Impact of human coronavirus infections on paediatric patients at a tertiary paediatric hospital: a retrospective study of the prepandemic era

BACKGROUND

Human coronaviruses (HCoVs) are important respiratory pathogens in humans and animals. Most HCoVs are emerging pathogens, with five known human pathogens identified in the last two decades.

AIM

To examine the clinical course of HCoV infection in children to improve understanding of severity and outcomes.

METHODS

A retrospective review was undertaken of all encounters of children with known HCoV infection at a tertiary paediatric hospital from January 2015 to January 2018. Electronic medical records were reviewed for demographic data, HCoV type, viral co-pathogens, time to testing, need for hospitalization, requirement for higher-level care (HLC) including intensive care unit management and requirement for oxygen support, radiographic findings suggestive of lower respiratory tract (LRT) disease, and length of stay (LOS).

FINDINGS

In total, 450 encounters for 430 different patients were identified, with the majority (85%) being inpatient. OC43 was the most common HCoV. Younger patients (age <5 years) had higher probability of hospitalization [adjusted odds ratio (aOR) 2.2, 95% confidence interval (CI) 1.2-4.1], requirement for HLC (aOR 1.8, 95% CI 1.0-3.1) and presence of LRT findings on chest radiographs (aOR 1.7, 95% CI 1.01-2.9). Clinical outcomes did not differ between HCoV types, except LOS which was longer for 229E. Fifty-two (11%) encounters were detected after 3 days of hospitalization (median 25.5 days), suggesting possible nosocomial infection.

CONCLUSION

HCoVs are important respiratory pathogens in the paediatric population, especially among patients aged <5 years who are at increased risk for severe disease. The role of HCoVs as hospital-acquired pathogens may be underappreciated.

Metallosis following implantation of magnetically controlled growing rods in the treatment of scoliosis: a case series

AIMS

We present a case series of five patients who had revision surgery following magnetic controlled growing rods (MGCR) for early onset scoliosis. Metallosis was found during revision in four out of five patients and we postulated a mechanism for rod failure based on retrieval analysis.

PATIENTS AND METHODS

Retrieval analysis was performed on the seven explanted rods. The mean duration of MCGR from implantation to revision was 35 months (17 to 46). The mean age at revision was 12 years (7 to 15; four boys, one girl).

RESULTS

A total of six out of seven rods had tissue metallosis and pseudo-capsule surrounding the actuator. A total of four out of seven rods were pistoning. There were two rods which were broken. All rods had abrasive circumferential markings. A significant amount of metal debris was found when the actuators were carefully cut open. Analytical electron microscopy demonstrated metal fragments of predominantly titanium with a mean particle size of 3.36 microns (1.31 to 6.61).

CONCLUSION

This study highlights concerns with tissue metallosis in MCGR. We recommend careful follow-up of patients who have received this implant. Cite this article: Bone Joint J 2016;98-B:1662-7.

Helicase-primase as a target of new therapies for herpes simplex virus infections

The seminal discovery of acyclovir 40 years ago heralded the modern era of truly selective antiviral therapies and this drug remains the therapy of choice for herpes simplex virus infections. Yet by modern standards, its antiviral activity is modest and new drugs against novel molecular targets such as the helicase-primase have the potential to improve clinical outcome, particularly in high-risk patients. A brief synopsis of current therapies for these infections and clinical need is provided to help provide an initial perspective. The function of the helicase-primase complex is then summarized and the development of new inhibitors of the helicase-primase complex, such as pritelivir and amenamevir, is discussed. We review their mechanism of action, propensity for drug resistance, and pharmacokinetic characteristics and discuss their potential to advance current therapeutic options. Strategies that include combinations of these inhibitors with acyclovir are also considered, as they will likely maximize clinical efficacy.

Risk of vascular access complications with frequent hemodialysis

Frequent hemodialysis requires using the vascular access more often than with conventional hemodialysis, but whether this increases the risk for access-related complications is unknown. In two separate trials, we randomly assigned 245 patients to receive in-center daily hemodialysis (6 days per week) or conventional hemodialysis (3 days per week) and 87 patients to receive home nocturnal hemodialysis (6 nights per week) or conventional hemodialysis, for 12 months. The primary vascular access outcome was time to first access event (repair, loss, or access-related hospitalization). Secondary outcomes were time to all repairs and time to all losses. In the Daily Trial, 77 (31%) of 245 patients had a primary outcome event: 33 repairs and 15 losses in the daily group and 17 repairs, 11 losses, and 1 hospitalization in the conventional group. Overall, the risk for a first access event was 76% higher with daily hemodialysis than with conventional hemodialysis (hazard ratio [HR], 1.76; 95% confidence interval [CI], 1.11-2.79; P=0.017); among the 198 patients with an arteriovenous (AV) access at randomization, the risk was 90% higher with daily hemodialysis (HR, 1.90; 95% CI, 1.11-3.25; P=0.02). Daily hemodialysis patients had significantly more total AV access repairs than conventional hemodialysis patients (P=0.011), with 55% of all repairs involving thrombectomy or surgical revision. Losses of AV access did not differ between groups (P=0.58). We observed similar trends in the Nocturnal Trial, although the results were not statistically significant. In conclusion, frequent hemodialysis increases the risk of vascular access complications. The nature of the AV access repairs suggests that this risk likely results from increased hemodialysis frequency rather than heightened surveillance.

The genetic basis of human cytomegalovirus resistance and current trends in antiviral resistance analysis

Infections due to resistant human cytomegalovirus (CMV) are an emerging problem, particularly in immunocompromised hosts. When managing such patients, clinicians should be aware of the possibility of developing CMV antiviral resistance, especially while on prolonged therapy or if severe immunosuppression is present. CMV resistance to current antiviral agents is mediated by alterations in either the UL97 kinase or DNA polymerase, encoded by the UL97 and UL54 genes, respectively. UL97 mutations are capable of conferring resistance to ganciclovir, while UL54 mutations can impart resistance to ganciclovir, cidofovir, and foscarnet. If treatment failure is suspected to be due to antiviral resistance, CMV resistance analysis should be obtained. Phenotypic resistance assays performed on clinical isolates measure antiviral susceptibilities directly, but are laborious and time-consuming. Therefore, genotypic resistance analysis has become the more common means of diagnosing CMV resistance. Mutations in UL97 or UL54 may be clinically associated with resistance, but their effect on antiviral susceptibility must be confirmed by marker transfer techniques such as recombinant phenotyping.

Effects of frequent hemodialysis on measures of CKD mineral and bone disorder

More frequent hemodialysis sessions and longer session lengths may offer improved phosphorus control. We analyzed data from the Frequent Hemodialysis Network Daily and Nocturnal Trials to examine the effects of treatment assignment on predialysis serum phosphorus and on prescribed dose of phosphorus binder, expressed relative to calcium carbonate on a weight basis. In the Daily Trial, with prescribed session lengths of 1.5-2.75 hours six times per week, assignment to frequent hemodialysis associated with both a 0.46 mg/dl decrease (95% confidence interval [95% CI], 0.13-0.78 mg/dl) in mean serum phosphorus and a 1.35 g/d reduction (95% CI, 0.20-2.50 g/d) in equivalent phosphorus binder dose at month 12 compared with assignment to conventional hemodialysis. In the Nocturnal Trial, with prescribed session lengths of 6-8 hours six times per week, assignment to frequent hemodialysis associated with a 1.24 mg/dl decrease (95% CI, 0.68-1.79 mg/dl) in mean serum phosphorus compared with assignment to conventional hemodialysis. Among patients assigned to the group receiving six sessions per week, 73% did not require phosphorus binders at month 12 compared with only 8% of patients assigned to sessions three times per week (P<0.001). At month 12, 42% of patients on nocturnal hemodialysis required the addition of phosphorus into the dialysate to prevent hypophosphatemia. Frequent hemodialysis did not have major effects on calcium or parathyroid hormone concentrations in either trial. In conclusion, frequent hemodialysis facilitates control of hyperphosphatemia and extended session lengths could allow more liberal diets and freedom from phosphorus binders.

Treatment of herpes simplex virus infections in pediatric patients: current status and future needs

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) are members of the Herpesviridae family and are characterized by their ability to establish latency after primary infection and subsequently reactivate. HSV infections in the neonatal and pediatric populations range from uncomplicated mucocutaneous diseases to severe, life-threatening infections involving the central nervous system (CNS). The antiviral agent acyclovir has significantly improved treatment outcomes of HSV infections, including the frequency of mucocutaneous recurrences and mortality associated with CNS and disseminated infections.

Tibiofibular synostosis in a professional football player

We present an unusual cause of anterior tibial pain in a 24-year-old professional international football player who was found to have a synostosis of the middle-third of the diaphysis of the tibia and fibula.

This is a rarely described phenomenon. Conservative treatment is the recommended treatment of choice, but this failed in our patient. Resection produced resolution of symptoms; he remained symptom-free three years later.

'Fat fracture'--a physical sign mimicking tendon rupture

The imaging techniques available to aid the diagnosis of ruptures of tendo Achillis, the rotator cuff and the tendon of tibialis posterior in rheumatoid patients are well described. However, ruptures of tendon or muscle at other sites are uncommon and may be overlooked. Diagnosis is often made by localised tenderness, swelling and a lack of active movement associated with a palpable defect. Clinical examination may be inconclusive and can be aided by imaging studies. We report two cases in which ruptures of a tendon were suspected, and ultrasound imaging demonstrated the palpable defect to be a cleavage plane in the subcutaneous fat--a 'fat fracture'.

Microangiopathic hemolytic anemia as a complication of diabetes mellitus

A mature-onset diabetic patient who developed microangiopathic hemolytic anemia (MHA) is presented. Although numerous causes of hemolysis are reported in the literature, MHA is a rare complication of diabetes. The proposed mechanism of hemolytic anemia is thought to be related to the abnormal formation of cell membranes in the diabetic environment. The ratio of cholesterol to phospholipid in the core of the membrane is altered in diabetics; as a result, the red blood cell wall becomes rigid and nondeformable. The abnormal cells becomes disrupted as they circulate through the microangiopathic blood vessels. The mechanism of action of the antiplatelet agents is to enhance cell membrane compliance. With improved cell-wall compliance, one can expect a reduction in hemolysis, as occurred in our patient. The literature on diabetes mellitus-related microangiopathic hemolytic anemia is reviewed.

Acute massive gentamicin intoxication in a patient with end-stage renal disease

A 65-year-old man with end-stage renal disease on continuous ambulatory peritoneal dialysis accidentally received an acute massive overdose of gentamicin as a treatment of peritonitis. The patient developed acute vestibular dysfunction and hearing loss following the overdose. His serum gentamicin had reached the extremely toxic level of 220 microg/mL. To remove the gentamicin, the patient received hemodialysis and hemoperfusion immediately. This was followed by two more courses of hemodialysis during the following 2 days. The gentamicin level was brought down to 10 microg/mL after the third hemodialysis. Moderate and persistent high-frequency hearing loss was documented with serial audiograms. The patient made a gradual but incomplete recovery from the vestibular dysfunction. The complications of gentamicin toxicity and its management are discussed with respect to our patient.

Acute renal failure in membranous glomerulonephropathy: a result of superimposed crescentic glomerulonephritis

A patient who presented with acute renal failure and anasarca secondary to crescentic glomerulonephritis superimposed on existing membranous glomerulonephropathy of 15 years' duration is described. The patient responded to an initial course of prednisone but failed to respond to a second course after relapse. The differential diagnosis of acute renal failure in the setting of nephrotic syndrome is discussed. Eighteen cases of crescentic glomerulonephritis superimposed on membranous glomerulonephropathy are reviewed. The clinical setting is heterogeneous with variable presentation and outcome. It appears that patients without antiglomerular basement membrane antibodies have a better prognosis than those who have antibodies. Patients with membranous glomerulonephropathy who develop unexplained acute renal failure should undergo early renal biopsy in order to rule out unexpected pathologic complications.

Partial recovery of renal function in black patients with apparent end-stage renal failure due to primary malignant hypertension

We report the largest series in which 12 out of 54 patients with primary malignant hypertension requiring dialysis recovered sufficient renal function to allow withdrawal of dialysis. The patients were divided into recovery (RC; n = 12) and non-recovery (N-RC; n = 42) groups. The two groups were compared for variables which might predict RC. They were also assessed for survival. Nine of the RC and 6 of the N-RC patients presented with acute oliguria (p = 0.01). The initial mean arterial pressure was significantly higher in the RC than the N-RC group (178 +/- 17 vs. 160 +/- 27 mm Hg; p = 0.03). Although not statistically significant, more females recovered (8 of 12 vs. 16 of 42; p < 0.1). More patients presenting with serum creatinine concentrations < 1,000 mumol/l (11 mg/dl) recovered (p = 0.09), while the presence of microangiopathic-haemolytic anaemia occurred more frequently in the RC (7 of 10) than in the N-RC (15 of 35) group (p = 0.16)> Age, kidney size, and the presence of hypertensive retinopathy did not distinguish between the two groups. RC patients had a greater long-term survival (Mantel-Cox chi2 = 4.48; p = 0.03). The renal function RC may be related to the type of dialysis provided (intermittent peritoneal dialysis) and to the use of modern potent peripheral vasodilator antihypertensive agents. Potential renal function RC should always be considered in patients being dialyzed for primary malignant hypertension.

Malignant hypertension and its renal complications in black South Africans

Malignant hypertension is an important cause of morbidity and mortality among urban black South Africans. Hypertension accounts for 15.9% of all patients and for 34.6% of blacks receiving treatment for end-stage renal failure. Malignant hypertension is more commonly diagnosed than benign hypertension and two-thirds of patients present in the age group 30 - 49 years. Together they are the most common preventable cause of end-stage renal failure in this country. Acute partially reversible renal failure occurs in 20% of patients with malignant hypertension who require dialysis. This is an important subgroup, who may be recognised by their younger age, female preponderance and fulminant presentation. Short-term peritoneal dialysis and effective control of blood pressure will result in satisfactory return of renal function. However, only adequate country-wide control of hypertension will prevent these costly renal complications.

Retinal complications in the acquired immunodeficiency syndrome. A case report

Increasing numbers of patients with the acquired immunodeficiency syndrome (AIDS) are being reported. In the US literature the eye complications have been well documented but because so few cases of AIDS have been reported in South Africa, the retinal complications are largely unknown to those treating these patients. The retinal complications are due to cytomegalovirus (CMV) retinitis. The patient described here developed the typical signs in both eyes. It is essential to examine the fundi of AIDS patients regularly. The presence of cotton-wool spots always precedes CMV retinitis, which leads to blindness; it is also of prognostic significance since all reported patients with CMV retinitis have died.

Phencyclidine: tissue distribution in the rat

This study was performed to provide knowledge of the tissue distribution of phencyclidine and has demonstrated the lipophilic nature of the drug. The distribution of phencyclidine in blood, brain, and adipose tissue of rats has been determined at various time intervals during a 48-hr period. The affinity of phencyclidine for adipose tissue and the demonstration of the presence of this drug in brain tissue long after it is no longer detectable in blood provides some correlation between the tissue distribution of phencyclidine and its clinical manifestations occuring 24-48 hr after administration.

Phencyclidine--states of acute intoxication and fatalities

Phencyclidine is now one of the most frequently used main ingredients of "street drug" preparations. Its effects are highly dose dependent and three varieties of acute intoxication have been seen clinically associated with different dosages and routes of administration. Most persons using phencyclidine smoke it sprinkled on parsley in low doses. The presence of horizontal and vertical nystagmus associated with hypertension in a patient who is agitated or comatose are diagnostic of a phencyclidine intoxicated state. Sensory isolation and intravenous administration of diazepam in the event of seizure activity have proved effective in the treatment of acute intoxicated states. Phencyclidine has pronounced behavioral toxicity and several deaths due to this agent have now been documented. It is unknown whether seizure activity or respiratory depression is the primary cause of death in pharmacological overdoses.