Prediction of Shigellosis outcomes in Israel using machine learning classifiers.

Shigellosis causes significant morbidity and mortality in developing and developed countries, mostly among infants and young children. The World Health Organization estimates that more than one million people die from Shigellosis every year. In order to evaluate trends in Shigellosis in Israel in the years 2002-2015, we analysed national notifiable disease reporting data. Shigella sonnei was the most commonly identified Shigella species in Israel. Hospitalisation rates due to Shigella flexenri were higher in comparison with other Shigella species. Shigella morbidity was higher among infants and young children (age 0-5 years old). Incidence of Shigella species differed among various ethnic groups, with significantly high rates of S. flexenri among Muslims, in comparison with Jews, Druze and Christians. In order to improve the current Shigellosis clinical diagnosis, we developed machine learning algorithms to predict the Shigella species and whether a patient will be hospitalised or not, based on available demographic and clinical data. The algorithms' performances yielded an accuracy of 93.2% (Shigella species) and 94.9% (hospitalisation) and may consequently improve the diagnosis and treatment of the disease.

Disparities in severe shigellosis among adults - Foodborne diseases active surveillance network, 2002-2014.

BACKGROUND: Shigella causes approximately 500,000 illnesses, 6000 hospitalizations, and 40 deaths in the United States annually, but incidence and populations at risk for severe shigellosis among adults are unclear. This study describes severe shigellosis among US adults. METHODS: We analyzed Foodborne Diseases Active Surveillance Network data for infections caused by Shigella among adults ≥18 years old during 2002-2014. Criteria to define severe shigellosis included hospitalization, bacteremia, or death. We estimated annual incidence of shigellosis per 100,000 among adult populations, and conducted multivariable mixed-effects logistic regression to assess associations between severe shigellosis, demographic factors and Shigella species among adults with shigellosis. RESULTS: Among 9968 shigellosis cases, 2764 (28%) were severe. Restricting to cases due to S. sonnei and S. flexneri, median annual incidence of severe shigellosis among adults was 0.56 and highest overall incidence was among black males 18-49 years old (1.58). Among adults with shigellosis, odds of severe disease were higher among males than females aged 18-49 years old (OR [95% CI] = 1.32 [1.15-1.52], p < 0.001) and among males than females with S. flexneri infections (OR [95% CI] =1.39 [1.10-1.75], p = 0.005). The odds of severe shigellosis were higher among blacks than whites (OR [95% CI] = 1.36 [1.22-1.52], p < 0.001). CONCLUSIONS: Among adults, men 18-49 years old, particularly blacks, have the highest incidence of severe shigellosis. Among adults with shigellosis, severe shigellosis was associated with being male in age group 18-49 years, with infections caused by S. flexneri, and with black race. Future research should assess associations between severe shigellosis and sexual practices, antimicrobial resistance, comorbidities, and access to care.

Antimicrobial susceptibility patterns of Shigella isolates in Foodborne Diseases Active Surveillance Network (FoodNet) sites, 2000-2010.

BACKGROUND: Treatment of shigellosis with appropriate antimicrobial agents shortens duration of illness and bacterial shedding, but resistance to commonly used agents is increasing. METHODS: We describe resistance patterns among Shigella isolates in the United States with use of linked data from the Foodborne Diseases Active Surveillance Network (FoodNet) and National Antimicrobial Resistance Monitoring System (NARMS). FoodNet sites send every 20th Shigella isolate to the NARMS laboratory for susceptibility testing. RESULTS: During 2000-2010, the NARMS laboratory tested 1376 Shigella isolates from FoodNet sites. Of 1118 isolates (81%) linked to FoodNet, 826 (74%) were resistant to ampicillin, 649 (58%) to streptomycin, 402 (36%) to trimethoprim-sulfamethoxazole (TMP-SMX), 355 (32%) to sulfamethoxazole-sulfisoxazole, 312 (28%) to tetracycline, 19 (2%) to nalidixic acid, and 6 (0.5%) to ciprofloxacin. The proportion of Shigella isolates with resistance to TMP-SMX was 40% among white persons, 58% among Hispanic persons, and 75% among persons with a history of international travel. Resistance to at least TMP-SMX and ampicillin was present in 25% of isolate, and 5% were resistant to ampicillin, TMP-SMX, and chloramphenicol. Overall, 5% of isolates showed multidrug resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole-sulfisoxazole, and tetracycline, including 49 Shigella flexneri (33%) and 3 Shigella sonnei (0.3%) isolates. Male individuals were more likely than female individuals to be infected with a multidrug-resistant strain (7% versus 3%; P < .01). CONCLUSIONS: Antimicrobial resistance differed by race, ethnicity, age, travel, and species. Resistance to commonly used antibiotics is high; therefore, it is important to look at the susceptibility pattern before starting treatment.

Incidence of Shigella intestinal infections, active component, U.S. Armed Forces, 2007-2016.

During 2007-2016, there were 428 incident cases of Shigella infection among active component service members, with an overall crude incidence rate of 3.4 cases per 100,000 person-years (p-yrs). Compared to their respective counterparts, overall incidence rates were highest among females, non-Hispanic black service members, those aged 35-39 years, members of the Army, and those in military healthcare occupations. With the exception of 2015, the annual incidence rates of shigellosis from 2007 through 2016 were relatively stable. The annual incidence rate in 2015 was twice that of the rate in 2014 (6.4 cases per 100,000 p-yrs and 3.1 cases per 100,000 p-yrs, respectively). This peak was followed by a decrease to 3.4 cases per 100,000 p-yrs in 2016. There was no marked pattern of seasonality of Shigella infections during the 10-year surveillance period. During 2008-2016, a total of 23 cases of Shigella infection were diagnosed in deployment settings. Risk factors for Shigella infection and standard measures for the prevention of shigellosis are reviewed.

[Influence of humidex on incidence of bacillary dysentery in Hefei: a time-series study].

Objective: To investigate the effect of humidex combined with mean temperature and relative humidity on the incidence of bacillary dysentery in Hefei. Methods: Daily counts of bacillary dysentery cases and weather data in Hefei were collected from January 1, 2006 to December 31, 2013. Then, the humidex was calculated from temperature and relative humidity. A Poisson generalized linear regression combined with distributed lag non-linear model was applied to analyze the relationship between humidex and the incidence of bacillary dysentery, after adjusting for long-term and seasonal trends, day of week and other weather confounders. Stratified analyses by gender, age and address were also conducted. Results: The risk of bacillary dysentery increased with the rise of humidex. The adverse effect of high humidex (90 percentile of humidex) appeared in 2-days lag and it was the largest at 4-days lag (RR=1.063, 95%CI: 1.037-1.090). Subgroup analyses indicated that all groups were affected by high humidex at lag 2-5 days. Conclusion: High humidex could significantly increase the risk of bacillary dysentery, and the lagged effects were observed.

Laboratory-confirmed shigellosis in the United States, 1989-2002: epidemiologic trends and patterns.

During 1989-2002, a total of 208,368 laboratory-confirmed Shigella infections were reported to the Centers for Disease Control and Prevention. Shigella sonnei accounted for 71.7%, Shigella flexneri accounted for 18.4%, Shigella boydii accounted for 1.6%, and Shigella dysenteriae accounted for 0.7% of infections; for 7.6%, no serogroup was reported. National incidence rates ranged from 7.6 cases per 100,000 persons in 1993 to 3.7 cases per 100,000 persons in 1999. Incidence rates for S. boydii, S. dysenteriae, and S. flexneri decreased over the 14-year period by 81%, 83%, and 64%, respectively; S. sonnei rates only decreased by 8%. The highest rates were reported from western states (10.0 cases per 100,000 persons) and among children 1-4 years of age (20.6 cases per 100,000 persons). The female-male S. sonnei incidence rate ratio among 20-39-year-old adults decreased from 2.3 during 1989-1999 to 1.4 during 2000-2002. Approximately 1% of isolates were from extraenteric sources; 0.25% were from blood. S. sonnei remains an important cause of diarrhea in the United States. Prevention efforts that target high-risk groups are needed.

[Antibiotic sensitivity to epidemic strains of Vibrio cholerae and Shigella dysenteriae 1 isolated in Rwandan refugee camps in Zaire]. / Sensibilité aux antibiotiques de souches epidémiques de Vibrio cholerae et Shigella dysenteriae 1 isolées dans les camps de réfugiés rwandais au Zaïre.

Multiresistance or epidemic enteric bacteria to antibiotics greatly complicates treatment, and in some cases prophylaxis, of severe invasive gastroenteritis. During the summer of 1994, two epidemics of diarrhea, one due to Vibrio cholerae and the other to Shigella dysenteriae 1 isolated from the Goma and Bukavu camps was determined by measurement of the Agar Minimal Inhibitory Concentration. Multiresistance to tetracyclins, aminopenicillins, trimethoprimsulfamethoxazole, and nifuroxazide was observed. After intensive treatment mutant forms of both bacteria resistant to nalidixic acid rapidly appeared. Only fluoroquinolones remained active on these mutant strains, but the availability of this agent in Africa is restricted due to cost. The most effective way of preventing resistance is to limit the spread of enteric infections by health education and improvement of hygiene. This can be difficult during wartime.

Salmonella and Shigella carriers among refugees from the middle east and Sri Lanka in Denmark.

One per cent of ten thousand refugees were asymptomatic carriers of Salmonella and Shigella species found by a differentiated health check programme at a Danish Red Cross arrival centre in Denmark 1985 and 1986. Six patients with typhoid fever and one with S. parathyphi-A septicaemia all fell ill within the first few weeks after arrival. A child of a chronic S. typhi carrier developed typhoid fever four months after arrival. Cases of sporadic and mild diarrhoea occurred due to Salmonella and Shigella species. The carriers were instructed in prophylactic, hygienic measures and no outbreaks developed. The health check system in this period seemed to be sufficient in relation to preventing outbreaks of infections caused by non-typhoid Salmonella and Shigella species. The relative cost-effectiveness of a more intensive S. typhi screening on arrival is questionable. The organization of health check systems should be reviewed regularly, as each refugee situation is different and will change in different periods.

Hyperendemic shigellosis in the United States: a review of surveillance data for 1967-1988.

In 1988, 22,796 Shigella isolates were reported to the Centers for Disease Control, the highest number since national surveillance was begun in 1967. From 1986 to 1988, isolation rates increased from 5.4 to 10.1 per 100,000 persons. Increased isolation of Shigella sonnei, primarily among children and young women, occurred throughout the United States in a manner similar to the nationwide increase that occurred during the early 1970s. The highest rates during 1987-1988 were reported from countries with relatively high proportions of urban, ethnic ethnic minority, and poor residents, groups traditionally at high risk. The greatest percentage increases in isolation rates, however, occurred in relatively wealthy counties with predominantly white residents. Between 1967 and 1988, the proportion of Shigella species isolated from persons greater than or equal to 20 years of age increased 118%, while the proportion of the resident population in this age group increased only 16%. These data indicate a shift toward increased infection at older ages and the potential for periodic hyperendemic rates of shigellosis nationwide, which may be due to changing levels of immunity to S. sonnei.

Shigellosis on Indian reserves in Manitoba, Canada: its relationship to crowded housing, lack of running water, and inadequate sewage disposal.

OBJECTIVES: This study compares incidence and hospitalization rates for shigellosis between Indians and the rest of the population in Manitoba, Canada. It examines the relationship between shigellosis and environmental conditions on reserves. METHODS: Rates were calculated with surveillance data and a survey of environmental infrastructure was done. RESULTS: Indians had shigellosis incidence and hospitalization rates that were 29 and 12 times as high, respectively, as those of the rest of the population. Household crowding, lack of piped water, and inadequate sewage disposal were significantly associated with an increased incidence of shigellosis on reserves. CONCLUSIONS: Many cases of shigellosis may be prevented by improving living conditions on Indian reserves.

Epidemiology of Shigella infections in two ethnic groups in a geographic region in southern Israel.

The epidemiology of shigellosis in the Jewish and Bedouin populations that coexist in the same geographic region in southern Israel and share the same medical facilities but live separately under different socioeconomic conditions was examined in a retrospective, culture-based study. The average annual attack rate for the four-year period 1989-1992 was 368/100,000 inhabitants. The average annual attack rate among the Jews, who enjoy Western socioeconomic conditions, was 413/100,000 and the disease showed summer and winter peaks. Shigella sonnei caused 3,336 of 4,560 (73.2%) attacks in this group, and the attack rate of Shigella flexneri decreased during the study period. Among the Bedouins, many of whom live in poverty and overcrowding, a single annual summer peak was observed, the average annual attack rate being 197/100,000 and Shigella flexneri caused 389 of 583 episodes (66.7%). Resistance to ampicillin or tetracycline was noted in 57% of all Shigella isolates, and 82% were resistant to cotrimoxazole. It is concluded that shigellosis is highly endemic in southern Israel, resistance to antimicrobial drugs is common and living conditions of the population influence the seasonal occurrence of the disease and select for morbidity with specific organisms.