Awareness of Mosquito Bite and Preventive Methods Adopted against their Bites

Mosquitoes are the utmost common disease vectors worldwide. Newly in India mosquito borne diseases have revealed as a big threat to public health specially disease like Dengue, Malaria and Chikungunya. Puducherry is said to be endemic zone for malarial spreading and other such kinds of diseases. Anopheles, Aedes and Culex are commonly seen in Puducherry. Therefore, considerable effects are taken to create the awareness against such kinds of insect- borne particularly, on mosquito bites made together for local citizens. The present study aimed to spread such kind of awareness and related practices on disposing mosquitoes’ supporting places, their eggs for maximum prevention in Puducherry rural areas. A pilot study was conducted among the small group of people and based on it, the study questioner was prepared. The objective of the survey was to study the awareness, attributes and practices about mosquito borne diseases in urban areas and it explore various myths about mosquito borne diseases.

Enhancement of alphavirus replication in mammalian cells at sub-physiological temperatures

Chikungunya virus (CHIKV) is a re-emerging Alphavirus transmitted by Aedes mosquitoes and causing fever, rash and arthralgia. Currently there are no vaccines or antiviral agents against CHIKV, therefore it is important to understand the molecular details of CHIKV replication. In this regard, the function of the Alphavirus non-structural protein 3 (nsP3) remains enigmatic. Building on previous studies (Gao et al, 2019), we generated a panel of mutants in a conserved and surface exposed cluster in the nsP3 alphavirus unique domain (AUD) and tested their replication phenotype using a sub-genomic replicon (SGR) in mammalian and mosquito cells. We identified three mutants that replicated poorly in mammalian cells but showed no defect in mosquito cells. We further showed that these mutants were temperature-sensitive, rather than species-specific, as they exhibited no replication defect in mammalian cells at sub-physiological temperature (28°C). Similar effects were observed in the context of infectious CHIKV as well as a closely related virus: O’Nyong Nyong virus (ONNV). Intriguingly, this analysis also revealed that the wildtype SGR replicated much more efficiently at sub-physiological temperature as compared to 37°C. This was not due to impaired interferon responses as this enhancement was also observed in Vero cells. Neither was this due to a defect in the phosphorylation of eIF2α as treatment with ISRIB, an inhibitor of global translation attenuation, did not compensate for replication defects at 37°C. However, we noticed significant differences between the sizes and numbers of virus-induced stress granules (SG) at physiological and sub-physiological temperatures. As cells in the periphery will be at sub-physiological temperatures, and these will be the first cells infected in the mammalian host following a mosquito bite, we propose that alphaviruses have evolved mechanisms to limit antiviral responses in these cells to promote viral genome replication.Author summaryChikungunya virus (CHIKV) is a re-emerging arbovirus. It is transmitted by Aedes species of mosquitos and poses massive epidemic threats. Arboviruses are unique in that they must be able to replicate efficiently in both the mosquito vector and the mammalian host, and therefore at different temperatures. Importantly, the first cells infected in the mammalian host following a mosquito bite will be in the skin and therefore at sub-physiological temperature (lower than 37°C). Here we show that mutants within one of the CHIKV proteins (nsP3) were unable to replicate at 37°C but replicated efficiently in mammalian cells at a sub-physiological temperature (28°C). We also showed that the wildtype virus replicated more efficiently at 28°C in comparison to at 37°C in mammalian cells. We investigated the mechanism behind this phenomenon and showed that at sub-physiological temperatures the virus induced the formation of smaller and more numerous cytoplasmic stress granules. We propose that alphaviruses have evolved mechanisms to promote their replication in mammalian cells at sub-physiological temperatures to facilitate infection of mammals via a cutaneous mosquito bite.

Three Immunocompetent Small Animal Models That Do Not Support Zika Virus Infection

Zika virus (ZIKV) is a mosquito-borne flavivirus that is primarily transmitted to humans through the bite of an infected mosquito. ZIKV causes disease in infected humans with added complications of Guillain-Barré syndrome and birth defects in infants born to mothers infected during pregnancy. There are several large immunocompetent animal models for ZIKV including non-human primates (NHPs). NHP models closely reflect human infection; however, due to sample size restrictions, investigations into the effects of transmission route and the impacts on disease dynamics have been understudied. Mice have been widely used for modeling ZIKV infection, yet there are few ZIKV-susceptible immunocompetent mouse models and none of these have been used to investigate sexual transmission. In an effort to identify a small immunocompetent animal model to characterize sexual transmission of ZIKV, we attempt experimental infection of multimammate mice, New Zealand white rabbits, and Hartley guinea pigs. The multimammate mouse is the natural reservoir of Lassa fever virus and has been identified to harbor other human pathogens. Likewise, while NZW rabbits are susceptible to West Nile virus, they have not yet been examined for their susceptibility to infection with ZIKV. Guinea pigs have been successfully used as models for ZIKV infection, but only in immunocompromised life stages (young or pregnant). Here, it was found that the multimammate mouse and New Zealand White (NZW) rabbits are not susceptible ZIKV infection as determined by a lack viral RNA in tissues and fluids collected. Sexually mature male Hartley guinea pigs were inoculated subcutaneously and by mosquito bite, but found to be refractory to ZIKV infection, contrary to findings of other studies in young and pregnant guinea pigs. Interestingly, here it is shown that adult male guinea pigs are not susceptible to ZIKV infection, even when infected by natural route (e.g., mosquito bite). Although a new small animal model for the sexual transmission for ZIKV was not established through this study, these findings provide information on outbred animal species that are not permissive to infection (NZW rabbits and multimammate mice) and new information surrounding limitations of a previously established animal model (guinea pigs).

Case Report: Osteomyelitis of the Proximal Phalanx of the Finger in Patient With Ollier Disease

Ollier disease is a rare congenital pathology characterized by the growth of enchondromas in bones, accompanied with their deformities, fractures, and the risk of malignancy. A 39-year-old patient with Ollier disease (acroform with lesions of hands and feet) suffered a rapid development of osteomyelitis of the proximal phalanx of the ring finger after a mosquito bite. The condition localized in the area of enchondroma. Surgical treatment included osteonecrectomy in the phalanx and enchondroma with excision of non-viable surrounding soft tissues, drainage of the surgical wound and the imposition of primary sutures. Morphological analysis confirmed the presence of ectopic embryonic cartilage specific for Ollier disease and the bone destruction. The excised tissues were infiltrated with immune cells and had signs of periosteal chronic inflammation including fibrosis and hyalinosis. These changes, which occurred long before the mosquito bite, became a favorable background for the development of a purulent infection.

70 Measuring Itch Intensity in Young Children with Burns: What We Learnt from Parents. A Mixed-Methods Study

Introduction Despite the persistence and debilitating symptoms among inflicted children and their families, little is known about children’s itching behavior as perceived and described by parents. This study examined the parental description of young children’s itching behavior corresponding to the itch intensity rating, which can inform the future development of itch measurements for young children. Methods This analysis was part of a larger descriptive study that examined parental behavioral and psychological responses to children’s itch following the child’s unintentional burn injury. Parents of young children with deep second or third-degree burns were recruited. Parents were asked to rate the child’s itching intensity under four situations during the 7-day time frame using a 0–10 numerical rating scale (0 indicates no itch, and 10 indicates the worst itch possible). Parents were subsequently interviewed to describe the child’s observed behavior that reflected the itch intensity rating. The four itch situations were the current itch, the worst intense itch, the least intense itch, and the itch by a mosquito bite. Qualitative data were analyzed using inductive content analysis methods. Results Twenty parents of children 34 (±11.5) months old participated in the study. The average length of time since the child’s burn accident was 6.4 (±3.1) months. The mean ratings of the current itch, the worst intense itch, the least intense itch, and the itch by a mosquito bite were 3.45 (±2.4), 8.35 (±2.3), 1.5 (±1.7), and 4 (±1.2), respectively. Two themes that described a child’s itching behavior were identified: the level of a child’s needs for parental comfort and the frequency and disturbance (to activity and sleep) of scratching behavior. Conclusions Results suggest that the parent’s description of a child’s needs for parental comfort and scratching behaviors may serve as objective indicators of itching intensity. Interpreting inching intensive based on a child’s needs for parental comfort offered a creative way to evaluate itch considering the developmental perspective in young children. Future development of itch measures for children under 5 years of age shall consider these two important aspects.

Sociodemographic predictors of knowledge, mosquito bite patterns and protective behaviors concerning vector borne disease: The case of dengue fever in Chinese subtropical city, Hong Kong

Geographic pattern of dengue fever is changing due to the global environmental and climate changes in the 21st century. Evidence of community’s knowledge, mosquito bite patterns and protective behavior practices in non-endemic regions is limited. This study examined the knowledge of dengue, mosquito bite patterns, protective behavior practices and their associated factors in Hong Kong, a non-endemic subtropical city. A population-based random telephone survey (n = 590) was conducted three weeks after the government announcement of a local dengue outbreak in August 2018. Sociodemographic status, awareness, knowledge, protective measures, bite patterns of mosquito were collected. Results indicated high level of community awareness of the local outbreak (95.2%), symptom identification (84.0%) and adoption of at least one mosquito protective measures (nearly 80%). About 40% of respondents reported that they were bitten by mosquitoes during the study period, a high mosquito season in Hong Kong. Mosquito bites were prevalent near grassy area (63.4%), at home (42.6%) and at public transportation waiting spots (39.6%). Younger people (< 25 years old), female, those who lived on lower floors (≤the 6th) and near grassy area were at higher risk of mosquito bites at home. Respondents perceived higher threat of dengue to society were more likely to practice mosquito prevention. While residential factors affected their indoor prevention, other socio-demographic factors affected the outdoor prevention. Practicing prevention behaviors were associated with self-reported mosquito bite at home. Furthermore, the general prevention uptake rate unchanged after the announcement of local dengue outbreak. Although the uptake rate of protective measures during August was high, 40% participants reported they were bitten. Also public locations are more common area for bites, which suggested stronger mosquito prevention and control on public environments and more personal protective behaviors should be advocated.

Knowledge, Awareness and Practices on Dengue Fever in Rural and Urban Communities

In the recent years dengue fever has become global public health concern as there has a dramatic increase of cases of dengue in tropical and subtropical regions around the world, predominantly in urban and rural areas. A community based cross sectional study was conducted among purposively selected 347 participants to ascertain the knowledge, awareness and practices on dengue fever in rural (n=196) and urban (n=151) communities of the Sylhet division, Bangladesh. Mosquito bite as mode of spread (61.22%, 82.12%), Aedes mosquito as the vector (40.83%, 64.52%), day as biting time (40.83%, 64.52%), stagnant water as breeding place (58.16%, 74.83%) and removal of water stagnation as eliminations of breeding place (40.31%, 64.90%) was mainly reported by study participants respectively in rural and urban communities. Fever (53.7%, 68.27%) was identified as a leading symptom of dengue fever. Using of bed nets (61.73%) was a conjoint recognition in rural whereas window screen (40.40%) in urban as effective measures for controlling mosquito bite. Besides preventive measures like use of bed nets (47.96%, 27.81%), window screen (7.14%, 48.34%) and for control measures removal of water stagnation (31.12%, 58.94%) was mostly utilized method in both settings. The awareness on dengue fever found good in both rural and urban communities but knowledge and preventive practices were considerably low which is predominant in rural. It could be improved through increase community participation and educational campaigns.

A study on knowledge and practices regarding mosquito borne diseases in Rithala village, New Delhi

<p><strong>Background: </strong>Despite various continuous efforts by the government, mosquito borne diseases (MBDs) like dengue and malaria are still a public health problem. Awareness and knowledge about the risk of mosquito bite and source reduction can prevent the transmission of these diseases. The present study was done to assess the awareness of rural population about MBDs and preventive measures against mosquito bite and personal preventive measures (PPMs) taken by them.<strong> </strong>Objective of the study was to assess the knowledge about Mosquito borne diseases and to identify the utilization pattern of personal preventive measures for mosquito control. <strong></strong></p><p><strong>Methods: </strong>A community based cross-sectional study was carried out among adult rural population of Rithala village, New Delhi by systematic random sampling and were interviewed by using semi-structured, pretested and predesigned questionnaire. Data analysis was done by using SPSS version 22.</p><p><strong>Results: </strong>It was observed that 92.21% (188/204) of study participants were aware of mosquito borne diseases and majority were aware of dengue i.e., 87.25% (178/204). The most common source of information about mosquito borne diseases was television 60.78% (124/204). One or the other PPMs were used by 86.76% (177/204) and most commonly used PPMs was liquid vaporizers i.e., 43.13% (88/204).</p><p><strong>Conclusions: </strong>There is a gap between knowledge of MBDs and use of PPMs so there is a need to educate rural population about all MBDs, their different mosquito breeding site and other less common methods of PPMs.</p>