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Weekly Digest: Vaccination reduces household transmission of COVID-19; Verbal autopsy data shows leading causes of death among children in camps for internally displaced people in Somalia; RSV cases rising among children in Japan

Vaccination reduces household transmission of COVID-19 in England. Researchers in England recently investigated whether vaccination against COVID-19 reduces transmission in households in the context of postvaccination infection. In early 2021, there were 960,765 household contacts of unvaccinated index patients and 96,898 reported secondary cases (10.1%). The likelihood of household transmission was 40-50% lower in households of patients vaccinated more than three weeks before testing positive. [NEJM]

Risk-based COVID-19 vaccine allocation reduces hospitalization, deaths and maximizes equitable distribution. A US simulation study assessed the most efficient COVID-19 vaccine allocation strategy to minimize hospitalization and ensure equitable vaccine distribution. The scenarios simulated were random allocation, CDC proxy, age-based, and risk-based. The risk-based approach, which led to the largest reduction in hospitalizations, avoidable COVID-19 deaths, and household transmissions, also led to the highest level of vaccination among Hispanic and Black patients during an eight-month period. [JAMA Network]

B.1.526 rapidly spread in the US and is resistant to many COVID-19 treatments. Researchers recently reported on the emergence of the COVID-19 lineage B.1.526 that came to dominate most COVID-19 cases in New York City in early 2021. Their analysis of 1,507 COVID-19 samples showed that two-thirds of all sequenced isolates were of the B.1.526 and B.1.1.7 lineages. Researchers suggest that partial or complete resistance to antibodies has contributed to its transmission dynamics as neutralizing effects of convalescent plasma and vaccinee sera were lowered by 4.1-fold and 3.6-fold, respectively. [Nature]

COVID-19 vaccines are less effective against the Delta variant in nursing homes. A US Centers for Disease Control and Prevention study evaluated the effectiveness of the Pfizer-BioNTech and Moderna vaccines in preventing COVID-19 infections in nursing home residents before and after the spread of the Delta variant. Vaccine effectiveness in the pre-Delta period neared 74.7% ( 74.2% for Pfizer-BioNTech, and 74.7% for Moderna). However, adjusted effectiveness fell to 53.1% during the Delta period (52.4% for Pfizer-BioNTech, and 50.6% for Moderna). [CDC]

RSV cases rising among children in Japan. Despite intensified infection control measures to control the COVID-19 pandemic, an unusually high number of respiratory syncytial virus (RSV) infections was reported in Tokyo by July 2021; the cumulative number of cases on week 28 of 2021 was 10,327 compared to only 570 in 2020. The emergence of RSV epidemics with unusual patterns and at different seasons has also been observed in the Americas and Australia, warranting mobilization of appropriate control measures and continuous monitoring of the infection. [CDC]

Verbal autopsy data shows leading causes of death among children in camps for internally displaced people in Somalia. A study in southern Somalia used verbal autopsy, among other methods, to collect data on causes of death among children under five in camps for internally displaced people in Southern Somalia between 2016 and 2018. In a cohort of 3898 children, there were 153 deaths during 34,746 person-months of observation. The leading causes of death were diarrhoeal diseases (25.9%), measles (17.8%), and severe malnutrition (8.8%), suggesting that health and nutrition surveillance systems through verbal autopsy can guide public health interventions in humanitarian contexts. [The Lancet]

Study identifies predictors of death in people with MDR-TB. A study in Ethiopia assessed the treatment success rate for multidrug-resistant tuberculosis (MDR-TB) during ten years. In a cohort of 3395 adults with MDR-TB, treatment was successful for 75.7%. The death rate was 12.8%, and treatment failure was 1.7%. While the strongest predictors of death were old age (adjusted hazard ratio (AHR): 1.03), HIV infection (AHR: 2.0), and anemia (AHR:1.7), none were significantly associated with treatment failure. [BMJ]

Pharmaceuticals contaminating watershed in Baltimore. A study in Baltimore used liquid chromatography-mass spectrometry to detect and quantify pharmaceuticals exported from watersheds. Among the 37 compounds detected, acetaminophen was in higher concentrations, especially in streams with higher population densities. Annual pharmaceutical loads at the watershed outlet ranged from less than 1 kg to around 15 kg, equivalent to tens of thousands of human doses. [Environmental Science & Technology ]

New assay distinguishes between M. Tuberculosis and non-tuberculous mycobacterial infections. Researchers from universities in Mali, South Africa, and the USA have developed a new multiplex assay that can differentiate between M. Tuberculosis (MTB) complex and non-tuberculous mycobacteria (NTM), including M. Avium complex (MAC), the most common and treatable NTM. This assay addresses the problem of NTM being clinically indistinguishable from tuberculosis (TB) and may help clinicians in low-resource settings avoid presumptive treatments and combat TB drug resistance. [The Lancet]

Study explores antibiotic-related practices in Uganda. A qualitative study in Uganda used focus groups discussions and key informant interviews to explore access, use, and disposal of antimicrobials among humans and animals. The findings indicate that community members mainly accessed antimicrobials for human use via public health facilities, drug shops, and clinics, while those for animal use were obtained via veterinary practitioners and drug shops. Many incorrect antimicrobial handling practices were reported, including sharing antibiotics among household members, using antibiotics intended for human use as growth promoters for food-producing animals, and improper disposal of antimicrobials as household waste. [BMC]

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