Chaoyang city, indicating that sheep should be specifically monitored in prevention and control of brucellosis.
Objective To determine the epidemiological characteristics, long-term trend and regional typing of hemorrhagic fever with renal syndrome (HFRS) in Huludao city, which would provide the basis for development of specific control strategies. Methods Epidemiological data on HFRS in the city were retrieved from the National Noticeable Infectious Disease Reporting System for the analysis. Indirect immunofluorescence assay (IFA) was performed to identify the Hanta viral antigen in rodent lung samples for the calculation of virus-carrying rates. The hemagglutination inhibition test was adopted to serotype the serum samples collected from patients at the recovery stage. Results Remaining at a high level since 1998, the HFRS incidence sharply declined from 2006. An onset peak in spring was noticeable, while the number of cases from February to June accounted for 61.37% of the overall patients. The young and middle-age male farmers were at a high risk of contracting the disease. The rat density and virus carrying rates were high, and the SEO serotype was identified from the recovering patients’ sera samples. Conclusion Noticeable decrease of the HFRS incidence in Huludao city was attributable to large-scale vaccination. The SEO serotype was prevalent in this region, while transformation into mixed-type was not yet observed. It is essential to intensify the rodent prevention and control measures and strengthen the observation of the long-term effect of vaccination among inoculated populations. Supplementary immunization may be conducted when necessary.
Objective To analyze the overall situation and development trends of professionals in pest control organization (PCO) in China. Methods The staff composition (including practice time, age and education background), training, remuneration and health insurance in this domestic industry were compared with the foreign counterparts. Results Professionals in China’s PCO had short practice time, wide-span age distribution, deficient experience, low educational level, unstable performance, poor remuneration and shortage of corresponding occupational health insurance, indicating significant difference with the same industry in foreign countries. Conclusion PCO professionals are the key to the development of an enterprise, or even the whole industry. Their quality is determinant of the industry’s overall service quality. With the overall improvement of the quality of PCO professionals in China, this industry will achieve rapid development and present a new image.
This paper summarizes the common candidate antigens in transmission blocking vaccines (TBVs) and discusses the status quo of research on antigen vaccines before and after fertilization of gametes, as well as the relevant antigen vaccines in the body of mosquitoes. The hotspots in TBVs such as the study of reactionogenicity of candidate antigens and practical effects of adjuvants and their prospects are also reviewed to provide the basis for further research on malaria transmission blocking vaccines.
Vector monitoring is an important approach for the prevention and control of dengue fever. Scientific methodology plays a leading role in dengue control. This study reviews the advances in multiple monitoring Methods for vectors of dengue fever, compares the strengths and weaknesses, and analyzes the existing problems in the domestic monitoring approaches. Introducing an epidemiological method for monitoring adult mosquitoes according to China’s current conditions, this article looks forward to the development trend of vector monitoring modes in future.
Reticulitermes chinensis Snyder (Isoptera: Rhinotermitidae) is a species of termites with broad distribution that damages the wooden structures of buildings and the xylems of living old trees in Beijing, Tianjin, Xi’an and the drainage area of Yangtse River in China. It has been studied by some Chinese researchers for a long time, thereby resulting in abundant biological and ecological information. This article summarizes the biological, ecological characteristics and control measures of R. chinensis. Further study is needed to explore the effective control strategies against this species.
To further study the structure and nature of the foci of plague in Hebei province, this article summarizes the biological characteristics of Yersinia pestis isolates in the regions by analyzing the large amounts of data collected. By introducing the biochemical characteristics, nutritional needs, plasmid characteristics, virulence factors, virulence and toxins and other aspects, the study has concluded that Y. pestis isolated in Hebei province belongs to Group B of the Ordos Plateau, of which the nutritional needs are characterized by glycine semi-dependence and tryptophan dependence. These strains contain 4 kinds of plasmids, of which 13×106 plasmid is specifically carried by Meriones unguiculatus in the Inner Mongolian. Some strains lack the 45×106 plasmid, though all of isolates were F1 antigen and streptozotocin (PstⅠ)-positive. However, only a certain portion of the strains were positive for pigmentation (Pgm) and VW antigen, indicating genetic instability and moderate toxicity.
Objective To control rat density and ensure public health security at the capital airport. Methods In a routine rodent density investigation carried out by Beijing Capital Airport Entry-Exit Inspection and Quarantine Bureau from October 15 to 17, 2009, it was found that the average rodent density in some areas of the capital airport was up to 5.17%, which exceeded the standard limit of International Hygiene Airport. An emergency response was immediately launched according to the Frontier Public Health Emergency Response Program, including the establishment of an emergency response team, development of the rodent control plan, administration of rodenticides and deployment of glue traps to reduce the rat density. Results After 30 days of emergency treatment, the rodent density decreased to 0.50%, and the monitoring after 40 days revealed zero rat density (based on the night trap measurement). Conclusion The Frontier Public Health Emergency Response Program played a crucial role to proper handling of rodent density increase.
Birds, rodents and other wild animals are specifically and strictly controlled and managed at airports. By analyzing the hazard of rodents to airports, this paper suggests integrated strategies for rodent control in such a setting, including long-term rodent monitoring, development of rodent-unfriendly environments and use of multiple rodenticidal arms. At last, this paper briefly describes several noteworthy problems in rodent control at airports.
The complexity of the urban environment provides a wide range of suitable spaces for the survival and breeding of rodents, leading to serious rodent infestation and difficulties in rodent control in urban areas. The public health and lives are thereby exposed to great potential hazards. By analyzing the particularities of China’s urban environment and the habitual traits of urban rodents, this paper describes the distribution and characteristics of urban rodent infestation, and discusses the difficulties in the rodent control in China’s cities as well as rodenticide resistance. Finally, it puts forward an integrated and targeted strategy for urban rodent control.
