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The etiology of bloodstream infections in febrile patients remain poorly characterized in Nepal. A retrospective study of febrile patients presenting to Dhulikhel Hospital Kathmandu University Teaching Hospital from July 2002 to June 2004 was performed to evaluate the etiology of bloodstream infections and the drug sensitivity patterns of cultured organisms. The medical and laboratory records of all febrile patients with an axillary temperature > or = 38 degrees C who had a blood culture taken (n = 1,774) were retrieved and analyzed. Of these, 122 (6.9%) patients had positive blood cultures, of which 40.1% were age 11 to 20 years. The male to female ratio was 1.7:1. Antibiotics had been taken prior to hospital presentation by 39 (32%) patients. Salmonella enterica serovar Typhi and serovar Paratyphi A were isolated in 50 (41.0%) and 13 (10.7%) cases, respectively. All S. Typhi and S. Paratyphi isolates were susceptible to ceftriaxone, while susceptibility to ciprofloxacin and chloramphenicol was recorded in 94.8% and 94.5% of cases, respectively. Cephalexin and amoxicillin had the lowest rates of susceptibility (64.2% and 54.1%, respectively). Salmonella spp were usually sensitive to chloramphenicol. These findings provide clinicians in this region of Nepal with a better understanding of the spectrum of pathogens causing bloodstream infections and will help guide empiric antibiotic choice.

Objective: Yield of blood culture in clinically suspected cases of typhoid fever is low, whereas indirect serological diagnostic tests are unreliable. Hence, polymerase chain reaction (PCR)-based detection of Salmonella enterica Serovar typhi was used as an aid for diagnosis of typhoid fever in addition to other diagnostic tests. Two periurban communities in Karachi were selected for an epidemiological study of typhoid fever. The aim of the study was to assess whether PCR increased the detection rate of typhoid fever in children in the community., Material and Methods: Children aged 2 to 14 years presenting with fever lasting for three or more days were selected. PCR using Hashimoto's protocol based on ViaB gene sequence was used in addition to blood culture and other serological tests., Results: Of the 214 children included in the study, blood culture was found positive for S. enterica S. typhi in 26 (12.4%) cases, whereas 24 children (11.7%) were diagnosed as suffering from typhoid fever when the PCR-based method was used. Both tests were positive in only 10 (4.9%) children. The number of children found positive for either test was 40. PCR increased the rate of detection of typhoid fever by 51%., Conclusion: The sensitivity, specificity, +ve and -ve predictive values of PCR in this study were 40%, 93%, 45% and 92%, respectively.

Blood, stool and urine samples were collected from 100 patients diagnosed as having typhoid in 5 hospitals in Akwa Ibom State and analyzed for the presence of Salmonella species and other bacteria. Of the 100 blood samples screened, 55 (55%) were positive with the Widal test and 39 (39%) were positive on blood culture. Thirteen (14.1%) out of 92 urine samples were positive for bacterial growth, while 22 (26.8%) of the stool cultures were positive out of the 82 samples screened. Those within the age range 11-20 years old were infected most frequently (33%), followed by the age range 21-30 (19%) and 41-50 (18%) years old. Those in the age range of 0-2 years old (4%) were least infected. Female subjects were more infected than males. The commonest organisms isolated from the blood samples were Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, Streptococcus faecalis, Salmonella paratyphi and Salmonella typhi. S. aureus, S. epidermidis, E. coli, K. aerogenes, S. faecalis, Proteus mirabilis and P. aeruginosa were isolated from urine, while those isolated from stool were S. aureus, E. coli, S. typhi, S. paratyphi, Shigella sp, K. pneumoniae, P. vulgaris, P. aeruginosa and Vibrio cholerae 01. The isolates were sensitive to peflacine, ceftazidine, ciprofloxacin, ceftriaxone, cefotaxime and chloramphenicol. These antibiotics are recommended as the drugs of choice in therapy. The results suggest the existence of symptomless carriers of enteric fever bacilli in the state. This is worrisome, since some of the S. typhi isolates exhibited multiple resistance to commonly used antibiotics.

Objective: The aim of this study was to determine the prevalence of Salmonella enterica serovar typhi in patients with pyrexia of unknown origin (PUO), and antimicrobial resistance in strains isolated from patients with S. typhi in Lagos, Nigeria., Study Design: In total, 103 patients were included in this study, subdivided into two categories. Category A comprised 74 patients presenting with PUO, and Category B comprised 29 patients harbouring S. typhi who did not respond to initial treatment., Methods: Blood samples were cultured for bacterial isolates and identified by standard procedures. Susceptibility testing was performed according to the National Committee for Clinical Laboratory Standards. Plasmid DNA extraction was performed using the alkaline lysis method with Escherichia coli v517 used as the standard. Conjugation and transformation experiments were performed using standard methods. For the latter, E. coli K12 HB 101 (ara-14, galK2, hsd 520, lacyl, leu, mtl-1, Pro A2, rec A13, rps L20, sup E44, thii xyl-5) was used as the recipient and plasmid PBR 322 was used as the positive control., Results: The prevalence of S. typhi in PUO was 16.2% (12/74). In all, 25 of 41 (61.0%) cases were multidrug resistant (MDR) with phenotypic-resistant patterns: ACoCT, ACTCeS, ACTCoCe and ACTS were commonly encountered among the strains. Interestingly, four of the strains harbouring similar plasmid DNA were isolated from patients with hepatosplenomegaly, and a strain harbouring a large transferable plasmid of 81.2MDa was isolated from a psychosis patient., Conclusions: Our study confirmed the circulation of MDR S. typhi in Lagos, Nigeria. Periodic review of antibiotics used in hospitals is essential as the efficacies of chloramphenicol, ampicillin and cotrimoxazole are now doubtful. Ciprofloxacin and ofloxacin are effective drugs for treatment of typhoid fever, but with current trends of drug abuse in Nigeria, resistance is likely to develop. These results, therefore, provide an early warning signal for the prudent use of fluoroquinolone antimicrobials to preserve their usefulness.

The paper looks at the usefulness of the Widal agglutination test in the context of variable normal antibody titres in two different populations in Kenya, and in comparison to the blood culture method of diagnosis. It presents a prospective case-control study. We examined 846 blood cultures and an equal number of serum samples, and 782 stools from adults who presented at two study sites; Kenyatta National Hospital and one hospital and 3 clinics in Embu District, with symptoms similar to typhoid. Examined also were 360 serum samples and stools from adults who were apparently healthy (controls) who sought routine medical examination at the study sites. From blood cultures, isolation rates for typhoid for Embu (3% ) and Nairobi (2.2%) were not significantly different (p>0.01). In addition the control population from the two study sites did not show any significant background O antibody titre levels characteristic of typhoid endemic areas. All the 7 commonly available Widal test kits including Murex, Europath, Biotech, Humatex, Biosystems, Microsystems and Typhex, that were evaluated for efficacy were equally specific in diagnosis of typhoid by Widal agglutination methods. However, there were minor differences in the sensitivities of the kits. The Widal test method gave a lower sensitivity (81.3%) than specificity (93%) when compared to the culture of blood for diagnosis of typhoid. Going by the reports of typhoid outbreaks in Embu and Nairobi (ca. 20-25% reported prevalence) we conclude that there has been over-reporting probably due to poor methodologies of performing the Widal test. We recommend adequate clinical examination in suspected cases of typhoid in addition to proper Widal in order to improve typhoid diagnosis. Newer improved methods that are more specific and sensitive than the Widal test need to be evaluated in improving laboratory diagnosis of typhoid.

The emergence of reduced susceptibility to ciprofloxacin among Salmonella enterica serotype Typhi and serotype Paratyphi A leading to clinical failure of treatment poses a great therapeutic challenge. The mechanism of fluoroquinolone resistance in clinical isolates of S. Typhi and S. Paratyphi A is not very well documented. The present study was carried out with the objective of molecular characterization of reduced quinolone susceptibility amongst the strains of S. Typhi and S. Paratyphi A isolated from the patients with enteric fever during January, 2000, to April, 2003, in a North Indian hospital. A total of 422 culture-positive cases of enteric fever were reported to the hospital during the period of study, of which S. Typhi was isolated from 350 cases and S. Paratyphi A from 72 cases. The antimicrobial susceptibility of these strains was determined by disk diffusion and agar dilution method according to NCCLS guidelines, and E-test method. A total of 140 randomly selected strains, isolated during the years 1993-1999, that were available from the laboratory stocks were also studied to compare with the present strains. To study the quinolone susceptibility, the strains were divided into nalidixic acid sensitive (NAS), nalidixic acid intermediate resistant, (NAI) and nalidixic acid resistant (NAR) on the basis of susceptibility to nalidixic acid. Clinical history was available from 174 patients, of which 93 needed hospitalization due to severe disease. Of these, 82 patients were infected with NAR strains and 22 patients had a documented evidence of clinical failure to ciprofloxacin therapy. The patients infected with NAR strains were younger and had a significantly longer duration of fever (p value < 0.05) than those infected with NAS strains. It was observed that the proportion of NAR strains increased gradually over the years. These strains had a significantly higher range of MIC of ciprofloxacin (0.023-1.0 microg/ml) as compared to the NAS strains (0.002-0.125 microg/ml) (p value < 0.05). The sequencing of quinolone resistance determining region (QRDR) of the gyrA gene showed the presence of mutation at either Ser 83 or at Asp 87 in all the NAR and NAI strains. None of the NAS strains had a mutation, suggesting that the gyrA gene mutation is sufficient to confer resistance to nalidixic acid and reduced susceptibility to ciprofloxacin. This mutation, although phenotypically expressed as decreased susceptibility to ciprofloxacin, goes undetected by the disk diffusion method using the present NCCLS guidelines. Hence, it can increase morbidity and mortality due to delay in appropriate antibiotic treatment.

A laboratory study comparing the Widal slide agglutination test using local antigens produced by Mekar Jaya Diagnostica (SAT-MJD) with imported antigens (Murex, Abbott) was carried out on 55 sera of typhoid fever patients with positive blood culture and 56 sera of non-typhoid febrile patients. The SAT-MJD antigens consisted of a mixture of 5 different phage-types of S. typhi dominantly found in Indonesia. This study revealed the following results: the diagnostic sensitivity of local and imported antigens was 83.93%, the diagnostic specificity of local antigens was higher than the imported antigens ie 82.14% compared with 64.28%, the diagnostic efficiency of local antigens was 82.88% compared with 73.87% of the imported antigens. The diagnostic positive and negative predictive values of the local antigens were 80.70% and 83.63%, respectively. The imported antigen revealed diagnostic positive and negative predictive values of 69.69% and 80%, respectively. The diagnostic specificity and efficiency of local antigens were significantly different (p < 0.02 and p < 0.05) from the imported antigens. The local antigens have some advantages. There was no variation in within-run and between-day test, compared with a 6.6% variation shown by the imported antigen. The test results obtained 5 minutes after mixing the serum with antigens reduced the possibility of false-positive and false-negative results. The cost of local antigens is lower than the imported antigens. Based on these data, the Widal SAT-MJD has a reliable diagnostic value and can be used in small laboratories, such as primary health centers (Puskesmas).

Background: Recently there has been an increase in the clinically diagnosed typhoid fever in various parts of Nigeria with subsequent increase in public fear of possible epidemics of the disease. In this study the accuracy of clinically diagnosed typhoid fever were investigated., Methods: Blood and stool specimens from 260 patients clinically diagnosed typhoid fever were investigated using Widal test and bacteriological culture methods respectively., Results: One hundred and thirty-four (51.5%) of the cases investigated were positive and that there was a significant difference (P < 0.05) between the clinically diagnosed and bacteriologically confirmed typhoid fever cases. Causative organisms were Salmonella typhi 46 (34.3%); S paratyphi B 34 (25.4%); S paratyphi A 24 (17.9%); S paratyphi C 20 (14.9%); other Salmonella spp 10 (7.5%). Young adults and males were predominantely affected., Conclusion: Most of the clinically diagnosed typhoid cases were misdiagnosis and the hue and cry by the general public on the epidemic of typhoid fever could not be justified. It is recommended that careful detailed history taking, meticulous clinical examination and prompt bacteriological culturing of specimens from suspected typhoid cases will improve the accuracy of clinically diagnosed typhoid fever.

The aim of the study is to determine the baseline antibody titres to Salmonella typhi/paratyphi in healthy individuals with a view to establishing the significant titre for Widal agglutination test in Ile-Ife, Western Nigeria. Three hundred and ten healthy volunteers were admitted into the study and forty-eight clinically diagnosed and culture positive cases of Enteric fever were used as purposeful controls. Widal test was performed on each serum. Slide agglutination test was first done, then positive samples were further subjected to tube agglutination for quantitative titration. Of the 310 healthy volunteers, 274 (97.2%) had reciprocal antibody titre of < or = 80 to O antigen and 265 (95.0%) had reciprocal antibody titre of < or = 80 to H. antigen of S. typhi. On the other hand, in 48 control cases, 43 (89.6%) had reciprocal antibody titre of > or = 160 to O antigen and 38 (78.2%) had reciprocal titre of > or = 160 to H. antigen. The sensitivity and specificity of the test were 89.9% and 94.2% for O antibody, and 79.2% and 92.3% for H. antibody respectively. The baseline titre to S. typhi/paratyphi for both O & H antibody is 1:80 whilst the significant titre for O & H antibodies is 1:160 and above in Ile-Ife, Nigeria.

Using the polymerase chain reaction (PCR) assay, we developed a rapid diagnosis method for Salmonella typhi infection in blood specimens from patients with typhoid fever. Primers were designed from the flagellin gene sequence, which would give an amplification product of 367 base pairs. In this study, the specificity of the assay, with no amplification, was seen for the other Salmonella strains with the flagellin gene, and not for non- Salmonella bacteria. For the sensitivity test, the protocol described allowed the detection of two to three copies of the Salmonella typhi genome, as determined by serial dilution of genomic DNA from Salmonella typhi. With the PCR technique, genomic DNA of Salmonella typhi was detected in 46 of 73 blood samples collected from patients with clinically suspected typhoid fever who had fever within 3 days of admission to the General Hospital, Makassar, South Sulawesi, Indonesia, and who had had no prior antibiotic treatment. The PCR results (63% positive cases) were compared with those of blood culture (13.7% positive cases) and the Widal test (35.6% positive cases), using the same samples from each of the 73 patients admitted to the General Hospital in Makassar. The time taken for PCR analysis of each sample was less than 12 h, compared with 3 to 5 days for blood or clot culture. The PCR with one pair of primers can be used as a novel, rapid diagnostic method for typhoid fever, particularly when results of standard culture assays are negative.

To measure the incidence of typhoid fever and other febrile illnesses in Bilbeis District, Egypt, we conducted a household survey to determine patterns of health seeking among persons with fever. Then we established surveillance for 4 months among a representative sample of health providers who saw febrile patients. Health providers collected epidemiologic information and blood (for culture and serologic testing) from eligible patients. After adjusting for the provider sampling scheme, test sensitivity, and seasonality, we estimated that the incidence of typhoid fever was 13/100,000 persons per year, and the incidence of brucellosis was 18/100,000 persons per year in the district. This surveillance tool could have wide applications for surveillance for febrile illness in developing countries.

Although the efficacy of ceftriaxone in typhoid fever is well documented, the precise duration of ceftriaxone therapy in children with typhoid fever is not established and varies from 3 to 14 days in the literature. In a prospective, randomized study ceftriaxone was compared with chloramphenicol for treatment of 72 children who had bacteriologically confirmed typhoid fever. Ceftriaxone was given at a dose of 75 mg/kg per day (maximally 2 g/day) intravenously, in two doses until defervescence and continued 5 days after that time. Chloramphenicol was given at a dose of 75 mg/kg per day (maximally 2 g/day) in four doses for 14 days. Mean defervescence time was in 5.4 days in the ceftriaxone group and 4.2 days in the chloramphenicol group (P=0.04). Clinical cure without complications was achieved in all patients in both groups. No patient relapsed in the ceftriaxone group, and four patients relapsed in the chloramphenicol group (P=0.048). The overall results of this study suggest that a flexible-duration of ceftriaxone therapy given until defervescence time, followed by an additional 5 days of therapy is a reasonable alternative to conventional 14-day chloramphenicol treatment in children with typhoid fever.

Background: Hemolytic uremic syndrome (HUS) has been associated with typhoid fever caused by Salmonella typhi. The pathogenesis of HUS in the context of S typhi infection is not known. The authors report on a patient with typhoid fever in whom HUS and myocarditis developed during the course of his illness and in whom there was no evidence of a Shiga-toxin (Stx)-producing organism., Methods: Antibodies directed against the Escherichia coli O157:H7 and S typhi lipopolysaccharide (LPS) were sought in the serum sample taken during the acute phase using line-blot immunoassays. Polymerase chain reaction was performed to detect the presence of stx1 and stx2 genes in the patient's S typhi isolate., Results: There was no evidence for immunoglobulin (Ig) M and IgA against the LPS of E coli O157:H7, whereas anti-S typhi LPS IgM and IgA were strongly positive. In the polymerase chain reaction, DNA from the Stx-producing E coli controls yielded stx1 and stx2 fragments of the expected sizes on agarose gel electrophoresis, whereas no stx1 and stx2 fragments were obtained from the S typhi isolate. The S typhi did, however, yield a band when amplified with primers specific for viaB, an S typhi gene., Conclusion: S typhi may be responsible for some cases of HUS, and the inciting toxin may not be Stx., (Copyright 2003 by the National Kidney Foundation, Inc.)

Objectives: To evaluate the diagnostic specificity of modified Widal for recent infection in comparison with conventional Widal test., Method: Modified widal test was simultaneously done along with conventional Widal test in serum samples obtained from 50 bacteriologically positive cases of Salmonella typhi infection as well as 50 healthy individuals., Results: A four-fold difference in the titres was noticed in the 50 sera of the test group and no charge in the titres of the control group. The early rising O antibodies which are predominantly IgM in nature. These are due to recent infection and are inactivated by 2-mercaptoethanol. On the other hand H is a mixture of IgG and IgM hence IgM portion gets inactivated giving rise to fall in titre. By inactivating IgM antibodies in modified Widal test, the agglutination would be brought about only by specific IgG while in the conventional Widal test agglutination is due to specific IgG and IgM. The difference in the titres indicates specific IgM class of antibodies which is the hallmark of recent infection., Conclusion: If conventional Widal test and modified Widal test are simultaneously done, one can be definite about the diagnosis of enteric fever.

In typhoid epidemy in Tadjikistan we studied hemograms obtained in 200 patients and 100 healthy controls matched by age. Though hematological shifts are considered to be typical of typhoid, most of the patients had no hematological disorders despite their severe condition. Hemograms were normal in half of the patients at the height of typhoid while other patients often (40-43%) had accelerated ESR, uneosinophilia and left shift of immature neutrophils.

Culture and serology were performed on blood and serum samples collected at or shortly after admission from 473 patients presented with suspected clinical typhoid. Clinical symptoms at first presentation including confusion, hepatomegaly, splenomegaly, abdominal pain, anemia, and gastrointestinal bleeding were non-specific as they were observed even more often in non-typhoid patients. Culture confirmed the diagnosis in 65.3% of the patients with typhoid fever as the final diagnosis. The sensitivity (58%) and specificity (98.1%) of a rapid dipstick assay for the detection of S. typhi-specific immunoglobulin M were somewhat lower than those of culture but higher than those of the Widal test. The dipstick assay thus may well be used in the serodiagnosis of typhoid in situation where culture facilities are not available. Combination of test results of dipstick and culture improved sensitivity to 82.5%. In laboratories that perform blood culture the dipstick assay may be used as a rapid screening tests to facilitate a rapid diagnosis. Sensitivity of the dipstick assay strongly increased with duration of illness and was higher for culture positive than for culture negative patients. Duration of illness, and different pathogen and host factors including dose of infection, pathogenicity and antigenicity, and prior antibiotic use are likely to influence the immune response, therefore the result of the dipstick assay. Duration of illness and presence of S. typhi in the blood are major factors that determine severity of disease.

Background & Objectives: As typhoid fever is endemic in India, there is a continuing search for a simple test which can be carried out in small laboratories for an early and rapid diagnosis. We have evaluated the Typhidot test for this purpose., Methods: The Typhidot test was carried out on coded sera according to the manufacturer's instructions. The test was performed on 30 Widal positive sera, 30 sera from blood culture positive patients, 60 Widal negative sera and 30 samples from patients whose blood culture grew Gram negative bacilli (GNB) other than Salmonella Typhi., Results: Typhidot test was positive for both IgG and IgM in 39 samples, IgM alone in 24 and IgG alone in 2. Of the 30 culture positive samples, 27 were positive by Typhidot. The Typhidot test gave a sensitivity of 100 per cent and specificity of 80 per cent when bacteraemic patients were analysed., Interpretation & Conclusion: The Typhidot is easy to perform, and requires no special equipment or training of staff for interpretation of results. It will be a useful complementary test to blood culture and the Widal test in the diagnosis of typhoid fever.

The ex vivo cytokine response to lipopolysaccharide (LPS) of whole blood from patients with typhoid fever was investigated. Tumor necrosis factor (TNF)-alpha release by LPS-stimulated blood was found to be lower during acute typhoid fever than after a course of antimicrobial therapy (P

An outbreak of typhoid fever in Florida involving at least 16 persons during the winter of 1998-99 was investigated using case-control, environmental, and laboratory methods. The genomic profiles of Salmonella serovar Typhi (Salmonella Typhi) isolates from the 15 confirmed case subjects were identical. Consumption of fruit shakes made with frozen mamey, a tropical fruit, was significantly associated with illness (matched odds ratio, 7.6; 95% confidence interval, 1.4-81.4). Laboratory testing showed that the fruit was heavily contaminated with fecal coliforms; no Salmonella Typhi was isolated. The frozen mamey was prepared in plants in Guatemala and Honduras. No further cases occurred after the frozen product was recalled. As our nation's food sources become increasingly globalized, the risk of outbreaks of exotic diseases linked to contaminated imported food will increase. This outbreak highlights the need for new approaches to ensure the safety of our food supply.

Typhoid is a global problem. Conventional diagnostic methods have limitations. The Widal test gives a high proportion of false positive results, and indiscriminate use of antibiotics has reduced the utility of blood culture. Consequently, these procedures are inadequate for diagnosing suspected cases of typhoid that do not present clear-cut symptoms. We previously showed that PCR-based diagnosis of typhoid targeting the flagellin gene has unparalleled specificity. We assessed the utility of this method for diagnosis of problematic cases of typhoid. A comparative study of PCR, blood culture, and Widal test was carried out on 55 cases of suspected typhoid with fever for 3-30 days and possessing an ambiguous clinical picture. A control group comprised of 20 healthy persons was also included. The respective positive results by PCR, blood culture, and Widal test for these groups were 58.2 and 0%, 14.5 and 0%, and 52.7 and 45%. Sensitivity of PCR as compared with that of blood culture was significantly better. We concluded that PCR is much superior to conventional methods and, due to its high sensitivity and specificity, can be of great use for rapid and definitive diagnosis of problematic cases of typhoid.

Background: Enteric fever remains a major cause of fever in travelers. We evaluated new trends in enteric fever., Methods: We reviewed the epidemiological, clinical, biological, bacteriological data, and outcome of all cases of typhoid and paratyphoid fever seen in our department over the last decade. The inclusion criteria were the presence of signs compatible with enteric fever and isolation of Salmonella typhi or Salmonella paratyphi A, B, or C from blood or stool cultures or any other site., Results: Among the 41 patients, 38 (93%) had travel-associated enteric fever. The main geographic source of contamination was the Indian subcontinent. One patient had been vaccinated with parenteral Vi vaccine 1 year previously. Fever and headaches were the only signs which were present in more than 80% of patients. The Widal test at inclusion was positive in 27%, and a second serological test was found to be positive in 50% of evaluated cases. Blood cultures and stool cultures were positive in 34 cases and 10 cases, respectively. Salmonellae spp were isolated in both hemocultures and stool cultures in 4 cases and in urine in 1 case. Two strains of S. typhi were resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole. One strain of S. typhi and one of S. paratyphi B were nalidixic acid resistant. All evaluable patients were cured with the exception of 2 patients (1 failure, 1 relapse). We observed 3 toxic reactions. No patients died., Conclusion: The diagnosis and outcome of enteric fever are hampered by the lack of specificity of clinical and biological signs, the increasing rates of antimicrobial resistance, and the occurrence of toxic reactions during treatment.

Epidemiological features of blood culture confirmed typhoid fever and antibiotic sensitivity of isolated Salmonella typhi strains were investigated in Bohol Province in Central Philippines from where no earlier information of these was avialable. Typhoid fever is endemic elsewhere in the Philippines (eg Metropolitan Manila and surroundings) where also multidrug resistant S. typhi strains have been detected. A laboratory for surveillance of invasive bacterial infections was established in a tertiary care government hospital, in Bohol, Central Philippines, in 1994. Patients with suspected typhoid fever or other serious infection were managed and blood cultures from them were taken according to clinicians' judgment. Blood cultures were processed and the isolated bacteria identified using generally accepted methods. S. typhi and other Salmonella isolates were identified using commercial antisera. Patient data were collected from hospital records. Of a total of 4,699 blood cultures done during a period of 3 3/4 years, 1,530 (32%) were requested for suspected typhoid fever. S. typhi was the most common pathogen isolated from 422 patients (8.9%), followed by S. paratyphi A from 55 patients (1%). Most patients were young adults (43%) and school age children (28%). Male:female ratio was 1.5:1. Among the 422 patients, there were 9 (2%) deaths due to typhoid fever, all with complications. All S. typhi isolates were sensitive to chloramphenicol, cotrimoxazole, and ampicillin. Our observation on blood culture confirmed typhoid fever demonstrates its importance as a major infectious disease in Bohol and gives a sound basis for treatment of typhoid patients and for further clinical and epidemiologic studies of typhoid fever and for following antibiotic sensitivity of S. typhi in Bohol and elsewhere in the Philippines.

Typhoid fever is still an important public health problem in many developing countries especially in tropical parts of the world, as in Indonesia. This problem opens the way for a further study with the aim of finding an alternative serological test with a high degree of reliability for the detection of typhoid fever. Given the above mentioned purpose, a study on the reliability of a laboratory test, the dot-enzyme-immunoassay outer membrane protein (DOT-EIA-OMP) was conducted comprising sera from 207 subjects (44 adult typhoid patients, 43 adult nontyphoid patients and sera from 120 adult healthy individuals serving as controls. The result of the study revealed that the diagnostic sensitivity of the DOT-EIA-OMP test for the detection of typhoid fever can be classified as high (93.16%), the specificity as moderate (76.74%), the efficiency (accuracy), positive predictive value and negative predictive value as high (85.06%, 80.39% and 91.66% respectively). The within run and between days reproducibility of this test was very high (CV=0%). Analysis of data obtained indicated that the DOT-EIA-OMP test was a reliable screening test for the establishment of the diagnosis of typhoid fever in health centers with simple laboratory facilities. The application of this test has to be more contemplated in countries where the cost of laboratory test is a problem.

To investigate the role of serum C-reactive protein (CRP) in the diagnosis of typhoid fever, we studied 227 febrile Malaysian children hospitalized during a 12-month period. The children were: culture-positive for Salmonella typhi (Group 1; n = 108); culture-negative but with typical clinical features of typhoid fever (Group 2; n = 60); or had non-typhoidal illness (Group 3; n = 59). Group 1 children had the highest serum CRP concentrations (geometric mean [SD range]; 43 [12-150] mg/l vs. 26 [8-85] mg/l in Group 2 and 21 [4-110] mg/l in Group 3; p < 0.001). In regression analysis, age, patient group and fever duration were independently associated with serum CRP (p < 0.05) but gender was not. In Group 1 patients, there was a significant positive association between serum CRP and Widal O and H agglutinin titres. In receiver-operator characteristic (ROC) analysis of serum CRP for Groups 1 and 2 combined, compared with Group 3, the area under the curve (AUC) was 0.65. These data show that the serum CRP is highest in culture-positive children with enteric fever and reflects the immune response to the infection in this group. Nevertheless, serum CRP had relatively low sensitivity and specificity for confirmed or clinically diagnosed typhoid fever (68 and 58 per cent, respectively at 'cut-off' concentration 30.0 mg/l), and an AUC value only moderately above that associated with no predictive power (0.5). Although of limited use as a primary diagnostic test, a raised serum CRP may still have a place as one of a range of features that facilitate assessment of a febrile child in a typhoid-endemic area.

Objective: To describe the age-specific distribution of typhoid fever including the degree of Salmonella typhi bacteremia among patients evaluated at a large private diagnostic center in Bangladesh, a highly endemic area., Methods: We conducted a prospective-, passive- and laboratory-based study to identify patients with S. typhi bacteremia. Subjects (n = 4,650) from whom blood cultures were obtained during 16-month period were enrolled from private clinics and hospitals throughout Dhaka. Isolation and quantification of S. typhi from blood cultures were performed by the lysis direct plating/ centrifugation method., Results: Bacterial pathogens were recovered from blood of 538 of 4,650 patients (11.6%) evaluated. S. typhi was the single most common pathogen recovered, comprising nearly three-fourths of isolates (72.7%; 391 of 538). Isolation rate of S. typhi was highest in monsoon and summer seasons and lowest in winter months. The majority (54.5%; 213 of 391) of S. typhi isolates were from children who were younger than 5 years, and 27% (105 of 391) were from children in the first 2 years of life. The isolation rate was highest (17.4%, 68 of 486) in the second year of life. The number of bacteria in blood on the basis of colony-forming units per ml of blood by age group was inversely related to age., Conclusions: Detection of S. typhi bacteremia in young children in Dhaka, Bangladesh, was considerably higher than previously appreciated, with a peak detection rate in children < or =2 years of age, indicating the need to reassess the age-specific burden of typhoid fever in the community on a regional basis. Contrary to current recommendations this study suggests that development of new vaccines should target infants and young children.

One hundred children (consecutive) with positive blood culture for Salmonella typhi were studied for clinical profile and complications. The common clinical features were fever (100%), vomiting (58%), abdominal pain (48%), cough (22%) and loose stools (14%) and the Widal test was positive in 75% patients. Eighty per cent of the salmonella isolates were resistant to amoxycillin, chloramphenicol and co-trimoxazole drugs, but all were sensitive to ciprofloxacin and ceftriaxone. Forty patients developed complications: encephalopathy (18), melaena (12), haematemesis (10), epistaxis (4), hepatitis (4), acalculous cholecystitis (4), bowel perforation (3) and nephritis (2). Complications were more frequent in children with multidrug-resistant typhoid. The final antibiotic required to render the children afebrile included ciprofloxacin (80), ceftriaxone, amoxycillin (4), chloramphenicol (4), amoxycillin and gentamicin (4), amoxycillin with chloramphenicol (2), and furazolidone (2). The defervesence time was least with ceftriaxone and greatest with amoxycillin. All the affected children made a complete recovery.

A total of 635 clinically diagnosed typhoid fever patients were bled from three different health institutions in the metropolis of Lagos, Nigeria over a period of 15 months, May 1997 to July 1998. Out of the total blood cultured, 101 (15.9%) isolates of Salmonella species were isolated of which 68 (67.3%) were S. typhi, 17 (16.8%) and 16 (15.8%) were S. paratyphi A. and S. arizonae respectively. The overall isolation rate of S. typhi among patients is 10.7%, with most isolates 45.9% found among the severely-ill young adults, age group 16-30 years. All isolates were subjected to anti-microbial susceptibility testing using 12 different antibiotics: chloramphenicol, ampicillin, cotrimoxazole, gentamicin, colistin sulfate, nalidixic acid, nitrofurantoin, cefotaxime, tetracycline, streptomycin, ofloxacin and ciprofloxacin. All the S. typhi and S. paratyphi A isolates showed resistance to two or more of the 10 of 12 antibiotics tested particularly the 3-first-line antibiotics commonly used (chloramphenicol, ampicillin and cotrimoxazole) in the treatment of typhoid fever in Nigeria. No isolate showed resistance to ofloxacin and ciprofloxacin, however, nalidixic acid and gentamicin showed a moderate and appreciable inhibition to most of our isolates.

The exact reason for hemolysis of glucose-6-phosphate dehydrogenase-deficient (G6PD) erythrocytes in patients with typhoid fever is unknown. Therefore, glucose utilization by normal and G6PD-deficient erythrocytes was measured during incubation with plasma of healthy controls as well as from patients in acute or recovery stages of typhoid fever. Glucose utilization in normal and G6PD-deficient erythrocytes significantly decreased compared to the controls when incubated with plasma of patients with acute typhoid fever, which normalized to the baseline after recovery from typhoid fever, suggesting an acquired alteration in G6PD enzyme properties by Salmonella typhi or its endotoxins.

Clinical application of a dot blot test to detect immunoglobulin G (IgG) (88% sensitivity and specificity) and IgM (12.1% sensitivity and 97% specificity) against flagellar antigen from Salmonella enterica serovar Typhi was performed in Peruvian and Colombian patients with typhoid fever. This test can be used as a good predictor of serovar Typhi infection in regions lacking laboratory facilities and in field studies.

Three hundred and seven healthy food handlers and 34 blood-culture positive enteric fever patients were screened for Salmonellae agglutinins using the Widal test. Of the 307 healthy food handlers, only 3 (1.0%) had an anti-O titre of > or = 1/160 and 8 (2.6%) an anti-H titre of > or = 1/320 for Salmonella typhi, but the majority, 214 (69.7%) and 149 (48.5%) had titres of < 1/20 for O and H agglutinins respectively. Similar agglutinin titres were also seen for S. Paratyphi A, B, and C. In the 34 enteric fever patients, for S typhi, based on anti-O titre of > or = 1/160, 25 persons showed a significant titre, a sensitivity of 73.5%, and a specificity of 99.0%. And 21 persons showed a significant titre of > or = 1/320 for anti-H, a sensitivity of 61.8% and a specificity of 97.4%. Based on these findings, titres of > or = 1/160 and > or = 1/320 for anti-0 and anti-H respectively, were considered diagnostic for enteric fever in Kumasi, Ghana.

Objective: To determine the antibody titre levels to typhoid/paratyphoid fever organisms among apparently healthy volunteers., Design: Cross sectional study., Setting: General community and University Teaching Hospital., Participants: Volunteer sample of 323 apparently healthy individuals with body temperatures < or = 37.8 degrees C., Main Outcome Measures: Questionnaire administration to classify volunteers into three socio-economic status (SES)., Results: There were 35.29% of the apparently healthy population in Jos community with antibodies to typhoid/paratyphoid fever organisms. The presence of these antibodies were neither sex nor SES related. Normal antibody titres were up to 1:40 and 1:80 for O and H Salmonella antigens respectively. Contrary to the general belief, typhoid/paratyphoid fevers have not affected virtually everybody in Nigeria. The difference between those without previous history and those with previous history was significant (p < 0.05) with those in the former category having a higher percentage., Conclusion: For a single sero-diagnosis to have any diagnostic value in Jos community and its environs, only a four-fold rise to what has been found to be normal should be significant. This means that only titres of 1:160 and 1:320 and above for O and H antigens should be considered significant.

Clinical features, laboratory findings, and complications of typhoid fever were correlated with sex through a retrospective case note review of 102 hospitalized culture-positive patients in Durban, South Africa. Intestinal perforation (P = 0.04), occult blood losses in stools (P = 0.04), and a mild reticulocytosis in the absence of hemolysis (P = 0.02) occurred more frequently in males than in females. A single pretreatment Widal O antibody titer > or = 1:640 was also a statistically significant occurrence in males (P = 0. 006). Female patients were significantly more severely ill (P = 0.0004) on admission and had chest signs consistent with bronchopneumonia (P = 0.04), transverse myelitis (P = 0.04), abnormal liver function test results (P = 0.0003), and abnormal findings in urinalyses (P = 0.02). Typhoid hepatitis (P = 0.04) and glomerulonephritis (P = 0.02) were present significantly more frequently in females. Whether these differences were due to differences in host's immune response to acute infection need to be determined in a prospective study.

A monoclonal antibody (MAb) directed against Salmonella typhi 52 kDa flagellin protein has been previously produced by our group. In this study, we have demonstrated that the epitope specific to the MAb is unique to phase 1-d. To map the epitope, plasmids encoding different regions of S. typhi flagellin gene were constructed. Analysis of protein produced from each recombinant plasmid indicated that the epitope specific to the MAb resided within amino acids 171-303 (region IV) of S. typhi flagellin protein. The recombinant region IV flagellin was used to develop an ELISA for the detection of IgM antibody to S. typhi in serum. In the hemoculture-positive typhoid group, the developed ELISA was positive in 77 of 92 cases. In patients with non-typhoidal Salmonella, gram-positive and gram-negative bacteria or dengue virus, the ELISA was negative in all 78 cases. Two from 116 healthy control subjects had positive reactions with the assay. The calculated sensitivity, specificity, positive and negative predictive values of the test were 83.7%, 99.0%, 97.5% and 92.8%, respectively. With such high validity together with the requirement of only a single serum specimen and one day for performing the test, the developed ELISA should become a valuable diagnostic test for typhoid fever.

Despite concerns about adverse effects, chloramphenicol (CMC) continues to be used in certain situations and, due to its low therapeutic index and variable pharmacokinetics, therapeutic drug monitoring (TDM) is often recommended. At our centre, CMC finds applications in typhoid and meningitis and TDM is routinely performed. Elsewhere in Malaysia, however, CMC is used without TDM. We therefore decided to evaluate our TDM for CMC in relation to its roles in CMC therapy in children, who constitute most of our patients. Our objective was also to develop strategies to improve our TDM for CMC use. Data were collected from 168 children given CMC for various indications and monitored by the TDM service. Plasma CMC was determined by HPLC and used to adjust doses to maintain concentrations within a range of 10-25 micrograms/ml. Outcomes measured included daily temperatures and haematological indices. Daily doses and plasma CMC varied greatly. Doses averaged 40.5 mg/kg for neonates and 75.5 for older children. Average peak concentrations were therapeutic in 60% and trough in 42%. Average duration of fever was 6.3 days and it was unaffected by plasma CMC. Typhoid was eradicated in 97% but nine children with other diagnoses died. Side-effects were confined to mild reversible haematological abnormalities which developed in 11% of children at plasma concentrations which tended to be high. We conclude that CMC remains useful in children with typhoid. Its use for other indications, however, should be reviewed. Routine TDM for CMC is probably not warranted, at least until a clearer role is defined by well designed prospective studies.

A series of 122, 9-mer overlapping peptides based on the sequence of the Salmonella typhi GroEL gene was synthesized on the surfaces of polyethylene pins and screened with monoclonal antibody to GroEL and with human sera from patients with typhoid fever and normal healthy blood donors. Three immunogenic epitopes corresponding to peptides EGQDRGYSY, YSYNKETGE and GKGTEEKEK were identified upon screening with the human sera. In addition, screening of the peptides with a monoclonal antibody to GroEL detected binding to a third peptide, KGGKGTEEK, which contains a common overlapping sequence to peptide GKGTEEKEK. Identification and definition of these epitopes will be important in delineating the biological and immunological functions of this protein and in designing better diagnostic tests and vaccines.

In an attempt to evaluate various clinical and laboratory features available within 24 h of admission, prior to the Widal test and bacteriological culture results as potential diagnostic aids in typhoid fever, we undertook a retrospective unit-based case control study in 90 febrile adult and paediatric patients admitted to King Edward VIII Hospital, Durban, South Africa with an initial diagnosis of typhoid fever. A total of 30 blood culture-proven typhoid fever patients (cases) were matched to 60 patients confirmed as not having typhoid fever (controls) by age, sex, race and severity of illness on admission. Features significantly associated with a final diagnosis of typhoid fever were: a pre-admission duration of fever > or = 7 days (odds ratio (OR) 6.9); hepatomegaly (OR 3.2); a normal leucocyte count (OR 10.8); a leucocyte count of < 10.0 x 10(3)/mm3 (OR 30.2); and leucopenia due to absolute neutropenia with a relative lymphocytosis (OR 11.8). Although the sensitivity, specificity and predictive values of any of these features cannot be used reliably to distinguish typhoid fever from other non-typhoidal febrile illness, it is concluded that leucopenia due to absolute neutropenia with relative lymphocytosis, when present, is highly suggestive of typhoid fever. A leucocyte count of > 10.0 x 10(3)/mm3 (OR 0.03) provides strong presumptive evidence against such a diagnosis.

Elevated plasma or serum levels of thrombomodulin (TM) have been reported in some diseases. However, to our knowledge, plasma and serum levels of TM have not been investigated in febrile patients with typhoid fever. Serum TM and creatinine levels were determined in 7 male Japanese febrile patients with typhoid fever and 6 male Japanese healthy controls. The serum TM values of the patients and controls, in arbitrary units/mL, were 5.04 (SD = 1.69) and 2.93 (SD = 0.74), respectively (P < 0.025). The serum creatinine levels of the patients and controls were 0.93 (SD = 0.16) mg/dL and 0.77 (SD = 0.10) mg/dL, respectively, and the lack of any significant difference between them suggests that delayed clearance from the kidneys was not the predominant explanation for the elevated serum TM levels. Although the numbers of patients and controls were small and more studies are needed, we conclude that elevated serum TM levels during the course of a febrile infection with Salmonella serovar typhi may reflect the disease activity.

We conducted a study to evaluate risk factors for developing typhoid fever in a setting where the disease is endemic in Karachi, Pakistan. We enrolled 100 cases with blood culture-confirmed Salmonella typhi between July and October 1994 and 200 age-matched neighbourhood controls. Cases had a median age of 5.8 years. In a conditional logistic regression model, eating ice cream (Odds ratio [OR] = 2.3; 95% confidence interval [CI] 1.2-4.2, attributable risk [AR] = 36%), eating food from a roadside cabin during the summer months (OR = 4.6, 95% CI 1.6-13.0; AR = 18%), taking antimicrobials in the 2 weeks preceding the onset of symptoms (OR = 5.7, 95% CI 2.3-13.9, AR = 21%), and drinking water at the work-site (OR = 44.0, 95% CI 2.8-680, AR = 8%) were all independently associated with typhoid fever. There was no difference in the microbiological water quality of home drinking water between cases and controls. Typhoid fever in Karachi resulted from high-dose exposures from multiple sources with individual susceptibility increased by young age and prior antimicrobial use. Improving commercial food hygiene and decreasing unnecessary antimicrobial use would be expected to decrease the burden of typhoid fever.

Thirty-six adult patients with typhoid fever were studied. Severe, moderate, and mild typhoid fevers were observed in 17 (47.2%), 17 (47.2%), and two (5.6%) patients, respectively. Twenty-eight (77.8%) had either isolated anemia (i.e., anemia unaccompanied by other blood component cytopenias) or mixed cytopenias. Three patients (8.3%) had pancytopenia. Sixteen patients (44.5%) had either total or partial bone marrow suppression. In five (31.3%) with partial suppression, the effect of bone marrow suppression was not reflected in peripheral blood. Sixteen (48.5%) of 33 had peripheral blood cytopenias that were not accompanied by concurrent bone marrow suppression, suggesting a peripheral mechanism responsible for the blood dyscrasia in those cases. No patient had evidence of disseminated intravascular coagulopathy. There was no correlation between clinical severity of disease and bone marrow changes. Bone marrow/peripheral blood changes did not influence the outcome of the disease, since all the patients recovered fully after treatment.

The levels of succinate dehydrogenase (SDG), lactate dehydrogenase (LDG), glucose-6-phosphate-dehydrogenase (G-6-PDG), myeloperoxydase (MPO), glycogen and cationic proteins were determined in the neutrophilic granulocytes of peripheral blood of 79 rabbits after experimental contamination by endotoxin of S. typhi. The bactericidal system of neutrophils was stimulated due to the depression of SDG, activation of LDG and G-6-PDG levels. Administration of indometacinum and chlotasolum blockaded the cyclooxygenase fermentative system of prostaglandin synthesis and thus decreased the activity of S. typhi endotoxin.

We performed genome size estimation of 17 recent human isolates of Salmonella typhi from geographically diverse regions using pulsed-field gel electrophoresis (PFGE) after digestion of chromosomal DNA with restriction endonucleases XbaI (5'-TCTAGA-3'), AvrII (5'-CCTAGG-3') and SpeI (5'-ACTAGT-3'), and summation of the sizes of restriction fragments obtained. All 17 isolates had circular chromosomes, and genome sizes differed by as much as 959 kb, ranging from 3,964 to 4,923 kb (mean genome size = 4,528 kb). The data obtained confirm the usefulness of PFGE in studies of bacterial genome size and are in agreement with recent results indicating considerable genetic diversity and genomic plasticity of S. typhi. The variation in genome sizes noted may be relevant to the observed biological properties of this important human pathogen, including its virulence.

Typhoid is an endemic disease in many countries in the tropics. Different modes of presentation have been reported. This case is one in which the patient presented with convulsions. It is necessary to have a high index of suspicion to make a diagnosis, especially in view of its occasional unusual mode of manifestation.

A study of the drug susceptibility pattern of four blood isolates of Salmonella typhi in Port Harcourt, Nigeria, using the disc method, revealed that all strains were generally sensitive to all the Gram-negative drugs tested, except for nitrofurantoin, neomycin and streptomycin. Three strains were moderately sensitive to both streptomycin (10 mcg) and neomycin (30 mcg) and resistant to nitrofurantoin (300 mcg) while one strain was moderately sensitive to streptomycin and resistant to both neomycin and nitrofurantoin. The isolates were highly sensitive to trimethoprim/sulfamethoxazole (25 mcg), ampicillin (10 mcg), ciprofloxacin (30 mcg), ceftazidime (30 mcg) and chloramphenicol (30 mcg). It is suggested that these strains of S. typhi could be used to develop antigens for more accurate results of the Widal test in Nigeria.

Whole blood cultures are used to study cytokine stimulation and release ex vivo. In the present study this method was compared with a more direct approach and a quantitative reverse transcriptase polymerase chain reaction (RT-PCR) was used to assess mRNA expression for IL-1 beta and tumour necrosis factor alpha (TNF-alpha) and mRNA in whole blood. Stimulation of whole blood from normal donors with lipopolysaccharide (LPS) at various time intervals showed a parallel rise of immunogenic IL-1 beta and TNF-alpha as well as a rise of mRNA expression for IL-1 beta and TNF-alpha with peak levels for IL-1 beta after 4-6 h stimulation and for mRNA TNF-alpha expression after 2 h stimulation. These methods were used to explore cytokine production during the course of typhoid fever and after a 5 km run. In both conditions circulating cytokine concentrations were not influenced, but the TNF-alpha and IL-1 beta mRNA gene expression in circulating whole blood cells was increased in patients with typhoid fever. The LPS-stimulated production of TNF-alpha and IL-1 beta was decreased in both but there was no change for the mRNA content in whole blood for these cytokines. These findings demonstrate that RT-PCR is an attractive method to study the gene expression of cytokines in whole blood, an increased TNF-alpha and IL-1 beta gene expression is present in typhoid fever, and that the LPS stimulated downregulation of cytokines in exercise and typhoid fever may be mediated by post-transcriptional processes.