Reinfection or Reactivation of Coronavirus-19 in Patients with Hematologic Malignancies: Case Report Series

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been relentless. We are into the 10th month of the pandemic, and we are still getting surprised every day. Although neutralizing antibodies are generated in response to coronavirus disease-19 (COVID-19), these antibodies do not appear to confer lifelong immunity, as lately there have been reports from various parts of the world of reinfection with the virus, starting from Hong Kong, Belgium, and the USA. The Indian Council of Medical Research (ICMR) has been on-record claiming three cases of reinfection in India. Herein, we report three patients of hematologic malignancy who most probably had reinfection with SARS-CoV-2, after complete documented recovery from first infection. All three patients were immunocompromised owing to their primary hematologic malignancy coupled with ongoing therapy, and the second infection was documented to be severe in all the three cases from the first episode.

Long-term follow-up of patients with infective endocarditis in a tertiary referral center

BACKGROUND

Infective endocarditis (IE) remains a severe disease with high mortality. Most studies report on short-term outcome while real world long-term outcome data are scarce. This study reports reinfection rates and mortality data during long-term follow-up.

METHODS

A total of 270 patients meeting the modified Duke criteria for definite IE admitted to a tertiary care center between July 2000 and June 2007 were analyzed retrospectively. Early reinfection was defined as a new IE episode within 6 months; late reinfection as a new IE episode beyond 6 months follow-up.

RESULTS

Median follow-up was 8.5 years. Early reinfection occurred in 10 patients (3.7%), late reinfection in 18 patients (6.7%). Staphylococci (39.7%) were the most frequent causative microorganisms, followed by Streptococci (30.0%) and Enterococci (17.8%). Independent predictors of any reinfection were heart failure (HR 3.02, 95% CI 1.42-6.41), peripheral embolization (HR 4.00, 95% CI 1.58-10.17) and implanted pacemakers (HR 3.43, 95% CI 1.25-9.36). Survival rates were 71.1%, 55.2% and 43.3% at respectively 1-, 5- and 10-years follow-up. Independent predictors for mortality were age (HR 1.03, 95% CI 1.01-1.04), diabetes mellitus (HR 2.24, 95% CI 1.46-3.45), hemodialysis (HR 2.70, 95% CI 1.37-5.29), heart failure (HR 1.64, 95% CI 1.19-2.26), stroke (HR 1.73, 95% CI 1.18-2.52), antimicrobial treatment despite surgical indication (HR 5.53, 95% CI 3.59-8.49) and non-Streptococci causative microorganisms (HR 1.84, 95% CI 1.28-2.64).

CONCLUSIONS

Contemporary mortality rates of infective endocarditis remain high, irrespective of reinfection. Heart failure, peripheral embolization and presence of a pacemaker were predictors of reinfection.

Dynamics of viral load and anti-SARS-CoV-2 antibodies in patients with positive RT-PCR results after recovery from COVID-19

Recently, the number of patients with coronavirus disease 2019 (COVID-19) who have tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), via the reverse transcription polymerase chain reaction (RT-PCR) test, after recovery has increased; this has caused a dilemma regarding the medical measures and policies. We evaluated the dynamics of viral load and anti-SARS-CoV-2 antibodies in four patients with positive RT-PCR results after recovery. In all patients, the highest levels of immunoglobulin G (IgG) and IgM antibodies were reached after about a month of the onset of the initial symptoms. Then, the IgG titers plateaued, and the IgM titers decreased, regardless of RT-PCR results. The IgG and IgM levels did not increase after the post-negative positive RT-PCR results in any of the patients. Our results reinforced that the post-negative positive RT-PCR results may be due to the detection of RNA particles rather than reinfection in individuals who have recovered from COVID-19.

COVID-19 Reinfection in a Patient with Hodgkin Lymphoma: a Case Report

COVID-19 pneumonia has invaded the world and continues to expand. The current evidence of the immune system reaction to this viral pneumonia shows that the post-infectious immunity against the virus may be temporary, and the virus may reinfect the patients after healing from the previous one. Here is presented a 55-year-old female patient, as a known case of Hodgkin lymphoma, diagnosed with COVID-19 reinfection during 40 days. Such evidence may be helpful in further understanding the immunology of the disease.

Migration rate estimation in an epidemic network

Most of the recent epidemic outbreaks in the world have as a trigger, a strong migratory component as has been evident in the recent Covid-19 pandemic. In this work we address the problem of migration of human populations and its effect on pathogen reinfections in the case of Dengue, using a Markov-chain susceptible-infected-susceptible (SIS) metapopulation model over a network. Our model postulates a general contact rate that represents a local measure of several factors: the population size of infected hosts that arrive at a given location as a function of total population size, the current incidence at neighboring locations, and the connectivity of the network where the disease spreads. This parameter can be interpreted as an indicator of outbreak risk at a given location. This parameter is tied to the fraction of individuals that move across boundaries (migration). To illustrate our model capabilities, we estimate from epidemic Dengue data in Mexico the dynamics of migration at a regional scale incorporating climate variability represented by an index based on precipitation data.

Risk factors associated with prolonged viral clearance in patients with a refractory course of COVID-19: a retrospective study

BACKGROUND

This study aimed to characterize a cohort of patients with a refractory course of COVID-19, and to investigate factors associated with the duration of viral clearance (DoVC).

MATERIALS & METHODS

A total of 65 patients with refractory COVID-19 were retrospectively enrolled from Huoshenshan Hospital. Univariate analysis and multivariate analysis were performed to examine the potential association between clinicopathologic characteristics and the DoVC.

RESULTS

The median DoVC in the overall study cohort was 48 days (ranged from 21 to 104 days). Multivariate analysis indicated that fever at illness onset (Hazard ratio (HR) = 4.897, 95% CI [1.809-13.260], p = 0.002), serum level of aspartate aminotransferase (AST) > 21.8 IU/L (HR = 3.010, 95% CI [1.195-7.578], p = 0.019), and titer of SARS-CoV-2 IgG > 142.09 AU/ml (HR = 3.061, 95% CI [1.263-7.415], p = 0.013) were the three independent risk factors associated with delayed viral clearance.

CONCLUSION

The current study suggested that clinical characteristics such as fever at illness onset, a high serum level of AST or SARS-CoV-2 IgG were associated with delayed viral clearance. Patients with these characteristics might need a more individualized treatment strategy to accelerate their recovery from the refractory COVID-19.

Reinfection risk of novel coronavirus (COVID-19): A systematic ‎review of current evidence

BACKGROUND

There is recently a concern regarding the reinfection and reactivation of previously reCoVered coronavirus disease 2019 (CoVID-19) patients.

AIM

To summarize the recent findings and reports of CoVID-19 reinfection in patients previously reCoVered from the disease.

METHODS

This study was a systematic review of current evidence conducted in August 2020. The authors studied the probable reinfection risk of novel coronavirus (CoVID-19). We performed a systematic search using the keywords in online databases. The investigation adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to ensure the reliability and validity of this study and results.

RESULTS

We reviewed 31 studies. Eight studies described reCoVered patients with reinfection. Only one study reported reinfected patients who died. In 26 studies, there was no information about the status of the patients. Several studies indicated that reinfection is not probable and that post-infection immunity is at least temporary and short.

CONCLUSION

Based on our review, we concluded that a positive polymerase chain reaction retest could be due to several reasons and should not always be considered as reinfection or reactivation of the disease. Most relevant studies in positive retest patients have shown relative and probably temporary immunity after the reCoVery of the disease.

Recurrent SARS-CoV-2 infection resulting in acute respiratory distress syndrome and development of pulmonary hypertension: A case report

The COVID-19 pandemic has affected millions of individuals worldwide. In the United States, the rapid transmission of cases has created challenges for healthcare systems across the country. We report a case of a patient who fully recovered from COVID-19 with intermittent negative RT-PCR testing and a symptom free interval who went on to develop a second infection. The patient's second infection resulted in a more severe clinical course. The patient developed Acute Respiratory Distress Syndrome resulting in intubation twice and an extensive stay in the intensive care unit. Six weeks post-discharge, the patient was evaluated for continued dyspnea, hypoxia, and continued oxygen dependence. The patient subsequently underwent right heart catherization for further evaluation and was found to have newly developed pulmonary hypertension. Given the possibility of second wave infections this fall and winter, this case highlights the concern that re-infections with COVID-19 could cause substantially worse clinical outcomes and long-term complications. In terms of ongoing vaccine development, the short lived immune response in this case calls into question the ability of a future vaccine to provide long term lasting immunity against COVID-19.

[Immune characteristics of Plasmodium reinfections in mice following chloroquine cure of primary Plasmodium infections]

OBJECTIVE

To investigate the disease progression and immunoprotective characteristics in mice re-infected with homogeneous/heterogeneous Plasmodium strains following cure of Plasmodium infections with chloroquine at the peak of parasitemia.

METHODS

C57BL/6 mice were infected with the non-lethal P. yoelii 17XNL strain, and half of mice were given treatment with chloroquine at the peak of parasitemia (9 days post-infection), while the other mice were self-cured naturally. Then, all cured mice were re-infected with the equivalent lethal P. yoelii 17XL or P. berghei ANKA strain 90 days following primary Plasmodium infections. The parasitemia levels during primary infections and reinfections were measured by microscopic examinations of Giemsa-stained thin blood films, and the levels of the IgG antibody in sera and the percentages of memory T cell subsets in spleen cells were detected in mice using ELISA and flow cytometry before and after parasite reinfections, respectively.

RESULTS

Following primary infections with the P. yoelii 17XNL strain, the serum IgG antibody levels were (5.047 ± 0.924) pg/mL in the selfcured mice and (4.429 ± 0.624) pg/mL in the chloroquine-treated mice, respectively (t = 0.437, P > 0.05), which were both significantly higher than that in the uninfected mice (1.624 pg/mL ± 0.280 pg/mL) (F = 22.522, P < 0.01). There was no significant difference in the serum IgG antibody level among self-cured and chloroquine-treated mice re-infected with the P. yoelii 17XL strain or the P. berghei ANKA strain (F = 0.542, P > 0.05); however, the serum IgG antibody levels were all significantly higher in selfcured and chloroquine-treated mice re-infected with the P. yoelii 17XLstrain[(15.487±1.173)pg/mLand(15.965±1.150)pg/mL] or the P. berghei ANKA strain [(14.644 ± 1.523) pg/mL and (15.185 ± 1.333) pg/mL] relative to primary infections (F = 67.383, P < 0.01). There was no significant difference in the proportion of CD4⁺ [(34.208 ± 2.106), (32.820 ± 1.930), (34.023 ± 2.289), (35.608 ± 1.779) pg/mL] or CD8⁺ T memory cells [(17.935 ± 2.092), (18.918 ± 2.823), (17.103 ± 1.627), (17.873 ± 1.425) pg/mL] in self-cured and chloroquine-treated mice with primary infections with the P. yoelii 17XNL strain followed by re-infections with the P. yoelii 17XL strain or the P. berghei ANKA strain (F = 0.944 and 0.390, both P > 0.05); however, the proportions of the CD4⁺ or CD8⁺ T memory cells were significantly greater in self-cured and chloroquine-treated mice with primary infections with the P. yoelii 17XNL strain followed by re-infections with the P. yoelii 17XL strain or the P. berghei ANKA strain than in mice with primary infections (F = 50.532 and 21.751, both P < 0.01).

CONCLUSIONS

The cure of murine Plasmodium infections with chloroquine does not affect the production of effective immune protections in mice during parasite re-infections. Following a primary infection, mice show a protection against re-infections with either homogeneous or heterogeneous Plasmodium strains, and a higher-level resistance to re-infections with homogeneous parasite strains is found than with heterogeneous strains.

COVID-19 in a multiple sclerosis (MS) patient treated with alemtuzumab: Insight to the immune response after COVID

BACKGROUND

The severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a novel disease that has spread abruptly over the world, allowing the development of countermeasures an urgent global priority. It has been speculated that elder people and patient with comorbidities may be at risk of developing complication. On the other hand, it has been seen that immunosuppressed patients could develop a mild presentation of the disease. Based on this hypothesis, several immunosuppressant agents are currently being tested as potential treatment for coronavirus 2019 (COVID-19).

METHODS

report a patient treated with alemtuzumab (Humanized monoclonal antibody against the lymphocyte and monocyte surface antigen CD52, which depletes B and T cells) (Thompson et al., 2018) for recurrent remittent multiple sclerosis (RRMS) who developed mild COVID-19.

RESULTS

Despite complete B and T cell depletion, patient symptoms abated few days with no need for hospitalization due to COVID-19 and no clinical evidence of disease activation regarding her MS.

DISCUSSION

This report shows that MS patients with mild depletion of B and T cells can mount an antiviral response against COVID-19 and produce IgG.

Risk factors for recurrent tuberculosis after successful treatment in a high burden setting: a cohort study

BACKGROUND

People successfully completing treatment for tuberculosis remain at elevated risk for recurrent disease, either from relapse or reinfection. Identifying risk factors for recurrent tuberculosis may help target post-tuberculosis screening and care.

METHODS

We enrolled 500 patients with smear-positive pulmonary tuberculosis in South Africa and collected baseline data on demographics, clinical presentation and sputum mycobacterial cultures for 24-loci mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing. We used routinely-collected administrative data to identify recurrent episodes of tuberculosis occurring over a median of six years after successful treatment completion.

RESULTS

Of 500 patients initially enrolled, 333 (79%) successfully completed treatment for tuberculosis. During the follow-up period 35 patients with successful treatment (11%) experienced a bacteriologically confirmed tuberculosis recurrence. In our Cox proportional hazards model, a 3+ AFB sputum smear grade was significantly associated with recurrent tuberculosis with a hazard ratio of 3.33 (95% CI 1.44-7.7). The presence of polyclonal M. tuberculosis infection at baseline had a hazard ratio for recurrence of 1.96 (95% CI 0.86-4.48).

CONCLUSION

Our results indicate that AFB smear grade is independently associated with tuberculosis recurrence after successful treatment for an initial episode while the association between polyclonal M. tuberculosis infection and increased risk of recurrence appears possible.

The first case of documented Covid-19 reinfection in Israel

We describe the first documented case of Covid-19 reinfection in Israel, out of only a handful such case worldwide, in a 20 year old otherwise healthy young woman. In the first occasion she was mildly symptomatic, whereas the second episode was apparently asymptomatic, except for tachycardia of 90/min, compared to 60/min in the first episode. The fact that out of 25 million infected persons worldwide only a handful of re-infected cases have been identified suggests that this is a rare phenomenon. Alternatively, it will be critical to rule out that new mutations are not introduced, which are not covered by existing immunity.

Simulation of coronavirus disease 2019 (COVID-19) scenarios with possibility of reinfection

Epidemiological models of COVID-19 transmission assume that recovered individuals have a fully protected immunity. To date, there is no definite answer about whether people who recover from COVID-19 can be reinfected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In the absence of a clear answer about the risk of reinfection, it is instructive to consider the possible scenarios. To study the epidemiological dynamics with the possibility of reinfection, I use a Susceptible-Exposed-Infectious-Resistant-Susceptible model with the time-varying transmission rate. I consider three different ways of modeling reinfection. The crucial feature of this study is that I explore both the difference between the reinfection and no-reinfection scenarios and how the mitigation measures affect this difference. The principal results are the following. First, the dynamics of the reinfection and no-reinfection scenarios are indistinguishable before the infection peak. Second, the mitigation measures delay not only the infection peak, but also the moment when the difference between the reinfection and no-reinfection scenarios becomes prominent. These results are robust to various modeling assumptions.

Toxoplasma gondii: Cytokine responses in mice reinfected with atypical strains

This study aimed to elucidate the cellular immune response against Toxoplasma gondii in chronically infected mice reinfected with different strains of the parasite to elucidate the immunological basis for chronicity or virulence and to uncover the involvement of genes that encode virulence proteins and modulate the immune response. BALB/c mice were infected by oral gavage with non-virulent D8 strain and challenged 45 days post-infection with virulent EGS or CH3 strains. Cytokine measurement was performed 2 days post-challenge in cell extracts of the small intestine and 2, 7, and 14 days post-challenge in serum. Virulence gene allele type of these strains was analyzed. Challenged mice survived by avoiding exacerbated inflammation and inhibiting the overproduction of cytokines. Local and systemic cytokine response in challenged mice was similar to chronic controls and quite distinct in mice acutely infected with the EGS or CH3 strains. Allelic combinations of the virulence genes ROP5/ROP18 was predictive of virulence in mice when tested in these T. gondii strains. Other allelic combinations of rhoptries and dense granules genes showed discrepancies.

Reinfection or inaccuracy of antibody testing

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Possible reinfection with SARS-CoV-2 in an ESRD patient with prior positive IgG antibody test against SARS-CoV-2.

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Potential lack of antibody protection after asymptomatic infection in ESRD patients.

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The prospect of antibody dependent enhancement.

•

The need for careful interpretation of antibody test in ESRD patients until further understanding of reinfection risk and antibody response.

A patient with end-stage renal disease on hemodialysis with a previous positive SARS-CoV-2 IgG antibody was diagnosed with severe COVID-19. Issues regarding reinfection, the potential lack of antibody protection after asymptomatic infection, the possibility of antibody dependent enhancement and careful interpretation of antibody test results are discussed.

Impact of fascioliasis reinfection on Fasciola hepatica egg shedding: relationship with the immune-regulatory response

Fascioliasis is a disease caused by liver flukes. In human fascioliasis hyperendemic areas, reinfection and chronicity are the norm. Control strategies in humans require the use of egg count techniques to calculate the appropriate treatment dose for colic risk prevention. The present study investigates how fascioliasis reinfection affects liver fluke egg shedding and its relationship with the immune-regulatory response. The experimental design reproduced the usual reinfection/chronicity conditions in human fascioliasis endemic areas and included Fasciola hepatica primo-infected Wistar rats (PI) and rats reinfected at 4 weeks (R4), 8 weeks (R8), 12 weeks (R12), and negative control rats. In a longitudinal study (0-20 weeks post-infection, p.i.), serical IgG1 levels and eggs per gram of faeces (epg) were analyzed. In a cross-sectional study, the expression of the genes associated with Th1 (Ifng, Il12a, Il12b, Nos2), Th2 (Il4, Arg1), Treg (Foxp3, Il10, Tgfb, Ebi3), and Th17 (Il17) in the spleen and thymus was analyzed. In R8 and R12, transiently higher averages of epg and epg/worm in reinfected groups vs PI group were detected at least in the weeks following reinfection. The kinetics of IgG1 levels shows that reinfected groups followed a pattern similar to the one in the PI group, but transiently higher averages of IgG1 levels in reinfected groups vs the PI group were detected in the weeks following reinfection. Epg correlated with IgG1 levels and also with systemic Il10 and thymic Ifng, and Il10 expression levels. These results suggest that epg depends on the Th1 and Treg phenotype and that the determination of the fluke burden by epg is likely to be an overestimation in cases of recent reinfection in low burden situations. A strategy to facilitate the implementation of epg count techniques and the subsequent decision on the appropriate treatment dose for each patient to prevent colic risk is required.

Case report on a swift shift in uropathogens from Shigella flexneri to Escherichia coli: a thin line between bacterial persistence and reinfection

Background

Urinary tract infections (UTI) are mostly caused by bacteria. Urine cultures are usually a definitive measure to select the appropriate antibiotics for the elimination of a uropathogen and subsequent recovery from the infection. However, the preferred antibiotics as determined by urine culture and sensitivity may still not eliminate the infection and would require further examination to ascertain the cause of treatment failure which could be unresolved bacteriuria, bacterial persistence, immediate reinfection with a different uropathogen or misdiagnosis.

Case presentation

A 2-years 7 months-old female was admitted in the Regional hospital of Buea following persistent fever. An auto medication with amoxicillin was reported. Urinalysis was done on the first day and the sediment of the cloudy urine revealed many bacteria and few pus cells. Ceftriaxone was prescribed as empirical treatment and a request for urine and blood culture was made. Three days after admission, the temperature and CRP were 39.0 °C and 96 mg/l, respectively. The urine culture results (> 10⁵ CFU/ml of Shigella flexneri sensitive to ofloxacin) were presented to the doctor on the 4th day of admission. Patient was put on ofloxacin. Three days after, the temperature (38.5 °C) and CRP (24 mg/l) were still elevated. The blood culture result came out negative. A second urine culture was requested which came back positive (> 10⁵ CFU/ml of Escherichia coli resistant to ofloxacin and sensitive to meropenem and amikacin). Ofloxacin was discontinued and the patient put on meropenem and amikacin. The third urine culture recorded no significant growth after 48 h of incubation. The patient was discharged looking healthy once more with a normal body temperature.

Conclusion

Antibiotics tailored towards the elimination of a particular bacterial species may as well provide a favorable environment for other bacterial species that are resistant to it in the course of treating a UTI episode. This apparent treatment failure may first of all require a second urine culture for confirmation rather than considering the possibilities of a misdiagnosis.

Is novel coronavirus 2019 reinfection possible? Interpreting dynamic SARS-CoV-2 test results

Since December 2019, COVID-19, the clinical syndrome associated with SARS-CoV-2 infection, has infected more than 6.2 million people and brought the function of the global community to a halt. As the number of patients recovered from COVID-19 rises and the world transitions toward reopening, the question of acquired immunity versus the possibility of reinfection are critical to anticipating future viral spread. Here, we present a case of a patient previously recovered from COVID-19 who re-presents with new respiratory, radiographical, laboratory, and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) findings concerning for possible re-infection. We review this case in the context of the evolving discussion and theories surrounding dynamic RT-PCR results, prolonged viral shedding, and the possibility of developed immunity. Understanding how to interpret dynamic and late-positive SARS-CoV-2 RT-PCR results after primary infection will be critical for understanding disease prevalence and spread among communities worldwide.

Opportunistic treatment of hepatitis C virus infection (OPPORTUNI-C): study protocol for a pragmatic stepped wedge cluster randomized trial of immediate versus outpatient treatment initiation among hospitalized people who inject drugs

Background

Scaled-up direct-acting antiviral (DAA) treatment of hepatitis C virus (HCV) infection among people who inject drugs (PWID) is crucial to reach the World Health Organization HCV elimination targets within 2030. One of the critical obstacles to HCV care in this population is the lack of treatment models within specialist healthcare adapted to marginalized individuals.

Methods

OPPORTUNI-C is a pragmatic stepped wedge cluster randomized trial comparing the efficacy of immediate initiation of HCV treatment with the current standard of care among PWID admitted for inpatient care. Screening for HCV RNA will be performed as soon as possible after admission. The intervention includes immediate non-invasive liver disease assessment, counseling, and initiation of pan-genotypic DAA treatment with individualized follow-up. Standard of care is a referral to outpatient care at discharge. To mimic usual clinical practice as closely as possible, we will use a pragmatic clinical trial approach utilizing clinical infrastructure, broad eligibility criteria, flexible intervention delivery, clinically relevant outcomes, and collection of data readily available from the electronic patient files. The stepped wedge design involves a sequential rollout of the intervention over 16 months, in which seven participating clusters will be randomized from standard of care to intervention in a stepwise manner. Randomization will be stratified according to cluster size to keep high prevalence clusters separated. The trial will include approximately 220 HCV RNA positive individuals recruited from departments of internal medicine, addiction medicine, and psychiatry at Akershus University Hospital, Oslo University Hospital, and Lovisenberg Diaconal Hospital, Oslo, Norway. Individuals not able or willing to give informed consent and those with ongoing HCV assessment or treatment will be excluded. The primary outcome is treatment completion, defined as dispensing of the final prescribed DAA package from the pharmacy within 6 months after inclusion. Secondary outcomes include treatment uptake, virologic response, reinfection incidence, and resistance-associated substitutions.

Discussion

Representing a novel model of care suited to reach and engage marginalized PWID in HCV care, this study will inform HCV elimination efforts locally and internationally. If the model proves efficacious and feasible, it should be considered for broader implementation, replacing the current standard of care.

Trial registration

ClinicalTrials.gov, NCT04220645. Registered on 7 January 2020.

COVID-19 Reinfection: Myth or Truth?

The novel coronavirus disease (COVID-19) has posed a large problem to this world and has exposed the skeleton of healthcare system all over. There have been reports of patients getting reinfected with COVID-19 as they tested positive for the virus again after discharge. We try to address the issue of this reinfection and want to clarify whether this entity actually exists or is it just a myth.

Repetitive cellulitis caused by Streptococcus agalactiae isolates with different genotypic and phenotypic features in a patient having upper extremity with lymphedema after mastectomy and axillary lymph node dissection

•This is 3 episodes of repetitive cellulitis due to S. agalactiae (GBS) isolates.

•There was the possibility of GBS colonization in the genitourinary tracts.

•Blood-origin 3 isolates showed different genotypic and phenotypic features.

•These findings suggest the heterogeneity in strains endogenous to this patient.

•Our report supports the reinfection with endogenous GBS rather than recurrence.

Previously reported cases of recurrent cellulitis/erysipelas affecting chronically lymphedematous skin regions have been demonstrated to be due to Streptococcus agalactiae isolates with closely related genetic background which may be suggestive of relapse rather than reinfection. Herein, we report the occurrence of three episodes of repetitive cellulitis caused by S. agalactiae strains with different genotypic and phenotypic characteristics, including different antimicrobial susceptibility patterns (tetracycline, macrolide/lincosamide, and fluoroquinolone classes), in the left upper extremity of a patient with lymphedema, following left mastectomy and axillary lymph node dissection. The genotypic and phenotypic characteristics of the three isolates were confirmed based on the random amplified polymorphic DNA patterns, DNA profiles of virulence factors (bca–rib–bac–lmb–cylE), data on biofilm formation and cell invasion, antimicrobial susceptibility testing results, antimicrobial resistance (AMR) genotypes, and amino acid mutations associated with AMR. These results revealed that reinfection with S. agalactiae, rather than recurrence, occurred during the three episodes. In conclusion, microbiologic studies such as blood cultures or tissue cultures are certainly helpful in the management of recurrent infections or invasive infections such as bacteremia in order to better target antimicrobial therapy, regardless of the data previously presented.

Hepatitis C reinfection after successful antiviral treatment among people who inject drugs: A meta-analysis

BACKGROUND & AIMS

HCV reinfection following successful treatment can compromise treatment outcomes. This systematic review assessed the rate of HCV reinfection following treatment among people with recent drug use and those receiving opioid agonist therapy (OAT).

METHODS

We searched bibliographic databases and conference abstracts for studies assessing post-treatment HCV reinfection rates among people with recent drug use (injecting or non-injecting) or those receiving OAT. Meta-analysis was used to cumulate reinfection rates and meta-regression was used to explore heterogeneity across studies.

RESULTS

Thirty-six studies were included (6,311 person-years of follow-up). The overall rate of HCV reinfection was 5.9/100 person-years (95% CI 4.1-8.5) among people with recent drug use (injecting or non-injecting), 6.2/100 person-years (95% CI 4.3-9.0) among people recently injecting drugs, and 3.8/100 person-years (95% CI 2.5-5.8) among those receiving OAT. Reinfection rates were comparable following interferon-based (5.4/100 person-years; 95% CI 3.1-9.5) and direct-acting antiviral (3.9/100 person-years; 95% CI 2.5-5.9) therapy. In stratified analysis, reinfection rates were 1.4/100 person-years (95% CI 0.8-2.6) among people receiving OAT with no recent drug use, 5.9/100 person-years (95% CI 4.0-8.6) among people receiving OAT with recent drug use, and 6.6/100 person-years (95% CI 3.4-12.7) among people with recent drug use not receiving OAT. In meta-regression analysis, longer follow-up was associated with lower reinfection rate (adjusted rate ratio [aRR] per year increase in mean/median follow-up 0.77; 95% CI 0.69-0.86). Compared with people receiving OAT with no recent drug use, those with recent drug use receiving OAT (aRR 3.50; 95% CI 1.62-7.53), and those with recent drug use not receiving OAT (aRR 3.96; 95% CI 1.82-8.59) had higher reinfection rates.

CONCLUSION

HCV reinfection risk following treatment was higher among people with recent drug use and lower among those receiving OAT. The lower rates of reinfection observed in studies with longer follow-up suggested higher reinfection risk early post-treatment.

LAY SUMMARY

Our findings demonstrate that although reinfection by hepatitis C virus occurs following successful treatment in people with recent drug use, the rate of hepatitis C reinfection is lower than the rates of primary infection reported in the literature for this population - reinfection should not be used as a reason to withhold therapy from people with ongoing injecting drug use. The rate of hepatitis C reinfection was lowest among people receiving opioid agonist therapy with no recent drug use. These data illustrate that harm reduction services are required to reduce the reinfection risk, while regular post-treatment hepatitis C assessment is required for early detection and retreatment.

Outcome of Sclerokeratoplasty in Devastating Sclerocorneal Infections

Purpose:

To assess the achievement of anatomical integrity after primary tectonic sclerokeratoplasty procedure and outcome after subsequent secondary procedures to manage devastating corneoscleral infection threatening the structural integrity of the eyeball.

Methods:

This prospective interventional study comprised 60 patients with severe devastating corneoscleral pathology of infective origin with varying degrees of scleral involvement who underwent tectonic sclerokeratoplasty. They were grouped into three groups according to the involvement of scleral quadrants, i.e., Group A with only one quadrant, Group B with two quadrants, and Group C with more than two quadrants. The demographics, clinical features, microbiological status, postoperative complications, need for secondary procedures, and tectonic outcome in terms of anatomical success were analyzed in all three groups during follow-up between 2 and 5 years.

Results:

The donor graft size in Groups A, B, and C was 9.5–10.5, 11–12, and 12.5–14 mm, respectively. Globe integrity after primary procedure was noted in all patients of Group A, 76% of Group B, and 38% of Group C. Reinfection was observed in 19 cases of Groups B and C, from which 5 Group C patients were eviscerated and 14 underwent regrafting. Postoperative complications (suture related, rejection, graft failure, and secondary glaucoma) were encountered more frequently in Group C patients. Secondary procedures (cataract/posterior segment surgery, secondary intraocular lens, and trabeculectomy) were required more in Groups B and C. After regrafting, 7 eyes were salvaged and 7 (3 in Group B and 4 in Group C) resulted in phthisis bulbi. Thus, tectonic outcome was achieved in 80% of cases.

Conclusions:

Sclerokeratoplasty is an effective tectonic treatment for restoring the globe anatomy in severe corneoscleral infection. Outcome depends on involvement of scleral quadrants, graft size, and severity of disease. Subsequent regrafting procedures are required to overcome reinfection of the primary graft.

Hepatitis A virus infection in an HIV-positive man with previously confirmed immunity against hepatitis A virus

A Japanese man with human immunodeficiency virus (HIV) was detected 9 years ago to have a positive titer for hepatitis A virus (HAV) immunoglobulin (Ig) G, without a history of HAV infection or vaccination. His plasma HIV RNA was well-controlled on antiretroviral therapy for more than 6 years. He developed HAV infection with subsequent reduction of the HAV IgG titer. A decreasing HAV IgG in persons living with HIV might indicate the possibility of HAV reinfection and should prompt the consideration for additional vaccination.

QuantTB - a method to classify mixed Mycobacterium tuberculosis infections within whole genome sequencing data

BACKGROUND

Mixed infections of Mycobacterium tuberculosis and antibiotic heteroresistance continue to complicate tuberculosis (TB) diagnosis and treatment. Detection of mixed infections has been limited to molecular genotyping techniques, which lack the sensitivity and resolution to accurately estimate the multiplicity of TB infections. In contrast, whole genome sequencing offers sensitive views of the genetic differences between strains of M. tuberculosis within a sample. Although metagenomic tools exist to classify strains in a metagenomic sample, most tools have been developed for more divergent species, and therefore cannot provide the sensitivity required to disentangle strains within closely related bacterial species such as M. tuberculosis. Here we present QuantTB, a method to identify and quantify individual M. tuberculosis strains in whole genome sequencing data. QuantTB uses SNP markers to determine the combination of strains that best explain the allelic variation observed in a sample. QuantTB outputs a list of identified strains, their corresponding relative abundances, and a list of drugs for which resistance-conferring mutations (or heteroresistance) have been predicted within the sample.

RESULTS

We show that QuantTB has a high degree of resolution and is capable of differentiating communities differing by less than 25 SNPs and identifying strains down to 1× coverage. Using simulated data, we found QuantTB outperformed other metagenomic strain identification tools at detecting strains and quantifying strain multiplicity. In a real-world scenario, using a dataset of 50 paired clinical isolates from a study of patients with either reinfections or relapses, we found that QuantTB could detect mixed infections and reinfections at rates concordant with a manually curated approach.

CONCLUSION

QuantTB can determine infection multiplicity, identify hetero-resistance patterns, enable differentiation between relapse and re-infection, and clarify transmission events across seemingly unrelated patients - even in low-coverage (1×) samples. QuantTB outperforms existing tools and promises to serve as a valuable resource for both clinicians and researchers working with clinical TB samples.

PD-1 blockade promotes immune memory following Plasmodium berghei ANKA reinfection

The establishment of malaria immune memory is slow, incomplete, and short-lived. The mechanisms underpinning the generation and maintenance of anti-malarial immune memory remain unclear. This study evaluated the possible role of programmed cell death-1 (PD-1) in the establishment of malaria immune memory. Following infection by Plasmodium berghei ANKA (Pb ANKA) we compared natural immunity, acquired immunity, and immune memory between WT and mice lacking PD-1 via monoclonal antibody treatment. We found that parasitemia levels were significantly lower in the PD-1 knockdown group. After PD-1 elimination, dendritic cells, Th1, and T-follicular helper cells increased significantly. In addition, memory T, long-lived plasma cells, and serum antibody production also increased significantly. Therefore, PD-1 elimination induced stronger natural and acquired immune responses and enhanced immune memory against the parasite.

Recurrent tuberculosis in patients infected with the predominant Mycobacterium tuberculosis outbreak strain in Denmark. New insights gained through whole genome sequencing

OBJECTIVES

Recurrent tuberculosis (TB) is defined by more than one TB episode per patient and is caused by reinfection with a new M. tuberculosis (Mtb) strain or relapse with the previous strain. In Denmark, a major TB outbreak caused by one specific Mtb genotype "DKC2" is ongoing. Of the 892 patients infected with DKC2 between 1992 and 2014, 32 had recurrent TB with 67 TB episodes in total.

METHODS

The 32 cases were evaluated in terms of number of single-nucleotide polymorphism (SNP) differences and time between episodes derived from whole-genome sequencing data.

RESULTS

For four TB cases, the subsequent episodes could be confirmed as relapse and for one case as reinfection. Eight cases with SNP differences <6, theoretically indicating relapse, could be classified as likely reinfections based on phylogenetic analysis in combination with geographical data. Subsequent TB episodes for the remaining 19 cases could not be classified as relapse or reinfection even though they all had a SNP difference of <6 SNPs.

CONCLUSIONS

In newer studies, investigating recurrent TB with the use of WGS, the number of SNPs has been used to distinguish between relapse and reinfection. The algorithm proposed for this is not valid in the Danish TB outbreak setting as our findings challenge the interpretation of few SNP differences as representing relapse. However, when including phylogenetic analysis and geographical data in the analysis, classification of 13 of the 32 cases were possible.

Schistosoma haematobium infection morbidity, praziquantel effectiveness and reinfection rate among children and young adults in Gabon

Background

Sub-Saharan Africa carries most of the global burden of schistosomiasis. To optimize disease control and reduce morbidity, precise data are needed for control measures adapted to the local epidemiological situation. The objective of this study is to provide baseline information on schistosomiasis dynamics, including praziquantel (PZQ) treatment outcome in children and young adults living in the vicinity of Lambaréné, Gabon.

Methods

Eligible volunteers were included into a prospective longitudinal study. Urine filtration technique was used to detect eggs in urine for schistosomiasis diagnosis. Subjects were treated with 60 mg of PZQ once per month for three consecutive months, and the outcome was assessed by cure rate (CR) and egg reduction rate (ERR).

Results

A total of 328 volunteers were enrolled in the study with a mean (± SD) age of 12.2 ± 4.7 years-old. The female-to-male ratio was 0.99. Out of 258 participants in total, 45% had schistosomiasis during the survey and 43% presented with heavy infections. The incidences of haematuria and schistosomiasis were 0.11 and 0.17 person-years, respectively. After the first and third dose of PZQ, overall ERR of 93% and 95% were found, respectively; while the CR were 78% and 88%, respectively. Both ERR (100 vs 88%) and CR (90 vs 68%) were higher among females than males after the first dose. The CR increased for both groups after the third dose to 95% and 80%, respectively. After the first PZQ dose, ERR was higher for heavy compared to light infections (94 vs 89%), while the CR was higher for light than for heavy infections (87 vs 59%). After the third PZQ dose, ERR increased only for light infections to 99%, while CR increased to 98% and 75% for light and for heavy infections, respectively. The reinfection rate assessed at a mean of 44.6 weeks post-treatment was 25%.

Conclusions

The prevalence of schistosomiasis is moderate in communities living in the vicinity of Lambaréné, where a subpopulation with a high risk of reinfection bears most of the burden of the disease. To improve schistosomiasis control in this scenario, we suggest education of these high-risk groups to seek themselves a one-year PZQ treatment.

Trial registration clinicaltrials.gov Identifier NCT 02769103. Registered 11 May 2016, retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT02769013

Limited impact of influenza A virus vaccination of piglets in an enzootic infected sow herd

Recent studies have questioned the effect of maternal derived antibodies (MDAs) to protect piglets against infection with influenza A virus (IAV). The lack of protection against IAV infections provided by MDAs has encouraged alternative vaccination strategies targeting young piglets in an attempt to stimulate an early antibody response. There is a lack of studies documenting the efficacy of piglet vaccination. In the present study, we monitored a group of vaccinated and non-vaccinated piglets in a Danish sow herd that initiated piglet vaccination with ¼ dose of an inactivated swine influenza vaccine at the time of castration (day 3-4). A total of 160 piglets from 11 sows were included and either vaccinated with 0.5 mL inactivated swine influenza vaccine or sham-vaccinated. From week 0 until week 6, all included piglets were clinically examined and nasal swapped once per week and weighed at weeks 0, 3 and 6. Blood samples were collected from sows at week 0 and from piglets at week 3. Vaccination of piglets had limited effect on clinical signs, body weight, antibody development and viral shedding, within the first 6 weeks of life. At least 50% of all pigs of each treatment group tested positive for IAV at week 2, and very early onset of IAV shedding was observed. In total, 18 pigs were IAV positive in nasal swabs for more than one consecutive sampling time indicating prolonged shedding and 14 pigs were IAV positive with negative samplings in between indicating re-infection with the same IAV strain.

Tissue dissemination and humoral response after experimental reinfection with atypical Toxoplasma gondii strains obtained from congenital human toxoplasmosis in Brazil

The paradigm that Toxoplasma gondii infection generates sterilizing protective immunity was broken by case studies in which reinfections were observed in immunocompetent pregnant women in the chronic phase of toxoplasmosis. Since then, several murine models have suggested that immunoprotection against a previous T. gondii infection may be violated after reinfection with strains of different genotypes. This study aimed to evaluate the dissemination of the parasite after reinfection with the virulent TgCTBr9 and EGS strains in BALB/c mice chronically infected with the avirulent TgCTBr5 strain. Three mice were euthanized at 2, 4, 8, 12, 24 and 48 h post challenge (p.c.) and at 7, 14 and 30 days p.c. Intestines, mesenteric lymph nodes, lungs and brains were collected for PCR-RFLP. Blood samples were collected to measure total IgG, IgG1 and IgG2a by ELISA. The reinfected animals survived and presented reduced morbidity after challenge with the virulent strains. Mice challenged with the TgCTBr9 strain showed a slight increase in anti-T. gondii IgG1. The spread of the TgCTBr5 strain was observed to occur earlier than the dissemination of the virulent TgCTBr9 or EGS strains. The TgCTBr9 strain was observed in the mesenteric lymph node at 7 days post challenge (d.p.c.); in the intestine and lungs at 14 d.p.c.; and in the brain at 30 d.p.c. EGS strain was demonstrated in the mesenteric lymph node and lung at 7 d.p.c and in the intestine and brain at a later time point. The immune response promoted by the primary infection with the avirulent strain (TgCTBr5) protected the animals from death after challenge with the virulent strains (TgCTBr9 or EGS).

Hepatitis C virus treatment in people who inject drugs (PWID) in Bangladesh

BACKGROUND

Given the considerable social marginalization experienced by people who inject drugs (PWID), treatment of hepatitis C virus (HCV) in this population presents unique challenges. This study assessed the feasibility of treating HCV infection with direct-acting antiviral (DAA) medications among PWID receiving harm reduction services from a Drop-in-Center in Dhaka, Bangladesh.

METHODS

In this prospective study conducted between December 2016 and May 2018, 200 PWID with either recent injecting drug use (i.e., within the previous two months) or a history of injecting drug use and are currently receiving opioid substitution therapy were recruited. Blood was collected to conduct relevant laboratory tests. Eligible PWID who tested positive for HCV RNA (n = 55), were provided daily daclatasvir (60 mg) and sofosbuvir (400 mg) for 12 weeks after which adherence level, sustained virologic response (SVR), and reinfection were assessed.

RESULTS

At baseline, 40% (n = 79) of the 200 participants recruited to the study tested positive for antibodies to HCV and 34% (n = 68) had detectable HCV RNA in their blood. Of 55 eligible PWID who initiated treatment, 93% (n = 51) completed treatment while 87% (n = 48) were available for follow-up SVR assessment, all of whom achieved SVR. Thus, intent-to-treat SVR was 87% and the modified intent-to-treat SVR was 100% with one reinfection (4•2 cases per 100 person-years). Further, 75% (i.e., 41 out of the 55 participants) were at least 90% adherent to therapy.

CONCLUSION

Our findings strongly suggest that HCV treatment using sofosbuvir+daclatasvir for PWID enrolled in existing harm reduction programs in Bangladesh is feasible but may require additional interventions such as Opioid Substitution Therapy, intense follow up by outreach workers, and services and counselling provided by full time clinicians.

Comparison of Characteristics of Streptococcus dysgalactiae subsp. equisimilis Isolates Causing Repetitive vs Single Infections

No study has described Streptococcus dysgalactiae subsp. equisimilis (SDSE) isolates that cause repetitive infections (recurrence and reinfection). We compared the microbiological characteristics of SDSE causing repetitive infections with those causing single infections. Three patients with invasive infections were identified based on their medical records, and multiple SDSE isolates were collected at intervals over three weeks, using a laboratory repository. Isolates from 12 patients with single-episode infections served as controls. Six isolates were collected from three patients with first and second episodes of infection. All isolates causing either repetitive or single-episode infection were subjected to emm typing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and random amplified polymorphic DNA (RAPD) analyses. Amplification of five virulence genes (sicG, prtF1, prtF2, lmb, and cbp), biofilm formation (BF), and cell invasion abilities (CIAs) were measured as virulent phenotypes. We observed close genetic similarities in the data obtained by emm typing, MLST, PFGE, and RAPD in four isolates from two patients, suggesting recurrence, whereas two isolates from one patient indicated genetic differences in these data, suggesting re-infection. The presence of the five virulence genes and the BF and CIA measurements appeared not to contribute to repetitive infections, compared with isolates causing single-episode infection. In conclusion, clinicians encountering patients with repetitive infections should be aware of both possibilities: recurrence with closely related strains and reinfection with different strains.

Inference from the analysis of genetic structure of Helicobacter pylori strains isolates from two paediatric patients with recurrent infection

Background

Helicobacter pylori recurrence after successful eradication is an important problem. Children are particularly vulnerable to reinfection, by intrafamilial transmission which facilitates the acquisition or recombination of new genetic information by this bacterium. We investigated the evolutionary dynamics of 80 H. pylori strains isolated from two paediatric patients with recurrent infection (recrudescence and reinfection).

Results

We characterized the virulence genes vacA (s1, m1, s2, and m2), cagA, cagE, and babA2 and performed multilocus sequence typing (MLST) on 7 housekeeping genes (atpA, efp, ureI, ppa, mutY, trpC, and yphC) to infer the evolutionary dynamics of the H. pylori strains through phylogenetic and genealogic inference analyses, genetic diversity analysis and the exploration of recombination events during recurrent infections. The virulence genotype vacAs1m1/cagA+/cagE+/babA2 was present at a high frequency, as were the EPIYA motifs EPIYA-A, −B and -C. Furthermore, the housekeeping genes of the H. pylori strains exhibited high genetic variation, comprising 26 new alleles and 17 new Sequence Type (ST). In addition, the hpEurope (76.5%) and hspWAfrica (23.5%) populations predominated among the paediatric strains. All strains, regardless of their ancestral affiliation, harboured western EPIYA motifs.

Conclusions

This study provides evidence of the evolutionary dynamics of the H. pylori strains in two paediatric patients during recrudescence and reinfection events. In particular, our study shows that the strains changed during these events, as evidenced by the presence of different STs that emerged before and after treatment; these changes may be due to the accumulation of mutations and recombination events during the diversification process and recolonization of the patients by different genotypes.

Electronic supplementary material

The online version of this article (10.1186/s12866-019-1554-z) contains supplementary material, which is available to authorized users.

Chronic hepatitis E after kidney transplantation with an antibody response suggestive of reinfection: a case report

Background

Hepatitis E virus (HEV) infection is now recognized as a major cause of acute hepatitis worldwide. HEV specific antibodies develop shortly after infection and are thought to confer protection.

Case presentation

We report an immunocompromised patient who developed chronic HEV infection despite the presence of high level antibodies. HEV infection was detected using RT-PCR upon diagnostic evaluation due to increased liver enzymes. Upon retrospective analysis of stored serum samples we found that the patient was HEV RNA positive since 7 months. Chronic HEV infection was successfully treated with ribavirin.

Conclusions

In conclusion, the patient suffered from a chronic course of HEV infection, which was successfully treated with ribavirin. Our case underlines the importance of RT-PCR for HEV diagnostics in immunosuppressed patients and supports the notion that HEV antibodies do not confer universal protection. Counseling patients at risk for chronic HEV infection seems advisable. The role of the humoral and T-cell mediated immune response in cases of HEV reinfection deserves further study.

Low rate of reinfection among a cohort of people who use drugs successfully treated for hepatitis C virus infection in Vancouver, Canada

INTRODUCTION

Concerns about reinfection may be limiting HCV treatment uptake among people who use drugs (PWUD), with rates of 17.1/100 person-years in some cohorts. The aim of this study was to evaluate reinfection following successful treatment for hepatitis C virus infection in a cohort of people who inject drugs in Vancouver, Canada.

METHODS

We identified a cohort of HCV-infected PWUD treated at our centre. Following cure, patients were maintained in long-term follow-up in a multidisciplinary program to address their medical, psychological, social, and addiction-related needs. HCV RNA measurements were repeated every 6 months, and ongoing drug use was documented. The primary outcome of this analysis was the occurrence of reinfection.

RESULTS

243 recent PWUD (use within 6 months of treatment initiation) have achieved SVR and maintained in long-term follow-up. Ongoing drug use post-treatment was documented in 195 individuals. Key characteristics: mean age 53 years, 25% female, 78% treatment naïve, 17% cirrhotic. Reinfection occurred in 4 cases, all in patients with ongoing drug use. This incidence was 1.05/100 [95% 0.8-5.2] person years based on 379 person-years of follow-up in individuals currently using drugs.

CONCLUSION

Approaches including long-term maintenance in multidisciplinary care may optimize long-term outcomes of HCV treatment in PWUD.

Hepatitis C virus recurrence in two patients who achieved sustained viral response with interferon-free direct-acting antiviral therapy: reinfection or relapse?

We experienced two patients with chronic hepatitis C (HCV) in whom it was difficult to distinguish between relapse and reinfection after interferon-free direct-acting antiviral (DAA) therapy. Case 1 was a 55-year-old man infected with HCV genotype 1b, at 5.6 log IU/mL, with a history of injecting drug use. He was treated with ombitasvir/paritaprevir/ritonavir for 12 weeks. After DAA therapy, recurrent HCV showed the genotype 2a differed from the baseline genotype. Close examination for baseline sample showed that he was coinfected with HCV genotype 1b and 2a. Case 2 was a 60-year-old woman with HCV2b, at 5.7 log IU/mL. She was treated with sofosbuvir/ribavirin for 12 weeks and achieved a sustained virological response (SVR) at 24 weeks. Even after SVR24, her serum alanine aminotransferase levels remained fluctuated. HCV RNA was detected again at 48 weeks. She had a sexual partner who was also infected with HCV2b. The phylogenetic tree analysis revealed a high degree of homology among the three strains: pre- and post-HCV treatment, and her partner. After HCV recurrence, HCV RNA level decreased spontaneously below the limit of detection and serum ALT levels normalized. It is important to make a precise diagnosis regarding reemerged HCV after DAA therapy.

Duration of antibiotic treatment and risk of recurrence after surgical management of orthopaedic device infections: a multicenter case-control study

Background

Device-related infections in orthopaedic and trauma surgery are a devastating complication with substantial impact on morbidity and mortality. Systemic suppressive antibiotic treatment is regarded an integral part of any surgical protocol intended to eradicate the infection. The optimal duration of antimicrobial treatment, however, remains unclear. In a multicenter case-control study, we aimed at analyzing the influence of the duration of antibiotic exposure on reinfection rates 1 year after curative surgery.

Methods

This investigation was part of a federally funded multidisciplinary network project aiming at reducing the spread of multi-resistant bacteria in the German Baltic region of Pomerania. We herein used hospital chart data from patients treated for infections of total joint arthroplasties or internal fracture fixation devices at three academic referral institutions. Subjects with recurrence of an implant-related infection within 1 year after the last surgical procedure were defined as case group, and patients without recurrence of an implant-related infection as control group. We placed a distinct focus on infection of open reduction and internal fixation (ORIF) constructs. Uni- and multivariate logistic regression analyses were employed for data modelling.

Results

Of 1279 potentially eligible patients, 269 were included in the overall analysis group, and 84 contributed to an extramedullary fracture-fixation-device sample. By multivariate analysis, male sex (odds ratio [OR] 2.06, 95% confidence interval [CI] 1.08 to 3.94, p = 0.029) and facture fixation device infections (OR 2.05, 95% CI 1.05 to 4.02, p = 0.036) remained independent predictors of reinfection. In the subgroup of infected ORIF constructs, univariate point estimates suggested a nearly 60% reduced odds of reinfection with systemic fluoroquinolones (OR 0.42, 95% CI 0.04 to 2.46) or rifampicin treatment (OR 0.41, 95% CI 0.08 to 2.12) for up to 31 days, although the width of confidence intervals prohibited robust statistical and clinical inferences.

Conclusion

The optimal duration of systemic antibiotic treatment with surgical concepts of curing wound and device-related orthopaedic infections is still unclear. The risk of reinfection in case of infected extramedullary fracture-fxation devices may be reduced with up to 31 days of systemic fluoroquinolones and rifampicin, although scientific proof needs a randomized trial with about 1400 subjects per group. Concerted efforts are needed to determine which antibiotics must be applied for how long after radical surgical sanitation to guarantee sustainable treatment success.

Comparison of msp genotyping and a 24 SNP molecular assay for differentiating Plasmodium falciparum recrudescence from reinfection

Background

Current World Health Organization guidelines for conducting anti-malarial drug efficacy clinical trials recommend genotyping Plasmodium falciparum genes msp1 and msp2 to distinguish recrudescence from reinfection. A more recently developed potential alternative to this method is a molecular genotyping assay based on a panel of 24 single nucleotide polymorphism (SNP) markers.

Methods

Performance parameters of these two genotyping methods were compared using data from two recently completed drug efficacy trials. Blood samples from two anti-malarial therapeutic trials were analysed by both msp genotyping and the 24 SNP assay. Additionally, to conserve time and resources, the statistical program R was used to select the most informative SNPs for a set of unrelated Malawian samples to develop a truncated SNP-based assay for the region surrounding Blantyre, Malawi. The ability of this truncated assay to distinguish reinfection from recrudescence when compared to the full 24 SNP assay was then analysed using data from the therapeutic trials.

Results

A total of 360 samples were analysed; 66 for concordance of msp and SNP barcoding methodologies, and 294 for assessing the most informative of the 24 SNP markers. SNP genotyping performed comparably to msp genotyping, with only one case of disagreement among the 50 interpretable results, where the SNP assay identified the sample as reinfection and the msp typing as recrudescence. Furthermore, SNP typing was more robust; only 6% of samples were uninterpretable by SNP typing, compared to 19.7% when msp genotyping was used. For discriminating reinfection from recrudescence, a truncated 6 SNP assay was found to perform at 95.1% the accuracy of the full 24 SNP bar code.

Conclusions

The use of SNP analysis has similar sensitivity to the standard msp genotyping in determining recrudescence from reinfection. Although more expensive, SNP typing is faster and less work intensive. Limiting the assay to those SNPs most informative in the geographical region of interest may further decrease the workload and the cost, making this technique a feasible and affordable alternative in drug efficacy trials.

Electronic supplementary material

The online version of this article (10.1186/s12936-019-2695-0) contains supplementary material, which is available to authorized users.

Short-term effects of extreme meteorological factors on childhood hand, foot, and mouth disease reinfection in Hefei, China: A distributed lag non-linear analysis

BACKGROUND

Hand, foot, and mouth disease (HFMD) is a major public health issue in China with a high burden of reinfection. Previous studies presented evidence of the relationship between meteorological factors and HFMD incidence, but no study examined the effects of extreme meteorological factors on HFMD reinfection.

METHODS

Daily HFMD reinfection counts and meteorological data of Hefei city were collected from 2011 to 2016. A distributed lag non-linear model was used to quantify the effects of extreme weather (wind speed, sunshine duration, and precipitation) on HFMD reinfection. All effects were presented as relative risk (RR), with 90th or 10th percentiles of meteorological variables compare with their median values. Confounding factors, such as mean temperature, relative humidity, day of week, and long-term trend were controlled.

RESULTS

A total of 4873 HFMD reinfection cases aged 0-11 years were reported. Extremely high precipitation, low wind speed, and low sunshine duration increased HFMD reinfection risk. The effect of extremely high precipitation was greatest at 8 days lag (RR = 1.01, 95%CI: 1.00-1.02). Extremely low wind speed and low sunshine increased 19% (RR = 1.19, 95%CI: 1.09-1.32) and 12% (RR = 1.12, 95%CI: 1.00-1.26) risk at lag 0-12 days, respectively. By contrast, extremely high wind speed and high sunshine duration exerted certain protective effects on HFMD reinfection at lag 0-12 days (RR = 0.76, 95%CI: 0.66-0.88; RR = 0.88, 95%CI: 0.79-0.99, respectively). Subgroup analyses showed that nursery children were the most sensitive people to the extreme wind speed and sunshine duration. Children aged 4-11 years appeared to be more susceptible to extreme sunshine duration than children aged <3 years.

CONCLUSION

The present study provides evidence that extreme meteorological factors exert delayed effects on HFMD reinfection. Developing an early warning system is necessary for the protection of children from harm due to extreme meteorological factors.

Strategies to Reduce Hepatitis C Virus Reinfection in People Who Inject Drugs

Reinfection after direct-acting antiviral therapy may pose a challenge to hepatitis C virus elimination efforts. Reinfection risk is cited as a reason for not offering treatment to people who inject drugs. As treatment scale-up expands among populations with risks for reacquisition, acknowledgment that reinfection can and will occur is essential. Efforts to prevent and manage reinfection should be incorporated into individual- and population-level strategies. The risk of reinfection after successful treatment emphasises the need for education, harm reduction, and posttreatment surveillance. Reinfection must not be considered an impediment to treatment, if hepatitis C virus elimination is to be achieved.

Understanding and Addressing Hepatitis C Virus Reinfection Among Men Who Have Sex with Men

Hepatitis C virus reinfection rates among men who have sex with men are high. Factors associated with infection point to varied sexual and drug-related risks that could be targeted for interventions to prevent infection/reinfection. Modeling indicates that tackling increasing incidence and high reinfection rates requires high levels of hepatitis C virus treatment combined with behavioral interventions. Enhanced testing strategies and prompt retreating of reinfection may be required to promptly diagnosed reinfections. Behavioral interventions studies addressing reinfection are required. Other interventions include traditional harm reduction interventions, adapted behavioral interventions, and interventions to prevent harms related to ChemSex and other risk factors.

Probable reinfection with Legionella pneumophila - A case report

In Germany community-acquired Legionnaires' disease is usually caused by the species Legionella pneumophila. Recurrent cases of Legionnaires' disease are rarely reported and are due either to a second infection (reinfection) or a relapse of a previous case. We report a case of recurrent Legionnaires' disease in an 86-year-old female patient infected with Legionella pneumophila serogroup 1, monoclonal antibody-subtype Knoxville, sequence type unknown. Between the two disease incidents the patient had completely recovered. Legionella pneumophila was detected with the monoclonal antibody-subtype Knoxville, sequence type 182, in the drinking water of the patient's apartment. Exposure to contaminated drinking water was interrupted after the first incident exposure through the application of point-of-use water filters. The filters were later removed due to low water pressure, and the second illness occurred thereafter. It is unclear if immunological predisposition has contributed to this case of probable reinfection of Legionnaires' disease. Clinical, microbiological and epidemiological information combined suggest this is a case of reinfection of Legionnaires' disease. In cases of recurrent Legionnaires' disease complete collection of patient and water samples is necessary to differentiate relapse from reinfection cases, to implicate the source of infection and to gain more evidence for the role of immunological predisposition.

Study protocol of the iMPaCT project: a longitudinal cohort study assessing psychological determinants, sexual behaviour and chlamydia (re)infections in heterosexual STI clinic visitors

Background

Chlamydia trachomatis (chlamydia), the most commonly reported sexually transmitted infection (STI) in the Netherlands, can lead to severe reproductive complications. Reasons for the sustained chlamydia prevalence in young individuals, even in countries with chlamydia screening programs, might be the asymptomatic nature of chlamydia infections, and high reinfection rates after treatment. When individuals are unaware of their infection, preventive behaviour or health-care seeking behaviour mostly depends on psychological determinants, such as risk perception. Furthermore, behaviour change after a diagnosis might be vital to reduce reinfection rates. This makes the incorporation of psychological determinants and behaviour change in mathematical models estimating the impact of interventions on chlamydia transmission especially important. Therefore, quantitative real-life data to inform these models is needed.

Methods

A longitudinal cohort study will be conducted to explore the link between psychological and behavioural determinants and chlamydia (re)infection among heterosexual STI clinic visitors aged 18–24 years. Participants will be recruited at the STI clinics of the public health services of Amsterdam, Hollands Noorden, Kennemerland, and Twente. Participants are enrolled for a year, and questionnaires are administrated at four time points: baseline (before an STI consultation), three-week, six-month and at one-year follow-up. To be able to link psychological and behavioural determinants to (re)infections, participants will be tested for chlamydia at enrolment and at six-month follow-up. Data from the longitudinal cohort study will be used to develop mathematical models for curable STI incorporating these determinants to be able to better estimate the impact of interventions.

Discussion

This study will provide insights into the link between psychological and behavioural determinants, including short-term and long-term changes after diagnosis, and chlamydia (re)infections. Our mathematical model, informed by data from the longitudinal cohort study, will be able to estimate the impact of interventions on chlamydia prevalence, and identify and prioritise successful interventions for the future. These interventions could be implemented at STI clinics tailored to psychological and behavioural characteristics of individuals.

Trial registration

Dutch Trial Register NTR-6307. Retrospectively registered 11-nov-2016.

Hepatitis C virus reinfection after successful treatment with direct-acting antiviral therapy in a large population-based cohort

BACKGROUND & AIMS

Direct-acting antiviral therapies (DAA) are an important tool for hepatitis C virus (HCV) elimination. However, reinfection among people who inject drugs (PWID) may hamper elimination targets. Therefore, we estimated HCV reinfection rates among DAA-treated individuals, including PWID.

METHODS

We analyzed data from the British Columbia Hepatitis Testers Cohort which included ∼1.7 million individuals screened for HCV in British Columbia, Canada. We followed HCV-infected individuals treated with DAAs who achieved a sustained virologic response (SVR) and had ≥1 subsequent HCV RNA measurement to April 22nd, 2018. Reinfection was defined as a positive RNA measurement after SVR. PWID were identified using a validated algorithm and classified based on recent (<3 years) or former (≥3 years before SVR) use. Crude reinfection rates per 100 person-years (PYs) were calculated. Poisson regression was used to model adjusted incidence rate ratios (IRRs) and 95% CIs.

RESULTS

Of 4,114 individuals who met the inclusion criteria, most were male (n = 2,692, 65%), born before 1965 (n = 3,411, 83%) and were either recent (n = 875, 21%) or former PWID (n = 1,793, 44%). Opioid-agonist therapy (OAT) was received by 19% of PWID. We identified 40 reinfections during 2,767 PYs. Reinfection rates were higher among recent (3.1/100 PYs; IRR 6.7; 95% CI 1.9-23.5) and former PWID (1.4/100 PYs; IRR 3.7; 95% CI 1.1-12.9) than non-PWID (0.3/100 PYs). Among recent PWID, reinfection rates were higher among individuals born after 1975 (10.2/100 PYs) and those co-infected with HIV (5.7/100 PYs). Only one PWID receiving daily OAT developed reinfection.

CONCLUSIONS

Population-level reinfection rates remain elevated after DAA therapy among PWID because of ongoing exposure risk. Engagement of PWID in harm-reduction and support services is needed to prevent reinfections.

LAY SUMMARY

Direct-acting antivirals are an effective tool for the treatment of hepatitis C virus, enabling the elimination of the virus. However, some patients who have been successfully treated with direct-acting antivirals are at risk of reinfection. Our findings showed that the risk of reinfection was highest among people with recent injection drug use. Among people who inject drugs, daily use of opioid-agonist therapy was associated with a lower risk of reinfection.

Reinfection of urogenital schistosomiasis in pre-school children in a highly endemic district in Northern Zimbabwe: a 12 months compliance study

Background

In light of the shift to aiming for schistosomiasis elimination, the following are needed: data on reinfection patterns, participation, and sample submission adherence of all high-risk age groups to intervention strategies. This study was conducted to assess prevalence, reinfections along with consecutive participation, sample submission adherence, and effect of treatment on schistosomiasis prevalence in children aged five years and below in an endemic district in Zimbabwe, over one year.

Methods

The study was conducted from February 2016–February 2017 in Madziwa area, Shamva district. Following community mobilisation, mothers brought their children aged 5 years and below for recruitment at baseline and also urine sample collection at baseline, 3, 6, 9 and 12 months follow up surveys. At each time point, urine was tested for urogenital schistosomiasis by urine filtration and children found positive received treatment. Schistosoma haematobium prevalence, reinfections as well as children participation, and urine sample submission at each visit were assessed at each time point for one year.

Results

Of the 535 children recruited from the five communities, 169 (31.6%) participated consecutively at all survey points. The highest mean number of samples submitted was 2.9 among communities and survey points. S. haematobium prevalence significantly reduced from 13.3% at baseline to 2.8% at 12 months for all participants and from 24.9% at baseline to 1.8% at 12 months (P <  0.001) for participants coming at all- time points. Among the communities, the highest baseline prevalence was found in Chihuri for both the participants coming consecutively (38.5%, 10/26) and all participants (20.4%, 21/103). Reinfections were significantly high at 9 months follow up survey (P = 0.021) and in Mupfure (P = 0.003). New infections significantly decreased over time (P <  0.001). Logistic regression analysis showed that the risk of acquiring schistosomiasis was high in some communities (P <  0.05).

Conclusions

S. haematobium infections and reinfections are seasonal and depend on micro-geographical settings. The risk of being infected with schistosomes in pre-school aged children increases with increasing age. Sustained treatment of infected individuals in a community reduces prevalence overtime. Participation compliance at consecutive visits and sample submission adherence are important for effective operational control interventions.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0483-7) contains supplementary material, which is available to authorized users.

Epidemiological characteristics and influential factors of hand, foot, and mouth disease reinfection in Wuxi, China, 2008-2016

Background

Hand, foot, and mouth disease (HFMD) is a viral disease caused by human enteroviruses. Although HFMD reinfection is common, studies investigating this phenomenon are insufficient.

Methods

The present study focused on HFMD reinfection in Wuxi from 2008 to 2016 using surveillance system data.

Results

Of 107,677 cases included in the study, 6470 cases were classified as reinfections. The overall reinfection rate was 6.01% (6.37% male and 5.48% female patients), which decreased with increasing age (χ² = 1125.477, p < 0.001). The rate was 6.17 and 5.79% in urban and rural areas, respectively, and 7.83 and 5.98% of the cases were severe and mild, respectively. Multivariate logistic regression analysis showed that male sex, younger age, residence in an urban area, and severe disease were risk factors for HFMD reinfection. The case-severity rate in secondary infection cases was lower than that in non-reinfection cases (odds ratio 0.675, 95% confidence interval 0.526–0.866).

Conclusions

Boys younger than 4 years of age living in urban areas were more prone to reinfection. Specific health education and intervention should be developed to protect these susceptible populations.

Not again! Effect of previous test results, age group and reason for testing on (re-)infection with Chlamydia trachomatis in Germany

Background

Infection with Chlamydia trachomatis (Ct) is the most commonly reported sexually transmitted infection in Europe. In Germany, Ct screening is offered free of charge to pregnant women since 1995 and to women < 25 years of age since 2008. For symptomatic individuals, testing is covered by statutory health insurance. Study results have shown that repeat Ct infection occurs in 10–20% of previously infected women and men. Our aim was to describe persons tested for Ct and to investigate the determinants of (repeat) Ct infection in women and men in Germany.

Methods

We analysed Ct test results from men and women tested between 2008 and 2014 in laboratories participating in the German Chlamydia trachomatis Laboratory Sentinel surveillance. Reinfection was defined as at least 2 positive laboratory tests within more than 30 days. We performed logistic regression stratified by sex and, for women, reason for testing to determine the effect of previous test results and age group on subsequent test results.

Results

In total, 2,574,635 Ct tests could be attributed to 1,815,494 women and 123,033 men. 5% of women and 14% of men tested positive at least once. 15–19- and 20–24-year-old women tested positive at least once respectively in 6.8 and 6.0%, while men respectively in 16.6 and 21.2%. Altogether, 23.1% of tested women and 11.9% of tested men were tested repeatedly between 2008 and 2014. Among those who previously tested positive, reinfection occurred in 2.0% of women and 6.6% of men. Likelihood to be tested Ct positive was higher in women and men with a positive Ct test in the past compared to previously tested Ct negative, odds ratios 4.7 and 2.6 (p < 0.01) respectively. Odds ratios ranged by age group and test reason.

Conclusion

A history of Ct infection increased the likelihood of infection with Ct in women and men taking into account the result of the previous test. Health education, safer sex and treatment of partners are necessary for women and men who have tested positive to prevent reinfection and complications and to interrupt the chain of transmission. To identify potential reinfection repeat testing after treatment should be performed.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3323-2) contains supplementary material, which is available to authorized users.