Search

An outbreak of typhoid fever was observed in a group of students and accompanying teachers during a journey to Haiti in summer 1991. All (6) infected persons were symptomatic and rapidly cured by antibiotics. The Salmonella typhi strains isolated from blood cultures were all identical by ribotyping. All the participants had a medical checkup and stool cultures were obtained; asymptomatic carriers could be excluded. Secondarily infected persons were not observed. The infectious source has not been identified, but various hypotheses are considered. Oral vaccination does not appear to modify the risk of infection in exposed persons.

The causative agents of typhoid fever isolated in 1990 in the Soviet Union were mainly sensitive to ampicillin, tetracyclines and streptomycin and slightly sensitive to rifampicin and gentamicin. The number of the strains resistant to rifampicin and gentamicin is ever increasing. The strains of Salmonella typhi isolated in the Soviet Union were sensitive to chloramphenicol unlike the strains isolated in India which were characterized by high resistance to this antibiotic. The phage type pattern of the isolates was mainly represented by the phage types A1 (57.5 per cent) and B1 (30.8 per cent). No relation between separate phage types of S. typhi and their antibiotic resistance phenotypes was detected.

A total of 11391 strains of S. typhi were received at the National Salmonella Phage Typing Centre at New Delhi during January 1990- August 1992, from various regions of India. Of these, 39.7 per cent were from north India, 37.5 per cent from central India and 22.8 per cent from south India. 64.5 per cent of S. typhi were found to be multidrug resistant (MDR), maximum resistance being observed in 1991 (71.6%) while it was least in 1990 (50.05%). There was a slight decline in the percentage of MDR strains in 1992. Region-wise analysis of the resistant strains showed maximum number in central India (71.32%), whereas it was least in the south (55.2%); 62.34 per cent of strains received from north India were MDR. Irrespective of the year or region, the predominant resistance pattern remained AMCSXTTE. The commonest phage type was E1, followed by 0 and A. This pattern was also seen in the MDR S. typhi. Certain degraded Vi strains, untypable Vi strains and Vi negative strains were also multidrug-resistant. An important change observed in this study was that a small number of strains belonging to phage types C1, K1, 28, 40, 41 and 42 which were always sensitive earlier, had developed multidrug resistance. Small outbreaks due to one phage type (e.g., 28 and 51) were short lived and subsided spontaneously. More diversity of phage types was observed in north India as compared to central and south India.

A typhoid fever outbreak affecting 54 school students occurred in a Public School of Móstoles, Madrid. The date of onset was 11 June 1991 and the last detected case was 8 July 1991. Salmonella typhi was cultured from blood and/or stool samples corresponding to 54 patients and one food-handler. There were no secondary cases detected. Epidemiological investigation suggested a salad or a custard as the common source. Patients and the food-handler were treated with ampicillin/amoxicillin for up to three weeks. There were seven relapses that were also treated with the same antibiotics with success. None were found to be excreting the organisms when tested after four months. All the Salmonella typhi isolated strains were phagetype 34, biotype Xylose +, Tetrationate Reductase + and harboured a similar 22 Mdal plasmid, they were also susceptible to the antibiotics tested.

Background: References about isolation of strains of Salmonella typhi multiply resistant to antimicrobials and native from Spain are very scant. We describe here two cases of typhoid fever produced by two identical strains of Salmonella typhi. Both strains are multiresistant and autochthonous, judging from epidemiological investigations., Method: Microbiological diagnosis was made by means of isolation of causative microorganism from blood and stool, in the first case, and only from stool, in the second one. Antimicrobial susceptibility was ascertained using a minimal inhibitory concentration micromethod., Results: Identification of Salmonella enterica ser. typhi and determination of its resistance to many antimicrobials. Native origin of both strains verified by means of epidemiological investigation. Healing achieved in both cases with ciprofloxacin., Conclusions: We stand out the rarity of isolating native multiresistant strains of Salmonella typhi in our country, as well as the great epidemiological interest of our finding. We think that diagnosis of these diseases must be made by culturing suitable specimens and isolating causal microorganisms, what will us to determine antimicrobial susceptibility. Finally, we emphasize the resolution of the illness with ciprofloxacin. We consider that this third generation quinolone is a suitable alternative in these cases.

A total of 1452 cases of typhoid fever was notified in Singapore from 1980-9. The morbidity rates of indigenous cases showed a steady decline from 5.9 per 100,000 population in 1980 to 1.2 per 100,000 population in 1989. The mean case fatality was 0.8%. Children, adolescents and young adults were most susceptible to typhoid fever. There was no significant difference in morbidity rates between the major ethnic groups. The vast majority of indigenous cases were sporadic while outbreaks accounted for almost one third of them. Food was the main vehicle of transmission. The commonest indigenous phage types were B1, D1 and A. Antimicrobial resistance was infrequently seen. The proportion of imported cases rose from 32% in 1980 to 72% in 1989. Almost half (48.5%) of all imported cases were local residents who contracted typhoid fever while travelling in endemic countries. As imported cases assume greater importance in the epidemiology of typhoid fever in Singapore, further drop in typhoid fever incidence would require reduction of travel-related cases through greater awareness of food hygiene and effective vaccination.

Multidrug-resistant Salmonella typhi has spread to many parts of India, causing severe therapeutic problems. Of the 305 clinically suspected cases of enteric fever seen at Kasturba Hospital in Manipal, Karnataka between January 1990 and June 1991, Salmonella bacteremia was detected in 134 patients; 102 of these were caused by S. typhi. Eighty (78.4%) of the isolates from S. typhi-infected patients were resistant to conventional antibiotics used in the treatment of typhoid fever (i.e., ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole). No in vitro resistance was observed to ciprofloxacin, norfloxacin, and gentamicin. Major complications were seen in four patients infected by multiresistant S. typhi; three responded well to ciprofloxacin. The fourth patient died of hemorrhage and acute renal failure, even after receiving ciprofloxacin. In addition, less severe complications such as hepatitis and jaundice were observed in 12 other patients. Seventy-six of the multiresistant S. typhi belonged to phage type O biotype II and four were of untypeable Vi strains. The emergence of multidrug-resistant S. typhi has necessitated the use of fluoroquinolones in the therapy for enteric fever.

Most Salmonella typhi isolated in Spain are susceptible to antibiotics commonly used in its treatment as chloramphenicol, ampicillin and cotrimoxazole. Three multiresistant strains have been isolated from different patients the last two years. Two phage type M1, biotype xylose tetrationate + strains were isolated from blood of two patients in Bembibre (León). One phage type E1a biotype xylose + tetrationate reductase + strain was isolated from blood and faeces of one patient in Barcelona. All strains harboured a 79 Mdal plasmid responsible for multiresistance, chloramphenicol acetyl transferase production and conjugative.

Sixteen multiple drug resistant strains of Salmonella typhi belonging to Vi-phage types E1 (14) and O (2) and isolated in Southeast India in 1991 were characterized. All strains were resistant to chloramphenicol and the majority to trimethoprim and ampicillin. In all strains these resistances were encoded by plasmids of the H1 incompatibility group with molecular weights ranging from 110 to 120 megadaltons. Physicians in European countries should be aware that treatment may fail if patients with typhoid fever who have recently returned from the Indian sub-continent are given first-line treatment with chloramphenicol, trimethoprim or ampicillin. With the possible exception of young children, ciprofloxacin is currently the best choice for treatment of such patients.

A panel of monoclonal antibodies were generated against the surface polysaccharide antigens of the cell envelope of Salmonella typhi. Four clones (IgM) were specific for the capsular Vi polysaccharide, and one clone (IgG3) reacted selectively with the S. typhi lipopolysaccharide in enzyme immunoassay. On the basis of their reactivity pattern and binding affinity, MATy-V7 (IgM) and MATy-O9 (IgG3) antibodies were selected for further characterization of their antigenic specificity. In an inhibition enzyme immunoassay with rabbit factor-specific anti-Salmonella antibodies as the competing agents, the reactivity of MATy-V7 and MATy-O9 were significantly inhibited by the anti-Vi and anti-O9 antisera, respectively. Moreover, both the Vi- and O9-specific monoclonal antibodies were shown to be useful serotyping agents by correct identification in slide agglutination tests of 32 clinical isolates of all the S. typhi and other serogroup D salmonellae among a total of 140 bacterial isolates representing eight different Enterobacteriaceae genera tested.

72 S. typhi strains collected in Guangdong were tested for their Vi II phage types and their antimicrobial susceptibilities. The result of Vi II phage typing showed that 62 strains could be divided into definite types. The result of antimicrobial susceptibilities showed that, as national standard reference strains, all the 72 local strains were susceptible to choloramphenical, gentamycin, neomycin and polymycin B and were of different resistance to other 14 antimicrobial agents. The resistant profiles of strains isolated in different ages shared no significant difference. Choloramphenical remains Commonally selectable to treat Typhoid.

A prospective study was conducted to better characterize the epidemiology of plasmid-bearing strains of Salmonella typhi in an endemic area of Lima, Peru, and to determine if plasmids were associated with specific manifestations of typhoid fever. Of 228 S. typhi isolated from patients at Cayetano Heredia University Hospital in Lima during 1987-1988, 76 (33%) contained plasmids. Ten different plasmid profiles were identified, with ten distinct plasmids present within these profiles. There was significant temporal clustering of isolates having common plasmid profiles. Two plasmids (both from the same isolate) carried antibiotic resistance genes. Two cryptic plasmids with approximate sizes of 55 and 65 kilobases (kb) appeared to be closely related, based on restriction endonuclease digestions and Southern blot analysis. An ampicillin resistance plasmid from a 1989 patient isolate differed by only a single restriction fragment from the cryptic 65-kb plasmid. No association was found between any plasmid or plasmid profile and severity or clinical manifestations of disease.

Several lines of evidence indicate a relatively low genetic heterogeneity in the natural Salmonella typhi population. However, some S. typhi isolates found in Indonesia express, instead of the usual fliC-d flagellin gene, a different flagellar gene fliC-j. In addition, Indonesian strains may have a second flagellar antigen fliC-z66. We have previously suggested, on the basis of the flagellar antigen constitution, that S. typhi evolved in an isolated human population in Indonesia. In order to test this hypothesis, we have gathered S. typhi isolates from around the world and tested the genetic heterogeneity among them. In general, polymorphism was greater in isolates from the Far East, as was indicated by Southern hybridizations with rDNA and fliC DNA probes. Gene fliC-j was not found in S. typhi isolates, other than those from Indonesia. However, the one-clone origin of S. typhi was indicated by a common DNA fingerprint pattern and by the occurrence, in the 5' end region of the fliC gene, of 10 scattered nucleotides that differ from the corresponding 10 nucleotides in other fliC alleles studied. These nucleotides were present in all isolates tested but did not change the amino acid sequence of the flagellin polypeptide.

We examined envelope protein profiles, chromosomal restriction endonuclease digest patterns, and immune responses to envelope proteins for collections of Salmonella typhi strains isolated in Peru and Indonesia. Only minor differences in envelope protein patterns were apparent among strains. Strains from 7 of 20 Indonesian patients had a distinct chromosomal digest pattern compared with patterns of Peruvian and other Indonesian strains. Strains with this pattern carried the gene for the j flagellar antigen (H1-j); differences in response to envelope proteins of j and d strains were noted on immunoblot analysis. Our data suggest that there are genotypic and phenotypic differences among S. typhi strains. The clinical importance of these differences remains to be fully evaluated; however, in this study it was not possible to show a clear correlation between strain characteristics and disease severity.

Eighty S. typhi strains isolated during the period of one year (July 1989 to June 1990) were tested for susceptibility to chloramphenicol, ampicillin, cotrimoxazole, gentamicin, kanamycin, cefazolin, furazolidone and ciprofloxacin. Determination of minimum inhibitory concentration (MIC) by tube dilution method showed that the multiply resistant S. typhi strains were resistant to chloramphenicol and ampicillin up to a concentration of 1000 micrograms/ml. MIC of sulphamethoxazole was found to be 800 micrograms/ml and trimethoprim 160 micrograms/ml. The presence of R plasmid was demonstrated by resistance transfer experiments using Esch. coli K12 (F-Lac+Nal-) as the recipient. On phage typing, most of the multiresistant S. typhi isolates were found to belong to phage type E1.

S. typhi was isolated from 241 patients of pyrexia between July 1990 and March 1991. Multiple drug resistance was observed in 220 (91.3%) strains, the commonest pattern of drug resistance being ACCoT (49.4%). Predominance of phage type E1 in 196 (81.3%) strains and biotype I in 225 (93.4%) strains was observed. All ACCoT strains belonged to phage type E1 and all strains of phage type E1 belonged to biotype I.

Characterization of 169 strains of Salmonella typhi of phage types C1, C4, D1 and D9 isolated in 1975-88 was carried out by rDNA gene restriction pattern analysis. Twenty-four isolates had been recovered during four large waterbone outbreaks in the last 20 years in Sicily; 145 strains, isolated from apparently sporadic cases of infection in Southern Italy in the same period of time, were also examined. Application of rRNA-DNA hybridization technique after digestion of chromosomal DNA with Cla I showed the identity of patterns of the epidemic strains of phage types C1 and D1, confirming attribution of the outbreaks to single bacterial clones. Patterns of the two available strains of lysotype D9 were slightly different, whilst the 12 epidemic strains of phage type C4 could be assigned to two distinct patterns scarcely related to each other and, consequently, to two different clones. A considerable heterogeneity was detected among all apparently sporadic isolates of the four phage types under study. This fingerprinting method appears a reliable tool to complement phage typing in characterizing isolates of S. typhi. In particular, epidemiological features of spread of this salmonella serovar in areas, where simultaneous circulation of indigenous and imported strains occurs, can be elucidated.

In combined media for primary identification Salmonella typhi are detectable by the lactose test only within a certain range of proteolytic activities, which fact is explained by specific features of these media. Reduced proteolytic activity and thiosulfate reductase activity in S. typhi cultures resulted in false-positive lactose test and false-positive hydrogen sulfide production test, this leading to identification of these cultures as Escherichia in accordance with the universally acknowledged classification scheme. Taking this feature into consideration, the author has additionally isolated 20 typical S. typhi strains of the 22 cultures isolated in the laboratory.

The biological properties of 106 S. typhi cultures were studied; of these, 59 cultures were isolated from 45 chronic carriers and 47 cultures, from 23 typhoid fever patients. According to the degree of their virulence (CPD50 in the continuous cell-line culture Hep-2), the strains isolated from the patients were more virulent than those isolated from the chronic carriers. The mean value of lg CPD50 was 5.76 +/- 0.04 for the patients and 6.86 +/- 0.03 for the chronic carriers. The strains isolated from the patients showed greater variability in the degree of their virulence. The study of the plasmid spectrum showed that 9.4 +/- 5.6% of the strains contained plasmids. From the patients plasmid-containing strains were isolated more frequently than from the carriers (14.9 +/- 2.5% and 5.1 +/- 2.9%). Multiresistance to antibiotics in combination with the presence of plasmids was detected in 6 strains isolated from the typhoid patients with morbidity having the character of outbreaks.

Two lactose-fermenting Salmonella typhi strains were isolated from bile and blood specimens of a typhoid fever patient who underwent a cholecystectomy due to cholelithiasis. One lactose-fermenting S. typhi strain was also isolated from a pus specimen which was obtained at the tip of the T-shaped tube withdrawn from the operative wound of the common bile duct of the patient. These three lactose-fermenting isolates: GIFU 11924 from bile, GIFU 11926 from pus, and GIFU 11927 from blood, were phenotypically identical to the type strain (GIFU 11801 = ATCC 19430 = NCTC 8385) of S. typhi, except that the three strains fermented lactose and failed to blacken the butt of Kligler iron agar or triple sugar iron agar medium. All three lactose-fermenting strains were resistant to chloramphenicol, ampicillin, sulfomethoxazole, trimethoprim, gentamicin, cephaloridine, and four other antimicrobial agents. The type strain was uniformly susceptible to these 10 drugs. The strain GIFU 11925, a lactose-negative dissociant from strain GIFU 11926, was also susceptible to these drugs, with the sole exception of chloramphenicol (minimal inhibitory concentration, 100 micrograms/ml).

The distribution of phage-types was studied among 434 strains of S. typhi from Bagdad, Amara and Bassora. Biotypes, colicinogeny, tetrathionate-reductase activity (TTR) and susceptibility to Salmonella phage O.I. were also studied. The most frequent phage-types in Irak were A, D1, E1 alpha, F1, M1, O, T, 46 and two other large groups of strains (I + IV and Vi degraded strains). Only 4.38% of S. typhi were TTR-; the strains of phage-type 53 were TTR+. Colicinogeny was demonstrated in 2.5% of S. typhi (lysotype 40, group I + IV and Vi degrades strains). All strains were lysed by Salmonella phage O.I, with the exception of three strains of phage-type T. Comparisons were made with the S. typhi phage-type in Iran and evidence was found for one regional epidemiological community in respect to the distribution of phage-types.

Pyrolysis-gas-liquid chromatography was used to differentiate selected species of Enterobacteriaceae. Individual cultures of Salmonella typhi, Hafnia alvei, and Proteus vulgaris, and 12 strains of Yersinia enterocolitica were grown in nutrient broth. After harvest and lyophilization, the bacterial samples were pyrolyzed at 900 degrees C, and their volatile fractions were separated on a 50-m capillary column coated with Carbowax 20M. The resulting pyrolysis elution patterns (pyrograms) of the four species were monitored on an integrating console, which was coupled with the chromatographic detector. The pyrograms were divided into 312 30-s time interval areas, and each interval area was normalized in relation to the area of the entire curve. The normalized areas were evaluated by stepwise linear discriminant analysis, and the discriminating component coordinates were used to generate a plot of the canonical variables. Distinct clustering patterns allowed discrimination among the four genera of Enterobacteriaceae studied. The tight clustering of the 12 Y. enterocolitica strains suggests the advantage of pyrolysis-gas-liquid chromatography over traditional approaches for species identification.

In 1978, after a party in a Cape Town suburb attended by several hundred people, 69 persons were treated for typhoid fever. The precise source of the infection could not be traced, although it is reasonable to suppose that food eaten at the party had been contaminated by the main caterer. All 57 cultures of Salmonella typhi phage-typed were of phage type 46, including that obtained from the stool of the main caterer, who was asymptomatic. An epidemiological profile of the cases and an account of the management of the outbreak is given. There were no deaths and no patient became a carrier. Although the outbreak was contained, certain problems relating thereto are aired, including in particular the potential hazard of food-borne disease wherever housing and environmental standards are low.

Thirteen strains of Salmonella typhi phage type A/Tan isolated in a typhoid endemic zone north to Lisbon (November 1977-June 1979) showed a low chloramphenicol resistance (MIC = 32 microgram/ml). None of these strains could transfer chloramphenicol resistance at 28 or 37 degrees C. Production of chloramphenicol-acetyl-transferase by these strains could not be demonstrated. No extrachromosomal DNA was detected by agarose-gel electrophoresis. A chromosomal resistance mechanism is postulated which could act on the permeation system.

In this work a total of 82 strains of Salmonella typhi were isolated from Egyptian patients diagnosed as quiry enteric fever. These cases were from Ismalia, Suez and port Said Areas. The strains fell in 16 phage types. Phage types N, 40, E1, and degraded Vi were the commonest phage type in Ismailia, while phage types degraded Vi and C1 were the commonest in Port Said. Phage types Di-N, degraded Vi, A and C1 were the commonest in Suez. Chemotyping of Salmonella typhi showed that the majority of the strains belonged to chemotype I (82%), and the rest belonged to chemotype II (18%). Colicin production was negative and all the strains were susceptible to the currently used antibiotics.

Two hundred forty-one strains of Salmonella typhii isolated in Lima, Peru, from October 1981 through February 1983 were tested for susceptibility to antimicrobial agents. Seventy-two strains (29.9%) were resistant to chloramphenicol and other antibiotics, including ampicillin, sulfonamides, and trimethoprim. The minimal inhibitory concentrations of 17 antimicrobial agents were determined for all of these chloramphenicol-resistant strains. Sch 25393, new beta-lactams, new quinolones, and the formulation clavulanic acid-amoxicillin were effective against all the strains. Four different resistance patterns distributed among eight phage types were observed. The 72 resistant S. typhi could transfer the resistance marker into Escherichia coli C1, and all the plasmids belonged to the incompatibility group H1.

The antibiotic sensitivity of 4095 Salmonella typhi strains isolated in Hungary from January, 1974 to June 1979, was tested. Twelve strains derived from one patient and seven chronic carriers were resistant to antibiotics due to R-plasmids. One of the S. typhi strains carried two R-plasmids and the change in the phage type of this strain was caused by one of the plasmids. R-plasmid of the same restrictive property was found in an Escherichia coli strain isolated from the faeces of the corresponding carrier. All of the R-plasmids examined were fi-, E. coli and Shigella flexneri phages were restricted by four R-plasmids, S. typhi phages were restricted by one. R-plasmids belonged to incompatibility groups I1, I2, W and H.

From 1974 through 1981, 4,089 isolates of Salmonella typhi were phage typed at the Centers for Disease Control and nine regional laboratories in the United States. The most prevalent types were degraded Vi (27%), E1 (20.6%), A (9.8%), C1 (5.7%), untypable Vi (3.5%), W form (3.5%), D1 (3.4%), B3 (3.4%), and F1 (2.4%). There were less than 2% of each of the remaining types. The distribution of phage types for this time period was similar to that seen in the periods 1966-1969 and 1970-1973, except that phage type B3 was one of the 10 most prevalent types in 1974-1981 but was not seen in 1966-1973. Phage typing is presently the most valuable laboratory tool for differentiation of strains of S. typhi in epidemiological studies.

In a survey of the nutritional requirements of Salmonella typhi it was found that 3.2% of 560 recent clinical isolates were able to grow in a minimal medium consisting of phosphates, ammonium and magnesium sulfates, and glucose; the remainder required tryptophan. Both groups grew slowly and rather poorly in these media due to a deficient utilization of sulfur from sulfate. Addition of cysteine or sodium sulfide or thiosulfate promoted rapid and profuse growth. Minimal medium containing thiosulfate as a source of sulfur allowed for an easy and sharp differentiation of prototrophic variants needing none of the amino acids, and tryptophan auxotrophs. The prototrophic phenotype is not the result of the presence of rare prototrophic mutants, since these strains were able to develop in minimal medium from very small inocula (10(2)), all colonies were prototrophic in replica plating experiments, and the cultures gave comparable colony counts when seeded simultaneously in nutrient and on minimal agar plates.

All the cases of HIV infected patients diagnosed in our department during 1987 of Salmonella bacteremia are included in this report. Out of a total of 10 patients with both conditions, six were diagnosed of AIDS, three of AIDS related complex, and one presented an asymptomatic HIV infection. The mean age was 32.9 years (range 22 to 56). Eight of them were males, seven were intravenous drug addicts, and three were homosexual. Fever was observed in all cases and diarrhea in four of them. Salmonella enteritidis was isolated from the blood culture of nine patients and salmonella typhimurium from one. Salmonella enteritidis was isolated from the stool culture of 5 patients and Salmonella typhimurium and Campylobacter from the stool culture of one patient. Of the 10 patients 6 have died, 4 of them within the three weeks after the diagnosis of Salmonella non-typhi bacteremia, 2 have not relapsed and two patients were lost during follow up.

To date, epidemiologic associations among strains of Salmonella typhi are based exclusively on phage typing, which may be of limited value if a common phage type is involved. Analysis of ribosomal RNA gene restriction patterns allows separation of most independently isolated strains of identical phage types. The sensitivity of the method is dependent on the restriction enzymes used to digest chromosomal DNA. It was highest for PstI, which separated 16 of 20 strains that belonged to 8 phage types including 3 untypable strains. Three strains differed in their phage types but had identical ribosomal RNA gene restriction patterns. Also, two pairs of strains indistinguishable by phage typing exhibited identical patterns; however, two of these strains were expected to be identical because they were isolated from two patients who were likely exposed to the same source. Ribosomal RNA gene restriction patterns appear to be stable. Thus, the method may complement phage typing and aid in further differentiation of strains.

Since periodical survey of the sewage entering the sewage-farm in Matsuyama City revealed a high incidence of Salmonella typhi of different phage types, attempts were made to trace the upstream reservoir. It was found that S. typhi was drained into a particular manhole at a distance of about 5 km from the sewage-farm. Two members of two families were found to be carriers. Further investigation detected other 25 carriers. The 27 carriers were all pupils of the same primary school. Ten of them showed mild symptoms such as fever, abdominal pain and diarrhea; the remaining 17 were asymptomatic. The phage type of 24 isolates was of Vi degraded approaching phage type A [degraded Vi(A)] and that of the other three was of type 53. The results coincided with those of the isolates from sewage.

In the period between 1.1.1974 and 31.12.1978 phage typing of 2058 strains of S. typhi and 1672 strains of S. paratyphi-B was carried out. 45 S. typhi phage types were found, 11 of these occurred in a frequency of more than 1% (relevant to foci). These were E1 a (21.6%), A (17.7%), F1 (5.8%), D1 (5.5%), C1 (4.6%), E1b (4.1%), D2 (2.5%), 40 (1.5%), 29 (1.3%), B2 (1.0%), 46 (1.0%). Among S. paratyphi-B strains 23 phage types or varieties were observed, 11 of these occurred in a frequency more than 1% (relevant to foci): Taunton (46.9%), 1 m.c. (7.8%), 3aI m.c. (7.7%), B.A.O.R. (6.5%), 3aI var. 1 (5.5%), Dundee (4.4%), 3a m.c. (3.0%), 3b m.c. (2.2%), Beccles m.c. (1.9%), Jersey (1.5%), 1 var. 1 (1.4%). In the year 1974 two epidemics of typhoid fever occurred, one with 417 cases (phage type A, subtype Tananarive) and the other with 41 cases (phage type E1a). In the year 1977 there was an outbreak of paratyphoid B fever with 53 cases (phage type 3aI var. 1). The increasing number of imported cases of typhoid and paratyphoid fever from other countries is remarkable. The age distribution of typhoid and paratyphoid bacilli carriers shows that persons who are older than 60 years represent the age group in which carriers occur most frequently.