Ticks are blood sucking ectoparasite that transmit several pathogens to humans and animals. Tick management focusing on use of chemicals has several drawbacks including development of multi-acaricide resistant tick populations. To minimize the use of chemicals on animals and on the environment, immunization of natural hosts is considered a viable component of Integrated Tick Management System. Most of the tick vaccine trials are focused on single antigen immunization directed against homologous challenge. From commercial point of view, vaccination against one given tick species is not a feasible option. In this context, multi-antigen vaccines comprising of candidate antigens of multiple tick species or both ticks and tick-borne pathogens have commercial potential. Different strategies are considered for the development of multi-antigen tick and/or tick-borne pathogen vaccines. Further, the efficacy of vaccine can be improved by adopting the ‘omics’ tools and techniques in selection of novel antigens and efficient delivery like Lipid Nano Particle (LNP)-mRNA vaccines, viral vector vaccine, live vector vaccine etc. into the host. The subject has been reviewed to address the current status of multi antigen tick vaccines and formulations of the future strategies for the control of TTBDs of human and animals.

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Background & objectives: Japanese encephalitis (JE) and West Nile virus (WNV) are two mosquito-borne diseases of medical and veterinary importance. Climate impacts in certain ecosystems are better understood; however, coastal brackish water ecosystems and their role in vector borne viral diseases have not been well studied. Hence, the aim of this study is to evaluate the distribution, spatial pattern as well as the screening of these mosquitoes for JE and WN virus in coastal area of Alappuzha district, Kerala, India. Methods: Immature mosquitoes were collected using dipper methods along the coastal wetlands areas. Adult mosquitoes were collected in four sampling sites with light trap filled with dry ice, operating overnight. The collected mosquitoes were identified by species, using the taxonomic keys. Mosquitoes were pooled for virus detection. Water samples were collected using standard methods. Results: The total quantity of rainfall and salinity varied from zero to 365.2 mm and from 1.5 to 28 ppt respectively. A total of 10,695 adult mosquitoes and 38,083 immatures revealed the presence of five genus and 23 species. The most predominant species was Culex tritaeniorhynchus. Immature collections Cx. sitiens was the only one species collected during the summer season and in the monsoon season the pond was replaced by fresh water mosquitoes such as Cx. tritaeniorhynchus and Cx. gelidus. A total of 186 pools were screened for JEV and WNV. However, none of the pools were found as positive for the virus. Interpretation & conclusion: The major vector of JEV Cx. tritaeniorhynchus and Cx. gelidus have adapted to immature development in coastal brackish water habitats. The public health authorities need to recognize thepotential impact on human health of brackish water-adapted mosquito vectors that weretraditionally considered to be freshwater species, and take appropriate surveillance and control measures.

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Background & objectives: Indoor Residual Spraying (IRS) is an important part of malaria prevention and control strategies for villages with annual parasitic incidence (API) of more than 5, or other criteria by National Program of the country. At the time of conception of the study, i.e., in 2012, district Mewat in Haryana state, India was malaria endemic including 35 malaria high risk villages with API more than 5. The current study aimed to improve acceptability of IRS among the residents of Mewat district. Methods: This was a community based interventional study. Out of the 14 sub-centers, there were 12 sub-centers catering the population of 79 villages, out of which 35 villages had API of more than five, and hence, fulfilled the criteria for regular IRS. Considering sub-center as the unit of randomization, out of all the 12 sub-centers which cater population of villages with API > 5, equal number of the sub-centers matched according to the population size of those villages were assigned to the intervention and non-intervention (control) groups by randomization using lottery technique. The intervention comprised community sensitization through community meetings, wall paintings and distribution of pamphlets. Baseline and post intervention acceptability of IRS was measured and compared. Results: There was 21.7% (95% CI 16.12 to 27.15) increase in intention to accept IRS as per guidelines, and 15.2% (95% CI 9.50 to 20.80) increase in the actual acceptance of IRS in intervention group of villages in Mewat district. Interpretation & conclusion: The intervention can bring about significant increase in the acceptability of IRS which is an important component of malaria control under national programme in district Mewat, Haryana, India.

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Background & objectives: Japanese encephalitis (JE), is a vaccine preventable mosquito borne arboviral disease. The State Health Department of West Bengal, India started a vaccination programme using live attenuated, single dose JE vaccine (SA-14-14-2) in children aged 1-below15 years since 2006 in five districts. The objectives were to compare Sample Positivity Rates (SPR) of Acute Encephalitis Syndrome (AES) cases for JE between vaccinated & unvaccinated districts and observe trend of SPR & Cumulative Incidence in vaccinated districts for three years. Methods: The study was based on the analysis of surveillance data from all tested AES cases including confirmed JE (IgM ELISA) from all JE testing facilities existent in the state during the study period (2011–13). Calculation of Cumulative Incidence, Odds Ratio (OR) with 95% CI, Preventive Fraction and Chi Square for trend (for SPR) was done. Trend of incidence was assessed by linear regression. Results: In three years, 5 vaccinated districts contributed 945 AES and 88 JE cases (SPR - 9.3%) compared to 1807 and 254 (SPR - 14.1%) JE cases in 14 unvaccinated districts. Effectiveness of vaccination was evident by gradual decline of Odds Ratio in favour of vaccinated districts. Vaccination effectiveness of 68% overall and 80% [OR = 0.20 (0.10 - 0.41)] in below 15 years were observed. Trend of SPR was found significantly declining in most of the vaccinated districts. Interpretation & conclusion: Significant reduction in sample positivity rate over three years in most of the vaccinated districts indicated that the vaccination programme had been gradually effective.

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Background & objectives: Japanese encephalitis (JE) is a major public health problem in many states of India. Uttar Pradesh state contributes 75% of the total cases reported. A longitudinal study was undertaken to find out the seasonal abundance, infection in the JE vectors in Gorakhpur region of Uttar Pradesh, and intervention strategies like indoor residual spraying and long-lasting insecticidal nets were adopted. Methods: The vector abundance was monitored from July 2013 to August 2016 at fortnightly intervals and identified using standard mosquito identification keys and screened for viral infection. Intervention measures like indoor residual spraying with lambda-cyhalothrin 10% WP at 25 mg/m² in 58 gramasabha in Bhathat Block and long-lasting insecticidal nets were distributed @ 2 LLIN for each household with 5-6 members in 5 villages of Korabar block. Results: A total of 5,36,609 mosquitoes constituting 34 species and 10 genera were collected during this study period. Among the JE vector, peak abundance of Culex tritaeniorhynchus was recorded just before the JE season from July to October in all the blocks. There was a marked reduction in the density of Cx. tritaeniorhynchus from July compared to baseline year 2014 in Bhathat Block where indoor residual spraying (IRS) was performed in June 2015. The vector density declined in 5 villages of Khorabar Block where long-lasting impregnated bed nets (LLINs) were distributed during July 2016. Interpretation & conclusion: The present study provided knowledge about the seasonal JE vector density and JE virus infection in mosquitoes during the monsoon season in Gorakhpur region of Uttar Pradesh. IRS and the personal protection measure like LLINs were distributed to interrupt the JE transmission in this area which gave encouraging results.

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Background & objectives: Cardiac injury in scrub typhus is uncommonly reported. We studied the incidence and clinical significance of cardiac involvement among seventy consecutive adult patients of scrub typhus, using circulating cardiac biomarkers, including N-terminal pro-B-type natriuretic peptide (NT-pro-BNP), troponin T, creatine kinase-muscle/brain isoenzyme (CK-MB) and 2D-echocardiography. Methods: This was a hospital-based prospective cohort study conducted in the medical emergency of PGIMER, Chandigarh, India. Seventy consecutive patients aged 12 years and above with the diagnosis of scrub typhus were enrolled. Results: Elevations of NT pro-BNP, troponin T, and CK-MB levels were observed in 70 (100%), 51 (72.8%), and 29 (41.4%) patients, respectively. Echocardiography detected reduced ejection fraction (EF) in 30 patients (42.8%) with mild reduction (EF 45-54 %) in 20 (28.5%) and moderate reduction (EF 30-44%) in 10 (14.3%). The age showed a significant difference with EF (p-value 0.003), and the patients with moderate reduction were younger (mean age of 20.7 ± 5.6 years). Pericardial effusion was found in nine patients (12.9%). Increased circulating levels of all the three cardiac biomarkers showed statistically significant association with a systolic dysfunction on echocardiography, and elevated CK-MB level further predicted a longer duration of hospital stay (p-value 0.002). No statistically significant association was observed between cardiac biomarkers or reduced EF and mortality. Interpretation & conclusion: Cardiac injury is a common condition among patients with scrub typhus admitted in a medical emergency; however, it does not influence in-hospital mortality.

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Background&objectives: Changes in parasite biology, particularly the gametocytogenesis process, could be one of the important contributing factors for worldwide malaria resurgence. The present study investigated the prevalence rates of pretreatment gametocyte carriage and density in Plasmodium falciparum and P. vivax infections in the low malaria-endemic area on the Thai-Myanmar border. Methods: One hundred and twenty-six blood samples were collected from patients with signs and symptoms of malaria who attended malaria clinics. Malaria positive cases detected by microscopic examination were confirmed by species-specific nested-PCR in 97 (29 and 68 samples for P. falciparum and P. vivax, respectively). Results: The proportion of P. vivax and P. falciparum-infected samples was 70.1: 29.9%. The density in P. falciparum positive samples [median (95%CI): 10,340 (5280-19,200) μ/l] was significantly higher than P. vivax positive samples [4508 (3240-6120) μ/l]. Sixteen out of twenty-nine (55.2%) and 36 out of 68 (52.9%) P. falciparum- and P. vivax-infected samples, respectively, were gametocyte-positive. Gametocyte density in the P. falciparum-infected[124 (69-253) /μl] was significantly higher than that of the P. vivax-infected [54 (45-70)/μl] samples. A significant correlation between gametocyte density and pretreatment parasitemia was only detected in P. falciparum-infected, but not P. vivax-infected samples. Interpretation & conclusion: The observed high prevalence rates of pretreatment gametocyte carriage of both malaria species, which serves as a large malaria reservoir, particularly in P. falciparum infection, could have a significant impact on malaria control in the endemic populations.

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Background & objectives: In imported falciparum malaria various life-threatening complications involving multiple organ systems can ensue rapidly and unpredictably. Early recognition of high disease severity is mandatory to provide optimal care, thereby reducing mortality. However, validated tools allowing precise assessment of disease severity are unavailable for imported malaria. This study aimed to identify indicators of high disease severity apparent on admission. Methods: Fifty-four adult cases of severe imported falciparum malaria treated between 2001 and 2015 on various intensive care units of the Charité University Hospital, Berlin, were retrospectively grouped according to their admission coma-acidosis malaria (CAM) score. The association of sociodemographic and clinical parameters with disease severity was assessed by multivariable logistic regression. Results: Nineteen female (35%) and 35 male (65%) patients (median age: 44 years) were enrolled. The admission CAM score was 0 in n=24, 1 in n=15, 2 in n=10, 3 in n=3, and 4 in n=2 subjects. Thus, 5 patients (9.3%) had a predicted mortality risk of >20%. Higher maximum heart rates (p=0.002), lower baseline haematocrit (p<0.001), increased oxygen demand (p<0.001), and infiltrates on the admission chest X-ray (p=0.019) were independently associated with higher disease severity in multivariable analysis. Interpretation & conclusion: In addition to the prognostic key parameters metabolic acidosis and impaired consciousness reflected by the CAM score, symptoms of respiratory distress and shock as well as profound anaemia help identify patients with highest disease severity. These indicators may guide clinicians to prompt targeted interventions at the earliest possible stage and may thus help improving survival.

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Background &objectives: The diagnosis of Plasmodium falciparum malaria is widely dependent on the P. falciparum histidine rich protein 2 (PfHRP2) antigens based rapid diagnostic tests. There are few possible factors like Pfhrp2 polymorphism, Pfhrp2 deletion and density of malaria parasite which can affect the sensitivity of the Pf-HRP2-based RDT. The primary objective of the investigation was to check whether the Pfhrp2 gene deletion is the primary cause of RDT false negative cases. Methods: Febrile patients from three districts of Chhattisgarh, India were screened for malaria during 2016–2017 by microscopy and RDT. All microscopy P. falciparum positive samples were validated by PCR. Microscopy positive and RDT negative samples were analyzed for the presence of Exon 2, across Exon 1-2, upstream and downstream of both the Pfhrp2 and Pfhrp3 genes fragment by PCR. Results: Out of 203 screened samples, 85 were detected positive for P. falciparum malaria based on microscopy and PCR. Among these 85 P. falciparum positive samples, 4 samples were observed Pf-HRP2 RDT negative. Although, it signified that the RDTs used were reliable with sensitivity of 95.3% (81/85). 3/4 PfHRP2-RDT negative samples of the P. falciparum isolates exhibited complete deletion of Pfhrp2 and Pfhrp3 genes and one sample was found RDT false negative due to high parasite density. Interpretation & conclusion: Pfhrp2 and Pfhrp3 deletions that result in false negative RDTs were uncommon in our setting. The continued monitoring of RDTS which results in false negative tests due to Pfhrp2/3 gene deletion is the need of the hour for an effective malaria elimination strategy.

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Background & objectives: For decades, the city of Belém in Brazil’s eastern Amazon was the second city in the country with highest prevalence of cases of filariasis due to Wuchereria bancrofti infection. However, this prevalence decreased over time until reaching null records, concomitantly with a decrease in frequency of recorded hydrocele cases. In this context, we analyzed cross-sectional data to evaluate the degree of correlation between prevalence of positive blood microfilariae results during surveillance screening occurred along 54 years (1951–2005) and prevalence of hydrocele cases recorded in the same time period. Methods: The dataset regarding hydrocele cases was obtained from two local hospitals. The Endemic Diseases Control Division of the Health Surveillance Department of the Municipal Health Department of Belém provided dataset regarding positive blood microfilariae cases. Prevalence calculus and linear correlation statistics were performed. Results: Both positive blood microfilariae and hydrocele cases are well correlated statistically in absolute frequency (r = 0.871, 95%_CI = 0.788 to 0.923, R² = 0.759, p < 0.0001) and in prevalence (r = 0.835, 95%_CI = 0.732 to 0.901, R² = 0.698, p < 0.0001). Interpretation & conclusion: We have concluded that blood microfilariae detection and hospitalized hydrocele cases are well correlated in our dataset. In addition, these results support the hypothesis that hydrocele prevalence can be useful to filariasis surveillance and control in endemic areas. However, limitations to hydrocele prevalence as an epidemiological indicator of filariasis are evidenced.

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Background & objectives: Visceral leishmaniasis (VL),a protozoan disease caused by Leishmania infantum is a major public health problem and cause of death among infants aged under 1 year and the elderly in endemic foci of Iran. The aim of this study is to determine the status of L.infantum infection in stray dogs from Meshkin-Shahr, a typical endemic area of VL in Iran. Methods: Sixty-eight randomly trapped stray dogs in Meshkin-Shahr area were tested for L. infantum infection using the direct agglutination test (DAT) from June to October 2016. The confirmation of seropositive samples was performed by Microscopic slides of spleen, culture and then PCR. The molecular methods performed by ITS1-PCR, RFLP-PCR and kDNA-PCR. The allof kDNA -PCR products were sequenced. Results: Out of 68 examined stray dogs, 17 (25.0%) were positive for L. infantum by DAT (1:320 titers or higher). Parasite test showed that all of seropositive samples have amastigote forms in their spleens but only 3 out of them could be cultured. The kDNA-PCR confirmed all of seropositive samples but ITS1-PCR and RFLP-PCR only confirmed 3 out of 17 (17.6%) seropositive samples. The sequenced products showed 94% homology with L. infantum. Interpretation & conclusion: The results showed a high prevalence of L. infantum infection in dogs in an endemic area of CVL and it provided key information for designing control programs against canine and human leishmaniasis.

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Background & objectives: Universal coverage of population with long-lasting insecticidal nets (LLINs) living in endemic areas inhabited by ethnic tribal communities or in difficult to reach areas was found effective for disease control where other interventions such as indoor residual spraying have limited success because of operational issues. Evaluation of different LLINs with varied insecticides and fabrics are being evaluated to meet the demand of new products. This study was undertaken on two brands of LLINs, DuraNet© and Interceptor® that varied in fabric and manufacturing technologies to assess the usability in field conditions for atleast three years. Methods: In large-scale field trials DuraNet©, alpha cypermethrin incorporated polyethylene net, was evaluated in Odisha state while, Interceptor® net, alpha cypermethrin coated polyester net was evaluated in Chhattisgarh and Gujarat states for a period of three years following WHO guidelines. Durability, usage pattern and washing behavior were monitored through periodic surveys and physical examination of nets. Results: Survivorship of both the nets was 84–100% and every night usage rate was >62% in all seasons. Washing frequency was largely within the prescribed limits. The proportion of DuraNet© with holes was 26.7% in year one 74% in year three. In Gujarat, proportion of Interceptor® nets with holes at six months was 33.3% increased to 87% in year three and in Chhattisgarh, 6.7% after six months to 93.3% after three years of use respectively. Interpretation & conclusion: Both the nets revealed a useful life of three years under the field condition

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Background & objectives: Presence of dengue is reported from India since 1960s. Secondary dengue infection may be more severe than primary, hence, distinction between primary and secondary dengue is essential. A way to detect secondary dengue is demonstration of anti DV IgG in patients’ serum. In this study we explored the association of dengue severity with anti DV IgG positivity. Methods: Laboratory confirmed cases of dengue (positive for anti DV IgM/ NS-1 Antigen/ DV –RNA), presenting to the hospital within 7 days of illness, were consecutively enrolled for a period of one month (September 1–30, 2018) and were tested for anti DV IgG in their serum. All PCR positive samples were serotyped. Cases positive for anti-dengue IgG were labeled as secondary cases. Clinical details were collected to assess the severity of illness. Association of dengue severity with anti DV IgG positivity was calculated. Results: Of the 128 dengue positive cases, 89 (69.5%) were anti DV IgM positive, 72 (56.3%) were Dengue NS-1 positives and 37 (28.9%) were DV-RNA positive. Only 39 (30.5%) cases were having detectable anti-dengue IgG in their serum (secondary dengue). Anti-dengue IgM positivity was significantly higher in secondary dengue cases. No association of anti DV IgG positivity was seen with severity of dengue illness. Interpretation & conclusion: No association of IgG positivity with severity of illness was seen. D4 serotype is first time reported from Uttar Pradesh, India

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Dengue is spread by the bite of infected Aedes aegypti mosquito. It is usually a self-limiting viral infection but sometimes complicates to mortality. In the last few decades, literature has shown that clinical and biochemical profile of dengue is expanding due to the addition of unusual manifestation day by day. Hereby, we report a young male student suffering from dengue complicated to retinal hemorrhage and severe pancytopenia who recovered near fully on treatment.

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