occupation." Overall, in the early 20th century the medical profession began to identify carriers of the disease, and evidence of transmission independent of water contamination. In a 1933 American Medical Association publication, physicians' treatment of asymptomatic carriers is best summarized by the opening line "Carriers of typhoid bacilli are a menace". Within the same publication, the first official estimate of typhoid carriers is given: 2 to 5% of all typhoid patients, and distinguished between temporary carriers and chronic carriers. The authors further estimate that there are four to five chronic female carriers to every one male carrier, although offered no data to explain this assertion of a gender difference in the rate of typhoid carriers. As far as treatment, the authors suggest: "When recognized, carriers must be instructed as to the disposal of excreta as well as to the importance of personal cleanliness. They should be forbidden to handle food or drink intended for others, and their movements and whereabouts must be reported to the public health officers". Today, typhoid carriers exist all over the world, but the highest incidence of asymptomatic infection is likely to occur in South/Southeast Asian and Sub-Saharan countries. The Los Angeles County department of public health tracks typhoid carriers and reports the number of carriers identified within the county yearly; between 2006 and 2016 0-4 new cases of typhoid carriers were identified per year. Cases of typhoid fever must be reported within one working day from identification. As of 2018, chronic typhoid carriers must sign a "Carrier Agreement" and are required to test for typhoid shedding twice yearly, ideally every 6 months. Carriers may be released from their agreements upon fulfilling "release" requirements, based on completion of a personalized treatment plan designed with medical professionals. Fecal or gallbladder carrier release requirements: 6 consecutive negative feces and urine specimens submitted at 1-month or greater intervals beginning at least 7 days after completion of therapy. Urinary or kidney carrier release requirements: 6 consecutive negative urine specimens submitted at 1-month or greater intervals beginning at least 7 days after completion of therapy. As of 2016 the male:female ratio of carriers in Los Angeles county was 3:1. Due to the nature of asymptomatic cases, many questions remain about how individuals are able to tolerate infection for long periods of time, how to identify such cases, and efficient options for treatment. Researchers are currently working to understand asymptomatic infection with