Burden Of Vector-borne Diseases Research Articles

Molecular identification and GC-MS analysis of a newly isolated novel bacterium (Lysinibacillus sp. VCRC B655) for mosquito control.

Mosquitoes are widespread globally and have contributed to transmitting pathogens to humans and the burden of vector-borne diseases. They are effectively controlled at their larval stages by biocontrol agents. Unravelling natural sources for microbial agents can lead us to novel potential candidates for managing mosquito-borne diseases. In the present study, an attempt was made to isolate a novel bacterium from the field-collected agricultural soil for larvicidal activity and promising bacterial metabolites for human healthcare. Field-collected soil samples from the Union territory of Puducherry, India, have been used as the source of bacteria. Isolate VCRC B655 belonging to the genus Lysinibacillus was identified by 16S rRNA gene sequencing and exhibited promising larvicidal activity against different mosquito species, including Culex (Cx.) quinquefasciatus, Anopheles (An.) stephensi, and Aedes (Ae.) aegypti. The lethal concentration (LC) of Lysinibacillus sp. VCRCB655 was observed to be high for Cx. quiquefasciatus: LC50 at 0.047mg/l, LC90 at 0.086mg/l, followed by An. stephensi and Ae. aegypti (LC50: 0.6952mg/l and 0.795mg/l) respectively. Additionally, metabolic profiling of the culture supernatant was carried out through Gas chromatography and Mass spectrophotometry (GC/MS) and identified 15 major secondary metabolites of different metabolic classes. Diketopiperazine (DKPs), notably pyro lo [1, 2-a] pyrazine1, 4-dione, are the abundant compounds reported for antioxidant activity, and an insecticide compound benzeneacetic acid was also identified. A new bacterial isolate, Lysinibacillus sp. VCRC B655 has been identified with significant larvicidal activity against mosquito larvae with no observed in non-target organisms. GC-MS analysis revealed diverse bioactive compounds with substantial biological applications. In conclusion, Lysinibacillus sp. VCRC B655 showed promise as an alternative biocontrol agent for mosquito vector control, with additional biological applications further enhancing its significance.

Assessing the Influence of Climate Change and Environmental Factors on the Top Tick-Borne Diseases in the United States: A Systematic Review.

In the United States (US), tick-borne diseases (TBDs) have more than doubled in the past fifteen years and are a major contributor to the overall burden of vector-borne diseases. The most common TBDs in the US-Lyme disease, rickettsioses (including Rocky Mountain spotted fever), and anaplasmosis-have gradually shifted in recent years, resulting in increased morbidity and mortality. In this systematic review, we examined climate change and other environmental factors that have influenced the epidemiology of these TBDs in the US while highlighting the opportunities for a One Health approach to mitigating their impact. We searched Medline Plus, PUBMED, and Google Scholar for studies focused on these three TBDs in the US from January 2018 to August 2023. Data selection and extraction were completed using Covidence, and the risk of bias was assessed with the ROBINS-I tool. The review included 84 papers covering multiple states across the US. We found that climate, seasonality and temporality, and land use are important environmental factors that impact the epidemiology and patterns of TBDs. The emerging trends, influenced by environmental factors, emphasize the need for region-specific research to aid in the prediction and prevention of TBDs.

Adopting a Statistical, Mechanistic, Integrated Surveillance, Thermal Biology, and Holistic (SMITH) Approach for Arbovirus Control in a Changing Climate: A Review of Evidence

Arbovirus control depends on accurate projections of likely changes in the arthropod vector species, essential to inform local and global public health authorities. According to the WHO Assembly and the Global Vector Control Response (GVCR), by 2030, the burden of vector-borne diseases, particularly arbovirus infections, is expected to be greatly decreased. However, anthropogenic drivers, including climate change, insecticide resistance, and a lack of operational local databases for risk management of emerging and re-emerging arboviruses, hinders effective implementation plans. This article presents a statistical, mechanistic, integrated surveillance, thermal biology, and holistic framework (termed SMITH) to discuss how temperature variations affect the biological transmission, replication, extrinsic incubation period, nutritional behavior, distribution, and survival (TRENDS) of arboviruses. Future transdisciplinary research that involves knowledge translation between local and global communities is required for early detection and risk management of the growing threat posed by arboviruses for human, animal, and planetary health.

Influencing factors among rural households on their awareness level about mosquito borne diseases-a descriptive cross-sectional study from endemic area in Kerala

Background: The global burden of vector borne diseases (VBDs) is 17% of all infectious diseases. Health systems in many tropical and subtropical countries are overwhelmed by outbreaks of dengue, malaria, chikungunya with highest burden among poorest populations. India carries 85% of the global malaria burden. WHO-Global vector control response identified behavioural change need and initiated education to improve public awareness. Malaria, filariasis, chikungunya, JE, dengue is currently endemic in rural Kerala. Main objective of this study was to assess the awareness level in general about the mosquito borne diseases (MBDs) among households from rural field practice areas and to find out its association between influencing factors.Methods: A descriptive cross-sectional study conducted by household survey in 2019 in Perumatty panchayat of rural Kerala. Participants were interviewed separately. The mixed pattern questionnaire consisted of dichotomized and multiple answer questions with scoring and interpretations to assess the awareness level in general. The final outcome was categorized as good, partial and poor awareness and analysed for frequencies and associations.Results: More participants were in 31-45 years age group (39.5%) with mean age 43.5±13.6. Only 7% good, 70% partial and 20% poor awareness levels were found. 32.9% participants had completed secondary school. 43.9% belong to middle class family. 75% participants were aware on ‘mosquito bite’ as mode of transmission. 14.3% aware on all major symptoms. Education, family history, SEC and Knowledge source had significant influence between awareness categories.Conclusions: Low awareness level on MBDs among the rural population needs proper health education interventions.

Modelling the effective reproduction number of vector-borne diseases: the yellow fever outbreak in Luanda, Angola 2015-2016 as an example.

The burden of vector-borne diseases (Dengue, Zika virus, yellow fever, etc.) gradually increased in the past decade across the globe. Mathematical modelling on infectious diseases helps to study the transmission dynamics of the pathogens. Theoretically, the diseases can be controlled and eventually eradicated by maintaining the effective reproduction number, (n}{}{mathcal{R}}_{mathrm{eff}}), strictly less than 1. We established a vector-host compartmental model, and derived (n}{}{mathcal{R}}_{mathrm{eff}}) for vector-borne diseases. The analytic form of the (n}{}{mathcal{R}}_{mathrm{eff}}) was found to be the product of the basic reproduction number and the geometric average of the susceptibilities of the host and vector populations. The (n}{}{mathcal{R}}_{mathrm{eff}}) formula was demonstrated to be consistent with the estimates of the 2015–2016 yellow fever outbreak in Luanda, and distinguished the second minor epidemic wave. For those using the compartmental model to study the vector-borne infectious disease epidemics, we further remark that it is important to be aware of whether one or two generations is considered for the transition “from host to vector to host” in reproduction number calculation.

Wolbachia Population in Vectors and Non-vectors: A Sustainable Approach Towards Dengue Control.

Wolbachia is gram negative obligate endosymbiont known for reproductive manipulation in the host. It is important to study the presence of natural Wolbachia in mosquitoes which can later help in understanding the effect of transfected strain on indigenous strain. With this view, the present study is undertaken to focus on the prevalence, diversity, infection frequencies, phylogeny and density of indigenous Wolbachia strains in wild mosquito species of Odisha. Our study confirms Wolbachia presence in Ae. albopictus, Cx. quinquefasciatus, Cx. vishnui, Cx. gelidus, Ar. subalbatus, Mn. uniformis, and Mn. indiana. Wolbachia in the above mosquitoes were separated into two supergroups (A and B). Ae. albopictus, the major vector of dengue and chikungungunya had both super-infection and mono-infection. The ovaries of Ae. albopictus were highest in density of Wolbachia as compared to midguts or salivary glands. wAlBA and wAlbB density were variable in mosquitoes of F1 generation for both the sex and at different age. We also found that Wolbachia super-infection in females tends to increase whereas wAlbA density reduced completely as compared to wAlbB in males when they grew old. Giemsa stained squashed ovaries revealed pink pleomorphic Wolbachia cells with different shapes and forms. This study is unique in its kind covering the major aspects of the endosymbiont Wolbachia and focusing on its potential as a biocontrol agent in arboviral outbreaks. Knowledge on potential of the indigenous strain and interactions between Wolbachia and viruses can be utilized further to reduce the global burden of vector borne diseases.

Addressing malaria vector control challenges in South Sudan: proposed recommendations

Upon the signing of the Comprehensive Peace Agreement in 2005, the Republic of South Sudan (RSS) has faced a lot of challenges, such as a lack of infrastructure, human resources and an enormous burden of vector borne diseases including malaria. While a national malaria strategic plan 2006-2011 was developed, the vector control component has remained relatively weak. The strategy endorses the distribution of long-lasting insecticidal nets (LLINs) as the frontline intervention with other interventions recommended only when technical and institutional capacity is available. In 2006, a draft integrated vector management (IVM) strategic plan 2007–2012 was developed but never implemented, resulting in minimal coordination, implementation and coverage of malaria vector control tools including their inherent impact. To address this challenge, the vector control team of the National Malaria Control Programme (NMCP) is being strengthened. With the objective of building national capacity and technical collaboration for effective implementation of the IVM strategy, a national malaria vector control conference was held from 15-17th October 2012 in Juba. A range of NMCP partners, state ministries, acadaemia, private sector, national and international non-governmental organizations, including regional and global policymakers attended the meeting. The conference represented a major milestone and made recommendations revolving around the five key elements of the IVM approach. The meeting endorsed that vector control efforts in RSS be augmented with other interventions within the confines of the IVM strategy as a national approach, with strong adherence to its key elements.

Risk Maps:: Transmission and Burden of Vector-borne Diseases

Risk Maps:: Transmission and Burden of Vector-borne Diseases