Risk Factors For Transmission Research Articles

Altered expression of endosomal Toll-like receptors and HBeAg seropositivity may act synergistically towards the vertical transmission of HBV.

Hepatitis B is one of the leading causes of mortality in India. Despite the mass vaccination programme, the burden of the infection is still increasing due to its vertical transmission. Asymptomatic nature of hepatitis B virus (HBV) infection owing to immune tolerance among pregnant women is a major issue in this regard. As such, this study aims to investigate the potential role of altered Toll-like receptor (TLR) expression (TLR-3, 7 and 9) along with peripheral blood HBeAg status in attaining differential cord blood (CB) HBV DNA status. Expression analysis reveals an overall downregulation of expression with mean±SD value 1.14±1.05, 0.86±0.5 and 0.71±0.4 (TLR 3, 7 and 9, respectively) upon comparison with healthy women. Further stratification based on CB HBV DNA status; the downregulation of expression was found to be significantly (p<.05) associated with positive CB HBV DNA status apart from peripheral HBeAg status. One hundred percent HBeAg positive parturiting women exhibit positive CB HBV DNA. Pearson's correlation analysis reveals a positive correlation between CB HBV DNA status and altered TLR expression, HBeAg status and mother HBV DNA status and as such can be associated with the potential risk of HBV vertical transmission. This study suggests that the downregulation of TLR 3, 7 and 9 may be a risk factor for potential vertical transmission of HBV.

A cross-sectional study of Angiostrongylus malaysiensis in rats and gastropod hosts from recreational parks in Kuala Lumpur, Malaysia: Detection, risk factors and pathology.

Angiostrongylus malaysiensis is a potential zoonotic parasite, which reported to co-occur with A. cantonensis in human cerebrospinal fluid. It is a heteroxenous nematode that primarily develops through the early larval stages in gastropods and attains sexual maturity within rats. This study was conducted to determine the host species responsible for the reservoir of A. malaysiensis and investigate the risk factor for transmission among the hosts in Kuala Lumpur, Malaysia. Sampling was conducted in six recreational parks. The rats were trapped alive using steel wire traps with bait, while the gastropods were collected by active searching. The rats were euthanized and dissected to collect any adult worms observed. The molecular detection of A. malaysiensis was performed by PCR on gastropod tissue samples. Biotic and landscape factors were recorded for risk factor analysis. In total, 82 rats and 330 gastropods were collected throughout the study. Overall, 3.64% of gastropods and 32.9% of rats were infected with A. malaysiensis. Rattus tiomanicus (Malayan wood rat) and Parmarion martensi (Yellow-shelled semi-slug) were found as important hosts for A. malaysiensis. Host species, sampling site and macrohabitat type are risk factors associated with the prevalence of A. malaysiensis infection in rats. For gastropods, host species and sampling site are risk factors that correlate with the parasite detection. In total, 128 adult A. malaysiensis were recovered from the infected rats. The mean intensity of infection with adult A. malaysiensis was 4.65 for Rattus rattus complex and 4.90 for R. tiomanicus. Adult worms were found in the pulmonary artery or right ventricle, while eggs and first-stage larvae were found in capillaries of the caudal lung lobe. Infected lungs showed extravasated red blood cells in the alveolar spaces. The pulmonary arteries in the infected lung lobe were thickened. Kepong Metropolitan Park is the hotspot area for A. malaysiensis in Kuala Lumpur. These results provide essential information for public health officials to develop targeted interventions to reduce the transmission of A. malaysiensis in urban areas, particularly in recreational parks.

The devastating effect of cyclone Freddy amidst the deadliest cholera outbreak in Malawi: a double burden for an already weak healthcare system-short communication.

Cholera outbreaks cause significant disease burden, especially in developing countries. While the disease is largely eliminated in developed countries, it still remains a huge burden to Sub-Saharan Africa. Lack of access to clean water, hygiene and sanitation facilities remains a huge risk factor for disease transmission and persistence. These outbreaks in Africa are usually associated with high case fatality rates. While many risk factors exist for the spread of the disease, climate change poses a huge challenge to the fight and spread of the disease. Most countries in southern Africa including Malawi and Mozambique have been experiencing the direct and indirect impact of climate change. Climate change can affect the epidemiological dynamics of multiple infectious agents, including vector-borne, water-borne, and food-borne pathogens. The aftermaths effects of flooding and droughts can largely be felt in seasonality changes in the spread of Cholera. Having an in-depth understanding of multiple factors that influence the patterns of spread of climate change related diseases combined with robust surveillance systems could help detect environmental changes in high-risk areas and result in early public health interventions that can alleviate potential outbreaks.

Association of Mycobacterium tuberculosis infection test results with risk factors for tuberculosis transmission

BackgroundClose contacts infected with Mycobacterium tuberculosis are at high risk of tuberculosis (TB) disease and a priority for preventive treatment. Three tests measure infection: two interferon-gamma release assays (IGRAs) and the tuberculin skin test (TST). The objective of our study was to assess the association of positive test results in contacts with infectiousness of the presumed TB source case. MethodsContacts in a cohort study at 10 United States sites received both IGRAs (QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB (T-SPOT)) and TST. We defined test conversion as negative for all tests at baseline and positive for at least one on retest. Risk ratios (RR) and 95% confidence intervals (CI) assessed association of positive test results with increased infectiousness of the TB case—defined as acid-fast bacilli (AFB) on sputum microscopy or cavities on chest radiographs— and contact demographics. ResultsAdjusted for contacts’ age, nativity, sex, and race, IGRAs (QFT-GIT RR = 6.1, 95% CI 1.7–22.2; T-SPOT RR = 9.4, 95% CI 1.1–79.1), but not TST (RR = 1.7, 95% CI 0.8–3.7), were more likely to convert among contacts exposed to persons with cavitary TB disease. ConclusionsBecause IGRA conversions in contacts are associated with infectiousness of the TB case, their use may improve efficiency of health department contact investigations by focusing efforts on those likely to benefit from preventive treatment in the United States.

Increasing Incidence and Risk Factors for Transmission of Covid-19 in Brebes Community Health Center, Indonesia

Background: Coronavirus Disease 2019 (COVID-19) is an infectious disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Now, COVID-19 is still a problem in Central Java. COVID-19 cases in Central Java rank third highest in Indonesia, one of which is Brebes Regency, where there have been confirmed cases leading to death, with the highest cases at the Brebes Community Health Center. Purpose: The purpose of the study was to determine the risk factors for the occurrence of COVID-19 in the work area of the Brebes CHC, Central Java. Method: This research is a quantitative study with an analytical observational design with a Cross-Sectional approach. The data is carried out by exclusion and inclusion criteria so that it is in accordance with the desired research focus. The sample in this study amounted to 78 respondents using purposive sampling. Data analysis was performed by univariate, bivariate (Chi-square test), and multivariate. Results: The results of this study were that gender, occupation, contact history, and habit of wearing masks had a significant relationship with COVID-19 cases, with a p-value of 0.046; 0.035; 0.019l; and 0.026, respectively. Meanwhile, education has no relationship with the incidence of COVID-19 (p-value = 0.379). Conclusion: To sum up, the risk factors for COVID-19 cases in the Brebes CHC area were gender, occupation, contact history, and habit of wearing masks. In controlling COVID-19, it is essential to apply the One-Health approach through cross-sector collaborations.&#x0D; &#x0D; Latar Belakang: Penyakit Coronavirus 2019 (COVID-19) adalah penyakit menular yang disebabkan oleh Sindrom Pernafasan Akut Parah Coronavirus 2 (SARS-CoV-2). Hingga saat ini, COVID-19 masih menjadi masalah di Jawa Tengah. Kasus COVID-19 di Jawa Tengah menduduki peringkat ketiga tertinggi di Indonesia salah satunya Kabupaten Brebes yang telah terkonfirmasi kasus meninggal dunia dengan kasus tertinggi di Puskesmas Brebes. Tujuan: Mengetahui faktor risiko terjadinya COVID-19 di wilayah kerja Puskesmas Brebes Jawa Tengah. Metode: Penelitian ini merupakan penelitian kuantitatif dengan desain observasional analitik dengan pendekatan Cross-Sectional. Sampel dalam penelitian ini berjumlah 78 responden dengan menggunakan random sampling. Analisis data dilakukan secara univariat, bivariat (uji Chi-square), dan multivariat. Hasil: Hasil penelitian ini adalah jenis kelamin, pekerjaan, riwayat kontak, dan kebiasaan memakai masker memiliki hubungan yang bermakna dengan kasus COVID-19, dengan p-value 0,046; 0,035; 0,019l; dan 0,026, masing-masing. Sedangkan pendidikan tidak ada hubungan dengan kejadian COVID-19 (p-value = 0,379). Simpulan: Faktor risiko kasus COVID-19 di wilayah Puskesmas Brebes adalah jenis kelamin, pekerjaan, riwayat kontak, dan kebiasaan memakai masker. Dalam pengendalian COVID-19, pendekatan One-Health perlu diterapkan melalui kolaborasi lintas sektor.

Outbreak Investigation of Typhoid Fever in the District of Gabes, South of Tunisia.

Typhoid fever is a significant public health concern in many parts of the world, particularly in developing countries with poor sanitation and hygiene conditions. In July 2016, an outbreak of typhoid fever occurred in Ghannouche, located in the south of Tunisia. This paper reports the results of a field investigation undertaken to identify possible transmission pathways and risk factors in order to propose control and preventive measures. A retrospective cohort study including a passive and active case finding, as well as an environmental and bacteriological investigation was conducted from July to September 2016. A case was defined as a person residing or having stayed in Ghannouche and having presented from the beginning of June clinical signs suggestive of typhoid fever, with, for a confirmed case, laboratory isolation of S.Tyhi, and for a probable case, an epidemiological link with a confirmed case. Attack rates were determined, and risk ratios were estimated with respect to exposures. Unadjusted and adjusted odds ratios were estimated using binary logistic regression. Among the 628 subjects investigated, 102 cases of typhoid fever were identified (74 confirmed and 28 probable) with an overall attack rate of 16.24%. Over 56% of cases were male and those under 10 years old were most affected (38.2%% of cases) with a median age of 12 years (interquartile range 5 to 25 years). The main clinical signs were fever (95%) and diarrhea (57%). Young age (adjusted OR = 0.95 and 95% CI = 0.93-0.97), low level of education (adjusted OR = 4.76 and 95% CI = 1.34-16.81), and the habitat type Arab or rudimentary house (adjusted OR = 4.93 and 95% CI = 2.61-8.27) were the socio-demographic factors independently associated with typhoid fever. Typhoid fever was found to be associated with drinking softened water (adjusted OR = 2.64 and 95% CI = 1.16-4.82), eating raw fruit and vegetables from family gardens (adjusted OR = 6.13 and 95% CI = 3.66-11.06), and using uncontrolled waste disposal (adjusted OR = 3.52 and 95% CI = 2.03-6.94). A total of 110 drinking water samples were analyzed; out of the 38 samples of softened water, 12 were non-compliant and 5 were positive for Salmonella. The screening activity identified two asymptomatic carriers, one of whom was a softened water seller. We concluded that drinking softened water from informal or unauthorized sale units, consuming fruit and vegetables from family gardens, uncontrolled dumping of household waste, and poor socio-economic conditions increase the risk of typhoid fever in this region. Many recommendations were implemented to stop this outbreak and to prevent further episodes.

Epidemiology of SARS-CoV-2 transmission and superspreading in Salt Lake County, Utah, March-May 2020.

Understanding the drivers of SARS-CoV-2 transmission can inform the development of interventions. We evaluated transmission identified by contact tracing investigations between March-May 2020 in Salt Lake County, Utah, to quantify the impact of this intervention and identify risk factors for transmission. RT-PCR positive and untested symptomatic contacts were classified as confirmed and probable secondary case-patients, respectively. We compared the number of case-patients and close contacts generated by different groups, and used logistic regression to evaluate factors associated with transmission. Data were collected on 184 index case-patients and up to six generations of contacts. Of 1,499 close contacts, 374 (25%) were classified as secondary case-patients. Decreased transmission odds were observed for contacts aged <18 years (OR = 0.55 [95% CI: 0.38-0.79]), versus 18-44 years, and for workplace (OR = 0.36 [95% CI: 0.23-0.55]) and social (OR = 0.44 [95% CI: 0.28-0.66]) contacts, versus household contacts. Higher transmission odds were observed for case-patient's spouses than other household contacts (OR = 2.25 [95% CI: 1.52-3.35]). Compared to index case-patients identified in the community, secondary case-patients identified through contract-tracing generated significantly fewer close contacts and secondary case-patients of their own. Transmission was heterogeneous, with 41% of index case-patients generating 81% of directly-linked secondary case-patients. Given sufficient resources and complementary public health measures, contact tracing can contain known chains of SARS-CoV-2 transmission. Transmission is associated with age and exposure setting, and can be highly variable, with a few infections generating a disproportionately high share of onward transmission.

Anopheles vector distribution and malaria transmission dynamics in Gbêkê region, central Côte d’Ivoire

BackgroundA better understanding of vector distribution and malaria transmission dynamics at a local scale is essential for implementing and evaluating effectiveness of vector control strategies. Through the data gathered in the framework of a cluster randomized controlled trial (CRT) evaluating the In2Care (Wageningen, Netherlands) Eave Tubes strategy, the distribution of the Anopheles vector, their biting behaviour and malaria transmission dynamics were investigated in Gbêkê region, central Côte d’Ivoire.MethodsFrom May 2017 to April 2019, adult mosquitoes were collected monthly using human landing catches (HLC) in twenty villages in Gbêkê region. Mosquito species wereidentified morphologically. Monthly entomological inoculation rates (EIR) were estimated by combining the HLC data with mosquito sporozoite infection rates measured in a subset of Anopheles vectors using PCR. Finally, biting rate and EIR fluctuations were fit to local rainfall data to investigate the seasonal determinants of mosquito abundance and malaria transmission in this region.ResultsOverall, Anopheles gambiae, Anopheles funestus, and Anopheles nili were the three vector complexes found infected in the Gbêkê region, but there was a variation in Anopheles vector composition between villages. Anopheles gambiae was the predominant malaria vector responsible for 84.8% of Plasmodium parasite transmission in the area. An unprotected individual living in Gbêkê region received an average of 260 [222–298], 43.5 [35.8–51.29] and 3.02 [1.96–4] infected bites per year from An. gambiae, An. funestus and An. nili, respectively. Vector abundance and malaria transmission dynamics varied significantly between seasons and the highest biting rate and EIRs occurred in the months of heavy rainfall. However, mosquitoes infected with malaria parasites remained present in the dry season, despite the low density of mosquito populations.ConclusionThese results demonstrate that the intensity of malaria transmission is extremely high in Gbêkê region, especially during the rainy season. The study highlights the risk factors of transmission that could negatively impact current interventions that target indoor control, as well as the urgent need for additional vector control tools to target the population of malaria vectors in Gbêkê region and reduce the burden of the disease.

Hyper-glycosylated N-linked site 339 of gp120 appears to be unique and may contribute to CRF01_AE transmission among men who have sex with men in China and Thailand.

HIV-1 CRF01_AE is one of the most important genotypes in China, especially in the population of men who have sex with men (MSM). It has become the most prevalent strain among them. Describing the variant characterization of CRF01_AE will help to reveal the reason behind its predominance in MSM. In the present study, the complete DNA sequences (CDSs) for gp120 from the envelope protein (env) gene of CRF01_AE in China and Thailand were retrieved from the Los Alamos HIV database. The CDSs for gp120 were divided into three subgroups according to the risk factors for HIV-1 transmission in a variety of populations, such as intravenous drug users (IDUs), heterosexual contacts (HCs), and MSM. The N-linked CDS glycosylation sites for gp120 in CRF01_AE were analyzed. The results showed a unique hyper-glycosylation site N-339 (refer to Hxb2) in the gp120 of CRF01_AE in MSM compared to the IDU and HC groups from China. The result was the same in the MSM group from Thailand, which suggests that the hyper-glycosylation site N-339 may explain the widespread CRF01_AE genotype in MSM.

Risk factors for COVID-19 outbreaks in livestock slaughtering and processing facilities in Republic of Korea.

The goal of this study was to help prevent and control the spread of coronavirus disease 2019 (COVID-19) by identifying transmission routes and risk factors in livestock slaughtering and processing facilities (SPFs) and establishing an optimal intervention strategy for outbreaks. This case series study was a demographic analysis of patients with confirmed COVID-19 associated with 5 SPFs in Korea between January and June 2021. Additionally, in a retrospective cohort study, the association between COVID-19 infection and risk factors was analyzed for SPFs at which outbreaks occurred. The COVID-19 attack rates were 11.2%, 24.5%, and 6.8% at 3 poultry SPFs (PSPFs) and 15.5% and 25.2% at 2 mammal SPFs (MSPFs). Regarding spatial risk factors, the COVID-19 risk levels were 12.1-, 5.2-, and 5.0-fold higher in the refrigeration/ freezing, by-product processing, and carcass cutting areas, respectively, than in the office area. The risk of COVID-19 infection was 2.1 times higher among employees of subcontractors than among employees of contractors. The COVID-19 risk levels were 5.3- and 3.0-fold higher in foreign workers than in native Korean workers in the PSPFs and MSPFs, respectively. As the COVID-19 pandemic continues, a detailed policy for infectious disease prevention and control intervention is needed, without interrupting economic activities. Thus, we propose an ideal intervention plan to prevent COVID-19 through disinfection and preemptive testing and to block its transmission through effective contact management during outbreaks at SPFs.

Vaccine effectiveness and the epidemiological characteristics of a COVID-19 outbreak in a tertiary hospital in Republic of Korea.

Healthcare facilities are high-risk sites for infection. This study analyzed the epidemiological characteristics of a coronavirus disease 2019 (COVID-19) outbreak in a tertiary hospital after COVID-19 vaccination had been introduced in Republic of Korea. Vaccine effectiveness (VE) and shared anti-infection strategies are also assessed. The risk levels for 4,074 contacts were evaluated. The epidemiological characteristics of confirmed cases were evaluated using the chi-square test. The "1 minus relative risk" method was used to determine VE in preventing infection, progression to severe disease, and death. In the largest affected area (the 8th floor), a separate relative risk analysis was conducted. A multivariate logistic regression analysis (with 95% confidence interval [CIs]) was used to identify transmission risk factors with a significance level <10% via the backward elimination method. In total, 181 cases of COVID-19 were confirmed, with an attack rate of 4.4%. Of those cases, 12.7% progressed to severe disease, and 8.3% died. In the cohort isolation area on the 8th floor, where 79.0% of the confirmed cases occurred, the adjusted odds ratio was 6.55 (95% CI, 2.99-14.33) and 2.19 (95% CI, 1.24-3.88) for caregivers and the unvaccinated group, respectively. VE analysis revealed that 85.8% of the cases that progressed to severe disease and 78.6% of the deaths could be prevented by administering a second vaccine. Caregiver training for infection prevention and control is necessary to reduce infection risk. Vaccination is an important intervention to reduce the risk of progression to severe disease and death.

Characterizing COVID-19 transmission risk factors among frontline health-care workers using the WHO risk assessment tool: insights from a tertiary care center in South India

Abstract Background The objective of this study was to assess the exposure risk factors for transmission of and subsequent infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (COVID-19) among the frontline health-care workers (HCWs) in a South Indian tertiary care center during the COVID-19 pandemic. Methods This retrospective, observational study was conducted over a period of 6 months, from June 2020 to November 2020. Participants included HCWs who completed a risk assessment to identify encounters with COVID-19-positive individuals using a modified World Health Organization COVID-19 risk assessment tool. Results A total of 4744 HCWs who had exposure to COVID-19-positive individuals were assessed during the study period. There were 942 (19.8%) participants identified as having had high-risk exposure and 3802 (80.2%) identified as having had low-risk exposure. There were 106 (2.2%) participants who became infected with COVID-19 during the surveillance period of 14 days; 4.8% of high risk and 1.5% of low risk tested positive. Among the HCWs working in high-risk COVID-19 areas, only one HCW had contracted the illness (N = 1, 0.9%). Shared spaces (70%) and infection protection and control breaches (66%) were found to be highly prevalent modes of exposure in the COVID-19-positive cohort. The attack rate among COVID-19 cluster groups (two or more confirmed or probable cases of COVID-19 who are linked by the same location of exposure) (5.5%) was higher than the attack rate (2.2%) noted among the total contacts screened, and no significant association was observed between risk categories in the clustered groups. Conclusion This study highlights higher risk of COVID-19 positivity among high-risk contacts as compared to low-risk contacts.

Infection rate among close contacts of patients with coronavirus disease in Japan: a descriptive study and literature review.

In Japan, on April 20, 2020, the definition of a close contact regarding coronavirus disease (COVID-19) was changed from a long-term contact time to a specified contact time of 15 min and from a contact distance of 2 m to 1 m. We aimed to determine the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rate among close contacts of patients with COVID-19 and determine the impact of the infection on transmission among close contacts. The numbers of SARS-CoV-2 tests, SARS-CoV-2-positive cases, and close contacts of patients with COVID-19 were assessed between March 2020 and February 2021 in Fukui Prefecture, Japan. The study period was subdivided into 3 periods. The second and third period contained data with the changed definition of close contact. Overall, 32,238 SARS-CoV-2 tests were performed. There were 545 patients with COVID-19 and 1487 close contacts, of whom 267 tested positive. The highest infection rate occurred in period 3. Distance, protective measures, and contact time with COVID-19 patients influenced the increased infection rate. The infection rate showed a rising trend from 11.1% in period 1 to 19.2% and 20.0% in periods 2 and 3, respectively (Cochran-Armitage test; P < 0.004). Multivariate analysis revealed that female sex was an independent risk factor for infection of close contacts (odds ratio: 2.23; 95% confidence interval: 1.700-2.930). Female sex is a risk factor for transmission by close contacts. The rate of infection among close contacts may be associated with contact time, contact distance, and protective measures.

Evaluation of four environmental sampling methods for the recovery of multidrug-resistant organisms

Background: Environmental contamination is a major risk factor for multidrug-resistant organism (MDRO) exposure and transmission in the healthcare setting. Sponge-stick sampling methods have been developed and validated for MDRO epidemiological investigations, leading to their recommendation by public health agencies. However, similar bacteriological yields with more readily available methods that require less processing time or specialized equipment have also been reported. We compared the ability of 4 sampling methods to recover a variety of MDRO taxa from a simulated contaminated surface. Methods: We assessed the ability of (1) cotton swabs moistened with phosphate buffer solution (PBS), (2) e-swabs moistened with e-swab solution, (3) cellulose-containing sponge sticks (CSS), and (4) non–cellulose-containing sponge sticks (NCS) to recover extended-spectrum β-lactamase (ESBL)–producing Escherichia coli, carbapenem-resistant Pseudomonas aeruginosa (CRPA), carbapenem-resistant Acinetobacter baumannii (CRAB), methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), and a mixture that contained VRE, MRSA, and ESBL organisms. A solution of known bacterial inoculum (~105 CFU/mL) was made for each MDRO. Then, 1 mL solution was pipetted on a stainless-steel surface (8 × 12 inch) in 5 µL dots and allowed to dry for 1 hour. All samples were collected by 1 individual to minimize variation in technique. Sponge sticks were expressed in PBS containing 0.02% Tween 80 using a stomacher, were centrifuged, and were then resuspended in PBS. Cotton and e-swabs were spun in a vortexer. Then, 1 mL of fluid from each method was plated to selective and nonselective media in duplicate and incubated at 35°C for 24 hours (MRSA plates, 48 hours) (Fig. 1). CFU per square inch and percentage recovery were calculated. Results: Table 1 shows the CFU per square inch and percentage recovery for each sampling method–MDRO taxa combination. The percentage recovery varied across MDRO taxa. Across all methods, the lowest rate of recovery was for CRPA and the highest was for VRE. Regardless of MDRO taxa, the percentage recovery was highest for the sponge stick (CSS and NCS) compared to swab (cotton and E-swab) methods across all taxa (Table 1 and Fig. 2).Conclusions: These findings support the preferential use of sponge sticks for the recovery of MDROs from the healthcare environment, despite the additional processing and equipment time needed for sponge sticks. Further studies are needed to assess the robustness of these findings in noncontrived specimens as well as the comparative effectiveness of different sampling methods for non–culture-based MDRO detection.Disclosure: None

The Role of Wildlife and Pests in the Transmission of Pathogenic Agents to Domestic Pigs: A Systematic Review.

Wild animals and pests are important reservoirs and vectors of pathogenic agents that can affect domestic pigs. Rapid globalization, anthropogenic factors, and increasing trends toward outdoor pig production facilitate the contact between domestic pigs and wildlife. However, knowledge on the transmission pathways between domestic pigs and the aforementioned target groups is limited. The present systematic review aims to collect and analyze information on the roles of different wild animal species and pests in the spread of pathogens to domesticated pigs. Overall, 1250 peer-reviewed manuscripts published in English between 2010 and 2022 were screened through the PRISMA framework using PubMed, Scopus, and Web of Science databases. A total of 84 studies reporting possible transmission routes of different pathogenic agents were included. A majority of the studies (80%) focused on the role of wild boars in the transmission of pathogenic agents to pig farms. Studies involving the role of rodents (7%), and deer (6%) were the next most frequent, whereas the role of insects (5%), wild carnivores (5%), wild birds (4%), cats (2%), and badgers (1%) were less available. Only 3.5% of studies presented evidence-based transmission routes from wildlife to domestic pigs. Approximately 65.5% of the included studies described possible risks/risk factors for pathogens' transmission based on quantitative data, whereas 31% of the articles only presented a hypothesis or qualitative analysis of possible transmission routes or risk factors and/or contact rates. Risk factors identified include outdoor farms or extensive systems and farms with a low level of biosecurity as well as wildlife behavior; environmental conditions; human activities and movements; fomites, feed (swill feeding), water, carcasses, and bedding materials. We recommend the strengthening of farm biosecurity frameworks with special attention to wildlife-associated parameters, especially in extensive rearing systems and high-risk zones as it was repeatedly found to be an important measure to prevent pathogen transmission to domestic pigs. In addition, there is a need to focus on effective risk-based wildlife surveillance mechanisms and to raise awareness among farmers about existing wildlife-associated risk factors for disease transmission.

Duration of Contact on Pulmonary Tb Transmission: Case Study - Control

The Ambon City Health Office, through the Prevention and Control of Infectious Diseases, pointed out that the number of new TB cases in Ambon City in the last three years has tended to increase, where in 2020 the number of cases was 716, in 2021 there were 961 and in 2022 there were 1,296 sufferers. with the number of deaths of 32 people in 2020, in 2022 and 2023 each of 23 people. This study used an analytic observational study with a case control study design, designed to determine the risk and the effect of exposure duration on pulmonary TB transmission with a total sample of 72, bivariate analysis using the chi square test and calculating the odds ratio (OR). multivariate analysis using binary logistic regression test. The results of the study found that close contact is a risk factor for TB transmission with OR = 4.857; contact time is a risk factor for TB transmission with OR = 6.143; and length of contact are risk factors for TB transmission with OR = 5.857. The binary logistic regression equation shows that someone who lives in the same house with a patient with pulmonary tuberculosis, exposure time &gt; 8 hours/day and contact duration &gt; 6 months, has a probability of suffering from pulmonary TB by 30% compared to someone without risk factors. In conclusion, the closeness of contact, contact time and duration of contact are risk factors for pulmonary TB transmission.

Hepatitis B Surface Antigen (HbsAg) Prevalence and Risk Factors in Women of Childbearing Age in Eastern Algeria

Background: Hepatitis B is the most common chronic viral infection and a significant contributor to morbidity and death globally. Based on the mother's hepatitis B e antigen (HBeAg) status, the probability of perinatal HBV infection in children delivered to mothers with HBV ranges from 10% to 85%.Aim: to determine the prevalence of hepatitis B virus infection among women of childbearing age in the eastern region of Algeria and investigate risk factors for infection to recommend ways to reduce the disease's impact on neonatal morbidity and mortality.Methods: We conducted a cross-sectional study in Sétif, Algeria, from 2005 to 2007 to assess the prevalence of Hepatitis B Surface Antigen among women of childbearing age. This study is the first and only one in Algeria. Data on risk factors, obstetrics, and sociodemographic were gathered using structured questionnaire; they were subsequently tested using an enzymelinked immunosorbent assay for HBsAg. The data collected were entered and processed using Epi info 3.3.2 software. Infection prevalence, sociodemographic, clinical, obstetric and risk factors variable frequency distributions were calculated. The student's t-test and Fisher's exact test were applied, at a significance level of 5%.Results: There are834 women of childbearing age's medical records were examined for this study. 1% of HBsAg test findings were positive. Positive HBsAg didn't significantly correlate with any other variables, including age, place of residence, municipality, marital status, occupation, parity, current pregnancy, reason for current consultation, transmission risk factors (blood transfusion, recent piercing, dental care, shared personal hygiene equipment, injection with multiple use equipment, tattoo, scarification, partner characteristics). However, history of jaundice has a significant protective effect against HBsAg positive.Conclusion: Although our results classify the two municipalities studied as low prevalence areas (&lt; 2%). Prenatal HBsAg screening is strongly advised.

High-sensitivity HBV DNA test for the diagnosis of occult HBV infection: commonly used but not reliable.

Occult hepatitis B virus (HBV) infection (OBI) is a condition in which replication-competent viral DNA is detected in the liver (with detectable or undetectable HBV DNA in serum) of individual testing negative for HBV surface antigen (HBsAg). It is a risk factor for transfusion or transplant transmission, reactivation after immunosuppression or chemotherapy, and progression of chronic liver disease and hepatocarcinogenesis. The long-term stable presence of covalently closed circular DNA (cccDNA), which is fully replicative in the nucleus of infected hepatocytes is the molecular basis for the formation of OBI. HBV genome in liver tissue, HBV DNA and anti-HBc test in serum are the gold standard, common method and alternative markers for OBI diagnosis, respectively. Due to the stability of covalently closed circular DNA (cccDNA) and the long half-life of hepatocytes, the existence of OBI is extensive and prolonged. The low and/or intermittent replication of HBV in OBI patients, the limitations of the sensitivity of serological tests, and the non-standardized and invasive nature of liver histology render the "commonly used" serological tests are unreliable and the "gold standard" liver histology is impractical, thus the findings from studies on the formation, diagnosis and transplantation or transfusion transmission of HBV in OBI strongly suggest that the "alternative" marker, the anti-HBc test, may be the most reliable and practical approach for OBI diagnosis.

Genomic surveillance identifies potential risk factors for SARS-CoV-2 transmission at a mid-sized university in a small rural town

Understanding transmission dynamics of SARS-CoV-2 in institutions of higher education (IHEs) is important because these settings have potential for rapid viral spread. Here, we used genomic surveillance to retrospectively investigate transmission dynamics throughout the 2020–2021 academic year for the University of Idaho (“University”), a mid-sized IHE in a small rural town. We generated genome assemblies for 1168 SARS-CoV-2 samples collected during the academic year, representing 46.8% of positive samples collected from the University population and 49.8% of positive samples collected from the surrounding community (“Community”) at the local hospital during this time. Transmission dynamics differed for the University when compared to the Community, with more infection waves that lasted shorter lengths of time, potentially resulting from high-transmission congregate settings along with mitigation efforts implemented by the University to combat outbreaks. We found evidence for low transmission rates between the University and Community, with approximately 8% of transmissions into the Community originating from the University, and approximately 6% of transmissions into the University originating from the Community. Potential transmission risk factors identified for the University included congregate settings such as sorority and fraternity events and residences, holiday travel, and high caseloads in the surrounding community. Knowledge of these risk factors can help the University and other IHEs develop effective mitigation measures for SARS-CoV-2 and similar pathogens.

Risk factors associated with indoor transmission during home quarantine of COVID-19 patients.

The study aimed to identify potential risk factors for family transmission and to provide precautionary guidelines for the general public during novel Coronavirus disease 2019 (COVID-19) waves. A retrospective cohort study with numerous COVID-19 patients recruited was conducted in Shanghai. Epidemiological data including transmission details, demographics, vaccination status, symptoms, comorbidities, antigen test, living environment, residential ventilation, disinfection and medical treatment of each participant were collected and risk factors for family transmission were determined. A total of 2,334 COVID-19 patients participated. Compared with non-cohabitation infected patients, cohabitated ones were younger (p = 0.019), more commonly unvaccinated (p = 0.048) or exposed to infections (p < 0.001), and had higher rates of symptoms (p = 0.003) or shared living room (p < 0.001). Risk factors analysis showed that the 2019-nCov antigen positive (OR = 1.86, 95%CI 1.40-2.48, p < 0.001), symptoms development (OR = 1.86, 95%CI 1.34-2.58, p < 0.001), direct contact exposure (OR = 1.47, 95%CI 1.09-1.96, p = 0.010) were independent risk factors for the cohabitant transmission of COVID-19, and a separate room with a separate toilet could reduce the risk of family transmission (OR = 0.62, 95%CI 0.41-0.92, p = 0.018). Patients showing negative 2019-nCov antigen tests, being asymptomatic, living in a separate room with a separate toilet, or actively avoiding direct contact with cohabitants were at low risk of family transmission, and the study recommended that avoiding direct contact and residential disinfection could reduce the risk of all cohabitants within the same house being infected with COVID-19.