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Kaposi sarcoma (KS) is an AIDS-defining angio-proliferative malignancy, with the Kaposi sarcoma-associated herpes virus (KSHV) as its etiologic agent. Upon treatment with chemotherapy, a proportion of HIV-associated KS patients experience disease recurrence within a few months of completing treatment. We aimed at determining whether KSHV-specific adaptive immune responses were associated with KS recurrence upon complete remission. We conducted a prospective cohort study. The primary outcome was the recurrence of HIV-associated KS. An immunofluorescence assay was used to determine anti-KSHV antibodies, an enzyme-linked immunospot was conducted for T cell responses, PCR was carried out to determine KSHV status, and flow cytometry was used for CD4 counting and immunophenotyping. KSHV detection in PBMCs was high and not associated with KS recurrence-free survival (p = 0.29). Anti-KSHV antibody titers were high and not associated with recurrence-free survival (p = 0.63). KSHV-specific T cell responses dropped from baseline levels among individuals with recurrence, but the drop was not statistically significant. Individuals experiencing KS recurrence had a significantly higher proportion of T cell subsets expressing PD1, while those with sustained remission had a significant increase in CD4 T cell counts from baseline levels during the follow-up period (p = 0.02). Anti-KSHV antibodies are not a good correlate of protection from KS recurrence. T cells in individuals experiencing KS recurrence hadhigh PD1 expression, while an increase in CD4 counts was associated with sustained KS remission.

Abstract High-quality, representative serological surveys allow direct estimates of immunity profiles to inform vaccination strategies but can be costly and logistically challenging. Leveraging residual serum samples is one way to increase their feasibility. We subsampled 9854 residual sera from a 2016 national HIV survey in Zambia and tested these specimens for anti-measles and anti-rubella virus IgG antibodies using indirect enzyme immunoassays. We demonstrate innovative methods for sampling residual sera and analyzing seroprevalence data, as well as the value of seroprevalence estimates to understand and control measles and rubella. National measles and rubella seroprevalence for individuals younger than 50 years was 82.8% (95% CI 81.6, 83.9%) and 74.9% (95% CI 73.7, 76.0%), respectively. Despite a successful childhood vaccination program, measles immunity gaps persisted across age groups and districts, indicating the need for additional activities to complement routine immunization. Prior to vaccine introduction, we estimated a rubella burden of 96 congenital rubella syndrome cases per 100,000 live births. Residual samples from large-scale surveys can reduce the cost and challenges of conducting serosurveys, and multiple pathogens can be tested. Procedures to access quality specimens, ensure ethical approvals, and link sociodemographic data can improve the timeliness and value of results.

Abstract Background A proportion of COVID19 survivors may present with long‐COVID, which is persistent symptoms lasting four or more weeks post SARS‐CoV‐2 infection. These symptoms may be mild to severe, and may affect different organ‐systems of the body. Aims The main objective of this study was to determine the demographic, clinical and immunological factors associated with long COVID. Materials & Methods We conducted a nested case control study, with a total of 94 study participants initially included, and 64 participants matched for age and sex for biomarker analyses. Results 32/94 (34.1%) of all the participants had long COVID. Respiratory symptoms were the most common (59.5%) followed by the musculoskeletal symptoms (28.1%). HIV was an independent predictor of long COVID (adjusted odds ratio = 2.7; p = .037). In all the 64 matched cases and controls, IFN‐β was significantly higher among controls than cases. After stratifying by HIV, IL6 was significantly higher among cases than controls in the HIV‐ group (2.06 vs. 0.81 pg/mL; p = .02). On the other hand, IFN‐β was significantly higher among controls than cases in the HIV+ group (251 vs. 0 pg/mL; p = .01). Conclusion HIV infection is a risk factor for long COVID, and inflammatory markers associated with long COVID may be slightly different for HIV− and HIV+ individuals.

BackgroundIn Zambia, before rotavirus vaccine introduction, the virus accounted for about 10 million episodes of diarrhoea, 63 000 hospitalisations and 15 000 deaths in 2015, making diarrhoea the third leading cause of death after pneumonia and malaria. In Zambia, despite the introduction of the vaccine acute diarrhoea due to rotaviruses has continued to affect children aged five years and below. This study aimed to characterise the rotavirus genotypes which were responsible for diarrhoeal infections in vaccinated infants aged 2 to 12 months and to determine the relationship between rotavirus strains and the severity of diarrhoea in 2016.MethodsStool samples from infants aged 2 to 12 months who presented to the hospital with acute diarrhoea of three or more episodes in 24 hours were tested for group A rotavirus. All positive specimens that had enough sample were genotyped using reverse transcriptase Polymerase Chain Reaction (RT-PCR). A 20-point Vesikari clinical score between 1-5 was considered as mild, 6-10 as moderate and greater or equal to 11 as severe.ResultsA total of 424 stool specimens were tested of which 153 (36%, 95% CI 31.5% to 40.9%) were positive for VP6 rotavirus antigen. The age-specific rotavirus infections decreased significantly (p = 0.041) from 2-4 months, 32.0% (49/118) followed by a 38.8% (70/181) infection rate in the 5-8 months' category and subsequently dropped in the infants aged 9-12 months with a positivity rate of 27.2%. 38.5% of infants who received a single dose, 34.5% of those who received a complete dose and 45.2% (19/42) of the unvaccinated tested positive for rotavirus. The predominant rotavirus genotypes included G2P[6] 36%, G1P[8] 32%, mixed infections 19%, G2P[4] 6%, G1P[6] 4% and G9P[6] 3%.Discussion and conclusionResults suggest breakthrough infection of heterotypic strains (G2P[6] (36%), homotypic, G1P[8] (32%) and mixed infections (19%) raises concerns about the effects of the vaccination on the rotavirus diversity, considering the selective pressure that rotavirus vaccines could exert on viral populations. This data indicates that the rotavirus vaccine has generally reduced the severity of diarrhoea despite the detection of the virus strains.

ObjectivesThe main objectives of the study are to estimate HIV prevalence, active syphilis prevalence, and correlates of co-infection with HIV in Zambia, among recently sexually active individuals aged 15 to 59 years old.MethodsWe used data from the 2016 Zambia Population-based HIV Impact Assessment (ZAMPHIA), a national household survey that included biomarker testing for HIV and syphilis. Chembio DPP® Syphilis Screen and Confirm Assay was used to distinguish between active and older syphilis infections. This is the first time Chembio DPP® has been used in a national survey. Log-binominal modelling was utilized to understand the risk of acquiring HIV/active syphilis co-infection using select socio-demographic and sexual behavior variables. Multivariable analysis compared those with co-infection and those with no infection. All reported results account for the complex survey design and are weighted.ResultsA total of 19,114 individuals aged 15-59 years responded to the individual interview and had a valid syphilis and/or HIV test. The prevalence for those sexually active in the 12 months preceding ZAMPHIA 2016 was 3.5% and 13% for active syphilis and HIV, respectively. The prevalence of HIV/active syphilis co-infection was 1.5%. Factors associated with higher prevalence of co-infection versus no infection among females included, but were not limited to, those living in urban areas (adjusted prevalence ratio (aPR) = 3.0, 95% CI = 1.8, 4.8), those had sexual intercourse before age 15 years (aPR = 1.8, 95% CI = 1.1, 2.9), and those who had two or more sexual partners in the 12 months preceding the survey (aPR = 2.7, 95% CI = 1.6, 4.7).ConclusionThese findings show high prevalence for both mono-infection with HIV and syphilis, as well as co-infection with HIV/active syphilis in Zambia. There is a need for better screening and partner services, particularly among those engaging in high-risk sexual behaviors (e.g., engaging in transactional sex).

Background: Staphylococcus aureus is a frequent cause of hospital-acquired infections worldwide. The carriage of S. aureus among healthcare workers has been associated with transmission of the bacterium to susceptible patients. Objectives: The aim of this study was to determine the carriage rate, antimicrobial susceptibility profile and spa type of S. aureus among healthcare workers at a large tertiary referral hospital in Lusaka, Zambia. Methods: This was a prospectivecross-sectional study that involved the collection of nasal and hand swabs from 140 healthcare workers from May to July 2017 at the University Teaching Hospital in Lusaka. In this study, we recruited 103 nurses, 28 doctors and 9 laboratory scientists. Conventional microbiological methods were used to isolate and identify S. aureus. Antimicrobial susceptibility testing, including methicillin resistance was determined using the disc diffusion method, while molecular analysis of the isolates was achieved by spa typing. Results: The overall S. aureus carriage among the health care workers was 17.1% (24/140). Of these, 13.6% (19/140) and 8.6% (12/140) were nasal and hand carriers, respectively. Carriage rate was highest among doctors (17.9%, 5/28), followed by nurses (17.5%, 18/103) and laboratory scientists (11.1%, 1/9). About 25.8% (8/31) of the S. aureus isolates were methicillin-resistant and showed resistance to more than four antibiotics. About 25.8% (8/31) of the S. aureus isolates were positive for the spa gene. Of these, seven were typeable. Two spa types, t015 (42.8%, 3/7) and t069 (14.3%, 1/7) were detected, whereas the spa type for 42.8% (3/7) of the isolates were unknown. Conclusion: The carriage of S. aureus and prevalence of Methicillin-resistant S. aureus among healthcare workers examined was high. This calls for regular intervention measures such as screening and decolonizing of healthcare workers to reduce the carriage and spread of this pathogen in healthcare centres in Zambia. Keywords: Antimicrobial resistance, Carriage rate, Healthcare workers, Methicillin-resistant Staphylococcus aureus, Spa typing