Effects of single nucleotide polymorphisms in the RANTES promoter region in healthy and HIV-infected indigenous Chinese

We determined the occurrence of the single nucleotide polymorphisms (SNPs) -403A/G and -28C/G in the promoter region of RANTES in 1082 Chinese blood donors from northern and southern China and 249 HIV patients from southern China. Compared to healthy adults, Chinese AIDS patients had a significantly higher frequency of the -403G allele and haplotype I, -403G/-28C (P < 0.05), and a lower frequency of the -403A/A genotype (P < 0.01). Symptomatic patients had a higher frequency of the -28G allele and a lower frequency of the -28C/C genotype (P < or = 0.01). The plasma RANTES level was significantly lower in blood donors homozygous for haplotype I than in those who were homozygous for haplotypes II and III (P < 0.05). The frequency of the -403G allele was found to be higher in Chinese than in indigenous Africans, but lower than in Caucasians, Hispanics, and African Americans. The frequency of the -28G allele was comparable in Chinese and Japanese; this allele is rare in other ethnic groups. Results suggest that -403G may be associated with increased susceptibility to HIV infection, while -28G may be associated with advanced disease progression. The impact of SNPs on HIV infection appears to be unique in Chinese.

In vitro susceptibility of 10 clinical isolates of SARS coronavirus to selected antiviral compounds

Effective antiviral agents are urgently needed to combat the possible return of severe acute respiratory syndrome (SARS). Commercial antiviral agents and pure chemical compounds extracted from traditional Chinese medicinal herbs were screened against 10 clinical isolates of SARS coronavirus by neutralisation tests with confirmation by plaque reduction assays. Interferon-beta-1a, leukocytic interferon-alpha, ribavirin, lopinavir, rimantadine, baicalin and glycyrrhizin showed antiviral activity. The two interferons were only active if the cell lines were pre-incubated with the drugs 16 h before viral inoculation. Results were confirmed by plaque reduction assays. Antiviral activity varied with the use of different cell lines. Checkerboard assays for synergy were performed showing combinations of interferon beta-1a or leukocytic interferon-alpha with ribavirin are synergistic. Since the clinical and toxicity profiles of these agents are well known, they should be considered either singly or in combination for prophylaxis or treatment of SARS in randomised placebo controlled trials in future epidemics.

Direct detection of rifampin-resistant mycobacterium tuberculosis in respiratory specimens by PCR-DNA sequencing

This study evaluated the feasibility of a molecular strategy based on identification of Mycobacterium tuberculosis by IS6110 PCR or Cobas Amplicor PCR, and rpoB PCR-DNA sequencing of the 81-bp rifampin resistance determining region (RRDR) for direct detection of rifampin resistance in respiratory specimens. A collection of 2,138 respiratory specimens and 352 nonduplicate M. tuberculosis isolates (including 233 isolates from the evaluated respiratory specimens and an additional collection of 119 stored isolates) from Southern China was investigated. Using culture as the reference test, the overall diagnostic sensitivities of an acid-fast bacillus (AFB) smear, Cobas Amplicor PCR, IS6110 PCR were 54.5% (156 of 286), 86.7% (248 of 286), and 89.2% (255 of 286), respectively. The sensitivities of the rpoB PCR for the specimens with positive AFB smears and with positive PCR results in the IS6110 PCR and/or Cobas Amplicor PCR were 100% (156 of 156) and 92.3% (239 of 259), respectively. Of the 352 nonduplicate M. tuberculosis isolates, the agar proportion method for rifampin reported 39 resistant strains. Full agreement (352 of 352) was found with the agar proportion method and the genotype inferred from the rpoB DNA sequencing data for rifampin. Thirty-nine mutations of nine distinct kinds, eight point mutations, and one deletion within the RRDR were found in the 39 resistant strains. For the direct DNA sequencing performed on rpoB PCR-positive respiratory specimens, the concordance with the agar proportion method and the subsequent PCR-sequencing for the culture isolate was 100%. This strategy has potential application for direct and rapid diagnosis of rifampin-resistant M. tuberculosis in IS6110 PCR or Cobas Amplicor PCR-positive respiratory specimens.

Severe acute respiratory syndrome

Severe acute respiratory syndrome (SARS) was caused by a previously unrecognized animal coronavirus that exploited opportunities provided by 'wet markets' in southern China to adapt to become a virus readily transmissible between humans. Hospitals and international travel proved to be 'amplifiers' that permitted a local outbreak to achieve global dimensions. In this review we will discuss the substantial scientific progress that has been made towards understanding the virus-SARS coronavirus (SARS-CoV)-and the disease. We will also highlight the progress that has been made towards developing vaccines and therapies The concerted and coordinated response that contained SARS is a triumph for global public health and provides a new paradigm for the detection and control of future emerging infectious disease threats.

The aetiology, origins, and diagnosis of severe acute respiratory syndrome

Severe acute respiratory syndrome (SARS) is a new infectious disease that first emerged in Guangdong province, China, in November, 2002. A novel coronavirus was later identified in patients with SARS. The detection of the virus in these patients, its absence in healthy controls or other patients with atypical pneumonia, and the reproduction of a similar disease in a relevant animal model fulfilled Koch's postulates for implicating this coronavirus as the causal agent of SARS. The full genome sequence was determined within weeks of the virus's identification. The rapid progress in the aetiology, the development of laboratory diagnostic tests, and the defining of routes of viral transmission were facilitated through a unique WHO-coordinated virtual network of laboratories, which shared information on a real-time basis through daily teleconferences. Subsequent studies have indicated that the SARS coronavirus is of animal origin, that its precursor is still present in animal populations within the region, and that live-animal markets in southern China may have provided the animal-human interphase that allowed this precursor virus to adapt to human-human transmission. These findings underscore the potential for the re-emergence of SARS and the need for laboratory tests for early diagnosis. However, the low viral load in the respiratory tract makes early diagnosis of SARS a diagnostic challenge, although improvements in the sensitivity of molecular diagnostic methods continue to be made.

Spontaneous pneumomediastinum in patients with severe acute respiratory syndrome

Spontaneous pneumomediastinum (SP) unrelated to assisted ventilation is a newly recognised complication of severe acute respiratory syndrome (SARS). The objective of the present study was to examine the incidence, risk factors and the outcomes of SP in a cohort of SARS victims from a community outbreak. Data were retrieved from a prospectively collected database of virologically confirmed SARS patients. One hundred and twelve cases were analysable, with 13 patients developing SP (11.6%) at a mean +/- SD of 19.6 +/- 4.6 days from symptom onset. Peak lactate dehydrogenase level was associated with the development of SP. SP was associated with increased intubation and a trend towards death. Drainage was required in five cases. For patients who survived, the SP and/or the associated pneumothoraces took a median of 28 days (interquartile range: 15-45 days) to resolve completely. In conclusion, spontaneous pneumomediastinum appeared to be a frequent complication of severe acute respiratory syndrome. Further research is needed to investigate its pathogenesis.

Direct detection of Mycobacterium tuberculosis in clinical specimens using single-tube biotinylated nested polymerase chain reaction-enzyme linked immunoassay (PCR-ELISA)

A biotinylated single-tube nested polymerase chain reaction (PCR) assay with microwell hybridization assay (bPCR-ELISA) was developed for detection of Mycobacterium tuberculosis in clinical specimens. A total of 659 specimens (601 respiratory specimens and 58 nonrespiratory specimens) were collected for evaluation using three DNA amplification techniques: newly designed bPCR-ELISA, in-house single-tube nested PCR for IS6110 gene sequence (nPCR), and commercial automated assays, the Cobas Amplicor System from Roche Diagnostic Systems (aPCR). Sixty-four (9.7%) specimens were culture-positive for M. tuberculosis. Eleven (1.7%) specimens culture-positive for nontuberculosis mycobacteria were negative by all three PCR assays. The resolved performance of bPCR-ELISA, nPCR, and aPCR was found at sensitivities of 97%, 94%, and 97%, respectively. All three PCR assays exhibited a 100% specificity. In evaluation of bPCR-ELISA, a clear distinction between PCR-positive and PCR-negative specimens when an OD405 value of 0.6 was chosen as cut-off. With serial dilutions of M. tuberculosis H37Rv DNA, the detection limit of bPCR-ELISA was found to be 0.75 cfu per reaction at OD405 value of 0.6. Our developed bPCR-ELISA provides a highly sensitive and low-costing molecular diagnosis suitable for developing countries with high prevalence of tuberculosis.

Genesis of a highly pathogenic and potentially pandemic H5N1 influenza virus in eastern Asia

A highly pathogenic avian influenza virus, H5N1, caused disease outbreaks in poultry in China and seven other east Asian countries between late 2003 and early 2004; the same virus was fatal to humans in Thailand and Vietnam. Here we demonstrate a series of genetic reassortment events traceable to the precursor of the H5N1 viruses that caused the initial human outbreak in Hong Kong in 1997 (refs 2-4) and subsequent avian outbreaks in 2001 and 2002 (refs 5, 6). These events gave rise to a dominant H5N1 genotype (Z) in chickens and ducks that was responsible for the regional outbreak in 2003-04. Our findings indicate that domestic ducks in southern China had a central role in the generation and maintenance of this virus, and that wild birds may have contributed to the increasingly wide spread of the virus in Asia. Our results suggest that H5N1 viruses with pandemic potential have become endemic in the region and are not easily eradicable. These developments pose a threat to public and veterinary health in the region and potentially the world, and suggest that long-term control measures are required.

Facilitation of horizontal transfer of antimicrobial resistance by transformation of antibiotic-induced cell-wall-deficient bacteria

It is universally accepted that the use of antibiotics will lead to antimicrobial resistance. Traditionally, the explanation to this phenomenon was random mutation and horizontal gene transfer and amplification by selective pressure. Subsequently, a second mechanism of antibiotic-induced antimicrobial resistance acquisition was proposed, when Davies et al. discovered that genes encoding antimicrobial resistance are present in bacteria that produce antibiotics, and during the process of antibiotic purification from these antibiotic-producing organisms, remnants of the organisms' DNA that contain antibiotic resistance genes are also co-extracted, and can be recovered in antibiotic preparations. In addition to selective pressure and antimicrobial resistance genes in antibiotic preparations, we hypothesize the third mechanism by which administration of antibiotics leads to antimicrobial resistance. beta-Lactams and glycopeptides damage bacteria by inhibiting cell wall murein synthesis. During the process, cell-wall-deficient forms are generated before the bacteria die. These cell-wall-deficient forms have an increased ability to uptake DNA by transformation. It has been demonstrated that plasmids encoding antimicrobial resistance of Staphylococcus aureus can be transformed to Bacillus subtilis after the B. subtilis was treated with penicillin or lysostaphin, a chemical that damage the cell walls of some Gram-positive bacteria; and that short treatment of Escherichia coli with antibiotics disturbing bacterial cell wall synthesis rendered the cells capable of absorbing foreign DNA. Since bacteria occupying the same ecological niche, such as the lower gastrointestinal tract, is common, bacteria are often incubated with foreign DNA encoding resistance coming from the administration of antibiotics or other bacteria that undergone lysis unrelated to antibiotic-induced killing. As few as a single antibiotic resistant gene is taken up by the cell-wall-deficient form, it will develop into a resistant clone, despite most of the other bacteria are killed by the antibiotic. If the hypothesis is correct, one should reduce the use of antibiotics that perturb bacterial cell wall synthesis, such as beta-lactams, which is the largest group being manufactured, in both humans and animals, in order to reduce the acquisition of antibiotic resistance through this mechanism. In contrast to the old theory that antibiotics only provide selective pressures for the development of antimicrobial resistance, antibiotics by themselves are able to generate the whole chain of events towards the development of antimicrobial resistance. Antibiotics provide a source of antimicrobial resistance genes, facilitate the horizontal transfer of antimicrobial resistance genes through facilitating transformation, and provide selective pressures for amplification of the antimicrobial resistance genes. That is perhaps an important reason why antimicrobial resistance is so difficult to control. Further experiments should be performed to delineate which particular type of beta-lactam antibiotics are associated with increase in transformation efficiencies more than the others, so that we can select those less resistance generating beta-lactam for routine usage.

Characterization of a novel coronavirus responsible for severe acute respiratory syndrome

In February, a new avian H5N1/03 virus took two persons' lives in Hong Kong. After this incidence, a newly emerged disease has been identified, associated with pneumonia in infected patients. Here we report that a newly discovered coronoavirus (Cov) is responsible for this disease. In addition, the basic features, diagnosis and possible animal sources of Severe Acute Respiratory Syndrome (SARS) Cov are also discussed.

H5N1 influenza: a protean pandemic threat

Infection with avian influenza A virus of the H5N1 subtype (isolates A/HK/212/03 and A/HK/213/03) was fatal to one of two members of a family in southern China in 2003. This incident was preceded by lethal outbreaks of H5N1 influenza in waterfowl, which are the natural hosts of these viruses and, therefore, normally have asymptomatic infection. The hemagglutinin genes of the A/HK/212/03-like viruses isolated from humans and waterfowl share the lineage of the H5N1 viruses that caused the first known cases of human disease in Hong Kong in 1997, but their internal protein genes originated elsewhere. The hemagglutinin of the recent human isolates has undergone significant antigenic drift. Like the 1997 human H5N1 isolates, the 2003 human H5N1 isolates induced the overproduction of proinflammatory cytokines by primary human macrophages in vitro, whereas the precursor H5N1 viruses and other H5N1 reassortants isolated in 2001 did not. The acquisition by the viruses of characteristics that enhance virulence in humans and waterfowl and their potential for wider distribution by infected migrating birds are causes for renewed pandemic concern.

Severe acute respiratory syndrome: report of treatment and outcome after a major outbreak

BACKGROUND

The outcome is reported of a prospective uncontrolled study based on a stepwise treatment protocol during an outbreak of severe acute respiratory syndrome (SARS) in Hong Kong.

METHOD

One hundred and thirty eight patients were treated with broad spectrum antibiotics, a combination of ribavirin and low dose corticosteroid, and then intravenous high dose methylprednisolone according to responses. Sustained response to treatment was defined as (1) defervescence for > or =4 consecutive days, (2) resolution of lung consolidation by >25%, and (3) oxygen independence by the fourth day without fever. Patients with defervescence who achieved either criterion 2 or 3 were classified as partial responders. Patients who fell short of criteria 2 and 3 were non-responders.

RESULTS

Laboratory confirmation of SARS coronavirus infection was established in 132 (95.7%). None responded to antibiotics but 25 (18.1%) responded to ribavirin + low dose corticosteroid. Methylprednisolone was used in 107 patients, of whom 95 (88.8%) responded favourably. Evidence of haemolytic anaemia was observed in 49 (36%). A high level of C-reactive protein at presentation was the only independent predictor for use of methylprednisolone (odds ratio 2.18 per 10 mg/dl increase, 95% confidence interval 1.12 to 4.25, p = 0.02). Thirty seven patients (26.8%) required admission to the intensive care unit and 21 (15.2%) required invasive mechanical ventilation. There were 15 deaths (mortality rate 10.9%), most with significant co-morbidities, whereas 122 (88.4%) had been discharged home 4 months after the outbreak onset.

CONCLUSION

The use of high dose pulse methylprednisolone during the clinical course of a SARS outbreak was associated with clinical improvement, but randomised controlled trials are needed to ascertain its efficacy in this condition.

Reverse transcriptase PCR diagnostic assay for the coronavirus associated with severe acute respiratory syndrome

Recent outbreaks of severe acute respiratory syndrome (SARS) have spurred intense research efforts around the world to deal with the serious threat to health posed by this novel coronavirus. A rapid, reliable diagnostic assay is needed for monitoring the spread of the disease. Here we report a method for eliminating false-negative results and increasing test sensitivity, based on the hypothesis that the message encoded by the nucleocapsid (N) gene is the most abundant during viral infection. Nasopharyngeal aspirates and stool samples were obtained from suspected SARS patients with major clinical symptoms and a significant history of close contact with infected patients. Total RNAs were extracted in a 96-well format, together with pig kidney epithelial (PK-15) cells as an internal control for extraction efficiency. PCR inhibitors were removed by ethanol precipitation, and a PCR for the pig beta-actin gene was used as a positive control for all clinical samples. Samples were analyzed by a reverse transcriptase PCR assay. Northern blot analysis was performed to demonstrate differences in subgenomic transcripts of the virus, and a real-time quantitative PCR was employed to compare the sensitivities of two loci (1b and N). The detection rate of the assay reached 44.4% on day 9 after the onset of the disease. The diagnostic PCR amplifying the N gene gave an average of a 26.0% (6.3 to 60.0%) stronger intensity signal than that for the 1b gene. In conclusion, the nucleocapsid gene represents an additional sensitive molecular marker for the diagnosis of the SARS coronavirus and can be further adapted for use in a high-throughput platform assay.

Toxic scarlet fever complicating cellulitis: early clinical diagnosis is crucial to prevent a fatal outcome

We describe a case of toxic scarlet fever in a healthy adult with streptococcal cellulitis of the right elbow as a result of skin abrasion. The clinical picture mimicked that of drug eruption after treatment of cellulitis with antibiotics. Among the five cases of scarlet fever complicating cellulitis, including the present one, reported in the English literature, four had severe systemic complications and two died. As a result of re-emergence of invasive streptococcal infections, clinicians should be aware of the differential diagnosis of scarlet fever in patients presenting with cellulitis and skin rash. Early clinical diagnosis is crucial to exclude drug eruptions, prompt initiation of antibiotic treatment, and prevention of the potentially fatal outcome.

Clinical evaluation of the polymerase chain reaction for the rapid diagnosis of tuberculosis

AIMS

Use of the polymerase chain reaction for the detection of Mycobacterium tuberculosis (TB PCR) as a basis for making clinical decisions on the initiation of antituberculosis treatment was studied.

METHODS

A retrospective study involving a cohort of 155 patients being investigated for tuberculosis in an infectious disease consultation service was undertaken. TB PCR was performed on pulmonary and extrapulmonary specimens from these patients. The sensitivity of TB PCR was analysed.

RESULTS

Of the 155 patients, 144 fitted the clinical diagnosis of tuberculosis, and 112 of them were culture positive for M tuberculosis. Sixty (58.3%) patients with clinical features suggestive of tuberculosis received antituberculosis treatment based on positive TB PCR alone. Of 224 clinical specimens (138 pulmonary and 86 extrapulmonary) sent for TB PCR, 148 (99 pulmonary and 49 extrapulmonary) were positive in 117 patients. Of the 690 clinical specimens sent for culture, 279 were positive for M tuberculosis in 112 patients. The diagnostic sensitivity of TB PCR was 75.9% (85 of 112) and 81.3% (117 of 144) in patients with culture confirmed and clinically diagnosed tuberculosis, respectively. Using culture as the gold standard, the overall sensitivity of TB PCR was 78.3%, and for pulmonary and extrapulmonary specimens it was 82.3% and 72.0%, respectively.

CONCLUSIONS

TB PCR is a rapid and reliable test in the diagnosis and management of tuberculosis.

Role of lopinavir/ritonavir in the treatment of SARS: initial virological and clinical findings

BACKGROUND

The clinical response of patients with severe acute respiratory syndrome (SARS) to a combination of lopinavir/ritonavir and ribavirin was examined after establishing the in vitro antiviral susceptibility of the SARS associated coronavirus to a panel of antiviral agents.

METHODS

The in vitro susceptibility of the prototype of SARS associated coronavirus to a panel of nucleoside analogues and protease inhibitors currently licensed for clinical use was studied. Forty one patients with SARS followed for 3 weeks were treated with a combination of lopinavir/ritonavir and ribavirin. The clinical progress and virological outcomes were monitored and compared with 111 patients treated with ribavirin only who served as historical controls.

RESULTS

In vitro antiviral activity against SARS associated coronavirus was demonstrated for lopinavir and ribavirin at concentrations of 4 micro g/ml and 50 micro g/ml, respectively, only at 48 hours. The adverse clinical outcome (ARDS or death) was significantly lower in the treatment group than in the historical controls (2.4% v 28.8%, p<0.001) at day 21 after the onset of symptoms. The adverse outcome remained significantly lower in the treatment group than in the controls-both those diagnosed early (p<0.001) and those diagnosed later in the course of the epidemic (p = 0.002)-but there was no significant difference in adverse outcome rates between the two time periods (p = 0.548). No time related difference in outcome was observed in the control groups. A reduction in steroid usage and nosocomial infections was seen in patients initially treated with lopinavir/ritonavir, and these patients had a decreasing viral load and rising peripheral lymphocyte count. Multivariate analysis showed that age, hepatitis B carrier status, and lack of treatment with this antiviral combination were independent predictors of an adverse outcome. Lopinavir/ritonavir treatment was associated with a better outcome even when adjusted for baseline lactate dehydrogenase level.

CONCLUSIONS

The apparent favourable clinical response with lopinavir/ritonavir and ribavirin supports further randomised placebo controlled trials in patients with SARS.

Re-emergence of fatal human influenza A subtype H5N1 disease

Human disease associated with influenza A subtype H5N1 re-emerged in January, 2003, for the first time since an outbreak in Hong Kong in 1997. Patients with H5N1 disease had unusually high serum concentrations of chemokines (eg, interferon induced protein-10 [IP-10] and monokine induced by interferon gamma [MIG]). Taken together with a previous report that H5N1 influenza viruses induce large amounts of proinflammatory cytokines from macrophage cultures in vitro, our findings suggest that cytokine dysfunction contributes to the pathogenesis of H5N1 disease. Development of vaccines against influenza A (H5N1) virus should be made a priority.

Evaluation of reverse transcription-PCR assays for rapid diagnosis of severe acute respiratory syndrome associated with a novel coronavirus

The reverse transcription (RT)-PCR protocols of two World Health Organization (WHO) severe acute respiratory syndrome (SARS) network laboratories (WHO SARS network laboratories at The University of Hong Kong [WHO-HKU] and at the Bernhard-Nocht Institute in Hamburg, Germany [WHO-Hamburg]) were evaluated for rapid diagnosis of a novel coronavirus (CoV) associated with SARS in Hong Kong. A total of 303 clinical specimens were collected from 163 patients suspected to have SARS. The end point of both WHO-HKU and WHO-Hamburg RT-PCR assays was determined to be 0.1 50% tissue culture infective dose. Using seroconversion to CoV as the "gold standard" for SARS CoV diagnosis, WHO-HKU and WHO-Hamburg RT-PCR assays exhibited diagnostic sensitivities of 61 and 68% (nasopharyngeal aspirate specimens), 65 and 72% (throat swab specimens), 50 and 54% (urine specimens), and 58 and 63% (stool specimens), respectively, with an overall specificity of 100%. For patients confirmed to have SARS CoV and from whom two or more respiratory specimens were collected, testing the second specimen increased the sensitivity from 64 and 71% to 75 and 79% for the WHO-HKU and WHO-Hamburg RT-PCR assays, respectively. Testing more than one respiratory specimen will maximize the sensitivity of PCR assays for SARS CoV.

Molecular epidemiology of the novel coronavirus that causes severe acute respiratory syndrome

BACKGROUND

Severe acute respiratory syndrome (SARS) is a newly emerged disease caused by a novel coronavirus (SARS-CoV), which spread globally in early 2003, affecting over 30 countries. We have used molecular epidemiology to define the patterns of spread of the virus in Hong Kong and beyond.

METHODS

The case definition of SARS was based on that recommended by WHO. We genetically sequenced the gene for the S1 unit of the viral spike protein of viruses from patients with SARS in Hong Kong (138) and Guangdong (three) in February to April, 2003. We undertook phylogenetic comparisons with 27 other sequences available from public databases (Genbank).

FINDINGS

Most of the Hong Kong viruses (139/142), including those from a large outbreak in an apartment block, clustered closely together with the isolate from a single index case (HKU-33) who came from Guangdong to Hong Kong in late February. Three other isolates were genetically distinct from HKU-33 in Hong Kong during February, but none of these contributed substantially to the subsequent local outbreak. Viruses identified in Guangdong and Beijing were genetically more diverse.

INTERPRETATION

The molecular epidemiological evidence suggests that most SARS-CoV from the outbreak in Hong Kong, as well as the viruses from Canada, Vietnam, and Singapore, are genetically closely linked. Three viruses found in Hong Kong in February were phylogenetically distinct from the major cluster, which suggests that several introductions of the virus had occurred, but that only one was associated with the subsequent outbreak in Hong Kong, which in turn spread globally.

Treatment of severe acute respiratory syndrome with lopinavir/ritonavir: a multicentre retrospective matched cohort study

OBJECTIVES

To investigate the possible benefits and adverse effects of the addition of lopinavir/ritonavir to a standard treatment protocol for the treatment of severe acute respiratory syndrome.

DESIGN

Retrospective matched cohort study.

SETTING

Four acute regional hospitals in Hong Kong.

PATIENTS AND METHODS

Seventy-five patients with severe acute respiratory syndrome treated with lopinavir/ritonavir in addition to a standard treatment protocol adopted by the Hospital Authority were matched with controls retrieved from the Hospital Authority severe acute respiratory syndrome central database. Matching was done with respect to age, sex, the presence of co-morbidities, lactate dehydrogenase level and the use of pulse steroid therapy. The 75 patients treated with lopinavir/ritonavir were divided into two subgroups for analysis: lopinavir/ritonavir as initial treatment, and lopinavir/ritonavir as rescue therapy. These groups were compared with matched cohorts of 634 and 343 patients, respectively. Outcomes including overall death rate, oxygen desaturation, intubation rate, and use of pulse methylprednisolone were reviewed.

RESULTS

The addition of lopinavir/ritonavir as initial treatment was associated with a reduction in the overall death rate (2.3%) and intubation rate (0%), when compared with a matched cohort who received standard treatment (15.6% and 11.0% respectively, P<0.05) and a lower rate of use of methylprednisolone at a lower mean dose. The subgroup who had received lopinavir/ritonavir as rescue therapy, showed no difference in overall death rate and rates of oxygen desaturation and intubation compared with the matched cohort, and received a higher mean dose of methylprednisolone.

CONCLUSION

The addition of lopinavir/ritonavir to a standard treatment protocol as an initial treatment for severe acute respiratory syndrome appeared to be associated with improved clinical outcome. A randomised double-blind placebo-controlled trial is recommended during future epidemics to further evaluate this treatment.