Circumcision for the prevention of urinary tract infection in boys: a systematic review of randomised trials and observational studies

[Urinary tract infections in children]

Urinary tract infection (UTI) is relatively frequent in children. The younger the child is, the more symptoms are atypical. UTI is often associated with functional or malformative uropathy, such as vesico-ureteral reflux or obstruction. Appropriate imaging studies should be carried out in every infected child. The prognosis of uncomplicated UTI is very good, but is less favorable when the UTI is associated with urological abnormalities. Development of pyelonephritic scars can lead to kidney scarring, for which the occurrence of intrarenal reflux is probably responsible . Short-term treatment is recommended for uncomplicated UTI. Uncomplicated UTI with frequent relapses requires prophylactic chemotherapy; this treatment should also be considered when UTI is associated with vesico-ureteral reflux. Surgery is indicated in the presence of major urological malformations. Whether medical or surgical, the treatment of UTI should be followed by urine cultures whenever the child presents with fever. The antibiotic treatment of acute pyelonephritis must be started immediately, preferentially by intravenous route. A switch to oral treatment can be made after obtaining the results of the antibiogram. UTI represents a major risk in neonates; it should preferably be managed in specialized centers.

Risk factors for urinary tract infection in children: a population-based study of 2856 children

AIM

To identify risk factors for urinary tract infection (UTI) in children to inform the development of preventative strategies.

METHOD

A validated questionnaire covering demographic factors, perinatal, developmental, bowel and urinary history was sent to a cross-sectional sample of parents of elementary school children randomly selected from the first 4 years of school. UTI was ascertained by parental report, verified by cross-referencing with microbiological reports for all positive cases and 50 randomly selected negative cases.

RESULTS

Parents of 2856 children (mean age 7.3 years, range 4.8-12.8 years) responded. A total of 3.6% of children had a bacteriologically verified UTI, compared with 12.6% by parental report alone. Multivariate polychotomous logistic regression showed that a history of structural kidney abnormalities (odds ratio (OR) 15.7, 95% confidence interval 8.1-30.4), daytime incontinence (OR 2.6, 1.6-4.5), female gender (OR 2.4, 1.5-3.8), and encopresis (OR 1.9, 1.1-3.4) were independently associated with UTI. Daytime incontinence increased risk more in boys (8.3% vs. 1.2%) than girls (8.1% vs. 4.6%), and kidney problems increased risk in older compared with younger children (29% vs. 2% in > or =8 year olds, 0% vs. 4% in 4-6 year olds).

CONCLUSIONS

Parents over-report UTI by about threefold. Effective treatment of daytime urinary incontinence and encopresis may prevent UTI in children, especially boys.

The risk factors of recurrent urinary tract infection in infants with normal urinary systems

Urinary tract infection (UTI) frequently recurs and increases the risk of renal scarring even in infants with normal urinary tracts. Our study was aimed to find preventive measures for recurrent UTI in these infants. One-hundred ninety infants, who were diagnosed with their first febrile UTI and were proven to have normal urinary systems, were enrolled. We investigated the incidence of recurrent UTI during the following year and the following risk factors: gender, young age, phimosis, vaginal reflux, and acute pyelonephritis (APN) diagnosed by 99m-technetium dimercaptosuccinic acid ((99m)Tc-DMSA)(+) scintigraphy. The incidence of recurrent UTI was 21.1%. The difference in recurrence rate according to gender was not significant. The recurrence rate in infants less than 6 months of age was 25.8%, which was significantly higher than the 7.7% in older infants (P = 0.045). In male infants with persistent non-retractile prepuces, recurrent UTI developed in 34.0%, which was significantly higher than the 17.6% in male infants with retractile prepuces (P = 0.022). The presence of APN in male infants increased the likelihood of recurrent UTI when analyzed by multivariate logistic regression [odds ratio 4.6, 95% confidence interval (95% CI) 1.6-13.0, P = 0.003]. The presence of vaginal reflux and APN in female infants gave no significant difference to the incidence of recurrent UTI. In infants with normal urinary systems, age less than 6 months, non-retractile prepuces and APN in male infants, were the most important risk factors for recurrent UTIs. It is suggested that non-retractile prepuces should be adequately treated to become retractile in young male infants with APN.

What is the effect of circumcision on risk of urinary tract infection in boys with posterior urethral valves?

PURPOSE

Boys with posterior urethral valves (PUV) have increased risks of urinary tract infection (UTI) voiding dysfunction and ongoing renal damage. Circumcision has been shown epidemiologically to reduce UTIs, but no trial has yet confirmed this in PUV. Circumcision is not routinely performed in boys with PUV in our unit, but one quarter of our patients are circumcised for religious reasons. It may be hypothesized that circumcision reduces the risk of subsequent urinary tract infection in boys with PUV. This study aims to test this hypothesis by comparing the risk of UTI, and subsequent renal outcome, in PUV in uncircumcised boys with those who were circumcised.

METHODS

A retrospective cross-sectional case note review of boys with PUV was performed, and the following were documented: age at presentation, method of diagnosis, method of treatment, initial renal status, and timing of treatment; use and timing of urinary tract diversion; timing of circumcision; and UTIs-date, organism, and treatment.

RESULTS

Seventy-eight patients were identified, mean age 6.7 years (range, 1-18). These boys experienced 78 UTIs in the uncircumcised state. Subsequently, 27 were circumcised, experiencing 8 UTIs. Eighteen boys were diverted. The incidence of UTI was reduced from 0.50 +/- 0.14 (mean +/- SEM) UTIs annually uncircumcised to 0.09 +/- 0.02 (mean +/- SEM) circumcised (P < .01, Student's t test).

CONCLUSION

In PUV, circumcision reduces the incidence of UTI by 83%, every circumcision prevents 1 UTI on average. Early circumcision in all PUV is beneficial, but a larger randomised control trial should be considered to confirm this.

Determinants and policy implications of male circumcision in the United States

OBJECTIVE

We sought to determine whether lack of state Medicaid coverage for infant male circumcision correlates with lower circumcision rates.

METHODS

We used data from the Nationwide Inpatient Sample on 417 282 male newborns to calculate hospital-level circumcision rates. We used weighted multiple regression to correlate hospital circumcision rates with hospital-level predictors and state Medicaid coverage of circumcision.

RESULTS

The mean neonatal male circumcision rate was 55.9%. When we controlled for other factors, hospitals in states in which Medicaid covers routine male circumcision had circumcision rates that were 24 percentage points higher than did hospitals in states without such coverage (P<.001). Hospitals serving greater proportions of Hispanic patients had lower circumcision rates; this was not true of hospitals serving more African Americans. Medicaid coverage had a smaller effect on circumcision rates when a hospital had a greater percentage of Hispanic births.

CONCLUSIONS

Lack of Medicaid coverage for neonatal male circumcision correlated with lower rates of circumcision. Because uncircumcised males face greater risk of HIV and other sexually transmitted infections, lack of Medicaid coverage for circumcision may translate into future health disparities for children born to poor families covered by Medicaid.

Antibiotic prophylaxis for childhood urinary tract infection: a national survey

AIMS

To describe attitudes of paediatricians and paediatric nephrologists regarding antibiotic prophylaxis for urinary tract infection (UTI) and determine the factors associated with its use.

METHOD

A self-administered questionnaire was mailed to Canadian paediatricians (1136) and paediatric nephrologists (42).

RESULTS

The response rate was 58.1% (684 physicians); 436 who had made a decision about antibiotic prophylaxis for childhood UTI in the previous year were included in the analysis. Of these, 407 (93.3%) were certified in paediatrics and 29 (6.7%) were paediatric nephrologists. Most respondents prescribed prophylaxis for children with grade III-V vesicoureteral reflux (VUR) (96.5%-98%); 69.8 and 92.8% prescribed it for children with grades I and II VUR, respectively. Factors significantly associated with use of prophylaxis for children with grade I VUR were frequency of decision-making about prophylaxis, city size and province. Fifteen percent of physicians felt that their practice regarding antibiotic prophylaxis for children with VUR was evidence based. A hundred one respondents (24.3%) prescribed prophylaxis for infants with a first febrile UTI in the absence of VUR. Nineteen percent felt that their practice regarding antibiotic prophylaxis for these infants was evidence based. Prescription of prophylaxis for children >12 months with recurrent UTI in the absence of VUR was influenced by frequency of pyelonephritis (88.5% of respondents) and presence of voiding dysfunction (53.8%). Nine percent of physicians felt that their practice for these children was evidence based.

CONCLUSION

Opinions of Canadian paediatricians and paediatric nephrologists regarding antibiotic prophylaxis for UTI in children vary widely, probably because of the paucity of solid evidence about prophylaxis.

The incidence of urinary tract infections in febrile children during a two-year period in Tehran, Iran

Of 433 febrile children examined in the paediatric clinics of two university hospitals in Tehran, Iran, 39 (9%) children (27 girls and 12 boys) were diagnosed as having urinary tract infection in which Escherichia coli was the most frequently detected pathogen (84.6%). According to the voiding cystourethrogram, nine (75%) boys and 17 (63%) girls had urinary tract abnormalities. This result is slightly higher than seen in other reports from developing countries.

Adult male circumcision: effects on sexual function and sexual satisfaction in Kisumu, Kenya

INTRODUCTION

Male circumcision is being promoted for HIV prevention in high-risk heterosexual populations. However, there is a concern that circumcision may impair sexual function.

AIM

To assess adult male circumcision's effect on men's sexual function and pleasure.

METHODS

Participants in a controlled trial of circumcision to reduce HIV incidence in Kisumu, Kenya were uncircumcised, HIV negative, sexually active men, aged 18-24 years, with a hemoglobin >or=9.0 mmol/L. Exclusion criteria included foreskin covering less than half the glans, a condition that might unduly increase surgical risks, or a medical indication for circumcision. Participants were randomized 1:1 to either immediate circumcision or delayed circumcision after 2 years (control group). Detailed evaluations occurred at 1, 3, 6, 12, 18, and 24 months.

MAIN OUTCOME MEASURES

(i) Sexual function between circumcised and uncircumcised men; and (ii) sexual satisfaction and pleasure over time following circumcision.

RESULTS

Between February 2002 and September 2005, 2,784 participants were randomized, including the 100 excluded from this analysis because they crossed over, were not circumcised within 30 days of randomization, did not complete baseline interviews, or were outside the age range. For the circumcision and control groups, respectively, rates of any reported sexual dysfunction decreased from 23.6% and 25.9% at baseline to 6.2% and 5.8% at month 24. Changes over time were not associated with circumcision status. Compared to before they were circumcised, 64.0% of circumcised men reported their penis was "much more sensitive," and 54.5% rated their ease of reaching orgasm as "much more" at month 24.

CONCLUSIONS

Adult male circumcision was not associated with sexual dysfunction. Circumcised men reported increased penile sensitivity and enhanced ease of reaching orgasm. These data indicate that integration of male circumcision into programs to reduce HIV risk is unlikely to adversely effect male sexual function.

Strengths and pitfalls of meta-analysis reports in vesicoureteral reflux

There are many ongoing controversies surrounding vesicoureteral reflux (VUR). These include variable aspects of this common congenital anomaly. Lack of evidence-based recommendations has prolonged the debate. Systematic reviews (SRs) and meta-analysis (MA) are considered high-level evidence. The purpose of this review article is to summarize and critically appraise the available SR/MA pertaining to VUR. We also discuss the strength and pitfalls of SR/MA in general. A thorough literature search identified 9 SRs/MAs relevant to VUR. Both authors critically reviewed these articles for contents and methodological issues. There are many concerns about the quality of the studies included in these SRs. Clinical heterogeneity stemming from different patient selection criteria, interventions, and outcome definitions is a major issue. In spite of major advances in understanding different aspects of VUR in the last few decades, there is a paucity of randomized controlled trials in this field.

Update on male circumcision: prevention success and challenges ahead

This article reviews the findings of three trials of male circumcision for HIV prevention, with emphasis on the public health impact, cultural and safety concerns, implications for women, and the challenges of roll out. Three randomized trials in Africa demonstrated that adult male circumcision reduces HIV acquisition by 50% to 60%. As circumcision provides only partial protection, higher risk behaviors could nullify circumcision's effect. Additionally, circumcision among HIV-infected men does not directly reduce male-to-female HIV transmission among discordant couples, according to the results of a recent Ugandan study. The roll-out or full-scale implementation requires committed expansion into existing HIV prevention programs. Efforts should include attention to safety, implications for women, and risk compensation. Rapid, careful establishment of circumcision services is essential to optimize HIV prevention in countries with the highest prevalence.

Why circumcision is a biomedical imperative for the 21(st) century

Circumcision of males represents a surgical "vaccine" against a wide variety of infections, adverse medical conditions and potentially fatal diseases over their lifetime, and also protects their sexual partners. In experienced hands, this common, inexpensive procedure is very safe, can be pain-free and can be performed at any age. The benefits vastly outweigh risks. The enormous public health benefits include protection from urinary tract infections, sexually transmitted HIV, HPV, syphilis and chancroid, penile and prostate cancer, phimosis, thrush, and inflammatory dermatoses. In women circumcision of the male partner provides substantial protection from cervical cancer and chlamydia. Circumcision has socio-sexual benefits and reduces sexual problems with age. It has no adverse effect on penile sensitivity, function, or sensation during sexual arousal. Most women prefer the circumcised penis for appearance, hygiene and sex. Given the convincing epidemiological evidence and biological support, routine circumcision should be highly recommended by all health professionals.

Neonatal circumcision: effects on breastfeeding and outcomes associated with breastfeeding

AIM

There have been recurrent claims made that neonatal circumcision disrupts the development and maintenance of breastfeeding in infants. The aim of the current study was to use a longitudinal birth cohort study to examine the associations between neonatal circumcision status and both breastfeeding outcomes, and health and cognitive ability outcomes associated with breastfeeding.

METHOD

Data were obtained from the Christchurch Health and Development Study, a longitudinal study of over 1000 individuals born in Christchurch New Zealand in mid 1977. Data were obtained for male cohort members (n = 635) on circumcision status, breastfeeding outcomes, health outcomes in infancy and cognitive ability outcomes later in life.

RESULTS

Circumcision status was not significantly associated (P > 0.05) with breastfeeding outcomes in infancy, even following adjustment for covariate factors, including maternal age, family socio-economic status, ethnicity and birthweight. Also, circumcision status was not significantly associated (P > 0.05) with health in infancy and cognitive ability outcomes in later childhood, even after adjustment for covariate factors.

CONCLUSIONS

There was no evidence of an association between neonatal circumcision status and breastfeeding outcomes, or between circumcision status and health and cognitive ability outcomes associated with breastfeeding, and the findings do not support the view that neonatal circumcision disrupts breastfeeding.

Urinary tract infection in the newborn: clinical and radio imaging studies

The objective of this study was to assess clinical characteristics and results of radio imaging studies and compare community-acquired urinary tract infection (UTI) with nosocomial UTI in 301 neonates with UTI consecutively admitted to 28 neonatal units in Spain over 3 years (community-acquired UTI, n = 250; nosocomial UTI, n = 51). UTI was diagnosed in the presence of symptoms of infection together with any colony growth for a single pathogen from urine obtained by suprapubic aspiration, or >or=10(4) CFU/ml for a single pathogen from urine obtained by urethral catheterization. Abnormal renal ultrasound was present in 37.1% of cases (34% in community-acquired UTI and 54.5% in nosocomial UTI, P < 0.01). The voiding cystourethrography (VCUG) showed vesicoureteral reflux (VUR) in 27% of cases (23.8% in community-acquired UTI and 48.6% in nosocomial UTI, P < 0.01). In patients with abnormal renal ultrasound and VUR, renal scan with dimercaptosuccinic acid (DMSA) performed early after UTI revealed cortical defects in 69.5% of cases. However, in patients with abnormal renal ultrasound and normal VCUG, DMSA also revealed cortical defects in 39% of cases. The absence of VUR in neonates with UTI and abnormal renal ultrasound does not exclude the presence of cortical defects suggestive of pyelonephritis.

The current evidence based medical management of vesicoureteral reflux: The Sickkids protocol

Vesicoureteral reflux is a common clinical entity and is one of the keystones of the establishment of pediatric urology as a urological subspeciality. There has been continued evolution in the management of vesicoureteral reflux as new insights are gained on its role in renal damage. The optimal treatment algorithm remains controversial. This review aims to highlight the current literature on VUR and its association with urinary tract infections and renal damage. The protocol of management of a child with VUR followed at The Hospital for Sick Children, Toronto is described.

Trends in children's surgery in England

It is important to plan for the future provision of paediatric surgery and anaesthesia

Male circumcision to prevent HIV transmission and acquisition: what else do we need to know?

There is growing interest and controversy regarding the promotion of male circumcision (MC) for the prevention of HIV transmission in Africa. Three randomized controlled studies has so far been stopped prematurely as evidence accumulated that showed that circumcision was superior to no circumcision in preventing HIV acquisition among sexually active men in Africa. To some people, the evidence is overwhelming and MC should be promoted aggressively. Others suggest cautious decision making. This paper attempts to review a continuum of perceptions and suggest that the decision to scale-up male circumcision cannot just bebased on randomized controlled trial results.

[Prevention of penile cancer. Value of the HPV vaccination and circumcision]

Penile cancer is rare. Penile cancers appear predominantly in non-circumcised men. In addition, the majority of penile cancers are associated with human papillomavirus infection. The present manuscript is concerned with the value of circumcision and HPV vaccination in the prevention of penile cancer.

Male and female circumcision associated with prevalent HIV infection in virgins and adolescents in Kenya, Lesotho, and Tanzania

PURPOSE

Remarkable proportions of self-reported virgins and adolescents in eastern and southern Africa are infected with HIV, yet non-sexual routes of transmission have not been systematically investigated in such persons. Many observers in this region have recognized the potential for HIV transmission through unhygienic circumcision procedures. We assessed the relation between male and female circumcision (genital cutting) and prevalent HIV infection in Kenyan, Lesothoan, and Tanzanian virgins and adolescents.

METHODS

We analyzed data from recent cross-sectional national probability sample surveys of adolescents and adults in households, focusing on populations in which circumcision was common and usually occurred in puberty or later.

RESULTS

Circumcised male and female virgins were substantially more likely to be HIV infected than uncircumcised virgins (Kenyan females: 3.2% vs. 1.4%, odds ratio [OR] = 2.38; Kenyan males: 1.8% vs. 0%, OR undefined; Lesothoan males: 6.1% vs. 1.9%, OR 3.36; Tanzanian males: 2.9% vs. 1.0%, OR 2.99; weighted mean phi correlation = 0.07, 95% confidence interval, 0.03 to 0.11). Among adolescents, regardless of sexual experience, circumcision was just as strongly associated with prevalent HIV infection. However, uncircumcised adults were more likely to be HIV positive than circumcised adults. Self-reported sexual experience was independently related to HIV infection in adolescent Kenyan females, but was unrelated to HIV infection in adolescent Kenyan, Lesothoan, and Tanzanian males.

CONCLUSIONS

HIV transmission may occur through circumcision-related blood exposures in eastern and southern Africa.

Factors affecting renal scarring in posterior urethral valves

AIM

To retrospectively review the occurrence of renal scarring in patients with posterior urethral valves (PUV), and correlate it with various causative factors.

METHODS

The records of 52 patients treated for PUV by the authors were reviewed. Patients with vesico-ureteric reflex (VUR) dysplasia syndrome were excluded from the study. The patients were divided into group I (no renal scarring, n=18) and group II (renal scars present, n=34) based on dimercapto-succinic acid scans. The mode of treatment, presence/absence of breakthrough urinary tract infections (UTI), presence/absence of history of nocturnal/diurnal incontinence, presence/absence of VUR, stable postoperative serum creatinine, rate of drainage of ureters on diethylene triamine penta acetic acid (DTPA) scans and management of bladder dysfunction, if any, were noted. The presence or absence of renal scarring was statistically correlated with occurrence of any of the above factors.

RESULTS

Primary valve fulguration was performed in 41 patients and 11 patients had an initial vesicostomy. The median follow up was 3.5 years (range 1.5-15 years). Renal scarring was present in either kidney in 34 patients (bilateral 14, unilateral 20). The mode of initial treatment did not affect the incidence or rate of scarring. The preoperative and postoperative serum creatinine at the end of 1 year did not differ between the two groups. Presence/severity of VUR did not affect the pattern of renal scarring. A highly significant correlation between the occurrence of renal scarring and presence of diurnal incontinence (P< or =0.007, odds ratio=4.5) and breakthrough UTI (P< or =0.002, odds ratio=7.0) was observed. There was also correlation with slow drainage in the ureters on a DTPA scan (P< or =0.0005). Detrusor instability and low compliance on urodynamic assessment did not affect occurrence in the limited number of patients studied. The rate of somatic growth in both groups was retarded as compared to normal healthy counterparts.

CONCLUSION

Breakthrough UTI, diurnal incontinence and poor drainage of ureters on DTPA are associated with a higher incidence of renal scarring. Mode of initial treatment, presence or absence of VUR, and bladder abnormalities do not affect renal scarring in the short term.

Circumcision status and risk of sexually transmitted infection in young adult males: an analysis of a longitudinal birth cohort

OBJECTIVES

Previous research suggests that male circumcision may be a protective factor against the acquisition of sexually transmitted infections; however, studies examining this question have produced mixed results. The aim of this study was to examine the association between circumcision status and sexually transmitted infection risk using a longitudinal birth cohort study.

METHODS

Data were gathered as part of the Christchurch Health and Development Study, a 25-year longitudinal study of a birth cohort of New Zealand children. Information was obtained on: (1) the circumcision status of males in the cohort before 15 years old, (2) measures of self-reported sexually transmitted infection from ages 18 to 25 years, and (3) childhood, family, and related covariate factors.

RESULTS

Being uncircumcised had a statistically significant bivariate association with self-reported sexually transmitted infection. Adjustment for potentially confounding factors, including number of sexual partners and unprotected sex, as well as background and family factors related to circumcision, did not reduce the association between circumcision status and reports of sexually transmitted infection. Estimates of the population-attributable risk suggested that universal neonatal circumcision would have reduced rates of sexually transmitted infection in this cohort by 48.2%.

CONCLUSIONS

These findings suggest that uncircumcised males are at greater risk of acquiring sexually transmitted infection than circumcised males. Male circumcision may reduce the risk of sexually transmitted infection acquisition and transmission by up to one half, suggesting substantial benefits accruing from routine neonatal circumcision.

Topical hydrocortisone and physiotherapy for nonretractile physiologic phimosis in infants

The effect of hydrocortisone (HC), the steroid of lowest potency, and physiotherapy (PT) on non-retractile physiologic phimosis (PP) and the reduction of subsequent recurrent UTI was evaluated in male infants with UTI. Seventy-eight male infants with febrile UTI and nonretractile PP were prospectively randomized into HC (Plancol, n=39) and control (Vaseline, n=39) groups. Topical application of HC as a thin film around the preputial margin twice a day for four weeks with PT was instructed. The response rate in the HC group was 89.7% (35/39), which was significantly higher than the rate (20.5%; 8/39) in the control group (P<0.05). In the HC group, the response rate was much higher (96.1%) in the subgroup with PT than in the group without PT. Most of the response (88.5%) was observed within two weeks. During the following year, the recurrent rate of UTI was 7.1% (2/28) in the infants with retractile prepuces, which was significantly less than than the rate (29.6%; 8/27) in infants with nonretractile prepuces (P<0.05). In conclusion, topical HC and PT for 2-4 weeks proved to be a simple, safe and effective treatment for nonretractile PP in infants with UTI, and this procedure was beneficial in reducing recurrent UTI.

Acute urinary tract infection--evaluation and treatment

PURPOSE OF REVIEW

The evaluation and management of urinary tract infections in infants and children is undergoing changes due to the impact of evidence-based studies and new technology.

RECENT FINDINGS

The uncircumcised male infant is at increased risk for a urinary tract infection, but there is marked difference in the frequency of circumcision carried out to lower the risk of infection in the United States compared with Europe. Commentaries presenting different interpretations of the current data make for interesting reading and present the many sides of this issue. Vesicoureteric reflux, previously viewed as the major risk factor for acquired renal damage, now shares this role with nonreflux nephropathy. Procalcitonin has been evaluated as a biochemical tool to identify patients at risk for kidney damage, with dimercaptosuccinic acid scintigraphy as the reference method to detect renal scarring.

SUMMARY

The previously accepted concept that vesicoureteric reflux as detected radiologically is almost always the key factor in acquired renal injury secondary to a urinary tract infection is no longer accepted. Current studies show that nonreflux nephropathy occurs as often as reflux nephropathy. There is now a question of the value of imaging studies designed to identify vesicoureteric reflux and of the use of suppressive antibiotics for vesicoureteric reflux. There exist useful evidence-based studies for antibiotic therapy for upper and lower tract urinary tract infections, but no such data are available for guidance in selecting imaging studies for the infant or child with a first febrile urinary tract infection.