Middle East respiratory syndrome (MERS), a highly lethal respiratory disease caused by a novel coronavirus (MERS-CoV), is an emerging disease with high potential for epidemic spread. It has been ...listed by the WHO and the Coalition for Epidemic Preparedness Innovations (CEPI) as an important target for vaccine development. While initially the majority of MERS cases were hospital acquired, continued emergence of MERS is attributed to community acquisition, with camels likely being the direct or indirect source. However, the majority of patients do not describe camel exposure, making the route of transmission unclear. Here, using sensitive immunological assays and a cohort of camel workers (CWs) with well-documented camel exposure, we show that approximately 50% of camel workers (CWs) in the Kingdom of Saudi Arabia (KSA) and 0% of controls were previously infected. We obtained blood samples from 30 camel herders, truck drivers, and handlers with well-documented camel exposure and from healthy donors, and measured MERS-CoV-specific enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay (IFA), and neutralizing antibody titers, as well as T cell responses. Totals of 16/30 CWs and 0/30 healthy control donors were seropositive by MERS-CoV-specific ELISA and/or neutralizing antibody titer, and an additional four CWs were seronegative but contained virus-specific T cells in their blood. Although virus transmission from CWs has not been formally demonstrated, a possible explanation for repeated MERS outbreaks is that CWs develop mild disease and then transmit the virus to uninfected individuals. Infection of some of these individuals, such as those with comorbidities, results in severe disease and in the episodic appearance of patients with MERS.
The Middle East respiratory syndrome (MERS) is a coronavirus (CoV)-mediated respiratory disease. Virus transmission occurs within health care settings, but cases also appear sporadically in the community. Camels are believed to be the source for community-acquired cases, but most patients do not have camel exposure. Here, we assessed whether camel workers (CWs) with high rates of exposure to camel nasal and oral secretions had evidence of MERS-CoV infection. The results indicate that a high percentage of CWs were positive for virus-specific immune responses but had no history of significant respiratory disease. Thus, a possible explanation for repeated MERS outbreaks is that CWs develop mild or subclinical disease. These CWs then transmit the virus to uninfected individuals, some of whom are highly susceptible, develop severe disease, and are detected as primary MERS cases in the community.
Understanding the immune response to Middle East respiratory syndrome coronavirus (MERS-CoV) is crucial for disease prevention and vaccine development. We studied the antibody responses in 48 human ...MERS-CoV infection survivors who had variable disease severity in Saudi Arabia. MERS-CoV-specific neutralizing antibodies were detected for 6 years postinfection.
The first incidence of acquired immunodeficiency syndrome (AIDS) from the Kingdom of Saudi Arabia (KSA) was reported back in 1984, and by the end of 2013, around 1509 patients were diagnosed with HIV ...infection. Recently in 2018, the Saudi ministry of health released that the incidence of HIV in Saudi Arabia is 3 cases of HIV for every 10,000 of the population. Having said that, the surveillance of HIV will face a range of challenges in KSA despite proper medical care, counseling, family planning, diagnostic, evaluation, and the use of effective anti-retroviral therapy. Patients who underwent anti-retroviral therapy showed significant reduction in morbidity as well as mortality. On the other hand, further targeted treatment and preventive strategies are warranted to control HIV co-infections in the KSA. In addition, progress towards meeting the WHO 90-90-90 goals for HIV not only at KSA but at the MENA region too, which is that of the population, 90% are diagnosed, 90% undergoing treatment, and 90% under viral control, is not being systematically monitored. In this review, we discuss the common co-infections with HIV infections that are reported in KSA, which when compared to international trends, it is similar for both viral hepatitis and tuberculosis. Although those co-infections exist, they are presented in different ratios and percentages when compared to the international reported data. These differences mandates defining and introducing new resilient methods of treatment and preventive measures. In this review, we offer an insight into healthcare policymakers to be compliant with UNAIDS 2020 vision program. We also discuss some of the gaps and recommendations to achieve the WHO 90-90-90 goal.
•The de-isolation of immunocompromised COVID-19 patients is challenging.•A test-based rather than symptom-based approach is suggested.•The mean Ct value for negative viral cultures was 20.5 in this ...case series.•A test-based approach could lead to prolonged quarantine of non-infectious patients.•The de-isolation of immunocompromised patients needs disease-specific studies.
Immunocompromised patients with coronavirus disease 2019 (COVID-19) have prolonged infectious viral shedding for more than 20 days. A test-based approach is suggested for de-isolation of these patients.
The strategy was evaluated by comparing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load (cycle threshold (Ct) values) and viral culture at the time of hospital discharge in a series of 13 COVID-19 patients: six immunocompetent and seven immunocompromised (five solid organ transplant patients, one lymphoma patient, and one hepatocellular carcinoma patient).
Three of the 13 (23%) patients had positive viral cultures: one patient with lymphoma (on day 16) and two immunocompetent patients (on day 7 and day 11). Eighty percent of the patients had negative viral cultures and had a mean Ct value of 20.5. None of the solid organ transplant recipients had positive viral cultures.
The mean Ct value for negative viral cultures was 20.5 in this case series of immunocompromised patients. Unlike those with hematological malignancies, none of the solid organ transplant patients had positive viral cultures. Adopting the test-based approach for all immunocompromised patients may lead to prolonged quarantine. Large-scale studies in disease-specific populations are needed to determine whether a test-based approach versus a symptom-based approach or a combination is applicable for the de-isolation of various immunocompromised patients.
Summary
The increasing global prevalence of SARS‐CoV‐2 and the resulting COVID‐19 disease pandemic pose significant concerns for clinical management of solid organ transplant recipients (SOTR). ...Wearable devices that can measure physiologic changes in biometrics including heart rate, heart rate variability, body temperature, respiratory, activity (such as steps taken per day) and sleep patterns, and blood oxygen saturation show utility for the early detection of infection before clinical presentation of symptoms. Recent algorithms developed using preliminary wearable datasets show that SARS‐CoV‐2 is detectable before clinical symptoms in >80% of adults. Early detection of SARS‐CoV‐2, influenza, and other pathogens in SOTR, and their household members, could facilitate early interventions such as self‐isolation and early clinical management of relevant infection(s). Ongoing studies testing the utility of wearable devices such as smartwatches for early detection of SARS‐CoV‐2 and other infections in the general population are reviewed here, along with the practical challenges to implementing these processes at scale in pediatric and adult SOTR, and their household members. The resources and logistics, including transplant‐specific analyses pipelines to account for confounders such as polypharmacy and comorbidities, required in studies of pediatric and adult SOTR for the robust early detection of SARS‐CoV‐2, and other infections are also reviewed.
Complement protein C1q, the recognition molecule of the classical pathway, performs a diverse range of complement and non-complement functions. It can bind various ligands derived from self, ...non-self, and altered self and modulate the functions of immune and non-immune cells including dendritic cells and microglia. C1q involvement in the clearance of apoptotic cells and subsequent B cell tolerance is more established now. Recent evidence appears to suggest that C1q plays an important role in pregnancy where its deficiency and dysregulation can have adverse effects, leading to preeclampsia, missed abortion, miscarriage or spontaneous loss, and various infections. C1q is also produced locally in the central nervous system, and has a protective role against pathogens and possible inflammatory functions while interacting with aggregated proteins leading to neurodegenerative diseases. C1q role in synaptic pruning, and thus CNS development, its anti-cancer effects as an immune surveillance molecule, and possibly in aging are currently areas of extensive research.
Surfactant protein D (SP-D) is a soluble C-type lectin, belonging to the collectin (collagen-containing calcium-dependent lectin) family, which acts as an innate immune pattern recognition molecule ...in the lungs at other mucosal surfaces. Immune regulation and surfactant homeostasis are salient functions of SP-D. SP-D can bind to a range of viral, bacterial, and fungal pathogens and trigger clearance mechanisms. SP-D binds to gp120, the envelope protein expressed on HIV-1, through its C-type lectin or carbohydrate recognition domain. This is of importance since SP-D is secreted by human mucosal epithelial cells and is present in the female reproductive tract, including vagina. Another C-type lectin, dendritic cell (DC)-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN), present on the surface of the DCs, also binds to HIV-1 gp120 and facilitates viral transfer to the lymphoid tissues. DCs are also present at the site of HIV-1 entry, embedded in vaginal or rectal mucosa. In the present study, we report a direct protein-protein interaction between recombinant forms of SP-D (rfhSP-D) and DC-SIGN
their C-type lectin domains. Both SP-D and DC-SIGN competed for binding to immobilized HIV-1 gp120. Pre-incubation of human embryonic kidney cells expressing surface DC-SIGN with rfhSP-D significantly inhibited the HIV-1 transfer to activated peripheral blood mononuclear cells.
analysis revealed that SP-D and gp120 may occupy same sites on DC-SIGN, which may explain the reduced transfer of HIV-1. In summary, we demonstrate, for the first time, that DC-SIGN is a novel binding partner of SP-D, and this interaction can modulate HIV-1 capture and transfer to CD4
T cells. In addition, the present study also reveals a novel and distinct mechanism of host defense by SP-D against HIV-1.
The ability to screen environmental water samples for gastroenteritis pathogens, particularly viruses remains challenging. Here, we investigated the presence of enteric viruses in treated sewage ...effluent water samples collected from a cooling tower in The Kingdom of Saudi Arabia (SA) from 2018 to 2019. Our ultimate aim was to determine the optimal handling and processing conditions for the water samples and the most sensitive detection method for the assessment of viral contamination. Sewage was collected before and after treatment at three defined zones. Samples were concentrated by ultracentrifugation and analyzed using a multiplexed bead-based assay system (Luminex technology) or multiplex PCR (QIAstat-Dx). The efficiency of these modalities to accurately detect virus contamination were subsequently compared. In total, 64 samples (16 controls and four treated samples per-control) were analyzed for 26 enteric pathogens. Of the samples, 98.7% were negative for viruses following treatment. Detection rates were higher for the multiplex PCR (QIAstat-Dx) system compared to the hybridization method, highlighting its higher sensitivity. The current water sewage treatment protocols in KSA could efficiently eradicate viral pathogens, minimizing their potential for waterborne transmission. We provide the first systematic analysis of two molecular detection methods for the assessment of gastroenteritis-associated pathogens from environmental samples in KSA. We conclude that the multiplex PCR (QIAstat-Dx) system outperforms the Luminex technology for the detection of virus pathogens in treated water samples.
Measles is an RNA virus infectious disease mainly seen in children. Despite the availability of an effective vaccine against measles, it remains a health issue in children. Although it is a ...self-limiting disease, it becomes severe in undernourished and immune-compromised individuals. Measles infection is associated with secondary infections by opportunistic bacteria due to the immunosuppressive effects of the measles virus. Recent reports highlight that measles infection erases the already existing immune memory of various pathogens. This review covers the incidence, pathogenesis, measles variants, clinical presentations, secondary infections, elimination of measles virus on a global scale, and especially the immune responses related to measles infection.
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