Morphometric and morphological appraisal of the eggs of Anopheles stephensi (Diptera: Culicidae) from India.

BACKGROUND & OBJECTIVES: Anopheles stephensi is one of the most important urban malaria vectors in India and contribute about 12% of total malaria cases. An. stephensi has three ecological variants; type, intermediate and mysorensis that can be differentiated on the basis of differences in number of ridges on egg float and on the basis of spiracular indices. Because of its anthropophilic nature the 'type' form is an efficient malaria vector. In the present study, the egg surface morphometry and morphology of An. stephensi 'type' form was studied and detail distinguish- ing characters were recorded for its correct identification. METHODS: Eggs of An. stephensi 'type' form were studied by scanning electron microscopy (SEM) after sputter- coating with gold. In total 23 egg characters were analysed morphologically and morphometrically, which included egg attributes, deck attributes, ventral tubercles, micropyle and float attributes. RESULTS: The dorsal surface of the egg of 'type' form was curved while the ventral surface was concave and both anterior and posterior ends were blunt. The average length and width of egg was 473.94 + 11.18 and 154.69 + 2.66 µm respectively. The number of float ribs observed was 20.33 ± 0.33. The maximum length of float was found to be 246.57 + 15.27 µm, whereas maximum width was 87.16 + 3.83 µm. INTERPRETATION & CONCLUSION: The present study has generated some important data which is specific to An. Stephensi 'type' form and provided significant morphological and morphometric standards for its correct identification. This information could be useful in differentiation of An. stephensi 'type' form from other ecological forms of the same species as well as other species of Anopheles.

Subchronic dermal exposure to T-2 toxin produces cardiac toxicity in experimental Wistar rats.

Our study aimed to determine the cardiac toxicities of T-2 toxin, a representative mycotoxin that frequently contaminates maize, cereals, and other agricultural products, harvested and stored under damp and cold conditions. Dermal exposure to T-2 toxin caused severe cardiotoxicity in experimental Wistar rats. Electrocardiography studies showed the conduction abnormalities including prolongation of the QT and corrected QT interval, shortening of the PR interval, and tachycardia. Biochemical studies also reported the toxicity of T-2 toxin. T-2 toxin induced acute cardiotoxicity in rats and characterized by significant (p < 0.05) elevation of serum troponin I, creatine kinase (CK) isoenzyme MB, CK isoenzyme NAC, and lactate dehydrogenase as compared to control rats. It is concluded that cardiotoxicity effects of T-2 toxin are thought to be due to direct action on electrocardiac potentials and biochemical changes.

Phylogenetic Characterization of a Novel Insect-Specific Flavivirus Detected in a Culex Pool, Collected from Assam, India.

OBJECTIVE: We report the phylogenetic characterization of a unique flavivirus sequence detected in a wild Culex tritaeniorhynchus mosquito pool, collected from the northeast Indian state of Assam. METHODS: DNA and RNA were extracted from field-collected mosquito pools. Extracts were subjected to PCR and reverse transcriptase PCR amplification using universal and type-specific primers for direct detection of flavivirus-specific viral nucleic acids. An amplified flavivirus nonstructural protein 5 (NS5) genetic region was sequenced and BLAST searched, and phylogenetic analyses performed with reference sequences retrieved from GenBank. RESULTS: Phylogenetic analyses revealed the sequence to be related to insect-specific flaviviruses (ISFs) of the genus Flavivirus, family Flaviviridae. Despite being related to the Palm Creek virus (PCV; an ISF very recently reported from Northern Australia), the present sequence (provisionally named Assam virus) was found to be highly divergent from PCV and other ISF sequences available in GenBank. The partial NS5 sequence analysis demonstrated low nucleotide sequence identity (66-77%) with known ISFs reported from other parts of the globe. CONCLUSION: Findings of this study suggest the presence of a candidate novel ISF - the first to be reported from India.

Absence of asymptomatic malaria in a cohort of 133 individuals in a malaria endemic area of Assam, India.

BACKGROUND: Malaria in northeast India affects children and adults annually. The number of malaria cases reported has declined over the past few years. Nevertheless, it is not clear whether there is an actual decline in parasitaemia or whether asymptomatic malaria infections are on the rise, especially in forested and forest-fringed areas. Asymptomatic malaria forms a parasite reservoir that acts as an epicentre for malaria spread during high-transmission season. Therefore it is important to understand the quantum of asymptomatic malaria infections among the vulnerable population. METHOD: Four forest fringed historically malaria endemic villages were selected for the study. A total of 133 individuals without a fever history in the past four weeks were tested for malaria parasite using rapid diagnostic test (RDT), microscopy and polymerase chain reaction (PCR) assay during January - February 2014. Indoor resting Anopheles vectors were collected, identified and tested for sporozoite using VectorTest™ panel assay during October 2013 to March 2014, which is a low transmission season for malaria. Social and demographic data were recorded during the study. RESULTS: Mean age (± SEM) of the participants was 16.1 ± 1.2 years (95 % CI: 13.8-18.4). All participants (100 %) reported to use mosquito nets. Altogether, 43.6 % of participants had education below primary level and only 9 % reported a travel history during the past four weeks. All RDT, microscopy and PCR assays were found negative indicating no asymptomatic malaria parasitaemia. Seven known malaria vector species namely, Anopheles nivipes, An. minimus, An. annularis, An. vagus, An. aconitus, An. philippinensis and An. culicifacies, were recorded in the present study. VectorTest™ sporozoite panel assay conducted on 45 pools (N = 224) of vector mosquitoes were found negative for Plasmodium sporozoite. DISCUSSION: Northeastern states of India report asymptomatic malaria parasitemia along with high malaria transmission. An. minimus and An. dirus are recognised as efficient vectors, but An. culicifacies, An. philippinensis and An. annularis also play role in malaria transmission. Currently all participants were found negative for asymptomatic malaria, however the small sample size may restrict the scope of present results to the population living in more remote areas. CONCLUSION: No cases of asymptomatic malaria infections parasitaemia was found in the present study conducted during a low transmission season indicating that asymptomatic malaria parasitaemia may not be prevalent in the region. Mosquito specimens were tested negative for the malaria sporozoites. Study findings encourage the ongoing malaria intervention efforts and recommends similar investigations in different ecological areas involving large populations.

Isolation and characterization of Vagococcus sp from midgut of Culex quinquefasciatus (Say) mosquito.

BACKGROUND & OBJECTIVES: Mosquito gut is a rich source of microorganisms. These microorganisms exhibit close association and contribute various physiological processes taking place in mosquito gut. The present study is aimed to characterize two bacterial isolates M19 and GB11 recovered from the gut of Culex quinquefasciatus mosquito collected from Bhuj and Jamnagar districts of Gujarat, India. METHODS: Both the strains were characterized using polyphasic approach including, phenotypic characterization, whole cell protein profiling and sequencing of 16S rRNA gene and groESL region. RESULTS: Sequences of 16S rRNA gene of M19 and GB11 were 99% similar to Vagococcus carniphilus and Vagococcus fluvialis. But phenotypic profile, whole cell protein profile and sequence of groESL region of both isolates were found to be similar to V. fluvialis. CONCLUSION: Based on phenotypic, genotypic and protein profiling, both the strains were identified as V. fluvialis. So far this species was known from domestic animals and human sources only. This is the first report of V. fluvialis inhabiting midgut of Cx. quinquefasciatus mosquito collected from Arabian sea coastal of India.

Deoxynivalenol induces cytotoxicity and genotoxicity in animal primary cell culture.

Deoxynivalenol (DON), a mycotoxin produced by Fusarium graminearum, is widely found as a contaminant of food. DON is responsible for a wide range of toxic activities, including gastro-intestinal, lymphoid, bone-marrow and cardiotoxicity. But, the complete explorations of toxicity in terms of hepatotoxicity, nephrotoxicity, cytotoxicity and genotoxicity as well have not been documented well. Again, the mechanisms through which DON damages the DNA and promotes cellular toxicity are not well established. Considering the above fact, this research article is focused on the effects of DON-induced toxicities on experimental animal model as well as its effects on cellular level via various toxicological investigations. DON treatment showed cytotoxicity and DNA damage. Further, flow cytometric analysis of hepatocytes showed cellular apoptosis, suggesting that DON-induced hepatotoxicity is, may be partly, mediated by apoptosis. Moreover, significant differences were found in each haematology and clinical chemistry value, either (p > 0.05). No abnormality of any organ was found during histopathological examination. Hence, it can be concluded that DON induces oxidative DNA damage and increases the formation of centromere positive micronuclei due to aneugenic activity.

Detection of human papillomavirus in women attending Pap cervical screening camp at a peripheral hospital of North-Eastern India.

Human papillomavirus (HPV) associated cervical cancer is the leading cause of deaths in India. However, cytological/HPV screening may result in early detection of cervical cancer, resulting in early treatment and reduced mortality. Although reports related to general population is available, data on HPV prevalence among women attending AFMS health care facilities is scarce. Cervical samples were collected for cytological staining by Pap test and molecular detection by PCR, genotyping by HPV specific primers and sequencing. Apart from finding of atypical cells of undetermined significance (ASCUS) in one subject, no evidence of malignancy was observed. A high prevalence of HPV was found in this study group, which was intermediate between previous reports from general population and cervical cancer patients. All the subjects had infection of high risk HPV type16. HPV prevalence was found similar between different age groups. Although, none of the study subjects had malignant changes, but due to high prevalence of high risk HPV infection and other associated risk factors, these subjects might be at an elevated risk of developing cervical cancer. Regular follow-up of these patients who were detected HPV positive are required to screen for cervical malignancy.

Genetic polymorphism and amino acid sequence variation in Plasmodium falciparum GLURP R2 repeat region in Assam, India, at an interval of five years.

BACKGROUND: The R2 repeat region of GLURP has been reported as a good genetic marker for Plasmodium falciparum genotyping. Proper knowledge of the extent and nature of P. falciparum genetic diversity using highly immunogenic R2 repeat region in malaria-endemic areas is a crucial element to understand various aspects related to immunity acquisition and disease pathogenesis. METHODS: Population diversity of P. falciparum GLURP and amino acid sequence repeats in GLURP R2 region was studied in malaria-endemic Assam state, northeast India and compared at an interval of five years during 2005 (Group-A) and 2011 (Group-B). RESULTS: Of the 66 samples, a total of 55 samples showed positive PCR bands for GLURP R2 region and altogether ten types of alleles with size ranging from 501 bp to 1,050 bp (50 bp bin) were observed and coded as genotypes I-X. In Group-A (n = 29), 24 samples were found infected with single, four with double and one with triple P. falciparum genotype, while in Group-B (n = 26), single genotype was found in 23 samples, double in two samples and triple in one sample. Genotype IV showed significant increase (p = 0.002) during 2011 (Group-B). Genotypes I to V were more common in Group-B (62%), however genotypes VI to X were more frequently distributed in Group-A. The expected heterozygosity was found slightly higher in Group-A (HE = 0.87) than Group-B (HE = 0.85), whereas multiplicity of infection (MOI) in Group-A (MOI = 1.21 ± 0.49) and Group-B (MOI = 1.12 ± 0.43) did not display significant variation. The amino acid repeat sequence unit (AAU) DKNEKGQHEIVEVEEILPE (called 'a') was more frequent in the well-conserved part of R2 repeat region. CONCLUSION: The present study is the first extensive study in India which has generated substantial data for understanding the type and distribution of naturally evolved genetic polymorphism at amino acid sequence level in GLURP R2 repeat region in P. falciparum. There was decrease in the PCR amplicon size as well as the number of AAU [amino acid repeat unit] in Group-B displaying the bottleneck effect. The present study described a new type of AAU 'd' which varied from the other previous known AAUs.

Spatiotemporal distribution of dengue vectors & identification of high risk zones in district Sonitpur, Assam, India.

BACKGROUND & OBJECTIVES: Dengue is an arboviral disease of public health importance in many parts of India and recently many cases have been reported from northeastern India. Aedes mosquitoes, which are the vectors of dengue, are widely prevalent in the region. A study was initiated in Sonitpur district of Assam to understand the spatiotemporal distribution and seasonal prevalence of dengue vectors and to identify the high risk zones. METHODS: Ovitrap surveys were conducted in three randomly selected villages under each of the eight public health centres (PHC) in district Sonitpur of Assam, northeastern India during March 2011-February 2012. Three risk zones (high, medium and low) were identified on the basis of per trap density of Aedes mosquitoes. Meteorological data were collected to study the temporal distribution of dengue vectors. RESULTS: Aedes albopictus (99.3%) was the predominant dengue vector followed by Ae. aegypti (0.7%) recorded in the ovitraps. The highest vector density was observed during the post-monsoon (60.1±18 per trap) while the lowest during the winter (7.6±4.9 per trap) and the season-wise differences in the vector density were significant (P=0.005). Maximum temperature (correlation coefficient, r=0.45) and minimum temperature (r=0.408) showed the highest positive correlation with the vector density, whereas the number of rainy days showed high positive correlation (r=0.185) than the total rainfall (r=0.117). The high risk zone (Dekhiajuli, Behali, Bihaguri and Gohpur PHC) as indicated by the high larval densities of dengue vectors, 45.3±18, 42.1±22.3, 36.9±29.1, 35.3±22.6 per trap, respectively, was validated by dengue epidemiological data collected during 2012. INTERPRETATION & CONCLUSIONS: Yearlong monitoring of dengue vectors was done for the first time in this region. Monthly maximum temperature and the number of rainy days could be used for the prediction of larval density of Aedes mosquitoes. The identification high dengue risk zones would help in adopting targeted interventions for disease management in future.

Iron-rich drinking water and ascorbic acid supplementation improved hemolytic anemia in experimental Wistar rats.

Anemia is a frequent problem in both the primary and secondary health care programs. In contrast, most areas of northeast India are vulnerable to iron toxicity. In the present study, we documented the effect of administration of iron rich water on hemolytic anemia in a Wistar rats' animal model. Hemolytic anemia was induced by phenyl hydrazine through intraperitoneal route and diagnosed by the lowering of blood hemoglobin. After inducing the hemolytic anemia, 24 Wistar rats (n = 6 in four groups) were randomly assigned to 1 mg/l, 5 mg/l, and 10 mg/l ferric oxide iron along with 1 mg/ml ascorbic acid administered through drinking water; a control group was treated with iron-free water. The hematological and biochemical parameters, iron levels in liver, spleen, and kidney were estimated after 30 d of treatment. In the group treated with 5 mg/l iron and ascorbic acid, a significant increase of serum iron and ferritin, and a decrease of TIBC (total iron binding capacity) were observed without changes in other biochemical parameters and histopathological findings. However, in the group treated with 10 mg/l iron and ascorbic acid, hematological changes with significantly higher values for white blood cell count, serum glutamic phospho transaminase, serum glutamic oxaloacetic transaminase, alkaline phosphatase, glucose, splenic, and liver iron content, indicate potential toxicity at this supplementation level. Data suggest that the optimum concentration of iron (5 mg/l) and ascorbic acid solution may improve anemic conditions and may be therapeutically beneficial in the treatment of iron deficiency anemia without any negative impact, while 10 mg/l in drinking water seems to be the threshold for the initiation of toxicity.

Acute and subchronic dermal toxicity of Vitex negundo essential oil.

Vitex negundo is a common herb in different herbal formulation. The potential acute and sub-chronic dermal toxicities were evaluated as per OECD (Organization for Economic Cooperation and Development) guidelines 402 and 411, respectively. Both sexes of Wistar rats were exposed to Vitex negundo oil of 2000 mg/kg body weight for acute dermal toxicity, whereas in the dermal sub-chronic toxicity study, rats were exposed to Vitex negundo oil 250, 500 and 1000 mg/kg body weight, respectively, for five times a week for 90 d. In acute and sub-chronic toxicity studies, all animals were normal without any behavioral, serum biochemistry, hematology, necroscopical and histopathological changes. The no observed effect level (NOEL) and no observed adverse effect level (NOAEL) of Vitex negundo oil were 250 and 1000 mg/kg/day, respectively. Vitex negundo oil is under the category 5 (Unclassified) according to the Globally Harmonized System, with an LD50 value of over 2000 mg/kg.

Synergism of ochratoxin B and calcium-channel antagonist verapamil caused mitochondrial dysfunction.

We examined the mechanism by which the ochratoxin B induced interaction with calcium-channel antagonist verapamil and mitochondrial dysfunction of the rat trachea in vitro experiment. The tracheas were cut into 2-3 mm wide rings and suspended in a tissue bath. Isometric tension was continuously measured with an isometric force transducer connected to a computer-based data acquisition system. Verapamil (1 × 10(-6) M) produced a concentration-dependent contraction response in rat's tracheal rings pre-contracted by acetylcholine. Incubation of rat's tracheal rings with the ochratoxin B significantly potentiated the contraction responses of verapamil. Verapamil and OTB accelerate the overloading of Ca(2+) in tracheal smooth muscle contributes the tissue toxicity as shown in electron microscopy and mitochondrial enzymes, through a mechanism that could involve perturbations of Ca(2+) homeostasis. These results proved that ochratoxin B is a potential vasoconstrictor mycotoxin with the presence of calcium-channel antagonist. In conclusion, disturbance of Ca(2+) homeostasis caused by OTA and plays a significant role in produces toxicity through mitochondrial enzyme inhibition.

Black fly (Simulium sp) composition, daytime biting activity and possible onchocerciasis infection in north-east, India.

Pupal stages of Simulium were collected and identified from various breeding habitats of twelve locations in northeastern India. Simulium flies, while attempting to land on human were collected between 07:00-17:00 hrs to understand the biting pattern. Seven species belonging to three sub-genera, Eusimulium (1), Gomphostilbia (1) and Simulium (5) belonging genus Simulium were encountered. Out of total seven species recorded, S. (E) aureohirtum, S. (G) tenuistylum and S. (S) rufibasis were predominant and shared 30.3%, 29.9% and 27.6% of total collection. Stream breeding habitat contributed 47.3% of total catch and was found to be preferred breeding habitat (p < 0.0001). S. (S) christophersi and S. (G) tenuistylum were recorded for the first time from the northeastern region of India. Simuliids biting rhythm showed bimodal pattern and were more active during sunny day (p < 0.0001). Microscopic dissection of simuliids (n = 266) did not incriminate simuliids as vector of onchocerciasis.

In Vitro Evaluation of Antagonism of Endophytic Colletotrichum gloeosporioides Against Potent Fungal Pathogens of Camellia sinensis.

An endophytic fungus isolated from Camellia sinensis, Assam, Northeastern India was identified as Colletotrichum gloeosporioides on the basis of morphological characteristics and rDNA ITS analysis. This endophytic fungus was evaluated for growth inhibition against tea pathogens Pestalotiopsis theae and Colletotrichum camelliae. One isolate of C. gloeosporioides showed strong antagonistic activity against Pestalotiopsis theae (64 %) and moderate activity against C. camelliae (37 %). Fifty percent cell-free culture filtrate from 5-day-old cultures showed highest antagonistic activity against both the pathogens although the inhibition percent was less as compared to dual culture. In the experiment of volatile compounds none of the isolates of C. gloeosporioides strains showed visible inhibition against P. theae and C. camelliae. The activity of extracellular hydrolytic enzymes chitinase and protease was also high in this culture fluid and measured 10 and 4.3 IU/µl, respectively.

Monitoring of malaria, Japanese encephalitis and filariasis vectors.

BACKGROUND: Vector monitoring in military stations would help in protecting the armed forces from vector borne diseases such as malaria, Japanese encephalitis and filariasis. METHODS: Adult mosquitoes were collected from four villages around a military station in India using light traps and the species composition was estimated. Insecticide susceptibility of disease vectors against DDT, deltamethrin and permethrin was established using WHO kits. RESULTS: The known malaria vectors constituted 4.9% of the total mosquito collections and Anopheles philippinensis/nivipes (2.05%) was the most abundant. Japanese encephalitis and dengue vectors constituted 25.3 and 0.05% whereas the known vectors of both Japanese encephalitis and filariasis formed 50.9%. The mean (±SEmean) of annual parasitic index, slide positivity and Plasmodium falciparum percentage among the civilian population during the study period were 1.46 ± 0.37, 1.65 ± 0.77 and 50.2 ± 10.7. The filariasis vector Culex quinquefasciatus was resistant to DDT with 65.4% mortality whereas the DDT resistance in the Japanese encephalitis vector Culex vishnui gr. with 91.9% mortality needs to be confirmed. All other species tested were susceptible to DDT, deltamethrin and permethrin. CONCLUSION: Targeted interventions are needed to reduce the disease burden and vector activity in the villages adjoining the military station. The use of insect repellents, bed nets and repellent impregnated uniforms by the troops should be ensured for protection from vector borne diseases.

Evaluation of the genotoxic and antigenotoxic potential of the alkaloid punarnavine from Boerhaavia diffusa.

Boerhaavia diffusa is a traditional herbal medicine extensively used in the Ayurveda and Unani forms of medicine in India and many parts of the world. Different parts of the plant are used as an appetizer, alexiteric, eye tonic, for flushing out the renal system, and to treat blood pressure. This study was conducted to evaluate the in vivo genotoxic and/or antigenotoxic potential of punarnavine, a separated alkaloid from the root of B. diffusa using toxicity studies (OECD guideline 474, 1997). The genotoxic and antigenotoxic potential of punarnavine was assayed using the comet assay on lymphocytes, liver, spleen, brain, and bone marrow as well as using the micronucleus test in bone marrow cells including the in vitro chromosomal aberration test. The results demonstrated that none of the tested doses of punarnavine showed genotoxic effects by the comet assay, or clastogenic effects in the micronucleus test. On the other hand, for all cells evaluated, the three tested doses of punarnavine promoted inhibition of DNA damage induced by cyclophosphamide. Based on these results, we concluded that punarnavine, an alkaloid from the Boerhaavia diffusa root, has no genotoxic or clastogenic effects in our experimental conditions. However, it caused a significant decrease in DNA damage induced by cyclophosphamide. It is suggested that the antigenotoxic properties of this alkaloid may be of great pharmacological importance and beneficial for cancer prevention.

DDT & deltamethrin resistance status of known Japanese encephalitis vectors in Assam, India.

BACKGROUND & OBJECTIVE: Japanese encephalitis (JE) outbreaks are common in Assam, northeastern State of India. Information on resistance in known JE vectors in the affected area is important for effective control measures. This study was undertaken to determine the species abundance of JE vectors endemic to Sibsagar district of Assam, and their susceptibility against DDT and deltamethrin. METHODS: Adult mosquitoes were collected using CDC light trap and aspirators from human dwellings from 13 endemic villages falling under three Primary Health Centres. Collected mosquitoes were identified and unfed female mosquitoes were used for DDT and deltamethrin sensitivity bioassay. The bioassay was performed following WHO protocol using standard susceptibility test kit. Knockdown time (KDT) was monitored at every 10 minutes intervals, whereas mortalities were recorded 24 h post-exposure. Vector density and resistance status were mapped using geographic information system (GIS) technique. RESULTS: A total of 7655 mosquitoes were sampled under three genera, i.e. Anopheles, Culex and Mansonia, and nine species, the JE vector Cx. vishnui group (31.78%) was the most predominant species, followed by Ma. uniformis (16.81%) and Ma. indiana (16.45%). All vector species were suspected to be resistant to DDT and sensitive to deltamethrin, except Ma. indiana, which was suspected to deltamethrin resistant. The KDT50 and KDT95 values of vector mosquitoes for DDT were significantly higher as compared to deltamethrin. The probit model used to estimate KDT50 and KDT95 values did not display normal distribution of percentage knockdown with time for all the vectors tested for DDT and deltamethrin, except for Ma. indiana for deltamethrin assay and Cx. gelidus for the DDT assay. INTERPRETATION & CONCLUSION: Differences in insecticide resistance status were observed between insecticides and vector species. The results of this study provided baseline data on insecticide resistance in known JE vectors of Sibsagar, Assam. The maps generated may allow better communication in control operations and comparison of changes in susceptibility status of these vectors over time.

Acute dermal irritation, sensitization, and acute toxicity studies of a transdermal patch for prophylaxis against ({+/-}) anatoxin-a poisoning.

The skin irritating, sensitizing, and acute dermal toxicity potential of a novel combinational prophylactic transdermal patch, mainly composed of eserine and pralidoxime chloride as active pharmaceutical ingredients, against (±) anatoxin-a poisoning were investigated in rabbits, guinea pigs, and rats in compliance with the Organisation for Economic Cooperation and Development guidelines. In primary skin irritation test, rabbits were dermally attached with the therapeutically active transdermal patch or with a placebo patch for 72 hours. The transdermal patches did not induce any adverse reactions such as erythema and edema on intact skin sites. The active patch was classified as a practically nonirritating material based on the score in the primary irritation index. In the Buehler test, guinea pigs were sensitized by the active or placebo transdermal patches attached for 24 hours. The patches did not induce any sensitization reactions in contrast to a severe sensitization reaction that occurred in the positive control. Therefore, the active patch and placebo patch were both graded as weak in sensitization score and rate. Acute dermal toxicity test in rats did not produce any overt signs of toxicity following a 14-day treatment period. Taken together, these findings suggest that the transdermal patch does not cause skin irritation, skin sensitization, or dermal toxic effects following dermal application.

Nested PCR detection of Plasmodium malariae from microscopy confirmed P. falciparum samples in endemic area of NE India.

The present study evaluates the performance of OptiMAL-IT test and nested PCR assay in detection of malaria parasites. A total of 76 randomly selected blood samples collected from two malaria endemic areas were tested for malaria parasites using microscopy and OptiMAL-IT test in the field. PCR assays were performed in the laboratory using DNA extracted from blood spots of the same samples collected on the FTA classic cards. Of the total of 61 field confirmed malaria positive samples, only 58 (95%) were detected positive using microscopy in the laboratory. Sensitivity, specificity, positive predictive value, negative predictive value and false discovery rate of OptiMal-IT in comparison to the microscopy were 93%, 83%, 95%, 79% and 5%, respectively. On the other hand, the sensitivity and specificity of PCR assay were 97% and 100%, respectively, whereas positive predictive value, negative predictive value and false discovery rate were 100%, 90% and 0%, respectively. The overall performance of OptiMal-IT and PCR assays for malaria diagnosis was 76% and 97%, respectively. PCR assay enabled the identification of infection with Plasmodium malariae Laveran, 1881 in four samples misidentified by microscopy and Plasmodium-specific antigen (PAN) identified by the OptiMAL-IT test. In addition to the standard methods, such PCR assay could be useful to obtain the real incidence of each malaria parasite species for epidemiological perspectives.

Physicochemical characteristics of habitats in relation to the density of container-breeding mosquitoes in Asom, India.

BACKGROUND & OBJECTIVES: Container-breeding mosquitoes, especially Aedes spp are vectors of diseases such as dengue and chikungunya. The abundance of these disease vectors in an area depends on the availability of container habitats and their physicochemical characteristics. The species composition of container-breeding mosquitoes in Asom, India was studied and the larval density was correlated with the habitat characteristics. METHODS: Natural and man-made water-holding containers in Sonitpur district of Asom were surveyed for the presence of mosquito larvae. The percent composition of container-breeding mosquitoes and container index were calculated. The physicochemical characteristics of breeding water such as pH, conductivity, salinity, total dissolved solids, turbidity and dissolved oxygen were measured. RESULTS: Aedes albopictus (93.7%) was the predominant species in the container-breeding habitats whereas Culex quinquefasciatus (2.77%), Armigeres subalbatus (2.26%), Ae. aegypti (0.76%), Toxorhynchites sp (0.4%) and Lutzia sp (0.11%) were recorded in relatively low numbers. The larval density (mean ± SEmean) of the container breeding mosquitoes ranged from 4.4 ± 1.8 to 15.4 ± 8.2, while the container index ranged from 1.58 to 5.68%. The mean (± SEmean) pH, conductivity, salinity, total dissolved solids, turbidity, and dissolved oxygen of water in the container habitats were 7.15 ± 0.11; 396.1 ± 58.5 µS/cm; 0.24 ± 0.04 ppt; 207.1 ± 30.4 mg/l; 32.3 ± 5.1 NTU; and 1.42 ± 0.12% respectively. The mosquito larval density in the container habitats was having significant negative correlation with the conductivity of breeding water (r = - 0.89; p = 0.003). Salinity, total dissolved solids and turbidity of water in the habitats were negatively correlated, whereas pH and dissolved oxygen were positively correlated with the larval density. INTERPRETATION & CONCLUSION: The studies indicated the predominance of Ae. albopictus in the container-breeding habitats and reiterated its importance as a potential vector of dengue and chikungunya in the region. The spread of Ae. aegypti, the principal vector of dengue, in the semi-urban areas probably through road transport is a matter of public health concern. The use of conductivity of breeding water as an index for the proliferation of container breeding mosquitoes in the region could be explored further.