A tale of two waves: Delineating diverse genomic and transmission landscapes driving the COVID-19 pandemic in Pune, India

BACKGROUND

Modern response to pandemics, critical for effective public health measures, is shaped by the availability and integration of diverse epidemiological outbreak data. Tracking variants of concern (VOC) is integral to understanding the evolution of SARS-CoV-2 in space and time, both at the local level and global context. This potentially generates actionable information when integrated with epidemiological outbreak data.

METHODS

A city-wide network of researchers, clinicians, and pathology diagnostic laboratories was formed for genome surveillance of COVID-19 in Pune, India. The genomic landscapes of 10,496 sequenced samples of SARS-CoV-2 driving peaks of infection in Pune between December-2020 to March-2022, were determined. As a modern response to the pandemic, a "band of five" outbreak data analytics approach was used. This integrated the genomic data (Band 1) of the virus through molecular phylogenetics with key outbreak data including sample collection dates and case numbers (Band 2), demographics like age and gender (Band 3-4), and geospatial mapping (Band 5).

RESULTS

The transmission dynamics of VOCs in 10,496 sequenced samples identified B.1.617.2 (Delta) and BA(x) (Omicron formerly known as B.1.1.529) variants as drivers of the second and third peaks of infection in Pune. Spike Protein mutational profiling during pre and post-Omicron VOCs indicated differential rank ordering of high-frequency mutations in specific domains that increased the charge and binding properties of the protein. Time-resolved phylogenetic analysis of Omicron sub-lineages identified a highly divergent BA.1 from Pune in addition to recombinant X lineages, XZ, XQ, and XM.

CONCLUSIONS

The band of five outbreak data analytics approach, which integrates five different types of data, highlights the importance of a strong surveillance system with high-quality meta-data for understanding the spatiotemporal evolution of the SARS-CoV-2 genome in Pune. These findings have important implications for pandemic preparedness and could be critical tools for understanding and responding to future outbreaks.

Intraoperative epicardial echocardiography in assessing pulmonary artery banding procedures

BACKGROUND

Accurate perioperative assessment of the adequacy of pulmonary artery banding has hitherto relied on oximetry and direct pressure measurements. We report the use of epicardial Doppler echocardiography for assessing banding procedures.

METHODS

Six consecutive infants (3 male, 3 female; median age, 17 days) who underwent pulmonary artery banding for complex defects were studied by intraoperative epicardial Doppler echocardiography.

RESULTS

Excellent visualization of the relation of the band to the pulmonary valve and branch arteries was obtained, enabling or confirming optimal positioning. Doppler echocardiographic estimation of the pressure drop across the band was possible in each patient and resulted in further tightening of the band in 2 patients (33%) with satisfactory increases in transband pressure gradients. Intraoperative echocardiographic estimates of the transband gradients (median, 57 mm Hg; range, 52 to 71 mm Hg; mean +/- standard deviation, 59 +/- 7 mm Hg) correlated well with those obtained at subsequent transthoracic echocardiography (median gradient, 66 mm Hg; range, 52 to 67 mm Hg; mean +/- standard deviation, 63 +/- 6 mm Hg).

CONCLUSIONS

Epicardial echocardiography is a valuable adjunct to direct pressure and saturation measurements for adjustment of final band size and aids in confirming accurate band placement.

Univentricular heart with systemic outflow obstruction: palliation by primary Damus procedure

In 24 consecutive infants (19 male and 5 female) with complex forms of single-ventricle physiology and systemic outflow obstruction, a modified Damus operation without the use of exogenous material was undertaken in conjunction with creation of an aortopulmonary shunt 3.5 mm in diameter. The median age at operation was 6 days (range, 1 to 170 days) and the median weight, 3.4 kg (range, 2.6 to 4.6 kg). There were nine early deaths. All 15 survivors (median follow-up, 6.5 months) were clinically well without major systemic ventricular dysfunction or atrioventricular or arterial valve regurgitation. Ten of them have undergone a superior vena cava-pulmonary shunt (one death), and 1 has required patch angioplasty of the aortic arch and innominate artery with revision of the aortopulmonary shunt. The 4 other survivors are awaiting a cavopulmonary shunt. Univariate analysis yielded the chronologic rank for an individual procedure (higher risk of death early in the series), presence of aortic arch atresia, and presence or absence of transposition of the great arteries as predictors of death. This aggressive surgical approach provides excellent early palliation, and because the operation prevents abnormal ventricular hypertrophy from pressure or volume overload, systemic ventricular function is optimally conserved for a future Fontan-type procedure.

Surgery for infants with a hypoplastic systemic ventricle and severe outflow obstruction: early results with a modified Norwood procedure

OBJECTIVE

Prospective audit of the first year of implementation of a modified approach to palliation for infants with hypoplastic systemic ventricle and severe systemic outflow obstruction.

SETTING

Tertiary referral centre for neonatal and infant cardiac surgery.

PATIENTS AND METHODS

17 of 19 infants (aged < 35 days) presenting to Birmingham Children's Hospital in 1993 with hypoplastic systemic ventricle and severe outflow obstruction underwent surgery. This was performed using a new modification of the Norwood-type arch repair, without the use of exogenous material, and a 3.5 mm Gore-tex shunt between the innominate and right pulmonary arteries. The Gore-tex shunt was replaced by a cavopulmonary shunt between 3 and 5 months later. Clinical, morphological, and functional determinants of outcome were examined.

RESULTS

10 (59%) infants survived initial surgery. All proceeded to cavopulmonary shunt without further loss. Significant atrioventricular valve regurgitation seemed to be the main risk factor for poor outcome. If this was excluded, the morphology of the dominant ventricle seemed to have little effect on the outcome of initial surgery.

CONCLUSIONS

Early survival was achieved in 59% of patients in the first year of implementation of a protocol for surgery in infants with hypoplastic systemic ventricle and severe outflow obstruction. The construction of a neoaorta without the use of exogenous material may allow improved later growth of the neoaorta. Early cavopulmonary shunt can be performed safely and should reduce mid-term complications from cyanosis and systemic ventricular volume loading.