Imaging patterns of Pneumocystis jirovecii pneumonia in HIV-positive and renal transplant patients - a multicentre study

OBJECTIVES

To investigate differences in chest computed tomography (CT) and chest radiographs (CXRs) of Pneumocystis jirovecii pneumonia (PJP) between renal transplant recipients (RTRs) and human immunodeficiency virus (HIV)-positive patients.

METHODS

From 2005 to 2012, 84 patients with PJP (RTR n = 24; HIV n = 60) were included in this retrospective multicentre study. Written informed consent was obtained. CT scans and CXRs were recorded within 2 weeks after the onset of symptoms. PJP diagnosis was confirmed either by cytology/histology or successful empirical treatment. Two blinded radiologists analysed the conventional chest films and CT images, and recorded the radiological lung parenchyma patterns, lymph node enlargement and pleural pathologies (pneumothorax, effusion). The radiological features of the two subgroups were compared.

RESULTS

Consolidations and solid nodules prevailed on CT in RTRs (91.7 ± 5.6% vs 58.3 ± 6.4% with HIV, p = 0.019 and 91.7 ± 5.6% vs 51.6 ± 6.5% with HIV, p = 0.005). HIV-positive patients with PJP showed more atelectasis (41.7 ± 6.4% vs 4.2 ± 4.1% in RTRs, p = 0.017) and hilar lymph node enlargement (23.3 ± 5.5% vs 0.0 ± 0.0% in RTRs, p = 0.088). Ground glass opacification was found in all cases. Pneumothorax was a rare complication, occurring in 3% of the HIV-positive patients; no pneumothorax was found in the RTRs. On CXR, the basal lungs were more affected in HIV-positive patients as compared with RTRs (p = 0.024).

CONCLUSIONS

PJP on CT differs substantially between RTRs and HIV-positive patients. Physicians should be aware of such differences in order not to delay treatment, particularly in renal transplant recipients.

Cefepime neurotoxicity: thresholds and risk factors. A retrospective cohort study

OBJECTIVES

Toxic serum cefepime trough concentrations are not well defined in the current literature. We aimed to define a more precise plasma trough concentration threshold for this antibiotic's neurological toxicity and to identify individuals at risk for developing neurotoxic side effects.

METHODS

Retrospective study including all individuals who underwent cefepime therapeutic drug monitoring (TDM) between 2013 and 2017. Individuals with cefepime concentrations other than trough were excluded. The primary outcome was to assess the incidence of neurotoxicity and its relationship with cefepime plasma trough concentrations. Secondary outcomes were the relationship of renal function, cefepime daily dose, age, and cerebral and general co-morbidities with the occurrence of neurotoxicity. We also compared the mortality rate during hospitalization in individuals with and without neurotoxicity, and the possible impact of neuroprotective co-medications on outcomes.

RESULTS

Cefepime concentrations were determined in 584 individuals. Among 319 individuals with available trough concentrations included, the overall incidence of neurotoxicity was 23.2% (74 of 319 individuals). Higher cefepime plasma trough concentrations were significantly associated with risk of neurotoxicity (no neurotoxicity 6.3 mg/L (interquartile range (IQR) 4.1-8.6) versus with neurotoxicity 21.6 mg/L (IQR 17.0-28.6), p <0.001). Individuals with presumed cefepime neurotoxicity had a significantly lower renal function (estimated glomerular filtration rate 82.0 mL/min/1.73 m² (IQR 45.0-105.0) versus 35.0 mL/min/1.73 m² (IQR 23.3-53.3], p <0.001), and significantly higher in-hospital mortality (19 (7.8%) versus 26 (35.1%) individuals, p <0.001). No neurotoxic side effects were seen below a trough concentration of 7.7 mg/L. Levels ≥38.1 mg/L always led to neurological side effects.

CONCLUSION

In individuals with risk factors for cefepime neurotoxicity, such as renal insufficiency, TDM should be systematically performed, aiming at trough concentrations <7.5 mg/L.

Gradual in vitro Evolution of Cefepime Resistance in an ST131 Escherichia coli Strain Expressing a Plasmid-Encoded CMY-2 β-Lactamase

Background

In a previous report, a clinical ST131 Escherichia coli isolate (Ec-1),producing a plasmid-encoded AmpC β-lactamase CMY-2, evolved in vivo under cefepime (FEP) treatment to the FEP-resistant Ec-2 strain expressing an extended-spectrum β-lactamase CMY-33. To compare factors responsible for in vitro and in vivo FEP resistance, we reproduced in vitro FEP resistance evolution in Ec-1.

Methods

FEP-resistant mutants were generated by subjecting Ec-1 (FEP MIC = 0.125 mg/L) to sub-inhibitory concentrations of FEP. MICs were obtained by broth microdilution or Etest. Strains were sequenced on an Illumina HiSeq platform. Transcriptional levels and plasmid copy numbers were determined by real-time PCR. Outer membrane proteins (OMPs) were extracted and separated by SDS-PAGE. Growth kinetics was evaluated by measuring OD₄₅₀.

Results

The CMY-2 expressed by Ec-1 evolved to a CMY-69 (strain EC-4) by an Ala294Pro substitution after 24 passages. After 30 passages, the FEP MIC increased to 256 mg/L (strain EC-32). SDS PAGE did not reveal any lack of OMPs in the mutant strains. However, bla_CMY transcription levels were up to 14-times higher than in Ec-1, which was partially explained by mutations in the upstream region of repA resulting in a higher copy number of the bla_CMY-harboring IncI1 plasmid. All mutants showed a slight growth defect but no significant difference in relative growth rates compared to Ec-1.

Conclusion

In vitro sub-inhibitory concentrations of FEP resulted in the selection of resistance mutations altering the H-10 helix of the CMY-2 and increasing the plasmid copy number. Appropriate dosing strategies may help preventing resistance evolution during treatments.

Emulating a trial of joint dynamic strategies: An application to monitoring and treatment of HIV-positive individuals

Decisions about when to start or switch a therapy often depend on the frequency with which individuals are monitored or tested. For example, the optimal time to switch antiretroviral therapy depends on the frequency with which HIV-positive individuals have HIV RNA measured. This paper describes an approach to use observational data for the comparison of joint monitoring and treatment strategies and applies the method to a clinically relevant question in HIV research: when can monitoring frequency be decreased and when should individuals switch from a first-line treatment regimen to a new regimen? We outline the target trial that would compare the dynamic strategies of interest and then describe how to emulate it using data from HIV-positive individuals included in the HIV-CAUSAL Collaboration and the Centers for AIDS Research Network of Integrated Clinical Systems. When, as in our example, few individuals follow the dynamic strategies of interest over long periods of follow-up, we describe how to leverage an additional assumption: no direct effect of monitoring on the outcome of interest. We compare our results with and without the "no direct effect" assumption. We found little differences on survival and AIDS-free survival between strategies where monitoring frequency was decreased at a CD4 threshold of 350 cells/μl compared with 500 cells/μl and where treatment was switched at an HIV-RNA threshold of 1000 copies/ml compared with 200 copies/ml. The "no direct effect" assumption resulted in efficiency improvements for the risk difference estimates ranging from an 7- to 53-fold increase in the effective sample size.

Interferon lambda 3/4 polymorphisms are associated with AIDS-related Kaposi's sarcoma

BACKGROUND

Kaposi's sarcoma, the most common AIDS-related cancer, represents a major public concern in resource-limited countries. Single nucleotide polymorphisms within the Interferon lambda 3/4 region (IFNL3/4) determine the expression, function of IFNL4, and influence the clinical course of an increasing number of viral infections.

OBJECTIVES

To analyze whether IFNL3/4 variants are associated with susceptibility to AIDS-related Kaposi's sarcoma among MSM enrolled in the Swiss HIV Cohort Study (SHCS).

METHODS

The risk of developing Kaposi's sarcoma according to the carriage of IFNL3/4 SNPs rs8099917 and rs12980275 and their haplotypic combinations was assessed by using cumulative incidence curves and Cox regression models, accounting for relevant covariables.

RESULTS

Kaposi's sarcoma was diagnosed in 221 of 2558 MSM Caucasian SHCS participants. Both rs12980275 and rs8099917 were associated with an increased risk of Kaposi's sarcoma (cumulative incidence 15 versus 10%, P = 0.01 and 16 versus 10%, P = 0.009, respectively). Diplotypes predicted to produce the active P70 form (cumulative incidence 16 versus 10%, P = 0.01) but not the less active S70 (cumulative incidence 11 versus 10%, P = 0.7) form of IFNL4 were associated with an increased risk of Kaposi's sarcoma, compared with those predicted not to produce IFNL4. The associations remained significant in a multivariate Cox regression model after adjustment for age at infection, combination antiretroviral therapy, median CD4+ T-cell count nadir and CD4+ slopes (hazard ratio 1.42, 95% confidence interval 1.06-1.89, P = 0.02 for IFLN P70 versus no IFNL4).

CONCLUSION

This study reports for the first time an association between IFNL3/4 polymorphisms and susceptibility to AIDS-related Kaposi's sarcoma.

Fatal Measles Virus Infection After Rituximab-Containing Chemotherapy in a Previously Vaccinated Patient

We report the case of a young patient treated with rituximab-containing chemotherapy who was infected with measles despite previous vaccination. Treatment with vitamin A, ribavirin, and immunoglobulins was started; nevertheless he developed severe pneumonitis and deceased. Broad vaccination coverage is crucial in protecting vulnerable subjects.

Awareness and management of elevated blood pressure among human immunodeficiency virus-infected adults receiving antiretroviral therapy in urban Zambia: a call to action

The prevalence of high blood pressure (HBP) and hypertension (HTN), awareness of the diagnoses, and use of anti-hypertensive drugs were examined among human immunodeficiency virus (HIV)-infected individuals on antiretroviral therapy (ART) in Zambia's capital Lusaka. Within a prospective cohort based at two public sector ART clinics, BP was measured at ART initiation and every 6 months thereafter as a routine clinic procedure. Predictors of HBP (systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg) during one year on ART were analyzed using logistic regression, and the proportion with HTN (2+ episodes of HBP >3 months apart) described. A phone survey was used to understand patient awareness of HBP, use of anti-hypertensive drugs, and history of cardiovascular events (CVE; myocardial infarction or stroke). Among 896 cohort participants, 887 (99.0%) had at least one BP measurement, 98 (10.9%) had HBP, and 57 (6.4%) had HTN. Increasing age (10-year increase in age: adjusted odds ratio [AOR] = 1.50; 95% confidence interval [CI] 1.20-1.93), male sex (AOR = 2.33, 95% CI 1.43-3.80), and overweight/obesity (AOR = 4.07; 95% CI 1.94-8.53) were associated with HBP. Among 66 patients with HBP, 35 (53.0%) reported awareness of the condition, and nine (25.7%) of these reported having had a CVE. Only 14 (21.2%) of those reached reported ever taking an anti-hypertensive drug, and one (1.5%) was currently on treatment. These data suggest that major improvements are needed in the management of HBP among HIV-infected individuals in settings such as Zambia.

Strengthening HIV therapy and care in rural Tanzania affects rates of viral suppression

Objectives

To assess viral suppression rates, to assess prevalence of acquired HIV drug resistance and to characterize the spectrum of HIV-1 drug resistance mutations (HIV-DRM) in HIV-1-infected patients in a rural Tanzanian HIV cohort.

Methods

This was a cross-sectional study nested within the Kilombero and Ulanga Antiretroviral Cohort. Virological failure was defined as HIV-1 RNA ≥50 copies/mL. Risk factors associated with virological failure and with the development of HIV-DRM were assessed using logistic regression.

Results

This study included 304 participants with a median time on ART of 3.5 years (IQR = 1.7-5.3 years); 91% were on an NNRTI-based regimen and 9% were on a boosted PI-based regimen. Viral suppression was observed in 277/304 patients (91%). Of the remaining 27 patients, 21 were successfully genotyped and 17/21 (81%) harboured ≥1 clinically relevant HIV-DRM. Of these, 13/17 (76.5%) had HIV-1 plasma viral loads of >1000 copies/mL. CD4 cell count <200 cells/mm(3) at the time of recruitment was independently associated with a close to 8-fold increased odds of virological failure [adjusted OR (aOR) = 7.71, 95% CI = 2.86-20.78, P  <   0.001] and with a >8-fold increased odds of developing HIV-DRM (aOR = 8.46, 95% CI = 2.48-28.93, P  =   0.001).

Conclusions

High levels of viral suppression can be achieved in rural sub-Saharan Africa when treatment and care programmes are well managed. In the absence of routine HIV sequencing, the WHO-recommended threshold of 1000 viral RNA copies/mL largely discriminates virological failure secondary to HIV-DRM.

Prevalence and Evolution of Renal Impairment in People Living With HIV in Rural Tanzania

Background

We assessed the prevalence, incidence, and predictors of renal impairment among people living with HIV (PLWHIV) in rural Tanzania.

Methods

In a cohort of PLWHIV aged ≥15 years enrolled from January 2013 to June 2016, we assessed the association between renal impairment (estimated glomerural filtration rate < 90 mL/min/1.73 m²) at enrollment and during follow-up with demographic and clinical characteristcis using logistic regression and Cox proportional hazards models.

Results

Of 1093 PLWHIV, 172 (15.7%) had renal impairment at enrollment. Of 921 patients with normal renal function at baseline, 117 (12.7%) developed renal impairment during a median follow-up (interquartile range) of 6.2 (0.4–14.7) months. The incidence of renal impairment was 110 cases per 1000 person-years (95% confidence interval [CI], 92–132). At enrollment, logistic regression identified older age (adjusted odds ratio [aOR], 1.79; 95% CI, 1.52–2.11), hypertension (aOR, 1.84; 95% CI, 1.08–3.15), CD4 count <200 cells/mm³ (aOR, 1.80; 95% CI, 1.23–2.65), and World Health Organization (WHO) stage III/IV (aOR, 3.00; 95% CI, 1.96–4.58) as risk factors for renal impairment. Cox regression model confirmed older age (adjusted hazard ratio [aHR], 1.85; 95% CI, 1.56–2.20) and CD4 count <200 cells/mm³ (aHR, 2.05; 95% CI, 1.36–3.09) to be associated with the development of renal impairment.

Conclusions

Our study found a low prevalence of renal impairment among PLWHIV despite high usage of tenofovir and its association with age, hypertension, low CD4 count, and advanced WHO stage. These important and reassuring safety data stress the significance of noncommunicable disease surveillance in aging HIV populations in sub-Saharan Africa.

Rapid decline of anti-hepatitis C virus (HCV) antibodies following early treatment of incident HCV infections in HIV-infected men who have sex with men

OBJECTIVES

Following clearance of incident hepatitis C virus (HCV) infections, HCV antibody levels may decline, resulting in seroreversion. It is unclear to what extent HCV antibody level trajectories differ between patients with treatment-induced sustained virological response (SVR), those with spontaneous clearance and those with untreated replicating HCV infection. We investigated HCV antibody level dynamics in HIV-infected MSM with different clinical outcomes.

METHODS

We investigated anti-HCV antibody level dynamics following an incident HCV infection in 67 HIV-infected men who have sex with men (MSM) with different clinical outcomes: SVR (n = 33), spontaneous clearance (n = 12), and untreated replicating infection (n = 22). Antibody levels were measured at the time of HCV diagnosis, and at yearly intervals for 3 years thereafter.

RESULTS

At baseline, median HCV antibody levels were similar in the three groups: 13.4, 13.8 and 13.5 sample to cut-off (S/CO) for SVR, spontaneous clearance and untreated infection, respectively. Over 3 years of follow-up, SVR was associated with a more pronounced decrease in anti-HCV levels compared with spontaneous clearance and untreated infection [median decline 71% [interquartile range (IQR: 43-87%), 38% (IQR: 29-60%) and 12% (IQR: 9-22%), respectively; P < 0.001]. Seroreversions occurred in five of 33 (15%) patients with SVR and in one of 12 (8%) with spontaneous clearance. A shorter delay between time of infection and treatment start correlated with higher rates of decline in antibody levels. Seven patients experienced a reinfection.

CONCLUSIONS

Treatment-induced HCV clearance was associated with a more pronounced decline in anti-HCV antibody levels and with higher rates of seroreversion compared with spontaneous clearance or untreated replicating HCV infection among HIV-infected MSM with incident HCV infections. Rapid clearance of HCV RNA following early HCV treatment might impair the development of persistent antibody titres.

Management of MDR-TB in HIV co-infected patients in Eastern Europe: Results from the TB:HIV study

OBJECTIVES

Mortality among HIV patients with tuberculosis (TB) remains high in Eastern Europe (EE), but details of TB and HIV management remain scarce.

METHODS

In this prospective study, we describe the TB treatment regimens of patients with multi-drug resistant (MDR) TB and use of antiretroviral therapy (ART).

RESULTS

A total of 105 HIV-positive patients had MDR-TB (including 33 with extensive drug resistance) and 130 pan-susceptible TB. Adequate initial TB treatment was provided for 8% of patients with MDR-TB compared with 80% of those with pan-susceptible TB. By twelve months, an estimated 57.3% (95%CI 41.5-74.1) of MDR-TB patients had started adequate treatment. While 67% received ART, HIV-RNA suppression was demonstrated in only 23%.

CONCLUSIONS

Our results show that internationally recommended MDR-TB treatment regimens were infrequently used and that ART use and viral suppression was well below the target of 90%, reflecting the challenging patient population and the environment in which health care is provided. Urgent improvement of management of patients with TB/HIV in EE, in particular for those with MDR-TB, is needed and includes widespread access to rapid TB diagnostics, better access to and use of second-line TB drugs, timely ART initiation with viral load monitoring, and integration of TB/HIV care.

European AIDS Clinical Society Second Standard of Care Meeting, Brussels 16-17 November 2016: a summary

The European AIDS Clinical Society (EACS) organized a second meeting on Standard of Care in Europe on November 16-17 th, 2016. The aims of the meeting were to discuss and propose actions on three topics, namely: Adherence to guidelines for treatment initiation, treatment monitoring and outcomes, Retention in care and HIV and tuberculosis co-infection. Several actions need to be implemented in order to further improve quality of care and treatment of HIV in Europe. A common ground for standard of care, based on the EACS Guidelines should be established throughout Europe. EACS plans to interact with policy makers and other stakeholders to insure this common minimal level of standard of care, in particular for initiating of ART, accessibility of drugs and monitoring of ART with viral load. Progress should be made to monitor retention in care, prevent lost to follow and insure return to care. Improving integration of services and accessibility to care play a major role. Integration is also key for optimizing care of HIV-tuberculosis co-infection, as well as diagnosis and prevention of tuberculosis in population at risk. The Standard of Care meeting organized every other year by EACS provides a unique opportunity to monitor progresses and pitfalls in HIV patient care throughout Europe. It is also a forum for advocacy towards policy makers and other stakeholders to constantly improve HIV patient global management, aiming to provide the same level of quality on the whole continent.

Comparison of Kaposi Sarcoma Risk in Human Immunodeficiency Virus-Positive Adults Across 5 Continents: A Multiregional Multicohort Study

BACKGROUND

We compared Kaposi sarcoma (KS) risk in adults who started antiretroviral therapy (ART) across the Asia-Pacific, South Africa, Europe, Latin, and North America.

METHODS

We included cohort data of human immunodeficiency virus (HIV)-positive adults who started ART after 1995 within the framework of 2 large collaborations of observational HIV cohorts. We present incidence rates and adjusted hazard ratios (aHRs).

RESULTS

We included 208140 patients from 57 countries. Over a period of 1066572 person-years, 2046 KS cases were diagnosed. KS incidence rates per 100000 person-years were 52 in the Asia-Pacific and ranged between 180 and 280 in the other regions. KS risk was 5 times higher in South African women (aHR, 4.56; 95% confidence intervals [CI], 2.73-7.62) than in their European counterparts, and 2 times higher in South African men (2.21; 1.34-3.63). In Europe, Latin, and North America KS risk was 6 times higher in men who have sex with men (aHR, 5.95; 95% CI, 5.09-6.96) than in women. Comparing patients with current CD4 cell counts ≥700 cells/µL with those whose counts were <50 cells/µL, the KS risk was halved in South Africa (aHR, 0.53; 95% CI, .17-1.63) but reduced by ≥95% in other regions.

CONCLUSIONS

Despite important ART-related declines in KS incidence, men and women in South Africa and men who have sex with men remain at increased KS risk, likely due to high human herpesvirus 8 coinfection rates. Early ART initiation and maintenance of high CD4 cell counts are essential to further reducing KS incidence worldwide, but additional measures might be needed, especially in Southern Africa.

Assessing the danger of self-sustained HIV epidemics in heterosexuals by population based phylogenetic cluster analysis

Assessing the danger of transition of HIV transmission from a concentrated to a generalized epidemic is of major importance for public health. In this study, we develop a phylogeny-based statistical approach to address this question. As a case study, we use this to investigate the trends and determinants of HIV transmission among Swiss heterosexuals. We extract the corresponding transmission clusters from a phylogenetic tree. To capture the incomplete sampling, the delayed introduction of imported infections to Switzerland, and potential factors associated with basic reproductive number R0, we extend the branching process model to infer transmission parameters. Overall, the R0 is estimated to be 0.44 (95%-confidence interval 0.42—0.46) and it is decreasing by 11% per 10 years (4%—17%). Our findings indicate rather diminishing HIV transmission among Swiss heterosexuals far below the epidemic threshold. Generally, our approach allows to assess the danger of self-sustained epidemics from any viral sequence data.

In epidemiology, the “basic reproductive number” describes how efficiently a disease is transmitted, and represents the average number of new infections that an infected individual causes. If this number is less than one, many people do not infect anybody and hence the transmission chains die out. On the other hand, if the basic reproductive number is larger than one, an infected person infects on average more than one new individual, which leads to the virus or bacteria spreading in a self-sustained way.

Turk et al. have now developed a method to estimate the basic reproductive number using the genetic sequences of the virus or bacteria, and have used it to investigate how efficiently HIV spreads among Swiss heterosexuals. The results show that the basic reproductive number of HIV in this group is far below the critical value of one and that over the last years this number has been decreasing. Furthermore, the basic reproductive number differs for different subtypes of the HIV virus, indicating that the geographical region where the infection was acquired may play a role in transmission. Turk et al. also found that people who are diagnosed later or who often have sex with occasional partners spread the virus more efficiently.

These findings might be helpful for policy makers as they indicate that the risk of self-sustained transmission in this group in Switzerland is small. Furthermore the method allows HIV epidemics to be monitored at high resolution using sequence data, assesses the success of currently implemented preventive measures, and helps to target subgroups who are at higher risk of an infection – for instance, by supporting frequent HIV testing of these people. The method developed by Turk et al. could also prove useful for assessing the danger of other epidemics.

A decade of HIV care in rural Tanzania: Trends in clinical outcomes and impact of clinic optimisation in an open, prospective cohort

Objectives

Our objectives were to describe trends in enrolment and clinical outcomes in the open, prospective Kilombero and Ulanga Antiretroviral Cohort (KIULARCO) in the Morogoro region of southern Tanzania, and identify strengths and areas for improvement in the care of HIV-positive individuals in rural Tanzania.

Methods

We included adults (≥15 years) and children (<15 years) enrolled in the cohort in 2005–2014. The cohort underwent significant changes from autumn 2012 to optimise care. We evaluated mortality and loss to follow-up (LTFU) using competing risks methods, ART usage, opportunistic infections (OI), co-infections and laboratory abnormalities.

Results

Overall, 7010 adults and 680 children were enrolled; enrolment peaked in 2008 but has increased steadily since 2011. Among adults (65% female; median age 37 [interquartile range 31–45] years), the proportion referred from hospital wards quadrupled in 2013–14 versus earlier years. 653 (9%) adults died and 2648 (38%) were LTFU; the five-year cumulative probabilities of death and LTFU were 10.3% and 44.0%, respectively. Among children, 69 (10%) died and 225 (33%) were LTFU. The corresponding five-year probabilities were 12.1% and 39.6%. Adult ART use (regardless of eligibility) increased from 5% in 2005 to 89% in 2014 (similarly among children), with 9% on second-line therapy in 2014 (17% of children). OI diagnoses increased over time; tuberculosis prevalence at enrolment quadrupled from 6% in 2011 to 26% in 2014. The proportion of newly-enrolled participants assessed for laboratory abnormalities peaked at nearly 100% in 2014 (from a minimum of 24%), yet abnormality prevalences remained fairly constant.

Conclusions

In this cohort, ART usage improved dramatically and is approaching targets of 90%. Improved screening led to increases in detection of OIs and laboratory abnormalities, suggesting that a large number of these co-morbidities previously went undetected and untreated. Further work will address the high LTFU rates and implications for mortality estimates, and the management and outcomes of co-morbidities.

First two cases of severe multifocal infections caused by Klebsiella pneumoniae in Switzerland: characterization of an atypical non-K1/K2-serotype strain causing liver abscess and endocarditis

BACKGROUND

We describe the first two multifocal invasive infections due to Klebsiella pneumoniae recently observed in Switzerland.

METHODS

Phenotypic (MIC assays and string test) and molecular analyses (PCR/Sequencing for bla, virulence factor genes and whole genome sequencing for one strain) were performed to characterize the causative K. pneumoniae isolates.

RESULTS

Both K. pneumoniae isolates (Kp1 and Kp2) were pan-susceptible to antibiotics and produced narrow-spectrum SHV β-lactamases. However, only Kp1 was string test positive. Kp1 was of ST380 and caused liver abscess as well as pneumonia and orbital phlegmon in an Eritrean patient. It belonged to the hypervirulent capsular serotype K2 and harboured the classic virulence-associated rmpA and aerobactin genes, fulfilling both the clinical and microbiological definitions for an invasive K. pneumoniae syndrome. Kp2 was of ST1043 and caused both liver abscess and endocarditis in a Swiss patient. Moreover, it did not possess the classic virulence-associated genes. Whole genome sequencing identified less well-known virulence factors in Kp2 that might have contributed to its virulence. Among these there were genes important for intestinal colonization and/or invasion, such as genes involved in adhesion (e.g., fimABCD and mrkABCD), regulation of capsule polysaccharide biosynthesis (e.g., evgS-evgA), as well as iron uptake (iroN), energy conversion, and metabolism.

DISCUSSION

This report confirms the continuous dissemination of hypervirulent K. pneumoniae strains among patients of non-Asian descent in Europe. Moreover, it highlights the genetic background of an atypical hypervirulent K. pneumoniae causing a severe invasive infection despite not possessing the classical virulence characteristics of hypermucoviscous strains.

Cohort profile: The Kilombero and Ulanga Antiretroviral Cohort (KIULARCO) - A prospective HIV cohort in rural Tanzania

BACKGROUND

The Kilombero and Ulanga Antiretroviral Cohort (KIULARCO) is a single-site, open and ongoing prospective cohort of people living with human immunodeficiency virus (PLWHIV) established in 2005 at the Chronic Diseases Clinic of Ifakara (CDCI), within the Saint Francis Referral Hospital (SFRH) in Ifakara, Tanzania. The objectives of KIULARCO are to (i) provide patient and cohort-level information on the outcomes of HIV treatment; (ii) provide cohort-level information on opportunistic infections and comorbidities; (iii) evaluate aspects of human immunodeficiency virus (HIV) care and treatment that have national or international policy relevance; (iv) provide a platform for studies on improving HIV care and treatment in sub-Saharan Africa; and (v) contribute to generating local capacity to deal with the challenges posed by the HIV/AIDS pandemic in this region. Moreover, KIULARCO may serve as a model for other healthcare settings in rural sub-Saharan Africa.

METHODS

Since 2005, all patients diagnosed with HIV at the Saint Francis Referral Hospital are invited to participate in the cohort, including non-pregnant adults, pregnant women, adolescents, children and infants. The information collected includes demographics, baseline and follow-up clinical data, laboratory data, medication history, drug toxicities, diagnoses and outcomes. Real-time data are captured during the patient encounter through an electronic medical record system that allowed transition to a paperless clinic in 2013. In addition, KIULARCO is associated with a biobank of cryopreserved plasma samples and cell pellets collected from all participants before and at different time-points during antiretroviral treatment.

RESULTS

Up to the end of 2016, 12 185 PLWHIV have been seen at the CDCI; 9218 (76%) of whom have been enrolled into KIULARCO and 6965 (76%) of these have received ART from the clinic. Patients on ART attend at least every 3 months, with laboratory monitoring every 6 months. KIULARCO data have been used to generate relevant information regarding ART outcomes, opportunistic infections, non-AIDS comorbidities, prevention of mother-to-child transmission of HIV, paediatric HIV, and mortality and retention in care. Requests for collaborations on analyses can be submitted to the KIULARCO scientific committee.

CONCLUSIONS

KIULARCO provides a framework for improving the quality of care of people living with HIV in sub-Saharan Africa, to generate relevant information to evaluate ART programmes and to build local capacity to deal with HIV/AIDS. The comprehensiveness of the data collected, together with the biobank spanning over ten years has created a unique research platform in rural sub-Saharan Africa.

Impact of early versus deferred antiretroviral therapy on estimated glomerular filtration rate in HIV-positive individuals in the START trial

The impact of early ART initiation (versus deferring) on kidney function has not been studied. START was a randomised comparison of immediate versus deferred ART initiation among HIV-positive persons with CD4⁺ (cells/mm³) counts >500. Serum creatinine and urine dipstick protein were measured at Months 0, 1, 4, 8 and 12, and annually thereafter. The two arms were compared for changes in eGFR (mL/min/1.73 m², calculated by CKD-EPI equation), over time using longitudinal mixed models. Of 4685 START participants, 4629 (2294 in immediate and 2335 deferred arm) were included. Median baseline CD4⁺ and eGFR were 651 and 111.5, respectively. ART was initiated in 2271 participants (99.0%) in the immediate and 1127 (48.3%) in the deferred arm, accounting for >94% and >19% of follow-up time, respectively. Overall, 89% started ART using a tenofovir-based regimen. Over 2.1 years median follow-up, mean eGFR was 0.56 (95% CI 0.003-1.11) higher in the immediate versus deferred arm, which was more prominent after adjustment for current tenofovir or bPI use (1.85, 95% CI 1.21-2.50) and in Black participants (30.1% overall) (3.90, 95% CI 2.84-4.97) versus non-Blacks (1.05, 95% CI 0.33-1.77) (P < 0.001 for interaction). Relative risk for proteinuria in the immediate versus deferred arm was 0.74 (95% CI 0.55-1.00) (P = 0.049). In the short-term, immediate ART initiation was associated with a modestly higher eGFR and lower proteinuria risk versus deferring ART (more pronounced in Black participants). Whether this early benefit translates into a lower risk of CKD requires further follow-up.

Comparison of dynamic monitoring strategies based on CD4 cell counts in virally suppressed, HIV-positive individuals on combination antiretroviral therapy in high-income countries: a prospective, observational study

BACKGROUND

Clinical guidelines vary with respect to the optimal monitoring frequency of HIV-positive individuals. We compared dynamic monitoring strategies based on time-varying CD4 cell counts in virologically suppressed HIV-positive individuals.

METHODS

In this observational study, we used data from prospective studies of HIV-positive individuals in Europe (France, Greece, the Netherlands, Spain, Switzerland, and the UK) and North and South America (Brazil, Canada, and the USA) in The HIV-CAUSAL Collaboration and The Centers for AIDS Research Network of Integrated Clinical Systems. We compared three monitoring strategies that differ in the threshold used to measure CD4 cell count and HIV RNA viral load every 3-6 months (when below the threshold) or every 9-12 months (when above the threshold). The strategies were defined by the threshold CD4 counts of 200 cells per μL, 350 cells per μL, and 500 cells per μL. Using inverse probability weighting to adjust for baseline and time-varying confounders, we estimated hazard ratios (HRs) of death and of AIDS-defining illness or death, risk ratios of virological failure, and mean differences in CD4 cell count.

FINDINGS

47 635 individuals initiated an antiretroviral therapy regimen between Jan 1, 2000, and Jan 9, 2015, and met the eligibility criteria for inclusion in our study. During follow-up, CD4 cell count was measured on average every 4·0 months and viral load every 3·8 months. 464 individuals died (107 in threshold 200 strategy, 157 in threshold 350, and 200 in threshold 500) and 1091 had AIDS-defining illnesses or died (267 in threshold 200 strategy, 365 in threshold 350, and 459 in threshold 500). Compared with threshold 500, the mortality HR was 1·05 (95% CI 0·86-1·29) for threshold 200 and 1·02 (0·91·1·14) for threshold 350. Corresponding estimates for death or AIDS-defining illness were 1·08 (0·95-1·22) for threshold 200 and 1·03 (0·96-1·12) for threshold 350. Compared with threshold 500, the 24 month risk ratios of virological failure (viral load more than 200 copies per mL) were 2·01 (1·17-3·43) for threshold 200 and 1·24 (0·89-1·73) for threshold 350, and 24 month mean CD4 cell count differences were 0·4 (-25·5 to 26·3) cells per μL for threshold 200 and -3·5 (-16·0 to 8·9) cells per μL for threshold 350.

INTERPRETATION

Decreasing monitoring to annually when CD4 count is higher than 200 cells per μL compared with higher than 500 cells per μL does not worsen the short-term clinical and immunological outcomes of virally suppressed HIV-positive individuals. However, more frequent virological monitoring might be necessary to reduce the risk of virological failure. Further follow-up studies are needed to establish the long-term safety of these strategies.

FUNDING

National Institutes of Health.

Mining for pairs: shared clinic visit dates identify steady HIV-positive partnerships

OBJECTIVES

Here we examined the hypothesis that some stable HIV-infected partnerships can be found in cohort studies, as the patients frequently attend the clinic visits together.

METHODS

Using mathematical approximations and shuffling to derive the probabilities of sharing a given number of visits by chance, we identified and validated couples that may represent either transmission pairs or serosorting couples in a stable relationship.

RESULTS

We analysed 434 432 visits for 16 139 Swiss HIV Cohort Study patients from 1990 to 2014. For 89 pairs, the number of shared visits exceeded the number expected. Of these, 33 transmission pairs were confirmed on the basis of three criteria: an extensive phylogenetic tree, a self-reported steady HIV-positive partnership, and risk group affiliation. Notably, 12 of the validated transmission pairs (36%; 12 of 33) were of a mixed ethnicity with a large median age gap [17.5 years; interquartile range (IQR) 11.8-22 years] and these patients harboured HIV-1 of predominantly non-B subtypes, suggesting imported infections.

CONCLUSIONS

In the context of the surge in research interest in HIV transmission pairs, this simple method widens the horizons of research on within-pair quasi-species exchange, transmitted drug resistance and viral recombination at the biological level and targeted prevention at the public health level.

Ethnicity predicts viral rebound after travel to the tropics in HIV-infected travelers to the tropics in the Swiss HIV Cohort Study

OBJECTIVES

The number of HIV-infected individuals from developed countries travelling to tropical and subtropical areas has increased as a result of the clinical and survival benefits of combination antiretroviral therapy. The aim of our study was to describe the traveler population in the SHCS and to determine the frequency of viral rebound in virologically suppressed individuals after a travel episode to the tropics compared to non-travelers.

METHODS

Swiss HIV Cohort Study participants with at least one follow-up visit between 1 January 1989 and 28 February 2015 were eligible for inclusion in the study. The primary outcome was the occurrence of viral rebound (viral load > 200 HIV-1 RNA copies/mL) after a travel episode compared with a nontravel episode in previously suppressed individuals (≤ 200 copies/mL). All virologically suppressed patients contributed multiple travel or nontravel episodes to the analysis. Logistic regression was performed including factors associated with viral rebound.

RESULTS

We included 16 635 patients in the study, of whom 6084 (36.5%) had ever travelled to the tropics. Travel frequency increased over time, with travellers showing better HIV parameters than nontravellers [less advanced Centers for Disease Control and Prevention (CDC) stage and higher CD4 count nadir]. Viral rebound was seen in 477 (3.9%) of 12 265 travel episodes and in 5121 (4.5%) of 114 884 nontravel episodes [unadjusted odds ratio (OR) 0.87; 95% confidence interval (CI) 0.78-0.97]. Among these 477 post-travel viral rebounds, 115 had a resistance test performed and 51 (44%) of these showed new resistance mutations. Compared with European and North American patients, the odds for viral rebound were significantly lower in Southeast Asian (OR 0.67; 95% CI 0.51-0.88) and higher in sub-Saharan African (SSA) patients (OR 1.41; 95% CI 1.22-1.62). Travel further increased the odds of viral rebound in SSA patients (OR 2.00; 95% CI 1.53-2.61).

CONCLUSIONS

Region of origin is the main risk factor for viral rebound rather than travel per se. Pre-travel adherence counselling should focus on patients of SSA origin.