C. serovar Typhi (Typhi) is the cause of typhoid fever. Typhi may be transmitted through dropping in the stool, which can continue after recovery from acute illness. Shedding is definitely recognized by culturing stool, which GSK726701A is demanding to co-ordinate at level. We hypothesised that sero-surveillance would direct us to the people dropping Typhi in stool following a typhoid outbreak. Methods In 2016 a typhoid outbreak affected one in four occupants of a Nursing School in Malosa, Malawi. The Division of Health asked for assistance to determine nursing students that might spread the outbreak to additional health facilities. We measured IgG antibody titres against Vi capsular polysaccharide (anti-Vi IgG) and IgM / IgG antibodies against H:d flagellin (anti-H:d) three and six months after the outbreak. We selected participants in the highest and least expensive deciles for anti-Vi IgG titre (measured at check out one) and acquired stool for tradition and PCR. All participants reported whether they experienced experienced fever persisting for three days or more during the outbreak (in keeping with the WHO meanings of suspected typhoid). We tested for salmonellae in the Nursing School environment. Results We acquired 320 combined serum samples from 407 occupants. We cultured stool from 25 occupants with high anti-Vi IgG titres and 24 occupants with low titres. We did not recover Typhi from stool; four stool samples yielded non-typhoidal salmonellae; one sample produced a positive PCR amplification for any Typhi target. Median anti-Vi and anti-H:d IgG titres fell among participants who reported prolonged fever. There was a smaller fall in anti-H:d GSK726701A IgG titres among participants who did not report prolonged fever. Non-typhoidal salmonellae were identified in water GSK726701A sampled at resource and from a kitchen faucet. Conclusion Large titres of anti-Vi IgG did not identify culture-confirmed dropping of Typhi. There was a definite serologic transmission of recent typhoid exposure in the cohort, displayed by waning IgG antibody titres over time. The presence of non-typhoidal salmonellae in drinking water shows sub-optimal sanitation. Developing methods to detect and Rabbit polyclonal to ZNF286A treat dropping remains an important priority to complement typhoid conjugate vaccination in attempts to accomplish typhoid removal. Supplementary Information The online version consists of supplementary material available at 10.1186/s12879-023-08385-8. Keywords: GSK726701A Typhoid, Typhi, Shedding, Sero-surveillance, Outbreak Background It is estimated that 1.5?million cases of typhoid fever occurred in Africa (excluding North Africa) GSK726701A in 2017 [1]. Whilst this number represents a fall in incidence estimations from 1990, localised outbreaks [2C5] map closely to the emergence of genotypes associated with multi-drug resistance (MDR) [6]. Mathematical modelling suggests such outbreaks may be driven by improved transmissibility associated with drug resistant phenotypes [7]. Where serovar Typhi (Typhi) is definitely inadequately treated, ongoing dropping is more likely; it is important to detect this in order to break the transmission cycle. Although stool tradition remains the standard test to identify Typhi dropping, it lacks level of sensitivity [8]. The relative contribution of temporary shedders to ongoing transmission remains unclear, but is likely to play a larger part in high incidence settings [9, 10]. Serology has been used to complement an outbreak investigation in countries where typhoid is not endemic, resulting in candidate shedders becoming successfully recognized by high anti-Vi antibody titre (anti-Vi IgG) followed by isolation of Typhi in stool [11, 12]. Anti-Vi antibody titres have been used in efforts to identify service providers in endemic populations (outside of the context of an outbreak), but have led to little recovery of Typhi [13C15]. Antibody to flagellin (anti-H:d) is definitely a component of the Widal test, and has been proposed as a possible diagnostic marker for typhoid fever [16C19]. Anti-H:d has not previously.