Insecticide resistant Aedes populations have recently been reported in Pakistan, imposing a threat to their control. We aimed to evaluate the susceptibility of Aedes aegypti and Aedes albopictus populations from Lahore to WHO-recommended insecticides and to investigate metabolic and target-site resistance mechanisms. For this purpose, we first carried out bioassays with the larvicides temephos and pyriproxyfen, and the adulticides malathion, permethrin, deltamethrin, alpha-cypermethrin, and etofenprox. We looked for Knockdown resistance mutations (kdr) by qPCR, High-Resolution Melt (HRM), and sequencing. In order to explore the role of detoxifying enzymes in resistance, we carried out synergist bioassay with both species and then checked the expression of CYP9M6, CYP9J10, CYP9J28, CYP6BB2, CCAe3a, and SAP2 genes in Ae. aegypti. Both species were susceptible to organophosphates and the insect growth regulator, however resistant to all pyrethroids. We are reporting the kdr haplotypes 1520Ile + 1534Cys and T1520 + 1534Cys in high frequencies in Ae. aegypti while Ae. albopictus only exhibited the alteration L882M. PBO increased the sensitivity to permethrin in Ae. aegypti, suggesting the participation of P450 genes in conferring resistance, and indeed, CYP928 was highly expressed. We presume that dengue vectors in Lahore city are resistant to pyrethroids, probably due to multiple mechanisms, such as kdr mutations and P450 overexpression.

Vector control largely relies on neurotoxic chemicals, and insecticide resistance (IR) directly threatens their effectiveness. In some cases, specific alleles cause IR, and knowledge of the genetic diversity and gene flow among mosquito populations is crucial to track their arrival, rise, and spread. Here we evaluatedAedes aegyptipopulations’ susceptibility status, collected in 2016 from six different municipalities of Rio de Janeiro state (RJ), to temephos, pyriproxyfen, malathion, and deltamethrin. We collected eggs ofAe.aegyptiin Campos dos Goytacazes (Cgy), Itaperuna (Ipn), Iguaba Grande (Igg), Itaboraí (Ibr), Mangaratiba (Mgr), and Vassouras (Vsr). We followed the World Health Organization (WHO) guidelines and investigated the degree of susceptibility/resistance of mosquitoes to these insecticides. We used the Rockefeller strain as a susceptible positive control. We genotyped the V1016I and F1534C knockdown resistance (kdr) alleles using qPCR TaqMan SNP genotyping assay. Besides, with the use ofAe.aegyptiSNP-chip, we performed genomic population analyses by genotyping more than 15,000 biallelic SNPs in mosquitoes from each population. We added previous data from populations from other countries to evaluate the ancestry of RJ populations.All RJAe.aegyptipopulations were susceptible to pyriproxyfen and malathion and highly resistant to deltamethrin. The resistance ratios for temephos was below 3,0 in Cgy, Ibr, and Igg populations, representing the lowest rates since IR monitoring started in this Brazilian region. We found thekdralleles in high frequencies in all populations, partially justifying the observed resistance to pyrethroid. Population genetics analysis showed thatAe.aegyptirevealed potential higher migration among some RJ localities and low genetic structure for most of them. Future population genetic studies, together with IR data inAe aegyption a broader scale, can help us predict the gene flow within and among the Brazilian States, allowing us to track the dynamics of arrival and changes in the frequency of IR alleles, and providing critical information to improving vector control program.

The mosquito Aedes aegypti is distributed worldwide and is recognized as the primary vector for dengue in numerous countries. To investigate whether the fitness cost of a single DENV-1 isolate varies among populations, we selected four Ae. aegypti populations from distinct localities: Australia (AUS), Brazil (BRA), Pakistan (PAK), and Peru (PER). Utilizing simple methodologies, we concurrently assessed survival rates and fecundity. Overall, DENV-1 infection led to a significant decrease in mosquito survival rates, with the exception of the PER population. Furthermore, infected Ae. aegypti from PAK, the population with the lowest infection rate among those tested, exhibited a noteworthy reduction in egg laying. These findings collectively suggest that local mosquito-virus adaptations may influence dengue transmission in endemic settings.

In this review, the disease and immunogenicity affected by COVID-19 vaccination at the metabolic level are described considering the use of nuclear magnetic resonance (NMR) spectroscopy for the analysis of different biological samples. Consistently, we explain how different biomarkers can be examined in the saliva, blood plasma/serum, bronchoalveolar-lavage fluid (BALF), semen, feces, urine, cerebrospinal fluid (CSF) and breast milk. For example, the proposed approach for the given samples can allow one to detect molecular biomarkers that can be relevant to disease and/or vaccine interference in a system metabolome. The analysis of the given biomaterials by NMR often produces complex chemical data which can be elucidated by multivariate statistical tools, such as PCA and PLS-DA/OPLS-DA methods. Moreover, this approach may aid to improve strategies that can be helpful in disease control and treatment management in the future.

Background: Yellow fever (YF) is an acute hemorrhagic disease endemic to Africa and Latin America; however, no cases have been reported in Asian regions with high Aedes aegypti infestation. Factors such as environmental conditions and genetic variations in the yellow fever virus (YFV) strains and mosquito populations may explain this absence. Mosquito populations have undergone strong selective pressure owing to the excessive use of insecticides. This pressure has led to the spread of alterations, such as knockdown-resistant mutations (kdr), which, while conferring resistance to pyrethroids, also induce various physiological side effects in the insect. Therefore, it is important to investigate whether the presence of kdr mutations influences the infectivity of YFV mosquitoes. This study evaluated the susceptibility of Ae. aegypti from Pakistan with distinct kdr genotypes to different YFV strains under laboratory conditions. Methods: Ae. aegypti from a Pakistani colony were exposed to YFV strains (PR4408/2008 and ES504/2017) along with the Rockefeller strain. After 14 days, RNA and DNA were extracted for viral RNA detection (qPCR) and kdr genotyping (TaqMan qPCR and HRM for T1520I and F1534C SNPs). Results: Pakistani Ae. aegypti were orally susceptible to YFV, with infection rates of 83.7% (PR4408/2008) and 61.3% (ES504), respectively, similar to Rockefeller. Two kdr genotypes (II + CC and TI + FC) were identified, with no significant differences in viral infection or dissemination rates. Conclusions: The Ae. aegypti population from Asia is capable of YFV infection and dissemination, regardless of kdr genotype.

In this chapter, we will try to explore the gaps and limitations in vector control interventions. The spectrum of vector-borne diseases is spreading to Europe and North America. Conventional vector control methods are losing their efficacy due to several factors, like global warming, the development of insecticide resistance, unplanned urbanization, and exponential population increase. Several countries are investing in novel vector control strategies along with conventional methods. Conventional control strategies can be made efficient by proper planning and management, as new strategies will take time to be operational. Paratransgenic methods like Wolbachia have shown promising results, along with other population replacement and population suppression techniques. But these methods cannot stop the spread of insect vectors beyond their native range. Among growing concerns hindering vector control, lack of coordination between vector control programs, over-reliance on neurotoxic insecticides, lack of public health education, lack of involvement of important sectors of society, security risks, similar control interventions against different target species, lack of skills of health workers, inadequate duration of a specific control intervention, and lack of political will are important. To effectively control the spread of vector-borne diseases, we should address these issues. Other strategies, like vaccine and drug development along with the One Health approach, are very important. We conclude that conventional control interventions, participation of all sectors of society, effective and prompt communication between stakeholders, and incorporating them into an integrated vector management approach are the only way forward in vector control.