Journal of Arthropod-Borne Diseases

Impact of Omics Studies on Understanding Insecticide Resistance Mechanisms in Sub-Saharan Malaria Vectors: A Systematic Review

Yetunde Grace Orogun — 2025-12-06

Background: Malaria remains a major global health challenge, disproportionately affecting sub-Saharan Africa. The growing threat of resistance to insecticides in Anopheles vector populations poses a major challenge to the efficacy of core interventions such as long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS). This systematic review aimed to evaluate the contribution of omics approaches, particularly genomics, transcriptomics, and multi-omics, to understanding the resistance mechanisms in malaria vectors in sub-Saharan Africa and their impact on current and future vector control strategies.
Methods: A comprehensive search was conducted using PubMed, Web of Science, and Google Scholar for eligible studies published between January 2016 and April 2025. Studies using at least one omics approach to investigate resistance in Anopheles species were included. We extracted and analyzed data on study location, vector species, omics methods, insecticide classes, resistance mechanisms, and key findings according to PRISMA guidelines.
Results: Twenty-two studies met the inclusion criteria. Genomic and transcriptomic approaches revealed key resistance mechanisms, notably involving metabolic resistance, target-site mutations, and cuticular changes. Multi-omics studies uncovered novel resistance markers such as CYP450 reductase (CPR), UDP-glycosyltransferases (UGTs), and salivary gland proteins. Multi-country collaborations were common, reflecting the cross-border nature of insecticide resistance, while species-specific responses highlighted localized adaptation.
Conclusion: Omics studies have significantly enhanced the understanding of resistance to insecticides among malaria vectors, offering valuable insights for molecular diagnostics and region-specific vector control. Integrating these approaches into routine surveillance is crucial to inform sustainable malaria control and elimination strategies.

The Association between Demodex Infestation and Hair Loss Severity in a Referred Patient Population

Abozar Nasiri-Jahrodi — 2025-12-13

Background: Hair follicle mites of the genus Demodex (Prostigmata: Demodicidae) are the most common external obligate parasites in humans, which reside in the eyelids, sebaceous glands, and ear canal, and can cause clinical disease. The purpose of this study was to investigate the possible role of Demodex parasites in causing discomfort in patients referred to Tehran laboratories due to hair loss.
Methods: This cross-sectional study was conducted on 520 patients referred to a laboratory in Tehran, Iran, presenting with hair loss. Sampling was performed from the scalp and face, and samples were examined for Demodex mites using light microscopy.
Results: The results showed that among the 520 patients referred to the laboratory, 66.15% were infected with Demodex. Out of 344 positive cases, 83.43% were women and 16.57% were men. Among the affected patients aged between 7 and 70 years, most patients (59.01%) were in the age group of 25.4 to 39.2 years. A high prevalence of Demodex infestation (66.15%) was found among patients with hair loss.
Conclusion: Our findings establish a highly significant, direct correlation between the severity of hair loss and the density of Demodex mite infestation (p< 0.001). We propose that high Demodex mite density is a significant contributory factor in the etiology of severe hair loss.

Isolation and Diagnosis of Medically Significant Parasites from the American Cockroach (Periplaneta americana) in Shendi City, Sudan

Yassir Sulieman — 2025-12-23

Background: Cockroaches are ubiquitous in residential environments and can act as vectors for pathogens relevant to public health. This investigation aimed to determine the diversity, prevalence, and intensity of parasites carried by the American cockroach, Periplaneta americana, in Shendi City, Sudan.
Methods: A total of 117 P. americana specimens were collected during the summer of 2021 from residential kitchens, bathrooms and sewers using jar traps baited with bread. Following euthanasia by freezing each cockroach was examined for external and internal parasite stages (cysts and ova) via standard parasitological techniques.
Results: The overall parasite prevalence was 31.6%, with a mean intensity of 6.7 parasites per infected insect. Eight species were detected: three protozoans (Entamoeba histolytica/dispar, Entamoeba coli, Giardia lamblia) and five helminths (Ascaris lumbricoides, Trichuris trichiura, Ancylostoma sp., Taenia sp., Enterobius vermicularis). Entamoeba coli was the most prevalent (10.3%), followed by E. histolytica/dispar (7.7%), T. trichiura and Ancylostoma sp. (0.9% each). Taenia Parasite prevalencesp. showed the highest infection intensity (8.6) compared to the lowest (4.0), E. vermicularis and T. trichiura. Statistically, the parasite prevalence and intensity were significantly greater on the cockroaches' body surfaces compared to their digestive tracts (P< 0.001). Adult cockroaches also demonstrated significantly higher infection rates and intensities than nymphs.
Conclusion: The findings confirm that the cockroach, P. americana, can serve as a mechanical vector for protozoan and helminth parasites. Implementing preventive strategies, including improved sanitation and comprehensive pest management, is crucial to reducing the associated public health threat.

Chemical Composition and Control Potential of Melia azedarach Extracts Against Culex pipiens

Wail Ismael Hassan — 2025-12-23

Background: Culex pipiens (Diptera: Culicidae) poses a persistent global health challenge. The overuse of synthetic insecticides has led to resistance and environmental damage, underscoring the need for sustainable alternatives. Melia azedarach (Meliaceae) represents a promising source of bioactive compounds. This study aimed to comprehensively evaluate the potential of alkaloid extracts from M. azedarach against all life stages of Cx. pipiens and to characterize their phytochemical composition.
Methods: Crude alkaloid extracts were prepared from both plant parts. Ovicidal, larvicidal, pupicidal and adult repellent effects, were assessed through laboratory bioassays. The chemical profile of the extracts was determined using Gas Chromatography-Mass Spectrometry (GC-MS).
Results: Bioassays demonstrated significant ovicidal activity, with 100% egg mortality at 1% (w/v) concentration. Larvicidal activity was also notable at 1% (w/v). The fruit extract caused 100% mortality across the first three larval instars, while the leaf extract caused 100% mortality in the first two instars and 96.6% in the third. In the fourth instar, larvae showed 93.33 and 91.67% mortality with the fruit and leaf extracts, respectively. The extracts exhibited significant repellent effects, with rates of 63.00% and 60.00% at 1% (w/v) and consistently negative equilibrium ratios. GC-MS analysis showed the fruit extract was rich in insecticidal fatty acid esters, while the leaf extract contained repellent terpenoids like Piperitenone Oxide. Linoleic acid was a major shared compound, potentially underpinning the broad-stage efficacy.
Conclusion: These findings support the use of M. azedarach extracts as a promising, locally accessible and environmentally responsible strategy for integrated Cx. pipiens mosquito management.