| 1. |
- Alfvén, Tobias, et al.
(författare)
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Mpox hos barn – svenskt perspektiv : Mpox and children - a Swedish perspective
- 2023
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Ingår i: Läkartidningen. - 0023-7205. ; 120
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Mpox (monkeypox) is an infection caused by the monkeypox virus, which belongs to the same family as the smallpox virus. Sporadic infections in humans have been known since the 1970s. Since spring 2022 there has been a global epidemic. The large majority of the mpox cases in the ongoing epidemic have been reported in adult men, the number of infected children is small. The typical manifestation of mpox includes a rash that initially presents as maculopapular lesions and then develops into vesicles and eventually crusts. Transmission of the virus primarily occurs through close contact with infected individuals, particularly through contact with unhealed blisters or wounds, as well as through sexual contacts and exposure to body fluids. In cases of documented close contact with an infected individual, post-exposure prophylaxis is recommended and may also be administered to children whose guardians have contracted mpox.
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| 2. |
- Asghar, Muhammad, et al.
(författare)
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Cellular aging dynamics after acute malaria infection : A 12-month longitudinal study
- 2018
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Ingår i: Aging Cell. - : Wiley. - 1474-9718 .- 1474-9726. ; 17:1, s. 12702-12702
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Tidskriftsartikel (refereegranskat)abstract
- Accelerated cellular aging and reduced lifespan have recently been shown in birds chronically infected with malaria parasites. Whether malaria infection also affects cellular aging in humans has not been reported. Here, we assessed the effect of a single acute Plasmodium falciparum malaria infection on cellular aging dynamics in travelers prospectively followed over one year in Sweden. DNA and RNA were extracted from venous blood collected at the time of admission and repeatedly up to one year. Telomere length was measured using real-time quantitative PCR, while telomerase activity and CDKN2A expression were measured by reverse transcriptase (RT)-qPCR. Our results show that acute malaria infection affects cellular aging as reflected by elevated levels of CDKN2A expression, lower telomerase activity, and substantial telomere shortening during the first three months postinfection. After that CDKN2A expression declined, telomerase activity increased and telomere length was gradually restored over one year, reflecting that cellular aging was reversed. These findings demonstrate that malaria infection affects cellular aging and the underlying cellular mechanism by which pathogens can affect host cellular aging and longevity need to be elucidated. Our results urge the need to investigate whether repeated malaria infections have more pronounced and long-lasting effects on cellular aging and lifespan (similarly to what was observed in birds) in populations living in malaria endemic areas.
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| 3. |
- Groenheit, Ramona, et al.
(författare)
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High Prevalence of SARS-CoV-2 Omicron Infection Despite High Seroprevalence, Sweden, 2022
- 2023
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Ingår i: Emerging Infectious Diseases. - : CENTERS DISEASE CONTROL & PREVENTION. - 1080-6040 .- 1080-6059. ; 29:6
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Tidskriftsartikel (refereegranskat)abstract
- We performed 2 surveys during 2022 to estimate point prevalences of SARS-CoV-2 infection compared with overall viral seroprevalence in Sweden. Point prevalence was 1.4% in March and 1.5% in September. Estimated seroprevalence was >80%, including among unvaccinated children. Continued SARS-CoV-2 surveillance is necessary for detecting emerging, possibly more pathogenic variants.
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| 4. |
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| 5. |
- Homann, Manijeh Vafa, et al.
(författare)
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Detection of Malaria Parasites After Treatment in Travelers : A 12-months Longitudinal Study and Statistical Modelling Analysis
- 2017
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 25, s. 66-72
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Tidskriftsartikel (refereegranskat)abstract
- The rapid clearance of malaria parasite DNA from circulation has widely been accepted as a fact without being systemically investigated. We assessed the persistence of parasite DNA in travelers treated for Plasmodium falciparum malaria in a malaria-free area. Venous blood was collected at the time of admission and prospectively up to one year. DNA and RNA were extracted and analyzed using species-specific and gametocyte-specific real-time PCR as well as merozoite surface protein 2 (msp2)-PCR. In 31 successfully treated individuals, asexual parasites were seen by microscopy until two days after treatment, whereas parasite DNA was detected by msp2- and species-specific PCR up to days 31 and 42, respectively. Statistical modelling predicted 26% (+/- 0.05 SE) species-specific PCR positivity until day 40 and estimated 48 days for all samples to become PCR negative. Gametocytes were detected by microscopy and PCR latest two days after treatment. C-T values correlated well with microscopy-defined parasite densities before but not after treatment started. These results reveal that PCR positivity can persist several weeks after treatment without evidence of viable sexual or asexual parasites, indicating that PCR may overestimate parasite prevalence after treatment.
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| 6. |
- Ivarson, Josefine, et al.
(författare)
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Call the On-Call : a study of student learning on an interprofessional training ward
- 2021
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Ingår i: Journal of Interprofessional Care. - : Informa UK Limited. - 1356-1820 .- 1469-9567. ; 35:2, s. 275-283
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Tidskriftsartikel (refereegranskat)abstract
- Interprofessional training wards are designed to train students’ team and communication competences. Such wards are generally highly valued clinical placements by undergraduate students; however, evidence in the literature suggests that medical students experience a lack of profession-specific tasks on these wards. Moreover, students lack structured training in the complexities of everyday communication where different health professions rarely are present together in stable teams. This paper reviews one strategy to train students in interprofessional communication while letting students perform profession-specific tasks. A qualitative study with ethnographically-collected data was conducted among three interprofessional student teams over three two-week periods, mixing field observations (75 h), interviews (n = 16), and field notes (45 pages). The findings show that students gained insights into new aspects of their professional roles and an appreciation of clear and open interprofessional communication over the telephone. Learning was facilitated through being confronted with new situations and discussing these experiences with each other over time. Call the On-Call as a pedagogic activity provided not just medical students, but also nursing students with new types of profession-specific tasks on the interprofessional training ward.
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| 7. |
- Jahnmatz, Peter, et al.
(författare)
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Memory B-Cell Responses Against Merozoite Antigens After Acute Plasmodium falciparum Malaria, Assessed Over One Year Using a Novel Multiplexed FluoroSpot Assay
- 2021
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Memory B cells (MBCs) are believed to be important for the maintenance of immunity to malaria, and these cells need to be explored in the context of different parasite antigens and their breadth and kinetics after natural infections. However, frequencies of antigen-specific MBCs are low in peripheral blood, limiting the number of antigens that can be studied, especially when small blood volumes are available. Here, we developed a multiplexed reversed B-cell FluoroSpot assay capable of simultaneously detecting MBCs specific for the four Plasmodium falciparum blood-stage antigens, MSP-1(19), MSP-2, MSP-3 and AMA-1. We used the assay to study the kinetics of the MBC response after an acute episode of malaria and up to one year following treatment in travelers returning to Sweden from sub-Saharan Africa. We show that the FluoroSpot assay can detect MBCs to all four merozoite antigens in the same well, and that the breadth and kinetics varied between individuals. We further found that individuals experiencing a primary infection could mount and maintain parasite-specific MBCs to a similar extent as previously exposed adults, already after a single infection. We conclude that the multiplexed B-cell FluoroSpot is a powerful tool for assessing antigen-specific MBC responses to several antigens simultaneously, and that the kinetics of MBC responses against merozoite surface antigens differ over the course of one year. These findings contribute to the understanding of acquisition and maintenance of immune responses to malaria.
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| 8. |
- Jahnmatz, Peter, et al.
(författare)
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Multiplex analysis of antigen-specific memory B cells in humans using reversed B-cell FluoroSpot
- 2020
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Ingår i: JIM - Journal of Immunological Methods. - : Elsevier BV. - 0022-1759 .- 1872-7905. ; 478
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of B-cell specificities at the single cell level provides important information on how the B-cell compartment responds when challenged by infection or vaccination. We recently developed a reversed B-cell FluoroSpot assay and showed that it could be used to detect B cells specific for different antigens simultaneously in a mouse model. The aim of this study was to further develop the method to detect and quantify antigen-specific memory B cells (MBCs) in humans where circulating antigen-specific cells are less frequent. We show that MBCs specific for three antigens, tetanus toxoid, hepatitis B surface antigen and cytomegalovirus pp65, could be detected simultaneously in one well. In addition to enumerating antigen-specific MBCs, we also assessed the spot volume to estimate the intensity of the response in individual cells and found this to be a new and sensitive approach to study MBC responses after vaccination. This unique B-cell FluoroSpot approach provides a simple and sensitive multiplex analysis of MBCs and can be adapted to most antigens and host species.
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| 9. |
- Karin, Hansen, et al.
(författare)
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Monkeypox virus-associated meningoencephalitis diagnosed by detection of intrathecal antibody production
- 2024
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Ingår i: BMC Infectious Diseases. - 1471-2334. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: In the 2022 mpox-outbreak most patients presented with mild symptoms. Central nervous system (CNS) involvement has previously been described as a rare and severe complication of mpox; however, diagnostic findings in cerebrospinal fluid (CSF) analysis and neuroimaging studies have only been reported in one case previously. Case presentation: We report a previously healthy 37-year-old man with mpox complicated by encephalitis. He first presented with painful skin lesions and genital ulcers; polymerase chain reaction (PCR) from the lesions was positive for mpox. Twelve days later he was admitted with fever and confusion. Neuroimaging and CSF analysis indicated encephalitis. The CSF was PCR-negative for monkeypox virus but intrathecal antibody production was detected. He spontaneously improved over a few days course and recovered fully. Conclusions: This case of mpox-associated encephalitis shows that CNS involvement in mpox infection may have a relatively mild clinical course, and that detection of intrathecal antibody production can be used to establish the diagnosis if CSF monkeypox virus-PCR is negative.
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| 10. |
- Sondén, Klara
(författare)
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Immunity to malaria: importance of exposure and parasite polymorphism
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Malaria continues to carry an intolerable burden of disease and mortality, predominantly on children in Sub-Saharan Africa. An efficacious vaccine would be a powerful tool in the combat against malaria. Further understanding of the mechanisms of naturally acquired immunity to the polymorphic Plasmodium falciparum parasite would aid vaccine development. The studies presented in this thesis contribute to the understanding of how immune responses are acquired in relation to exposure to the polymorphic P. falciparum parasite. More specifically, they investigated how the genetic diversity of the P. falciparum parasites encountered during childhood affects the risk of malaria (uncomplicated and severe), as well as whether maintenance of immune memory against P. falciparum antigens is maintained without repeated re-exposure. The thesis also included a description of a novel technique for dispersion of frozen blood clots for optimized DNA extraction and polymerase chain reaction (PCR). Immunity against severe malaria has been proposed to be acquired after single infections. A matched case-control study was nested within a birth cohort on the Kenyan Coast where three-monthly blood samples up to two years, with the aim to study how exposure patterns early in life affects the risk of developing severe malaria. P. falciparum infections detected at least once from birth conferred an increased risk of severe malaria and especially if infections with two or more parasite clones were ever detected. To optimize DNA extraction for the study above, a novel method was developed for dispersion of frozen residual clots saved from blood collected without anticoagulant for serum preparation. Compared to two commercial methods, high-speed shaking was most succesful in clot dispersion before DNA extraction and generated the highest sensitivity of PCR detection. Whether the genetic diversity of asymptomatic P. falciparum infections carried through the dry season affects the risk of malaria in the ensuing transmission season was investigated in a setting with intense but strictly seasonal malaria transmission in Mali. Individuals with multiclonal infections before the malaria season had a delayed time to their first febrile malaria episode and a lower incidence of malaria compared to individuals who were smear negative or only carried one parasite clone. The longevity of immune responses to malaria after a single exposure was assessed in travelers treated for malaria in Stockholm, Sweden, 1-16 years previously. P. falciparum-specific memory B-cells were maintained in a majority of study participants for up to 16 years without re-exposure, whereas circulating cognate antibodies were not detected. In conclusion, a single encounter with the parasite can induce immunological memory to P. falciparum antigens that lasts for many years. Severe malaria can occur in young children despite previous exposure, a finding that argues against the idea that severe malaria develops only after the first encounters with the parasite. Persistent asymptomatic infections, especially with genetically diverse infections, contribute to maintenance of immune responses that protect from malaria. This thesis presents different concepts and mechanisms of naturally acquired immunity to malaria that might be valuable in the development of malaria vaccines and other control strategies.
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