Background & objectives: Rodents are important reservoir hosts for several zoonotic pathogens such as Rickettsia, Leptospira and Bartonella. Studies on the prevalence of zoonotic pathogens in Vietnam are data deficient, and there is a scarcity of data on multiple co-infections of zoonotic pathogens to date. This study examined the prevalence of Rickettsia spp., Leptospira spp., and Bartonella spp. and the co-infection of these pathogens in rodents captured in three provinces of northern Vietnam - Ha Giang, Lao Cai and Cao Bang. Methods: In total, 133 rodents of 25 species were screened for pathogen prevalence by real-time PCR. Results: Very high infection rates were found for each pathogen, with 42 of 133 rodents (31.6%) positive for Bartonella and 33 of 133 (24.8%) positive for Rickettsia (5.3% were positive for Rickettsia typhi, and 19.5% were infected with Rickettsia spotted fever group). Additionally, 24 rodents (18%) were positive for Leptospira. Double infection among these three pathogens was found in 26 of 133 rodents (18.8%), with the highest dual infection rates for Rickettsia and Bartonella co-infection (40%) and Leptospira and Bartonella co-infection (up to 40%), followed by Rickettsia and Leptospira co-infection (20% of animals investigated). One case of triple infection was documented for a house rat (Rattus cf. rattus species group) trapped in Ha Giang province. Interpretation & conclusion: Our survey indicates that rodents in northern Vietnam may host multiple zoonotic pathogens simultaneously; thus, rodents contribute significantly to the increased risk of transmission of multiple zoonotic infections from animals to humans.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub] [CITATIONS]  [PubMed]

Background & objectives: Anopheles stephensi is an important vector of malaria in South East Asia. The abundance and diversity of gut microbiota in the disease vectors affect their development, digestion, metabolism and immunity. The immatures of An. stephensi engulf microbes from their aquatic environment. The present study investigates midgut microbiota of wild and laboratory populations and compares it with their habitat bacterial diversity to study transstadial transmissibility. Methods: The gut microbes from immatures, adults and water samples were cultured at ambient conditions on different media. The colony and biochemical characteristics, and 16S rRNA gene sequencing of gut microbes were studied. Results: Altogether, 298 bacterial isolates were characterized as 21 genera belonging to four major Phyla viz., Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. In the field population-1, Proteobacteria and Firmicutes accounted for 49% and Actinobacteria constituted 51% of the bacterial isolates. In field population-2, Bacteroidetes and Firmicutes accounted for 99% of the isolates. In the laboratory populations, Firmicutes constituted 77%, while Proteobacteria 23% of the isolates. Additionally, 9 genera occurred in the breeding habitats, 13 in the larval midgut, 6 in pupal midgut, 9 in male midgut and 10 in the female midgut. Interpretation & conclusion: This is a unique study on diversity of microbiota of An. stephensi from breeding water, developmental stages and adults. Different culture media used enhanced the isolation of diverse bacteria. The presence of Micrococcus and Leucobacter in different life stages indicates their adaptation in An. stephensi as symbionts which need further evaluation for their role in paratransgenesis.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub] [CITATIONS]  [PubMed]

Background & objectives: Malaria is one of the most infectious and life-threatening vector borne disease in the tropics. Climate change can significantly influence malaria epidemiology and expansion of malaria vectors to hilly regions of Himachal Pradesh in India, hitherto considered areas of low transmission. Entomological surveillance in Kangra district of Himachal Pradesh revealed high density of a proven efficient vector of malaria, Anopheles fluviatilis, but transmission intensity of malaria was found very low. It was therefore considered prudent to investigate the sibling-species composition of An. fluviatilis complex in Kangra valley to ascertain their role in transmission of malaria. Methods: The study was undertaken in six villages in Kangra district of Himachal Pradesh, India. A total of 4446 mosquitoes were collected during the one-year study period (2018) and processed in pools of ten for molecular characterization. DNA extraction and multiplex PCR was performed on 900 An. fluviatilis mosquitoes for differentiation of sibling-species. ELISA was used to detect Plasmodium falciparum and Plasmodium vivax circumsporozoite proteins in 3790 An. fluviatilis samples. Results: Among prevalent mosquito species, An. fluviatilis was the predominant species constituting 69.5% of total mosquito collection. Sibling-species U was found in 92.22% and species T in 7.78% samples assayed. ELISA confirmed the absence of evidence of malaria parasite in any of the An. fluviatilis mosquitoes screened. Based on the difference in the sequences of conserved regions of the 28SrDNA, sibling-species U was confirmed as prevalent in the study villages. Interpretation & conclusion: Study revealed that in Kangra district, An. fluviatilis sibling-species U is predominant followed by species T, and both are non-vectors. The absence of malaria parasite and zoophagic nature of An. fluviatilis established through blood meal analysis, confirmed that both U and T are non-vector sibling-species.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub] [CITATIONS]  [PubMed]

Scrub typhus is an important etiological agent in acute febrile illness in the post-monsoon season in tropical countries. It leads to dreaded complications if left untreated. Acute kidney injury is one such complication. Malaria, syphilis, and HIV have been associated with secondary nephrotic syndrome in pediatric age group. Scrub typhus has been reported only once with nephrotic syndrome. We report a case of scrub typhus-associated nephrotic syndrome with acute kidney injury in a five-year-old female with uneventful outcome

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

[FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Background & objectives: Dengue is one of the most important arboviruses and public health problem associated with increasingly large outbreaks, especially in tropical countries such as Brazil. The state of Minas Gerais, in particular, has had high numbers of cases of this infection in recent years. Methods: Our study evaluated the epidemiological impact of dengue fever in the state of Minas Gerais from the National Health System (Sistema Único de Saúde, SUS) perspective between 2000 to 2015 using the Brazilian Notifiable Diseases Information System (SINAN, notification cases) and Hospital Information System (SIH)/SUS (hospitalization registers) databases. Results: The SUS database recorded 34,996 reports of dengue (International Classification of Diseases [ICD]: A90) as well as 1984 verified cases of severe dengue (ICD-A91). These hospitalizations for dengue and cases of severe dengue generally affected individuals aged 15–24 (17.74%) and 5–14 (20.86%) years, respectively. The epidemiological burden of dengue was substantial in Minas Gerais state, with the highest number of notifications nationally in 2013. Interpretation & conclusion: From retrospective data associated with dengue records, our study sought to better highlight the locations with the largest number of dengue cases in the Minas Gerais state, and contribute to direct educational and surveillance actions of these regions applied to this infection.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Background & objectives: Schistosomiasis is one of the major neglected tropical parasitic diseases caused by a group of blood-feeding worms in the genus Schistosoma. Nigeria ranks highest among all countries worldwide, however, there is a paucity of information on the prevalence of the disease in some parts of the country. Therefore, the research aims to augment available data on the prevalence of Schistosoma haematobium infection among schoolaged children in ten communities in Edo state, Nigeria. Methods: A cross-sectional survey involving 400 school-aged children was conducted in 10 randomly selected communities in Akoko-Edo Local Government Area, Edo State of Nigeria between November 2016 and April 2017. Demographic data of subjects was collected using a structured questionnaire. Urine samples were collected and examined for haematuria and ova of Schistosoma haematobium using a commercially prepared reagent strip (Medi-Test Combi9TM^R) and sedimentation technique respectively. Results: The prevalence of urinary schistosomiasis based on microscopic examination of the urine sediment for the ova of S. haematobium was 17.3%, while haematuria was 22.0%. Mean intensity of S. haematobium oval count ranged between 2.0–4.0/10ml of urine per community. Prevalence was higher among males (24.5%) than females (10.0%)(P<0.05), which was statistically significant. Overall, age group 7–9 years showed the highest prevalence of infection. Farming showed a strong correlation as a parent occupational risk factor in predisposing children to infection as it accounts for 73.9% of all infections. Interpretation & conclusion: Findings indicate that urinary schistosomiasis is still prevalent among school-aged children in Akoko-Edo LGA, which hinders their growth, development and cognitive abilities. Although, mass drug administration is ongoing in some of the communities, re-infection still occurs due to ignorance, occupational factors, lack of portable water and sanitary toilets.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Background & objectives: Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonosis with up to 50% mortality rate in humans. In addition to the role of animals in the transmission of the virus and spread of infected ticks through livestock trade, they can be employed as sentinel hosts for monitoring the infection. Iran is one of the endemic counties for CCHF and the disease has been documented in all provinces. However, in some provinces such as Kohgiluyeh and Boyer-Ahmad, the rate of the disease has been dramatically low. Therefore, this serosurvey was designed to investigate CCHF virus (CCHFV) seroprevalence among livestock in different parts of Kohgiluyeh and Boyer-Ahmad Province. Methods: This study was conducted in 2017, in which, blood samples were collected from 501 sheep and goats from eight different cities of Kohgiluyeh and Boyer-Ahmad Province. CCHFV IgG antibodies were detected in livestock serum samples by specific ELISA assays for detection of ovine and caprine antibodies. Results: In total, four sheep serum of out of 501 (0.8%) livestock samples (3 from Gachsaran and 1 from Dena) had CCHFV IgG antibodies. No significant association was found between CCHFV seropositivity and sex or age of animals (P>0.05). Interpretation & conclusion: Our findings suggest a minor CCHFV circulation in Kohgiluyeh and Boyer-Ahmad Province, Iran. However, due to the notion that outbreaks of tick-borne infections is hard to predict; steady and comprehensive monitoring programs especially in ticks and animals would be critical for understanding the circulation on the pathogen in a region.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Background & objectives: Trypanosoma cruzi, the causative agent of American trypanosomiasis, has been reported in 180 mammalian species and 154 triatomines species of Neotropic. This is a clonal parasite with variable biological behaviour, associated with the genetics of the parasite and its hosts. To know the eco-pathogenic complex of this zoonosis, it was proposed to characterize T. cruzi isolates obtained from triatomines and domestic, peridomestic and wild mammals of the eastern and central-western regions of Venezuela. Methods: The positivity to T. cruzi was established and the isolates were genetically characterized by PCR amplification of the mini-exon gene, the DNA coding for 24Sa and 18S rRNA, and polymorphic sequences-RFLPs. The sampling sites were georeferenced using the MapSource Software and ArcGis 9.3 programs to generate distribution maps of the isolates. Results: Of the 460 hosts (205 triatomines and 255 mammals), 49% were positive for the parasite. On the other hand, 38 isolates obtained from the triatomines and 23 isolates obtained from mammals were evaluated. The TcI genotype predominated in most of the isolates; however, in those obtained from triatomines the presence of the TcIII genotype in single infections and TcI + TcIII or TcI + TcIV in mixed infections was also evidenced. Interpretation & conclusion: There is a possibility that the triatomines act as biological syringes for these genotypes associated exclusively to them. The heterogeneity in T. cruzi isolates demonstrated the complexity of parasitosis in these regions, presenting its control and prevention as a challenge.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Background & objectives: Jammu and Kashmir is bestowed upon by great climatic condition favourable for people but the vectors have utilised these conditions to gain access into the state. Vector Borne Diseases (VBDs) were restricted to the spread of malaria and dengue since past two decades, but now, these diseases have widened their geographical reach and in last six years chikungunya, leishmaniasis and Japanese encephalitis have been reported from the state. These VBDs are a threat to thousands of people in the state as they cause huge mortality and morbidity under extreme cases. Methods: A hospital-based survey on the VBDs was carried out with the aim of studying the prevalence of major VBD found in the Jammu district taking into account the past records provided by the Directorate of Health Services, Jammu. Results: The study revealed that malaria, in the past 14 years, has now shown a clear declining trend and dengue cases have shown a very uneven trend with maximum cases in 2013. Leishmaniasis was reported for the first time in the division in 2013, while it was not until 2016 when single case of chikungunya was reported from Jammu division. First outbreak of Japanese encephalitis in the region occurred during 2018 from only Doda district. Interpretation & conclusion: The present study showed that despite having congenial environmental conditions, Jammu division faces a great threat of VBDs and the increase in the number of cases in future cannot be ruled out. Japanese encephalitis registered its presence for the first time in the division.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Background and objectives: Fever defervescence in scrub typhus, a zoonotic bacterial infection is used as a surrogate marker of disease resolution. Failure of fever defervescence prompts clinicians to suspect alternate diagnoses and treatment. In this observational study, various treatment regimens were correlated with clinical outcomes. Methods: All adult patients with a diagnosed scrub typhus were included; various antibiotic regimens used and clinical outcomes were studied. Data was analyzed using SPSS software for windows 16, with a 2-sided P-value of 0.05 or less was considered statistically significant. Results: In 177 hospitalized patients with scrub typhus, combination therapy (doxycycline and azithromycin) was used in 74 subjects with doxycycline and azithromycin used in 46 and 57 subjects, respectively. Incidence of delayed defervescence was seen in 31.6%, Combination therapy being preferred in sicker patients (SOFA score 8.82). Presence of respiratory dysfunction was associated with a delay in fever defervescence [risk ratio 2.50(1.18-5.3)]. Patients receiving doxycycline did better in terms of oxygen requirement and the presence of hypotension. The overall case fatality rate was 5.6%. The severity of illness rather than the choice of antibiotics predicted the outcome in scrub typhus. Interpretation & conclusion: Combination therapy with doxycycline and azithromycin is the most common regimen used. Incidence of delayed defervescence (31.6%) is increasing despite therapy and the involvement of respiratory dysfunction is an independent predictor of delayed fever defervescence.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Background & objectives: Dengue is considered endemic in many countries in the world including the Philippines, and factors associated with dengue infections have not been adequately explored in the Philippines. The aim of this study was to assess demographic and location-related factors associated with different classifications of dengue: mild dengue, dengue fever, and hemorrhage dengue fever. Methods: This study used consolidated dengue reports of 18482 individual cases from the Provincial Hospital (PH) of Cavite province from 2009–2014 and clinical classifications of dengue used by the Philippine Integrated Disease Surveillance and Response (PIDSR). Multinomial logistic regression and marginal effects were used to analyze factors associated with different dengue classifications. Results: Living in densely populated cities and municipalities, individuals aged 19 years and below, and being female were closely associated with severe dengue (DHF) type, while being male and older (above 19 years old) decreased the risk of contracting severe dengue. Interpretation & conclusion: Our study provides a preliminary assessment of association between demographic factors (gender and age-group), locations (municipalities and cities); and three classifications of dengue (mild, moderate, and severe) in Cavite province in the Philippines. To establish whether dengue is linked to populated areas, age and gender will require further assessments.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Increased outbreaks of mosquito borne diseases like the deadly parasitic disease, malaria and arboviruses like Zika, yellow fever and dengue viruses around the world have led to increased interest in traps that could effectively be used against mosquitoes. For example, a Google search at the time of this writing, asking, ‘which is the best way of trapping mosquitoes?’ produced 35.5 million search results. Regardless of the interest in the subject, scientists have yet to find a definitive answer to these questions. One area that has been exploited as a potential source of efficient traps for mosquitoes is host odour baits. Since mosquitoes are attracted to their hosts through odours produced by the hosts, it’s highly likely that synthetic chemical blends based on host odours could provide a solution. Most mosquito species have 2 hosts: vertebrate animals and vascular plants. Amongst the vertebrates, most diseases spread by mosquitoes are to humans. Considerable research has therefore been conducted on human odours that elicit attraction in mosquitoes, with emphasis on compounds from sweat and skin. Interest on plant volatiles is currently gathering pace because unlike human odours that only attract host seeking female mosquitoes, plant odours can attract both male and female mosquitoes of all gonotrophic stages. This review article concentrates on some of the chemical compounds in human and plant host odours that have shown a potential as attractants to mosquitoes especially Aedes aegypti and Anopheles gambiae s.l.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Arboviruses are responsible for several emerging and re-emerging infectious diseases, with dengue, Zika virus disease and Chikungunya fever being the most important arboviral diseases nowadays. Infection of these viruses depends primarily on its ability to replicate and disseminate in mosquitoes. Since these viruses are enveloped, viral replication, assembly and release occurs in the cellular membranes, which depends on the manipulation of host lipid metabolism. Specifically in mammalian cells replication, they use host lipids to establish a compartment known as replication complex that contains the replicase complex. This complex includes viral RNA, proteins and host factors necessary for a successful replication in mammalian cells. Although little is known about extrinsic factor(s) needed for arbovirus replication in vectors,recent reports show that high lipid concentrations are related with increased viral replication in mosquito cells infected with dengue, Zika and Chikungunya viruses. Here, we present a review that focuses on the cellular mechanisms and the lipid environment alteration in mosquito vector after arbovirus infection and their relationship with arbovirus replication.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]

Serology remains the mainstay for diagnosis of scrub typhus. In central India, diagnosis of this neglected emerging zoonotic disease suffers due to lack of standardized region-specific cutoff value and diagnostic test. Henceforth, standardized region-specific cutoff value for diagnostic ELISA play a significant role in initial treatment of patients and to differentiate other febrile diseases in endemic setup. A total of 144 patients of all age groups with acute undifferentiated febrile illness patients, forty healthy controls, dengue and chikungunya positive thirty-five samples in each category, respectively were enrolled in the study and subjected to IgM ELISA (InBioS, International, Inc.). Samples showing OD value more than 0.5 in IgM ELISA, were subjected to nested PCR. Both, receiver operating characteristic (ROC) curve and healthy volunteer samples mean with +3 SD were considered to generate region specific cutoff OD value. A total of 48 patients were diagnosed as cases of scrub typhus through IgM ELISA. Out of 48 samples, 30 were positive by nested PCR. The ROC curve analysis revealed a diagnostic ELISA cutoff value of 0.73 with sensitivity and specificity of 95% and 100%, respectively. The cut off arrived from healthy volunteer is mean OD + 3 SD is 0.72. Considering the significance of scrub typhus diagnosis for treatment and to understand disease dynamics in region wise, the cutoff value of >0.72 for diagnostic ELISA for Madhya Pradesh in central India can be used.

[ABSTRACT]  [FULL TEXT]  [PDF]  [Mobile Full text]  [EPub]  [PubMed]