Diagnosis Of Typhoid Fever Research Articles

The sensitivity of real-time PCR amplification targeting invasive Salmonellaserovars in biological specimens

BackgroundPCR amplification for the detection of pathogens in biological material is generally considered a rapid and informative diagnostic technique. Invasive Salmonella serovars, which cause enteric fever, can be commonly cultured from the blood of infected patients. Yet, the isolation of invasive Salmonella serovars from blood is protracted and potentially insensitive.MethodsWe developed and optimised a novel multiplex three colour real-time PCR assay to detect specific target sequences in the genomes of Salmonella serovars Typhi and Paratyphi A. We performed the assay on DNA extracted from blood and bone marrow samples from culture positive and negative enteric fever patients.ResultsThe assay was validated and demonstrated a high level of specificity and reproducibility under experimental conditions. All bone marrow samples tested positive for Salmonella, however, the sensitivity on blood samples was limited. The assay demonstrated an overall specificity of 100% (75/75) and sensitivity of 53.9% (69/128) on all biological samples. We then tested the PCR detection limit by performing bacterial counts after inoculation into blood culture bottles.ConclusionsOur findings corroborate previous clinical findings, whereby the bacterial load of S. Typhi in peripheral blood is low, often below detection by culture and, consequently, below detection by PCR. Whilst the assay may be utilised for environmental sampling or on differing biological samples, our data suggest that PCR performed directly on blood samples may be an unsuitable methodology and a potentially unachievable target for the routine diagnosis of enteric fever.

Prevalence of Salmonella typhi among Patients with Febrile Illness in Rural and Peri-Urban Populations of Vellore District, as Determined by Nested PCR Targeting the Flagellin Gene

Fever is one of the most common illnesses in all age groups in India. Typhoid fever is a continuing problem in developing countries such as India, which has poor sanitation facilities. The diagnosis of typhoid fever is still made by conventional culture-based isolation and identification. Serologic diagnostic tests, though widely used, have many deficiencies. Our objective was to investigate a molecular nested polymerase chain reaction (nPCR) technique to detect Salmonella typhi among patients with febrile illness in rural and peri-urban communities in Vellore district (Tamil Nadu, India). nPCR targeting the flagellin gene (fliC) was carried out using HotStar Taq DNA polymerase on DNA extracted from the buffy coat fraction of blood samples. Blood culture was done in a completely automated blood culture system, BacT/Alert(R), on prospectively collected blood samples. Relevant clinicopathologic data were obtained. nPCR was found to have a lower limit of detection of 0.01 colony-forming units per milliliter. The prevalence of typhoid fever as estimated by nPCR was 4.7% in pyrexia of unknown origin (PUO) in the rural/peri-urban communities of Vellore district. The prevalence of S. typhi as estimated by blood culture was 2.0%, which was lower than the nPCR estimation. nPCR had sensitivity and specificity of 100% and 97.3%, respectively. The observed agreement between blood culture and nPCR was 0.973 and the Kappa coefficient was 0.59 (p < 0.0001). The frequency of typhoid fever as detected by nPCR was 4.35% among rural patients and 5.32% among peri-urban individuals. nPCR on DNA extracts of buffy-coat samples using HotStar Taq was found to be a valuable and specific technique for diagnosis of typhoid fever.

Diagnosis of enteric fever in the emergency department: a retrospective study from Pakistan

BackgroundEnteric fever is one of the top differential diagnoses of fever in many parts of the world. Generally, the diagnosis is suspected and treatment is initiated based on clinical and basic laboratory parameters.AimsThe present study identifies the clinical and laboratory parameters predicting enteric fever in patients visiting the emergency department of a tertiary care hospital in Pakistan.MethodsThis is a retrospective chart review of all adult patients with clinically suspected enteric fever admitted to the hospital through the emergency department during a 5-year period (2000–2005).ResultsA total of 421 emergency department patients were admitted to the hospital with suspected enteric fever. There were 53 cases of blood culture-positive enteric fever and 296 disease-negative cases on culture. The mean age in the blood culture-positive group was 27 years (SD: 10) and in the group with negative blood culture for enteric fever, 35 years (SD: 15) with a male to female ratio of 1:0.6 in both groups. Less than half (48%) of all patients admitted with suspected enteric fever had the discharge diagnosis of enteric fever, of which only 13% of the patients had blood culture/serologically confirmed enteric fever. None of the common clinical and laboratory parameters differed between enteric fever-positive patients and those without it.ConclusionCommonly cited clinical and laboratory parameters were not able to predict enteric fever.

Jaundice in typhoid patients: Differentiation from other common causes of fever and jaundice in the tropics

While typhoid fever is common in our environment, presentation with jaundice is unusual. The aim of this study has been to determine the clinical and laboratory features that allow early diagnosis of typhoid fever in patients that present with jaundice and differentiate it from other common causes of fever and jaundice in the tropics. This prospective study was conducted between May 1997 and October 1998 at Center Hopitalier Regional de Hombo Anjuoan, Comoros Islands. Patients with clinical and laboratory evidence of typhoid fever were included. Viral or toxic hepatitis, chronic liver disease, sickle cell disease and other causes of jaundice were excluded by clinical examination and appropriate investigations. Serial evaluation of liver function test and abdominal ultrasound were done. Patients were resuscitated with fluids and electrolytes and treated with appropriate antibiotics. Liver involvement was determined using clinical and laboratory parameters. Of the 254 patients with confirmed diagnosis of typhoid fever, 31 (12.2%) presented with jaundice. Their mean age was 24.6+/-9.2SD years. Fever preceded the appearance of jaundice by 8-27 days. In 27 (87.1%) patients, there was hepatosplenomegaly. Serum bilirubin ranged 38-165 micromol/l with mean of 117+/-14SD. Conjugated bilirubin ranged 31-150 micromol/l with mean of 95+/-8SD. Serum aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase were raised with mean values of 180, 105 and 136 IU, respectively. Six (19.4%) patients died compared to 12.1% of non-icteric patients. Typhoid patients may present with varying degrees of jaundice and fever that may be confused with viral, malarial or amebic hepatitis, diseases that are common in the tropics. Physical examination and simple biochemical tests would identify the typhoid patients who should be treated with appropriate antibiotics even before the results of blood culture are available.

A fast and highly sensitive blood culture PCR method for clinical detection of Salmonella enterica serovar Typhi

BackgroundSalmonella Typhi causes an estimated 21 million new cases of typhoid fever and 216,000 deaths every year. Blood culture is currently the gold standard for diagnosis of typhoid fever, but it is time-consuming and takes several days for isolation and identification of causative organisms. It is then too late to initiate proper antibiotic therapy. Serological tests have very low sensitivity and specificity, and no practical value in endemic areas. As early diagnosis of the disease and prompt treatment are essential for optimal management, especially in children, a rapid sensitive detection method for typhoid fever is urgently needed. Although PCR is sensitive and rapid, initial research indicated similar sensitivity to blood culture and lower specificity. We developed a fast and highly sensitive blood culture PCR method for detection of Salmonella Typhi, allowing same-day initiation of treatment after accurate diagnosis of typhoid.MethodsAn ox bile tryptone soy broth was optimized for blood culture, which allows the complete lysis of blood cells to release intracellular bacteria without inhibiting the growth of Salmonella Typhi. Using the optimised broth Salmonella Typhi bacteria in artificial blood samples were enriched in blood culture and then detected by a PCR targeting the fliC-d gene of Salmonella Typhi.ResultsTests demonstrated that 2.4% ox bile in blood culture not only lyzes blood cells completely within 1.5 hours so that the intracellular bacteria could be released, but also has no inhibiting effect on the growth of Salmonella Typhi.Three hour enrichment of Salmonella Typhi in tryptone soya broth containing 2.4% ox bile could increase the bacterial number from 0.75 CFU per millilitre of blood which is similar to clinical typhoid samples to the level which regular PCR can detect. The whole blood culture PCR assay takes less than 8 hours to complete rather than several days for conventional blood culture.ConclusionsThis novel blood culture PCR method is superior in speed and sensitivity to both conventional blood culture and PCR assays. Its use in clinical diagnosis may allow early detection of the causative organism and facilitate initiation of prompt treatment among patients with typhoid fever.

Co-infection of malaria and typhoid fever in a tropical community

A study was carried out on patients clinically diagnosed of malaria or typhoid or both, at Nnewi Anambra State, Nigeria, to investigate the level of association between malaria and typhoid fever infections. The stool culture was used as an additional diagnostic test for typhod fever. The study indicated that out of 256 patients, 29(14.36 %) were diagnosed with concurrent malaria and typhoid fever based on bacterioogcal method as compared to147 (57.42 %) base on serological method. Plasmodum falciparum was the only Plasmodium species isolated. Furthermore, 42.59 % were lkely to have been falsely diagnosed of having concurrent malaria and typhoid fever using serology. Our study indicated that out of 202 (78.90 %) maaria positive patients, 13(6.44 %); 12(594 %) and 3(1.49 %) had concurrent malaria co-existing with Salmonella typhi, S. paratyhpi and S. typhimurium respectively. Malaria was positively associated with typhoid fever (P < 0.05) being more pronounced using serological diagnosis. The difference in the Pasmodium falciprum parasteamia and Salmonella antibody titre was only significant using Widal test. Diagnosis of typhoid fever in malaria positive patients using Widal test solely may lead to misleading and unreliable results.Keywords: Co-infection, Plasmodium, Salmonella, Malaria, Typhoid fever

Diagnostic utility of a single Widal test in the diagnosis of typhoid fever at Aga Khan University Hospital (AKUH), Nairobi, Kenya

Typhoid fever is a systemic illness caused by Salmonella enterica serovar typhi (S. typhi) and is endemic in Kenya, where a single Widal test done on an acute phase serum is the most commonly used test. Using a cut-off value of 1:320 for both O and H agglutinins as being diagnostic of S. typhi, only 18 (26%) of our patients had diagnostic titres; 37 (53.6%) had O and H titres less than 1:40. Our study showed that Widal testing done on an acute phase serum of a patient suspected to have typhoid fever had limited diagnostic capability given its low sensitivity.

Evaluation of Typhidot (IgM) for Early Diagnosis of Typhoid Fever

Typhoid fever still continues to be a major public health problem, particularly in many developing countries. A simple, reliable, affordable and rapid diagnostic test has been a long-felt need of the clinicians. We, therefore, prospectively evaluated the sensitivity and specificity of Typhidot (IgM), a serological test to identify IgM antibodies against Salmonella typhi. The study was carried out in the department of Microbiology, Mymensingh Medical College, Mymensingh between June, 2006 and July, 2007, on a total of 100 samples from clinically suspected patients to have typhoid fever. Blood culture as well as Typhidot test were performed for each of the cases. Out of 100 clinically diagnosed typhoid fever, 14 were blood culture positive for S. typhi and 73 were Typhidot (IgM) positive. Among 14 culture positive cases, 13 (92.85%) were Typhidot (IgM) positive. The test was also positive in 04 (20%) out of 20 febrile controls. None of the healthy controls was positive by Typhidot (IgM). The sensitivity, specificity, positive predictive value and negative predictive value of the test using blood culture as gold standard were 92.85%, 90.00%, 76.47% and 97.29% respectively for typhoid fever. Typhidot (IgM) test is rapid, easy to perform and reliable test for diagnosing typhoid fever, and useful for small, less equipped laboratories as well as for the laboratories with better facilities. Key words: Typhoid fever, Salmonella typhi, Typhidot (IgM) test doi: 10.3329/bjmm.v3i1.2964 Bangladesh J Med Microbiol 2009; 03 (01): 10-13

Cholestasis preceding ileal perforation in a patient with typhoid fever

Typhoid fever is a severe febrile systemic infection caused by gram-negative bacillus, Salmonella typhi [1]. Hepatitis may occur during the course of typhoid fever. To our knowledge, typhoid fever associated pure cholestasis has been reported only once before [2]. A 43-year-old man was admitted to our hospital with the chief complaint of abdominal pain. He had been well until 2 weeks earlier, when abdominal discomfort, fever, and jaundice developed. His past medical history was unremarkable. The temperature was 39 C. He had been admitted to a physician with those complaints. Oral ciprofloxacin (500 mg bid) was prescribed, and he used it for 5 days. Despite antibiotic therapy, the symptoms did not improve. The degree of abdominal pain increased progressively, and was accompanied by constipation. The patient was admitted to the emergency department (ED) of our hospital. On admission, he appeared ill and malnourished. The abdomen was distended and diffusely tender. The laboratory findings are shown in Table 1. There were fluid-air levels on the plain abdominal X-ray study. Abdominal ultrasonography revealed free fluid between small intestine segments. The patient underwent exploratory laparotomy for an acute abdomen. At laparotomy, nearly 300 cc hemorrhagic fluid and enteric contents were found within the peritoneal cavity. Beginning from 100 cm proximal to the ileoceacal valve, there were multiple perforated areas in the ileum. The perforated segment of ileum was resected. Postoperative care included 400 mg intravenous ciprofloxacin and 1,500 mg metronidazole per day. Pathologic examination of the removed intestine revealed ulcers, lymphoid hyperplasia, vascular congestion, inflammation and reactive lymphoid hyperplasia in the ileum and cecum (Fig. 1). These findings are compatible with a Salmonella typhi infection. Serologic tests and blood cultures for typhoid fever were negative. After surgery, because of elevated liver enzymes the patient was referred to the gastroenterology department. The liver tests are shown in Table 1. Other biochemical tests were within normal limits. Serologic tests for viral hepatitis, including hepatitis A, B, and C viruses, cytomegalovirus, Epstein– Barr virus, and herpes simplex virus, were negative. Autoantibodies (i.e., antinuclear, antimitochondrial, antismooth muscle, anti-liver–kidney microsomal enzymes, anti-soluble liver antigen) were also negative. Abdominal ultrasonography showed hepatomegaly (175 mm) and splenomegaly (145 mm); the biliary tract was normal. The elevation of the liver enzymes was attributed to Salmonella typhi infection. During follow-up, this liver enzyme elevation decreased gradually (Table 1). There are at least 16 million new cases of typhoid fever around the world, and approximately 10,000 patients are hospitalized annually for this infection in Turkey [3]. The diagnosis of typhoid fever is established on the basis of history, clinical examination, isolation of Salmonella typhi, and a positive Widal test. It is also confirmed intraoperatively by the typical findings of antimesenteric perforations of the ileum, and postoperatively by the pathologic examination that shows histological evidence of typhoid inflammation in the tissue obtained from the edges of S. Koklu (&) Karargahtepe Mahallesi, Kumrulu Sokak, 18/2, Kecioren, Ankara, Turkey e-mail: gskoklu@yahoo.com

CR19P A RARE CASE OF MASSIVE GASTROINTESTINAL HAEMORRHAGE: AN IMPORTANT CONSIDERATION IN TRAVELLERS

We report a case of massive gastrointestinal haemorrhage in a traveller who presented to a tertiary hospital emergency department in Melbourne, Australia. An 18 year‐old man from India presented with two weeks of malaise, anorexia, fever and generalised abdominal pain and had massive rectal bleeding on presentation. He underwent computed tomography angiography before urgent laparotomy and ileocolic resection of a bleeding ulcer in the terminal ileum. Blood cultures subsequently grew Salmonella typhi. Histopathology showed multiple areas of ulceration centred on Peyer's patches, transmural mononuclear cell infiltrates and focal non‐necrotizing granulomas. A diagnosis of enteric fever causing massive bleeding from an ulcer in the terminal ileum was made and the Health Department notified. The patient had four weeks of antibiotic therapy and made a full recovery.Surgery was once thought contraindicated in enteric fever complicated by bleeding, citing a tendency for the bowel to be friable and difficulty locating the site of bleeding in multiple ulcers. Bleeding and perforation occur from necrosis of Peyer's patches. However, evidence shows this is limited to the terminal ileum and proximal colon, allowing directed surgical excision. In the current age of international travel, surgeons must be increasingly aware of relevant diseases that may have had their origins overseas. Enteric fever should be considered in patients with rectal bleeding who are travellers and immigrants from endemic areas with a compatible illness.

Comparative study of dot enzyme immunoassay (Typhidot-M) and Widal test in the diagnosis of typhoid fever

We compared the sensitivity and specificity of Typhidot-M and Widal test with blood culture (gold standard) for diagnosing typhoid fever in 105 children aged 1-15 years admitted with clinical suspicion of typhoid fever. Of the 105 cases, blood culture was positive for S.typhi in 41 (39%) children, Widal test was positive in 48 (45.7%) and Typhidot-M was positive in 78 (74.3%) cases. Sensitivity and specificity of Typhidot-M was 92.6% and 37.5% while sensitivity and specificity of Widal test was 34.1% and 42.8%, respectively. In children with fever of less than 7 days duration, Typhidot-M was positive in 97%, compared to 24.2% by Widal test. Typhidot-M is a simple and sensitive test for early diagnosis of typhoid fever in children.

Distribution of antibody titer against Salmonella enterica among healthy individuals in nepal

BackgroundEnteric fever is an endemic problem in Nepal and Widal agglutination test is widely used for its diagnosis but a normal baseline titer in healthy population and cutoff values have not been established.MethodsWe measured average baseline antibody titers against "O" and "H" antigens of Salmonella enterica serotype Typhi and "H" antigens of serotypes Paratyphi A and Paratyphi B among apparently healthy blood donors in Nepal. The antibody titers were measured using Standard Widal Confirmatory Quantitative Tube test.ResultsAmong the 100 blood samples collected from healthy volunteers, 62 individuals had significant antibody titers (≥ 1:20) against one of the four antigens against S. enterica. Among 54 samples with an anti-O titer against serotype Typhi, 15 and 36 samples had titers of ≥ 1:60 and ≥ 1:40, respectively. A significant proportion (12% of all) had anti-O titer of ≥ 1:80. Similarly, among the 59 samples demonstrating anti-H titers of ≥ 1:20 to S. enterica serotype Typhi, 29 had a titer of ≥ 1:80 and 12 had 1:160. For S. enterica serotypes Paratyphi A and B, anti-H titers of ≥ 1:20 were found only in 12% and 3%, respectively, of all samples tested.ConclusionWhen a single Widal agglutination titer is used for the diagnosis of enteric fever, it will be more appropriate to change the currently used cutoff levels against S. enterica serotype Typhi to > 1:80 for anti-O and > 1:160 for anti-H titers for Nepal.

ミャンマーで感染し帰国後発症した輸入つつが虫病の1 例

Scrub typhus is widespread in rural south and southeastern Asia and the western Pacific. The scrub typhus incidence is the highest among vector-borne diseases in Japan, but imported cases are extremely rare. A 49-year-old man admitted for persistent fever, headache, and rash after returning from Myanmar had been exposed to mosquito and tick bites while doing a 12-day forest inventory in Myanmar. On admission, he had a generalized maculopapular rash but no apparent eschars characteristic of scrub typhus. Blood examination and abdominal ultrasonography showed elevated liver enzymes, thrombocytopenia, and hepatosplenomegaly. Repeated blood smears and blood cultures were negative for malaria infection and bacteremia. Dengue fever was denied by both PCR and serology. The patient deteriorated on the ninth day and suffered complications of rhabdomyolysis, pneumonia, and enteritis. Based on a tentative diagnosis of typhoid fever or rickettiosis, we administratered ceftriaxone and minocycline, which dramatically reduced clinical signs and symptoms. After discharge on day 19, immunofluorescence assay showed significantly increased antibodies for Orienta tsutsugamushi serotype Gilliam, first discovered in Myanmar. All serological results were negative for other rickettioses, leptospirosis and Q fever. Given the many travelers from Japan visiting endemic scrub typhus areas, we must recognize cases of imported scrub typhus among those travelers with fever and rash returning from endemic areas.

Specimens and culture media for the laboratory diagnosis of typhoid fever

Culture of S. Typhi is necessary for the definitive diagnosis of typhoid fever and provides isolates for antibiotic susceptibility testing and epidemiological studies. However, current methods are not fully optimised and sourcing culture media and bottles for culture media may be problematic. In two hospital laboratories in Viet Nam, comparisons of media for blood and stool culture were conducted. The effect of the volume of blood or stool on culture positivity rate was examined and direct plating of the blood buffy coat was trialed. For 148 suspected typhoid fever cases, ox bile broth (58 positive) and brain-heart infusion broth containing saponin (63 positive), performed equally well. For 69 confirmed adult typhoid fever cases, large-volume (15 ml) blood culture gave the same sensitivity as 1 ml of bone marrow culture. For 44 confirmed typhoid fever cases, the direct plating of the buffy coat was positive in 28 cases. For 263 positive stool cultures, selenite F and selenite mannitol performed equally well and culturing 2 g rather than 1g increased the isolation rate by 10.5%. For the diagnosis of typhoid fever by blood culture the medium should be a rich nutrient broth containing a lysing agent. In adults 1 ml bone marrow or 15 ml blood culture gave similar results. Where isolates are needed for susceptibility testing or epidemiological studies, but resources for culture are scarce, direct plating of the blood buffy coat can be used with a 50% fall in sensitivity compared to standard blood culture.

The laboratory diagnosis of enteric fever

The diagnosis of enteric fever currently depends upon the isolation of Salmonella from a patient, most commonly by blood culture. This facility is not available in many areas where the disease is endemic. Serodiagnosis depends upon the 100-year-old Widal test, and other serological diagnostic tools have limitations because of their low sensitivity and/or specificity. The most promising recently published results are from PCR-based amplification of DNA from the blood of enteric fever patients but again this technique is not available where it is most needed. Antigen detection has not been investigated for well over three decades and detecting an immune response specific for typhoid fever has been done only with antibody detection. There is an urgent need for the rational design and evaluation of effective and appropriate diagnostics for enteric fever which must include the emerging threat of S. Paratyphi A.

Typhoid fever research in developing countries

Typhoid fever remains a major public health problem in the developing world with very poor estimates of the number of cases and deaths annually. Continued research on the epidemiology, ecology, pathogenesis, diagnosis, treatment and prevention of typhoid can most optimally be pursued in the endemic regions which, unfortunately, also suffer from a lack of research capacity, funding support, and institutional infrastructure. Much needs to be done to promote and strengthen typhoid fever and other infectious disease research in these regions if true progress is to be made. It is thus reassuring to see that the two special issues of JIDC on enteric fever contain so many regional reviews written by scientists based in, and mainly from, developing countries. There is a great deal of very valuable and unique information in these articles. In Indonesia, Hatta et al. explain the increasing problems on the island of Sulawesi where resistance to Salmonella Typhi has only developed very recently. Yang et al. in China describe the increasing problems associated with Salmonella Paratyphi A, a serovar which—at least for isolates from the Aga Khan University laboratories in Karachi, Pakistan—was resistant to multiple antibiotics (MDR) but is now becoming susceptible once again. This is at the same time and in the same population as increasing MDR in S. Typhi. Information across sub-Saharan Africa is very scarce and the issues clearly require urgent and rapid action, particularly in Malawi, where the burden of nontyphoidal Salmonella is increasing, and in East Africa (Ethiopia and Kenya) which seems to have a high burden of typhoid fever.. India and Nepal remain major focal points for typhoid and paratyphoid fever and even in southern Europe (Italy) transmission is occurring. What is reported in these articles builds on the knowledge base which has been captured in the series of international conferences on typhoid fever and other salmonellosis, beginning in 1991 and to be continued in Kenya in 2009. Over the nearly 20 years of their existence, these conferences have illustrated the important contributions made by researchers in the developing countries towards a better understanding of enteric fever in all its dimensions. The World Health Organization has been a key partner in all these conferences and sees the diagnosis, prevention, and control of typhoid fever as an urgent public health priority. In the context of rapidly changing knowledge on all aspects of typhoid fever, the JIDC plays a very important role in disseminating such knowledge and bringing together the scientific communities from both the developed and developing world to share knowledge and experiences, and jointly address this important threat to human health security.

Evaluation of false negativity of the Widal test among culture proven typhoid fever cases

The Widal test is the most common, specific and quick diagnostic method available in the world for diagnosis of typhoid fever; however, false negativity is one of the obstructive features of the test. The aim of this study was to evaluate the associated factors with Widal test negativity in an endemic area. Widal test negativity was retrospectively analyzed among culture-proven typhoid fever cases. The potential features including age, gender, previous antibiotic usage, duration of symptoms, leucopoenia, hematocrit value, and erythrocyte sedimentation rate (ESR) were evaluated for association with Widal test negativity. A total of 166 culture-proven typhoid fever cases (93 or 56.0% males) were included in the study. The mean age +/- SD was 23.3 +/- 10.6 years. Mean time of interval between first symptom and test performance time was 10.6 +/- 7.8 days. The Widal test (STO and/or STH) was found positive in 75 cases (45.2%). The statistical analyses revealed that none of these variables were significant for false negativity of the Widal test. Age was found to be a possible factor for a false negative Widal test (p=0.06). Of existing compatible clinical findings, age should be considered in cases of Widal test negativity.

Clinical Presentation and Blood Culture Scenario of Typhoid Fever among Urban Children of Bangladesh

Background: Typhoid is a serious disease caused by S. enterica serotype typhi. It is endemic in Bangladesh with occasional epidemic. In children it may present as a nonspecific fever making diagnosis very difficult causing delay in treatment. Moreover, with emergence of multi-drug resistant strains of S. typhi (MDR- St) management has become more difficult. Blood culture is the most reliable and feasible method for choosing the right drug to treat. Objectives: To evaluate the clinical picture at presentation; to facilitate early diagnosis of Typhoid in urban children and to help to apply an early effective therapy against it. Methods: A prospective study was performed on 50 admitted children with typhoid fever in Bangladesh Medical College Hospital. The clinical presentation, source of water supply, sanitation, food habits, sensitivity of blood culture, duration of response to antibiotics etc. were recorded in a structured questionnaire. Results: Male and female ratio was 1.8:1 with a mean age of 5.17 ± 2.63 years. Majority came from medium economic group (46.0%). Fever was the main presenting feature in all cases with mean duration of 9.18 ± 5.15 days at admission. Fever was sudden in onset in 78.0% and irregular in 82.0% cases. Cough, diarrhea and vomiting were common symptoms while constipation was found in 12.0% of cases only. Relative bradycardia was not a common feature. Blood culture was positive in all cases and mostly within 7 days of duration (60.0%). 98.0% of isolated organism was sensitive to Ceftriaxone. There was significant relationship between incidence of MDR-St and non MDR-St with recent travel history (P < 0.05). The mean time to defervescence was 4.80 ± 1.89 days. Mean duration of hospital stay was 9.30 ± 2.10 days. All the cases recovered completely. Conclusion: Clinical presentation of typhoid in children is different from that in adults. MDR-St strains are common in urban area. Random and empirical use of antibiotics is raising the MDR strains against conventional drugs leaving only the best response to expensive antibiotics. We recommend that early diagnosis; proper supportive care and rational use of antibiotics with adequate dose and duration can avoid the morbidity and mortality. Vaccines for infants should be developed and better incorporated in the Expanded Program on Immunization (EPI). There should be a national guideline for effective control of typhoid.

The comparison of cultures, widal agglutination test and polymerase chain reaction as a diagnostic tool in typhoid fever

Abstract Typhoid fever caused by Salmonella typhi, paratyphi A and B, is an important cause of morbidity and mortality in many developing countries. A rapid and sensitive method for the detection of S. typhi is essential for early diagnosis of typhoid fever and effective therapy. In this study 45 febrile patients who were suspected to have enteric fever were enrolled, and the results of blood cultures, widal agglutination tests and Polymerase Chain Reaction in these cases were evaluated. Group I consisted of 11 patients with diseases other than salmonella infections, group II represented 6 patients with positive cultures, and group III represented 28 patients with negative blood cultures negative but who were clinically suspected cases that had a medical history of using variable antimicrobial agents. Two positive PCR results were present; one of them was in culture positive group (16,6%) and the other was in culture negative group (3,5%). In our study widal agglutination tests and cultures were found not to be helpful in differential dignosis. Although PCR based detection of S. typhi is reported to be a sensitive and specific test for the diagnosis of enteric fever, in our study the benefit of this method in the diagnosis of especially patients who were treated with antimicrobial therapy was not clearly determined. Other methods to increase sensitiviy and specificity to levels such as those of real time PCR should be developed and large-scaled studies should be done in endemic and non-epidemic regions.

Typhoid Fever in Southern Taiwan: A Medical Center Experience

Typhoid fever is caused by Salmonella enterica serotype Typhi (5. typhi). Growing communication between Taiwan and neighboring regions in recent years could be an important source of typhoid fever. The aim of this study was to analyze the clinical characteristics of typhoid fever treated at a medical center in southern Taiwan. The study group consisted of 33 patients (aged 1-68 years) who had clinical symptoms and culture-confirmed typhoid fever. They were studied over a 20-year period from January 1987 to December 2006 at a tertiary referral hospital in southern Taiwan. Their medical records were reviewed and clinical data were collected. The study group included 17 males and 16 females. They were divided into two groups: group I (< or = 17 years; n=14) and group II (>17 years; n=19). Only one patient (7.1%) in group I had a history of travel, compared with 47.4% (n=9) in group II (p = 0.045). Patients in group I also had less chills (group I vs. group 11=7.1% vs. 57.9%, p = 0.004). A higher proportion of group I patients had respiratory problems (cough, group I vs. group II = 57.1% vs. 26.3%) and a higher proportion of group II patients developed complications (group I vs. group II = 14.3% vs. 36.8%), but the differences were not significant. Pediatric patients with typhoid fever in southern Taiwan had less history of travel and developed fewer chills than adult patients. Careful examination and familiarity with the clinical manifestations are important factors in the early diagnosis of typhoid fever.