Displaying publications 21 - 40 of 54 in total

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  1. Zheng L, Wang S, Romans P, Zhao H, Luna C, Benedict MQ
    BMC Genet, 2003 Oct 24;4:16.
    PMID: 14577840
    Anopheles gambiae females are the world's most successful vectors of human malaria. However, a fraction of these mosquitoes is refractory to Plasmodium development. L3-5, a laboratory selected refractory strain, encapsulates transforming ookinetes/early oocysts of a wide variety of Plasmodium species. Previous studies on these mosquitoes showed that one major (Pen1) and two minor (Pen2, Pen3) autosomal dominant quantitative trait loci (QTLs) control the melanotic encapsulation response against P. cynomolgi B, a simian malaria originating in Malaysia.
    Matched MeSH terms: Anopheles/parasitology
  2. Chua TH, Manin BO, Vythilingam I, Fornace K, Drakeley CJ
    Parasit Vectors, 2019 Jul 25;12(1):364.
    PMID: 31345256 DOI: 10.1186/s13071-019-3627-0
    BACKGROUND: We investigated the effect of five common habitat types on the diversity and abundance of Anopheles spp. and on the biting rate and time of Anopheles balabacensis (currently the only known vector for Plasmodium knowlesi in Sabah) at Paradason village, Kudat, Sabah. The habitats were forest edge, playground area, longhouse, oil palm plantation and shrub-bushes area. Sampling of Anopheles was done monthly using the human landing catch method in all habitat types for 14 months (October 2013 to December 2014, excluding June 2014). The Anopheles species were morphologically identified and subjected to PCR assay for the detection of Plasmodium parasites. Generalised linear mixed models (GLMM) were applied to test the variation in abundance and biting rates of An. balabacensis in different habitat types.

    RESULTS: A total of 1599 Anopheles specimens were collected in the village, of which about 90% were An. balabacensis. Anopheles balabacensis was present throughout the year and was the dominant Anopheles species in all habitat types. The shrub bushes habitat had the highest Anopheles species diversity while forest edge had the greatest number of Anopheles individuals caught. GLMM analysis indicated that An. balabacensis abundance was not affected by the type of habitats, and it was more active during the early and late night compared to predawn and dawn. PCR assay showed that 1.61% of the tested An. balabacensis were positive for malaria parasites, most of which were caught in oil palm estates and infected with one to two Plasmodium species.

    CONCLUSIONS: The identification of infected vectors in a range of habitats, including agricultural and farming areas, illustrates the potential for humans to be exposed to P. knowlesi outside forested areas. This finding contributes to a growing body of evidence implicating environmental changes due to deforestation, expansion of agricultural and farming areas, and development of human settlements near to forest fringes in the emergence of P. knowlesi in Sabah.

    Matched MeSH terms: Anopheles/parasitology
  3. Yiallouros M, Storch V, Thiery I, Becker N
    J Am Mosq Control Assoc, 1994 Mar;10(1):51-5.
    PMID: 7912261
    Clostridium bifermentans serovar malaysia (C.b.m.) is highly toxic to mosquito larvae. In this study, the following aquatic nontarget invertebrates were treated with high C.b.m. concentrations (up to 1,600-fold the toxic concentration for Anopheles stephensi) to study their susceptibility towards the bacterial toxin: Planorbis planorbis (Pulmonata); Asellus aquaticus (Isopoda); Daphnia pulex (Cladocera); Cloeon dipterum (Ephemeroptera); Plea leachi (Heteroptera); and Eristalis sp., Chaoborus crystallinus, Chironomus thummi, and Psychoda alternata (Diptera). In addition, bioassays were performed with mosquito larvae (Aedes aegypti, Anopheles stephensi, and Culex pipiens). Psychoda alternata larvae were very susceptible, with LC50/LC90 values comparable to those of mosquito larvae (about 10(3)-10(5) spores/ml). The tests with Chaoborus crystallinus larvae showed significant mortality rates at high concentrations, but generally not before 4 or 5 days after treatment. The remaining nontarget organisms did not show any susceptibility. The investigation confirms the specificity of C.b.m. to nematocerous Diptera.
    Matched MeSH terms: Anopheles/parasitology
  4. Vythilingam I
    Trop Biomed, 2010 Apr;27(1):1-12.
    PMID: 20562807 MyJurnal
    Plasmodium knowlesi in humans is life threatening, is on the increase and has been reported from most states in Malaysia. Anopheles latens and Anopheles cracens have been incriminated as vectors. Malaria is now a zoonoses and is occurring in malaria free areas of Malaysia. It is also a threat to eco-tourism. The importance of the vectors and possible control measures is reviewed here.
    Matched MeSH terms: Anopheles/parasitology*
  5. Kittiwattanawong K, Ponlawat A, Boonrotpong S, Nanakorn N, Kongchouy N, Moonmake S, et al.
    Trop Biomed, 2020 Jun 01;37(2):397-408.
    PMID: 33612809
    The Anopheles dirus mosquito is a primary malaria vector that transmits many species of Plasmodium parasites in Thailand and is widely spread across its geographic area. In the current study, the levels of expression of the suppressor of cytokine signaling (SOCS) gene in An. dirus mosquitoes infected with P. vivax were examined. The level of the gene's expression determined by mRNA extraction in An. dirus females (n=2,400) was studied at different times (0, 12, 24, 36, and 48 h after feeding), with different types of blood feeding (non-feeding, parasite-negative blood feeding, parasite-positive blood feeding) and in different parts of the body of mosquito samples (thorax and abdomen). The datasets were analyzed based on their relative expression ratio by the 2-ΔΔCT method and were tested for significant differences with ANOVA. The results showed that the An. dirus SOCS gene was stimulated in the abdomen 12 h and 24 h after blood feeding about three times more highly than in unfed females, with the difference being significant. At 24 h after P. vivax-infected blood feeding, the SOCS gene in the abdomen was expressed more highly than 24 h after parasite-negative blood feeding and expression was almost 36 times higher than in the control group who were not fed blood. However, in the thorax at all times after feeding and non-feeding, there was no expression of the SOCS gene. Therefore, the SOCS gene in An. dirus was most highly expressed 24 h post-feeding with a P. vivax-infected bloodmeal, which indicates that the SOCS gene in the major malaria vector in Thailand plays an important role in its immune system and its response to P. vivax infection.
    Matched MeSH terms: Anopheles/parasitology*
  6. Lee M, Harrison BA, Lewis GE
    Am J Trop Med Hyg, 1990 Apr;42(4):314-9.
    PMID: 2184690 DOI: 10.4269/ajtmh.1990.42.314
    A modified version of the standard 2-site sporozoite enzyme-linked immunosorbent assay (ELISA) using 3,3',5,5'-tetramethylbenzidine (TMB) as the substrate chromogen solution was adapted for rapid detection and identification of Plasmodium falciparum and P. vivax circumsporozoite (CS) proteins. The TMB-ELISA was evaluated using sporozoites from experimentally infected mosquitoes and laboratory colonized uninfected mosquitoes. Our data indicate comparable sensitivity levels between the TMB-ELISA and the standard ELISA, i.e., 50 P. falciparum or P. vivax sporozoites/50 microliters of test solution. Reactions inherent to the method were specific and background reactivity was minimal. The TMB-ELISA is rapid (1 hr), simple, uses a minimal amount of monoclonal antibodies, and is suitable for use in a wide range of laboratories.
    Matched MeSH terms: Anopheles/parasitology
  7. Jeyaprakasam NK, Pramasivan S, Liew JWK, Van Low L, Wan-Sulaiman WY, Ngui R, et al.
    Parasit Vectors, 2021 Apr 01;14(1):184.
    PMID: 33794965 DOI: 10.1186/s13071-021-04689-3
    BACKGROUND: Vector surveillance is essential in determining the geographical distribution of mosquito vectors and understanding the dynamics of malaria transmission. With the elimination of human malaria cases, knowlesi malaria cases in humans are increasing in Malaysia. This necessitates intensive vector studies using safer trapping methods which are both field efficient and able to attract the local vector populations. Thus, this study evaluated the potential of Mosquito Magnet as a collection tool for Anopheles mosquito vectors of simian malaria along with other known collection methods.

    METHODS: A randomized 4 × 4 Latin square designed experiment was conducted to compare the efficiency of the Mosquito Magnet against three other common trapping methods: human landing catch (HLC), CDC light trap and human baited trap (HBT). The experiment was conducted over six replicates where sampling within each replicate was carried out for 4 consecutive nights. An additional 4 nights of sampling was used to further evaluate the Mosquito Magnet against the "gold standard" HLC. The abundance of Anopheles sampled by different methods was compared and evaluated with focus on the Anopheles from the Leucosphyrus group, the vectors of knowlesi malaria.

    RESULTS: The Latin square designed experiment showed HLC caught the greatest number of Anopheles mosquitoes (n = 321) compared to the HBT (n = 87), Mosquito Magnet (n = 58) and CDC light trap (n = 13). The GLMM analysis showed that the HLC method caught significantly more Anopheles mosquitoes compared to Mosquito Magnet (P = 0.049). However, there was no significant difference in mean nightly catch of Anopheles mosquitoes between Mosquito Magnet and the other two trapping methods, HBT (P = 0.646) and CDC light traps (P = 0.197). The mean nightly catch for both An. introlatus (9.33 ± 4.341) and An. cracens (4.00 ± 2.273) caught using HLC was higher than that of Mosquito Magnet, though the differences were not statistically significant (P > 0.05). This is in contrast to the mean nightly catch of An. sinensis (15.75 ± 5.640) and An. maculatus (15.78 ± 3.479) where HLC showed significantly more mosquito catches compared to Mosquito Magnet (P 

    Matched MeSH terms: Anopheles/parasitology*
  8. Bamou R, Mayi MPA, Djiappi-Tchamen B, Nana-Ndjangwo SM, Nchoutpouen E, Cornel AJ, et al.
    Parasit Vectors, 2021 Oct 11;14(1):527.
    PMID: 34635176 DOI: 10.1186/s13071-021-04950-9
    The expansion of mosquito-borne diseases such as dengue, yellow fever, and chikungunya in the past 15 years has ignited the need for active surveillance of common and neglected mosquito-borne infectious diseases. The surveillance should be designed to detect diseases and to provide relevant field-based data for developing and implementing effective control measures to prevent outbreaks before significant public health consequences can occur. Mosquitoes are important vectors of human and animal pathogens, and knowledge on their biodiversity and distribution in the Afrotropical region is needed for the development of evidence-based vector control strategies. Following a comprehensive literature search, an inventory of the diversity and distribution of mosquitoes as well as the different mosquito-borne diseases found in Cameroon was made. A total of 290 publications/reports and the mosquito catalogue website were consulted for the review. To date, about 307 species, four subspecies and one putative new species of Culicidae, comprising 60 species and one putative new species of Anopheles, 67 species and two subspecies of Culex, 77 species and one subspecies of Aedes, 31 species and one subspecies of Eretmapodites, two Mansonia, eight Coquillettidia, and 62 species with unknown medical and veterinary importance (Toxorhynchites, Uranotaenia, Mimomyia, Malaya, Hodgesia, Ficalbia, Orthopodomyia, Aedeomyia, and Culiseta and Lutzia) have been collected in Cameroon. Multiple mosquito species implicated in the transmission of pathogens within Anopheles, Culex, Aedes, Eretmapodites, Mansonia, and Coquillettidia have been reported in Cameroon. Furthermore, the presence of 26 human and zoonotic arboviral diseases, one helminthic disease, and two protozoal diseases has been reported. Information on the bionomics, taxonomy, and distribution of mosquito species will be useful for the development of integrated vector management programmes for the surveillance and elimination of mosquito-borne diseases in Cameroon.
    Matched MeSH terms: Anopheles/parasitology
  9. Marin-Mogollon C, van Pul FJA, Miyazaki S, Imai T, Ramesar J, Salman AM, et al.
    Malar J, 2018 Aug 09;17(1):288.
    PMID: 30092798 DOI: 10.1186/s12936-018-2431-1
    BACKGROUND: Rodent malaria parasites where the gene encoding circumsporozoite protein (CSP) has been replaced with csp genes from the human malaria parasites, Plasmodium falciparum or Plasmodium vivax, are used as pre-clinical tools to evaluate CSP vaccines in vivo. These chimeric rodent parasites produce sporozoites in Anopheles stephensi mosquitoes that are capable of infecting rodent and human hepatocytes. The availability of chimeric P. falciparum parasites where the pfcsp gene has been replaced by the pvcsp would open up possibilities to test P. vivax CSP vaccines in small scale clinical trials using controlled human malaria infection studies.

    METHODS: Using CRISPR/Cas9 gene editing two chimeric P. falciparum parasites, were generated, where the pfcsp gene has been replaced by either one of the two major pvcsp alleles, VK210 or VK247. In addition, a P. falciparum parasite line that lacks CSP expression was also generated. These parasite lines have been analysed for sporozoite production in An. stephensi mosquitoes.

    RESULTS: The two chimeric Pf-PvCSP lines exhibit normal asexual and sexual blood stage development in vitro and produce sporozoite-containing oocysts in An. stephensi mosquitoes. Expression of the corresponding PvCSP was confirmed in oocyst-derived Pf-PvCSP sporozoites. However, most oocysts degenerate before sporozoite formation and sporozoites were not found in either the mosquito haemocoel or salivary glands. Unlike the chimeric Pf-PvCSP parasites, oocysts of P. falciparum parasites lacking CSP expression do not produce sporozoites.

    CONCLUSIONS: Chimeric P. falciparum parasites expressing P. vivax circumsporozoite protein fail to produce salivary gland sporozoites. Combined, these studies show that while PvCSP can partially complement the function of PfCSP, species-specific features of CSP govern full sporozoite maturation and development in the two human malaria parasites.

    Matched MeSH terms: Anopheles/parasitology*
  10. Sabbatani S, Fiorino S, Manfredi R
    Braz J Infect Dis, 2010 May-Jun;14(3):299-309.
    PMID: 20835518
    After examining the most recent scientific evidences, which assessed the role of some malaria plasmodia that have monkeys as natural reservoirs, the authors focus their attention on Plasmodium knowlesi. The infective foci attributable to this last Plasmodium species have been identified during the last decade in Malaysia, in particular in the states of Sarawak and Sabah (Malaysian Borneo), and in the Pahang region (peninsular Malaysia). The significant relevance of molecular biology assays (polymerase chain reaction, or PCR, performed with specific primers for P. knowlesi), is underlined, since the traditional microscopic examination does not offer distinguishing features, especially when the differential diagnosis with Plasmodium malariae is of concern. Furthermore, Plasmodium knowlesi disease may be responsible of fatal cases, since its clinical presentation and course is more severe compared with those caused by P. malariae, paralleling a more elevated parasitemia. The most effective mosquito vector is represented by Anopheles latens; this mosquito is a parasite of both humans and monkeys. Among primates, the natural hosts are Macaca fascicularis, M. nemestina, M. inus, and Saimiri scirea. When remarking the possible severe evolution of P. knowlesi malaria, we underline the importance of an early recognition and a timely management, especially in patients who have their first onset in Western Hospitals, after journeys in Southeast Asian countries, and eventually participated in trekking excursions in the tropical forest. When malaria-like signs and symptoms are present, a timely diagnosis and treatment become crucial. In the light of its emerging epidemiological features, P. knowlesi may be added to the reknown human malaria parasites, whith includes P. vivax, P. ovale, P. malariae, and P. falciparum, as the fifth potential ethiologic agent of human malaria. Over the next few years, it will be mandatory to support an adequate surveillance and epidemiological network. In parallel with epidemiological and health care policy studies, also an accurate appraisal of the clinical features of P. knowlesi-affected patients will be strongly needed, since some preliminary experiences seem to show an increased disease severity, associated with increased parasitemia, in parallel with the progressive increase of inter-human infectious passages of this emerging Plasmodium.
    Matched MeSH terms: Anopheles/parasitology*
  11. Musa MI, Shohaimi S, Hashim NR, Krishnarajah I
    Geospat Health, 2012 Nov;7(1):27-36.
    PMID: 23242678
    Malaria remains a major health problem in Sudan. With a population exceeding 39 million, there are around 7.5 million cases and 35,000 deaths every year. The predicted distribution of malaria derived from climate factors such as maximum and minimum temperatures, rainfall and relative humidity was compared with the actual number of malaria cases in Sudan for the period 2004 to 2010. The predictive calculations were done by fuzzy logic suitability (FLS) applied to the numerical distribution of malaria transmission based on the life cycle characteristics of the Anopheles mosquito accounting for the impact of climate factors on malaria transmission. This information is visualized as a series of maps (presented in video format) using a geographical information systems (GIS) approach. The climate factors were found to be suitable for malaria transmission in the period of May to October, whereas the actual case rates of malaria were high from June to November indicating a positive correlation. While comparisons between the prediction model for June and the case rate model for July did not show a high degree of association (18%), the results later in the year were better, reaching the highest level (55%) for October prediction and November case rate.
    Matched MeSH terms: Anopheles/parasitology*
  12. Vythilingam I, Sidavong B, Chan ST, Phonemixay T, Vanisaveth V, Sisoulad P, et al.
    Trans R Soc Trop Med Hyg, 2005 Nov;99(11):833-9.
    PMID: 16112154
    Surveys were conducted in malaria-endemic villages in the southern province of Attapeu, Lao PDR during various seasons over a 3-year period. All-night mosquito landing collections, blood surveys and a case-control study were conducted. Plasmodium falciparum was the predominant species, and slide positivity rates were higher during the transition/dry season compared with the wet season. Anopheles dirus A was found to be the primary vector, and sporozoite rates were highest during the transition/dry season. Anopheles dirus was found to be endophagic and endophilic. Not using insecticide-treated bed nets, houses close to breeding sites and sleeping away from home were risk factors associated with malaria.
    Matched MeSH terms: Anopheles/parasitology
  13. Vythilingam I, Nitiavathy K, Yi P, Bakotee B, Hugo B, Singh B, et al.
    PMID: 10928352
    Dried Anopheles farauti mosquitos caught in Solomon Islands in 1990 were examined for malaria sporozoites by ELISA and nested polymerase chain reaction (PCR). Only heads and thoraces were used. Plasmodium genus-specific nested PCR amplifications were carried out on all samples. Of the 402 pools of mosquitos that were processed, 30 were positive for malaria. Nest 1 products of positive samples were subjected to further PCR amplifications with species-specific primers for P. falciparum and P. vivax. Twenty pools were positive for P. vivax by PCR while only 7 were positive by ELISA. For P. falciparum 2 pools were positive by both ELISA and PCR, and one of these was a pool which was positive for P. vivax by PCR and ELISA. Thus the sensitivity of PCR for P. vivax was 100% while the specificity was 96.7%. For P. falciparum the sensitivity and specificity were 100%. The PCR technique is highly sensitive and can be used on dried mosquitos which makes it a valuable tool for determining sporozoite rates of mosquitos, even in remote areas.
    Matched MeSH terms: Anopheles/parasitology*
  14. Rahman WA, Che'Rus A, Ahmad AH
    PMID: 9561615
    Until today, malaria is still one of the most important diseases in Malaysia. This is because Malaysia is located within the equatorial zone with high temperatures and humidities, usually important for the transmission of malaria. The number of malaria cases were estimated to be around 300,000 before the launching of the Malaria Eradication Program (MEP). The program was successful in reducing the numbers progressively during the 1967-1982 period. During the period 1980-1991, the highest number of malaria cases recorded for the country was 65,283 in 1989 (16,902 in Peninsular Malaysia, 47,545 in Sabah and 836 in Sarawak) whilst the lowest was 22,218 (10,069 in Peninsular Malaysia, 11,290 in Sabah and 859 in Sarawak) in 1983. In Malaysia, there are 434 species of mosquitos, representing 20 genera. Of these, 75 species are Anopheles that comprise of 2 subgenus, i.e. Anopheles and Cellia. Of the 75 species, only 9 have been reported as vectors: An. maculatus, An balabacensis, An. dirus, An. letifer An. campestris, An. sundaicus, An. donaldi, An. leucophyrus and An. flavirostris. The behavior, seasonal abundance, biting activities and breeding sites of these species are discussed.
    Matched MeSH terms: Anopheles/parasitology*
  15. Zahedi M, White GB
    Trop. Med. Parasitol., 1994 Mar;45(1):27-32.
    PMID: 8066378
    The filaria vector competence of Anopheles stephensi was compared with Brugia-susceptible Aedes aegypti Liverpool strain, An. gambiae Badagry Lagos strain and An. dirus Perlis Malaysia strain. An. stephensi ingested more Brugia pahangi microfilariae, had the highest infectivity rate and yielded more infective mosquitoes than the other two anopheline species. The overall vector competence of An. stephensi was 0.13 times that of Ae. aegypti, 0.62 times that of An. gambiae and 2.17 times that of An. dirus. However, heavy mortality among infected An. stephensi in the present investigation indicates that the filaria vectorial capacity of the mosquito might be limited epidemiologically. The relationship between filaria vector competence and mosquito foregut armature is discussed. It was observed that the relative vector competence of the three anopheline species tested was in the same order as their relative degrees of armature elaboration. The converse would be expected if foregut armatures really give partial protection to the mosquitoes against filarial infection. It is suggested that high host microfilariae density favours larval survival proportional to the degree of armature development in Anopheles (Cellia) species.
    Matched MeSH terms: Anopheles/parasitology*
  16. Brown R, Chua TH, Fornace K, Drakeley C, Vythilingam I, Ferguson HM
    PLoS Negl Trop Dis, 2020 09;14(9):e0008617.
    PMID: 32886679 DOI: 10.1371/journal.pntd.0008617
    The zoonotic malaria parasite, Plasmodium knowlesi, is now a substantial public health problem in Malaysian Borneo. Current understanding of P. knowlesi vector bionomics and ecology in Sabah comes from a few studies near the epicentre of human cases in one district, Kudat. These have incriminated Anopheles balabacensis as the primary vector, and suggest that human exposure to vector biting is peri-domestic as well as in forest environments. To address the limited understanding of vector ecology and human exposure risk outside of Kudat, we performed wider scale surveillance across four districts in Sabah with confirmed transmission to investigate spatial heterogeneity in vector abundance, diversity and infection rate. Entomological surveillance was carried out six months after a cross-sectional survey of P. knowlesi prevalence in humans throughout the study area; providing an opportunity to investigate associations between entomological indicators and infection. Human-landing catches were performed in peri-domestic, farm and forest sites in 11 villages (3-4 per district) and paired with estimates of human P. knowlesi exposure based on sero-prevalence. Anopheles balabacensis was present in all districts but only 6/11 villages. The mean density of An. balabacensis was relatively low, but significantly higher in farm (0.094/night) and forest (0.082/night) than peri-domestic areas (0.007/night). Only one An. balabacensis (n = 32) was infected with P. knowlesi. Plasmodium knowlesi sero-positivity in people was not associated with An. balabacensis density at the village-level however post hoc analyses indicated the study had limited power to detect a statistical association due low vector density. Wider scale sampling revealed substantial heterogeneity in vector density and distribution between villages and districts. Vector-habitat associations predicted from this larger-scale surveillance differed from those inferred from smaller-scale studies in Kudat; highlighting the importance of local ecological context. Findings highlight potential trade-offs between maximizing temporal versus spatial breadth when designing entomological surveillance; and provide baseline entomological and epidemiological data to inform future studies of entomological risk factors for human P. knowlesi infection.
    Matched MeSH terms: Anopheles/parasitology*
  17. Krishnan J, Mathiarasan L
    J Vector Borne Dis, 2019 1 9;55(3):189-196.
    PMID: 30618444 DOI: 10.4103/0972-9062.249127
    Background & objectives: : Increase of vector-borne diseases (VBDs) in India has posed a question on the situation in Lakshadweep Islands, where VBDs are reported from time-to-time. The present investigation was aimed to assess the faunastic situation of the prevailing vectors along with their breeding sites in different islands of the Lakshadweep.

    Methods: : Extensive surveys were carried out from November 2017 to January 2018 (post-monsoon season) randomly in the nine inhabited islands of Lakshadweep for conducting faunastic studies on mosquitoes and to know the basic binomics like breeding and resting preference of mosquitoes. The study islands included, Kavaratti, Agatti, Chetlat, Bitra, Amini, Kadmath, Andrott, Kalpeni and Kiltan. Both immature and adult collections were carried out by standard/appropriate sampling techniques. The obtained data were calculated and analysed in terms of different entomological indices.

    Results: : A total of 3356 mosquitoes were collected during the study period which comprised of 16 species from nine genera. Out of the 16 species, six belonged to mosquito vectors. The collection included malaria vector, Anopheles stephensi; Japanese encephalitis vector, Culex tritaeniorhynchus; Bancroftian filariasis vector, Cx. quinquefasciatus; Brugian filariasis vector, Mansonia uniformis; and dengue and chikungunya vectors, Stegomya albopicta and St. aegypti. Stegomya albopicta was the most predominant species observed constituting 54% of the catch, followed by Cx. quinquefasciatus, An. stephensi, Cx. tritaeniorhynchus, and St. aegypti constituting 10.5, 6, 3 and 1.2%, respectively. Apart from vector species many non-vectors such as Heizmannia chandi, An. subpictus, An. varuna, Cx. sitiens, Cx. minutissimus, Cx. rubithoracis, Fredwardsius vittatus, Lutzia fuscana, Malaya genurostris and Armigeres subalbatus were also present in the study area. In Kavaratti Island, the capital of Lakshadweep, a non-vector species of sandfly, Sergentomyia (Parrotomyia) babu was observed during the indoor resting collection. The major breeding sites which supported various mosquito species included, discarded plastic containers, tree holes, open sintex tanks (water storage tanks), unused wells, discarded tyres, discarded iron pots, unused and damaged boats, cement tanks, pleated plastic sheets, coral holes, pits and irrigation canals, discarded washing machines, and Colocasia plant leaf axils. Breteau index ranged between 65.3 and 110, CI ranged between 63.64 and 72.41; and HI ranged between 38.46 and 70 among the various islands.

    Interpretation & conclusion: : Entomological indices such as house index (HI), breteau index (BI) and pupal index (PI) were high in all the nine islands and exceeded the threshold levels specified by WHO, indicating high risk for dengue virus transmission in case of outbreaks. Occurrence of vector as well as non-vector species indicates that the global change in climate is causing notable changes in terms of breeding of vector and non-vector species in the islands. With the reported cases of VBDs and the presence of vectors species in Lakshadweep Islands, a stringent control measure needs to be implemented at the Lakshadweep Islands.

    Matched MeSH terms: Anopheles/parasitology
  18. Davidson G, Chua TH, Cook A, Speldewinde P, Weinstein P
    Ecohealth, 2019 12;16(4):594-610.
    PMID: 30675676 DOI: 10.1007/s10393-019-01395-6
    Defining the linkages between landscape change, disease ecology and human health is essential to explain and predict the emergence of Plasmodium knowlesi malaria, a zoonotic parasite residing in Southeast Asian macaques, and transmitted by species of Anopheles mosquitos. Changing patterns of land use throughout Southeast Asia, particularly deforestation, are suggested to be the primary drivers behind the recent spread of this zoonotic parasite in humans. Local ecological changes at the landscape scale appear to be increasing the risk of disease in humans by altering the dynamics of transmission between the parasite and its primary hosts. This paper will focus on the emergence of P. knowlesi in humans in Malaysian Borneo and the ecological linkage mechanisms suggested to be playing an important role.
    Matched MeSH terms: Anopheles/parasitology*
  19. Vythilingam I, Phetsouvanh R, Keokenchanh K, Yengmala V, Vanisaveth V, Phompida S, et al.
    Trop Med Int Health, 2003 Jun;8(6):525-35.
    PMID: 12791058
    A longitudinal study was conducted on the prevalence of Anopheles in three malaria endemic villages in Sekong province, in the southern region of Lao PDR, from August 2000 to October 2001. All night, human landing collections took place in August and October 2000 and April and October 2001, and blood smears were taken for malaria parasites during the same period. Mosquitoes were tested for sporozoite antigen using enzyme-linked immunosorbent assay. In August 2000 (wet season) and April 2001 (dry season) the ovaries of the mosquitoes were examined for parity. A total of 16 species of Anopheles were caught in the study sites of which An. dirus A, An. maculatus sl and An. jeyporiensis were positive for sporozoites. The entomological inoculation rate (EIR) ranged from 0.06 to 0.25. There was a good correlation between EIR and vectorial capacity in the wet season, especially in Pai Mai where the prevalence of malaria was also high during the wet seasons (11.8 and 10.53). An. dirus A showed ambivalence in their choice of feeding as approximately 50% attacked man indoors and an equal proportion outdoors. An dirus A was the main vector in Pai Mai. The parous rate did not significantly differ between the wet and dry season, although it was higher in the dry season. In Takaio the parasite prevalence ranged from 8.7% (dry season) to 37.1% (wet season) and An. jeyporiensis was the vector, and the risk of infection was 0.85 in the dry season while 0.99 in the wet season. In Toumgno An. maculatus sl was the vector and infection was found only in August and October 2000. However, malaria prevalence ranged from 9.69 to 20.4% and was equally high in the dry season. Cattle were also present close to the houses in all the villages and this might be a contributory factor in the prevalence of malaria.
    Matched MeSH terms: Anopheles/parasitology*
  20. Özbilgin A, Çavuş İ, Yıldırım A, Gündüz C
    Mikrobiyol Bul, 2016 Jul;50(3):484-90.
    PMID: 27525405
    Plasmodium knowlesi is now added to the known four Plasmodium species (P.vivax, P.falciparum, P.malariae, P.ovale) as a cause of malaria in humans because of the recent increasing rate of cases reported from countries of southeastern Asia. P.knowlesi which infects macaque monkeys (Macaca fascicularis and M.nemestrina) is transmitted to humans especially by Anopheles leucosphyrus and An.hackeri mosquitos. First human cases of P.knowlesi malaria have been detected in Malaysia which have reached high numbers in recent years and also have been reported from countries of Southeast Asia such as Thailand, Philippines, Myanmar, Singapore and Vietnam. However the number of cases reported from western countries are rare and limited only within voyagers. This report is the first presentation of an imported case of P.knowlesi malaria in Turkey and aims to draw attention to the point that it could also be detected in future. A 33-year-old male patient from Myanmar who has migrated to Turkey as a refugee, was admitted to a health center with the complaints of fever with a periodicity of 24 hours, headache, fatigue, cough, sore throat, anorexia, myalgia and arthralgia. He was prediagnosed as upper respiratory tract infection, however because of his periodical fever and background in Myanmar, thick and thin blood films were prepared and sent to our laboratory for further examinations. Microscopic examination of the thin blood films revealed erythrocytic stages compatible with P.knowlesi (three large early trophozoites in an erythrocyte, three late trophozoites with compact view, and three late band-form trophozoites). Upon this, both real-time polymerase chain reaction (Rt-PCR) targeting the small subunit ribosomal RNA (SSU-rRNA) genes of Plasmodium genus and DNA sequence analysis targeting P.knowlesi rRNA gene were performed. As a result, the suspected identification of P.knowlesi by microscopy was confirmed by Rt-PCR and DNA sequencing. The patient was treated with chloroquine and primaquine combination and in the follow-up on the seventh day after the treatment, his parasitemia and symptoms had ceased. Although there were some previous reports concerning about imported patients infected with different Plasmodium species in our country, no cases of P.knowlesi have been reported. This first case presented here emphasizes the occurence of P.knowlesi malaria in Turkey hereinafter due to the increasing number of refugees.
    Matched MeSH terms: Anopheles/parasitology
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