Background & objectives: Dengue fever, caused by dengue virus (DENV), has become a serious threat to human lives. Phytochemicals are known to have great potential to eradicate viral, bacterial and fungal-borne diseases in human beings. This study was aimed at in silico drug development against nonstructural protein 4B (NS4B) of dengue virus 4 (DENV4). Methods: A total of 2750 phytochemicals from different medicinal plants were selected for this study. These plants grow naturally in the climate of Pakistan and India and have been used for the treatment of various pathologies in human for long-time. The ADMET studies, molecular docking and density functional theory (DFT) based analysis were carried out to determine the potential inhibitory properties of these phytochemicals. Results: The ADMET analysis and docking results revealed nine phytochemicals, i.e. Silymarin, Flavobion, Derrisin, Isosilybin, Mundulinol, Silydianin, Isopomiferin, Narlumicine and Oxysanguinarine to have potential inhibitory properties against DENV and can be considered for additional in vitro and in vivo studies to assess their inhibitory effects against DENV replication. They exhibited binding affinity ≥−8 kcal/mol against DENV4-NS4B. Furthermore, DFT based analysis revealed high reactivity for these nine phytochemicals in the binding pocket of DENV4-NS4B, based on E_LUMO, E_HOMO and band energy gap. Interpretation & conclusion: Five out of nine phytochemicals are reported for the first time as novel DENV inhibitors. These included three phytochemicals from Silybum marianum, i.e. Derrisin, Mundulinol, Isopomiferin, and two phytochemicals from Fumaria indica, i.e. Narlumicine and Oxysanguinarine. However, all the nine phytochemicals can be considered for in vitro and in vivo analysis for the development of potential DENV inhibitors.

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Malaria, caused by the protozoan parasites of the genus Plasmodium, is a major health problem in many countries of the world. Five parasite species namely, Plasmodium falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi, cause malaria in humans. Of these, P. falciparum and P. vivax are the most prevalent and account for the majority of the global malaria cases. In most areas of Africa, P. vivax infection is essentially absent because of the inherited lack of Duffy antigen receptor for chemokines on the surface of red blood cells that is involved in the parasite invasion of erythrocytes. Therefore, in Africa, most malaria infections are by P. falciparum and the highest burden of P. vivax infection is in Southeast Asia and South America. Plasmodium falciparum is the most virulent and as such, it is responsible for the majority of malarial mortality, particularly in Africa. Although, P. vivax infection has long been considered to be benign, recent studies have reported life-threatening consequences, including acute respiratory distress syndrome, cerebral malaria, multi-organ failure, dyserythropoiesis and anaemia. Despite exhibiting low parasite biomass in infected people due to parasite’s specificity to infect only reticulocytes, P. vivax infection triggers higher inflammatory responses and exacerbated clinical symptoms than P. falciparum, such as fever and chills. Another characteristic feature of P. vivax infection, compared to P. falciparum infection, is persistence of the parasite as dormant liver-stage hypnozoites, causing recurrent episodes of malaria. This review article summarizes the published information on P. vivax epidemiology, drug resistance and pathophysiology.

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The World Malaria Report 2018 published by the World Health Organization highlights that no significant progress in reducing global malaria cases was achieved for the period 2015–2017. India carries 4% of the global malaria burden and contributes 87% of the total malaria cases in South-East Asia. India is in malaria elimination mode, and set targets for malaria-free status by 2030. Diagnosis and treatment of asymptomatic falciparum malaria cases continues to be a challenge for health care providers. To overcome these hurdles innovative solutions along with the existing tools and strategies involving vector control, mass drug administration, disease surveillance hold the key to solve this gigantic health problem.

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Visceral leishmaniasis (VL) is an important parasitic disease which is endemic in different parts of Iran; and domestic and wild canines are principal reservoir hosts of the disease. The objective of this study was to review the spatial distribution of canine VL (CVL) caused by Leishmania infantum in domestic and wild canines in different geographical areas of Iran. An extensive literature search was conducted in different international and national databases, including Cochrane, MEDLINE/PubMed, Scopus, Web of Science and Iran Medex to find articles with the words “visceral leishmaniasis in Iran” in their titles and “canine visceral leishmaniasis in Iran” or “feline visceral leishmaniasis in Iran” or “accidental reservoir hosts of visceral leishmaniasis in Iran” in their subtitles, irrespective of the type and duration of study. Screening of the irrelevant articles from total 36,342, yielded 61 eligible articles. More than 93% of the studies were carried out on domestic dogs (Canis familiaris, n = 57) and the remaining were on other carnivores such as wild canines including foxes (Vulpes vulpes, n = 4), jackals (C. aureus, n = 6) and wolves (C. lupus, n = 6); while studies on domestic cats (Felis catus, n = 3) as well as desert rodents (n = 2) were rare. The average rate of L. infantum infections reported among domestic dogs using direct agglutination test (DAT) in Iran was 12.5%. The highest prevalence rate (14%) was reported from the northwest regions of the country where VL is endemic. The review indicates that CVL is endemic in various parts of Iran and domestic dogs are the main and potential reservoir hosts of the disease. Other carnivores, such as domestic cats and some species of desert rodents (Cricetulus migratorius, Mesocricetus auratus and Meriones persicus) seem to be playing a role in the maintenance of transmission cycle of L. infantum in the endemic areas of the disease.

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Background & objectives: Increase in prevalence and intensity of insecticide-resistance in vectors of vector-borne diseases is a major threat to sustainable disease control; and, for their effective management, studies on resistance mechanisms are important to come out with suitable strategies. Esterases are major class of detoxification enzymes in mosquitoes, which confers protection against insecticides in causing resistance. This study was aimed at biochemical characterization of esterases responsible for malathion resistance in Anopheles stephensi mosquitoes, along with its validation through biochemical techniques and native-PAGE assays. Methods: Laboratory maintained susceptible and resistant An. stephensi mosquitoes were used for assessing the activity and effect of α- and β-esterases on malathion. Bioassay, synergist bioassay, biochemical assay and native- PAGE were employed to characterize the role of esterases in conferring malathion-resistance. Results: Notably significant (p < 0.0001) enhancement in α- and β-esterases activity was observed with 2-fold increase in resistant An. stephensi_GOA compared to susceptible An. stephensi_BB native-PAGE depicted two major bands ‘a’ (R_f = 0.80) and ‘b’ (R_f = 0.72) in susceptible An. stephensi_BB while one intense band ‘b’ (R_f = 0.72) was visible in resistant An. stephensi_GOA. Inhibition assay revealed complete inhibition of α- and β-esterases activity in presence of 1 mM malathion in susceptible strain compared to observed partial inhibition in resistant strain on native-PAGE. Interpretation & conclusion: This study provides a better understanding on the role of esterase enzyme (carboxylesterase) in conferring malathion-resistance in An. stephensi mosquitoes, as evident from the native-PAGE assay results. The study results could be used in characterizing the resistance mechanisms in vectors and for suggesting alternative chemical insecticide based resistance management strategies for effective vector-borne disease control.

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Background & objectives: Rift Valley fever (RVF) is a zoonotic vector-borne disease that primarily affects domestic animals but can also infect humans. The purpose of the present study was to investigate the presence of antibodies against RVF virus (RVFV) in ruminants, viz. cattle, sheep, and goats in Kurdistan Province of western Iran. Methods: Blood samples were collected from 288 ruminants (118 cattle, 142 sheep and 28 goats) of both sexes, under age groups ≤1, 1–3, 3–5 and ≥5 yr, from January 2016 to December 2016. Clinical symptoms and history of abortion were recorded. The presence of RVFV-specific antibodies was investigated by using ELISA (competitive) and indirect immunofluorescence assay (IIFA) after separation of serum. Results: The results of two tests were positive for five (1.74%) of total 288 animals which included two cattle of 118 (1.7%), and three sheep of 142 (2.11%). The results of IIFA were correlated with the ELISA results. All animals were clinically normal. No significant relationship between the RVFV infection rate and the variable considered, i.e. season, animal’s age or sex, and the species of the animal (p ≥ 0.05), although there were four seropositive animals in the age group 1–3 and five seropositive animals in the spring season. Interpretation & conclusion: The results of the study revealed the presence of low-level RVFV circulation among the ruminants of Kurdistan Province in Iran indicating that they are at risk of exposure to the virus during their lifetime. Since the present study was the first serological study on RVF in Iran with positive results, further studies are suggested including other areas of Iran.

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Aedes vittatus (Bigot) mosquito is a voracious biter of humans and has a geographical distribution throughout tropical Asia, Africa and the Mediterranean region of Europe. It is predominantly a rock-hole breeder, though it can breed in diverse macro- and micro-habitats. The mosquito plays an important role in the maintenance and transmission of yellow fever (YFV), dengue (DENV), chikungunya (CHIKV) and Zika (ZIKV) viruses. It has been implicated as an important vector of YFV in several African countries as evidenced by repeated virus isolations from the mosquito and its potential to transmit the virus experimentally. Similarly, DENV-2 has been isolated from wild caught Ae. vittatus mosquitoes in Senegal, Africa which has been shown to circulate the virus in sylvatic populations without causing human infection. Experimental studies have shown replication of the virus at a low scale in naturally infected mosquitoes while high rate of infection and dissemination have been reported in parenterally infected mosquitoes. Natural isolation of ZIKV has been reported from Senegal and Cote d’Ivoire from these mosquitoes. They were found highly competent to transmit the virus experimentally and the transmission rate is at par with Ae. leuteocephalus, the primary vector of ZIKV. A few CHIKV isolations have also been reported from the mosquitoes in Senegal and other countries in Africa. Experimental studies have demonstrated high susceptibility, early dissemination and efficient transmission of CHIKV by Ae. vittatus mosquitoes. The mosquitoes with their high susceptibility and competence to transmit important viruses, viz. YFV, DENV, CHIKV and ZIKV pose a major threat to public health due to their abundance and anthropophilic behaviour.

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Background & objectives: Crimean-Congo haemorrhagic fever virus (CCHFV) causes severe disease with fatality rate of 30%. The virus is transmitted to humans through the bite of an infected tick, direct contact with the products of infected livestock as well as nosocomially. The disease occurs sporadically throughout many of African, Asian and European countries. Different species of ticks serve either as vector or reservoir for CCHFV. This study was aimed to determine the prevalence of CCHFV in hard ticks (Ixodidae) in the Golestan Province of Iran. Methods: A molecular survey was conducted on hard ticks (Ixodidae) isolated from six counties in Golestan Province, north of Iran during 2014–15. The ticks were identified using morphological characteristics and presence of CCHFV RNA was detected using RT-PCR. Results: Data revealed the presence of CCHFV in 5.3% of the ticks selected for screening. The infected ticks belonged to Hyalomma dromedarii, Hy. anatolicum, Hy. marginatum and Rhipicephalus sanguineus species. Interpretation & conclusion: The study demonstrated that Hyalomma ticks are the main vectors of CCHFV in Golestan Province. Thus, preventive strategies such as using acaricides and repellents in order to avoid contact with Hyalomma ticks are proposed.

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Background & objectives: Scrub typhus is as an emerging infectious disease that generally causes acute febrile illness, with disease spectrum ranging from mild illness to multiorgan dysfunction. This study was aimed to report the clinical profile, complications and risk factors associated with severe illness in patients with scrub typhus, outside the intensive care setting. Methods: It was a prospective study, which involved recruitment of patients with acute febrile illness and diagnosed to have scrub typhus, who were admitted to the general medical wards of a tertiary care centre in Kanchipuram district, in semi-urban south India, over a 12 month period between June 2015 and May 2016. The diagnosis was established both clinically (with or without pathognomonic eschar) and by a positive test of IgM antibodies against scrub typhus by ELISA. The severity of scrub typhus was determined by the presence of organ dysfunction, and the factors associated with it were analyzed. Results: A total of 50 patients with mean age of 39.6±20.5 yr (mean ± SD) were admitted. The mean duration of illness before presentation was 9.10 ± 8.6 days. The mean duration of hospital stay was 7.7±3.6 days. The symptoms included fever, abdominal symptoms, headache, dysuria, breathlessness and altered sensorium. Most common findings on physical examination were eschar (58%), crepitations in the chest (36%), hepatomegaly (34%) and lymphadenopathy (30%). Thirty two percent had respiratory complications, 4% required mechanical ventilation, 24% had shock, 16% had acute kidney injury, and 6% had dysfunction of ≥2 organs. Age of >50 yr, longer duration of illness (>7 days), residence in a rural area and the absence of eschar were found to be independent risk factors for development of severe illness. Interpretation & conclusion: Severe scrub typhus infection among non-ICU patients is more likely to occur in elderly patients and in those with longer duration of illness prior to presentation. The subset of patients without eschar might be more prone to develop complications.

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Though asymptomatic plasmodial infection (API) is well known phenomenon and play an important role in different populations and malaria transmission settings, it has received less attention in malaria intervention strategies. This review was aimed to estimate the prevalence of API in pregnant women across the world. The bibliography records relevant to the study were searched on PubMed and Lilacs, till August 15, 2016, without restriction of language. A total of 78 references were identified, of which 29 met the inclusion criteria. The study of the identified reports revealed that the mean prevalence of API in pregnant women was 10.8% (3382/31186), with wide variation among countries and transmission settings. The reports showed that APIs are very common even in low malaria transmission areas, and most of the APIs are due to submicroscopic plasmodial infection (SPI). More sensitive diagnostic tools are required to address API and SPI in such areas. Every malaria endemic region/country should carry out systematic studies for accurate estimation of frequency for both these events (API and SPI) in different populations for planning appropriate intervention measures.

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Background & objectives: An increase in Zika virus (ZIKV) epidemic during the last decade has become a major global concern as the virus affects both newborns and adult humans. Earlier studies have shown the impact of ZIKV infection in developing human foetus. However, effective in vitro model of target cells for studying the ZIKV infection in adult human neurons is not available. This study aimed to establish the use of human neuroblastoma cell line (SH-SY5Y) for studying an infection of ZIKV in vitro. Methods: ZIKV growth kinetics, viral toxicity, and SH-SY5Y cell vialibity were determined after ZIKV infection in SH-SY5Y cells in vitro. ZIKV-infected SH-SY5Y cells were morphologically analysed and compared with nonhuman primate Vero cells. Furthermore, the susceptibility of SH-SY5Y cells to ZIKV infection was also determined. Results: The results showed that ZIKV efficiently infects SH-SY5Y cell lines in vitro. Gradual changes of several cellular homeostasis parameters including cell viability, cytotoxicity, and cell morphology were observed in ZIKV-infected SH-SY5Y cells when compared to mock-treated or non-human primate cells. Interestingly, ZIKV particles were detected in the nucleoplasmic compartment of the infected SH-SY5Y cells. Interpretation & conclusion: The results suggest that ZIKV particle can be detected in the nucleoplasmic compartment of the infected SH-SY5Y cells beside the known viral replicating cytoplasmic area. Hence, SH-SY5Y cells can be used as an in vitro adult human neuronal cell-based model, for further elucidating the ZIKV biology, and highlight other possible significance of Zika virus distribution through nuclear localization, which may correlate to the neuropathological defects in ZIKV-infected adult humans.

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Background & objectives: It is imperative to know the aetiology of acute encephalitis syndrome (AES) for patient management and policy making. The present study was carried out to determine the prevalence of common aetiological agents of AES in Uttar Pradesh (UP) state of India. Methods: Serum and/or CSF samples were collected from AES patients admitted at Gandhi Memorial and Associated Hospital, King George's Medical University, Lucknow, a tertiary care centre, UP during 2014–16. Cerebrospinal fluid (CSF) and serum samples from cases were tested for IgM antibodies against Japanese encephalitis virus (anti-JEV), and dengue virus (anti-DENV) by ELISA; and for enterovirus, herpes simplex virus (HSV) and varicella zoster virus (VZV) by real-time PCR. Serum samples of cases having sufficient CSF volume, were also tested for anti-scrub typhus IgM antibodies and for Neisseria meningitides, Streptococcus pneumoniae and Haemophilus influenzae. Results: JEV and DENV (8% each) were the most common identified aetiology from the 4092 enrolled patients. Enterovirus, HSV and VZV, each were detected in <1% AES cases. Co-positivity occurred in 48 cases. Scrub typhus (31.8%) was the most common aetiology detected. Haemophilus influenzae and S. pneumoniae were detected in 0.97 and 0.94% cases, respectively, however, N. meningitides was not detected in any of the cases. About 40% of the JEV/DENV positive AES cases were adults. The gap between the total number of AES cases and those with JEV/ DENV infection increased during monsoon and post-monsoon seasons. Interpretation & conclusion: Scrub typhus, JEV and DENV are the main aetiological agents of AES in UP. DENV and JEV can no longer be considered paediatric diseases. The prevalence of non-JEV/DENV aetiology of AES increases in the monsoon and post-monsoon seasons.

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Background & objectives: Assam is the most vulnerable state for Japanese encephalitis (JE) in India. The situation warrants characterization of epidemiological patterns of JE in vectors, pigs and human population. This investigation was aimed to determine the relative abundance of mosquito species and seroprevalence of JE in pigs in order to draw an epidemiological association with reported human JE cases in Assam. Methods: Pig sera and mosquitoes from selected farms in Sivasagar and Kamrup districts of Assam were collected fortnightly for one year during June 2015–May 2016. Pig sera were tested for JE antibodies by haemagglutination and virus neurtralization tests. Mosquito species were identified microscopically following the taxonomic keys. The results were analyzed with data on confirmed human JE cases in the selected districts. Results: Culex gelidus (26.07%) and Cx. tritaeniorhynchus (24.07%) were the most abundant species in collected mosquitoes (n = 997). A total of 22.99% of pigs (n = 335) were JEV seropositive and 45.65% of human acute encephalitis syndrome cases (n = 230) were positive for JE virus (JEV) infection. Relative mosquito abundance, pig positivity and human cases were highest during monsoon (June–September) and least during winter (December–February). Rise in mosquito population was observed during pre-monsoon season (March–May) and concurrently higher number of human cases and pig seropositivity were recorded. A good correlation was observed between mosquito number and JEV positivity in pigs/human, and between pigs and human cases (p < 0.05). Human population in Sivasagar was at higher risk for JE infection (OR: 6.46, p < 0.0001) than in Kamrup rural district. Interpretation & conclusion: This study indicates that a seasonal correlation exists between mosquito abundance and JEV seroconversion in pigs with concurrent human JEV outbreaks under field conditions in Sivasagar and Kamrup rural districts of Assam and that monitoring mosquito abundance/density and pig JEV seropositivity may help in predicting JEV outbreak in human population in the region.

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Background & objectives: Zoonotic cutaneous leishmaniasis (ZCL) is among the most endemic zoonotic diseases in Golestan Province of Iran. The aim of this study was to find the high risk areas of this infection by considering the distribution of reservoirs and human infection. Methods: A cross-sectional study was conducted, in which Rhombomys opimus (Gerbils) were captured from different collection sites across the Golestan Province, Iran. records about the occurrence of Rh. opimus in the Province was obtained from earlier studies and were gathered in a database. Furthermore, records about the disease existence were also obtained from the health system database of Golestan Province. Villages with at least three cases of ZcL were considered endemic foci and used as presence sites for Leishmania major. ArcGIS and MaxEnt model were used to map and predict the best ecological niches for both reservoir and parasite. Results: According to the MaxEnt model, the area under Roc curve for Rh. opimus and L. major was 0.92 and 0.89, respectively. The probability of presence for both species in the northeastern part of Golestan Province was more than the other parts. The Jackknife test indicated that factors like temperature and altitude plays significant role in predicting the environmental suitability for ZcL reservoir and parasite, respectively. Interpretation & conclusion: this modeling approach predicted the areas suitable for reservoir host and circulation of parasite to human. These findings can be used in proper mapping, surveillance and control of the CL.

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Background & objectives: Trypanosoma cruzi and Leishmania spp. are protozoans that cause American trypanosomiasis and leishmaniasis, respectively. In endemic foci where both diseases coincide, coinfection can occur. The objective of this work was the characterization of the parasites involved in coinfection in several endemic areas of Venezuela. Methods: Molecular characterization was done in 30 samples of several species of mammals (Didelphis marsupialis, Equus mulus, Rattus rattus, Canis familiaris, Felis catus, and Sciurus granatensis) from the states of Anzoategui, Cojedes and Capital District diagnosed with T. cruzi and Leishmania spp. coinfections. For the typing of T. cruzi DTUs, the markers of miniexon, 24Sa rDNA, 18Sa rDNA, and hsp60-PCR-RFLP (EcoRV) were used. Infection by Leishmania spp. was characterized by miniexon multiplex PCR for complexes of Leishmania and ITS1-PCR-RFLP (HaeIII, HhaI, and RsaI) for the identification of the species. Results: The T. cruzi TcI was present in 100% of the coinfected mammals, which included 76.7% of triple infection by T. cruzi TcI-complex–L. (L) mexicana–L. infantum/chagasi, 13.3% of double infection by T. cruzi TcI-L. mexicana and 10% of double infection by T. cruzi Tcl—L. infantum/chagasi. Interpretation & conclusion: These results suggest that the double or triple infection is a phenomenon existing in almost all the coendemics areas and mammals studied, which might influence the mechanisms of adaptation and pathogenicity of these parasites.

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Mosquito-borne diseases are spreading at an alarming rate. Globally millions of deaths occur due to the diseases transmitted by mosquitoes, next to AIDS and tuberculosis. Several methods have been used to control these vectors and the diseases caused by them. Earlier studies have shown the potential role of mosquito gut inhabitants on disease transmission. Their findings can be used as an innovative approach for devising strategies to modify the survival of mosquitoes by reducing their lifespan, reproduction and disease transmission abilities. In this study, microbiome of the three genera of mosquitoes, namely Aedes, Anopheles, and Culex along with their vectorial capacity have been reviewed for assessing their role in mosquito control and transmission. Relevant articles were accessed using different databases, including LILACS, Embase, Science Direct and PubMed from inception to June 2017. The search keywords included “Aedes”, “Anopheles”, “Culex”, “gut inhabitants”, “vectors”, and “mosquito”. The titles, abstract, and keywords of the retrieved articles were screened, and eligible research articles were sorted. The review indicates that paratransgenesis may be considered as a versatile and effective strategy to eradicate the spurt of mosquito transmitting diseases. Enterobacter species is the most common type of gram-negative bacteria associated with the gut of all the three genera of mosquitoes. It was found to have a beneficial effect on humans as it helps in destroying dreadful disease-transmitting vectors. These symbiotic qualities of the microbes need to be thoroughly investigated further to reveal their antipathogenic effect on the vector.

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Background & objectives: Aedes aegypti and Ae. albopictus are major arboviral vectors that are considered to lay eggs, and undergo preimaginal development only in fresh water collections. However, recently they have been also shown to develop in coastal brackish water habitats. The ability of the biologically variant salinity-tolerant Aedes vectors to transmit arboviral diseases is unknown. We therefore, investigated the infection of salinity-tolerant Aedes mosquitoes with dengue virus (DENV) and analysed dengue incidence and rainfall data to assess the contribution of salinity-tolerant Aedes vectors to dengue transmission in the coastal Jaffna peninsula in Sri Lanka. Methods: Brackish and fresh water developing female Ae. aegypti and Ae. albopictus were tested for their ability to become infected with DENV through in vitro blood feeding and then transmit DENV vertically to their progeny. An immunochromatographic test for the NS1 antigen was used to detect DENV. Temporal variation in dengue incidence in relation to rainfall was analysed for the peninsula and other parts of Sri Lanka. Results: Aedes aegypti and Ae. albopictus developing in brackish water, became infected with DENV through in vitro blood feeding and the infected mosquitoes were able to vertically transmit DENV to their progeny. Monsoonal rainfall was the discernible factor responsible for the seasonal increase in dengue incidence in the peninsula and elsewhere in Sri Lanka. Interpretation & conclusion: Fresh water Aedes vectors are main contributors to the increased dengue incidence that typically follows monsoons in the Jaffna peninsula and elsewhere in Sri Lanka. It is possible however, that brackish water-developing Aedes constitute a perennial reservoir for DENV to maintain a basal level of dengue transmission in coastal areas of the peninsula during the dry season, and this supports increased transmission when monsoonal rains expand populations of fresh water Aedes.

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Background & objectives: Leishmaniasis is one of the major neglected zoonotic parasitic diseases whose treatment and control is very complex. Pentavalent antimonials remain the primary drugs against different forms of leishmaniasis, however, resistance to antimony and its toxic effects has necessitated the development of alternative medications such as use of medicinal plants and natural compounds. The aim of the current study was to assess the in vitro and in vivo activities of chitosan as a natural resource against Leishmania major. Methods: Low molecular weight chitosan, with 95% degree of deacetylation was melted in normal saline to a final concentration of 50, 100, 200 and 400 μg/ml. Then, the promastigotes of L. major (Iranian strain) were added to the wells of 96-well plate and 20 μl of each concentration was added to the RPMI 1640 medium. Live and dead promastigotes were counted after adding 0.1% eosin stain. The efficacy of the chitosan was also examined in BALB/c mice infected with Iranian strain of L. major. All in vitro experiments were performed in triplicate and the results of in vitro and in vivo tests were compared to the acetic acid and NaOH as negative control and glucantime as positive control. Results: The low molecular weight chitosan was completely effective at concentrations of 100, 200 and 400 μg/ml on promastigotes of L. major after 180 min of application. Moreover, in the in vivo study, the mean size of dermal lesions significantly decreased in the groups treated with the chitosan compared to the control group. Interpretation & conclusion: According to the results of the study, it can be concluded that chitosan is a potent active compound against L. major and could be evaluated as a new antileishmanial drug in the future.

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Background & objectives: The transmission of schistosomiasis, caused by trematodes of the genus Schistosoma, relies on freshwater snails that act as an intermediate host while human and other mammalian act as the definitive hosts. Many non-human primates (NHPs) such as Chlorocebus aethiops (vervet) and Papio anubis (baboon) are reported to be infected with Schistosoma mansoni in Ethiopia, but the role they play in parasite maintenance and transmission is still not clear. The objective of this study was, therefore, to determine the prevalence of S. mansoni infection in human and NHPs living in close proximities to villages in selected endemic areas of Ethiopia. Methods: In this cross-sectional study, stool specimens were collected from 911 humans, and fresh faecal droppings from 106 NHPs from Bochesa (Ziway), Bishan Gari (Kime) and Finchaa (Camp 7) endemic localities in Oromia Regional State, and examined for S. mansoni and other helminth infections using Kato-Katz method for human participants and direct microscopic examination for NHPs. Results: The prevalence of helminthiasis among the human study population was 42.4% (386/911), and for soil-transmitted helminth infections (A. lumbricoides, hookworms, and T. trichiura) it was 13.4% (122/911). In humans S. mansoni was the predominant parasite, 23.1% (210/911) followed by A. lumbricoides, 8.7% (79/911); hookworms, 5.8% (53/911); T. trichiura, 4.8% (44/911); Taenia species, 2.2% (20/911); E. vermicularis, 2.1% (19/911); and H. nana, 3.2% (29/911). NHPs were found positive for Trichuris species and Strongyloides species besides S. mansoni. Interpretation & conclusion: NHPs might play a significant role in local transmission and maintenance of S. mansoni infection even in the absence of human hosts. This calls for supplementation of chemotherapy for schistosomiasis along with measures such as snail control to interrupt transmission of the disease from humans to NHPs, and vice-versa.

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Background & objectives: Phlebotomine sandflies (Diptera: Psychodidae) transmit several important zoonotic diseases to humans and leishmaniasis is one of them. Two types of leishmaniasis, viz. visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) are endemic in Iran. The main vector of anthroponotic cutaneous leishmaniasis (ACL) is Phlebotomus sergenti. The aim of the present study was to determine the susceptibility status of wild strain of P. sergenti to different imagicides of DDT, bendiocarb and permethrin at the median lethal time, LT₅₀ level. Methods: Sandflies were collected from selected village in North Khorasan Province, northeast of Iran from indoors using CDC light-traps. Susceptibility test was carried out against DDT (4%), bendiocarb (0.1%) and permethrin (0.75%) for all the females according to WHO method, and mortality was calculated. Species identification was carried out using the morphological keys. Data were analysed using probit regression analysis to determine the LT₅₀ and LT₉₀ values. Results: In total, 851 female P. sergenti sandflies were tested. LT₅₀ values to DDT (4%), Bendiocarb (0.1%) and permethrin (0.75%) were 15.4, 19.2 and 6.3 min respectively. The values for LT₉₀ were 51.1, 47.4 and 18.6 min respectively. The mortality rates for 1 h exposure time to DDT, bendiocarb and permethrin were 89.8 ± 1.4; 93.6 ± 1.4; and 95.6 ± 1.7%, respectively. Interpretation & conclusion: The suscesptibility studies revealed development of resistance against DDT (4%) in the wild strain of P. sergenti population. Monitoring and mapping of insecticide resistance in the region is recommended for vector control.

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Background & objectives: Rickettsial diseases are important re-emerging infections that mostly go unnoticed or are misdiagnosed. Though few case reports of Indian tick typhus have been reported in Indian literature in the past 10 yr, prevalence surveys are few and far between. The objective of this research was to study the seroprevalence of spotted fever (SF) group rickettsiosis and its coinfection with scrub typhus (ST) in Puducherry region of south India, as these two diseases may show similar clinical presentations. Methods: During 2012–2015, paired sera of 320 febrile patients were examined for Rickettsia conorii IgM/IgG by ELISA and OX19 and OX2 agglutinins by Weil-Felix test. Additionally, patients were screened for ST IgM ELISA. Statistical analysis was performed for clinical and laboratory parameters in children and adults using Fisher’s exact test and chi-square test with Yates correction. Results: Out of 320 patients, 142 (44.38%) had R. conorii IgM and/or IgG antibodies. Only IgM was present in 72 (22.5%) patients, while 36 patients were positive for IgG only and 34 were positive for both IgG and IgM. A total of 68 patients (21.25%) showed only OX19 and/or OX2 antibodies (titres ≥ 1 : 80). SF and ST coinfection was observed in 47 cases (14.69%). Interpretation & conclusion: Seroprevalence of SF in Puducherry was found to be quite high (44.38%). ST and SF coinfection was observed in 34.50% of the SG IgG positive patients, however, this require further evaluation by PCR to rule out cross-reaction or false positivity. At present ELISA seems to be an affordable alternative to highly subjective and technically demanding immunofluorescence assay (IFA) for serodiagnosis of SF.

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Background & objectives : Schistosomiasis is a rural endemic disease that has been expanding to urban and coastal areas in the state of Pernambuco, Brazil. The aim of this study was to characterize the distribution of breeding sites of the causative vector, Biomphalaria straminea in an endemic municipality for schistosomiasis and to present the predictive models for occurrences and dispersal of this vector snail to new areas. Methods : A malacological survey was conducted during January to December 2015 in the municipality of São Lourenço da Mata, Pernambuco, Brazil to identify the breeding sites of Biomphalaria. Faecal contamination was determined by means of the Colitag™ diagnostic kit. Rainfall data were collected, and correlated with snail distribution data. Kernel density estimation, kriging and maximum entropy (MaxEnt) modeling were used for spatial data analysis, by means of the spatial analysis software packages. Results : Out of the 130 demarcated collection points, 64 were classified as breeding sites for B. straminea. A total of 5,250 snails were collected from these sites. Among these 64 sites, four were considered as foci of schistosomiasis transmission and 54 as potential transmission foci. An inverse relationship between rainfall and snail density was observed. Kernel spatial analysis identified three areas at higher risk of snail occurrence, which were also the areas of highest faecal contamination and included two transmission foci. Kriging and MaxEnt modeling simulated the scenarios obtained through the kernel analyses. Interpretation & conclusion : Use of geostatistical tools (Kriging and MaxEnt) is efficient for identifying areas at risk and for estimating the dispersal of Biomphalaria species across the study area. Occurrence of B. straminea in the study area is influenced by the rainy season, as it becomes more abundant during the period immediately after the rainy season, increasing the risk of dispersal and the appearance of new transmission foci.

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Background & objectives: Vector control strategies play significant role in reducing the transmission of malaria, dengue and other vector-borne diseases. The control of vector population using synthetic insecticides has resulted in development of insecticide resistance and negative effects on humans and environment. The present investigation evaluated the larvicidal potential of methanol, dichloromethane and hexane extracts of leaves and seeds of Ricinus communis (castor) plant against the early IV instar larvae of the dengue vector, Aedes aegypti, and malaria vector, Anopheles culicifacies. Methods: Plant extracts were screened for their efficacy against Ae. aegypti and An. culicifacies using WHO standard larval susceptibility test method. Dose response bioassay was performed to get lethal concentrations. Further, gas chromatography-mass spectroscopy (GC-MS) analysis was carried out to identify the bioactive chemical constituents of the extracts of R. communis. Toxicity of the extracts towards non-target organism, Poecilia reticulata was also evaluated. Results: The leaf and seed extracts of R. communis showed significant mortality against the larvae of Ae. aegypti and An. culicifacies at concentrations of 31.25, 62.5, 125, 250, 500 ppm; and 2, 4, 8, 16, 32, 64 ppm, respectively. At 24 h of the exposure period, the larvicidal activities were highest for the methanol extract of seeds with LC₅₀ 15.52 and 9.37 ppm and LC₉₀ 45.24 and 31.1 ppm for Ae. aegypti and An. culicifacies, respectively. The methanol extract of seeds and leaves was found to be safe towards non-target organism, P. reticulata. The GC-MS profile showed that seed extracts were having higher concentration of stigmasterol (7.5%), β-sitosterol (11.48%), methyl linoleate (2.5%), vitamin E (11.93%), and ricinoleic acid (34%) than the leaf extracts. Interpretation & conclusion: The seed extract of R. communis has better larvicidal activity than the leaf extract and can be used as an effective larvicide against mosquitoes. The non-toxicity of the extracts towards P. reticulata further suggests that these plant extracts could be used along with predatory fishes in integrated vector control approaches.

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Background & objectives: Dengue fever (DF) is a common cause of acute febrile illness. Skin involvement is seen in more than half of the patients. This study was aimed to compare the clinical profile and outcome in DF patients with or without skin involvement. Methods: This study included all the patients with DF from the acute febrile illness database of a tertiary care health centre in south India. These patients were further subgrouped into SP and SN (skin involvement positive and negative) based on the presence and absence of skin rash. Differences in clinical presentation, laboratory parameters, disease course, morbidity and outcome among patients with DF with or without skin rash were recorded and analysed statistically. Results: In total 387 patients (>16 yr) with DF were enrolled into the study. Among these 55 patients had evidence of skin rash. Presence of history of overt bleeding (OR = 4.96, p = 0.027) including gum bleeding (OR = 1.17, p = 0.23), epistaxis (OR = 5.52, p = 0.04), and haematuria (OR = 6.41, p = 0.01) were more among patients with SP as compared to SN. The SP patients were found to have lower levels of platelets during the disease course. Patients with SP had a higher percentage of platelet transfusion which was statistically significant. There was no difference in organ dysfunction and mortality among both the groups. Interpretation & conclusion: Cutaneous involvement, though common, is not pathognomonic and can help in dengue diagnosis. Adult patients with skin rash can develop worsening thrombocytopenia requiring platelet transfusion. However, there are limited data to suggest that such patients have a worse outcome and higher mortality.

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