18 months on: an interrupted time series analysis investigating the effect of COVID-19 on chlamydia and gonorrhoea testing and test positivity at the Gold Coast, Australia.

BACKGROUND: STI rates have been reported as reduced during the height of the COVID-19 pandemic. Our study evaluates the number of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections recorded relative to the number of tests performed in 2017-2021, thus accurately depicting trends over time and evaluate the effect of COVID-19 restrictions since these were implemented in March 2020. METHODS: Data was extracted from an electronic database of pathology and clinical records used at Gold Coast Sexual Health Service (GCSHS) in Queensland, Australia from January 2017 to October 2021. Poisson regression-based interrupted time series analyses were performed for number of tests performed and test positivity over the study period. The COVID-19 period was defined as starting from March 2020 when public health directives were implemented. RESULTS: CT and NG testing dropped significantly in the month after COVID-19 restrictions were brought in, by 30% and 23% respectively. Over the 5year study period, the proportion of positive CT tests has consistently decreased by approximately 0.33% points per year (P ≤0.001). The instigation of COVID-19 restrictions had no effect on this trend. The proportion of NG positive tests remained steady prior to COVID-19 (P =0.96) at approximately 3.5%, decreased immediately at the onset of COVID-19 restrictions to approximately 2.5% (P <0.001) and has remained at this level post-COVID restrictions (P =0.54). Testing at GCSHS continued to target gay and bisexual men, accounting for ≥50% of all tests performed. CONCLUSION: Our study suggests that there has been a sustained reduction in test positivity of NG infections in the 18months since COVID-19 restrictions were implemented, and that this is not an artifact of reduced testing. It highlights the importance of maintaining health messaging including screening for sexually transmissible infections and maintaining access to services, which may include alternative models of care such as Telehealth, self-testing and collaboration between all sexual health service providers.

Comparative photobiology of psoralens.

The comparative photobiological effects of several furocoumarins [i.e., angelicin, psoralen, 8-methoxypsoralen (8-MOP), and 5-methoxypsoralen (5-MOP)] have been evaluated in a number of biological systems. The photosensitized induced lethality and genetic damage have been assessed in bacterial, animal, and human cells, and the rank order of effectiveness established psoralen as the most active compound followed by 8-MOP, 5-MOP, and angelicin, 5-MOP and 8-MOP are, however, essentially equally active in the production of chromosome damage in human cells in vitro.

Chromosomal damage induced by furocoumarins and UVA in hamster and human cells including cells from patients with ataxia telangiectasia and xeroderma pigmentosum.

The comparative photosensitizing effects to near-UV irradiation (UVA) of several naturally occurring furocoumarins, 5-methoxypsoralen (5MOP), psoralen, 8-methoxypsoralen (8MOP) and angelicin in producing chromosome damage in vitro in cells derived from hamster, normal human, ataxia telangiectasia (AT) and xeroderma pigmentosum (XP) patients were studied. In Chinese hamster cells, lethality was greatest with psoralen and least with angelicin; 8MOP and 5MOP were intermediate. 8MOP and 5MOP produced sister-chromatid exchanges with almost equal efficiency and to a larger extent by far than angelicin. In all human cell lines studied, 8MOP and 5MOP were similarly effective in the production of sister-chromatid exchanges and chromosomal aberrations. AT and XP cells responded with higher frequencies of sister-chromatid exchanges as well as chromosomal aberrations than normal human cells to 5MOP, 8MOP and angelicin. Evidence is presented which suggests that cell death in Chinese hamster cells following angelicin photosensitization is not clearly related to the production of sister-chromatid exchanges. AT cells were unexpectedly more sensitive to angelicin than normal cells. The presence of 5MOP in some sun-tan preparations is not acceptable in view of the present evidence of its biological activity.

Photobiological studies with dictamnine, a furoquinoline alkaloid.

Dictamnine, a naturally occurring furoquinoline, produces bacterial frameshift mutations in the dark. It does not form DNA interstrand crosslinks in bacterial cells in the presence of near-ultraviolet light (300-380 nm). It is more active than angelicin but slightly less active than 8-MOP as a phototoxic agent with E. coli. It is however a more active mutagen than 8-MOP at equivalent concentration. Dictamnine is slightly more potent than the same concentration of angelicin in producing photosensitized lethality in Chinese hamster cells. It does, however, produce almost twice as many sister-chromatid exchanges per lethal event than angelicin. The concept of 'unit dose' relating the observable photoinduced damage by the photosensitizer and the total irradiation appears to apply reasonably well to the actions of dictamnine in killing bacterial and mammalian cells, in the formation of sister-chromatid exchanges, but not to the induction of bacterial mutations.

Three cases of cowpox infection of domestic cats.

Since October 1982 three cases of cowpox infection of the cat have been presented at a veterinary practice. The disease began as a focal dermatitis on the face or paws which spread after several days to the rest of the body. Two weeks after appearing the pocks scabbed over and fell off leaving hairless skin. There were few systemic signs and therapy did not appear to influence the course of the disease. Diagnosis was confirmed by the demonstration of pox virions or inclusion bodies in skin biopsy or scab material using electron microscopy and by isolation of cowpox virus in chick embryos. High antibody titres to cowpox were observed in the sera of two cats.

Pox virus infection of a domestic cat.

Pox virus infection of a domestic cat is reported. It was manifest clinically as a skin infection which resolved within two months. Histopathology and electron microscopy of the epidermis revealed inclusion bodies typical of pox virus infection. Serological examination of convalescent serum confirmed recent pox virus infection. Cow pox virus was considered as the most likely infectious agent in this case.

Photobiological activity of 5,7-dimethoxycoumarin.

Some biological properties of 5,7-dimethoxycoumarin (DMC) include dark induced frameshift mutagenesis in bacteria, lethal photosensitization and the formation of sister chromatid exchanges in Chinese hamster cells. The number of sister chromatid exchanges per unit of cell lethality produced by DMC is almost the same as observed with 5-methoxypsoralen.

The adequacy of consent forms for informing patients entering oncological clinical trials.

The impact on 100 patients of information and consent forms signed prior to medical oncology clinical trials was evaluated by a survey at a subsequent visit. Only 40 patients believed that the purpose of the form was to explain the treatment. The form was listed as the major source of information by 12 patients while 52 listed a doctor and 26 a nurse. Although 21 patients believed that the form mad them less anxious, 19 patients believed that it made them more anxious. Despite 80 patients reading all of the form, 60 claiming to understand all of it and 68 claiming that in contained adequate information, in tests of recall only 52 patients could name all of their drugs and only 4 all of the side effects. The number of drugs named correlated with how much of the consent form had been read (p = 0.003) and the highest education level achieved by the patient (p = 0.0003). Patients under 55 years had significantly better recall. Patients with a better ECOG performance status were more likely to find the form very helpful. Such forms may not ensure that the requirements for informed consent are satisfied.

5-Methoxypsoralen, an ingredient in several suntan preparations, has lethal, mutagenic and clastogenic properties.

Many furocoumarins found in several species of plant are potent photosensitizing agents known to cause lethal and mutagenic effects in a wide range of organisms, from viruses to man. Their role in the aetiology of cancer is debatable, but work has focused on the PUVA (psoralen-UVA) treatment of psoriasis with 8-methoxypsoralen (8-MOP) and near UV radiation. Bergaptene (5-methoxypsoralen, 5-MOP) is a major constiutent of oil of bergamot, and might be expected to have qualitatively similar photosensitizing properties to 8-MOP. Although 5-MOP is widely used as a stimulus to melanin deposition in several suntan preparations surprisingly little is known about its basic photobiology. We report here that 5-MOP has the expected properties of other biologically active furocoumarins. These properties include lethal and mutagenic photosensitization of bacteria, 'dark' induced frameshift mutagenesis in bacteria, and lethal and clastogenic effects on mammalian cells in tissue culture.

Oxypeucedanin, a Major Furocoumarin in Parsley, Petroselinum crispum.

Fresh parsley leaves and roots were analyzed by HPLC and photobiological assay for photoactive furocoumarins. Oxypeucedanin ( 7), not previously reported from parsley, was found to be the major component (70-100 ppm wet weight). Although only moderately photoactive, its high concentration in parsley may be partially responsible for contact photodermatitis. Other photoactive compounds, namely 5-MOP ( 2), 8-MOP ( 3), psoralen ( 1), isopimpinellin ( 4) and imperatorin ( 5) were also present and quantified.