Objective: To analyze the incidence trend and epidemiological characteristics of typhoid fever and paratyphoid fever in China from 2004 to 2020, understand the high-incidence population and hotspot areas, and provide evidences to develop more targeted prevention and control measures. Methods: The descriptive epidemiological method and spatial analysis method were applied to analyze the epidemiological characteristics of typhoid fever and paratyphoid fever in China during this period by using the surveillance data collected from the National Notifiable Infectious Disease Reporting System of Chinese Center for Disease Control and Prevention. Results: A total of 202 991 cases of typhoid fever were reported in China from 2004 to 2020. More cases occurred in men than in women (sex ratio: 1.18∶1). Most cases were reported in adults aged 20-59 years (53.60%). The incidence rate of typhoid fever decreased from 2.54/100 000 in 2004 to 0.38/100 000 in 2020. The highest incidence rate was reported in young children aged <3 years after 2011, ranging from 1.13/100 000 to 2.78/100 000, and during this period the proportion of cases in this age group increased from 3.48% to 15.59%. The proportion of the cases in the elderly aged ≥60 years increased from 6.46% in 2004 to 19.34% in 2020. The hotspot areas existed in Yunnan, Guizhou, Guangxi and Sichuan Provinces and expanded to Guangdong, Hunan, Jiangxi, and Fujian Provinces. A total of 86 226 paratyphoid fever cases were reported from 2004 to 2020, the male to female ratio of the cases was 1.21∶1. Most cases were reported in adults aged 20-59 years (59.80%). The incidence rate of paratyphoid fever decreased from 1.26/100 000 in 2004 to 0.12/100 000 in 2020. The highest incidence rate of paratyphoid fever was in young children aged <3 years after 2007, ranging from 0.57/100 000 to 1.19/100 000, and during this period the proportion of the cases in this age group increased from 1.48% to 30.92%. The proportion of the cases in the elderly aged ≥60 years increased from 4.52% in 2004 to 22.28% in 2020. The hotspot areas expanded to the east, including Guangdong, Hunan and Jiangxi Provinces, from Yunnan, Guizhou, Sichuan, and Guangxi Provinces. Conclusions: The results showed a low level of incidence of typhoid fever and paratyphoid fever in China with a trend of decreasing per year. The hotspots were mainly in the of Yunnan, Guizhou, Guangxi and Sichuan Provinces, with an expanding trend to eastern China. It is necessary to strengthen the typhoid fever and paratyphoid fever prevention and control in southwestern China, among young children aged <3 years and the elderly aged ≥60 years.
Adult ; Aged ; Child, Preschool ; Female ; Humans ; Male ; China/epidemiology* ; Paratyphoid Fever/epidemiology* ; Sex Ratio ; Typhoid Fever/epidemiology* ; Young Adult ; Middle Aged

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.
Child ; Child, Preschool ; China/epidemiology* ; Disease Outbreaks ; Drug Resistance, Bacterial/genetics* ; Electrophoresis, Gel, Pulsed-Field ; Epidemics ; Farmers ; Humans ; Incidence ; Infant ; Molecular Typing ; Paratyphoid Fever/microbiology* ; Population Surveillance ; Salmonella paratyphi A/isolation & purification* ; Salmonella typhi/isolation & purification* ; Typhoid Fever/microbiology*

INTRODUCTIONEnteric fever is a multisystemic infection which largely affects children. This study aimed to analyse the epidemiology, clinical presentation, treatment and outcome of paediatric enteric fever in Singapore.

MATERIALS AND METHODSA retrospective review of children diagnosed with enteric fever in a tertiary paediatric hospital in Singapore was conducted from January 2006 to January 2012. Patients with positive blood cultures for Salmonella typhi or paratyphi were identified from the microbiology laboratory information system. Data was extracted from their case records.

RESULTSOf 50 enteric fever cases, 86% were due to Salmonella typhi, with 16.3% being multidrug resistant (MDR) strains. Sixty-two percent of S. typhi isolates were of decreased ciprofloxacin susceptibility (DCS). Five cases were both MDR and DCS. The remaining 14% were Salmonella paratyphi A. There were only 3 indigenous cases. Ninety-four percent had travelled to typhoid-endemic countries, 70.2% to the Indian subcontinent and the rest to Indonesia and Malaysia. All patients infected with MDR strains had travelled to the Indian subcontinent. Anaemia was a significant finding in children with typhoid, as compared to paratyphoid fever (P = 0.04). Although all children were previously well, 14% suffered severe complications including shock, pericardial effusion and enterocolitis. None had typhoid vaccination prior to their travel to developing countries.

CONCLUSIONEnteric fever is largely an imported disease in Singapore and has contributed to significant morbidity in children. The use of typhoid vaccine, as well as education on food and water hygiene to children travelling to developing countries, needs to be emphasised.

Adolescent ; Anemia ; epidemiology ; Anti-Bacterial Agents ; therapeutic use ; Child ; Child, Preschool ; Drinking Water ; Drug Resistance, Multiple, Bacterial ; physiology ; Enterocolitis ; epidemiology ; Female ; Food Contamination ; Health Education ; Hospitals, Pediatric ; Humans ; India ; Indonesia ; Infant ; Malaysia ; Male ; Paratyphoid Fever ; drug therapy ; epidemiology ; microbiology ; Pericardial Effusion ; epidemiology ; Retrospective Studies ; Salmonella paratyphi A ; physiology ; Salmonella typhi ; physiology ; Shock ; epidemiology ; Singapore ; epidemiology ; Tertiary Care Centers ; Travel ; Typhoid Fever ; drug therapy ; epidemiology ; microbiology ; prevention & control ; Typhoid-Paratyphoid Vaccines ; therapeutic use

BACKGROUND: Travel-related risks for infectious diseases vary depending on travel patterns such as purpose, destination, and duration. In this study, we describe the patterns of travel and prescription of vaccines as well as malaria prophylaxis medication (MPM) at a travel clinic in South Korea to identify the gaps to fill for the optimization of pre-travel consultation. MATERIALS AND METHODS: A cohort of travel clinic visitors in 2011 was constructed and early one-third of the visitors of each month were reviewed. During the study period, 10,009 visited the travel clinic and a retrospective chart review was performed for 3,332 cases for analysis of travel patterns and prescriptions. RESULTS: People receiving yellow fever vaccine (YFV) (n = 2,933) were traveling more frequently for business and tourism and less frequently for providing non-medical service or research/education compared to the 399 people who did not receive the YFV. Overall, most people were traveling to Eastern Africa, South America, and Western Africa, while South-Eastern Asia was the most common destination for the non-YFV group. Besides YFV, the typhoid vaccine was the most commonly prescribed (54.2%), while hepatitis A presented the highest coverage (74.7%) considering the natural immunity, prior and current vaccination history. Additionally, 402 (82.5%) individuals received a prescription for MPM among the 487 individuals travelling to areas with high-risk of malaria infection. Age over 55 was independently associated with receiving MPM prescription, while purpose of providing service and travel duration over 10 days were associated with no MPM prescription, despite travelling to high-risk areas. CONCLUSION: Eastern Africa and South America were common travel destinations among the visitors to a travel clinic for YFV, and most of them were travelling for tourism and business. For the individuals who are traveling to areas with high-risk for malaria, more proactive approach might be required in case of younger age travelers, longer duration, and travel purpose of providing service to minimize the risk of malaria infection.
Africa, Eastern ; Africa, Western ; Antibiotic Prophylaxis ; Asia ; Cohort Studies ; Commerce ; Communicable Diseases ; Hepatitis A ; Immunity, Innate ; Korea* ; Malaria ; Prescriptions* ; Retrospective Studies ; South America ; Travel Medicine ; Typhoid-Paratyphoid Vaccines ; Vaccination* ; Vaccines ; Yellow Fever Vaccine ; Yellow Fever*

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.
Cholera ; Communicable Disease Control ; Communicable Diseases* ; Compliance* ; Dysentery, Bacillary ; Enterohemorrhagic Escherichia coli ; Guideline Adherence ; Humans ; Korea* ; Mass Screening ; Methods ; Paratyphoid Fever ; Patient Isolation ; Typhoid Fever

OBJECTIVEThis study was to evaluate the effects of prevention and control regarding programs on typhoid fever and paratyphoid fever, in Guizhou province, from 2007 to 2012, to provide evidence for the improvement of related programs.

METHODSData on typhoid fever and paratyphoid including information on epidemics, individual, cases, measures for prevention and control programs taken and relative government documents were collected and analyzed in Guizhou province, from 2007 to 2012. Information related to the average annual incidence, nature of outbreaks, time span before confirmed diagnosis was made, unit which carried the case report, proportion of laboratory confirmed diagnosed cases and case-management were compared between 2007-2009 and 2010-2012 descriptively while chi-square test with Excel and EpiInfo software were used for data analysis.

RESULTSIn the period of 2007-2009, a total of 5 978 typhoid fever and paratyphoid fever cases were reported in Guizhou province with the average yearly incidence as 5.29/100 000. In the period of 2010-2012, 2 765 cases were reported with the average yearly incidence as 2.57/100 000. When compared to the former, data from the latter period showed that the average yearly incidence had declined 51.31% in all the prefectures. There were still some outbreaks appeared but the total number of cases involved reduced 87.50%. The time span before the confirmation of diagnosis became shorter but the difference was not statistically significant (χ² = 0.08, P = 0.99). Number of cases reported by hospitals at county or above had 11.51% of increase while those cases reported at the township hospitals or below decreased for 61.47% . The proportion of laboratory diagnosed cases increased 23.63%. Rates of timeliness on cards being filled in, input and audited showed increase of 8.44%, 6.76% and 2.40% respectively.

CONCLUSIONSuccessful measures for prevention and control on typhoid fever and paratyphoid fever had been remarkably taken in Guizhou province, but the potential risk of outbreaks still existed in some areas, suggesting that health education and surveillance programs including laboratory diagnosis, should be strengthened.

China ; epidemiology ; Communicable Disease Control ; methods ; Humans ; Paratyphoid Fever ; epidemiology ; prevention & control ; Typhoid Fever ; epidemiology ; prevention & control

Typhoid fever, a serious systemic infection caused by Salmonella enterica serovar Typhi, breaks out in developing countries. However, existing vaccines only induce relatively low protective effects with humoral responses and do not stimulate secondary immune response, especially to young people. The objective of this study is to evaluate the immunogenicity of the vaccine containing virulence capsular polysaccharide (Vi) conjugated with the optimal ratios of non-toxic variant of diphtheria toxin (CRM(197)) in mice. Six-week-old BALB/c female mice were injected intraperitoneally three times at intervals of 14 days and sera were collected on days 0, 14, 28, 42 and 56 post-injection. The efficacy of the vaccine was evaluated by comparing between negative control group injected with PBS and vaccine groups injected with Vi or Vi-CRM(197) conjugate of different ratio. Vi and CRM(197)-specific antibody responses were evaluated using enzyme-linked immunosorbent assay. The result showed that Vi-CRM(197)-1 group revealed the highest and significant Vi-specific IgG immune responses among the other groups and Vi group (p < 0.01). In conclusion, Vi-CRM(197)-1 conjugate vaccine induced the highest humoral immune response in mice and may be used as an effective vaccine to replace the existing typhoid vaccine for infants under 2 years old.
Animals ; Antibody Formation ; Child, Preschool ; Developing Countries ; Diphtheria Toxin ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunity, Humoral ; Immunoglobulin G ; Infant ; Mice* ; Salmonella enterica* ; Salmonella typhi* ; Salmonella* ; Typhoid Fever ; Typhoid-Paratyphoid Vaccines ; Vaccines ; Virulence

BACKGROUNDTyphoid/paratyphoid fever (TPF) is endemic in Guizhou. We conducted wavelet analysis and Spearman's rank correlation analysis to explore the impact of meteorological variations on TPF infection in Guizhou, in an attempt to assess the risk factors associated with TPF epidemics.

METHODSWe examined the association between TPF incidence in Guizhou and temperature, precipitation and relative humidity using 24 years of data from 1984 to 2007. Periodicities of TPF incidence and the impact of climate factors on the TPF were detected by Spearman's rank correlation and wavelet analysis,

RESULTSTemperature and precipitation with a 1-month lag were positively correlated with the monthly incidence of TPF. The multiyear incidence pattern of TPF in Guizhou was explicitly periodic. Moreover, the association and driving effect of precipitation on TPF were observed, and the results showed that the incidence of TPF in Guizhou had a closer correlation with precipitation than with temperature.

CONCLUSIONSSafe water supply is the key issue for TPF control in Guizhou. Moreover, climate variation might impact the enteric infections, which may inform policy assessment for TPF control in Guizhou.

China ; epidemiology ; Humans ; Incidence ; Paratyphoid Fever ; epidemiology ; Rain ; Temperature ; Typhoid Fever ; epidemiology

INTRODUCTIONEnteric fever is a common infection in endemic areas; however, there are few reports describing the computed tomography (CT) manifestations of enteric fever. We aim to describe and illustrate CT findings in enteric fever in this study.

MATERIALS AND METHODSA retrospective search of medical records in our institute for patients with positive blood cultures for Salmonella typhi, and Salmonella paratyphi organisms yielded 39 cases. Among these patients, 12 had undergone a CT study of the abdomen. The CT images, laboratory and clinical findings of these 12 patients were reviewed.

RESULTSThe most common clinical presentation was fever (100%). Typical features of gastroenteritis were present in only over half of the patients. Liver function tests were abnormal in all patients. The most common abdominal manifestations on CT were the presence of mesenteric lymphadenopathy and splenomegaly (75%). Other features were circumferential small bowel wall thickening (58.3%) and free intraperitoneal fluid (50%). Three patients were found to have complications; one with bleeding from terminal ileal ulceration, another with an ileal perforation and the third with renal abscess formation.

CONCLUSIONCT is useful in evaluating enteric fever in patients with severe forms of presentation, a longer clinical course or less specific symptoms. Although the imaging features overlap with other abdominal infections, when combined with clinical features, travel history to endemic areas and presence of transaminitis, the diagnosis of enteric fever should be considered. CT in particular, is useful for the detection of complications such as perforation, bleeding and abscess formation.

Abscess ; diagnostic imaging ; Adolescent ; Adult ; Aged ; Ascitic Fluid ; diagnostic imaging ; Child ; Child, Preschool ; Female ; Humans ; Intestine, Small ; diagnostic imaging ; Lymphatic Diseases ; diagnostic imaging ; Male ; Middle Aged ; Paratyphoid Fever ; diagnostic imaging ; Radiography, Abdominal ; Retrospective Studies ; Salmonella paratyphi A ; Salmonella paratyphi B ; Salmonella typhi ; Splenomegaly ; diagnostic imaging ; Tomography, X-Ray Computed ; Typhoid Fever ; diagnostic imaging

The purpose of the study was to collect the opinions of doctors who are specialists in infectious disease with regard to the current method used for isolation of patients with group 1 nationally notifiable infectious diseases in Korea. A web-based survey was conducted from June 27 to July 7, 2011. Relevant questions included: 1) adequacy of the current policy of forced hospital isolation; evaluation of current guidelines for release from hospital isolation; and 3) priority for policy switching from forced hospital isolation to home isolation. The rate of response to the survey was 28.4% (40 out of 140). First, the majority of infectious disease specialists in Korea believed that the current method of forced hospital isolation for patients with group 1 infectious diseases should be changed to the home isolation method. Second, if the Korean government changes its policy to home isolation, the top priority of the policy switch would be typhoid fever, followed by paratyphoid fever, shigellosis, cholera, and EHEC (enterohemorigic Escherichia coli). Regarding current guidelines for release from hospital isolation, in cases of shigellosis, EHEC, and hepatitis A, the majority of respondents supported the current guidelines, while they were not able to make collective opinions in cases of cholera and typhoid/paratyphoid fever. We were able to confirm that the majority of specialists want to change the current isolation method. Therefore, the Korean government should consider switching their policy from forced hospital isolation to home isolation.
Cholera ; Communicable Diseases ; Dysentery, Bacillary ; Enterohemorrhagic Escherichia coli ; Escherichia ; Fever ; Hepatitis A ; Humans ; Infectious Disease Medicine ; Korea ; Paratyphoid Fever ; Specialization ; Surveys and Questionnaires ; Typhoid Fever