Recent reports have suggested that cotton leaf curl virus (CLCuV), a geminivirus of the genus Begomovirus, may be responsible for cotton leaf curl disease in Pakistan. However, the causal agent of the disease remains unclear as CLCuV genomic components resembling begomovirus DNA A are unable to induce typical disease symptoms when reintroduced into plants. All attempts to isolate a genomic component equivalent to begomovirus DNA B have been unsuccessful. Here, we describe the isolation and characterisation of a novel circular single-stranded (ss) DNA associated with naturally infected cotton plants. In addition to a component resembling DNA A, purified geminate particles contain a smaller unrelated ssDNA that we refer to as DNA 1. DNA 1 was cloned from double-stranded replicative form of the viral DNA isolated from infected cotton plants. Blot hybridisation using probes specific for either CLCuV DNA or DNA 1 was used to demonstrate that both DNAs co-infect naturally infected cotton plants from different geographical locations. DNA 1 was detected in viruliferous Bemisia tabaci and in tobacco plants infected under laboratory conditions using B. tabaci, indicating that it is transmitted by whiteflies. Sequence analysis showed that DNA 1 is approximately half the size of CLCuV DNA but shares no homology, indicating that it is not a defective geminivirus component. DNA 1 has some homology to a genomic component of members of Nanoviridae, a family of DNA viruses that are normally transmitted by aphids or planthoppers. DNA 1 encodes a homologue of the nanovirus replication-associated protein (Rep) and has the capacity to autonomously replicate in tobacco. The data suggest that a nanovirus-like DNA has become whitefly-transmissible as a result of its association with a geminivirus and that cotton leaf curl disease may result from a mutually dependent relationship that has developed between members of two distinct DNA virus families that share a similar replication strategy.

The highly contagious and deadlycoronavirus disease 2019 (COVID-19) has caused significant disruption in the small care sector of Pakistan. This study accordingly explores the perceptions and experiences of staff providing direct caregiving services to the elderly residents at three care homes during the time of the coronavirus pandemic in Karachi, Pakistan. Design: Using a qualitative approach, 27 digitally recorded, semi-structured, face-toface interviews were performed with current and former caregiving staff members. The data were analyzed through qualitative content analysis. Results: Analysis highlights various kinds of challenges that were faced by the caregivers and their families during the pandemic. The main theme class identified from the data was "living in anxiety and fear." The work-related decisions made by caregivers at that time were mainly influenced by their familial demands and responsibilities. Conclusion: Caregivers were at risk of catching the lethal virus through inhalation of or physical contact with infectious particles, but despite that most of them continued to render elderly care services. This study's findings could be used by government leaders and care home administrations when making coronavirus containment policies, designing economic relief packages, and formulating caregiving training programs in Pakistan or other countries in the world.

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