[Epidemiology profil of fever typhoid in Meknes (Morocco) 2013-2016]

INTRODUCTION

Twenty million cases of typhoid and paratyphoid fever (TF) are observed annually worldwide with more than 200,000deaths. These fevers occur in areas where hygiene is precarious, mainly in developing countries. The objective of this study was to describe epidemiological patterns of TF in Meknes, Morocco in order to improve preventive measures.

METHODS

We conducted a case series study based on data from 2013 to 2016 in the Meknes TF surveillance system. Data collected included socio-demographic variables, place of residence, season, mode of water supply, and food consumed. Diagnosis of TF was confirmed with the Widal test. Data were analyzed with Epi-info version 7 and mapping was done with Qgis version 2.18.1.

RESULTS

Three hundred and twenty-two cases were reported with a male/female sex ratio of 0.9. Average age was 26±20years. Incidence increased from 13 per 100.000inhabitants in 2013 to 8 per 100.000 inhabitants in 2016. Two hundred and seventy-nine (87%) cases occurred in urban areas and 174 (54%) cases developed in summer. One death was recorded.

CONCLUSION

Public awareness campaigns on health education for hygiene are needed. Focus should be placed on transmission by food handlers.

Drug-resistant enteric fever worldwide, 1990 to 2018: a systematic review and meta-analysis

BACKGROUND

Antimicrobial resistance (AMR) is an increasing threat to global health. There are > 14 million cases of enteric fever every year and > 135,000 deaths. The disease is primarily controlled by antimicrobial treatment, but this is becoming increasingly difficult due to AMR. Our objectives were to assess the prevalence and geographic distribution of AMR in Salmonella enterica serovars Typhi and Paratyphi A infections globally, to evaluate the extent of the problem, and to facilitate the creation of geospatial maps of AMR prevalence to help targeted public health intervention.

METHODS

We performed a systematic review of the literature by searching seven databases for studies published between 1990 and 2018. We recategorised isolates to allow the analysis of fluoroquinolone resistance trends over the study period. The prevalence of multidrug resistance (MDR) and fluoroquinolone non-susceptibility (FQNS) in individual studies was illustrated by forest plots, and a random effects meta-analysis was performed, stratified by Global Burden of Disease (GBD) region and 5-year time period. Heterogeneity was assessed using the I2 statistics. We present a descriptive analysis of ceftriaxone and azithromycin resistance.

FINDINGS

We identified 4557 articles, of which 384, comprising 124,347 isolates (94,616 S. Typhi and 29,731 S. Paratyphi A) met the pre-specified inclusion criteria. The majority (276/384; 72%) of studies were from South Asia; 40 (10%) articles were identified from Sub-Saharan Africa. With the exception of MDR S. Typhi in South Asia, which declined between 1990 and 2018, and MDR S. Paratyphi A, which remained at low levels, resistance trends worsened for all antimicrobials in all regions. We identified several data gaps in Africa and the Middle East. Incomplete reporting of antimicrobial susceptibility testing (AST) and lack of quality assurance were identified.

INTERPRETATION

Drug-resistant enteric fever is widespread in low- and middle-income countries, and the situation is worsening. It is essential that public health and clinical measures, which include improvements in water quality and sanitation, the deployment of S. Typhi vaccination, and an informed choice of treatment are implemented. However, there is no licenced vaccine for S. Paratyphi A. The standardised reporting of AST data and rollout of external quality control assessment are urgently needed to facilitate evidence-based policy and practice.

TRIAL REGISTRATION

PROSPERO CRD42018029432.

Chain effects of clean water: The Mills-Reincke phenomenon in early 20th-century Japan

This study explores the validity of chain effects of clean water, which are known as the "Mills-Reincke phenomenon," in early 20-century Japan. Recent studies have reported that water purifications systems are responsible for huge contributions to human capital. Although some studies have investigated the instantaneous effects of water-supply systems in pre-war Japan, little is known about the chain effects of these systems. By analyzing city-level cause-specific mortality data from 1922 to 1940, we find that a decline in typhoid deaths by one per 1000 people decreased the risk of death due to non-waterborne diseases such as tuberculosis and pneumonia by 0.742-2.942 per 1000 people. Our finding suggests that the observed Mills-Reincke phenomenon could have resulted in the relatively rapid decline in the mortality rate in early 20-century Japan.

Immunogenicity, safety and reactogenicity of a Phase II trial of Vi-DT typhoid conjugate vaccine in healthy Filipino infants and toddlers: A preliminary report

BACKGROUND

Typhoid fever remains an important public health problem in developing countries and is endemic in many parts of Asia and Africa where the incidence of disease typically peaks in school-aged children. Age restrictions and other limitations of existing oral live-attenuated typhoid and parenteral Vi polysaccharide vaccines have triggered the development of Vi conjugate vaccines with improved immunological properties, use in younger age range, and longer durability of protection. We present the safety, reactogenicity, and immunogenicity data from a Phase II study after a single dose of Vi polysaccharide conjugated to diphtheria toxoid (Vi-DT) conducted in 6-23-month old Filipino children.

METHODS

This is a randomized, observer-blinded Phase II study to assess the immunogenicity, safety and reactogenicity of Vi-DT compared to placebo, conducted in Muntinlupa City, The Philippines. Participants aged 6-23 months were enrolled and randomized to Vi-DT (25 µg) or placebo (0.9% sodium chloride) and evaluated for immunogenicity and overall safety 28 days post vaccination.

RESULTS

A total of 285 participants were enrolled and age-stratified: 6 to < 9 months, 9-12 months, and 13-23 months. Seventy-six (76) participants received Vi-DT and 19 received placebo per each strata. All participants seroconverted after a single dose of Vi-DT versus 7% of placebo recipients. Anti-Vi IgG GMT was 444.38 [95% CI (400.28; 493.34)] after a single dose of Vi-DT; there was no change in GMT after placebo administration, 0.41 [95% CI (0.33; 0.51), p < 0.0001]. A similar pattern of immunogenicity was reported across all age strata. The vaccine reported to be safe and well tolerated.

CONCLUSIONS

Vi-DT vaccine was immunogenic, safe, and well tolerated in children aged 6-23 months. ClinicalTrials.gov registration number: NCT03527355.

Antioxidant activity of dichloromethane fraction of Dichrocephala integrifolia in Salmonella typhi-infected rats

OBJECTIVE

Infectious diseases such as typhoid fever lead to the formation of free radicals which can damage the body. Many medicinal plants have antioxidant molecules that neutralize free radicals. The present work evaluated the antioxidant activity and histopathological effects of the dichloromethane fraction of Dichrocephala integrifolia in Salmonella typhi-infected rats.

METHODS

The S. typhi-infected rats concurrently received daily doses of D. integrifolia extract at doses of 25, 50 and 100 mg/kg body weight or ciprofloxacin (5 mg/kg body weight) for 15 days. Body temperature was measured daily during infection and treatment periods. At the end of treatment period, the animals were sacrificed and biological responses including hematological parameters, superoxide dismutase and catalase activities, and glutathione, malondialdehyde and nitric oxide concentrations were evaluated.

RESULTS

The elevated body temperature induced by infection was significantly decreased in animals treated with 25, 50 or 100 mg/kg of the extract. Platelet levels decreased slightly in infected rats, while treatment with the dichloromethane fraction of D. integrifolia significantly increased platelet levels; this response was greater than that elicited by ciprofloxacin. The doses of 50 and 100 mg/kg of the dichloromethane fraction of D. integrifolia notably decreased monocyte and neutrophil values. Activity of superoxide dismutase and catalase and levels of glutathione in the tissues of treated animals were increased significantly (P < 0.01), while malondialdehyde and nitric oxide levels were significantly decreased (P < 0.01), following treatment with the dichloromethane fraction of D. integrifolia.

CONCLUSION

The results of this study show that the dichloromethane fraction of D. integrifolia has protective effects against a series of pathological conditions initiated by oxidation and tissue damage in the course of a S. typhi infection.

Ovarian abscess caused by Salmonella enterica serovar Typhi: a case report

Background

Typhoid fever is a human-specific disease caused by a bacterium, Salmonella enterica subspecies enterica serovar Typhi. It is transmitted through ingestion of contaminated food or water. It is mostly diagnosed by blood culture. Salmonella Typhi usually manifests as a febrile illness with bacteremia after initial entry through the gastrointestinal route, but it can occasionally cause significant disease in extraintestinal sites. We report a case of a girl in Fiji with a right ovarian abscess infected by Salmonella Typhi.

Case presentation

A 14-year-old iTaukei (indigenous Fijian) girl presented to our hospital with abdominal pain of 1 month’s duration. Two days prior to her admission, she developed high-grade fever and nausea and had one episode of vomiting. On presentation, she appeared unwell; she was tachycardic (116 beats per minute) and febrile (38.8 °C). Her abdominal examination revealed generalized tenderness. Other examination findings were normal. The provisional diagnosis of abdominal sepsis led to an emergency laparotomy during which an enlarged right ovary was found to be spontaneously discharging pus. The ovary was incised and drained, and the patient was commenced on intravenous ceftriaxone 1 g twice daily, cloxacillin 1 g four times daily, and metronidazole 500 mg three times daily. She recovered promptly and was discharged to home on the sixth postoperative day. The purulent material from the ovary grew Salmonella Typhi.

Conclusion

Extraintestinal infections caused by Salmonella Typhi are rare but can cause severe and life-threatening disease. Our patient had a prolonged history of abdominal pain and was found to have a ruptured right ovarian abscess due to Salmonella Typhi. Ovarian abscesses in girls who are not sexually active are not associated with pelvic inflammatory disease and suggest local or hematogenous spread. This case report may increase health workers awareness to include common and endemic infections in the differential diagnosis of unusual clinical presentations to help the initiation of appropriate investigation and management as quickly as possible.

Population structure and transmission modes of indigenous typhoid in Taiwan

BACKGROUND

Indigenous typhoid fever was continuing to be identified in Taiwan which has not been endemic for the enteric fever for more than 20 years. The source and transmission by which the local patients acquired typhoid and the population structure of the indigenous typhoid strains remain not well characterized.

METHODS

During 2001 and 2014, non-duplicated clinical Salmonella enterica serovar Typhi isolates in a hospital were analyzed by whole-genome sequencing (WGS) and determined for pulsotypes. Maximum likelihood phylogeny was constructed by nucleotide alterations in core genomes and compared to the framework of global typhoid strains. Potential source and transmission were traced by correlating the phylogeny and the temporal relationship between isolates.

RESULTS

A total of 43 S. Typhi isolates from indigenous cases were analyzed and a majority (39, 90.7%) of them were belonged to six WGS-defined genotypes prevailing mainly in Southeast Asia. Genotype 3.4.0 and a multidrug-resistant type 4.3.1 (also known as pandemic H58 haplotype) were associated respectively with two solitary small-scale outbreaks, implying a transmission mode of importation followed by outbreak. Twelve isolates with nearly identical core genomes were belonged to genotype 3.2.1 but were categorized into three different pulsotypes. The 3.2.1 isolates were identified across 13 years and involved in three clusters and a sporadic case, indicating sustained local transmission of the same strain. The remaining indigenous isolates belonging to three genotypes (2.1, 3.1.2, and 3.0.0) were of substantial genetic diversity and isolated at different time points, indicating independent event of each case.

CONCLUSIONS

Indigenous typhoid in Taiwan occurred mainly with the forms of small-scale outbreaks or sporadic events likely by contracting imported strains which prevailed in Southeast Asia. Sustained local transmission of certain strain was also evident by WGS analysis, but not by conventional pulsotyping, highlighting the importance of continuing molecular surveillance of typhoid fever with adequate tools in the non-endemic region.

Analysis of isolates from Bangladesh highlights multiple ways to carry resistance genes in Salmonella Typhi

Background

Typhoid fever, caused by Salmonella Typhi, follows a fecal-oral transmission route and is a major global public health concern, especially in developing countries like Bangladesh. Increasing emergence of antimicrobial resistance (AMR) is a serious issue; the list of treatments for typhoid fever is ever-decreasing. In addition to IncHI1-type plasmids, Salmonella genomic island (SGI) 11 has been reported to carry AMR genes. Although reports suggest a recent reduction in multidrug resistance (MDR) in the Indian subcontinent, the corresponding genomic changes in the background are unknown.

Results

Here, we assembled and annotated complete closed chromosomes and plasmids for 73 S. Typhi isolates using short-length Illumina reads. S. Typhi had an open pan-genome, and the core genome was smaller than previously reported. Considering AMR genes, we identified five variants of SGI11, including the previously reported reference sequence. Five plasmids were identified, including the new plasmids pK91 and pK43; pK43and pHCM2 were not related to AMR. The pHCM1, pPRJEB21992 and pK91 plasmids carried AMR genes and, along with the SGI11 variants, were responsible for resistance phenotypes. pK91 also contained qnr genes, conferred high ciprofloxacin resistance and was related to the H58-sublineage Bdq, which shows the same phenotype. The presence of plasmids (pHCM1 and pK91) and SGI11 were linked to two H58-lineages, Ia and Bd. Loss of plasmids and integration of resistance genes in genomic islands could contribute to the fitness advantage of lineage Ia isolates.

Conclusions

Such events may explain why lineage Ia is globally widespread, while the Bd lineage is locally restricted. Further studies are required to understand how these S. Typhi AMR elements spread and generate new variants. Preventive measures such as vaccination programs should also be considered in endemic countries; such initiatives could potentially reduce the spread of AMR.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5916-6) contains supplementary material, which is available to authorized users.

Serodiagnostic evaluation of recombinant CdtB of S. Typhi as a potential candidate for acute typhoid

Typhoid fever caused by human restricted Salmonella typhi presents a considerable health burden on developing South-Asian nations like India. The suboptimal sensitivity and specificity associated with culture-based isolation of etiological agent and the extensively used surface antigen-based serological assays often lead to misdiagnosis and inappropriate antimicrobial treatment. The increasing reports of the emergence of resistant strains and undefined disease burden signify the critical need for an inexpensive, reliable, easy-to-use, and highly sensitive diagnostic test for typhoid fever. Utilizing S. typhi-specific and immunogenic antigens in sero-diagnostic assays could lead to precise diagnosis of acute typhoid and prompt treatment. In this study, we report cloning, expression, and purification of recombinant Cytolethal distending toxin subunit B (CdtB) of S. typhi, which is reported to be highly specific, immunogenic, and expressed only upon S. typhi infection. We further evaluated the purified recombinant CdtB for its diagnostic potential in an IgM-based indirect ELISA format using 33 human samples. Twenty-one serum samples from blood culture confirmed cases (n = 21) of typhoid and 12 samples from healthy controls (n = 12) were tested. The assay showed sensitivity of 100% and specificity of 83.3% respectively with positive and negative predictive values of 91.3 and 100% respectively. Efficient detection of specific IgM antibodies indicates that CdtB could be highly valuable in sero-diagnosis of acute typhoid and rapid screening of clinical samples.

In vitro characterization and preclinical immunogenicity of Typhax, a typhoid fever protein capsular matrix vaccine candidate

Typhax is an investigational typhoid fever vaccine candidate that was GMP manufactured applying Protein Capsular Matrix Vaccine (PCMV) technology. It consists of Vi polysaccharide antigen, derived from S. Typhi, non-covalently entrapped in a glutaraldehyde catalyzed cross-linked α-poly-L-lysine and CRM197 protein matrix. Analysis of Typhax determined the average molecular weight of the vaccine particles was approximately 6 x 10⁶ Daltons, corresponding to particles containing 1-2 molecules of Vi polysaccharide and 10-20 molecules of CRM197 protein. The ratio of the concentration of Vi to CRM197 protein in Typhax is 2.4:1. Preclinical immunogenicity studies in mice demonstrated that Typhax was immunogenic and elicited a significant increase in anti-Vi IgG antibody titers following each immunization. The anti-Vi IgG antibody response elicited by Typhax in rabbits increased as the dose increased from 0.1 µg to 2.5 µg. Further, at the 2.5 and 10 µg dose levels, the anti-Vi IgG antibody titers increased after the second and third immunizations. At the 10 µg dose level, 100% of rabbits seroconverted. In the non-human primate (NHP) study, 100% seroconversion was observed at both 2.5 µg and 10 µg dose levels after the first immunization. A murine in vivo immunopotency study demonstrated that Typhax stored at 4°C was stable for at least 30 months. Collectively, the Typhax in vitro profile, preclinical immunogenicity studies, and rabbit toxicology study indicate that Typhax is a viable typhoid fever vaccine candidate for Phase 1 clinical trial evaluation.

Loop-mediated isothermal amplification-based detection of typhoid fever on an automated Genie II Mk2 system - A case-control-based approach

Typhoid fever, caused by the bacterium Salmonella enterica subsp. enterica serovar Typhi, is an important cause of blood stream infections in the tropics, for which easy-to-apply molecular diagnostic approaches are desirable. The diagnostic performance of a newly introduced and a previously described loop-mediated isothermal amplification (LAMP) approach using different primer sets on a Genie II Mk2 device for the identification of Salmonella enterica ssp. enterica ser. Typhi was evaluated with well-characterized residual materials from the tropics in a case control-based approach. After in-vitro confirmation of binding characteristics of both LAMP primer sets with culture isolates (n = 112), sensitivity and specificity were 100% for the newly designed new LAMP primer set 1 with incubated blood culture materials, while specificity was reduced to 97.1% for primer set 2. For 170 EDTA blood samples, sensitivity and specificity were 10% and 98.3% for primer set 1 as well as 38.0% and 83.3% for primer set 2, respectively; qPCR from EDTA blood did not score much better with 10% sensitivity and 100% specificity. LAMP using a Genie II Mk2 device is suitable for the identification of Salmonella enterica spp. enterica ser. Typhi from incubated blood culture materials. Sensitivity and specificity were insufficient for diagnosis directly from EDTA blood samples but LAMP showed similar sensitivity as qPCR.

Raman spectroscopy based differentiation of typhoid and dengue fever in infected human sera

This study investigated the potential of Raman spectroscopy, to differentiate between two different types of human pathological conditions with some symptom similarity; typhoid and dengue. Raman spectra were recorded from 20 Salmonella Typhi infected and 22 dengue virus (DENV) infected sera samples using laser wavelength 785 nm. When Raman spectrum (540 to 1830 cm^-1) of serum samples was compared it showed significant variations. Twelve characteristic Raman bands at 562, 649, 716, 780, 838, 1099, 1144, 1156, 1260, 1386, 1556 and 1746 cm^-1 were recorded specifically in case of the typhoid infected samples, whereas four Raman bands at 756, 1218, 1672 and 1686 cm^-1 were found specifically in the DENV infected samples. For statistical differentiation principal component analysis (PCA) and linear discriminant analysis (LDA) was applied which successfully separated two sets of data. These disease specific Raman signatures may be labeled as biomarkers for identification as well as differential diagnosis of typhoid and dengue infection. Hence we propose that Raman spectroscopy has the potential to not only identify but also to differentiate between different pathological conditions, having some similar symptoms like high grade fever in this case.

Typhoid fever in the Czech Republic and an imported case after return from the Rainbow Gathering in Italy

Typhoid fever is a disease caused by the highly virulent bacterium Salmonella Typhi. It is transmitted by the oral-faecal route. In the Czech Republic, 53 cases of typhoid fever were reported in 1997-2017. Only seven of these cases were autochthonous. In August 2017, an imported case of typhoid fever was recorded in a 25-year-old unvaccinated woman who participated in the Rainbow Gathering in Italy one week prior to the onset of the disease. During her stay in Italy, she slept in a tent, ate her own food, and drank unboiled water. Presenting with persisting cough, tiredness, muscle and joint pain, and fever up to 40 °C after her return, she was admitted to the T&#345;ebí&#269; Hospital where she was diagnosed with S. Typhi. The epidemiological investigation identified six contacts. On discharge from hospital and at follow-up, the patient was tested negative. None of the contacts became ill.

Jejunal multiple perforations for combined abdominal typhoid fever and miliary peritoneal tuberculosis

Typhoid fever and tuberculosis, considered rare diseases in western countries, is still considered a notable problem of health issue in developing countries. The gastrointestinal manifestations of typhoid fever are the most common and the typhoid intestinal perforation (TIP) is considered the most dangerous complication. Abdominal localization of tuberculosis is the 6^th most frequent site for extra pulmonary involvement, it can involve any part of the digestive system, including peritoneum, causing miliary peritoneal tuberculosis (MPT). This is the case report of a 4 years old girl with multiple jejunal perforations in a setting of contemporary miliary peritoneal tuberculosis and typhoid fever occurred in "Hopital Saint Jean de Dieu" in Tanguietà, north of Benin. The patient was admitted in the emergency department with an acute abdomen and suspect of intestinal perforation, in very bad clinical conditions, underwent emergency laparotomy. The finding was a multiple perforations of the jejunum in a setting of combined abdominal typhoid fever and miliary peritoneal tuberculosis. Typhoid intestinal perforations and peritoneal tuberculosis are a very rare cause of non-traumatic peritonitis in western country, but still common in developing country. Considering the modern migratory flux and the diffusion of volunteer missions all around the world, the western surgeon should know this pathological entities, and the best treatments available, well known by surgeons with experience of working in developing countries. The combination of both TIP and MPT in the same patient, is a very rare finding which can worsen the outcome of the patient itself.

[CME: Typhoid Fever - Clinical Manifestation, Diagnosis, Therapy and Prevention]

CME: Typhoid Fever - Clinical Manifestation, Diagnosis, Therapy and Prevention Abstract. Thypoid fever is rare in Western countries. It is, however, among the most common etiologies for febrile illness in the traveller returning from tropical areas (especially South(east) Asia and Sub-Saharan Africa). There are several signs that have been described as classical findings in typhoid fever: i) febrile temperatures with relative bradycardia, ii) eosinopenia, iii) slow defervescence, and iv) systemic manifestations (e.g. hepatitis). Diagnosis is confirmed by positive blood cultures. Pretravel vaccination and safe food and water practices can prevent typhoid fever.

Management of Typhoid Fever - Clinical and Historical Perspectives in Korea

Typhoid fever, showed a dramatic decrease in its incidence from 56 per 100,000 population just after Korea's independence to <1 per 100,000 population in 2000s. The clinical features of patients with typhoid fever in Korea were not too different from those reported in textbooks. Beyond cultures and Widal test, other diagnostic techniques such as string capsule culture and polymerase chain reaction have been tried in Korea. As chloramphenicol is not used anymore in Korea, ampicillin, cotrimoxazole, fluoroquinolones, and third-generation cephalosporins have been administered for therapy of typhoid fever. Especially, ciprofloxacin and ceftriaxone were successfully tried with shorter duration of treatment (1 week). However, cases of treatment failure and resistance in ciprofloxacin were reported in Korea, which requires a great caution. As preventive vaccines, parenteral Vi polysaccharide vaccine and oral live attenuated vaccine are mainly used in Korea. The decline in the number of chronic carriers of typhoid fever in Korea by the roles of doctors and patient management from the health care authorities such as Korea Centers for Diseases Control and Prevention, prescription of effective antimicrobial agents, and increased piped water supply ratio are considered to be the major contributing factors to the reduction in the outbreak of typhoid fever in Korea.

Salmonella enterica serovar Typhi osteomyelitis in a young adult with sickle cell and thalassemia traits: A possible association

Salmonella osteomyelitis is known to occur in immunocompromised and sickle cell disease patients. It rarely occurs in other hosts. We present a case of chronic femoral osteomyelitis due to S. enterica serovar Typhi seen in a Maryland resident. Potential risk factors included traveling to an endemic area as well as a newly diagnosed sickle cell trait and thalassemia trait. It is postulated that less severe hemoglobinopathies may also contribute to an elevated risk of Salmonella osteomyelitis.

Association between floods and typhoid fever in Yongzhou, China: Effects and vulnerable groups

BACKGROUND

Little information about the effects of floods on typhoid fever is available in previous studies. This study aimed to examine the relationships between floods and typhoid fever and to identify the vulnerable groups in Yongzhou, China.

METHODS

Weekly typhoid fever data, flood data and meteorological data during the flood season (April to September) from 2005 to 2012 were collected for this study. A Poisson generalized linear model combined with a distributed lag non-linear model was conducted to quantify the lagged and cumulative effects of floods on typhoid fever, considering the confounding effects of long-term trend, seasonality, and meteorological variables. The model was also used to calculate risk ratios of floods for weekly typhoid fever cases among various subpopulations.

RESULTS

After adjusting for long-term trend, seasonality, and meteorological variables, floods were associated with an increased number of typhoid fever cases with a risk ratio of 1.46 (95% CI: 1.10-1.92) at 1-week lag and a cumulative risk ratio of 1.76 (95% CI: 1.21-2.57) at lag 0-1 weeks. Males, people aged 0-4 years old, people aged 15-64 years old, farmers, and children appeared to be more vulnerable than the others.

CONCLUSIONS

Our study indicates that floods could significantly increase the risks of typhoid fever with lag effects of 1 week in the study areas. Precautionary measures should be taken with a focus on the identified vulnerable groups in order to control the transmission of typhoid fever associated with floods.

Microbiological features of indigenous typhoid cases in Taiwan and relatedness to imported cases, 2001-2014: A cross-sectional analysis

BACKGROUND

Typhoid fever was rare in Taiwan but approximately two-thirds of the cases were indigenous. The transmission source of the indigenous cases and the relatedness to the imported cases remained unknown.

METHODS

Patients with any site culture positive for Salmonella enterica serovar Typhi were identified in a teaching hospital during 2001-2014. The isolates were determined for antibiotic susceptibilities, pulsed-field gel electrophoresis (PFGE) types and single nucleotide polymorphisms (SNP) types.

RESULTS

A total of 64 typhoid episodes were identified in 63 patients. Seventeen episodes (26.6%) were imported and a majority (10, 58.8%) of them were from Indonesia. The clinical manifestations, outcomes of patients and antibiograms of isolates were similar between indigenous and imported cases. 63.3% of the isolates were ciprofloxacin-resistant. The distributions of PFGE and SNP types did not differ significantly between indigenous and imported isolates, either (P = 0.191 and 0.124, respectively). Identical PFGE pattern could be identified in indigenous isolates appearing at certain time frames, indicating outbreaks due to local transmission of certain Typhi strains.

CONCLUSIONS

The imported cases of typhoid fever from Southeast Asia were the major sources of indigenous S. Typhi infections in Taiwan. Small-scale outbreaks occurred due to local transmission of the strains after their importation.

Typhoid fever: clinical presentation and associated factors in febrile patients visiting Shashemene Referral Hospital, southern Ethiopia

Objective

Although typhoid fever is a major public health problem in Ethiopia, data is not available in the study area. Therefore, this study aimed to determine the prevalence, clinical presentation at the time of diagnosis and associated factors of typhoid fever among febrile patients visiting Shashemene Referral Hospital, southern Ethiopia. A cross-sectional study was conducted from January 1, 2016, to October 30, 2016. Socio-demographic and clinical data were collected using a structured questionnaire. A blood sample was collected and inoculated into Tryptic soy broth.

Results

A total of 421 adult febrile patients suspected of typhoid fever were included in the study. Of these, the overall prevalence of culture-confirmed typhoid fever was 5.0% (21/421). The prevalence of typhoid fever was significantly associated with rural residence (8.4%). As compared to the urban resident, the rural resident was 3.6 times more likely found to have culture-confirmed typhoid fever. The prevalence of typhoid fever was significantly associated with those patients whose water source was spring 7 (12.3%) and river 7 (13.2%). All of those study participants who used treated water were culture negative. Fever for ≥ 5 days, abdominal pain, and skin rash independently predicted blood culture-confirmed typhoid fever.

Typhoid fever causing haemophagocytic lymphohistiocytosis in a non-endemic country - first case report and review of the current literature

INTRODUCTION

Development of secondary haemophagocytic lymphohistiocytosis (sHLH) in the context of typhoid fever (TF) is a very rare but serious complication.

METHODS

Description of the first pediatric case of typhoid fever acquired in a non-endemic area complicated by sHLH. A systematic literature review of sHLH in the context of TF was performed with extraction of epidemiological, clinical and laboratory data.

RESULTS

The literature search revealed 17 articles (22 patients). Fifteen patients were eligible for data analysis (53.4% children). All patients had fever and pancytopenia. Transaminases and LDH were frequently elevated (46.6%). Salmonella typhi was detected mainly by blood culture (64.3%). All the patients received antibiotics whereas immunomodulation (dexamethasone) was used in two cases.

CONCLUSIONS

A high suspicion index for this condition is needed even in non-endemic areas. The addition of immunmodulation to standard antimicrobial therapy should be considered in selected cases.

Estimating the incidence of enteric fever in children in India: a multi-site, active fever surveillance of pediatric cohorts

Background

Salmonella Typhi is responsible for about 20 million episodes of illness and over 140,000 deaths annually globally. South Asia has the highest documented burden of typhoid and is home to the multi-drug resistant H58 strain that makes treatment more challenging. The WHO recommends the use of Typhoid Conjugate Vaccines in typhoid endemic countries. Decisions on the preferred immunization strategy should be based on an analysis of disease burden, availability, affordability, and operational feasibility. Typhoid vaccines have so far remained unimplemented as public health measures because of a perceived decline in typhoid burden in recent years. The apparent decline, based on hospital reports, may be a result of rampant antimicrobial use in the community and therefore estimation of disease incidence at the community is necessary to better measure disease incidence and transmission.

Methods

Age-specific incidence of typhoid fever in children between 6 months and 15 years will be estimated in four community based cohorts in varied settings across India using standardized protocols for active fever surveillance in the community. Data will be collected on secured cloud infrastructure using a combination of android and web-based real-time data collection tools. Blood cultures will be done for children with fever lasting 3 or more consecutive days using automated blood culture systems. Those with blood-culture confirmed typhoid fever will be followed up till 90 days to estimate costs and clinical outcomes of the illness episodes. Environmental factors, access to safe water, sanitation, hygiene, food hygiene, demography, population density and socioeconomic status will be assessed periodically to characterise risk factors and permit extrapolation of burden to similar risk settings.

Discussion

With the availability of licensed typhoid conjugated vaccines in India, it is important to consider whether the burden of disease is present and sufficient to require the use of vaccine in addition to other interventions. Active case finding in the community permits the detection of cases that would be missed in facility-based surveillance systems. Understanding the age distribution, burden, cost-of-illness and transmission of disease is essential to plan interventions and predict their potential impact.

Trial registration

The surveillance has been prospectively registered in the Clinical Trial Registry of India (CTRI/2017/09/009719) on 12 September 2017.

Salmonella Typhi Colonization Provokes Extensive Transcriptional Changes Aimed at Evading Host Mucosal Immune Defense During Early Infection of Human Intestinal Tissue

Commensal microorganisms influence a variety of host functions in the gut, including immune response, glucose homeostasis, metabolic pathways and oxidative stress, among others. This study describes how Salmonella Typhi, the pathogen responsible for typhoid fever, uses similar strategies to escape immune defense responses and survive within its human host. To elucidate the early mechanisms of typhoid fever, we performed studies using healthy human intestinal tissue samples and "mini-guts," organoids grown from intestinal tissue taken from biopsy specimens. We analyzed gene expression changes in human intestinal specimens and bacterial cells both separately and after colonization. Our results showed mechanistic strategies that S. Typhi uses to rearrange the cellular machinery of the host cytoskeleton to successfully invade the intestinal epithelium, promote polarized cytokine release and evade immune system activation by downregulating genes involved in antigen sampling and presentation during infection. This work adds novel information regarding S. Typhi infection pathogenesis in humans, by replicating work shown in traditional cell models, and providing new data that can be applied to future vaccine development strategies.

[Diagnostic protocol for imported febrile syndrome]

In this protocol we shall set out the steps to follow in the clinical assessment of the patient with fever and where there is an epidemiological history of travel to tropical or subtropical areas. This is not intended to be exhaustive, but as a guide to doctors in their initial diagnostic approach to the patient who has come from the tropics consulting with a fever in the Emergency Department or the hospital ward. Differential diagnosis should be approached first and foremost on the basis of excluding malaria, but haemorrhagic fevers, rickettsiosis, typhoid fever and many other infections, some that are unique to tropical areas, and others that are cosmopolitan but more prevalent in such areas should also be taken into account.

Typhoid Fever Diagnosis in Endemic Countries: A Clog in the Wheel of Progress?

Typhoid fever causes significant morbidity and mortality in developing countries, with inaccurate estimates in some countries affected, especially those situated in Sub-Saharan Africa. Disease burden assessment is limited by lack of a high degree of sensitivity and specificity by many current rapid diagnostic tests. Some of the new technologies, such as PCR and proteomics, may also be useful but are difficult for low-resource settings to apply as point-of-care diagnostics. Weak laboratory surveillance systems may also contribute to the spread of multidrug resistant Salmonella serovar Typhi across endemic areas. In addition, most typhoid-endemic countries employ serological tests that have low sensitivity and specificity making diagnosis unreliable. Here we review currently available typhoid fever diagnostics, and advances in serodiagnosis of S. Typhi.

Development of a bivalent conjugate vaccine candidate against malaria transmission and typhoid fever

Immune responses to poorly immunogenic antigens, such as polysaccharides, can be enhanced by conjugation to carriers. Our previous studies indicate that conjugation to Vi polysaccharide of Salmonella Typhi may also enhance immunogenicity of some protein carriers. We therefore explored the possibility of generating a bivalent vaccine against Plasmodium falciparum malaria and typhoid fever, which are co-endemic in many parts of the world, by conjugating Vi polysaccharide, an approved antigen in typhoid vaccine, to Pfs25, a malaria transmission blocking vaccine antigen in clinical trials. Vi-Pfs25 conjugates induced strong immune responses against both Vi and Pfs25 in mice, whereas the unconjugated antigens are poorly immunogenic. Functional assays of immune sera revealed potent transmission blocking activity mediated by anti-Pfs25 antibody and serum bactericidal activity due to anti-Vi antibody. Pfs25 conjugation to Vi modified the IgG isotype distribution of antisera, inducing a Th2 polarized immune response against Vi antigen. This conjugate may be further developed as a bivalent vaccine to concurrently target malaria and typhoid fever.

Determinants of postoperative morbidity and mortality in children managed for typhoid intestinal perforation in Kano Nigeria

BACKGROUND

Intestinal perforation is a serious but poorly understood complication of typhoid fever. This study aims to determine the patient factors associated with postoperative morbidity and mortality.

METHODS

We retrospectively reviewed the records of all children presenting to our unit with typhoid intestinal perforation (TIP) between March 2009 and December 2013. The patients were grouped based on postoperative outcome status and were compared with respect to patient related variables, using chi square test. Multivariate analysis was performed using a binary logistic regression model. Significance was assigned to a p-value <0.05.

RESULTS

The records of 129 children were analyzed. There were 78 (60.5%) boys and 51 (39.5%) girls. The male/female ratio was 1.53:1. Their ages ranged from 3years to 13years (mean 8.14years; SD 2.61years). A single intestinal perforation was seen in 73.4% (94/128) of them, while 26.6% (34/128) had two or more. Mortality rate was 10.9%. Multivariate analysis showed that multiple intestinal perforations significantly predicted postoperative mortality (p=0.005) and development of postoperative fecal fistula (p=0.013), while serum albumin <32g/L was a predictor of postoperative surgical site infection (p=0.002).

CONCLUSION

Multiple intestinal perforations, a postoperative fecal fistula and hypoalbuminemia adversely affected outcome in our patients.

LEVEL OF EVIDENCE

III (Retrospective study). Type of study-Prognosis study.

[Epidemiological characteristics and molecular typing of typhoid and paratyphoid in China, 2009-2013]

Objective: To understand the epidemiological and molecular characteristics of typhoid and paratyphoid in China from 2009 to 2013, and provide evidence for the prevention and control of typhoid and paratyphoid, the development and improvement of surveillance strategies. Methods: Epidemiological analysis was conducted on the incidence data of typhoid and paratyphoid, and related public health emergencies in China during 2009-2013. Pathogen isolation and culture, serologic test were conducted for the typhoid and paratyphoid cases from 13 national surveillance sites. The isolates were subjected to antimicrobial susceptibility testing. Pulsed-field gel electrophoresis (PFGE) was performed for the molecular typing of these isolates. Results: The average incidence of typhoid and paratyphoid in China during this period was 1.03/100 000. The reported case number and incidence decreased with year. The provinces reporting high case numbers were Yunnan, Guizhou, Guangxi, Hunan, Zhejiang, Guangdong and Xinjiang. The incidence of age group 0-4 years was highest. The proportion of farmers and children outside child care settings showed an increasing tendency over time. The annual incidence peak was during July-August. Twenty five outbreaks occurred during 2009-2013. The results of pathogen isolation and culture showed that the positive rate was 3.00% (940/31 322), among the positive isolates, the proportion of Salmonella paratyphi A accounted for higher proportion (68.19%, 641/940) compared with Salmonella typhi (31.60%, 297/940). The drug resistances of Salmonella typhi and Salmonella paratyphi varied, but their resistances to nalidixic acid were highest (50.22% and 85.33%) respectively. A certain amount of Salmonella typhi isolates showed the resistance to the 3rd generation cephalosporins. PFGE analysis showed divergent patterns of Salmonella typhi compared with limited patterns of Salmonella paratyphi A. Conclusion: The epidemic level of typhoid and paratyphoid in China was relatively low, but the outbreak occurred occasionally. It is necessary to enhance the laboratory-based surveillance, particularly the capability of etiological diagnosis, outbreak investigation, response and antibiotic resistance monitoring, and conduct risk factor investigation in provinces with high incidences in recent years.

typhi (NARST) era in South India

The epidemiology of typhoid fever in South Asia has changed. Multi-drug resistant (MDR) Salmonella typhi ( S. typhi) is now frequently resistant to nalidixic acid and thus labelled NARST. Treatment failure with the use of fluoroquinolones has been widely noted, forcing clinicians to adopt alternative treatment strategies. In this observational study, we looked at various treatment regimens and correlated clinical and microbiological outcomes. In 146 hospitalised adults, the median minimum inhibitory concentration (MIC) for ciprofloxacin was 0.38 µg/mL with a median fever clearance time (FCT) of eight days (range = 2-35 days). Of the regimens used, gatifloxacin and azithromycin had a shorter FCT of six days compared to ceftriaxone (ten days; P < 0.001). Though mortality and relapse in our cohort was low, NARST seemed to correlate with mortality ( P = 0.006). Gatifloxacin or azithromycin clearly emerge as the drugs of choice for treatment of typhoid in South India.

Baseline Widal Titer Among Healthy Adult Males from the Greater Mymensingh Division of Bangladesh

BACKGROUND

Widal test is the most widely used laboratory investigation for diagnosis of typhoid. However, the test interpretation remains controversial in the context of endemic regions such as Bangladesh, as agglutination occurs at varied titrations among a large percentage of healthy population. Paired Widal tests are often not feasible; hence single unpaired test has to be used for screening, diagnosis and treatment.

OBJECTIVE

We aimed to assess the normal range of baseline titre for Anti TO, TH, AO, AH, BO agglutinins among healthy population in an endemic country with a view to guide the researchers and the clinicians, facilitating further investigation on updating cut off points of single Widal test for screening and diagnosis of typhoid fever in the context of Bangladesh.

METHODS

A cross-sectional study was carried out in Mymensingh Medical College, Bangladesh on 2925 male immigration applicants. A single blood sample was collected for Widal test and interpreted using standard guidelines.

RESULTS

The highest baseline titer for Anti TO, TH, AO, AH, BO agglutinins among 95% of the healthy participants was found to be 1:80 for each respectively. A titre of 1: 40 was observed for BH antigen.

CONCLUSION

In case of singular Widal test, baseline values for the normal range was found to be 1:20 - 1:80 for all the antigens (TO, TH, AO, AH, BO, BH), except BH, for which it was 1:20-1:40. Further studies, inclusive of other sociodemographic groups and positive controls are required to determine the updated cut off values.

Development of a synthetic Vi polysaccharide vaccine for typhoid fever

Typhoid fever remains a serious public health problem with a high impact on toddlers and young children. Vaccines against the Vi capsular polysaccharide are efficacious against typhoid fever demonstrating that antibodies against Vi confer protection. The currently licensed Vi typhoid vaccines have however limited efficacy and are manufactured by a complex process from wild-type bacteria. Due to these inherent issues with the current vaccines, an alternative vaccine based on an O-acetylated high molecular weight (HMW) polygalacturonic acid (GelSite-OAc™) was generated. The HMW polygalacturonic acid shares the same backbone as the Vi polysaccharide of Salmonella Typhi. The GelSite-OAc™ has a high molecular weight (>1 × 106 Da) and a high degree of O-acetylation (DOAc) (>5 μmole/mg), both exceeding the potency specifications of the current Vi vaccine. Studies in Balb/c mice demonstrated that GelSite-OAc™ was highly immunogenic, inducing a strong antigen-specific antibody response in a DOAc- and dose-dependent manner which was comparable to or higher than those induced by the licensed Vi vaccine. Importantly, the GelSite-OAc™ was shown to be fully protective in mice against lethal challenge with Salmonella Typhi. Furthermore, the GelSite-OAc™ demonstrated a boosting effect or memory response, exhibiting a >2-fold increase in antibody levels upon the second immunization with either GelSite-OAc™ or the Vi vaccine. This novel boosting effect is unique among polysaccharide antigens and potentially makes GelSite-OAc™ effective in people under 2 years old. Together these results suggest that the GelSite-OAc™ could be a highly effective vaccine against Salmonella Typhi.

Localised transmission hotspots of a typhoid fever outbreak in the Democratic Republic of Congo

Introduction

In a semi-urban setting in the Democratic Republic of Congo, this study aims to understand the dynamic of a typhoid fever (TF) outbreak and to assess: a) the existence of hot spots for TF transmission and b) the difference between typhoid cases identified within those hot spots and the general population in relation to socio-demographic characteristics, sanitation practice, and sources of drinking water.

Methods

This was a retrospective analysis of TF outbreaks in 2011 in Kikwit, DRC using microbiological analysis of water sources and a structured interview questionnaire.

Results

There were a total of 1430 reported TF cases. The outbreak’s epidemic curve shows earliest and highest peak attack rates (AR) in three military camps located in Kikwit (Ebeya 3.2%; Ngubu 3.0%; and Nsinga 2.2%) compared to an average peak AR of 0.6% in other affected areas. A total 320 cases from the military camps and the high burden health areas were interviewed. Typhoid cases in the military camps shared a latrine with more than one family (P<0.02). All tap water sources in both the military camps and general population were found to be highly contaminated with faecal coliforms.

Conclusion

The role of military camps in Kikwit as early hotspots of TF transmission was likely associated with lower sanitary and hygiene conditions. The proximity of camps to the general population might have been responsible for disseminating TF to the general population. Mapping of cases during an outbreak could be crucial to identify hot spots for transmission and institute corrective measures.

Massive Lower Gastrointestinal Bleed caused by Typhoid Ulcer: Conservative Management

Typhoid fever is caused by gram-negative organism Salmonella typhi. The usual presentation is high-grade fever, but complications like gastrointestinal (GI) hemorrhage and perforation are also seen frequently. With the advent of antibiotics, these complications are rarely seen now. We present a case of a young female who was admitted with a diagnosis of typhoid fever presented with a massive GI bleed from ulcers in the terminal ileum and was managed conservatively without endotherapy and surgery.

How to cite this article: Goel A, Bansal R. Massive Lower Gastrointestinal Bleed caused by Typhoid Ulcer: Conservative Management. Euroasian J Hepato-Gastroenterol 2017;7(2):176-177.

Encephalitis in a traveller with typhoid fever: efficacy of corticosteroids

Typhoid fever is a bacterial infection caused by Salmonella typhi or S. paratyphi, recognized as a classical cause of fever in returning travellers. However, neuropsychiatric presentations are rarely reported in travellers diagnosed in western countries, whereas they are more commonly described in patients treated in endemic areas. We describe such a case and discuss the pathophysiologic mechanisms of this complication.

An evaluation of purified Salmonella Typhi protein antigens for the serological diagnosis of acute typhoid fever

Objectives

The diagnosis of typhoid fever is a challenge. Aiming to develop a typhoid diagnostic we measured antibody responses against Salmonella Typhi (S. Typhi) protein antigens and the Vi polysaccharide in a cohort of Bangladeshi febrile patients.

Methods

IgM against 12 purified antigens and the Vi polysaccharide was measured by ELISA in plasma from patients with confirmed typhoid fever (n = 32), other confirmed infections (n = 17), and healthy controls (n = 40). ELISAs with the most specific antigens were performed on plasma from 243 patients with undiagnosed febrile disease.

Results

IgM against the S. Typhi protein antigens correlated with each other (rho > 0.8), but not against Vi (rho < 0.6). Typhoid patients exhibited higher IgM against 11/12 protein antigens and Vi than healthy controls and those with other infections. Vi, PilL, and CdtB exhibited the greatest sensitivity and specificity. Specificity and sensitivity was improved when Vi was combined with a protein antigen, generating sensitivities and specificities of 0.80 and >0.85, respectively. Applying a dynamic cut-off to patients with undiagnosed febrile disease suggested that 34–58% had an IgM response indicative of typhoid.

Conclusions

We evaluated the diagnostic potential of several S. Typhi antigens; our assays give good sensitivity and specificity, but require further assessment in differing patient populations.

Typhoid intestinal perforation in developing countries: Still unavoidable deaths?

Typhoid fever is a public health challenge mostly concentrated in impoverished, overcrowded areas of the developing world, with lack of safe drinking and sanitation. The most serious complication is typhoid intestinal perforation (TIP), observed in 0.8% to 39%, with a striking rate difference between high-income and low-middle-income countries. Although the mortality rate consequent to TIP in resource-poor countries is improved in the last decades, it is still fluctuating from 5% to 80%, due to surgical- and not surgical-related constraints. Huge economic costs and long timelines are required to provide a short- to middle-term solution to the lack of safe water and sanitation. Inherent limitations of the currently available diagnostic tools may lead to under-evaluation as well as over-evaluation of the disease, with consequent delayed treatment or inappropriate, excessive antibiotic use, hence increasing the likelihood of bacterial resistance. There is a need for immunization programs in populations at greatest risk, especially in sub-Saharan Africa. Uniform surgical strategies and guidelines, on the basis of sound or prospective surgical studies and adapted to the local realities, are still lacking. Major drawbacks of the surgical treatment are the frequent delays to surgery, either for late diagnosis or for difficult transports, and the unavailable appropriate intensive care units in most peripheral facilities. As a consequence, poor patient’s conditions at presentation, severe peritoneal contamination and unsuitable postoperative care are the foremost determinant of surgical morbidity and mortality.

Enteric Fever

Enteric fever is an important public-health problem in India. The clinical presentation of typhoid fever is very variable, ranging from fever with little other morbidities to marked toxemia and associated multisystem complications. Fever is present in majority of patients (>90 %) irrespective of their age group. Mortality is higher in younger children. Blood culture remains gold standard for diagnosis. Widal test has low sensitivity and specificity but may be used in second week to support the diagnosis. Emerging resistance to several antibiotics should be kept in mind when selecting antibiotics or revising the treatment. The key preventive strategies are safe water, safe food, personal hygiene, and appropriate sanitation. Vaccination is an additional effective tool for prevention.

Utility of Ty21a vaccine (Vivotif®)

Cases of diarrhoeal disease number from 1.7 to 5 billion per year worldwide. One of the main causes of diarrhoeal disease is typhoid fever, which is a potentially life-threatening multi-systemic illness. According to the most recent estimates, a total of 26.9 million typhoid fever episodes occurred in 2010. The geographical distribution of the disease differs widely; in developed countries, the incidence rate per 100,000 per year varies from < 0.1 to 0.3, and the disease mainly affects people who travel to endemic areas located in low- and middle-income countries. Low- and middle-income countries are mainly affected owing to the lack of clean water and proper sanitation. In the fight against this plague, prevention is fundamental, and vaccination against typhoid is an effective measure. Vivotif^® is an oral live attenuated vaccine which contains a mutated strain of Salmonella (Ty21a) and reproduces the natural infection. The vaccine was first licensed in Europe in 1983 and in the US in 1989, and over the years it has proved efficacious and safe. It is indicated for adults and children from 5 years of age upwards. Specifically, in the most developed countries, vaccination is suggested for highrisk population groups and particularly for international travellers to destinations where the risk of contracting typhoid fever is high. It must also be borne in mind that international travel is increasing. Indeed, international tourist arrivals totalled 1,184 million in 2015 and, on the basis of current trends, international travel is expected to grow by 3-4% in 2017. Vivotif^® appears to be a powerful means of disease prevention, the importance of which is highlighted by the spread of antibiotic-resistant strains of Salmonella typhy (S. typhi).

Blood culture-PCR to optimise typhoid fever diagnosis after controlled human infection identifies frequent asymptomatic cases and evidence of primary bacteraemia

Background

Improved diagnostics for typhoid are needed; a typhoid controlled human infection model may accelerate their development and translation. Here, we evaluated a blood culture-PCR assay for detecting infection after controlled human infection with S. Typhi and compared test performance with optimally performed blood cultures.

Methodology/Principal findings

Culture-PCR amplification of blood samples was performed alongside daily blood culture in 41 participants undergoing typhoid challenge. Study endpoints for typhoid diagnosis (TD) were fever and/or bacteraemia. Overall, 24/41 (59%) participants reached TD, of whom 21/24 (86%) had ≥1 positive blood culture (53/674, 7.9% of all cultures) or 18/24 (75%) had ≥1 positive culture-PCR assay result (57/684, 8.3%). A further five non-bacteraemic participants produced culture-PCR amplicons indicating infection; overall sensitivity/specificity of the assay compared to the study endpoints were 70%/65%. We found no significant difference between blood culture and culture-PCR methods in ability to identify cases (12 mismatching pairs, p = 0.77, binomial test). Clinical and stool culture metadata demonstrated that additional culture-PCR amplification positive individuals likely represented true cases missed by blood culture, suggesting the overall attack rate may be 30/41 (73%) rather than 24/41 (59%). Several participants had positive culture-PCR results soon after ingesting challenge providing new evidence for occurrence of an early primary bacteraemia.

Conclusions/Significance

Overall the culture-PCR assay performed well, identifying extra typhoid cases compared with routine blood culture alone. Despite limitations to widespread field-use, the benefits of increased diagnostic yield, reduced blood volume and faster turn-around-time, suggest that this assay could enhance laboratory typhoid diagnostics in research applications and high-incidence settings.

•

Culture in ox-bile/tryptone soy broth selectively enriches for bile-tolerant Salmonella Typhi while lysing human cells.

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PCR sensitivity for detecting typhoid in clinical blood is limited by very low level bacteraemia during clinical illness.

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PCR amplification of S. Typhi fliC-d in pre-cultured blood can accurately identify typhoid infection in challenge study participants.

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Daily culture-PCR of blood collected from challenge study participants suggests primary bacteraemia occurs 12–36 h after S. Typhi ingestion.

•

Additional use of culture-PCR demonstrates the true attack rate after typhoid challenge is markedly higher (75%) than previously assumed (60%).

A large and persistent outbreak of typhoid fever caused by consuming contaminated water and street-vended beverages: Kampala, Uganda, January - June 2015

Background

On 6 February 2015, Kampala city authorities alerted the Ugandan Ministry of Health of a “strange disease” that killed one person and sickened dozens. We conducted an epidemiologic investigation to identify the nature of the disease, mode of transmission, and risk factors to inform timely and effective control measures.

Methods

We defined a suspected case as onset of fever (≥37.5 °C) for more than 3 days with abdominal pain, headache, negative malaria test or failed anti-malaria treatment, and at least 2 of the following: diarrhea, nausea or vomiting, constipation, fatigue. A probable case was defined as a suspected case with a positive TUBEX® TF test. A confirmed case had blood culture yielding Salmonella Typhi. We conducted a case-control study to compare exposures of 33 suspected case-patients and 78 controls, and tested water and juice samples.

Results

From 17 February–12 June, we identified 10,230 suspected, 1038 probable, and 51 confirmed cases. Approximately 22.58% (7/31) of case-patients and 2.56% (2/78) of controls drank water sold in small plastic bags (OR_M-H = 8.90; 95%CI = 1.60–49.00); 54.54% (18/33) of case-patients and 19.23% (15/78) of controls consumed locally-made drinks (OR_M-H = 4.60; 95%CI: 1.90–11.00). All isolates were susceptible to ciprofloxacin and ceftriaxone. Water and juice samples exhibited evidence of fecal contamination.

Conclusion

Contaminated water and street-vended beverages were likely vehicles of this outbreak. At our recommendation authorities closed unsafe water sources and supplied safe water to affected areas.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-4002-0) contains supplementary material, which is available to authorized users.

Low and declining attack rates of imported typhoid fever in the Netherlands 1997-2014, in spite of a restricted vaccination policy

Background

Typhoid fever mainly occurs in (sub) tropical regions where sanitary conditions remain poor. In other regions it occurs mainly among returning travelers or their direct contacts. The aim of this study was to evaluate the current Dutch guidelines for typhoid vaccination.

Method

Crude annual attack rates (AR) per 100,000 Dutch travelers were calculated during the period 1997 to 2014 by dividing the number of typhoid fever cases by the estimated total number of travelers to a specific country or region. Regions of exposure and possible risk factors were evaluated.

Results

During the study period 607 cases of typhoid fever were reported. Most cases were imported from Asia (60%). Almost half of the cases were ethnically related to typhoid risk regions and 37% were cases visiting friends and relatives. The overall ARs for travelers to all regions declined significantly. Countries with the highest ARs were India (29 per 100,000), Indonesia (8 per 100,000), and Morocco (10 per 100,000). There was a significant decline in ARs among travelers to popular travel destinations such as Morocco, Turkey, and Indonesia. ARs among travelers to intermediate-risk areas according to the Dutch guidelines such as Latin America or Sub-Saharan Africa remained very low, despite the restricted vaccination policy for these areas compared to many other guidelines.

Conclusion

The overall AR of typhoid fever among travelers returning to the Netherlands is very low and has declined in the past 20 years. The Dutch vaccination policy not to vaccinate short-term travelers to Latin-America, Sub-Saharan Africa, Thailand and Malaysia seems to be justified, because the ARs for these destinations remain very low. These results suggest that further restriction of the Dutch vaccination policy is justified.

Severe thrombocytopenia in a child with typhoid fever: a case report

Background

Although thrombocytopenia is common in typhoid fever, its course, response to treatment, and need for specific therapies such as platelet transfusion are not well characterized.

Case presentation

We report a case of typhoid fever in a 4-year-old Asian male returned traveler, admitted with prolonged fever and found to have severe thrombocytopenia (platelets 16 × 10⁹/L). Despite appropriate antibiotic therapy, his platelet recovery was slow, but did not lead to complications and he did not require platelet transfusion.

Conclusions

There is no consensus in the medical literature guiding the optimal management of severe thrombocytopenia in typhoid fever, but it may improve with conservative management, as in our case. The epidemiology and management of this condition merits further research to guide clinical practice.

Enteric fever in Barcelona: Changing patterns of importation and antibiotic resistance

BACKGROUND

Enteric fever's incidence is decreasing among residents of high-income countries, although it's rising in travelers coming from low-resource endemic settings. The study's aim is to describe epidemiological, clinical and laboratory features of patients with enteric fever.

METHODS

Retrospective descriptive study of enteric fever cases diagnosed at a Tropical Medicine Unit in Barcelona, 1993-2012.

RESULTS

Out of 40 patients, 31(77,5%) were returning travelers, and 70% of them had been in Southern Asia. In the rest of patients without an antecedent of a recent travel, the infection occurred mainly before year 2000. The more frequently reported symptoms were fever and diarrhea, lacking significant differences between S. typhi and S. paratyphi infections. Quinolones were used as empiric treatment in 47.2% of patients, 36.1% received 3rd generation cephalosporins, 2.78% azithromycin and 13.89% other combinations. Resistance to quinolones in the S. paratyphi group (66.7%) was significantly higher compared with the S. typhi group (20%) (p:0.02). 22.5% of patients had treatment failure and 23.6% patients presented complications, none of them had been previously vaccinated.

CONCLUSIONS

The diagnosis of enteric fever was more frequent among travelers coming from Southern-East Asia. Quinolone resistance is widely spread, particularly in S. paratyphi serotypes and should not be considered as first choice treatment anymore.

Diagnosis of imported Ugandan typhoid fever based on local outbreak information: A case report

Re-emerging multidrug-resistant typhoid fever is becoming a worldwide threat, especially in East Africa. At the beginning of 2015, an outbreak of typhoid fever started in the capital city of Uganda, and 1940 suspected cases were reported by 5 March 2015. In this report, we describe a case of typhoid fever caused by a MDR strain with HIV infection and hemoglobin S-syndrome thalassemia in an Ugandan from Kampala City. It is essential to consider MDR strains of Salmonella enterica serovar Typhi infections, including fluoroquinolone-resistant strains, in patients from Africa and Southeast Asia.

Mechanisms of Salmonella Typhi Host Restriction

Salmonella enterica serovar Typhi (S. Typhi) is the cause of typhoid fever, a life-threatening bacterial infection that is very common in the developing world. Recent spread of antimicrobial resistant isolates of S. Typhi makes typhoid fever, a global public health risk. Despite being a common disease, still very little is known about the molecular mechanisms underlying typhoid fever and S. Typhi pathogenesis. In contrast to other Salmonellae, S. Typhi can only infect humans. The molecular bases of this human restriction are mostly unknown. Recent studies identified a novel pathway that contributes to S. Typhi human restriction and is required for killing S. Typhi in macrophages of nonsusceptible species. The small Rab GTPase Rab32 and its guanine nucleotide exchange factor BLOC-3 are the critical components of this pathway. These proteins were already well known as important regulators of intracellular membrane transport. In particular, they are central for the transport of enzymes that synthetize melanin in pigment cells. The recent findings that Rab32 and BLOC-3 are required for S. Typhi host restriction point out to a novel mechanism restricting the growth of bacterial pathogen, dependent on the transport of still unknown molecule(s) to the S. Typhi vacuole. The identification of this novel antimicrobial pathway constitutes a critical starting point to study molecular mechanisms killing bacterial pathogens and possibly identify novel antimicrobial molecules.

Using nursing history to inform decision-making: Infectious diseases at the turn of the 20th century

BACKGROUND

This historical paper examines the impact of infectious diseases on the urban poor of Chicago and New York a century ago, before most vaccines were developed.

PURPOSE

Working on the front lines of health promotion and health care, nurses and other providers are charged with informing the public about offered vaccines. The intent of this paper is to supplement providers' knowledge about vaccination with an appreciation of the devastation these diseases once caused.

METHOD

Historical methodology guided this study in which archival and oral sources were used.

DISCUSSION

The continued outbreaks of smallpox at the turn of the twentieth century, when a vaccine was available, may be compared with the re-emergence of measles today. Additionally, this paper shows the devastation caused by other, non-preventable, infections of the period.

CONCLUSIONS

Awareness of the history related to the impact of infectious diseases, especially the role nurses played in decision-making related to care, is critical for today's health care providers.

Typhoid transmission: a historical perspective on mathematical model development

Mathematical models of typhoid transmission were first developed nearly half a century ago. To facilitate a better understanding of the historical development of this field, we reviewed mathematical models of typhoid and summarized their structures and limitations. Eleven models, published in 1971 to 2014, were reviewed. While models of typhoid vaccination are well developed, we highlight the need to better incorporate water, sanitation and hygiene interventions into models of typhoid and other foodborne and waterborne diseases. Mathematical modeling is a powerful tool to test and compare different intervention strategies which is important in the world of limited resources. By working collaboratively, epidemiologists and mathematicians should build better mathematical models of typhoid transmission, including pharmaceutical and non-pharmaceutical interventions, which will be useful in epidemiological and public health practice.

Enteric fever in a British soldier from Sierra Leone

Enteric fever (typhoid and paratyphoid) remains a threat to British troops overseas and causes significant morbidity and mortality. We report the case of a soldier who developed typhoid despite appropriate vaccination and field hygiene measures, which began 23 days after returning from a deployment in Sierra Leone. The incubation period was longer than average, symptoms started 2 days after stopping doxycycline for malaria chemoprophylaxis and initial blood cultures were negative. The Salmonella enterica serovar Typhi eventually isolated was resistant to amoxicillin, co-amoxiclav, co-trimoxazole and nalidixic acid and had reduced susceptibility to ciprofloxacin. He was successfully treated with ceftriaxone followed by azithromycin, but 1 month later he remained fatigued and unable to work. The clinical and laboratory features of enteric fever are non-specific and the diagnosis should be considered in troops returning from an endemic area with a febrile illness. Multiple blood cultures and referral to a specialist unit may be required.

Typhoid Intestinal Perforations: Has the Clinical Importance Decreased in Eastern Anatolia for 36 Years?

OBJECTIVE

Typhoid fever (TF) is an important health problem in developing countries, and typhoid intestinal perforation (TIP) is a serious complication of TF. The present report aims to determine the clinical importance of TIPs for the last 36 years in our region, eastern Anatolia.

MATERIALS AND METHODS

The clinical records of 84 surgically treated cases with TIPs were reviewed retrospectively.

RESULTS

When the last 36-year period was sectioned by 6-year periods, the distribution of TIPs was found as 39 (46.4% of total), 31 (36.9%), 7 (8.3%), 4 (4.8%), 2 (2.4%) and 1 (1.2%), respectively. The mean age of the patients was 37.1 years (range: 7-68 years), and 66 patients (78.6%) were male. As a surgical procedure, 34 patients (40.5%) had primary repair, 9 (10.7%) had wedge resection with primary repair, 9 (10.7%) had resection with primary anastomosis, 28 (33.3%) had resection with ileostomy, and 4 (4.8%) had exteriorization. Complications were seen in 71 patients (84.5%), while the mortality rate was 10.7% (9 patients).

CONCLUSION

Although eastern Anatolia is an endemic region for TF, a certain decrease in the incidence of TIPs was found for the last 36 years. Keeping in mind the TIP, patients with TF may improve the prognosis of this serious disease.

Typhoid fever vaccination strategies

Typhoid vaccination is an important component of typhoid fever prevention and control, and is recommended for public health programmatic use in both endemic and outbreak settings. We reviewed experiences with various vaccination strategies using the currently available typhoid vaccines (injectable Vi polysaccharide vaccine [ViPS], oral Ty21a vaccine, and injectable typhoid conjugate vaccine [TCV]). We assessed the rationale, acceptability, effectiveness, impact and implementation lessons of these strategies to inform effective typhoid vaccination strategies for the future. Vaccination strategies were categorized by vaccine disease control strategy (preemptive use for endemic disease or to prevent an outbreak, and reactive use for outbreak control) and vaccine delivery strategy (community-based routine, community-based campaign and school-based). Almost all public health typhoid vaccination programs used ViPS vaccine and have been in countries of Asia, with one example in the Pacific and one experience using the Ty21a vaccine in South America. All vaccination strategies were found to be acceptable, feasible and effective in the settings evaluated; evidence of impact, where available, was strongest in endemic settings and in the short- to medium-term. Vaccination was cost-effective in high-incidence but not low-incidence settings. Experience in disaster and outbreak settings remains limited. TCVs have recently become available and none are WHO-prequalified yet; no program experience with TCVs was found in published literature. Despite the demonstrated success of several typhoid vaccination strategies, typhoid vaccines remain underused. Implementation lessons should be applied to design optimal vaccination strategies using TCVs which have several anticipated advantages, such as potential for use in infant immunization programs and longer duration of protection, over the ViPS and Ty21a vaccines for typhoid prevention and control.