Incidence Estimates of Acute Q Fever and Spotted Fever Group Rickettsioses, Kilimanjaro, Tanzania, from 2007 to 2008 and from 2012 to 2014.

Q fever and spotted fever group rickettsioses (SFGR) are common causes of severe febrile illness in northern Tanzania. Incidence estimates are needed to characterize the disease burden. Using hybrid surveillance-coupling case-finding at two referral hospitals and healthcare utilization data-we estimated the incidences of acute Q fever and SFGR in Moshi, Kilimanjaro, Tanzania, from 2007 to 2008 and from 2012 to 2014. Cases were defined as fever and a four-fold or greater increase in antibody titers of acute and convalescent paired sera according to the indirect immunofluorescence assay of Coxiella burnetii phase II antigen for acute Q fever and Rickettsia conorii (2007-2008) or Rickettsia africae (2012-2014) antigens for SFGR. Healthcare utilization data were used to adjust for underascertainment of cases by sentinel surveillance. For 2007 to 2008, among 589 febrile participants, 16 (4.7%) of 344 and 27 (8.8%) of 307 participants with paired serology had Q fever and SFGR, respectively. Adjusted annual incidence estimates of Q fever and SFGR were 80 (uncertainty range, 20-454) and 147 (uncertainty range, 52-645) per 100,000 persons, respectively. For 2012 to 2014, among 1,114 febrile participants, 52 (8.1%) and 57 (8.9%) of 641 participants with paired serology had Q fever and SFGR, respectively. Adjusted annual incidence estimates of Q fever and SFGR were 56 (uncertainty range, 24-163) and 75 (uncertainty range, 34-176) per 100,000 persons, respectively. We found substantial incidences of acute Q fever and SFGR in northern Tanzania during both study periods. To our knowledge, these are the first incidence estimates of either disease in sub-Saharan Africa. Our findings suggest that control measures for these infections warrant consideration.

A Systematic Review and Meta-analysis of the Prevalence of Community-Onset Bloodstream Infections among Hospitalized Patients in Africa and Asia.

Community-onset bloodstream infections (CO-BSI) are major causes of severe febrile illness and death worldwide. In light of new data and the growing problem of antimicrobial resistance (AMR) among pathogens causing BSI, we undertook a systematic review of hospital-based studies of CO-BSI among patients hospitalized with fever. Without restriction to language or country, we searched PubMed, Web of Science, and Scopus for prospective hospital-based studies of culture-confirmed CO-BSI among febrile inpatients. We determined by study the prevalence of BSI among participants, the pathogens responsible for BSI, and the antimicrobial susceptibility patterns of pathogens causing BSI, according to place and time. Thirty-four (77.3%) of 44 eligible studies recruited 29,022 participants in Africa and Asia combined. Among participants in these two regions, the median prevalence of BSI was 12.5% (range, 2.0 to 48.4%); of 3,220 pathogens isolated, 1,119 (34.8%) were Salmonella enterica, 425 (13.2%) Streptococcus pneumoniae, and 282 (8.8%) Escherichia coli Antimicrobial susceptibility testing was reported in 16 (36.4%) studies. When isolates collected prior to 2008 were compared to those collected in the period of 2008 through 2018, the proportions of typhoidal Salmonella and Staphylococcus aureus isolates resistant to several clinically relevant antimicrobials increased over time, while S. pneumoniae susceptibility was stable. CO-BSI remain a major cause of severe febrile illness among hospitalized patients in Africa and Asia, with S. enterica, S. pneumoniae, and E. coli predominating. There is a concerning increase in AMR among serious infections caused by community-onset pathogens. Ongoing surveillance is needed to inform empirical management and strategies to control AMR.

Using hospital-based studies of community-onset bloodstream infections to make inferences about typhoid fever incidence.

OBJECTIVES: Hospital-based studies of community-onset bloodstream infections (CO-BSI) are less resource-intensive to carry out than population-based incidence studies. We examined several metrics capturing the potential role of Salmonella Typhi as a cause of CO-BSI for making inferences about incidence. METHODS: We systematically reviewed three databases for hospital-based studies of CO-BSI. We determined, by study, the prevalence and rank order of Salmonella among pathogenic bloodstream isolates, and the prevalence ratio of Salmonella Typhi to Escherichia coli (S:E ratio). We then describe these hospital-based study metrics in relation to population-based typhoid fever incidence data from a separate systematic review. RESULTS: Forty-four studies met the inclusion criteria, of which 23 (52.3%) isolated Salmonella Typhi at least once. Among studies isolating Salmonella Typhi, the median (interquartile range) prevalence and rank order of Salmonella Typhi compared to other pathogens isolated in BSI was 8.3% (3.2-37.9%) and 3 (1-6), respectively. The median (interquartile range) S:E ratio was 1.0 (0.4-3.0). With respect to incidence, in Pemba Island, Tanzania, prevalence, rank order, S:E ratio, and incidence was 64.8%, 1, 9.2 and 110 cases per 100 000, respectively, and in Boulkiemdé, Burkina Faso, was 13.3%, 3, 2.3 and 249 cases per 100 000. CONCLUSIONS: We describe considerable variation in place and time for Salmonella Typhi prevalence, rank order, and S:E ratio among hospital-based studies of CO-BSI. Data from simultaneous typhoid prevalence and incidence studies are limited. We propose that hospital-based study metrics warrant evaluation for making inference about typhoid incidence and as covariates in typhoid incidence models.

OBJECTIFS: Les études hospitalières d'infections d'origine sanguine acquises dans la communauté (IS-AC) consomment moins de ressources que les études d'incidence basées sur la population. Nous avons examiné plusieurs paramètres permettant de déterminer le rôle de Salmonella typhi comme cause des IS-AC pour permettre des déductions sur l'incidence. MÉTHODES: Nous avons systématiquement passé en revue trois bases de données sur des études hospitalières d'IS-AC. Par étude, nous avons déterminé la prévalence et l'ordre de classement de Salmonella parmi les isolats de pathogènes sanguins, ainsi que le rapport de prévalence de Salmonella typhi et Escherichia coli (rapport S:E). Nous décrivons ensuite ces résultats d'étude en milieu hospitalier en relation avec les données d'incidence de la fièvre typhoïde basées sur la population, tirées d'une revue systématique distincte. RÉSULTATS: Quarante-quatre études remplissaient les critères d'inclusion, dont 23 (52,3%) avaient isolé au moins une fois Salmonella typhi. Parmi les études isolant Salmonella typhi, la prévalence médiane (intervalle interquartile) et l'ordre de classement de Salmonella typhi par rapport aux autres agents pathogènes isolés de sangs étaient de 8,3% (3,2 à 37,9%) et de 3 (1-6), respectivement. Le rapport S:E médian (intervalle interquartile) était de 1,0 (0,4 à 3,0). En ce qui concerne l'incidence, sur l'île de Pemba, en Tanzanie, la prévalence, l'ordre de classement, le rapport S:E et l'incidence étaient respectivement de 64,8% ; 1 ; 9,2 et 110 cas pour 100.000, et dans le Boulkiemdé, au Burkina Faso, de 13,3% ; 3 ; 2,3 et 249 cas pour 100.000 habitants. CONCLUSIONS: Nous décrivons une variation considérable selon le lieu et le moment de la prévalence, de l'ordre de classement et du rapport S:E de Salmonella typhi parmi les études hospitalières sur les IS-AC. Les données provenant d'études simultanées sur la prévalence et l'incidence de la typhoïde sont limitées. Au vu des variations, nous proposons que les métriques d'étude en milieu hospitalier soient évaluées en tant que covariables dans les modèles de détermination de l'incidence de la typhoïde.