Enteric fever: diagnostic value of clinical features.

OBJECTIVES: to evaluate the diagnostic value of clinical symptoms and signs in enteric fever and to propose a clinical diagnostic criterion. DESIGN: Prospective observational study. SETTING: Kathmandu Medical College, Teaching Hospital, Kathmandu, Nepal. MATERIALS AND METHODS: febrile patients with clinical diagnosis of enteric fever were included in the study with the aim of confirming diagnosis with blood culture, or bone marrow culture and evaluating the diagnostic accuracy of various clinical signs and symptoms. RESULTS: 64% of the clinically diagnosed cases had blood/ bone marrow culture positive. The diagnostic accuracy of the various symptoms and signs excluding fever was between 42%-75.5%. Majority of the symptom and sign did not have very high diagnostic accuracy. Hence a diagnostic criterion was proposed and clinical features with diagnostic accuracy more than 50% were taken into consideration. Major criteria included fever with diagnostic accuracy of 64%, headache with accuracy of 75.5% and relative bradycardia with an accuracy of 66%. Minor criteria included vomiting, diarrhoea, Splenomegaly, chills and abdominal pain /discomfort with diagnostic accuracy of 57%, 55%, 55%, 53% and 51% respectively. Finally after combination of various major and minor criteria a final diagnostic criterion was proposed having an accuracy of 66% and including both major and minor clinical symptom and sign. CONCLUSION: clinical diagnosis of enteric fever will be very helpful in a country like ours. Though none of the clinical symptoms and sign have very high diagnostic accuracy a diagnostic criteria may be helpful. Criteria including both major and minor signs and symptoms would be the most appropriate diagnostic tool as it includes the important abdominal symptoms and signs of enteric fever.

Blood culture isolates from children admitted to Medical Unit III, Yangon Children's Hospital, 1998.

A one year study (August 1998-July 1999) of bacteremia in febrile children was carried out in the Medical Unit (III), Yangon Children's Hospital (YCH), Myanmar, to determine: (1) the bacteria responsible for fever of five days or more in children; (2) the antibiotic sensitivity pattern of these bacteria. Children aged one month to 12 years who had fever for five days or more and who did not receive antibiotics within the first 48 hours irrespective of the diagnosis were included in this study. A total of 120 patients fulfilled the criteria. Bacteria could be isolated from 65 cases (54.2%). The commonest organism isolated was Salmonella typhi (43.1%). Others included Escherichia coli (12.3%), Staphylococcus aureus (7.7%), Pseudomonas aeruginosa (7.7%); Streptococcus, Shigella, Diplococcus, Klebsiella and Acinetobacter were also isolated. The Salmonella typhi were resistant to conventional antibiotics (ampicillin, amoxicillin, chloramphenicol, and co-trimoxazole); however, they were sensitive to amikacin, netilmicin, nalidixic acid, and cephalothin. A cluster of enteric fever cases from Mingalartaungnyunt township was noticed and was reported to the Directorate of Health. Changes in the incidence and etiology of bacteremia in hospitals are well documented. Sentinel surveys of bacteremia in major hospitals should be carried out in order to detect the changing patterns of bacteremia and antibiotic sensitivity; such surveys will be of great help in establishing local antibiotic policies.

Antibody response in typhoid fever in endemic Indonesia and the relevance of serology and culture to diagnosis.

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.

Virulence of Malaysian isolates of Orientia tsutsugamushi in mice.

The pathogenicity of Malaysian isolates of Orientia tsutsugamushi was investigated by a mouse virulence assay. The isolates could be differentiated as low (4 isolates), moderately (3 isolates) and highly virulent (2 isolates) based on the different responses in infected mice. No direct correlation between severity of human scrub typhus infections and virulence of the O. tsutsugamushi in mice was observed. Mice infected with virulent strains of O. tsutsugamushi showed splenomegaly, ascitis accumulation and enlargement of kidneys and livers whereas avirulent O. tsutsugamushi strains were asymptomatic and exhibited ruffled fur for a short period after infection. There was low antibody response in mice infected with isolates of low pathogenicity as compared with those of highly virulent isolates. Upon dissection of the infected mice, enlargement of mouse organs such as spleen, kidney and liver was noted. Presence of rickettsemia in mice was confirmed by the growth of O. tsutsugamushi in the L929 cells when inoculated with blood from infected mice. O. tsutsugamushi was also cultured from the peritoneal exudates of the infected mice. However, DNA of O. tsutsugamushi was only detected in the peritoneal exudates (by PCR) and blood (by cell culture) and not from other tissue samples.

Histoplasmosis: an unusual presentation.

Histoplasma capsulatum (HC) infection is rare in India. We document a case of unilateral adrenal histoplasmosis in a 56 year male. The patient presented with hepatosplenomegaly, unilateral adrenal mass and significant weight loss. Since FNAC of adrenal mass was inconclusive, he underwent splenectomy, adrenalectomy and liver biopsy, histology of these specimens revealed HC only in adrenal mass. Subsequently, histoplasmin test was also performed which was also found to be positive. He responded well to parenteral amphotericin B and is under regular follow-up with no complaints now.

Hepatosplenomegaly caused by an extract of cyanobacterium microcystis aeruginosa bloom collected in the Manguaba laggon, Alagoas - Brazil

Cyanobacteria (Microcystis aeruginosa), which produce powerful hepatotoxic cyclopetpides, were collected and submitted to the determination of toxicity through intraperitoneal injections made in 30 and 90 days-old Swiss albino mice. The liver and the spleen were histopathologically analyzed and the weight and vital signs development were monitored. Test of toxicity resulted in a LD 50 of 154.28 mg.Kg -1 . M.aeruginosa represented 95 (per cent) of the analyzed biomass. The ratios between liver weight and body weight in the animal inoculated with a single dose were 6.0 (per cent) and 7.2 (per cent), with multi doses 7.0 (per cent) and 7.5 (per cent) and in the control animals 4.0 (per cent) and 5.0 (per cent), for adult and young animals, respectively . There was an accentuated increase in the volume and weight of the spleen, and the animals inoculated with a single dose showed a ratio between spleen weight and body weight of 0.67 (per cent) and 0.37 (per cent), with multidoses 1.22 (per cent) and 1.05 (per cent) and the control animals the ratio was 0.12 (per cent) and 0.15 (per cent), for adult and young animals, respectively. The young animals inoculated with single and multi doses had an increase of 150 (per cent) and 407 (per cent) in the spleen size while the adults increased, 607 (per cent) and 845 (per cent), respectively, in relation to the control. The histopathological analysis showed strong differences in the structure of the hepatic parenchyme in control animals and in those exposed to the M.aeruginosa extract. The main alterations were the congestive aspect, including the sinusoid, and intrahepatic haemorrhagia. The histopathological analysis showed considerable increase in the number of multinuclear giant cells in the spleen of the animals intoxicated by M.aeruginosa.