Muthukumaravel Subramanian

Introduction: This study analyzed the age and sex distribution of COVID-19 patients during the initial three COVID-19 waves in Puducherry, India, from August 2020 to March 2022, to understand the distribution of infection across different demographic groups. Methods: The disease surveillance program conducted at ICMR-Vector Control Research Centre processed 79,705 Throat Swab/Nasal Swab (TSNS) samples received from various institutions in Puducherry through the Integrated Disease Surveillance Program (IDSP). Real-time reverse-transcriptase-polymerase chain reaction (rRT-PCR) was performed following approved protocols. Results: Test positivity rates during the second (14.6%) and third waves (25.1%) were significantly higher than the first wave (11.4%). In the first wave, children (p < 0.001) and elderly individuals (p = 0.017) had a lower risk of testing positive than adults. However, in the second wave, elderly individuals had a 1.12 (95% CI: 1.03 – 1.23) times greater risk of contracting COVID-19 (p = 0.013). Children had a lower risk of testing positive across all waves (p < 0.001). A significant sex difference was noted only in the first wave, with males having a 1.27 (1.18-1.37) times greater chance of being COVID-19 positive. The mean age of female patients was significantly younger than male patients in the third wave (p = 0.008). The third wave showed an increasing trend of infection across all age groups and sexes, especially among younger individuals. Conclusions: The study highlights an increasing trend of infections across all age groups and sexes during the third wave. Micro-epidemiological analyses are crucial for developing targeted intervention strategies that address age and sex demographics effectively.

Cutaneous leishmaniasis (CL) is a significant public health concern that affects many countries. This disease is caused by the protozoan parasite Leishmania spp. and is transmitted through the sandflies from the genus Phlebotomus and Lutzomyia. The clinical manifestations of CL can vary, often leading to challenges in accurate diagnosis and treatment. In 2022, a 51-year-old male patient presented to a tertiary care hospital in Puducherry, India, with progressively worsening facial lesions and granulomatous plaques. The patient had recently returned from Saudi Arabia, where he likely contracted the infection. Before he visited the tertiary care hospital in Puducherry, the patient had been misdiagnosed and treated for conditions such as Erysipelas and Acute Cutaneous Lupus Erythematosus (ACLE), highlighting the diagnostic challenges associated with CL. Skin scrapings from the patient were subjected to real-time PCR, confirming Leishmania spp.’s presence. Cytological examinations revealed the amastigote-like structures within macrophages, thereby establishing the identity of the parasite. For precise species-level identification, PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) and Sanger sequencing of the Internal Transcribed Spacer-1 (ITS-1) region were performed. Molecular techniques confirmed the infection as being caused by Leishmania tropica. Following the accurate diagnosis, the patient was successfully treated with Liposomal Amphotericin B, a treatment known for its efficacy against Leishmania infections. This case underscores the critical importance of considering cutaneous leishmaniasis in the differential diagnosis of travelers returning from endemic areas who present with dermatological manifestations. The initial misdiagnosis and inappropriate treatment highlight the need for heightened clinical awareness and the utilization of advanced diagnostic tools for accurate identification. Effective and timely treatment, as demonstrated in this case, is essential for the management and control of the disease. This report emphasizes the necessity of vigilance among healthcare providers to recognize and appropriately address imported cases of cutaneous leishmaniasis.

In recent years, the emergence of insecticide resistance has been a major challenge to global public health. Understanding the molecular mechanisms of this phenomenon in mosquito vectors is paramount for the formulation of effective vector control strategies. This review explores the current knowledge of insecticide resistance mechanisms through omics approaches. Genomic, transcriptomic, proteomic, and metabolomics approaches have proven crucial to understand these resilient vectors. Genomic studies have identified multiple genes associated with insecticide resistance, while transcriptomics has revealed dynamic gene expression patterns in response to insecticide exposure and other environmental stimuli. Proteomics and metabolomics offer insights into protein expression and metabolic pathways involved in detoxification and resistance. Integrating omics data holds immense potential to expand our knowledge on the molecular basis of insecticide resistance in mosquitoes via information obtained from different omics platforms to understand regulatory mechanisms and differential expression of genes and protein, and to identify the transcription factors and novel molecules involved in the detoxification of insecticides. Eventually, these data will help construct predictive models, identify novel strategies, and develop targeted interventions to control vector-borne diseases.

This study investigates the biodegradation of methyl parathion, an organophosphate pesticide used in paddy fields. Microbial degradation transforms toxic pesticides into less harmful compounds, influenced by the microbial community in the soil. To isolate different microbial colonies, soil samples from an organophosphorus‐treated groundnut field were plated on nutrient agar and MSM with 1% glucose and 0.25 mM methyl parathion. Biodegradation efficiency was determined by estimating the OP hydrolase enzyme activity spectrophotometrically. HPLC was used to quantify residual methyl parathion concentrations in the culture medium. The identified isolate effectively degraded methyl parathion in MSM with 0.25 mM methyl parathion which showed peak hydrolase activity (2.02 µmol/min/mg) after 96 h of incubation and the residual methyl parathion level was determined as 6.2 µmol by HPLC quantification. The efficient isolate was identified as Bacillus cereus by using a 16S rRNA molecular marker and the sequence was subjected to MEGA11 phylogenetic tree construction. The results show that the SM6 clade shared with B. cereus 16S rRNA sequence. B. cereus (SM6) showed substantial enzyme activity and the specific reported opdA gene‐coded protein is involved in ATP hydrolysis. This OP hydrolase makes it a strong candidate for bioremediation of methyl parathion. Molecular analysis suggested that the opdA gene, likely chromosomally located, plays a key role in degradation, with potential involvement of the “Cell division protein FtsK” gene responsible for hydrolase activity. Organophosphorus compounds, widely used in agriculture, pose environmental concerns due to their persistence. This study focuses on isolating pesticide‐degrading bacteria to expedite bioremediation, aiming for efficient degradation. This study highlights the cross‐adaptation phenomenon, where B. cereus strains degrade similar compounds, improving bioremediation strategies.

Hard ticks (Ixodidae) play a critical role in transmitting various tick-borne diseases (TBDs), posing significant global threats to human and animal health. Climatic factors influence the abundance, diversity, and vectorial capacity of tick vectors. It is imperative to have a comprehensive understanding of hard ticks, pathogens, eco-epidemiology, and the impact of climatic changes on the transmission dynamics of TBDs. The distribution and life cycle patterns of hard ticks are influenced by diverse ecological factors that, in turn, can be impacted by changes in climate, leading to the expansion of the tick vector’s range and geographical distribution. Vector competence, a pivotal aspect of vectorial capacity, involves the tick’s ability to acquire, maintain, and transmit pathogens. Hard ticks, by efficiently feeding on diverse hosts and manipulating their immunity through their saliva, emerge as competent vectors for various pathogens, such as viruses, parasites and bacteria. This ability significantly influences the success of pathogen transmission. Further exploration of genetic diversity, population structure, and hybrid tick vectors is crucial, as they play a substantial role in influencing vector competence and complicating the dynamics of TBDs. This comprehensive review deals with important TBDs in India and delves into a profound understanding of hard ticks as vectors, their biology, and the factors influencing their vector competence. Given that TBDs continue to pose a substantial threat to global health, the review emphasizes the urgency of investigating tick control strategies and advancing vaccine development. Special attention is given to the pivotal role of population genetics in comprehending the genetic diversity of tick populations and providing essential insights into their adaptability to environmental changes.

A survey was conducted to determine the human tick-borne bacterial infections in the nymphs which were collected from Western Ghats’ fringe forest areas. Tick nymphs were collected using the flagging method from the villages where cases Kyasanur Forest Disease (KFD) were previously reported in the states of Goa, Karnataka and Maharashtra. A total of 200 tick pools consisting of 4587 nymphs were tested by PCR for the detection of bacteria of public health importance, such as Coxiella burnetii and Rickettsia spp. Of these, four pools (4.8%) in Karnataka and three pools (4.4%) in Maharashtra were positive for Coxiella burnetii, while none of the samples from Goa state were positive. Rickettsia spp. were positively obtained from Maharashtra (51.5%), Goa (35.42%) and Karnataka (26.19%). The sequence results of Rickettsia spp. showed similarity to the spotted fever group Candidatus Rickettsia shennongii, Rickettsia conorii subsp. heilongjiangensis and Rickettsia spp. strain koreansis. Individuals are entering into the forest areas for various reasons are more likely to infect with Coxiella burnetii. and Rickettsia spp.