Diabetes mellitus as a risk factor for severe dengue fever and West Nile fever: A meta-analysis.

BACKGROUND: Dengue fever (DF) and West Nile fever (WNF) have become endemic worldwide in the last two decades. Studies suggest that individuals with diabetes mellitus (DM) are at a higher risk of developing severe complications from these diseases. Identifying the factors associated with a severe clinical presentation is crucial, as prompt treatment is essential to prevent complications and fatalities. This article aims to summarize and assess the published evidence regarding the link between DM and the risk of severe clinical manifestations in cases of DF and WNF. METHODOLOGY/PRINCIPAL FINDINGS: A systematic search was conducted using the PubMed and Web of Science databases. 27 studies (19 on DF, 8 on WNF) involving 342,873 laboratory-confirmed patients were included in the analysis. The analysis showed that a diagnosis of DM was associated with an increased risk for severe clinical presentations of both DF (OR 3.39; 95% CI: 2.46, 4.68) and WNF (OR 2.89; 95% CI: 1.89, 4.41). DM also significantly increased the risk of death from both diseases (DF: OR 1.95; 95% CI: 1.09, 3.52; WNF: OR 1.74; 95% CI: 1.40, 2.17). CONCLUSIONS/SIGNIFICANCE: This study provides strong evidence supporting the association between DM and an increased risk of severe clinical manifestations in cases of DF and WNF. Diabetic individuals in DF or WNF endemic areas should be closely monitored when presenting with febrile symptoms due to their higher susceptibility to severe disease. Early detection and appropriate management strategies are crucial in reducing the morbidity and mortality rates associated with DF and WNF in diabetic patients. Tailored care and targeted public health interventions are needed to address this at-risk population. Further research is required to understand the underlying mechanisms and develop effective preventive and therapeutic approaches.

Examining the paradox: increased malaria risk in children under 5 in female-headed households in Nigeria.

BACKGROUND: Nigeria is facing a severe malaria crisis, accounting for a significant proportion of global cases and deaths of malaria. This study aimed to investigate the differences between female-headed households (FHHs) and male-headed households (MHHs) and their impact on malaria risk among children under five (U5) in Nigeria. METHODS: Data from the 2021 Nigeria Malaria Indicator Survey (NMIS) were used for this cross-sectional study. A representative sample of 10,988 households was analysed, with key variables subjected to frequency calculations, descriptive statistics, and bivariate analyses using t-tests and chi-square analyses to compare the differences between FHHs and MHHs. RESULTS: Among all participants, 92.1% (N = 10,126) reported residing in male-headed households, while 7.8% (N = 862) reported living in female-headed households. MHHs were significantly more likely to own insecticide-treated bed nets (ITNs) than FHHs (64.7% vs. 53.6%, P < 0.001). U5 children in MHHs had a greater likelihood of sleeping under a bed net the night before the survey than U5 children in FHHs (35.3% vs. 30.0%, P < 0.05). The prevalence of fever in the previous two weeks among U5 children was similar in MHHs and FHHs (35.4% vs. 31.4%), and the testing rates for malaria among U5 children who experienced febrile episodes were higher in MHHs than FHHs (22.4% vs. 15.4%, P < 0.05). Although not statistically significant, FHHs exhibited a higher percentage of U5 children testing positive for malaria compared to MHHs (87.8% vs. 78.9%). On the other hand, FHHs had higher education levels, overall wealth index scores, and a larger presence in urban areas compared to MHHs (P < 0.001). Moreover, FHHs reported higher adherence to malaria prevention awareness (P < 0.001). CONCLUSION: In Nigeria, FHHs enjoy relatively better socioeconomic conditions and stronger awareness of malaria prevention compared to their male-headed counterparts. Contrary to expectations, FHHs are at an increased risk of malaria in children under 5 years old. This phenomenon is associated with entrenched gender inequality and the challenges women face in accessing critical assets. As women in FHHs bear the responsibility of income generation while caring for their children, it is crucial to prioritize interventions that address malaria management in FHHs to reduce both malaria incidence and mortality rates.

Recombinant Beauveria bassiana expressing Bacillus thuringiensis toxin Cyt1Aa: a promising approach for enhancing Aedes mosquito control.

The entomopathogenic fungus Beauveria bassiana provides an eco-friendly substitute to chemical insecticides for mosquito control. Nevertheless, its widespread application has been hindered by its comparatively slow efficacy in eliminating mosquitoes. To augment the potency of B. bassiana against Aedes mosquitoes, a novel recombinant strain, Bb-Cyt1Aa, was developed by incorporating the Bacillus thuringiensis toxin gene Cyt1Aa into B. bassiana. The virulence of Bb-Cyt1Aa was evaluated against Aedes aegypti and Aedes albopictus using insect bioassays. Compared to the wild-type (WT) strain, the median lethal time (LT50) for A. aegypti larvae infected with Bb-Cyt1Aa decreased by 33.3% at a concentration of 1 × 108 conidia/mL and by 22.2% at 1 × 107 conidia/mL. The LT50 for A. aegypti adults infected with Bb-Cyt1Aa through conidia ingestion was reduced by 37.5% at 1 × 108 conidia/mL and by 33.3% at 1 × 107 conidia/mL. Likewise, the LT50 for A. aegypti adults infected with Bb-Cyt1Aa through cuticle contact decreased by 33.3% and 30.8% at the same concentrations, respectively. Furthermore, the Bb-Cyt1Aa strain also demonstrated increased toxicity against both larval and adult A. albopictus, when compared to the WT strain. In conclusion, our study demonstrated that the expression of B. thuringiensis toxin Cyt1Aa in B. bassiana enhanced its virulence against Aedes mosquitoes. This suggests that B. bassiana expressing Cyt1Aa has potential value for use in mosquito control. IMPORTANCE: Beauveria bassiana is a naturally occurring fungus that can be utilized as a bioinsecticide against mosquitoes. Cyt1Aa is a delta-endotoxin protein produced by Bacillus thuringiensis that exhibits specific and potent insecticidal activity against mosquitoes. In our study, the expression of this toxin Cyt1Aa in B. bassiana enhances the virulence of B. bassiana against Aedes aegypti and Aedes albopictus, thereby increasing their effectiveness in killing mosquitoes. This novel strain can be used alongside chemical insecticides to reduce dependence on harmful chemicals, thereby minimizing negative impacts on the environment and human health. Additionally, the potential resistance of B. bassiana against mosquitoes in the future could be overcome by acquiring novel combinations of exogenous toxin genes. The presence of B. bassiana that expresses Cyt1Aa is of significant importance in mosquito control as it enhances genetic diversity, creates novel virulent strains, and contributes to the development of safer and more sustainable methods of mosquito control.

A review on Zika vaccine development.

Zika virus (ZIKV), which belongs to the Flavivirus family, is mainly transmitted via the bite of Aedes mosquitoes. In newborns, ZIKV infection can cause severe symptoms such as microcephaly, while in adults, it can lead to Guillain‒Barré syndrome (GBS). Due to the lack of specific therapeutic methods against ZIKV, the development of a safe and effective vaccine is extremely important. Several potential ZIKV vaccines, such as live attenuated, inactivated, nucleic acid, viral vector, and recombinant subunit vaccines, have demonstrated promising outcomes in clinical trials involving human participants. Therefore, in this review, the recent developmental progress, advantages and disadvantages of these five vaccine types are examined, and practical recommendations for future development are provided.

Challenge and opportunity for vector control strategies on key mosquito-borne diseases during the COVID-19 pandemic.

Mosquito-borne diseases are major global health problems that threaten nearly half of the world's population. Conflicting resources and infrastructure required by the coronavirus disease 2019 (COVID-19) global pandemic have resulted in the vector control process being more demanding than ever. Although novel vector control paradigms may have been more applicable and efficacious in these challenging settings, there were virtually no reports of novel strategies being developed or implemented during COVID-19 pandemic. Evidence shows that the COVID-19 pandemic has dramatically impacted the implementation of conventional mosquito vector measures. Varying degrees of disruptions in malaria control and insecticide-treated nets (ITNs) and indoor residual spray (IRS) distributions worldwide from 2020 to 2021 were reported. Control measures such as mosquito net distribution and community education were significantly reduced in sub-Saharan countries. The COVID-19 pandemic has provided an opportunity for innovative vector control technologies currently being developed. Releasing sterile or lethal gene-carrying male mosquitoes and novel biopesticides may have advantages that are not matched by traditional vector measures in the current context. Here, we review the effects of COVID-19 pandemic on current vector control measures from 2020 to 2021 and discuss the future direction of vector control, taking into account probable evolving conditions of the COVID-19 pandemic.

The sex pheromone heptacosane enhances the mating competitiveness of sterile Aedes aegypti males.

BACKGROUND: Aedes aegypti is a vector that transmits various viral diseases, including dengue and Zika. The radiation-based sterile insect technique (SIT) has a limited effect on mosquito control because of the difficulty in irradiating males without reducing their mating competitiveness. In this study, the insect sex pheromone heptacosane was applied to Ae. aegypti males to investigate whether it could enhance the mating competitiveness of irradiated males. METHODS: Heptacosane was smeared on the abdomens of Ae. aegypti males that were allowed to mate with untreated virgin females. The insemination rate was used to assess the attractiveness of heptacosane-treated males to females. The pupae were irradiated with different doses of X-rays and γ-rays, and the emergence, survival time, egg number, and hatch rate were detected to find the optimal dose of X-ray and γ-ray radiation. The males irradiated at the optimal dose were smeared with heptacosane, released in different ratios with untreated males, and mated with females. The effect of heptacosane on the mating competitiveness of irradiated mosquitoes was then evaluated by the hatch rate, induced sterility, and mating competitiveness index. RESULTS: Applying heptacosane to Ae. aegypti males significantly increased the insemination rate of females by 20%. Pupal radiation did not affect egg number but significantly reduced survival time and hatch rate. The emergence of the pupae was not affected by X-ray radiation but was affected by γ-ray radiation. Pupae exposed to 60 Gy X-rays and 40 Gy γ-rays were selected for subsequent experiments. After 60 Gy X-ray irradiation or 40 Gy γ-ray irradiation, the average hatch rate was less than 0.1%, and the average survival time was more than 15 days. Moreover, at the same release ratio, the hatch rate of the irradiated group perfumed with heptacosane was lower than that of the group without heptacosane. Conversely, the male sterility and male mating competitiveness index were significantly increased due to the use of heptacosane. CONCLUSIONS: The sex pheromone heptacosane enhanced the interaction between Ae. aegypti males and females. Perfuming males irradiated by X-rays or γ-rays with heptacosane led to a significant increase in mating competitiveness. This study provided a new idea for improving the application effect of SIT.

Sterility of Aedes albopictus by X-ray Irradiation as an Alternative to γ-ray Irradiation for the Sterile Insect Technique.

The mosquito Aedes albopictus can transmit various arboviral diseases, posing a severe threat to human health. As an environmentally friendly method, sterile insect technology (SIT) is considered an alternative to traditional methods such as chemical pesticides to control Ae. albopictus. In SIT, the sterility of male mosquitoes can be achieved by γ-ray or X-ray radiation. Compared with γ-rays, X-rays are easier to obtain, cheaper, and less harmful. However, there is a lack of comparative assessment of these two types of radiation for SIT under the same controlled conditions. Here, we compared the effects of X-ray and γ-ray radiation on the sterility of Ae. albopictus males under laboratory-controlled conditions. Neither type of radiation affected the number of eggs but significantly reduced the survival time and hatch rate. The same dose of γ-rays caused a higher sterility effect on males than X-rays but had a more significant impact on survival. However, X-rays could achieve the same sterility effect as γ-rays by increasing the radiation dose. For example, X-rays of 60 Gy induced 99% sterility, similar to γ-rays of 40 Gy. In the test of male mating competitiveness, the induced sterility and the male mating competitiveness index were also identical at the same release ratio (sterile males/fertile males). At a release ratio of 7:1, nearly 80% of eggs failed to hatch. Sterile males produced by X-ray and γ-ray radiation had similar male competitiveness in competition with field males. In conclusion, a higher dose of X-rays is required to achieve the same sterility effect, compared to γ-rays. When γ-rays are not readily available, high-dose X-rays can be used instead. This study provides data supporting the selection of more suitable radiation for the field release of sterile male mosquitoes.