Regarding the diagnosis of acute poststreptococcal glomerulonephritis (APSGN), which ONE of the following statements is TRUE?
Answer: D: Group A β-haemolytic streptococcal infections are common in children and can lead to the postinfectious complication of acute glomerulonephritis. ASPGN is characterised by the sudden onset of gross haematuria, oedema, hypertension and renal insufficiency. Peripheral oedema typically results from salt and water retention and is common; nephrotic syndrome develops in a minority (<5%) of childhood cases.
Confirmation of the diagnosis requires clear evidence of a prior streptococcal infection. Although a positive throat culture may support the diagnosis it may simply represent the carrier state and is not necessarily the cause of glomerulonephritis. An ASO titer of 250 U or higher is highly suggestive of recent streptococcal infection. However, a rise in the titer of the antibody, measured at an interval of 2–3 weeks, is more meaningful than a single measurement. Importantly, the antistreptolysin O titer is commonly elevated after a pharyngeal infection but rarely increases after streptococcal skin infections. Anti–DNAse B and AHase titers are more often positive following skin infections. The serum C3 level is significantly reduced in >90% of patients in the acute phase and returns to normal 6–8 weeks after onset. C4 is most often normal in APSGN, or only mildly depressed.
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Which ONE of the following features is NOT consistent with nephrotic syndrome?
Answer: C: Nephrotic syndrome can be primary (involving only the kidneys) or secondary (multisystem). Primary nephrotic syndrome occurs more commonly in children younger than 5 years, whereas secondary nephrotic syndrome occurs more often in older children. Around 90% of affected children have the primary disease, with the majority having minimal change nephrotic syndrome. The diagnostic criteria for nephrotic syndrome are generalised oedema, hypoproteinemia with a disproportionately low albumin level, proteinuria (3+ or 4+ on the dipstick reading) and hyperlipidaemia. Microscopic haematuria also may be present.
Serum complements, antibodies and coagulation factors are lost as protein in the urine, making these children susceptible to severe infection and thromboembolic events. Steroid therapy further increases the infection risk. Hyperlipidaemia may lead to hyperviscosity and further increase the thrombotic risk.
Which ONE of the following statements is TRUE regarding haematuria?
Answer: D: The causes of haematuria can be divided into haematologic, renal and postrenal causes. Renal causes may be further classified as glomerular or nonglomerular. Gross haematuria more often indicates a lower tract cause, whereas microscopic haematuria tends to occur with kidney disease. The presence of red cell casts and proteinuria suggest a glomerular source.
Haematuria associated with pain during urination is often due to a UTI, whereas painless haematuria is more often due to neoplastic, hyperplastic and vascular causes. Haematuria in patients on oral anticoagulants should not be attributed to the anticoagulant alone because the incidence of underlying disease is as high as 80%. Patients younger than 40 years of age with a first episode of asymptomatic microscopic haematuria should have a repeat urine analysis ideally within 2 weeks. If haematuria is persistent, further urological evaluation is warranted. Most patients older than 40 years should undergo a thorough evaluation after even a single episode of haematuria.
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Which ONE of the following is INCORRECT regarding prostatitis?
Answer: B: The most common pathogens associated with acute bacterial prostatitis are gram-negative bacilli (uropathogens), such as E. coli and Proteus spp. Additionally, ascending urethral infection with Neisseria gonorrhoeae and Chlamydia trachomatis may occur following sexual intercourse, especially in sexually active men younger than 35 years and older men who engage in high-risk sexual behaviours.
The diagnosis of acute bacterial prostatitis is usually based on symptoms alone: urinary symptoms (irritative or obstructive), pain in the suprapubic or perineal region, or in the external genitalia, as well as systemic symptoms of fever, chills or malaise. A gentle digital examination will reveal a hot, swollen, tender prostate. Prostatic massage with sampling of prostatic fluid for culture is not recommended with acute bacterial prostatitis because it can precipitate bacteraemia. A simple midstream urine specimen should rather be obtained for microscopy and culture. The presence of >10 WBC/hpf suggests a positive diagnosis.
Chronic prostatitis can be due to bacterial or non-bacterial causes. Chronic bacterial prostatitis usually occurs in adults who have a history of recurrent urinary tract infection. Symptoms include recurring episodes of pain or discomfort in the perineum, groin, lower back, or scrotum and voiding dysfunction. Prostatic examination is not usually helpful because findings are variable. To further classify chronic prostatitis, cultures of urine before and after a prostatic massage are necessary to rule out infection. This is obtained by collecting midstream urine followed by collecting the first 10 mL of urine after a vigorous prostate massage.
Regarding the aetiology of urinary tract infections (UTIs), which ONE of the following is TRUE?
Answer: D: Reinfection (within 1–6 months after treatment) is usually by different enteric organism or different serotype of same organism. Relapse of UTI is recurrence of symptoms within 1 month (caused by the same organism) and represents treatment failure. The most common urinary tract pathogen is E. coli. In acute uncomplicated cystitis E. coli is the responsible organism in 70–90% of cases. Although E.coli are isolated in 20–50% of cases of complicated UTIs, other gram-negative bacteria (e.g. Proteus, Klebsiella), enterococci and Streptococcus agalactiae (group B streptococcus) are more common in this group.
Chlamydia trachomatis is common in dysuria-pyuria syndrome (culture negative pyuria) in which sterile or low-colony count culture results are obtained. Pseudomonas species have a low virulence for the urinary tract and its presence suggests that normal host defenses have been altered. The most common reasons for this are incomplete emptying of the urinary tract due to obstruction, high-grade vesicoureteric reflux or voiding dysfunction.