An algorithm to estimate the real time secondary infections in sub-urban bus travel: COVID-19 epidemic experience at Chennai Metropolitan city India.

Globalization, global climatic changes, and human behavior pose threats to highly pathogenic avian influenza (HPAI) virus spillover from animals to human. Current SARS-CoV2 transmission continues in several countries despite drastic reduction in COVID-19 cases following world-wide containment measures including RNA vaccines. China reimposed lockdown in November 2022 following the surge in commercial hubs. Urban population density and intracity travel in over-crowded public transport play crucial roles in early transition to an exponential phase of the epidemic in metro-cities. Based on the SARS-CoV2 transmission during the lockdown period in Chennai metro-city, we developed an algorithm that mimics a real-time scenario of passengers boarding and deboarding at each bus-stop on a trip of 36.1 km in 21G bus service in Chennai city to understand the pattern of secondary infections on a daily basis. The algorithm was simulated to estimate R0, and the COVID-19 secondary infections was estimated for each bus trip. Results showed that the R0 depended on the boarding and deboarding of the infected individuals at various bus stops. R0 varied from 0 to 1.04, each trip generated 5-9 secondary infections and four bus stops as potential locations for a higher transmission level. More than 80% of the working population in metro-cities depends on unorganized sectors, and separate mitigation strategies must be in place for successful epidemic containment. The developed algorithm has significant public health relevance and can be utilized to draw necessary containment plans in near future in the event of new COVID-19 wave or any other similar epidemic. Supplementary Information: The online version contains supplementary material available at 10.1007/s13337-022-00804-9.

Extensive myiasis of the leg in a patient with filarial lymphedema: implications for morbidity care in filariasis elimination program.

Myiasis, infestation of the human body by larva of flies is an under-recognized and ignored medical condition. Not only is this condition unsightly and extremely distressing to the patient, but it also generates a ghastly feeling in care givers and health care workers as well. The authors report extensive myiasis of the leg in a patient with filarial lymphedema from southern India, which is rarely illustrated in published literature. Treatment of myiasis is described in brief. There is a need for strengthening morbidity management in filariasis elimination program.

Clinical Benefits of Supervised Home Care of the Morbidity Management and Disability Prevention Under National Filariasis Elimination Programme.

Introduction: Mass drug administration and morbidity management and disability prevention (MMDP) though considered as two pillars of global program for elimination of filariasis, implementation of MMDP was disregarded in several endemic countries. Limb hygiene is the main component of MMDP and to address its overall clinical benefits, a community-based study was undertaken in three sets of populations. Materials and Methods: After obtaining written informed consent, clinical, quality of life (QoL) assessments were carried out and lymphedema volume was measured for three groups of lymphedema patients at intake, at 6, and 12 months follow-up. Filarial lymphedema patients from three sets of villages categorized as "Previous VCRC MMDP," "State MMDP," and "Current VCRC MMDP" were considered for the study. Clinical examination and QoL assessment were carried out independently by a medical officer and a sociologist, respectively. Whoever available at the time of three field visits were registered and included in the study. In total, 67, 63, 66 and 75, 74 and 63 lymphedema (LE) patients completed clinical evaluation and QoL assessment from these groups, respectively. Results: Assessment of repeated measures of clinical parameters at baseline and two time points of follow-up by Friedman's test showed significant clinical improvements in skin color, texture, moisture, and ulcer (p > 0.05), in nails score and intertrigo score (p > 0.01). Assessed by Wilcoxon signed-rank test showed a significant reduction in the frequency Acute Dermato-Lymphangio-Adenitis episodes at 12 months follow-up in all the three MMDP groups (p < 0.001). However, the reduction of LE volume was significant (p = 0.009) only in the current Vector Control Research Centre (VCRC) MMDP group. There was no significant improvement in the QoL in all three groups. Conclusions: To achieve the desired clinical benefits by MMDP home care practices for the filarial lymphedema patients, regular monitoring by the auxiliary health workers is essential. National programs must consider monthly supervision through an integrated approach.

Risk Factors for Chronic Intertrigo of the Lymphedema Leg in Southern India: A Case-Control Study.

Rich clinical experiences indicate that toe web intertrigo is a major predisposing condition for cellulitis/acute dermatolymphango adenitis (ADLA) and the number of lesions is the strongest predictor of frequency of ADLA in lymphedema (LE) patients. However, there is scanty information on the risk factors for the establishment of chronic toe web intertrigo in LE patients. We performed a case-control study recruiting 52 lower limb LE with intertrigo and 52 lower limb LE without intertrigo in community settings and assessed general and local potential risk factors for chronic intertrigo. Analysis of local risk factors revealed that topical application of oil, tingling and numbness of the extremities were associated independently with chronic intertrigo. In multivariate analysis, LE grades III and IV were associated with chronic intertrigo, after adjusting for tingling and numbness, prophylactic antibiotic, age group, and gender. From a public health perspective, LE patients of grades III and IV and patients under antibiotic prophylaxis should be self-motivated to look for the early symptoms of toe web intertrigo to prevent chronic stage and recurrent episodes of cellulitis. Patients with history of tingling and numbness of the periphery need to be monitored for pressure effects leading to poor vascularization and delayed healing of intertrigo.

Synthesis of silver nanoparticles from Azadirachta indica--a most effective method for mosquito control.

Mosquitoes transmit major communicable diseases such as dengue, malaria, filariasis, Japanese encephalitis, chikungunya, and so on. Vector control is important in epidemic disease situations as there is an urgent need to develop new and improved mosquito control methods that are economical and effective yet safe for non-targeted organisms. In the present study, silver nanoparticles (AgNPs) were synthesized from the aqueous leaf extract of neem plant (Azadirachta indica), and their effects on mosquito vectors (Aedes aegypti and Culex quinquefasciatus) were assessed. The synthesised AgNPs were characterized by UV-vis spectroscopy, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction analysis (XRD). The nanoparticles have maximum absorption at 442 ± 1.5 nm with an average size of 41-60 nm. The XRD data showed six well-defined diffraction peaks, corresponding to a relative intensity of the crystal structure of metallic silver 36.42, 100.00, 53.70, 14.20, 16.05, and 6.79, respectively. The FT-IR data showed strong prominent peaks in different ranges, reflecting its complex nature. The mosquito larvae were exposed to varying concentrations of AgNPs synthesized from the neem leaves under investigation (0.07-25 mg/l) for 24 h; this revealed larvicidal activity of AgNPs with LC50 and LC90 values of 0.006 and 0.04 mg/l for A. aegypti, respectively. Further, the LC50 and LC90 values were also identified as 0.047 and 0.23 mg/l for Cx. quinquefasciatus, respectively. The result obtained from this study presents biosynthesized silver nanoparticle from A. indica as the biolarvicidal agent with the most potential for mosquito control.