China
Africa
Explore chapters and articles related to this topic
Infectious Disease
Published in John S. Axford, Chris A. O'Callaghan, Medicine for Finals and Beyond, 2023
Susanna J. Dunachie, Hanif Esmail, Ruth Corrigan, Maria Dudareva
Diagnosis is by detection of DNA in blood by RT-PCR. Histology of tissue biopsy may reveal a characteristic appearance with ‘owl's eye’ inclusion bodies. Seroconversion can support a diagnosis of infection.
Immunization
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Michael F. Para, Susan L. Koletar, Carter L. Diggs
Artificially induced immunity may not be complete, and even with generally functional vaccines, one cannot always assume that protection has developed after immunization. One way of evaluating the immune response following injection of vaccine is the measurement of circulating antibodies to the antigens in the vaccine. The process of development of antibodies is called seroconversion. In some instances, the presence of circulating antibodies correlates well with development of protection. This is the case with hepatitis B and rubella vaccines. Antibody levels, however, do not tell the whole story. If there is a strong immunologic memory response, protection may exist in the absence of detectable antibody. For example, following vaccination with agents such as live attenuated measles and rubella vaccines, there will be an initial IgM antibody response, followed by a rise in IgG antibody titers. Over time, the antibody titers will fall, and although they may fall to undetectable levels, when infection occurs there is a rapid response by the memory cells. In such situations there is a prompt increase in IgG antibodies specific for the virus and protection from disease. The mere presence of antibody, however, may not be sufficient to assure protection from disease, but rather a minimum level of antibody may be required. Such is the case if immunity to tetanus is to be induced by injection of tetanus toxoid.
Other viral infections
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Transmission of the virus is by respiratory droplets, and the incubation period is 4 to 14 days. Viremia develops 7 to 8 days after initial infection, lasting approximately 4 days (34). The rash associated with B19 appears following the viremic phase. The primary host is no longer infectious once the rash appears. Initial infection and seroconversion provide the host with lifelong immunity and reinfection is rare.
Benznidazole for the treatment of Chagas disease
Published in Expert Review of Anti-infective Therapy, 2021
Irene Losada Galván, Julio Alonso-Padilla, Nuria Cortés-Serra, Cristina Alonso-Vega, Joaquim Gascón, María Jesús Pinazo
Seroconversion is also a consequence of the acute phase of the infection. Levels of anti-parasitic immunoglobulins rise and remain steady for years (mainly IgG class). Although beneficial toward achieving a diagnosis of the chronic stage by serological methods, the long-standing seropositive state largely precludes an early assessment of treatment efficacy. This is because levels of anti-T. cruzi IgG stay above their detection threshold despite the intake of anti-parasitic treatments. The consequence is that the evaluation of treatment response cannot be made early upon its administration by means of currently available serological tools. These might only be useful decades after treatment, which is the time that takes for anti-T. cruzi IgG levels to lower and become negative again in the absence of re-infection events [55]. This time-span offers an absolutely impractical perspective both for the management of patients in the daily clinic as well as for the evaluation of new drugs in clinical trials [56]. In search of a solution, several biomarkers are under research at present, including parasite-derived and host-derived ones [56]. But, despite advancements in the past few years, still there are no biomarker-based tests available for the early assessment of treatment efficacy.
Rigid monoclonal antibodies improve detection of SARS-CoV-2 nucleocapsid protein
Published in mAbs, 2021
Curtis D. Hodge, Daniel. J. Rosenberg, Patricia Grob, Mateusz Wilamowski, Andrzej Joachimiak, Greg L. Hura, Michal Hammel
SARS-CoV-2 nucleocapsid proteins (NP) are critical for incorporating and packaging viral genomic RNA into mature virions. In infected cells, NPs are produced in large amounts from subgenomic mRNA and are present at the replication-transcription complexes (RTCs), the sites of RNA synthesis. The NP gene is relatively conserved, with a sequence identity of 91% and 50% to SARS-CoV and MERS-CoV, respectively, and is rather stable, as it acquires few mutations over time.1,2 Although the NP from SARS-CoV-2 is abundant and highly immunogenic,3–5 most SARS-CoV-2 detection assays use different spike protein regions as the antigen in immunoassays. This is mainly because antibodies against the spike protein are believed to be less cross-reactive6 and are expected to correlate better with neutralizing capacity.7 Testing for serum antibodies against NP from SARS-CoV-2 was suggested to increase diagnostic capacity.4,8,9 However, serological assays cannot achieve diagnosis early in the onset of an infection because seroconversion occurs after 7–10 days in patients.3,4,10
Reassessing the Ethics of Molecular HIV Surveillance in the Era of Cluster Detection and Response: Toward HIV Data Justice
Published in The American Journal of Bioethics, 2020
Stephen Molldrem, Anthony K J Smith
A bioethics of the oppressed ought to take a capacious view of oppression, treating sexual marginality and other forms of individual or group deviance seriously as sources of stigma, marginalization, and subaltern status. There are subcultures of people who eroticize seroconversion, both in fantasy and in fact (Dean 2009; Klein 2014; Orne 2017, 49–50, 145–149). Additionally, many people from groups who are more likely to become HIV-positive are understandably ambivalent about the possibility of their own seroconversion (Halperin 2007; Sheon and Crosby 2004). For some of these individuals—who possess stigmatized and misunderstood sexual subjectivities—confirmation that they became infected with HIV from a particular person can be a validating affirmation of identity and even of communal belonging (Dean 2009; Klein 2014). Some people living with HIV refuse, delay, or interrupt treatment on a variety of bases, and for periods that vary (Persson et al. 2016). Others cannot sustain viral suppression even when taking antiretroviral therapies (Kiweewa et al. 2019). In the era of treatment as prevention, these groups are being pushed further to the margins of respectability in HIV discourse (Cormier McSwiggin 2017; Lloyd 2018); they should be included in HIV data justice-oriented conversations.