Typhoid Fever: Way Forward.

The Tackling Typhoid supplement shows that typhoid fever continues to be a problem globally despite socioeconomic gains in certain settings. Morbidity remains high in many endemic countries, notably in sub-Saharan Africa and South Asia. In addition, antimicrobial resistance is a growing issue that poses a challenge for clinical management. The findings from this supplement revealed that outside of high-income countries, there were few reliable population-based estimates of typhoid and paratyphoid fever derived from surveillance systems. This indicates the need for monitoring systems that can also characterize the effectiveness of interventions, particularly in low- and middle-income settings. The country case studies indicated that gains in economic conditions, education, and environmental health may be associated with reductions in typhoid fever burden. Over the study period, the effect is mainly notable in countries with higher baseline levels of economic development, female literacy, and investments in public sanitation. High burden countries must continue to invest in strategies at the local level to address environmental factors such as access to safe drinking water and improved public sanitation that are known to interrupt transmission or diminish the risk of acquiring typhoid. Developing more effective vaccines and incorporating appropriate immunization strategies that target populations with the greatest risk could potentially alleviate disease burden.

Global Trends in Typhoidal Salmonellosis: A Systematic Review.

Typhoid and paratyphoid fever continue to significantly contribute to global morbidity and mortality. Disease burden is higher in low-and middle-income settings where surveillance programs are rare and little systematic information exists at population level. This review evaluates national, regional, and global trends in the incidence of typhoid fever and of related morbidity and mortality. A literature search in Medline, Embase, and Web of Science was conducted in June 2016, followed by screening and data extraction in duplicate. Studies reporting blood culture estimates of typhoid or paratyphoid morbidity and mortality were included in the analysis. Our search yielded 5,563 unique records, of which 1978 were assessed for relevance with 219 records meeting the eligibility criteria. Salmonella enterica serotype Typhi was the most commonly reported organism (91%), with the occurrence of typhoidal Salmonella (either incidence or prevalence) being the most commonly reported outcome (78%), followed by typhoid fever mortality, ileal perforation morbidity, and perforation mortality, respectively. Fewer than 50% of studies stratified outcomes by age or urban/rural locality. Surveillance data were available from 29 countries and patient-focused studies were available from 32 countries. Our review presents a mixed picture with declines reported in many regions and settings but with large gaps in surveillance and published data. Regional trends show generally high incidence rates in South Asia, sub-Saharan Africa, and East Asia and Pacific where the disease is endemic in many countries. Significant increases have been reported in certain countries but should be explored in the context of long-term trends and underlying at-risk populations.

Integration of enteric fever surveillance into the WHO-coordinated Invasive Bacterial-Vaccine Preventable Diseases (IB-VPD) platform: A low cost approach to track an increasingly important disease.

BACKGROUND: Lack of surveillance systems and accurate data impede evidence-based decisions on treatment and prevention of enteric fever, caused by Salmonella Typhi/Paratyphi. The WHO coordinates a global Invasive Bacterial-Vaccine Preventable Diseases (IB-VPD) surveillance network but does not monitor enteric fever. We evaluated the feasibility and sustainability of integrating enteric fever surveillance into the ongoing IB-VPD platform. METHODOLOGIES: The IB-VPD surveillance system uses WHO definitions to enroll 2-59 month children hospitalized with possible pneumonia, sepsis or meningitis. We expanded this surveillance system to additionally capture suspect enteric fever cases during 2012-2016, in two WHO sentinel hospitals of Bangladesh, by adding inclusion criteria of fever ≥102°F for ≥3 days, irrespective of other manifestations. Culture-positive enteric fever cases from in-patient departments (IPD) detected in the hospital laboratories but missed by the expanded surveillance, were also enrolled to assess completion. Costs for this integration were calculated for the additional personnel and resources required. PRINCIPAL FINDINGS: In the IB-VPD surveillance, 5,185 cases were enrolled; 3% (N = 171/5185) were positive for microbiological growth, of which 55% (94/171) were culture-confirmed cases of enteric fever (85 Typhi and 9 Paratyphi A). The added inclusion criteria for enteric fever enrolled an additional 1,699 cases; 22% (358/1699) were positive, of which 85% (349/358) were enteric fever cases (305 Typhi and 44 Paratyphi A). Laboratory surveillance of in-patients of all ages enrolled 311 additional enteric fever cases (263 Typhi and 48 Paratyphi A); 9% (28/311) were 2-59 m and 91% (283/311) >59 m. Altogether, 754 (94+349+311) culture-confirmed enteric fever cases were found, of which 471 were 2-59 m. Of these 471 cases, 94% (443/471) were identified through the hospital surveillances and 6% (28/471) through laboratory results. Twenty-three percent (170/754) of all cases were children <2 years. Additional cost for the integration was USD 44,974/year, a 27% increase to the IB-VPD annual expenditure. CONCLUSION: In a setting where enteric disease is a substantial public health problem, we could integrate enteric fever surveillance into the standard IB-VPD surveillance platform at a modest cost.

[Burden of disease regarding paratyphoid fever A - based on the Syndromic Surveillance System on Fever].

OBJECTIVE: To evaluate the burden of paratyphoid fever A in Hongta district, Yuxi city, Yunnan province from May 1, 2008 to April 30, 2009 so as to provide information for the development of comprehensive intervention measures. METHODS: Based on the Fever Syndromic Surveillance System, information as attendance rate of patients with fever, rate of patients being sampled, laboratory testing rate, sensitivity on the detection of blood culture and the rate of case reporting etc. were calculated. According to the pyramid model of food-borne disease on disease burden, the local actual incidence of paratyphoid fever A was estimated and analyzed. RESULTS: Under the Fever Syndromic Surveillance System, there were 6642 fever cases being detected, among whom 6570 cases were sampled and undergone testing, with the sampling rate as 98.92% and all the samples received laboratory testing. There were 354 positive cases of paratyphoid fever A reported, all from the Hongta district. Data showed that the attendance rate of the feverish patients was 73.53%, with the highest rate seen in whose under 10 years old (100%). Assumed that the sensitivity of paratyphoid fever blood culture was 70%, and the case reporting rate was 90%, we estimated that the annual incidence of paratyphoid fever A in Hongta was 220.33 (95%CI: 170.1 - 521.4) per 100 thousand, with 965 (95%CI: 745 - 2284) as new cases. Among all the age groups, the incidence in the age group from 15 to 44 years old was estimated to be at the highest (318.27 per 100 thousand). CONCLUSION: Hongta seemed to be an endemic region for paratyphoid fever A, with the highest incidence occurred in the age group of between 15 and 44 years old. These findings highlighted the urgent need to carry out further investigation on the risk factors and to implement targeted effective prevention and control measures.