Neonates living with enterostomy following necrotising enterocolitis are at high risk of becoming severely underweight.

Necrotising enterocolitis (NEC) is often managed with a temporary enterostomy. Neonates with enterostomy are at risk of growth retardation during critical neurodevelopment. We examined their growth using z-score. We identified all patients with enterostomy from NEC in two neonatal surgical units (NSU) during January 2012-December 2016. Weight-for-age z-score was calculated at birth, stoma formation and closure, noting severely underweight as z < - 3. We compared those kept in NSU until stoma closure with those discharged to local units or home (LU/H) with a stoma. A total of 74 patients were included. By stoma closure, 66 (89%) had deteriorated in z-score with 31 (42%) being severely underweight. There was no difference in z-score at stoma closure between NSU and LU/H despite babies sent to LU/H having a more distal stoma, higher birth weight and gestational age. Babies in LU/H spent a much shorter period on parenteral nutrition while living with their stoma for longer, many needing readmission.Conclusion: Growth failure is a common and severe problem in babies living with enterostomy following NEC. z-score allowed growth trajectory to be accounted for in nutrition prescription and timing of stoma closure. Care during this period should be focused on minimising harm.What is Known:• Necrotising enterocolitis (NEC) is a life-threatening condition affecting predominately premature and very low birth weight neonates. Emergency treatment with temporary enterostomy often leads to growth failure.• There is no consensus on the optimal timing for stoma reversal, hence prolonging impact on growth during crucial developmental periods. Both malnutrition and surgical NEC are independently associated with poor neurodevelopment outcome.What is New:• Our study found growth in 89% of babies deteriorated while living with a stoma, with 42% having a weight-for-age z-score < - 3, meeting the WHO criteria of being severely underweight, despite judicial use of parenteral nutrition. Applying z-score to weight measurements will allow growth trajectory to be accounted for in clinical decisions, including nutrition prescription (both enteral and parenteral), and guide timing of stoma closure.• Surgeons who target stoma closure at a certain weight risk waiting for an indefinite period of time, during which babies' growth may falter.

Outcome of stoma closure in babies with necrotising enterocolitis: early vs late closure.

Newborns undergoing surgery for necrotizing enterocolitis (NEC) often require a stoma. Currently, there is no consensus regarding the best time for stoma closure (SC). Our aim was to determine the outcomes of early versus late closure. METHODS: Retrospective analysis of patients who underwent SC following stoma formation for NEC between Jan 2009 and July 2015 was done. Early (EC) versus late closure (LC) was defined as less than 10 weeks versus at or after 10 weeks of stoma formation. RESULTS: Of 36 patients, M:F was 23:13. Indications for laparotomy were pneumoperitoneum (30) and gangrene (6). Postoperatively, 9/15 (60.0%) of EC group required ventilator support versus none in LC group (p < 0.05). It took longer to establish full feeds following EC (12 days) versus LC (8 days). Median duration of postoperative hospital stay following EC was 31 days (18-35) versus 7 days (4-54) following LC. Three patients were re-operated for intestinal obstruction (two following EC, one following LC). Three patients developed incisional hernia after EC versus none after LC (p < 0.05). One patient died after EC due to staphylococcus septicaemia. CONCLUSION: Early closure before 10 weeks of formation for NEC patients is associated with significant morbidity, increased ventilator requirements and chances of developing incisional hernia.

Can common serum biomarkers predict complicated appendicitis in children?

PURPOSE: As appendicitis in children can be managed differently according to the severity of the disease, we investigated whether commonly used serum biomarkers on admission could distinguish between simple and complicated appendicitis. METHODS: Admission white blood cell (WBC), neutrophil (NEU), and C-reactive protein (CRP) levels were analysed by ROC curve, and Kruskal-Wallis and contingency tests. Patients were divided according to age and histology [normal appendix (NA), simple appendicitis (SA), complicated appendicitis (CA)]. RESULTS: Of 1197 children (NA = 186, SA = 685, CA = 326), 7% were <5 years, 55% 5-12, 38% 13-17. CA patients had higher CRP and WBC levels than NA and SA (p < 0.0001). NEU levels were lower in NA compared to SA or CA (p < 0.0001), but were similar between SA and CA (p = 0.6). CA patients had higher CRP and WBC levels than SA patients in 5-12- (p < 0.0001) and 13-17-year groups (p = 0.0075, p = 0.005), but not in <5-year group (p = 0.72, p = 0.81). We found CRP >40 mg/L in 58% CA and 37% SA (p < 0.0001), and WBC >15 × 109/L in 58% CA and 43% SA (p < 0.0001). CONCLUSIONS: Admission CRP and WBC levels may help the clinician predict complicated appendicitis in children older than 5 years of age. Early distinction of appendicitis severity using these tests may guide caregivers in the preoperative decision-making process.

A modified technique of laparoscopic mobilisation and transfer of intra-abdominal testis via inguinal canal.

Several techniques have been described for mobilising intra-abdominal testis (IAT) into the scrotum. Many are associated with significant morbidity. We hereby introduce our modification of the technique that is safe and reproducible. Surgical technique using a nylon tape to railroad instruments into the peritoneal cavity to minimise false passage and trauma is described in detail. Once the testis is delivered out of the scrotal wound, further division of restrictive bands to mobilise the testis is carried out laparoscopically. These steps are not previously described in the literature. A retrospective study of consecutive patients with IAT undergoing surgical intervention by a single surgeon over a period of 15 years has been included to demonstrate outcome. Twenty-five patients with unilateral IAT (10R, 15L) and 2 patients with bilateral IAT, a total of 29 IAT, underwent laparoscopic orchidopexy over the period 1997-2012. Median age of the patients was 3.0 years. One-stage testicular vessel preserving (VP) orchidopexy was performed in 20 testes, Fowler-Stephen (FS), vessel sacrificing orchidopexy (3 one-stage and 6 two-stage) was required in 9 testes. At follow-up, atrophy was detected in 1 (5.0 %) and 2 (22.2 %) patients of the VP and FS groups respectively. The railroading technique of transferring IAT into the scrotum via the inguinal canal under laparoscopic guidance minimises tissue trauma. It negates the need to create new tissue opening. It is reproducible with a testicular atrophy rate comparable to published literature.

Incarcerated inguinal hernia management in children: 'a comparison of the open and laparoscopic approach'.

PURPOSE: To compare the outcomes of management of incarcerated inguinal hernia by open versus laparoscopic approach. METHODS: This is a retrospective analysis of incarcerated inguinal hernina in a paediatric surgery centre involving four consultants. Manual reduction was attempted in all and failure was managed by emergency surgery. RESULTS: The laparoscopy group had 27 patients. Four patients failed manual reduction and underwent emergency laparoscopic surgery. Three of them had small bowel strangulation which was reduced laparoscopically. The strangulated bowel was dusky in colour initially but changed to normal colour subsequently under vision. The fourth patient required appendectomy for strangulated appendix. One patient had concomitant repair of umbilical hernia and one patient had laparoscopic pyloromyotomy at the same time. One patient had testicular atrophy, one had hydrocoele and one had recurrence of hernia on the asymptomatic side. The open surgery group had 45 patients. Eleven patients had failed manual reduction requiring emergency surgery, of these two required resection and anastomosis of small intestine. One patient in this group had concomitant repair of undescended testis. There was no recurrence in this group, one had testicular atrophy and seven had metachronous hernia. CONCLUSIONS: Both open herniotomy and laparoscopic repair offer safe surgery with comparable outcomes for incarcerated inguinal hernia in children. Laparoscopic approach and hernioscopy at the time of open approach appear to show the advantage of repairing the contralateral patent processus vaginalis at the same time and avoiding metachronous inguinal hernia.

Public health lessons from severe acute respiratory syndrome a decade later.

The outbreak of severe acute respiratory syndrome in 2002-2003 exacted considerable human and economic costs from countries involved. It also exposed major weaknesses in several of these countries in coping with an outbreak of a newly emerged infectious disease. In the 10 years since the outbreak, in addition to the increase in knowledge of the biology and epidemiology of this disease, a major lesson learned is the value of having a national public health institute that is prepared to control disease outbreaks and designed to coordinate a national response and assist localities in their responses.

Recombinant coxsackievirus A2 and deaths of children, Hong Kong, 2012.

A natural recombinant of coxsackievirus A2 was found in 4 children with respiratory symptoms in Hong Kong, China, during the summer of 2012. Two of these children died. Vigilant monitoring of this emerging recombinant enterovirus is needed to prevent its transmission to other regions.

Infection fatality risk of the pandemic A(H1N1)2009 virus in Hong Kong.

One measure of the severity of a pandemic influenza outbreak at the individual level is the risk of death among people infected by the new virus. However, there are complications in estimating both the numerator and denominator. Regarding the numerator, statistical estimates of the excess deaths associated with influenza virus infections tend to exceed the number of deaths associated with laboratory-confirmed infection. Regarding the denominator, few infections are laboratory confirmed, while differences in case definitions and approaches to case ascertainment can lead to wide variation in case fatality risk estimates. Serological surveillance can be used to estimate the cumulative incidence of infection as a denominator that is more comparable across studies. We estimated that the first wave of the influenza A(H1N1)pdm09 virus in 2009 was associated with approximately 232 (95% confidence interval: 136, 328) excess deaths of all ages in Hong Kong, mainly among the elderly. The point estimates of the risk of death on a per-infection basis increased substantially with age, from below 1 per 100,000 infections in children to 1,099 per 100,000 infections in those 60-69 years of age. Substantial variation in the age-specific infection fatality risk complicates comparison of the severity of different influenza strains.

Excess mortality associated with influenza A and B virus in Hong Kong, 1998-2009.

BACKGROUND: Although deaths associated with laboratory-confirmed influenza virus infections are rare, the excess mortality burden of influenza estimated from statistical models may more reliably quantify the impact of influenza in a population. METHODS: We applied age-specific multiple linear regression models to all-cause and cause-specific mortality rates in Hong Kong from 1998 through 2009. The differences between estimated mortality rates in the presence or absence of recorded influenza activity were used to estimate influenza-associated excess mortality. RESULTS: The annual influenza-associated all-cause excess mortality rate was 11.1 (95% confidence interval [CI], 7.2-14.6) per 100,000 person-years. We estimated an average of 751 (95% CI, 488-990) excess deaths associated with influenza annually from 1998 through 2009, with 95% of the excess deaths occurring in persons aged ≥65 years. Most of the influenza-associated excess deaths were from respiratory (53%) and cardiovascular (18%) causes. Influenza A(H3N2) epidemics were associated with more excess deaths than influenza A(H1N1) or B during the study period. CONCLUSIONS: Influenza was associated with a substantial number of excess deaths each year, mainly among the elderly, in Hong Kong in the past decade. The influenza-associated excess mortality rates were generally similar in Hong Kong and the United States.

Molecular characterization of the 2011 Hong Kong scarlet fever outbreak.

A scarlet fever outbreak occurred in Hong Kong in 2011. The majority of cases resulted in the isolation of Streptococcus pyogenes emm12 with multiple antibiotic resistances. Phylogenetic analysis of 22 emm12 scarlet fever outbreak isolates, 7 temporally and geographically matched emm12 non-scarlet fever isolates, and 18 emm12 strains isolated during 2005-2010 indicated the outbreak was multiclonal. Genome sequencing of 2 nonclonal scarlet fever isolates (HKU16 and HKU30), coupled with diagnostic polymerase chain reaction assays, identified 2 mobile genetic elements distributed across the major lineages: a 64.9-kb integrative and conjugative element encoding tetracycline and macrolide resistance and a 46.4-kb prophage encoding superantigens SSA and SpeC and the DNase Spd1. Phenotypic comparison of HKU16 and HKU30 with the S. pyogenes M1T1 strain 5448 revealed that HKU16 displays increased adherence to HEp-2 human epithelial cells, whereas HKU16, HKU30, and 5448 exhibit equivalent resistance to neutrophils and virulence in a humanized plasminogen murine model. However, in contrast to M1T1, the virulence of HKU16 and HKU30 was not associated with covRS mutation. The multiclonal nature of the emm12 scarlet fever isolates suggests that factors such as mobile genetic elements, environmental factors, and host immune status may have contributed to the 2011 scarlet fever outbreak.

Clinical course and treatment interventions for adolescents who vaped during the COVID-19 pandemic.

Vaping nicotine and marijuana have been increasing among adolescents in the past 5 years. Tetrahydrocannabinol is the psychoactive cannabinoid in marijuana. The COVID-19 pandemic created gaps in healthcare access and visits, making it difficult to collect accurate data on adolescent vaping, willingness to quit and methods used to quit. In addition, the literature lacks information regarding effective evidence-based treatment measures for adolescents who vape. In this report, we seek to address this using two patient cases and detailing the interventions a managed care organisation enacted during this timeframe. Our investigation revealed a relationship between social stressors and vaping among teens. Addressing these underlying stressors and eliciting and treating mental health symptoms and polysubstance use appears to be critical to curbing vaping.

Scarlet fever epidemic, Hong Kong, 2011.

More than 900 cases of scarlet fever were recorded in Hong Kong during January-July, 2011. Six cases were complicated by toxic shock syndrome, of which 2 were fatal. Pulsed-field gel electrophoresis patterns suggested a multiclonal epidemic; emm12 was the predominant circulating type. We recommend genetic testing of and antimicrobial resistance monitoring for this reportable disease.

Epidemiological characteristics of 2009 (H1N1) pandemic influenza based on paired sera from a longitudinal community cohort study.

BACKGROUND: While patterns of incidence of clinical influenza have been well described, much uncertainty remains over patterns of incidence of infection. The 2009 pandemic provided both the motivation and opportunity to investigate patterns of mild and asymptomatic infection using serological techniques. However, to date, only broad epidemiological patterns have been defined, based on largely cross-sectional study designs with convenience sampling frameworks. METHODS AND FINDINGS: We conducted a paired serological survey of a cohort of households in Hong Kong, recruited using random digit dialing, and gathered data on severe confirmed cases from the public hospital system (>90% inpatient days). Paired sera were obtained from 770 individuals, aged 3 to 103, along with detailed individual-level and household-level risk factors for infection. Also, we extrapolated beyond the period of our study using time series of severe cases and we simulated alternate study designs using epidemiological parameters obtained from our data. Rates of infection during the period of our study decreased substantially with age: for 3-19 years, the attack rate was 39% (31%-49%); 20-39 years, 8.9% (5.3%-14.7%); 40-59 years, 5.3% (3.5%-8.0%); and 60 years or older, 0.77% (0.18%-4.2%). We estimated parameters for a parsimonious model of infection in which a linear age term and the presence of a child in the household were used to predict the log odds of infection. Patterns of symptom reporting suggested that children experienced symptoms more often than adults. The overall rate of confirmed pandemic (H1N1) 2009 influenza (H1N1pdm) deaths was 7.6 (6.2-9.5) per 100,000 infections. However, there was substantial and progressive increase in deaths per 100,000 infections with increasing age from 0.66 (0.65-0.86) for 3-19 years up to 220 (50-4,000) for 60 years and older. Extrapolating beyond the period of our study using rates of severe disease, we estimated that 56% (43%-69%) of 3-19 year olds and 16% (13%-18%) of people overall were infected by the pandemic strain up to the end of January 2010. Using simulation, we found that, during 2009, larger cohorts with shorter follow-up times could have rapidly provided similar data to those presented here. CONCLUSIONS: Should H1N1pdm evolve to be more infectious in older adults, average rates of severe disease per infection could be higher in future waves: measuring such changes in severity requires studies similar to that described here. The benefit of effective vaccination against H1N1pdm infection is likely to be substantial for older individuals. Revised pandemic influenza preparedness plans should include prospective serological cohort studies. Many individuals, of all ages, remained susceptible to H1N1pdm after the main 2009 wave in Hong Kong. Please see later in the article for the Editors' Summary.

Estimating infection attack rates and severity in real time during an influenza pandemic: analysis of serial cross-sectional serologic surveillance data.

BACKGROUND: In an emerging influenza pandemic, estimating severity (the probability of a severe outcome, such as hospitalization, if infected) is a public health priority. As many influenza infections are subclinical, sero-surveillance is needed to allow reliable real-time estimates of infection attack rate (IAR) and severity. METHODS AND FINDINGS: We tested 14,766 sera collected during the first wave of the 2009 pandemic in Hong Kong using viral microneutralization. We estimated IAR and infection-hospitalization probability (IHP) from the serial cross-sectional serologic data and hospitalization data. Had our serologic data been available weekly in real time, we would have obtained reliable IHP estimates 1 wk after, 1-2 wk before, and 3 wk after epidemic peak for individuals aged 5-14 y, 15-29 y, and 30-59 y. The ratio of IAR to pre-existing seroprevalence, which decreased with age, was a major determinant for the timeliness of reliable estimates. If we began sero-surveillance 3 wk after community transmission was confirmed, with 150, 350, and 500 specimens per week for individuals aged 5-14 y, 15-19 y, and 20-29 y, respectively, we would have obtained reliable IHP estimates for these age groups 4 wk before the peak. For 30-59 y olds, even 800 specimens per week would not have generated reliable estimates until the peak because the ratio of IAR to pre-existing seroprevalence for this age group was low. The performance of serial cross-sectional sero-surveillance substantially deteriorates if test specificity is not near 100% or pre-existing seroprevalence is not near zero. These potential limitations could be mitigated by choosing a higher titer cutoff for seropositivity. If the epidemic doubling time is longer than 6 d, then serial cross-sectional sero-surveillance with 300 specimens per week would yield reliable estimates when IAR reaches around 6%-10%. CONCLUSIONS: Serial cross-sectional serologic data together with clinical surveillance data can allow reliable real-time estimates of IAR and severity in an emerging pandemic. Sero-surveillance for pandemics should be considered.

The infection attack rate and severity of 2009 pandemic H1N1 influenza in Hong Kong.

BACKGROUND: Serial cross-sectional data on antibody levels to the 2009 pandemic H1N1 influenza A virus from a population can be used to estimate the infection attack rates and immunity against future infection in the community. METHODS: From April through December 2009, we obtained 12,217 serum specimens from blood donors (aged 16-59 years), 2520 specimens from hospital outpatients (aged 5-59 years), and 917 specimens from subjects involved in a community pediatric cohort study (aged 5-14 years). We estimated infection attack rates by comparing the proportions of specimens with antibody titers ≥ 1:40 by viral microneutralization before and after the first wave of the pandemic. Estimates were validated using paired serum samples from 324 individuals that spanned the first wave. Combining these estimates with epidemiologic surveillance data, we calculated the proportion of infections that led to hospitalization, admission to the intensive care unit (ICU), and death. RESULTS: We found that 3.3% and 14% of persons aged 5-59 years had antibody titers ≥ 1:40 before and after the first wave, respectively. The overall attack rate was 10.7%, with age stratification as follows: 43.4% in persons aged 5-14 years, 15.8% in persons aged 15-19 years, 11.8% in persons aged 20-29 years, and 4%-4.6% in persons aged 30-59 years. Case-hospitalization rates were 0.47%-0.87% among persons aged 5-59 years. Case-ICU rates were 7.9 cases per 100,000 infections in persons aged 5-14 years and 75 cases per 100,000 infections in persons aged 50-59 years, respectively. Case-fatality rates were 0.4 cases per 100,000 infections in persons aged 5-14 years and 26.5 cases per 100,000 infections in persons aged 50-59 years, respectively. CONCLUSIONS: Almost half of all school-aged children in Hong Kong were infected during the first wave. Compared with school children aged 5-14 years, older adults aged 50-59 years had 9.5 and 66 times higher risks of ICU admission and death if infected, respectively.

School closure and mitigation of pandemic (H1N1) 2009, Hong Kong.

In Hong Kong, kindergartens and primary schools were closed when local transmission of pandemic (H1N1) 2009 was identified. Secondary schools closed for summer vacation shortly afterwards. By fitting a model of reporting and transmission to case data, we estimated that transmission was reduced approximately 25% when secondary schools closed.

The effective reproduction number of pandemic influenza: prospective estimation.

BACKGROUND: Timely estimation of the transmissibility of a novel pandemic influenza virus was a public health priority in 2009. METHODS: We extended methods for prospective estimation of the effective reproduction number (Rt) over time in an emerging epidemic to allow for reporting delays and repeated importations. We estimated Rt based on case notifications and hospitalizations associated with laboratory-confirmed pandemic (H1N1) 2009 virus infections in Hong Kong from June through October 2009. RESULTS: Rt declined from around 1.4-1.5 at the start of the local epidemic to around 1.1-1.2 later in the summer, suggesting changes in transmissibility perhaps related to school vacations or seasonality. Estimates of Rt based on hospitalizations of confirmed H1N1 cases closely matched estimates based on case notifications. CONCLUSION: Real-time monitoring of the effective reproduction number is feasible and can provide useful information to public health authorities for situational awareness and calibration of mitigation strategies.

A comparative epidemiologic analysis of SARS in Hong Kong, Beijing and Taiwan.

BACKGROUND: The 2002-2003 Severe Acute Respiratory Syndrome (SARS) outbreak infected 8,422 individuals leading to 916 deaths around the world. However, there have been few epidemiological studies of SARS comparing epidemiologic features across regions. The aim of this study is to identify similarities and differences in SARS epidemiology in three populations with similar host and viral genotype. METHODS: We present a comparative epidemiologic analysis of SARS, based on an integrated dataset with 3,336 SARS patients from Hong Kong, Beijing and Taiwan, epidemiological and clinical characteristics such as incubation, onset-to-admission, onset-to-discharge and onset-to-death periods, case fatality ratios (CFRs) and presenting symptoms are described and compared between regions. We further explored the influence of demographic and clinical variables on the apparently large differences in CFRs between the three regions. RESULTS: All three regions showed similar incubation periods and progressive shortening of the onset-to-admission interval through the epidemic. Adjusted for sex, health care worker status and nosocomial setting, older age was associated with a higher fatality, with adjusted odds ratio (AOR): 2.10 (95% confidence interval: 1.45, 3.04) for those aged 51-60; AOR: 4.57 (95% confidence interval: 3.32, 7.30) for those aged above 60 compared to those aged 41-50 years. Presence of pre-existing comorbid conditions was also associated with greater mortality (AOR: 1.74; 95% confidence interval: 1.36, 2.21). CONCLUSION: The large discrepancy in crude fatality ratios across the three regions can only be partly explained by epidemiological and clinical heterogeneities. Our findings underline the importance of a common data collection platform, especially in an emerging epidemic, in order to identify and explain consistencies and differences in the eventual clinical and public health outcomes of infectious disease outbreaks, which is becoming increasingly important in our highly interconnected world.

Preservation of glanular cleft in the configuration of a vertical slit neomeatus in modified mathieu hypospadias repair.

BACKGROUND: The aim of this study is to review the results of modified Mathieu's repair in a single surgeon's series. The technique involved preserving the apical part of the glanular cleft including the lips, part of the un-formed glanular meatus in the reconstruction of a vertical slit neomeatus. The achievement of a vertical slit neomeatus was critically assessed. MATERIALS AND METHODS: A retrospective analysis was carried out for all cases of Mathieu's repair done by a single surgeon over the past 22 years (1995-2017). Inclusion criteria included all cases of coronal, subcoronal and distal penile hypospadias. Cases done as redo secondary Mathieu's procedure were also included irrespective of the type of primary procedure. RESULTS: A total of 97 cases fulfilled the inclusion criteria. 91 patients had a primary Mathieu's procedure. Six patients had a Mathieu's repair as a secondary operation. The complications included 4 fistulas (4.12%), 3 meatal retractions (3.09%) and 2 mild stenosis (2.06%). There were no breakdowns of the repair Ninety-four patients (96.90%) had a glanular vertical slit neomeatus. This included patients with a fistula and both patients with mild stenosis. All fistulas were successfully closed in a single attempt. Four patients (4.12%) had a slight splaying of the lower end of the meatus and three circular neomeatus (3.09%). Both cases of stenosis responded well to dilatation. CONCLUSION: Mathieu's repair is an old and time-tested technique used in surgery of distal hypospadias. With modification aiming to preserve the apical part of the glanular cleft adopted, a vertical slit neomeatus can be achieved readily as shown by our series and major complications appear rather uncommon.

Clinical prognostic rules for severe acute respiratory syndrome in low- and high-resource settings.

BACKGROUND: An accurate prognostic model for patients with severe acute respiratory syndrome (SARS) could provide a practical clinical decision aid. We developed and validated prognostic rules for both high- and low-resource settings based on data available at the time of admission. METHODS: We analyzed data on all 1755 and 291 patients with SARS in Hong Kong (derivation cohort) and Toronto (validation cohort), respectively, using a multivariable logistic scoring method with internal and external validation. Scores were assigned on the basis of patient history in a basic model, and a full model additionally incorporated radiological and laboratory results. The main outcome measure was death. RESULTS: Predictors for mortality in the basic model included older age, male sex, and the presence of comorbid conditions. Additional predictors in the full model included haziness or infiltrates on chest radiography, less than 95% oxygen saturation on room air, high lactate dehydrogenase level, and high neutrophil and low platelet counts. The basic model had an area under the receiver operating characteristic (ROC) curve of 0.860 in the derivation cohort, which was maintained on external validation with an area under the ROC curve of 0.882. The full model improved discrimination with areas under the ROC curve of 0.877 and 0.892 in the derivation and validation cohorts, respectively. CONCLUSION: The model performs well and could be useful in assessing prognosis for patients who are infected with re-emergent SARS.