Changing patterns of household transmission of tuberculosis in an eastern state of India: The impact of COVID19 pandemic.

BACKGROUND: The COVID-19 Pandemic has affected many components of the Tuberculosis (TB) control program. Due to lockdown and restrictions, people, including TB patients, might have spent more time in the household. There might be an increased TB transmission among the household contacts (HHC). The current study was conducted to measure the household transmission of TB and also find out the relationship with several clinico-social factors. METHODS: Contact tracing data of West Bengal, India, was extracted from Nikshay portal of Central TB Division, Government of India. The anonymized data was divided into two parts, firstly before the lockdown initiation in India and secondly during the lockdown. A modified Poisson regression model was developed to determine the statistical association between clinico-social variables and the pandemic with household-level secondary TB cases. RESULTS: There was a 30% reduction in daily TB case notification, but the proportion of HHC screened was 4% higher during the pandemic than the pre-pandemic period. The secondary attack rate of household TB disease transmission was 34% lower during the pandemic period. Index TB patients aged under ten years, microbiologically positive, Drug-Resistant TB, having three or more HHCs, treatment delay more than seven days, notified from the private sector, and diagnosis during the pre-pandemic period was found to be independently associated with a higher risk of having a secondary TB case at household. CONCLUSION: The risk of household TB transmission was significantly lower during the pandemic period compared to the pre-pandemic period, which may be due to better infection prevention and control practices.

Treatment adherence status of the TB patients notified from private sector and its associated factors: Findings of a secondary data analysis from West Bengal, India.

INTRODUCTION: In India, each year, estimated one million TB cases are missing from notification, most of them being diagnosed treated in private sector. The large number of patients in private sector has raised concerns about suboptimal quality of care; lack of systems for treatment adherence thus raising the risk of drug resistance. The current analysis was conducted to find out the status of TB treatment adherence in private sector & to identify the factors associated with poor TB treatment adherence. METHODS: Analysis of secondary data obtained through adherence monitoring house visit by THALI (an USAID funded project) field workers during July 2018-June 2019, was done. RESULTS: Default rate among the private patients was 5%. Among the private TB patients 81.6% & among the defaulter 87.3% were in the age bracket of 15-59 years. Reasons stated for being a defaulter were 'Medicine is not working' (30%), 'Travel' (28.6%), 'Cost involved in the treatment' (21.8%), 'Side effects of ATD' (11.6%), 'Anxiety or Depression' (7.2%) & 'Feeling of completely cured' (0.8%). Despite best of efforts only 36.9% defaulter could be retrieved. Factors associated with increased risk of lost to follow-up were 15-59 years age, male sex, earning member of the family,tobacco user, alcohol user, DR-TB, continuation phase of treatment, previous history of TB, presence of symptoms & inability to walk. CONCLUSION: Privately treated TB patients are vulnerable for non-adherence. Once defaulted, it is difficult to retrieve them. Economically productive age group is at higher risk of being defaulter. Commonest reason for lost to follow up is wrong impression about TB medicine. Program should think of extensive engagement & sensitization drive for the private providers; Strict adherence monitoring of private TB patients, extensive advocacy communication & social mobilization program in the community & workplaces/institutions.

Theoretical investigation of the gas-phase reactions of CF2ClC(O)OCH3 with the hydroxyl radical and the chlorine atom at 298 K.

A Theoretical study on the mechanism of the reactions of CF2ClC(O)OCH3 with the OH radical and Cl atom is presented. Geometry optimization and frequency calculations have been performed at the MPWB1K/6-31+G(d,p) level of theory and energetic information is further refined by calculating the energy of the species using G2(MP2) theory. Transition states are searched on the potential energy surface involved during the reaction channels and each of the transition states are characterized by presence of only one imaginary frequency. The existence of transition states on the corresponding potential energy surface is ascertained by performing intrinsic reaction coordinate (IRC) calculation. Theoretically calculated rate constants at 298 K and atmospheric pressure using the canonical transition state theory (CTST) are found to be in good agreement with the experimentally measured ones. Using group-balanced isodesmic reactions as working chemical reactions, the standard enthalpies of formation for CF2ClC(O)OCH3, CF2ClC(O)OCH2 and CF3C(O)OCH3 are also reported for the first time.

Theoretical study on rate constants for the reactions of CF3CH 2NH 2 (TFEA) with the hydroxyl radical at 298 K and atmospheric pressure.

Theoretical investigations are carried out on reaction mechanism of the reactions of CF3CH2NH2 (TFEA) with the OH radical by means of ab initio and DFT methods. The electronic structure information on the potential energy surface for each reaction is obtained at MPWB1K/6-31+G(d,p) level and energetic information is further refined by calculating the energy of the species with a Gaussian-2 method, G2(MP2). The existence of transition states on the corresponding potential energy surface is ascertained by performing intrinsic reaction coordinate (IRC) calculation. Our calculation indicates that the H abstraction from -NH2 group is the dominant reaction channel because of lower energy barrier. The rate constants of the reaction calculated using canonical transition state theory (CTST) utilizing the ab initio data. The agreement between the theoretical and experimental rate constants is good at the measured temperature. From the comparison with CH3CH2NH2, it is shown that the fluorine substution decreases the reactivity of the C-H bond.