Wuchereria bancrofti, Dirofilaria immitis, and Dirofilaria repens are filarial nematodes transmitted by mosquitoes belonging to Culex, Aedes, and Anopheles genera. Screening by vector dissection is a tiresome technique. We aimed to screen filarial parasites in their vectors by single and multiplex PCR and evaluate the usefulness of multiplex PCR as a rapid xenomonitoring and simultaneous differentiation tool, in area where 3 filarial parasites are coexisting. Female mosquitoes were collected from 7 localities in Assiut Governorate, were microscopically identified and divided into pools according to their species and collection site. Detection of W. bancrofti, D. immitis, and D. repens using single PCR was reached followed by multiplex PCR. Usefulness of multiplex PCR was evaluated by testing mosquito pools to know which genera and species are used by filarial parasites as a vector. An overall estimated rate of infection (ERI) in mosquitoes was 0.6%; the highest was Culex spp. (0.47%). W. bancrofti, D. immitis, and D. repens could be simultaneously and differentially detected in infected vectors by using multiplex PCR. Out of 100 mosquito pools, 8 were positive for W. bancrofti (ERI of 0.33%) and 3 pools each were positive for D. immitis and D. repens (ERI 0.12%). The technique showed 100% sensitivity and 98% specificity. El-Nikhila, El-Matiaa villages, and Sahel Seleem district in Assiut Governorate, Egypt are still endemic foci for filarial parasites. Multiplex PCR offers a reliable procedure for molecular xenomonitoring of filariasis within their respective vectors in endemic areas. Therefore, it is recommended for evaluation of mosquito infection after lymphatic filariasis eradication programs.
Aedes/*parasitology ; Animals ; Anopheles/*parasitology ; Culex/*parasitology ; Dirofilaria immitis/genetics/*isolation & purification ; Dirofilaria repens/genetics/*isolation & purification ; Egypt ; Entomology/methods ; Female ; Multiplex Polymerase Chain Reaction/*methods ; Parasitology/methods ; Sensitivity and Specificity ; Wuchereria bancrofti/genetics/*isolation & purification

Wuchereria bancrofti, Dirofilaria immitis, and Dirofilaria repens are filarial nematodes transmitted by mosquitoes belonging to Culex, Aedes, and Anopheles genera. Screening by vector dissection is a tiresome technique. We aimed to screen filarial parasites in their vectors by single and multiplex PCR and evaluate the usefulness of multiplex PCR as a rapid xenomonitoring and simultaneous differentiation tool, in area where 3 filarial parasites are coexisting. Female mosquitoes were collected from 7 localities in Assiut Governorate, were microscopically identified and divided into pools according to their species and collection site. Detection of W. bancrofti, D. immitis, and D. repens using single PCR was reached followed by multiplex PCR. Usefulness of multiplex PCR was evaluated by testing mosquito pools to know which genera and species are used by filarial parasites as a vector. An overall estimated rate of infection (ERI) in mosquitoes was 0.6%; the highest was Culex spp. (0.47%). W. bancrofti, D. immitis, and D. repens could be simultaneously and differentially detected in infected vectors by using multiplex PCR. Out of 100 mosquito pools, 8 were positive for W. bancrofti (ERI of 0.33%) and 3 pools each were positive for D. immitis and D. repens (ERI 0.12%). The technique showed 100% sensitivity and 98% specificity. El-Nikhila, El-Matiaa villages, and Sahel Seleem district in Assiut Governorate, Egypt are still endemic foci for filarial parasites. Multiplex PCR offers a reliable procedure for molecular xenomonitoring of filariasis within their respective vectors in endemic areas. Therefore, it is recommended for evaluation of mosquito infection after lymphatic filariasis eradication programs.
Aedes/*parasitology ; Animals ; Anopheles/*parasitology ; Culex/*parasitology ; Dirofilaria immitis/genetics/*isolation & purification ; Dirofilaria repens/genetics/*isolation & purification ; Egypt ; Entomology/methods ; Female ; Multiplex Polymerase Chain Reaction/*methods ; Parasitology/methods ; Sensitivity and Specificity ; Wuchereria bancrofti/genetics/*isolation & purification

OBJECTIVETo identify the biological forms, sporozoite rate and molecular characterization of the Anopheles stephensi (An. stephensi) in Hormozgan and Sistan-Baluchistan provinces, the most important malarious areas in Iran.

METHODSWild live An. stephensi samples were collected from different malarious areas in southern Iran. The biological forms were identified based on number of egg-ridges. Molecular characterization of biological forms was verified by analysis of the mitochondrial cytochrome oxidase subunit I and II (mtDNA-COI/COII). The Plasmodium infection was examined in the wild female specimens by species-specific nested-PCR method.

RESULTSResults showed that all three biological forms including mysorensis, intermediate and type are present in the study areas. Molecular investigations revealed no genetic variation between mtDNA COI/COII sequences of the biological forms and no Plasmodium parasites was detected in the collected mosquito samples.

CONCLUSIONSPresence of three biological forms with identical sequences showed that the known biological forms belong to a single taxon and the various vectorial capacities reported for these forms are more likely corresponded to other epidemiological factors than to the morphotype of the populations. Lack of malaria parasite infection in An. stephensi, the most important vector of malaria, may be partly due to the success and achievement of ongoing active malaria control program in the region.

Animals ; Anopheles ; genetics ; parasitology ; DNA, Mitochondrial ; genetics ; DNA, Protozoan ; genetics ; Eggs ; classification ; parasitology ; Female ; Iran ; Male ; Parasite Load ; Plasmodium ; genetics ; isolation & purification ; Polymerase Chain Reaction ; Sporozoites

Vivax malaria is a significant military and civilian health threat in the north of the Republic of Korea (ROK). The island of Baengnyeong-do is the westernmost point of the ROK and is located close to the southwestern coast of the Democratic People's Republic of Korea (DPRK). Mosquitoes were collected using a black light trap on Baengnyeong-do, and Anopheles spp. were assayed by PCR, to identify the species, and screened for sporozoites of Plasmodium vivax. Of a subsample of 257 mosquitoes, Anopheles lesteri was the most frequently collected (49.8%), followed by Anopheles sinensis (22.6%), Anopheles pullus (18.7%), Anopheles kleini (7.8%), and Anopheles belenrae (1.2%). The overall sporozoite rate was 3.1%, with the highest rates observed in An. kleini (15.0%), An. sinensis (5.2%), and An. lesteri (1.6%). No sporozoite positive An. pullus or An. belenrae were observed. The results extend our knowledge of the distribution and potential role in malaria transmission of An. kleini, An. lesteri, and An. sinensis, for an area previously considered to be at a low risk for contracting vivax malaria.
Animals ; Anopheles/*classification/genetics/*parasitology ; Plasmodium vivax/genetics/*isolation & purification ; Polymerase Chain Reaction ; Prevalence ; Republic of Korea

We investigated the seasonality of Anopheles mosquitoes, including its species composition, density, parity, and population densities of mosquitoes infected with the parasite in Ganghwa-do (Island), a vivax malaria endemic area in the Republic of Korea. Mosquitoes were collected periodically with a dry-ice-tent trap and a blacklight trap during the mosquito season (April-October) in 2008. Anopheles sinensis (94.9%) was the most abundant species collected, followed by Anopheles belenrae (3.8%), Anopheles pullus (1.2%), and Anopheles lesteri (0.1%). Hibernating Anopheles mosquitoes were also collected from December 2007 to March 2008. An. pullus (72.1%) was the most frequently collected, followed by An. sinensis (18.4%) and An. belenrae (9.5%). The composition of Anopheles species differed between the mosquito season and hibernation seasons. The parous rate fluctuated from 0% to 92.9%, and the highest rate was recorded on 10 September 2008. Sporozoite infections were detected by PCR in the head and thorax of female Anopheles mosquitoes. The annual sporozoite rate of mosquitoes was 0.11% (2 of 1,845 mosquitoes). The 2 mosquitoes that tested positive for sporozoites were An. sinensis. Malarial infections in anopheline mosquitoes from a population pool were also tried irrespective of the mosquito species. Nine of 2,331 pools of Anopheles mosquitoes were positive. From our study, it can be concluded that An. sinensis, which was the predominant vector species and confirmed as sporozoite-infected, plays an important role in malaria transmission in Ganghwa-do.
Animals ; Anopheles/*classification ; *Disease Vectors ; *Endemic Diseases ; Head/parasitology ; Malaria/*epidemiology/*transmission ; Plasmodium/isolation & purification ; Population Dynamics ; Republic of Korea/epidemiology ; Seasons ; Thorax/parasitology

Changing patterns of the reemerging Plasmodium vivax malaria in the Republic of Korea (South Korea) during the period 1993 to 2005 are briefly analyzed with emphasis on the control measures used and the effects of meteorological and entomological factors. Data were obtained from the Communicable Diseases Monthly Reports published by the Korea Center for Disease Control and Prevention, and webpages of World Health Organization and United Nations. Meteorological data of Kangwon-do (Province) were obtained from local weather stations. After its first reemergence in 1993, the prevalence of malaria increased exponentially, peaking in 2000, and then decreased. In total, 21,419 cases were reported between 1993 and 2005 in South Korea. In North Korea, a total of 916,225 cases were reported between 1999 and 2004. The occurrence of malaria in high risk areas of South Korea was significantly (P<0.05) correlated with the mosquito population but not with temperature and rainfall. Control programs, including early case detection and treatment, mass chemoprophylaxis of soldiers, and international financial aids to North Korea for malaria control have been instituted. The situation of the reemerging vivax malaria in the Republic of Korea is remarkably improving during the recent years, at least in part, due to the control activities undertaken in South and North Korea.
Seasons ; Plasmodium vivax/drug effects ; Military Personnel/statistics & numerical data ; Malaria, Vivax/*epidemiology/parasitology/*prevention & control ; Korea/epidemiology ; Incidence ; Humans ; Disease Outbreaks/*prevention & control ; Communicable Diseases, Emerging/*epidemiology/parasitology/*prevention & control ; Chloroquine/administration & dosage ; Antimalarials/administration & dosage ; Anopheles/parasitology ; Animals

Extensive previous studies on taxonomy, behavior/bionomics and control of Anopheles sinensis are reviewed and summarized. Recent molecular identification revealed that the population of An. sinensis complex includes An. sinensis, An. pullus, An. lesteri and at least two new species, and An. yatsushiroensis is synonmy of An. pullus. An. sinensis is the main vector specie of vivax malaria in Korea. Larvae of An. sinensis breed in wide range of habitats which are naturally-made clean water, stagnant or flowing; main habitats include rice fields, ditches, streams, irrigation cannals, marshes, ponds, ground pools, etc. Their host preferences are highly zoophilic. Human blood rate is very low (0.7-1.7%) ; nevertheless An. sinensis readily feeds on man when domestic animals are not found near by. They feed on hosts throughout the night from dusk to dawn with a peak period of 02: 00-04: 00 hours; they are slightly more exophagic (biting outdoors) ; much larger numbers come into the room when light is on. Main resting places are outdoors such as grasses, vegetable fields and rice fields. A mark-release-recapture study resulted that 37.1% was recaptured within 1 km, 29.4% at 1-3 km, 21.1% at 3-6 km, 10.3% at 6-9 km and 2.1% at 9-12 km distance. An. sinensis hibernate outdoors (mostly under part of dense grasses) during October-March. At the end of the hibernation period (March-April) they feed on cows at daytime. Until today any single measure to effectively control An. sinensis population has not been found. Indoor residual spray with a long-lasting insecticide can not reduce vector population densities, but shorten their life spans in some degree, so contributes to malaria control.
Animals ; Animals, Domestic/parasitology ; Anopheles/parasitology/*physiology ; Bites and Stings ; *Ecosystem ; Feeding Behavior ; Humans ; *Insect Vectors ; Korea ; Larva/physiology ; *Malaria, Vivax ; Mosquito Control ; Plasmodium vivax ; Population Density ; Seasons

OBJECTIVETo establish a minimum medical geographic information systems (GIS) database as a spatial decision supporting system (SDSS), and to use the database into public health practice in China.

METHODSSpatial data collected from different sources were standardized as decimal degree format, including: (1) satellite images covering areas of China; (2) digital maps of China in vector files; (3) diseases database and relevant models.

RESULTSNecessary satellite images for the database have been collected from NOAA AVHRR, Landsat TM, etc., including the normalized difference vegetation index (NDVI) images from AVHRR, earth surface temperature images from AVHRR, GTOPO30 DEM images from USGS and landuse images from USGS. The digital vector files for GIS analysis were collected including political (county, provinces, country) boundaries file, environmental (drainage, land cover, soil type) vector file, population data and climate data; Data on diseases mainly generated from survey or case reporting. Relevant models on transmission of Schistosoma japonicum and Plasmodium vivax, and models of Oncomelania hupensis and Anophores sinansis were developed, and the relevant environmental factors related to incidence of cancers were mapped, to test and verify those database.

CONCLUSIONThe database unified the data from different sources for users. Minimum medical data included in the database could be used in the practice of public health. It is expected that this database be used in a wider range.

Animals ; Anopheles ; parasitology ; China ; epidemiology ; Databases, Factual ; Disease Reservoirs ; Disease Vectors ; Ecology ; Geographic Information Systems ; Humans ; Malaria ; epidemiology ; prevention & control ; transmission ; Plasmodium vivax ; Satellite Communications ; Schistosomiasis japonica ; epidemiology ; prevention & control ; transmission ; Snails ; parasitology

To evaluate the factors that determine the transmission level of vivax malaria using vectorial capacity, entomological surveys were conducted from June to August, 2000. From 6 nights of human-bait collection in Paju, the human biting rate (ma) was counted as 87.5 bites/man/night. The parity of Anopheles sinensis from human baiting collections fluctuated from 41% to 71% (average 48.8%) of which the rate gradually increased as time passed on: 35.2% in Jun.; 55.0% in July; 66.2% in Aug. From this proportion of parous, we could estimate the probability of daily survival rate of An. sinensis to be 0.79 assumed with 3 days gonotrophic cycle and the expectancy of infective life through 11 days could be defined as 0.073. Blood meal analysis was performed using ELISA to determine the blood meal source. Only 0.8% of blood meals were from human hosts. We could conclude that An. sinensis is highly zoophilic (cow 61.8%). Malaria is highly unstable (stability index < 0.5) in this area. From these data, vectorial capacity (VC) was determined to be 0.081. In spite of a high human biting rate (ma), malaria transmission potential is very low due to a low human blood index. Therefore, we could conclude that malaria transmission by An. sinensis is resulted by high population density, not by high transmission potential. For this reason, we need more effort to decrease vector population and vector-human contact to eradicate malaria in Korea.
Animals ; Anopheles/*parasitology ; Human ; Insect Vectors ; Korea ; Malaria, Vivax/parasitology/*transmission ; Parity ; Plasmodium vivax/*pathogenicity/physiology ; Population Density

The objectives of the present study were to (1) determine the susceptibility of Anopheles sinensis to Korean isolates of Plasmodium vivax, (2) establish a method to collect large quantities of P. vivax sporozoites for use as antigen in seroepidemiological studies, and (3) investigate the characteristics of Korean isolates of P. vivax sporozoites. Females of Anopheles sinensis were collected at non-epidemic area, Seokwha-ri, Cheongwon-gun and Chungcheongbuk-do using tent-trap methods coupled with dry ice. The females were artificially infected with gametocytes of P. vivax using blood obtained from P. vivax malaria patients. Individual mosquitoes were infected using either a parafilm-covered glass feeding apparatus or were allowed to feed on naturally infected volunteers. Mosquitoes were sacrificed between 16 and 18 days post-feeding and an enzyme-linked immunosorbent assay (ELISA) was used to detect sporozoites. Four (33.4%) of 12 mosquitoes, which were fed on naturally infected volunteers directly, were positive for sporozoites. In cases, the mosquitoes allowed to feed on whole blood which were extract from three different patients with heparin treated vacuutainers using a parafilm-covered glass apparatus. Two of 55 (3.6%) were positive which blood sample was maintained at room temperature for 8 hours, 1 of 68 (1.5%) was positive which blood was maintained at 4 degrees C for 24 hours and 1 of 47 (2.3%) was positive at 4 degrees C for 48 hours. The mean number of sporozoites was estimated about 818 (n = 8; range of 648-1,056) based on optical density values of ELISA.
Animals ; Anopheles/*parasitology ; Enzyme-Linked Immunosorbent Assay ; Human ; Korea ; Plasmodium vivax/isolation & purification/*pathogenicity ; Support, Non-U.S. Gov't