Control Of Vector-borne Diseases Research Articles

The chaperone BiP promotes dengue virus replication and mosquito vitellogenesis in Aedes aegypti

Binding immunoglobulin protein (BiP, also known as GRP78), a chaperone and master regulator of the unfolded protein response (UPR) pathway, plays an essential role in several flavivirus infections, but its functional role in regulating dengue virus replication in the mosquito remains largely unknown. We here demonstrated the interaction between a dengue virus serotype 2 (DENV2) and BiP in Aedes aegypti and report the discovery of a novel functional role of BiP in mosquito vitellogenesis. Silencing Ae. aegypti BiP (AaBiP) expression resulted in the significant inhibition of DENV2 viral genome replication, viral protein production, and infectious viral particle biogenesis. Co-immunoprecipitation assays showed that the DENV2 non-structural protein 1 (NS1) interacts with the AaBiP protein, and silencing AaBiP expression led to enhanced DENV2 NS1 aggregation, indicating that AaBiP plays a role in viral protein stability. A kinetic study focusing on pulse treatment of MG132, a proteasome inhibitor, in AaBiP-silenced mosquitoes showed that DENV2 NS1 was drastically elevated, which further suggests that AaBiP-mediated viral protein degradation is mediated by proteasomal machinery. Silencing of AaBiP also resulted in a reduction in mosquito fertility and fecundity. Depletion of AaBiP inhibited mosquito vitellogenesis due to the reduction of vitellogenin mRNA and elevated aggregation of vitellogenin protein post blood meal, further suppressing ovary development and fecundity. Overall, our results suggest that AaBiP is a dual-function protein with roles in both the regulation of dengue virus replication and mosquito reproduction. Our findings will be useful in the establishment of more efficient strategies for vector-borne disease control.

Integrated vector management program in the framework of the COVID-19 pandemic in Medellin, Colombia

Introduction: The COVID-19 pandemic pressured health care systems to remain alert and active in their vector-borne disease control and prevention programs, leading to changes in vector control strategies in urban areas affected by dengue, Zika and chikungunya. Objective: To describe the adaptations made to the vector control and surveillance program in Medellín during the COVID-19 health emergency. Materials and methods: Once the health emergency started, biosecurity protocols were developed. Entomological surveillance was strengthened from the institutional environment instead of homes. Data was collected in Medellín from 2018 to 2021 during the vector control and surveillance program activities, which included epidemiological and entomovirological surveillance, entomological index survey, ovitrap monitoring, community mobilization, search and elimination of mosquito breading sites, and chemical control. These actions were adapted and/or increased to promote self-care among communities in total and partial confinement, and to develop prevention and control measures. Results: Mosquito monitoring was increased by 40% using ovitraps, entomological virological surveillance showed an increase in 2020 of 34,4% compared to 2019 and virtual media was used to keep and improve contact with the community. Conclusion: The COVID-19 pandemic had a significant impact on arbovirus prevention and control programs. The city of Medellín quickly adapted its entomo-virological surveillance activities, control measures, and the contact with the community during the pandemic, which allow the Integrated Vector Management program to remain active in the city.

Biotoxicity comparison of Bacillus thuringiensis to control vector borne diseases against mosquito fauna

The current study was designed to evaluate the biotoxicity of screened echo-friendly Bacillus thuringiensis strains from different areas of Pakistan. Out of 50 samples, 36% Bt. isolates were quarantined from soil containing cattle waste after morphological, biochemical, and molecular characterization. The toxicity bioassays with Bt. spores and protein diet proved that 11 Bt. isolates were utmost noxious to 3rd instar larvae of mosquitoes Aedes aegypti, Anopheles stephensi, and Culex pipiens. The entopathogenic activity of first 4 Bt. toxins against A. aegypti was highly lethal as compared to the other dipteran larvae. The toxicity (LC50) of spore diet of Bt. strains GCU-DAB-NF4 (442.730 ± 0.38 μg/ml), NF6 (460.845 ± 0.29 μg/ml), NF3 (470.129 ± 0.28 μg/ml), and NF7 (493.637 ± 0.70 μg/ml) was quite high against A. aegypti as compared to the C. pipiens after 24 h of incubation. The highest toxicity of total cell protein was shown by GCU-DAB-NF4 (LC50 = 84.10 ± 50 μg/ml), NF6 (95.122 ± 0.40 μg/ml), NF3 (100.715 ± 06 μg/ml), and NF5 (103.40 ± 07 μg/ml) against A. aegypti after 24 h. So, these strains a have great potential to be used as biological control especially against A. aegypti as compared to the C. pipiens.

Resistance to Pyrethroids in the Malaria Vector Anopheles albimanus in Two Important Villages in the Soconusco Region of Chiapas, Mexico, 2022.

Chiapas State comprises the largest malaria foci from Mexico, and 57% of the autochthonous cases in 2021, all with Plasmodium vivax infections, were reported in this State. Southern Chiapas is at constant risk of cases imported due to migratory human flow. Since chemical control of vector mosquitoes is the main entomological action implemented for the prevention and control of vector-borne diseases, this work aimed to investigate the susceptibility of Anopheles albimanus to insecticides. To this end, mosquitoes were collected in cattle in two villages in southern Chiapas in July-August 2022. Two methods were used to evaluate the susceptibility: the WHO tube bioassay and the CDC bottle bioassay. For the latter, diagnostic concentrations were calculated. The enzymatic resistance mechanisms were also analyzed. CDC diagnostic concentrations were obtained; 0.7 μg/mL deltamethrin, 12 μg/mL permethrin, 14.4 μg/mL malathion, and 2 μg/mL chlorpyrifos. Mosquitoes from Cosalapa and La Victoria were susceptible to organophosphates and to bendiocarb, but resistant to pyrethroids, with mortalities between 89% and 70% (WHO), and 88% and 78% (CDC), for deltamethrin and permethrin, respectively. High esterase levels are suggested as the resistance mechanism involved in the metabolism of pyrethroids in mosquitoes from both villages. Mosquitoes from La Victoria might also involve cytochrome P450. Therefore, organophosphates and carbamates are suggested to currently control An. albimanus. Its use might reduce the frequency of resistance genes to pyrethroids and vector abundance and may impede the transmission of malaria parasites.

A Scoping Review of Mathematical Models Used to Investigate the Role of Dogs in Chagas Disease Transmission.

Chagas disease is a zoonotic vector-borne disease caused by the parasite Trypanosoma cruzi, which affects a variety of mammalian species across the Americas, including humans and dogs. Mathematical modeling has been widely used to investigate the transmission dynamics and control of vector-borne diseases. We performed a scoping review of mathematical models that investigated the role of dogs in T. cruzi transmission. We identified ten peer-reviewed papers that have explicitly modeled the role of dogs in Chagas transmission dynamics. We discuss the different methods employed in these studies, the different transmission metrics, disease transmission routes, and disease control strategies that have been considered and evaluated. In general, mathematical modeling studies have shown that dogs are not only at high risk of T. cruzi infection but are also major contributors to T. cruzi transmission to humans. Moreover, eliminating infected dogs from households or frequent use of insecticide was shown to be effective for curtailing T. cruzi transmission in both humans and dogs. However, when insecticide spraying is discontinued, T. cruzi infections in dogs were shown to return to their pre-spraying levels. We discuss the challenges and opportunities for future modeling studies to improve our understanding of Chagas disease transmission dynamics and control.

Rickettsia felis is an emerging human pathogen associated with cat fleas: A review of findings in Taiwan

Rickettsia felis is an emerging rickettsial agent principally associated with cat fleas (Ctenocephalides felis), formerly discovered in 1990. Since then, clinical cases of R. felis infection have been identified globally by specific DNA sequences in patients with undifferentiated febrile illness, including in Taiwan, but such evidence is limited. R. felis rickettsiosis is self-limiting and easily treated with doxycycline, but its diagnosis remains a challenge. Environmental risk factors for R. felis rickettsiosis have yet to be clearly demonstrated, and its transmission biology is incompletely understood. Cat fleas are naturally infected with R. felis at varying rates, and vector competence in the transmission of R. felis has been demonstrated in animal models, including dogs, which may serve as reservoir hosts. In northern Taiwan, despite ∼20% of cat fleas infesting companion animals consistently found to be infected with R. felis, only a few cases of potential R. felis infection have been identified through a retrospective serological investigation, though without molecular confirmation. Ecological studies have identified divergent R. felis-like organisms in different arthropod hosts, but these strains appear to serve as nonpathogenic endosymbionts. Although its association with disease is limited, we believe cat flea-borne R. felis warrants increased recognition in an aging population due to immunosenescence and the proximity of companion animals to the elderly. Adopting a One Health approach involving collaboration and communication between clinicians, veterinarians, public health practitioners, and environmental scientists will improve our knowledge about this neglected pathogen and promote the prevention and control of vector-borne diseases.

Dengue outbreak update in India: 2022.

Dengue is an emerging illness in India, where it is endemic in some areas and sometimes causes yearly epidemics. Each dengue outbreak starts with high death and morbidity, which has a significant socioeconomic impact. As of September 30, 2022, India had 63,280 dengue cases, according to information provided by the National Centre for Vector Borne Diseases Control. North India is most severely impacted by each outbreak. In Uttar Pradesh, the state with the most population in India, there have been 2060 confirmed cases of dengue and 1 mortality till September 2022 reported. Patients are being reported from semi-urban, rural, and urban areas. It is essential to properly monitor disease cases through disease surveillance in order to ensure prompt case management if dengue outbreak control is to be achieved. An efficient diagnostic approach for early diagnosis is urgently required to reduce the severity of the sickness, the length of the hospital stay, and clinical consequences.

Management of Insect Borne Human Diseases – A Case Study on Novel Bio-Larvicide for Mosquito Borne Diseases Including Dengue

In India National Vector Borne Diseases Control programme is an umbrella organization for management and control of six out of eight insect-borne human diseases, viz., Malaria, Lymphatic Filariasis (LF), Kala-azar, Dengue/ Chikungunya, and Japanese Encephalitis. Of these, India is committed for elimination of the first three diseases from the country. 8.6% of India’s total population belongs to tribal community yet contribute 21% of Plasmodium falciparum infection and 29% of malaria-related deaths. There is an urgent need to implement novel strategies to overcome insecticide resistance in Anopheles culicifacies that transmit 60-70% of malaria cases in India. One such strategy is to use Chilodonella uncinata, an indigenous, maternally transmitted, facultative protozoan bio-larvicide with many biological control properties against mosquito vectors. In view of the above, if India really aims to achieve malaria elimination by 2030, there is an urgent need that tribal regions are given more attention.

Tracking district-level performance in the context of achieving zero indigenous case status by 2027.

India has committed to zero indigenous malaria cases by 2027 and elimination by 2030. Of 28 states and 8 union territories of India, eleven states were targeted to reach the elimination phase by 2020. However, state-level epidemiology indicates that several states of India may not be on the optimum track, and few goals set in National Framework for Malaria Elimination (NFME) for 2020 remain to be addressed. Therefore, tracking the current progress of malaria elimination in India at the district level, and identifying districts that are off track is important in understanding possible shortfalls to malaria elimination. Annual malaria case data from 2017-20 of 686 districts of India were obtained from the National Center for Vector-Borne Diseases Control (NCVBDC) and analysed to evaluate the performance of districts to achieve zero case status by 2027. A district's performance was evaluated by calculating the annual percentage change in the total number of malaria cases for the years 2018, 2019 and 2020 considering the previous year as a base year. The mean, median and maximum of these annual changes were then used to project the number of malaria cases in 2027. Based on these, districts were classified into four groups: 1) districts that are expected to reach zero case status by 2027, 2) districts that would achieve zero case status between 2028 and 2030, 3) districts that would arrive at zero case status after 2030, and 4) districts where malaria cases are on the rise. Analysis suggest, a cohort of fifteen districts require urgent modification or improvement in their malaria control strategies by identifying foci of infection and customizing interventions. They may also require new interventional tools that are being developed recently so that malaria case reduction over the years may be increased.

Occurrence of Some Mosquito Species in Tha-Ma-Nya Village, Hpa-an Township, Kayin State in Myanmar

Among the numerous species of blood-sucking insects, mosquitoes stand out as most offensive to man and other warm-blooded animals. Mosquitoes were collected by indoor and outdoor CDC light traps in randomly selected household and larvae were collected in and around 3 Kilo meter radius from the study site. A total of 14 species, five genera under family Culicidae were recorded in Tha-ma-nya village. Recorded species included two species under genus Aedes, three species under genus Culex one species under the genus Armigeres, one species under the genus Toxorhynchities and 7 species under genus Anopheles. Species inentification was done according to different morphological keys. Altogether seven out of 14 recorded mosquito species were medically important vector species. Aedes aegypti and Ae. albopictus were primary and secondary vectors of dengue fever. Culex quinquefasciatus is a microfilariasis vector. The important vectors of Japanese encephalitis are Culex tritaeniorhynchus and Culex gelidus. High density of malaria vector Anopheles dirus was collected in outdoor light trap than An. minimus, although An. minimus was collected high density by indoor CDC light traps. Virus of Japanese encephalitis could transmit from rearing pig and ducks to persons living in the study area. Indoor clear water containers serve as the favorable places for living Aedes spp. Outdoor water storage concrete tanks provided stagnant water to breed Culex and Anopheles species. Water pools, rock pools and rice fields water were found high preferences for breeding of malaria vectors An. dirus and An. minimus larvae and An. dirus larvae was also collected from concrete tanks. Microfilariasis vector Cx. quinquefqsciatus and JE vector Cx. tritaeniorhynchus larvae were collected from polluted water pools and Dengue vector larvae as Aedes larvae were collected from metal drums, bago jars and concrete tanks. Status of the mosquito species composition in the Tha-ma-nya village provided database not only for further researches but also for giving good knowledge and practice in health workers for effective control of vector borne diseases.

Strategies and Advancements for Control of Vector Borne Diseases of Public Health Concern

Strategies and Advancements for Control of Vector Borne Diseases of Public Health Concern

A Study of Malaria in West Bengal

Background: Malaria still occurs in West Bengal which is one of the states in the eastern part of India. Materials and Methods: The study design included an analysis of the 2017 and 2018 annual reports of the National Centre for Vector Borne Disease Control (NCVBDC). Results: The district of Kolkata had a high Annual Parasite Incidence (API) of Malaria of 3.72 during 2017 which decreased to 3.12 in 2018. Conclusion: If interventions such as the treatment of asymptomatic carriers take place, it is expected that the API will come down sooner in Kolkata district and in the rest of the state too.

Linkages between malaria and malnutrition in co-endemic regions of India

IntroductionMalaria and malnutrition are key public health challenges in India. However, the relationship between them is poorly understood. Here, we aimed to elucidate the potential interactions between the two health...

Coverage of mass drug administration (MDA) and operational issues in elimination of lymphatic filariasis in selected districts of Jharkhand, India.

Despite annual rounds of mass drug administration (MDA) being carried out every year since 2004 to break the transmission of lymphatic filariasis, India has not achieved elimination status in many areas of country. This study was conducted to determine the operational issues in the implementation of MDA for elimination of lymphatic filariasis in selected districts of Jharkhand. Two districts of Jharkhand state were selected for present cross-sectional study. Multi-staged cluster sampling was adopted to select study participants. Data were collected with use of prescribed questionnaire of National Vector Borne Disease Control Programme (NVBDCP) from the study participants. Data related to socio-demographic details, coverage and compliance of MDA and operational issues were collected. Findings of independent assessment show that percentage of MDA coverage and compliance for Hazaribag district was 96.02% and 88.90%, respectively. On the other hand, percentage of MDA coverage and compliance was found to be only 67.06% and 48.44% in Chatra district. Overall drug consumption was significantly associated with age group (p-value = 0.045), educational status (p-value = <0.0001) and socio-economic status (p-value <0.0001) of eligible population. Most common reason for not swallowing the drugs was found to be absence of family members at the time of MDA rounds followed by no visit of house by drug distributors. Coverage and compliance of MDA was better in Hazaribag district as compared to Chatra district. In order to increase compliance, socio-demographic factors must also be addressed apart from other operational issues.

A study to assess knowledge of primary health workers on malaria epidemiology, diagnosis, and treatment in Patiala district, India

Background: India accounts for (4%) of all malaria cases worldwide. The World malaria report 2017 showed that, by 2016, global progress against malaria had stalled and was off track to meet the Global Technical Strategy milestones for 2020. Aims and Objectives: The aim of the study is to assess knowledge of rural medical officers (RMO) and health workers on malaria epidemiology, diagnosis, and treatment as per National Vector Borne Disease Control Program of India guidelines. Materials and methods: A descriptive, observational, and cross-sectional study was done among government health personnel’s using a semi-structured questionnaire. Results: In the present study, 258 health personnel’s participated comprising multipurpose health workers female (MPHW-F), multipurpose health worker male (MPHW-M), and RMO. The standardized score on knowledge of vector biology and epidemiology was 72% and 54% for RMO and (MPHW-M), respectively. On malaria diagnosis, MPHW-M has got median score (53%) as compared to RMO (46%). On national malaria drug policy, there is a marginal difference between median score of RMO (42%) and MPHW-M (40%). Overall, there is incomplete and poor knowledge of treatment of malaria among all health personnel’s with lack of concept about presumptive treatment. Training showed some positive impact on the knowledge of MPHW-F but no impact on MPHW-M. Graduates and experienced workers have got better knowledge than undergraduates and MPHW-M have more knowledge than MPHW-F. There is poor knowledge of reporting formats, and usage of rapid diagnostic kits among all the health personnels. There was no significant impact of education qualification, in service training and work experience on the knowledge of Male health workers. Conclusion: Training needs to be suitably tailored as there is a lot of scope of improvement in the knowledge regarding malaria diagnosis and treatment among health workers.

The need to implement one health approach in controlling vector-borne diseases in Nigeria

Introduction. The primary goal of this article is to raise attentiveness about the critical need for vector-borne disease control in Nigeria in relation to One Health, as well as to examine existing understanding on this subject matter, which is quickly befitting as a valuable resource for public health policymakers and specialists across the country. Globally, there has been an increase in the number of vectors, which has resulted in an increase in vector-borne diseases. Thousands of individuals die every year as a consequence of vector-borne diseases, and there is an urgent need to manage these vectors.&#x0D; Material and methods. The present research used PubMed, ResearchGate, WHO and other online databases with the following keywords “Climate change in Nigeria”, “Public health in Nigeria”, “Vector-borne Diseases”, “Nigeria population” and “One Health in Nigeria”.&#x0D; Results. We observed that there has not been an implementation of the One Health approach against Vector-borne diseases in Nigeria.&#x0D; Conclusions. The One Health strategy has the potential to address this issue. One Health is the concept that the health of human is intertwined with that of animals and our collective environment. Malaria is a vector-borne disease that is one of Nigeria's biggest health issues. However, land use changes such as deforestation, mining, and other activities have increased in Nigeria, while climate changes have increased internationally.

MALARIA PARASITE STATUS IN THE STATE OF UTTAR PRADESH BETWEEN 2018 AND 2022

Background: To the best knowledge of the author, there is no report on the current status of Malaria in the state of Uttar Pradesh, India. This study is an attempt in that direction.&#x0D; Materials and Methods: The study design included an analysis of the 2017 and 2018 annual reports as well as the website of the of the National Centre for Vector-Borne Diseases Control (NCVBDC).&#x0D; Results: Bareilly District in Uttar Pradesh had a low Annual Parasite Incidence (API) of Malaria of 0.06 in 2017 which increased to 7.32 in 2018.&#x0D; Conclusions: If interventions like the treatment of asymptomatic carriers take place, it is expected that the API in this district and the entire state will come down quickly.

Education and Socio-economic status are key factors influencing use of insecticides and malaria knowledge in rural farmers in Southern Côte d’Ivoire

BackgroundInsecticides play a key role in rural farming; however, their over- or misuse has been linked with a negative impact on malaria vector control policies. This study was conducted amongst agricultural communities in Southern Côte d’Ivoire to identify which insecticides are used by local farmers and how it relates to the perception of farmers on malaria. Understanding the use of insecticides may help in designing awareness programme on mosquito control and pesticides management.MethodsA questionnaire was administered to 1399 farming households across ten villages. Farmers were interviewed on their education, farming practices (e.g. crops cultivated, insecticides use), perception of malaria, and the different domestic strategies of mosquito control they use. Based on some pre-defined household assets, the socioeconomic status (SES) of each household was estimated. Statistical associations were calculated between different variables, showing significant risk factors.ResultsThe educational level of farmers was significantly associated with their SES (p < 0.0001). Most of the householders (88.82%) identified mosquitoes as the principal cause of malaria, with good knowledge of malaria resulting as positively related to high educational level (OR = 2.04; 95%CI: 1.35, 3.10). The use of indoor chemical compounds was strongly associated to the SES of the households, their education level, their use of ITNs and insecticide in agricultural (p < 0.0001). Indoor application of pyrethroid insecticides was found to be widespread among farmers as well as the use of such insecticide for crops protection.ConclusionOur study shows that the education level remains the key factor influencing the use of insecticides by farmers and their awareness of malaria control. We suggest that better communication tailored to education level and including SES, controlled availability and access to chemical products, should be considered when designing campaigns on use of pesticides and vector borne disease control for local communities.

Importance of proper nutrition in dengue infections

Dengue fever has become one of the most significant public health issues in tropical and subtropical countries, including India. Most of the states in India report dengue fever cases during and after the moon soon each year. The affected patients have been at their homes for 4-5 days, either from fever or acute signs of dehydration, low platelets, vomiting, abdominal pain, and fever. Some of these seriously ill patients are admitted to the hospital for IV fluids, hydration, and monitoring of their vital signs. Overall, this brief review is based on data from the World Health Organization, the National Center for Vector Borne Disease Control (NCVBDC, govt. of India), and other relevant portals searched by relevant keywords. This paper’s primary goal is to present and review home-based, low-cost nutrition integrated care for dengue After reviewing the data, the study showed the recent three years of dengue status in all the states of India.Using a mosquito net, paracetamol as a fever-reducing drug, and the best food through a maximum liquid diet are already proven preventive measures against infectionsIn addition to extra water cum electrolyte drinks, all macro and micronutrients are essential proportionally for managing platelet count and boosting immunity against the virus. Sufficient and complete data is needed to do more research in community health and therapeutic nutrition.

Artificial intelligence (AI): a new window to revamp the vector-borne disease control.

Artificial intelligence (AI) facilitates scientists to devise intelligent machines that work and behave like humans to resolve difficulties and problems by utilizing minimal resources. The Healthcare sector has benefited due to this. Mosquito-transmitted diseases pose a significant health risk. Despite all advances, present strategies for curbing these diseases still depend largely on controlling the mosquito vectors. This strategy demands an army of entomology experts for thorough monitoring, determining, and finally eradicating the targeted mosquito population. Deep learning (DL) algorithms may substitute such unmanageable processes. The current review focuses on how AI, with particular emphasis on deep learning, demonstrates effectiveness in quick detection, identification, monitoring, and finally controlling the target mosquito populations with minimal resources. It accelerates the pace of operation and data exploration on ongoing evolutionary status, tendency to feed blood, and age grading of mosquitoes. The successful combination of computer and biological sciences will provide practical insight and generate a new research niche in this study area.