SARS-CoV-2 raw wastewater surveillance from student residences on an urban university campus

The COVID-19 pandemic brought about an urgent need to monitor the community prevalence of infection and detect the presence of SARS-CoV-2. Testing individual people is the most reliable method to measure the spread of the virus in any given community, but it is also the most expensive and time-consuming. Wastewater-based epidemiology (WBE) has been used since the 1960s when scientists implemented monitoring to measure the effectiveness of the Polio vaccine. Since then, WBE has been used to monitor populations for various pathogens, drugs, and pollutants. In August 2020, the University of Tennessee-Knoxville implemented a SARS-CoV-2 surveillance program that began with raw wastewater surveillance of the student residence buildings on campus, the results of which were shared with another lab group on campus that oversaw the pooled saliva testing of students. Sample collection began at 8 am, and the final RT-qPCR results were obtained by midnight. The previous day's results were presented to the campus administrators and the Student Health Center at 8 am the following morning. The buildings surveyed included all campus dormitories, fraternities, and sororities, 46 buildings in all representing an on-campus community of over 8,000 students. The WBE surveillance relied upon early morning "grab" samples and 24-h composite sampling. Because we only had three Hach AS950 Portable Peristaltic Sampler units, we reserved 24-h composite sampling for the dormitories with the highest population of students. Samples were pasteurized, and heavy sediment was centrifuged and filtered out, followed by a virus concentration step before RNA extraction. Each sample was tested by RT-qPCR for the presence of SARS-CoV-2, using the CDC primers for N Capsid targets N1 and N3. The subsequent pooled saliva tests from sections of each building allowed lower costs and minimized the total number of individual verification tests that needed to be analyzed by the Student Health Center. Our WBE results matched the trend of the on-campus cases reported by the student health center. The highest concentration of genomic copies detected in one sample was 5.06 × 10⁷ copies/L. Raw wastewater-based epidemiology is an efficient, economical, fast, and non-invasive method to monitor a large community for a single pathogen or multiple pathogen targets.

Decay of enveloped SARS-CoV-2 and non-enveloped PMMoV RNA in raw sewage from university dormitories

Introduction

Although severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) RNA has been frequently detected in sewage from many university dormitories to inform public health decisions during the COVID-19 pandemic, a clear understanding of SARS-CoV-2 RNA persistence in site-specific raw sewage is still lacking. To investigate the SARS-CoV-2 RNA persistence, a field trial was conducted in the University of Tennessee dormitories raw sewage, similar to municipal wastewater.

Methods

The decay of enveloped SARS-CoV-2 RNA and non-enveloped Pepper mild mottle virus (PMMoV) RNA was investigated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in raw sewage at 4°C and 20°C.

Results

Temperature, followed by the concentration level of SARS-CoV-2 RNA, was the most significant factors that influenced the first-order decay rate constants (k) of SARS-CoV-2 RNA. The mean k values of SARS-CoV-2 RNA were 0.094 day^-1 at 4°C and 0.261 day^-1 at 20°C. At high-, medium-, and low-concentration levels of SARS-CoV-2 RNA, the mean k values were 0.367, 0.169, and 0.091 day^-1, respectively. Furthermore, there was a statistical difference between the decay of enveloped SARS-CoV-2 and non-enveloped PMMoV RNA at different temperature conditions.

Discussion

The first decay rates for both temperatures were statistically comparable for SARS-CoV-2 RNA, which showed sensitivity to elevated temperatures but not for PMMoV RNA. This study provides evidence for the persistence of viral RNA in site-specific raw sewage at different temperature conditions and concentration levels.

Long-term effectiveness of a peer-based intervention to promote condom and contraceptive use among HIV-positive and at-risk women

OBJECTIVE

The authors used data from a larger study to evaluate the long-term effects of a peer advocate intervention on condom and contraceptive use among HIV-infected women and women at high risk for HIV infection.

METHODS

HIV-infected women in one study and women at high risk for HIV infection in a second study were selected from the Women and Infants Demonstration Project and assigned to a standard or an enhanced HIV prevention treatment group. The enhanced intervention included support groups and one-on-one contacts with peer advocates tailored to clients' needs. The authors interviewed women at baseline and at 6-, 12- and 18-months, and measured changes in consistency of condom and contraceptive use and in self-efficacy and perceived advantages and disadvantages of condom and contraceptive use.

RESULTS

Of HIV-infected women, the enhanced group had improved consistency in condom use, increased perceived advantages of condom use, and increased level of self-efficacy compared with the standard group. Of women at risk, the enhanced intervention group at six months maintained consistent condom use with a main partner and perceived more benefit of condom use compared with the standard group. These differences diminished at 12 months.

CONCLUSIONS

The enhanced intervention was generally effective in the HIV+ study. In the at-risk study, however, intervention effects were minimal and short-lived. Factors related to the theory, intervention design, and sample characteristics help explain these differences.

Distribution along a stages-of-behavioral-change continuum for condom and contraceptive use among women accessed in different settings. Prevention of HIV in Women and Infants Demonstration Projects

The numbers of women of childbearing age in the US with HIV and AIDS from heterosexual transmission continues to rise. Behavioral interventions remain the best means of preventing transmission of HIV. Program planners often implement interventions to promote behavioral change in a wide range of settings such as family planning or sexually transmitted disease clinics, drug treatment facilities, or medical facilities that serve high risk and HIV positive women. Women recruited in different types of settings, however, may differ with respect to their experience with, attitudes toward, and willingness to use condoms and contraception. Such differences should be considered when tailoring interventions to the populations being served. We examined the readiness to use condoms and contraception among 3784 women in four cities recruited in three different types of settings: community, facilities not targeted to HIV positive women and medical facilities for HIV positive populations. Readiness to use condoms or contraception was measured using The Transtheoretical Model of Change. Women reported being in different stages along the continuum of condom and contraceptive use in the three settings. A greater proportion of women in the HIV-facility, 45%, had used condoms consistently for the previous 6 months compared to women in the other two settings (12% and 11%). Similarly, variation across settings was seen for contemplation of consistent contraceptive use to prevent unintended pregnancies. The variability in the distribution of condom and contraceptive use across settings underscores the importance of assessing the readiness for the behavior change and designing interventions that meet the specific needs of the populations being served.

Residential radon exposure and lung cancer--an epidemiological study of Norwegian municipalities

The study is based on a collaboration between the Cancer Registry of Norway, the Norwegian Radiation Protection Authority, and National Radiological Protection Board (NRPB, UK). The association between indoor radon exposure and lung cancer was studied in 427 municipalities. NRPB detectors were sent to 10,000 households, and 7,500 of the detectors were returned. Data from a nation-wide survey of smoking habits in 1964-1965 were available. Data on asbestos exposure were also used in a regression analysis. The reporting to the Cancer Registry of all new cases of cancer is fairly complete, as hospital departments and institutes of pathology are obliged to report all cancer cases. The histologically confirmed lung cancer cases were grouped into squamous-cell carcinoma, small-cell carcinoma, adenocarcinoma and other or non-specified histological types. The age-adjusted rate of lung cancer by histological type was the dependent variable in the regression analysis. A consistent increase in incidence of lung cancer was seen with increasing tobacco consumption, but no positive trend could be shown with increasing radon exposure in the descriptive presentation of the data. In the regression analysis, however, the incidence of small-cell anaplastic lung tumors in females increased significantly with increasing radon exposure. When based on the regression coefficients, the fraction of lung cancers attributable to radon is about 2-4%. However, systematic errors cannot be excluded in an ecological study such as presented here.

Factors affecting indoor radon concentrations in the United Kingdom

Data collected in a nationwide study on natural radiation exposure in UK dwellings (Wrixon et al. 1988) were re-analyzed to investigate the effects of rock type and various building and lifestyle characteristics, taken into account simultaneously, on indoor radon concentrations. A multiplicative model which takes into consideration the outdoor radon concentration is used. Indoor radon concentrations were found to be influenced by type of rock underlying the dwelling, double glazing, house type, floor level of rooms in which measurements were taken, window opening habits in the main bedroom, building materials used in the construction of the walls, floor type, and draught proofing. However, these eight factors together account for only 22% of the variation between dwellings. Estimates of the size of the effect associated with each factor are given.

In vivo reassortment of Thogoto virus (a tick-borne influenza-like virus) following oral infection of Rhipicephalus appendiculatus ticks

Arboviruses with segmented genomes have the potential to reassort in both their vertebrate hosts and arthropod vectors. Reassortment of Thogoto virus, a tick-borne orthomyxo-like virus, has been demonstrated following dual infection of hamsters by temperature-sensitive mutants. To investigate whether similar events can occur in ticks, Rhipicephalus appendiculatus larvae and nymphs were dually infected by interrupted feeding on viraemic hamsters. Wild-type reassortant virus was isolated from the ticks 12 to 15 days after engorgement. Following moulting, nymphs and adults transmitted reassortant virus to uninfected hamsters. This is the first reported evidence that a tick-borne arbovirus can reassort in vivo in a naturally infected arthropod vector. The relative roles of vector and vertebrate host in generating and perpetuating reassortant viruses in nature are discussed.

Reassortment of Thogoto virus (a tick-borne influenza-like virus) in a vertebrate host

Reassortment is an important factor in the evolution of segmented genome viruses. For arthropod-borne viruses it is important to determine whether the vertebrate host acts as a site of reassortant virus formation since vertebrates often act as amplifying hosts. Mutants of Thogoto virus, a tick-borne orthomyxo-like virus, were shown to produce wild-type progeny in a dually infected permissive host (hamster), when hamsters were infected with two mutant viruses either by direct inoculation or by oral transmission from infected ticks. Viral dose and time of co-infection of the host affected the incidence of reassortment. This is the first report of reassortment of an arbovirus following infection of a vertebrate host via an arthropod vector.

Redundant spore coat structures in an entomopathogenic Bacillus

An ultrastructural study of an insecticidal bacillus isolated from the silver-spotted skipper (Epargyreus clarus) revealed unusual spore coat redundancy. Spores developed simultaneously with appendages which were always attached to the spore coat and remained attached even after the mother cell had lysed. The appendages were multilobular or attached plates and were encased by lamellar coverings and a fibrous outer coat which were similar to those surrounding the attached spore.

Radon daughter exposures in the U.K

Exposure due to the inhalation of the short-lived daughters of 222Rn is the single largest contributor to the exposure of the U.K. population. A survey of dwellings situated largely in the centers of population indicates an annual exposure of 0.16 WLM, on the average. On the basis of current knowledge this is equivalent to an annual effective dose equivalent of 800 mu Sv. This compares with the overall average of the effective dose equivalent from natural radiation of almost 1900 mu Sv in a year. The distribution of exposures to the short-lived daughters of 222Rn is markedly skew and indicates that some dwellings support concentrations of these daughters leading to exposures in excess of 1 WLM in a year. The areas of the U.K. in which exposures above this level are most likely to occur are regions with enhanced uranium mineralisation. These areas are sparsely populated and high exposures here do not significantly affect the overall average exposure of the population to radon daughters. An intensive survey of radon and radon daughters concentrations in one predominantly igneous region is reported. The average exposure for the 250 dwellings in this region surveyed so far was estimated to be 1.3 WLM in a year, a factor of 8 greater than the national value. About 5% of the homes exceed 5 WLM in a year. Measurements of equilibrium factor indicate that plate-out contributes to the removal of radon daughters from room air. In general, the equilibrium factor measured indicates an unattached fraction of 218Po of less than 10%.