Spatiotemporal Changes in Plasmodium vivax msp142 Haplotypes in Southern Mexico: From the Control to the Pre-Elimination Phase

For 20 years, Plasmodium vivax has been the only prevalent malaria species in Mexico, and cases have declined significantly and continuously. Spatiotemporal genetic studies can be helpful for understanding parasite dynamics and developing strategies to weaken malaria transmission, thus facilitating the elimination of the parasite. The aim of the current contribution was to analyze P. vivax-infected blood samples from patients in southern Mexico during the control (1993–2007) and pre-elimination phases (2008–2011). Nucleotide and haplotype changes in the pvmsp142 fragment were evaluated over time. The majority of multiple genotype infections occurred in the 1990s, when the 198 single nucleotide sequences exhibited 57 segregating sites, 64 mutations, and 17 haplotypes. Nucleotide and genetic diversity parameters showed subtle fluctuations from across time, in contrast to the reduced haplotype diversity and the increase in the R2 index and Tajima’s D value from 2008 to 2011. The haplotype network consisted of four haplogroups, the geographical distribution of which varied slightly over time. Haplogroup-specific B-cell epitopes were predicted. Since only high-frequency and divergent haplotypes persisted, there was a contraction of the parasite population. Given that 84% of haplotypes were exclusive to Mesoamerica, P. vivax flow is likely circumscribed to this region, representing important information for parasite surveillance.

A Role for B Cells to Transmit Hepatitis C Virus Infection

Hepatitis C virus (HCV) is highly variable and transmits through infected blood to establish a chronic liver infection in the majority of patients. Our knowledge on the infectivity of clinical HCV strains is hampered by the lack of in vitro cell culture systems that support efficient viral replication. We and others have reported that HCV can associate with and infect immune cells and may thereby evade host immune surveillance and elimination. To evaluate whether B cells play a role in HCV transmission, we assessed the ability of B cells and sera from recent (<2 years) or chronic (≥ 2 years) HCV patients to infect humanized liver chimeric mice. HCV was transmitted by B cells from chronic infected patients whereas the sera were non-infectious. In contrast, B cells from recently infected patients failed to transmit HCV to the mice, whereas all serum samples were infectious. We observed an association between circulating anti-glycoprotein E1E2 antibodies and B cell HCV transmission. Taken together, our studies provide evidence for HCV transmission by B cells, findings that have clinical implications for prophylactic and therapeutic antibody-based vaccine design.

Anti-prothrombin autoantibodies enriched after infection with SARS-CoV-2 and influenced by strength of antibody response against SARS-CoV-2 proteins

Antiphospholipid antibodies (aPL), assumed to cause antiphospholipid syndrome (APS), are notorious for their heterogeneity in targeting phospholipids and phospholipid-binding proteins. The persistent presence of Lupus anticoagulant and/or aPL against cardiolipin and/or β2 glycoprotein I have been shown to be independent risk factors for vascular thrombosis and pregnancy morbidity in APS. aPL production is thought to be triggered by–among other factors–viral infections, though infection-associated aPL have mostly been considered non-pathogenic. Recently, the potential pathogenicity of infection-associated aPL has gained momentum since an increasing number of patients infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been described with coagulation abnormalities and hyperinflammation, together with the presence of aPL. Here, we present data from a multicentric, mixed-severity study including three cohorts of individuals who contracted SARS-CoV-2 as well as non-infected blood donors. We simultaneously measured 10 different criteria and non-criteria aPL (IgM and IgG) by using a line immunoassay. Further, IgG antibody response against three SARS-CoV-2 proteins was investigated using tripartite automated blood immunoassay technology. Our analyses revealed that selected non-criteria aPL were enriched concomitant to or after an infection with SARS-CoV-2. Linear mixed-effects models suggest an association of aPL with prothrombin (PT). The strength of the antibody response against SARS-CoV-2 was further influenced by SARS-CoV-2 disease severity and sex of the individuals. In conclusion, our study is the first to report an association between disease severity, anti-SARS-CoV-2 immunoreactivity, and aPL against PT in patients with SARS-CoV-2.

Knowledge, attitude and behavior study on HIV awareness among continuous rotatory residential interns and postgraduates

<p class="abstract"><strong>Background:</strong> Human immunodeficiency virus (HIV) that leads to Acquired immunodeficiency syndrome (AIDS) is transmitted mainly by sexual contact and exposure to infected blood. Healthcare workers (HCWs) such as Continuous rotatory residential interns (CRRIs) and postgraduates are at risk of acquiring HIV infection, primarily due to exposure to infected blood. The chances of infection depend on occupation, procedures performed, and use of preventive measures. The aim of the study was to access and compare knowledge, attitude and behavior about HIV awareness among CRRIs and Postgraduates.</p><p class="abstract"><strong>Methods:</strong> A cross sectional survey of 80 CRRIs and 80 postgraduates from Sree Balaji Medical College and Hospital was taken. A self-administered questionnaire was made and information regarding age, gender, knowledge about HIV, attitude and behavior towards HIV positive individual was gathered and compared between CRRIs and postgraduates. The data was compared and analyzed.<strong></strong></p><p class="abstract"><strong>Results:</strong> The results of the study revealed that postgraduates had better knowledge about routes of transmission of HIV compared to CRRIs. However, knowledge about preventive guidelines, vaccines and prophylaxis have to be improved by both postgraduates and CRRIs. Attitude towards HIV affected individual was positive. Behavior and practices followed to prevent HIV transmission have to be improved.</p><p class="abstract"><strong>Conclusions:</strong> HIV is an occupational hazard among HCWs. Appropriate knowledge about HIV is important. Attitude towards HIV infected individual plays an important role as it determines the care of the patient. Practicing standard guidelines while phlebotomy prevents the infection.</p>

The Extrinsic Incubation Period of Zika Virus in Florida Mosquitoes Aedes aegypti and Ae. albopictus

The Asian genotype of Zika virus (ZIKV) emerged in Brazil in 2015 and subsequently spread throughout the Americas. In July 2016, Florida experienced its first locally acquired ZIKV infection in the continental U.S. Concerns about health risks from ZIKV infection have increased the need to investigate the interactions between potential mosquito vectors and ZIKV. The time it takes for an arbovirus to propagate within a mosquito, and become transmissible, is the extrinsic incubation period (EIP). The EIP for potential mosquito vectors in Florida is unknown. To address this gap in the understanding of ZIKV epidemiology, Florida Aedes aegypti (L.) and Ae. albopictus (Skuse) were orally exposed to ZIKV infected blood meals and fully engorged mosquitoes were held at a constant temperature of 28 °C through the duration of the experiment. Saliva expectorates were collected from cohorts of mosquitoes and tested for the presence of ZIKV at three-day intervals over a period of 24 days to allow for an evaluation of the EIP of the emergent Asian lineage of ZIKV. High rates of infected bodies in Ae. albopictus (75–94%) and Ae. aegypti (68–86%) were observed throughout the incubation period, which did not differ by species. Higher rates of disseminated infection were observed later during the incubation period but did not differ between species. We calculated the 50% EIP to be shorter in Ae. albopictus than Ae. aegypti (16.2 and 18.2 days post infection, respectively). The competence for ZIKV observed in both species may contribute to high rates of ZIKV transmission in Florida populations.

Assessment of hepatitis B surface antigen negative blood units for HBV DNA among replacement blood donors in a hospital based blood bank in Nigeria

Background: Hepatitis B virus infection is one of the greatest threats to blood safety all over the world. The laboratory algorithm based on only the detection of hepatitis B surface antigen (HBsAg) leaves a gap for infected HBsAg negative donors to donate blood during the “window period” (WP) and late stages of infection. Objective: To estimate the frequency of the presence of HBV deoxyribonucleic acid (DNA) in HBsAg negative blood units screened using two different assays for HBsAg in a high endemic region. Methods: Frozen serum aliquot of 100 replacement blood donors who donated blood units that were HBsAg negative were retrieved and tested for HBV DNA. Sample positive for HBV DNA was sequenced by Sanger’s method, genotyped and the viral load was determined. Results: One sample (1%) was positive for HBV DNA. The HBV viral load of the sample was 768,000 IU/ml. The partial S-gene of the Hepatitis B virus isolated was genotype E using the NCBI viral genotyping tool. Conclusions: There is still a risk of HBV infected blood unit escaping detection when donor testing is limited to HBsAg screening. The use of NAT which can substantially reduce HBV infected blood donors from the donor pool should be considered. Keywords: Hepatitis B surface Antigen; Hepatitis B Virus; DNA; blood donors; blood safety.

Postscript

This chapter reveals some of the major changes in the European and UK regulatory framework following the UK leaving the EU (Brexit), public health consequences of the supply of infected blood products, and the Covid-19 pandemic. It covers issues that occurred after Brexit, the independent medicines and medical devices safety review, and the UK blood enquiry. It also mentions the Medicines and Healthcare products Regulatory Agency (MHRA) that became the UK’s standalone regulator of medicines and medical devices since 1 January 2021, acting independently in joint work with other international regulators. The chapter elaborates on the UK’s intention to develop a new regulatory framework for medical devices that reflect the Independent Medicines and Medical Devices Safety Review published in July 2020. It highlights the European Medicines Agency’s (EMA) cooperation with the World Health Organization (WHO) on developing potential Covid-19 treatments by facilitating large-scale clinical trials.

Transmission of HIV through blood and blood products in the Eastern Mediterranean Region

Over90% of recipients of HIV infected blood will seroconvert. In the Region 368 cases were due to transmission through blood or blood products. With establishment of HIV screening facilities, the proportion of AIDS cases due to blood transmission has decreased. AIDS due to blood transmission will continue to occur due to the time lag between the occurrence of HIV infection and appearance of AIDS. HIV seroprevalence among recipients of multiple blood transfusions decreased from 270 per 10 000 in 1987-89 to 7 per 10 000 in 1995. Effective methods are available for prevention of HIV transmission through blood, but antigen and PCR tests are expensive and not recommended for screening of blood donations in developing countries

Removing hepatitis C virus from polytetrafluoroethylene-coated orthodontic archwires and other dental instruments

Thefficacy of removing, rather than destroying, hepatitis C virus [HCV] from polytetrafluoroethylene [PTFE] -coated orthodontic archwires was tested. PTFE-coated archwires, pieces of PTFE and endodontic files [20 each] were immersed in HCV-infected blood for 24 hours. Half were washed under running water for 10 seconds while the remainder were thoroughly scrubbed with a toothbrush under running water for 10 seconds. Items were kept in separate dishes of distilled water for 24 hours. Reverse transcription polymerase chain reaction was used for viral replication. Viruses were detected by the gel method using a transilluminator. Only scrubbed PTFE pieces and coated archwires were negative for HCV. This suggests that PTFE coating of dental instruments inhibited HCV adhesion when thoroughly scrubbed

Lessons learnt from syphilis-infected blood donors: a timely reminder of missed opportunities

ObjectiveDue to the increased number of syphilis infections diagnosed in the UK and beyond, we reviewed our data on blood donors infected with syphilis in the UK and Ireland between 2016 and 2019.MethodsData were extracted from the surveillance database for all blood donors confirmed positive for syphilis in the UK and Ireland between 2016 and 2019, together with the total number of donations tested during that period. Data on positive cases included gender, age group, reported treatment, symptoms and confirmatory results. All cases were divided into recently acquired within 24 months and past syphilis infection. We also reviewed the information on symptoms characteristic of syphilis reported by blood donors with an untreated syphilis infection during the postdonation discussions.ResultsScreening of 8 246 600 blood donations for treponemal antibodies identified 316 blood donors with confirmed syphilis infection in the UK and Ireland between 2016 and 2019 (1.6 per 100 000 donations). 42% of them (133 of 316) were classed as a recent infection based on their donation testing results, previous donation date and clinical history provided, and they were hence considered potentially infectious. Most of these blood donors (202 of 316, 64%) had not been previously diagnosed or treated for syphilis, although 50 of them reported symptoms consistent with syphilis infection and 19 had been misdiagnosed despite seeking medical help.ConclusionsThis observational study shows that syphilis infection remains undiagnosed, especially among heterosexual men, and that infectious syphilis is often missed as a differential diagnosis even when donors have presented with genital or oral ulceration, rashes in the genital area and lymphadenopathy. Considering the recent resurgence of syphilis infections in the UK and beyond and our generally expanding sexual networks, it is important to consider syphilis in differential diagnosis even if specific risk factors have not been identified.