Overview of the impact of Typhoid and Paratyphoid fever. 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).

Regional Transmission of Salmonella Paratyphi A, China, 1998-2012.

To explore transmission patterns and genetic relationships of Salmonella enterica serovar Paratyphi A in China, we conducted a genome-wide single-nucleotide polymorphism analysis on the strains in the 4 provinces in which incidence was highest during 1998-2012. Markedly phylogeographic clustering suggested regional virus circulation after introduction from areas in southeastern China.

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.

Molecular characteristics of Salmonella enterica Paratyphi A in Yunnan Province, southwest China.

Previously, the prevalence of Salmonella enterica Paratyphi A in Yunnan was high; and recently Yunnan was the predominant endemic province in China. To identify the molecular epidemiology, antibiotic resistance profile and genotypic diversity of the S. Paratyphi A isolates from 1995 to 2013 in Yunnan, we performed the study. Antibiotic susceptibility tests, pulse-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to identify the characteristics of the bacterial isolates. The results showed from 1995 to 2013, 366 S. Paratyphi A were isolated: 295 isolates (80.6%) from Yuxi and 68 isolates (18.58%) from Honghe. All of the strains were resistant to nalidixic acid, and some were resistant to ampicillin and trimethoprim/sulfamethoxazole in different years. All the isolates were sensitive to cefotaxime and ciprofloxacin. Identical PFGE with two enzyme digestion patterns were found for 339 isolates. Some environmental isolates in different years were homologous with the strains isolated from food and patients. MLST showed 349 strains were ST85, only 17 isolates were ST129. S. Paratyphi A isolates from Yunnan showed a high similarity, and we found the pathogen isolated from patients, the environment and food had the close epidemiological relationship, forming a transmission circulation. These findings have important implications for paratyphoid-control strategies.

[Demarcation of infection with Salmonella typhi and S. paratyphi against Salmonella enteritidis in children]. / Abgrenzung von Infektionen mit Salmonella typhi und S. paratyphi gegenüber Infektionen mit S. enteritidis bei Kindern.

BACKGROUND: Typhoid and paratyphoid infections (STP) are an important differential diagnosis for Salmonella enteritidis infections (NTS). The aim of this study is to carve out clinical differences between both infections. PATIENTS/METHODS: We retrospectively reviewed all patients admitted to our hospital between 2007 and 2011 with a diagnosis of STP infection. History, clinical course and laboratory findings were compared with age-matched patients suffering from NTS. RESULTS/DISCUSSION: All patients with an STP-infection showed had a positive travel history (as compared to 11.1% in the NTS group, p<0.01). Salmonella were mostly isolated from blood cultures (n=7/9) in the STP group as compared to 1/16 in the NTS group, where S. enteridis was mainly isolated from faecal cultures (p<0,01). The duration and height of fever as well as the time of hospitalization were significantly longer with STP infections than with NTS infections. Eosinopenia was observed both in STP-(100%) and NTS-infections (77.8%). CONCLUSION: A positive travel history is crucial to the identification of a STP infection, as well as an eosinopenia.

Low compliance with national guidelines for preventing transmission of group 1 nationally notifiable infectious diseases in Korea.

PURPOSE: This study was performed to evaluate the compliance with, and adequacy of, the Korean national guidelines which had been recommended until 2011 for isolation of patients with group 1 nationally notifiable infectious diseases (NNIDs), namely cholera, typhoid fever, paratyphoid fever, shigellosis, and enterohemorrhagic Escherichia coli (EHEC) infection. MATERIALS AND METHODS: We evaluated the clinical and microbiological characteristics of confirmed cases of group 1 NNIDs and compliance with the guidelines in 20 Korean hospitals nationwide in 2000-2010. We also compared the Korean guidelines with international guidelines. RESULTS: Among 528 confirmed cases (8 cases of cholera, 232 of typhoid fever, 81 of paratyphoid fever, 175 of shigellosis, and 32 EHEC infections), strict compliance with the Korean guideline was achieved in only 2.6% to 50.0%, depending on the disease. While the Korean guidelines recommend isolation of all patients with group 1 NNIDs, international guidelines recommend selective patient isolation and screening for fecal shedding, depending on the type of disease and patient status. CONCLUSION: Compliance with the previous national guidelines for group 1 NNIDs in Korea was generally very low. Further studies are needed to evaluate whether compliance was improved after implementation of the new guideline in 2012.

Unusual increase in reported cases of paratyphoid A fever among travellers returning from Cambodia, January to September 2013.

From January to September 2013, a marked increase in notifications of Salmonella Paratyphi A infections among travellers returning from Cambodia occurred in France. An investigation revealed 35 cases without a common source: 21 in France, five in Germany, three in the Netherlands, one in Norway, one in the United Kingdom, four in New-Zealand. Data suggest an ongoing event that should trigger further investigation. Travellers to Cambodia should observe preventive measures including good personal hygiene and food handling practices.

Spatiotemporal transmission and determinants of typhoid and paratyphoid fever in Hongta District, Yunnan Province, China.

BACKGROUND: Typhoid and paratyphoid fever are endemic in Hongta District and their prevalence, at 113 per 100,000 individuals, remains the highest in China. However, the exact sources of the disease and its main epidemiological characteristics have not yet been clearly identified. METHODS AND FINDINGS: Numbers of typhoid and paratyphoid cases per day during the period 2006 to 2010 were obtained from the Chinese Center of Disease Control (CDC). A number of suspected disease determinants (or their proxies), were considered for use in spatiotemporal analysis: these included locations of discharge canals and food markets, as well as socio-economic and environmental factors. Results showed that disease prevalence was spatially clustered with clusters decreasing with increasing distance from markets and discharge canals. More than half of the spatial variance could be explained by a combination of economic conditions and availability of health facilities. Temporal prevalence fluctuations were positively associated with the monthly precipitation series. Polluted hospital and residential wastewater was being discharged into rainwater canals. Salmonella bacteria were found in canal water, on farmland and on vegetables sold in markets. CONCLUSION: DISEASE TRANSMISSION IN HONGTA DISTRICT IS DRIVEN PRINCIPALLY BY TWO SPATIOTEMPORALLY COUPLED CYCLES: one involving seasonal variations and the other the distribution of polluted farmland (where vegetables are grown and sold in markets). Disease transmission was exacerbated by the fact that rainwater canals were being used for disposal of polluted waste from hospitals and residential areas. Social factors and their interactions also played a significant role in disease transmission.

Public health management of Salmonella Typhi/Paratyphi case and contact screening: lessons from North London.

OBJECTIVES: To evaluate the public health management Salmonella enterica serovar Typhi (typhoid) and Salmonella enterica serovar Paratyphi (paratyphoid) cases and their contacts to assess the outcome of screening. STUDY DESIGN: Retrospective case note review. METHODS: 329 cases and 1153 contacts from North London over a four year period were reviewed. Structured questionnaires were developed to capture travel history, relationship between case/contact and the number, timing and documented results of faecal specimens. Evaluation of compliance with the clearance/screening schedule was examined and the positive yield of faecal samples for cases and contacts was calculated. RESULTS: 1% (3/329) of cases had a positive clearance sample; all were identified on their first faecal specimen. Of the 645 contacts who were screened, only 10 (1.5%), all of whom had travelled with the index case, were positive. Person-to-person transmission was only identified for two UK acquired cases, where possible carrier sources were identified outside the screening schedule. CONCLUSION: The lack of evidence of secondary transmission from acute cases, coupled with the low positive yield from clearance samples support the revision of the national guidance for the public health management of cases of enteric fever and their contacts.

Typhoid and paratyphoid fever in Western Sydney Local Health District, NSW, January-June 2011.

We undertook a study of enteric fever, caused by Salmonella enterica enterica subtypes Typhi and Paratyphi A, presenting in residents of the Western Sydney Local Health District for the period January-June 2011. Twelve cases of S. Typhi and eight of S. Paratyphi A were notified. Patients were predominantly young adults (median age 26 years, 70% female) who had been visiting friends and relatives in India, Samoa, Bangladesh or Sri Lanka. No cases were associated with travel for less than 3 weeks; 17 (85%) required hospitalisation. None received pre-travel vaccination; reasons cited for this included pregnancy, expense, being too busy, or considering the disease too mild to warrant vaccination. Three S. Typhi isolates acquired at large social gatherings in Samoa had the same phage [corrected] type and susceptibility profiles; these results were communicated to Samoan public health personnel. There are opportunities to strengthen enteric fever prevention, including pre-travel health advice and S. Typhi vaccination for people visiting endemic areas for 3 or more weeks, especially those in the vulnerable 'visiting friends and relative' category.

Salmonella Paratyphi B var Java infections associated with exposure to turtles in Bizkaia, Spain, September 2010 to October 2011.

Between September 2010 and October 2011, the Unit of Epidemiology in the Department of Public Health in Bizkaia, Spain identified eight cases of Salmonella Paratyphi B var Java infection and three cases of infection with its possible monophasic variant 4,5,12:b:- dT+. Six cases reported contact with turtles and S. Java was isolated from three of these turtles' habitats. The isolates from the patients and their respective turtles were indistinguishable by pulsed-field gel electrophoresis (PFGE). Although other reptiles can also carry Salmonella, turtles pose a special risk, as they are commonly kept as pets for children. This emphasizes the need to give recommendations regarding ownership and handling of aquatic turtles and other reptiles. As parents are often not aware of the risk of infection associated with the presence of turtles in the household, it would be appropriate to inform potential buyers at points of sale about the risk of infection and measures they can take to minimise this risk.

[Salmonella's transmission from turtle to child: public health nursing experience about a new case]. / Transmisión de Salmonella entre tortugas y niños: experiencia de la enfermería de salud pública a propósito de un caso.

Salmonellosis is usually related to food poisoning however other possible causes such as reptile exposure are often unrecognised. The aim of this study is to describe a case of salmonella infection related to pet exposure. After a salmonella infection in an eleven month old baby was reported to our public health agency, an epidemiological investigation took place. Despite all family members had had clinical symptoms suggesting salmonella infection none of the microbiological analysis was positive. At the infant's home they had an exotic pet: a turtle. We found out that Salmonella was present in a sample of water of its aquarium. Both profiles of S. parathyphi B (from the infant and from the aquaria samples) were identical. Exotic pets are not often recognized as Salmonella infection carriers and vehicles in Europe. As described in this study, an inaccurate hygiene after touching turtles or its habitat can lead to spread salmonella infection in humans. When investigating Salmonella infection exposure to exotic pets has to be addressed. People that have or wish to have a turtle or any other reptile should be informed about its risks. Nursing role is most important in the surveillance and study of such cases.

[Notable imported infectious diseases].

Japanese doctors are somewhat unfamiliar with imported infectious diseases, however, the following imported infectious diseases are notable: cholera, which is currently endemic in Haiti and which there is a possibility of it being imported to Japan from endemic areas; typhoid fever and paratyphoid fever, whose causative organisms showing low sensitivity to fluoroquinolones have become predominant; rabies, which exhibits a high mortality; avian influenza H5N1, which has the possibility of changing into a new type of human influenza; chikungunya fever, in which the number of Japanese patients is increasing; and cyclosporiasis, which led to a number of food poisonings in the USA and Canada, and as a growing number of Japanese travel abroad, the number of infected Japanese patients returning from endemic areas will increase. It is thus important to identify the presence of these diseases on diagnosis.

Neonatal sepsis due to Salmonella Typhi and Paratyphi A.

Sepsis due to Salmonella enterica serovar Typhi and Paratyphi A is rare in neonates. Though described as a mild and unrecognized illness in infants, life-threatening complications and even deaths have been reported. We present five cases of neonatal septicaemia due to S. Typhi and S. Paratyphi A. The cases were presented because of their interesting clinical presentations and possible modes of transmission. Salmonella infections should be considered in the differential diagnosis of sepsis neonatorum, especially in endemic areas.

Darkling beetles (Alphitobius diaperinus) and their larvae as potential vectors for the transfer of Campylobacter jejuni and Salmonella enterica serovar paratyphi B variant Java between successive broiler flocks.

Broiler flocks often become infected with Campylobacter and Salmonella, and the exact contamination routes are still not fully understood. Insects like darkling beetles and their larvae may play a role in transfer of the pathogens between consecutive cycles. In this study, several groups of beetles and their larvae were artificially contaminated with a mixture of Salmonella enterica serovar Paratyphi B Variant Java and three C. jejuni strains and kept for different time intervals before they were fed to individually housed chicks. Most inoculated insects were positive for Salmonella and Campylobacter just before they were fed to the chicks. However, Campylobacter could not be isolated from insects that were kept for 1 week before they were used to mimic an empty week between rearing cycles. All broilers fed insects that were inoculated with pathogens on the day of feeding showed colonization with Campylobacter and Salmonella at levels of 50 to 100%. Transfer of both pathogens by groups of insects that were kept for 1 week before feeding to the chicks was also observed, but at lower levels. Naturally contaminated insects that were collected at a commercial broiler farm colonized broilers at low levels as well. In conclusion, the fact that Salmonella and Campylobacter can be transmitted via beetles and their larvae to flocks in successive rearing cycles indicates that there should be intensive control programs for exclusion of these insects from broiler houses.

Comparisons of predictors for typhoid and paratyphoid fever in Kolkata, India.

BACKGROUND: Exposure of the individual to contaminated food or water correlates closely with the risk for enteric fever. Since public health interventions such as water improvement or vaccination campaigns are implemented for groups of individuals we were interested whether risk factors not only for the individual but for households, neighbourhoods and larger areas can be recognised? METHODS: We conducted a large enteric fever surveillance study and analyzed factors which correlate with enteric fever on an individual level and factors associated with high and low risk areas with enteric fever incidence. Individual level data were linked to a population based geographic information systems. Individual and household level variables were fitted in Generalized Estimating Equations (GEE) with the logit link function to take into account the likelihood that household factors correlated within household members. RESULTS: Over a 12-month period 80 typhoid fever cases and 47 paratyphoid fever cases were detected among 56,946 residents in two bustees (slums) of Kolkata, India. The incidence of paratyphoid fever was lower (0.8/1000/year), and the mean age of paratyphoid patients was older (17.1 years) than for typhoid fever (incidence 1.4/1000/year, mean age 14.7 years). Residents in areas with a high risk for typhoid fever had lower literacy rates and economic status, bigger household size, and resided closer to waterbodies and study treatment centers than residents in low risk areas. CONCLUSION: There was a close correlation between the characteristics detected based on individual cases and characteristics associated with high incidence areas. Because the comparison of risk factors of populations living in high versus low risk areas is statistically very powerful this methodology holds promise to detect risk factors associated with diseases using geographic information systems.

Vertical transmission of Salmonella paratyphi A.

Neonatal enteric fever is a rare but life-threatening illness. Patients may present with varying severity, Salmonella enterica serotype Typhi causing more severe illness than Salmonella enterica serotype Paratyphi A. Salmonella enterica serotype Paratyphi A is considered to cause milder infection with fewer complications. We report a rare case of vertical transmission of Salmonella enterica serotype Paratyphi A with severe complications and high mortality. Even though there are case reports of vertical transmission of Salmonella enterica serotype Typhi, to our knowledge, this is the first case report of vertical transmission of Salmonella enterica serotype ParatyphiA. The role of blood culture in accurate diagnosis and treatment is also discussed.