Characterization and factors associated with diarrhoeal diseases caused by enteric bacterial pathogens among children aged five years and below attending Igembe District Hospital, Kenya

Prevalence, associated factors and antimicrobial susceptibility patterns of Salmonella and Shigella species among diarrheic under five children in Sultan Sheik Hassan Yabere referral Hospital, Jigjiga, Eastern Ethiopia

BACKGROUND

Diarrhea caused by Salmonella and Shigella species are the leading cause of illness especially in developing countries. These infections are considered as the main public health problems in children, including Ethiopia. This study aimed to assess the prevalence, associated factors, and antimicrobial susceptibility patterns of Salmonella and Shigella species in Sheik Hassan Yabere Referral Hospital Jigjiga, Eastern Ethiopia from August 05 to November 15, 2022.

METHOD

A cross-sectional study was conducted among 239 under-five children with diarrhea selected through a convenient sampling technique. A structured questionnaire was used to collect associated factors. A stool sample was collected and processed for the identification of Salmonella and Shigella species using MacConkey adar, Xylose Lysine Deoxycholate agar (Oxoid Ltd) and Biochemical tests. The antimicrobial susceptibility pattern of isolates was performed using the Kirby-Bauer disc diffusion technique. The data was entered into Epi-data version 4.6 and exported to the statistical package of social science version 22 for analysis. The association between outcome and independent variables was assessed using bivariate, multivariable, and chi-square and P-value < 0.05 was considered as statistical significance.

RESULT

Overall prevalence of Salmonella and Shigella species was 6.3% (95% CI, 5.7-6.9%), of which 3.8% (95 CI, 3.2-4.4%) were Salmonella species and 2.5% (95% CI, 1.95-3%) were Shigella species. Unimproved water source (AOR = 5.08, 95% CI = 1.45, 17.25), open field (AOR = 2.3, 95% CI = 1.3, 5.03), rural residence (AOR = 1.8, 95% CI = 1.4, 7.5), Hand-washing practice (p = 0.001), and raw meat consumption (p = 0.002) were associated with occurrence of Salmonella and Shigella species. Salmonella and Shigella isolates were resistant to Ampicilin (100%). However, Salmonella isolates was sensitive to Norfloxacin (100%). About 22.2% and 16.7% of Salmonella and Shigella isolates were multi-drug resistant, respectively.

CONCLUSION

Prevalence of Salmonella and Shigella species were lower than most studies done in Ethiopia. Hand-washing habit, water source type, Open field waste disposal habit, raw meat consumption and rural residence were associated with Salmonellosis and shigellosis. All isolated Salmonella were sensitive to norfloxacin. The evidence from this study underscores the need for improved water, sanitation and hygiene (WASH) system and the imperative to implement drug susceptibility tests for the treatment of Salmonella and Shigella infection.

Age-dependent acquisition of IgG antibodies to Shigella serotypes-a retrospective analysis of seroprevalence in Kenyan children with implications for infant vaccination

Background

Shigellosis mainly affects children under 5 years of age living in low- and middle-income countries, who are the target population for vaccination. There are, however, limited data available to define the appropriate timing for vaccine administration in this age group. Information on antibody responses following natural infection, proxy for exposure, could help guide vaccination strategies.

Methods

We undertook a retrospective analysis of antibodies to five of the most prevalent Shigella serotypes among children aged <5 years in Kenya. Serum samples from a cross-sectional serosurvey in three Kenyan sites (Nairobi, Siaya, and Kilifi) were analyzed by standardized ELISA to measure IgG against Shigella sonnei and Shigella flexneri 1b, 2a, 3a, and 6. We identified factors associated with seropositivity to each Shigella serotype, including seropositivity to other Shigella serotypes.

Results

A total of 474 samples, one for each participant, were analyzed: Nairobi (n = 169), Siaya (n = 185), and Kilifi (n = 120). The median age of the participants was 13.4 months (IQR 7.0-35.6), and the male:female ratio was 1:1. Geometric mean concentrations (GMCs) for each serotype increased with age, mostly in the second year of life. The overall seroprevalence of IgG antibodies increased with age except for S. flexneri 6 which was high across all age subgroups. In the second year of life, there was a statistically significant increase of antibody GMCs against all five serotypes (p = 0.01-0.0001) and a significant increase of seroprevalence for S. flexneri 2a (p = 0.006), S. flexneri 3a (p = 0.006), and S. sonnei (p = 0.05) compared with the second part of the first year of life. Among all possible pairwise comparisons of antibody seropositivity, there was a significant association between S. flexneri 1b and 2a (OR = 6.75, 95% CI 3-14, p < 0.001) and between S. flexneri 1b and 3a (OR = 23.85, 95% CI 11-54, p < 0.001).

Conclusion

Children living in low- and middle-income settings such as Kenya are exposed to Shigella infection starting from the first year of life and acquire serotype-specific antibodies against multiple serotypes. The data from this study suggest that Shigella vaccination should be targeted to infants, ideally at 6 or at least 9 months of age, to ensure children are protected in the second year of life when exposure significantly increases.

Prevalence and Antimicrobial Susceptibility Profile of Salmonella and Shigella among Diarrheic Patients Attending Selected Health Facilities in Addis Ababa, Ethiopia

Diarrhea is one of the important public health problems in developing countries. Salmonella and Shigella species are the major bacterial causal agents of diarrhea. The increasing burden of antimicrobial resistance is posing difficulty in the treatment of these pathogens. This study aimed to assess the occurrence of Salmonella and Shigella in the feces of diarrheic patients receiving health services in Addis Ababa, Ethiopia, and to determine their antimicrobial susceptibility profile. A cross-sectional study involving 13 health centers was conducted where 428 diarrheic patients were recruited. Standard microbiology techniques were used to isolate Salmonella and Shigella from stool samples. In addition, Salmonella isolates were confirmed by polymerase chain reaction (PCR). The Kirby-Bauer disc diffusion method was employed to assess susceptibility to 11 antimicrobials for each of the Salmonella and Shigella isolates. The prevalence of Salmonella and Shigella spp. among diarrheic patients was 8.4%; n = 36 and 5.6%; n = 24, respectively. Thirty (83.3%) of Salmonella isolates were susceptible to all antimicrobials tested, whereas 4 (10.8%) of isolates were resistant to 2 or more antimicrobials and 2 (5.6%) were multidrug resistant. Resistance to ampicillin was recorded in only one (2.7%) of Salmonella isolates; however, resistance to ampicillin was recorded in 12 (50%) of the Shigella isolates. Half of the Shigella isolates (n = 12) were resistant to 2 or more antimicrobials while 5 (20.8%) of them were resistant to 3 or more antimicrobials. The overall rate of resistance to antimicrobials was more common in Shigella compared to Salmonella isolates. In conclusion, Salmonella and Shigella were isolated from the feces of diarrheic patients, with a higher rate of antimicrobial resistance in Shigella isolates, which could make the treatment of shigellosis challenging. Therefore, increasing hygienic practices during food preparation to reduce the burden of Salmonella and Shigella infection and prudent use of antimicrobials are recommended to limit the spread of antimicrobial resistant strains.

Antibiotic sensitivity profile of bacterial isolates from stool samples among children below five years in Murang'a County, Kenya

Introduction

the discovery of antibiotics led to the optimistic belief of completely eradicating infectious diseases during the golden era following their discovery. Countries are grappling with the burden of microbial resistance bringing a near paralysis of all facets of mankind. Enterobacteriaceae and other hard-to-treat Gram-negative bacteria have become resistant to nearly all antibiotic options available, and this is a bad taste in the fight against microbial resistance.

Methods

during the months of April-October 2017, 163 children below five years presenting with diarrhea were randomly selected in Murang´a and Muriranja´s Hospitals. Bacterial agents were identified and antibiotic susceptibility profile was determined. Design: a cross-sectional study approach was used. Statistical analyses were performed using STATA v. 13.

Results

a total of 188 bacteria belonging to 11 genera were isolated, and identified and their antibiotic susceptibility profiles were determined. Susceptibility testing showed that almost all the Enterotoxigenic Escherichia coli (ETEC), Enteropathogenic Escherichia coli (EPEC), Enteroaggregative Escherichia coli (EAEC), Salmonella, Klebsiella, Shigella, Vibrio, Enterobacter, Proteus, Pseudomonas, Aeromonas, Citrobacter and Yersinia species were resistant to the following antibiotics: ampicillin, amoxicillin, chloramphenicol, ciprofloxacin, ceftriaxone and kanamycin. Other than ETEC (90.9%), all the rest of the isolates were resistant to nalidixic acid. Other than ETEC (9.1%), EAEC (33.3%) and Salmonella species (95.2%), all the rest of the isolates were resistant to gentamicin. Other than V. cholerae, all the other isolates were resistant to trimethoprim-sulfamethoxazole. Isolates were sporadically resistant to erythromycin, streptomycin, doxycycline, and ofloxacin.

Conclusion

the high resistance rate of enteric Gram-negative bacterial pathogens in Murang´a County is alarming. The need for urgent, efficient, and sustainable actions and interventions, such as culture and susceptibility testing, is needed and must be taken into account to minimize and prevent the establishment and spread of enteric pathogenic bacteria.

The risk of water, sanitation and hygiene on diarrhea-related infant mortality in eastern Ethiopia: a population-based nested case-control

BACKGROUND

Diarrhea is still appeared to be as one of the leading global killers and disability-adjusted life-years lost, particularly in the infant and children. As per WHO, about 88% of diarrhea-related deaths are attributable to unsafe water, inadequate sanitation and insufficient hygiene, mainly in developing world. Thus, the main objective of this study was to find out the risk of such factors that contribute for diarrhea-related infant mortality in Eastern Ethiopia.

METHODS

This study employed community based unmatched nested case-control study design in Eastern Ethiopia. The cases were infants who died from diarrheal disease while controls were those who survived their first year of life from September, 2016 to August, 2018. A total of 305 study subjects (61 cases and 244 controls) were included in the study. Infants dying from diarrhea were compared to four neighborhood controls in terms of several risk components of Water, Sanitation and Hygiene. Data were collected from mothers/care takers of infants using pre-tested structured questionnaires, and entered onto CSpro version 5.1 and transform to SPSS version 23 to analyzed potential risk factors.

FINDINGS

Finding of this study revealed that the risk factors that found to be significantly associated with infant death from diarrhoea after adjustment for confounding variables included the age of mother with < 20 years old (P = 0.009, AOR: 0.01, 95% CI: 0.01, 0.47), unsafe drinking water storage (P = 0.013, AOR: 0.4, 95% CI: 0.18, 0.81), infants in households without point-of-use water treatment practices (P = 0.004, AOR: 0.21, 95% CI: 0.08, 0.61), households with unimproved sanitation (P = 0.050, AOR: 0.36, 95% CI: 0.13, 1.00), unsafe disposing of child feces (P = 0.014, AOR: 0.34, 95% CI: 0.15, 0.81), and improper management of solid waste (P = 0.003, AOR: 0.29, 95% CI: 0.13, 0.66). These exposure factors had lower risk for the contribution of infants dying from diarrhoea than those with their reference group in the study area. However, infants in households with improper management of liquid waste management showed strongly significant association which had three times more likely to occur diarrhea-related infant death (P = 0.010, AOR: 3.43, 95% CI: 1.34, 8.76). Similarly, infants whose mother/caretaker practiced hand washing with less critical time (one-two occasions) had three times greater risk to infant death from diarrhea than those who had practice more than three critical times of hand washing (P = 0.027, AOR: 3.04, 95% CI: 1.13, 8.17).

CONCLUSION

This study suggests that infants in households with improper management of liquid waste and hand washing practices with fewer occasions (one-two critical time) are a greater risk of getting a diarrhea-related infant death. Therefore, efforts should be made to ensure intervention taking such risk factors into consideration, typically in the infantile period.

Incidence, Demographic, and Seasonal Risk Factors of Infections Caused by Five Major Enteric Pathogens, Ontario, Canada, 2010-2017

In Canada, enteric infections cause significant health and economic burden. We evaluated the individual characteristics of laboratory-confirmed cases of Campylobacter spp. (n = 28,728), non-typhoidal Salmonella spp. (n = 22,640), Yersinia spp. (n = 1674), Verotoxin-producing Escherichia coli (VTEC; n = 1340), and Listeria monocytogenes (n = 471), reported between 2010 and 2017 inclusive, in Ontario, Canada (population ∼13,500,000). We calculated overall and pathogen-specific annual and mean incidence rates (IRs) for Ontario. We used multivariable Poisson and negative binomial regression models to estimate incidence rate ratios (IRRs) for years, seasons, age groups, and sexes, and we included two-way age and sex interaction terms in the models. Campylobacter and Salmonella infections had the highest IRs whereas Listeria infections had the lowest IRs. None of the infections showed long-term trends over the 8-year study period; however, rates of all five infections were elevated in the summer. More Salmonella, VTEC, and Listeria infections were linked to disease outbreaks than were Campylobacter and Yersinia infections. Overall, mean IRs of Campylobacter, Salmonella, Yersinia, and VTEC infections were highest in children 0-4 years old, whereas Listeria IRs peaked in adults 60 years and older. Higher mean IRs of Campylobacter were observed in males. No other differences by sex were statistically significant. The same mean rate was observed in both sexes for Listeria. Adjusting for all other factors, significant age- and sex-specific differences in IRs were observed in Campylobacter, Salmonella, and VTEC infection rates. No significant interactions of age and sex were found for Yersinia and Listeria infections. Future research should focus on the pathogen-specific socioeconomic, environmental, or agricultural risk factors that might be responsible for these infections.

Potential Influence of Regulation of the Food Value Chain on Prevalence and Patterns of Antimicrobial Resistance: the Case of Tilapia (Oreochromis niloticus)

The current study was designed to evaluate the potential impact of the level of regulation on the prevalence and patterns of antimicrobial agent resistance in bacteria isolated from fish. The study sites included two large lakes and both semiregulated and unregulated fish value chains. A total of 328 bacterial isolates belonging to 11 genera were evaluated for antimicrobial susceptibility testing using the disk diffusion method. The bacterial species were tested against 12 different antibiotics (trimethoprim-sulfamethoxazole, tetracycline, ampicillin, cefotaxime, chloramphenicol, nalidixic acid, amoxicillin, meropenem, ciprofloxacin, nitrofurantoin, cefuroxime, and kanamycin). Data analysis was done to assess the heterogeneity in proportion of resistant bacterial species within and between the two value chains using a random-effects model proposed by DerSimonian and Laird (Control Clin Trials 7:177-188, 1986). Statistical heterogeneity within and between groups was estimated using the Cochran chi-square test and the Cochrane I² index. The overall proportion of bacterial species resistant to antimicrobial agents in semiregulated and unregulated value chains ranged from 0.00 to 0.88 and 0.09 to 0.95, respectively. Shigella spp. had the highest proportion of bacteria that were resistant to most of the antimicrobial agents used. The bacterial species were highly resistant to ampicillin and amoxicillin, and the highest multidrug resistance capacity was observed in Shigella spp. (18.3%, n = 328), Vibrio spp. (18.3%), and Listeria monocytogenes (12.2%). We observed strong heterogeneity within and between the two value chains regarding proportion of resistant bacterial species. Sun-dried fish in both value chains had significantly high proportions of resistant bacterial species. Comparing the two value chains, the unregulated value chain had a significantly higher proportion of bacterial species that were resistant. In order to mitigate the risk of transmitting antimicrobial-resistant bacteria to consumers along the fish value chain, good manufacturing practices coupled with identification and management of possible sources of contamination are recommended for fish and potentially other foods distributed along the less regulated value chains. IMPORTANCE In order to mitigate the risk of transmitting antimicrobial-resistant bacteria to consumers along the fish value chain, good manufacturing practices coupled with identification and management of possible sources of contamination are recommended for fish and potentially other foods distributed along the less regulated value chains.

Frequency of five Escherichia Coli pathotypes in Iranian adults and children with acute diarrhea

Background

Knowledge about the distribution of Escherichia Coli (E. coli) pathotypes in Iran is limited. This nation-wide survey aims to provide a comprehensive description of the distribution of five pathogenic E. coli in Iran.

Methods

Stool samples were collected from 1,306 acute diarrhea cases from 15 provinces (2013–2014). E. coli-positive cultures underwent PCR testing for the detection of STEC, ETEC, EPEC, EAEC, and EIEC pathotypes. Pathotype frequency by province, age-group, and season was estimated.

Results

979 diarrhea samples (75.0%) were culture-positive for E. coli (95% CI: 72.6, 77.3%), and 659 (50.5%) were pathogenic E. coli (95% CI: 47.8, 53.2%). STEC was the most frequent pathotype (35.4%). ETEC (14.0%) and EPEC (13.1%) were the second and the third most frequent pathotypes, respectively. EAEC (4.3%) and EIEC (0.3%) were not highly prevalent. Fars (88.7%) and Khorasan-e-Razavi (34.8%) provinces had the highest and lowest frequencies, respectively. E. coli pathotypes were more frequent in warmer than cooler seasons, showed the highest frequency among children under five years of age (73%), and had no significant association with participants’ gender.

Conclusions

Diarrheagenic E. coli may be an important cause of acute diarrhea in adults and children in Iran. STEC and ETEC seem to be widespread in the country with a peak in warmer seasons, impacting the recommended use of seasonal STEC and ETEC vaccines, especially in high-risk groups. Monitoring the incidence of E. coli pathotypes, serotypes, and antibiotic resistance over time is highly recommended for evaluation of interventions.

Multiple drug resistance of Campylobacter jejuni and Shigella isolated from diarrhoeic children at Kapsabet County referral hospital, Kenya

Background

Diarrhoea is a common cause of mortality and morbidity in children under five years old. In Kenya, it has a 21% case fatality with Enteropathogenic E. coli, Campylobacter jejuni, Shigella spp. and Salmonella spp. accounting for 50–60% of the cases. Sulphonamides, tetracycline, ampicillin and trimethoprim/sulfamethoxazole are typically used in the treatment of diarrhoeal diseases but have become ineffective in the face of emerging antimicrobial resistance. The objective of this study was to evaluate the prevalence and antimicrobial susceptibility of Campylobacter jejuni and Shigella species in children under five years of age presenting with diarrhoea at Kapsabet County Referral Hospital in Kenya.

Methods

Faecal samples were collected from 139 children admitted with diarrhoea. Each sample was examined macroscopically for colour, texture, and presence of extraneous material. The samples were then cultured for bacterial growth. Observed bacterial growth was isolated and identified by a series of biochemical tests. Resistance patterns were also evaluated using the Kirby – Bauer Disk diffusion method. The chi – square test and Pearson Correlation Coefficient were used to establish statistical significance.

Results

Approximately 33.1% of the total faecal samples tested were positive for enteric pathogens. Shigella spp. demonstrated resistance to erythromycin (91.7%), doxycyclin (83.3%), ampicillin (82.1%), cotrimoxazole (73.1%), minocycline (66.7%) and cefuroxime (54.2%). Campylobacter jejuni also exhibited resistance to erythromycin (87.5%), doxycyclin (75%), ampicillin (73.7%), cotrimoxazole (73.3%) and minocycline (68.8%).

Conclusions

The resistance patterns of Shigella spp. and Campylobacter jejuni reported in this study necessitates the need for a comprehensive multiregional investigation to evaluate the geographical prevalence and antimicrobial resistance distributions of these microorganisms. These findings also support the need for the discovery and development of effective therapeutic alternatives.

Trial registration

Retrospectively registered. Certificate No. 00762

A pilot project: handwashing educational intervention decreases incidence of respiratory and diarrheal illnesses in a rural Malawi orphanage

Children who live in orphanages represent a population particularly vulnerable to transmissible diseases. Handwashing interventions have proven efficacy for reducing the rate of transmission of common infectious diseases. Few studies have analyzed the delivery of health interventions for children in orphanages in sub-Saharan Africa. To address this gap, we conducted an ecological assessment and piloted a handwashing intervention in an orphanage in rural Malawi, focusing on caregiver knowledge and behaviors, child handwashing behaviors, and disease incidence. A secondary study aim was to demonstrate program feasibility for a future randomized controlled trial. Orphanage caregivers participated in a three-module educational intervention on handwashing based on WHO recommendations and workshops on how to teach the curriculum to children. Seventeen orphanage caregivers and 65 children were monitored for handwashing behavior and child disease incidence. Friedman's tests were conducted to compare changes in caregiver knowledge and behaviors. Child handwashing behaviors and surveillance of child disease incidence were measured pre- and post-intervention. There were significant increases in caregiver hand hygiene knowledge. At six months post-intervention, handwashing with soap increased significantly among caregivers (p < 0.001) and was observed in children. The incidence of acute respiratory infections decreased from 30% to 6% post-intervention, resulting in an 80% decrease. The incidence of diarrhea decreased from 9.2% to 6.2% post-intervention, resulting in a 33% decrease. A brief educational intervention may improve handwashing knowledge and behaviors and help to decrease the incidence of common infectious diseases in an orphanage in rural Malawi. In addition, the caregiver uptake of the intervention demonstrated feasibility for future studies.

Prevalence and antimicrobial susceptibility of Salmonella and Shigella species isolated from diarrheic children in Ambo town

BACKGROUND

Diarrhea, particularly of enteric bacterial pathogen, remains a major cause of morbidity and mortality in Ethiopia. Despite the high prevalence of diarrheal disease among under-five children, antibiotic resistance of bacterial pathogens test is not part of routine childcare in the study area. This study aimed to investigate the prevalence and antimicrobial susceptibility status of Salmonella and Shigella species among diarrheic children attending public health institutions in Ambo town, west Showa, Ethiopia.

METHODS

Institutional based, cross-sectional study was carried out from January to July 2014 among 239 diarrheic children below five years of age in Ambo town, Ethiopia. Information about patient demographics, signs, and symptoms was obtained from the parents/guardians of each child using a questionnaire. Stool samples from diarrheic children were collected and processed for isolation of Salmonella and Shigella using conventional microbiology procedures. Suspected Salmonella isolates were confirmed by genus-specific PCR and serotyped using a slide agglutination test. Susceptibility to 10 commonly used antimicrobials was assessed using the Kirby Bauer disc diffusion method.

RESULTS

From the 239 children screened, only nine (3.8%) of them were positive for either Salmonella (n = 3) or Shigella (n = 6) and 19 (7.9%) positive for the intestinal parasite. Three species of Shigella were identified: Shigella flexinari (n = 3), Shigella boydii (n = 2), and Shigella sonnei (n = 1). The three Salmonella isolates were S. chicago, S. caracas, and S. saintpaul. Salmonella and Shigella isolates were resistant to ampicillin (88.9%), followed by tetracycline (66.7%), cotrimoxazole (55.6%), chloramphenicol (44.4%), amoxicillin (33.3%), nalidixic acid (11.1%) and cefotaxime (11.1%). All isolates were sensitive to amikacin, ciprofloxacin, and gentamycin.

CONCLUSION

In this study, either Salmonella or Shigella species were detected only in 3.8% of diarrheic children in Ambo town, suggesting the dominance of other causes of diarrhea in the study area. A further study targeting other causes of diarrhea should be conducted to establish the major causes of childhood diarrhea in the study area.

Epidemiological patterns and antimicrobial resistance of bacterial diarrhea among children in Nairobi City, Kenya

AIM

Determine the prevalence of enteric bacterial pathogens and their antimicrobial resistance among diarrheic children in Nairobi City, Kenya.

BACKGROUND

Regardless of enteric bacterial pathogens being a major cause of gastroenteritis in children, their occurrence and antimicrobial resistance patterns reveals regional spatial and temporal variation.

METHODS

In a cross-sectional study, a total of 374 children below five years presenting with diarrhea at Mbagathi County Hospital were recruited. Stool microbiology test was used to detect enteric bacterial infection. Antimicrobial resistance was determined using the disk diffusion method.

RESULTS

Diarrheagenic E. coli (36.4%) was the leading species followed by Shigella (3.2%), Salmonella (2.4%), Campylobacter (1.6%), Yersinia (1.3%) and Aeromonas (1.1%) species. Escherichia coli pathotyping revealed that 20.9%, 4.0%, 10.2% and 0.5% of the study participants were infected with enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC) and enteroinvasive E. coli (EIEC) pure isolates while the prevalence of mixed pathotype infections was 0.3% for EAEC/EPEC/ETEC and 0.5% for EAEC/ETEC. Shigella sero-grouping revealed that 0.5%, 0.3%, 1.9%, and 0.5% were infected with Shigella boydii, Shigella dysentriae, Shigella flexneri and Shigella sonnei pure isolates. Shigella species and E. coli co-infection was detected in 2.4% of the children, specifically, 1.1% for EAEC/Shigella boydii, 0.5% for EAEC/Shigella dysentriae and 0.3% in each case of EAEC/Shigella sonnei, EPEC/Shigella flexneri and ETEC/Shigella flexneri co-infections. Most of the isolates were resistant to commonly prescribed antibiotics.

CONCLUSION

There was a high prevalence of enteric bacterial pathogens and co-infection alters epidemiological dynamics of bacterial diarrhea in children. Continuous antibiotic resistance surveillance is justified because the pathogens were highly resistant to commonly prescribed antimicrobials.

Incidence and predictors of tuberculosis among HIV-positive adults on antiretroviral therapy at Debre Markos referral hospital, Northwest Ethiopia: a retrospective record review

Background

Tuberculosis is the leading cause of morbidity and mortality among people living with human immunodeficiency virus. Almost one-third of deaths among people living with human immunodeficiency virus are attributed to tuberculosis. Despite this evidence, in Ethiopia, there is a scarcity of information regarding the incidence and predictors of tuberculosis among people living with HIV. Thus, this study assessed the incidence and predictors of tuberculosis among HIV-positive adults on antiretroviral therapy.

Methods

This study was a retrospective record review including 544 HIV-positive adults on antiretroviral therapy at Debre Markos Referral Hospital between January 1, 2012 and December 31, 2017. The study participants were selected using a simple random sampling technique. The data extraction format was adapted from antiretroviral intake and follow-up forms. Cox-proportional hazards regression model was fitted and Cox-Snell residual test was used to assess the goodness of fit. Tuberculosis free survival time was estimated using the Kaplan-Meier survival curve. Both the bi-variable and multivariable Cox-proportional hazard regression models were used to identify predictors of tuberculosis.

Results

In the final analysis, a total of 492 HIV-positive adults were included, of whom, 83 (16.9%) developed tuberculosis at the time of follow-up. This study found that the incidence of tuberculosis was 6.5 (95% CI: 5.2, 8.0) per 100-person-years (PY) of observation. Advanced World Health Organization clinical disease stage (III and IV) (AHR: 2.1, 95% CI: 1.2, 3.2), being ambulatory and bedridden (AHR: 1.8, 95% CI: 1.1, 3.1), baseline opportunistic infections (AHR: 2.8, 95% CI: 1.7, 4.4), low hemoglobin level (AHR: 3.5, 95% CI: 2.1, 5.8), and not taking Isonized Preventive Therapy (AHR: 3.9, 95% CI: 1.9, 7.6) were found to be the predictors of tuberculosis.

Conclusion

The study found that there was a high rate of tuberculosis occurrence as compared to previous studies. Baseline opportunistic infections, being ambulatory and bedridden, advanced disease stage, low hemoglobin level, and not taking Isonized Preventive Therapy were found to be the predictors of tuberculosis. Therefore, early detection and treatment of opportunistic infections like tuberculosis should get a special attention.

Prevalence and determinants of diarrhea among under-five children in Ethiopia: A systematic review and meta-analysis

BACKGROUND

Despite remarkable progress in the reduction of under-five mortality, childhood diarrhea is still the leading cause of mortality and morbidity in this highly susceptible and vulnerable population. In Ethiopia, study findings regarding prevalence and determinants of diarrhea amongst under-five children have been inconsistent. Therefore, this systematic review and meta-analysis estimates the pooled prevalence of diarrhea and its determinants among under-five children in Ethiopia.

METHODS

International databases, including PubMed, Web of Science, EMBASE, CINAHL, Google Scholar, Science Direct, and the Cochrane Library, were systematically searched. All identified observational studies reporting the prevalence and determinants of diarrhea among under-five children in Ethiopia were included. Two authors independently extracted all necessary data using a standardized data extraction format. STATA Version 13 statistical software was used. The Cochrane Q test statistics and I2 test were used to assess the heterogeneity of the studies. A random effects model was computed to estimate the pooled prevalence of diarrhea. Moreover, the associations between determinant factors and childhood diarrhea were examined using the random effect model.

RESULTS

After reviewing of 535 studies, 31studies fulfilled the inclusion criteria and were included in the meta-analysis. The findings from the 31 studies revealed that the pooled prevalence of diarrhea among under-five children in Ethiopia was 22% (95%CI: 19, 25%). Subgroup analysis of this study revealed that the highest prevalence was observed in Afar region (27%), followed by Somali and Dire Dawa regions (26%), then Addis Abeba (24%). Lack of maternal education (OR: 2.5, 95% CI: 1.3, 2.1), lack of availability of latrine (OR: 2.0, 95%CI: 1.3, 3.2), urban residence (OR: 1.9, 95%CI: 1.2, 3.0), and maternal hand washing (OR: 2.2, 95%CI: 2.0, 2.6) were significantly associated with childhood diarrhea.

CONCLUSION

In this study, diarrhea among under-five children in Ethiopia was significantly high. Lack of maternal education, lack of availability of latrine, urban residence, and lack of maternal hand washing were significantly associated with childhood diarrhea.

Diarrhea Prevalence and Sociodemographic Factors among Under-Five Children in Rural Areas of North Gondar Zone, Northwest Ethiopia

Background

Diarrheal disease remains one of the principal causes of morbidity and mortality in infants and children in developing countries, including Ethiopia. Risk factors for diarrhea vary by settings and have important implications for developing intervention strategies to reduce the burden of the disease. Thus, the aim of this study was to assess diarrhea prevalence and sociodemographic factors among under-five children in rural areas of North Gondar Zone.

Methods

A community-based cross-sectional study was conducted from April to June 2016 among 736 randomly selected households with one child under five years old. A structured questionnaire was used for collecting information on sociodemographic characteristics and diarrheal occurrence. Data was analyzed using SPSS version 20. The bivariate and multivariable logistic regression analysis were used to determine the association between risk factors and diarrheal occurrence, and a p value < 0.05 was taken as statistically significant.

Results

A total of 736 under-five children and their respondents were enrolled during the study period. Almost all respondents were biological mothers 96.4% (709/736), married 94.2% (693/736), and house wives 86% (632/736). The overall prevalence of diarrheal disease among under-five children was 22.1% (163/743). Of these, children with age group of less than one year old, 7.7 % (57/736), were commonly infected with diarrheal diseases. Children less than or equal to one year [AOR=1.82, 95% CI= (1.39, 4.63)], guardians [AOR=4.37, 95% CI= (1.73, 11.1)], and children with no breast feeding practice [AOR=3.13, 95% CI= (1.62, 6.03)] were the major risk factors for the occurrence of diarrhea.

Conclusion

Childhood diarrhea remains an important health concern in the study area. Occurrence of diarrhea was statistically associated with child age less than or equal to one year, educational status of mother/guardians, and breast feeding. To minimize the magnitude childhood diarrhea, various designing and implementing strategies, such as health education, child care, breast feeding, and weaning practice, integrated with the existing national health extension are quite essential.

Antimicrobial susceptibility pattern, and associated factors of Salmonella and Shigella infections among under five children in Arba Minch, South Ethiopia

Background

Diarrheal diseases continue to be the major cause of morbidity and mortality among children under 5 years. Salmonella and Shigella specious are the major enteric pathogen causing diarrhea among children worldwide. Examination of stool sample is the most sensitive method to diagnose diarrheal disease in children. This study aimed to determining the prevalence, antimicrobial susceptibility pattern and associated factor of Salmonella and Shigella infection among under five children.

Methods

A cross sectional study was conducted on under 5 years children attending Arba Minch town. Pre-tested and structured questionnaire was used for collecting data about socio-demographic characteristics and associated factors. Stool sample was used to isolate and identified the pathogen. Antimicrobial susceptibility test was performed for isolated Salmonella and Shigella specious. A logistic regression analysis was used to see the association between different variables and outcome variable. Odds ratio with 95% CI was computed to determine the presence and strength of the association.

Results

A total of 167 under five children were included in the study. About 57% of participants were males with the mean age of 32 months. The overall prevalence of Salmonella and Shigella species infection was 17.45% with 12.6% Salmonella species. The isolates were resistant to common antibiotics such as Amoxicillin, Erythromycin, Chloramphenicol, Clindamycin, Norfloxacin, Ciprofloxacin, Cotrimoxazole, and Gentamycin. Urban resident [AOR = 7.11; 95% CI (2.3, 22.2)], month income < 1000 Ethiopian birr [AOR = 6.5; 95% CI (2.0, 21.4)], absence of waste disposal system [AOR = 3.3; 95% CI (1.2, 9.3)], poor hand washing habit [AOR = 6.0; 95% CI (2.0, 18.2)], untrimmed finger nail [AOR = 3.7; 95% CI (1.4, 10.6)], and use of napkin [AOR = 3.2; 95% CI (1.1, 9.3)] had significant association with Salmonella and Shigella infection.

Conclusion

Salmonella and Shigella species infections were higher as compared the national prevalence. This study also revealed that the enteric infection were significantly associated with finger nail status, residence, hand washing practice, month income of parents, usage of napkin after toilet, and absence of waste disposal system. Therefore, working on identified associated factors and regular drug susceptibility test is mandatory to reduce the problem.

Etiology and pathogenicity of bacterial isolates: a cross sectional study among diarrheal children below five years in central regions of Kenya

INTRODUCTION

Bacterial agents are among pathogens implicated to cause diarrhea in children resulting to huge mortality and morbidities. Bacterial etiologies causing diarrhea in children below five years are rarely investigated in Central Kenya, which would otherwise guide prescription and target health education.

METHODS

A cross-sectional study approach was applied on 163 randomly selected stool samples from children below five years who presented with diarrhea in Murang`a and Muriranja`s hospitals. The objective was to determine the bacterial agents of diarrhea. Enteric bacterial pathogens were cultured using appropriate media and identified. Statistical analyses were performed using STATA v.13. Chi-square or Fisher exact-test were used to check for evidence of relationship whenever applicable.

RESULTS

There were nearly equal distributions in gender 86 (52.8%) female vs. 77 (47.2%) male, majority (35.6%) aged between 0-12 months. Bacterial isolates were highly diverse in female than the male, children aged 49-60 months and least among those aged 0-12 months. A total of 188 bacterial isolates belonging to 11 genera were recovered. The predominant bacteria was nonpathogenic Escherichia coli 85 (45.2%), while 13 (6.9%) Escherichia coli were positive for virulence genes, including 8 (4.3%) positive for LT and STp Shiga-like or Enterotoxigenic Escherichia coli, 3 (1.6%) positive for eae and bfpA Enteropathogenic Escherichia coli and 2 (1.1%) positive for Enteroaggregative Escherichia coli gene. Others included: Salmonella 21 (11.2%), Pseudomonas 14 (7.4%), Shigella 14 (7.4%), Klebsiella 12 (6.4%), Aeromonas 8 (4.3%), Enterobacter 7 (3.7%), Proteus 8 (4.3%), Citrobactor 3 (1.6%), Yersinia 2 (1.1%) and Vibrio 1 (0.5%).

CONCLUSION

Salmonella was the major bacterial isolate and majority of the bacteria were statistically significant cause of diarrhea (p=0.001).

Influence of Water, Sanitation, and Hygiene Practices on Common Infections among Under-Five Children in Longido and Monduli Districts of Arusha, Tanzania

The study aimed at assessing water, sanitation, and hygiene practices and their influence on infectious diseases among under-five children in semipastoral communities of Arusha. The study was cross-sectional in design. Prevalence of infectious diseases among under-five children was derived from patients' attendance register. Mothers randomly sampled from households were interviewed using questionnaire. Information regarding child morbidity and sociodemographic and WASH characteristics was gathered. Hospital data revealed that 2/3 of under-five patients visited the hospitals annually were suffering from infectious diseases. Mean percentage of diarrhea prevalence for years 2013–2015 in Longido was higher than the mean of the respective years prevalence in Monduli (p = 0.02). Households' survey showed that 15.5% of under-five children were suffering from diarrhea. Children who consumed foods kept in kibuyu (p < 0.001) or used unboiled cows' milk (p = 0.01) or were drinking surface water (p = 0.04) or born to uneducated mothers (p = 0.01) had increased risk of developing diarrhea compared to their counterparts. Storing complementary foods in kibuyu was strongly associated with diarrhea among under-five children. To address the problem, communities under study need to be motivated through health education on food hygiene, proper handling of food storage containers, and domestic water treatment at the household level.

Identification of different Escherichia coli pathotypes in north and north-west provinces of Iran

BACKGROUND AND OBJECTIVES

Diarrhea is one of the most prevalent diseases in the world, specially in developing countries. One of the most important causative agents of bacterial diarrhea is diarrheagenic Escherichia coli (DEC) which causes gastroenteritis and this group involving enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterohemoragic E. coli (EHEC), enteroinvasive E. coli (EIEC), diffusely adherence E. coli (DAEC). The aim of this study was to identify different E. coli pathotypes in north and north-west of Iran, among the clinical isolates.

MATERIALS AND METHODS

In this study for identification of E. coli, 170 fecal samples were cultured on MacConkey agar and identified by biochemical tests. Samples with E. coli characteristics were selected (145 samples) and their genomes were purified by phenol-chloroform method. After extraction of genomes, lt and sta genes identified by PCR for ETEC, eae gene for atypical and eae and bfp for typical EPEC, AA region for EAEC, stx₁ and stx₂ and eae genes for EHEC (stx₁ or stx₂ or both for STEC) and invE for EIEC.

RESULTS

Finally 10 samples identified as ETEC (%5.88), 18 (%10.58) EPEC, 6 (%3.52) EHEC and 12 (7.05%) samples were STEC. None of the samples were positive for EAEC and EIEC.

CONCLUSION

The results obtained in this study showed that ETEC, EPEC, EHEC and STEC are prevalent bacterial agents in north and north-west of Iran. Complementary studies to identify these pathotypes in other seasons can help to adopt necessary policies against outbreaks in Iran.

Escherichia coli pathotypes and Shigella sero-groups in diarrheic children in Nairobi city, Kenya

AIM

In the present study, we investigated the prevalence of E. coli pathotypes and Shigella sero-groups and their antimicrobial profiles among diarrheic children in Nairobi city, Kenya.

BACKGROUND

Although diarrheagenic E. coli pathotypes and Shigella sero-groups are leading causes of diarrhea in children under five years in developing countries, their distribution and antimicrobial resistance vary from place to place and over time in a given region.

METHODS

In a cross-sectional study, we enrolled diarrheic children (n=354) under five years seeking treatment at Mbagathi Hospital, Nairobi city, Kenya,. Stool samples were collected from all children for bacterial culture. Bacterial isolation and identification was performed by conventional microbiological methods. Polymerase chain amplification was used to detect aspU, aggR, andpcvd432 for EAEC, est and elt for ETEC, eae for EPEC, stx for EHEC, and ipaH for EIEC and Shigella species. Antimicrobial profile was determined by disk diffusion method.

RESULTS

The prevalence of EAEC, ETEC, EPEC (eae), EIEC (ipaH) was 21.2%, 10.5%, 4.5%, and 0.6%, respectively, while that of mixed infection was 0.6%for ETEC/EAEC and 0.3%for EAEC/EPEC/ETEC. No EHEC strain was isolated. Pathogenetic analysis for EAEC showed that5.9% carried aspU,8.2% possessed both aspU and aggR and 7.1% had a combination of aspU, aggR andpcvd432 while that of ETEC was 2.3% for elt, 6.5% for both elt and est and 1.7% for est. The combination of aspU with aggR, elt and est, and pcvd432 with aggR, aspU and est was 0.3% for each case of ETEC/EAEC mixed infection. The aspU gene co-existed with aggR, pcvd432, eae and elt in the EAEC/EPEC/ETEC mixed infection. The prevalence of S. boydii, S. dysenteriae, S. flexneriand,S. sonnei was 0.8%, 0.6%, 1.7%, and 0.8%, respectively. No E. coli pathotype and shigella co-infection was detected. In addition, both E. coli pathotypes and Shigella species were resistant to ampicillin, trimethoprim/sulfamethoxazole, streptomycin, chloramphenicol and tetracycline while gentamycin and kanamycin resistance occurred in diarrheagenic E. coli.

CONCLUSION

E. coli pathotypes and Shigella sero-groups harboring virulent genes are important causes of diarrhea in children in Kenya. The increasing spectrum of antibiotic resistance in diarrheagenic E. coli and Shigella species necessitates the development of antimicrobial stewardship education-programs to influence prescribing behavior as well as optimizing the use of effective antimicrobials in Kenya.

Diarrheagenic Escherichia coli pathotypes frequency in Khuzestan province of Iran

BACKGROUND AND OBJECTIVES

Diarrheagenic Escherichia coli (DEC) is an emerging agent among pathogens that causes diarrhea. Studies showed that diarrheagenic E. coli such as enterohaemorrhagic E. coli (EHEC), enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC), enterotoxigenic E. coli (ETEC), diffusely adhering E. coli (DAEC) and shiga toxin producing E. coli (STEC) strains are among the most frequent causative agents in acute diarrhea. The aim of this study was to determine the frequency of DEC pathotypes in Khuzestan province.

MATERIALS AND METHODS

Stool samples were collected from patients with diarrhea in Khuzestan province of Iran. E. coli strains were isolated using conventional culture and standard biochemical tests. The polymerase chain reaction (PCR) technique was used to detect presence of virulence genes, i.e; eae, stx1 and stx2 for EHEC, bfp and eae for EPEC, LT and ST for ETEC, AA for EAEC, invE for EIEC, stx1 and stx2 for STEC.

RESULTS

Altogether, 200 stool samples were obtained from patients, of which 158 (79%) were positive for E. coli. DEC was identified in 127 (63%) of stool samples, which frequency of each pathotypes were as follows: atypical EPEC 49 (39%), typical EPEC 1 (0.7%), STEC 50 (39.3%), ETEC 21 (16.3%), EAEC 5 (4.0%) and EIEC 1 (0.7%). Most frequent etiological agents of diarrhea in Khuzestan province of Iran were STEC and EPEC.

CONCLUSION

Our findings showed DEC had been agent of diarrhea in Khuzestan. This finding provides evidence that effort should be made to estimate the burden of infection by the etiological agent for better medical approach and should raise notification about antibiotic resistance among bacterial infection.

Failure of Syndrome-Based Diarrhea Management Guidelines to Detect Shigella Infections in Kenyan Children

BACKGROUND

Shigella is a leading cause of childhood diarrhea mortality in sub-Saharan Africa. Current World Health Organization guidelines recommend antibiotics for children in non cholera-endemic areas only in the presence of dysentery, a proxy for suspected Shigella infection.

METHODS

To assess the sensitivity and specificity of the syndromic diagnosis of Shigella-associated diarrhea, we enrolled children aged 6 months to 5 years presenting to 1 of 3 Western Kenya hospitals between November 2011 and July 2014 with acute diarrhea. Stool samples were tested using standard methods for bacterial culture and multiplex polymerase chain reaction for pathogenic Escherichia coli. Stepwise multivariable logit models identified factors to increase the sensitivity of syndromic diagnosis.

RESULTS

Among 1360 enrolled children, median age was 21 months (interquartile range, 11-37), 3.4% were infected with human immunodeficiency virus, and 16.5% were stunted (height-for-age z-score less than -2). Shigella was identified in 63 children (4.6%), with the most common species being Shigella sonnei (53.8%) and Shigella flexneri (40.4%). Dysentery correctly classified 7 of 63 Shigella cases (sensitivity, 11.1%). Seventy-eight of 1297 children without Shigella had dysentery (specificity, 94.0%). The combination of fecal mucous, age over 23 months, and absence of excessive vomiting identified more children with Shigella-infection (sensitivity, 39.7%) but also indicated antibiotics in more children without microbiologically confirmed Shigella (specificity, 82.7%).

CONCLUSIONS

Reliance on dysentery as a proxy for Shigella results in the majority of Shigella-infected children not being identified for antibiotics. Field-ready rapid diagnostics or updated evidence-based algorithms are urgently needed to identify children with diarrhea most likely to benefit from antibiotic therapy.

Diarrhoea morbidity patterns in Central Region of Ghana

Introduction

Diarrhoea diseases remain a major public health threat with nearly 1.7 billion cases annually worldwide occurring in all age groups. In Ghana diarrhoea kills about 14,000 children under five years annually. We therefore analysed data to determine the morbidity pattern of diarrhoea diseases in the Central Region of Ghana.

Methods

Health facility morbidity data was reviewed from 2008-2012. Monthly data on diarrhoeal diseases were extracted from District Health Information Management System database by sex, age group and districts. Data for bloody diarrhoea were extracted from monthly surveillance report forms. Data was analysed descriptively and expressed as frequencies and proportionate morbidity rates (pmr). Aberrations were determined using C2 threshold.

Results

The total cases of all morbidity from 2008 to 2012 were 7,642,431. Diarrhoea diseases formed 4% (306854/7642431) of total morbidity. Children under one year (pmr= 8.4%) and males (pmr= 4.4%) were the most affected. Bloody diarrhea formed 2.2% (6835/306854) of diarrhoea cases with 0.7 %(45/6835) laboratory confirmed. Diarrhoea cases peaked from January to March throughout the study period with highest frequency 9.3% (28511/306854) in June. The mean monthly distribution of diarrhoea cases was 25571.17±1389.91. Poorest districts had significantly lower odds of getting bloody diarrhoea than non-poorest districts OR = 0.73 (95%CI = 0.70-0.77).

Conclusion

Diarrhoea characterized 4% of total morbidity presenting at health facilities in the region from 2008 to 2012. The diarrhoea morbidity rate decreased with increased age. Diarrhoea was higher among non poorest districts. The rate was highest in the month of June over the five year period. Bloody diarrhoea cases were mostly untested. We recommended that stool samples should be taken for laboratory testing for bloody diarrhoea cases.

Risk factors of diarrhea in children under 5 years in Al-Mukalla, Yemen

Objectives:

To assess the risk factors associated with diarrhea among children below 5-years-old in Mukalla, Yemen, and compare with other studies.

Methods:

We conducted a case-control study on 200 children (100 cases and 100 controls) who attended the Maternity and Child Hospital, outpatient-clinics, and the Primary Health Care Centers in Al-Mukalla, Hadhramout, Yemen between February and April 2013.

Results:

We found that the significant risk factors associated with diarrhea were crowded housing (odds ratio [OR] 2.02; p=0.02; confidence interval [CI] 1.03-4.01), incomplete vaccination of the child (OR=2.02; p=0.027; CI: 1.08-3.8), and recurrent diarrheal illness during the last 3 months (OR=6.61; p=0.001; CI: 3.41-12.90).

Conclusion:

Diarrheal diseases are strongly associated with incomplete vaccination, recurrent diarrheal disease, and crowded housing.

Enteric bacterial pathogens in children with diarrhea in Niger: diversity and antimicrobial resistance

Background

Although rotavirus is the leading cause of severe diarrhea among children in sub-Saharan Africa, better knowledge of circulating enteric pathogenic bacteria and their antimicrobial resistance is crucial for prevention and treatment strategies.

Methodology/Principal Findings

As a part of rotavirus gastroenteritis surveillance in Maradi, Niger, we performed stool culture on a sub-population of children under 5 with moderate-to-severe diarrhea between April 2010 and March 2012. Campylobacter, Shigella and Salmonella were sought with conventional culture and biochemical methods. Shigella and Salmonella were serotyped by slide agglutination. Enteropathogenic Escherichia coli (EPEC) were screened by slide agglutination with EPEC O-typing antisera and confirmed by detection of virulence genes. Antimicrobial susceptibility was determined by disk diffusion. We enrolled 4020 children, including 230 with bloody diarrhea. At least one pathogenic bacterium was found in 28.0% of children with watery diarrhea and 42.2% with bloody diarrhea. Mixed infections were found in 10.3% of children. EPEC, Salmonella and Campylobacter spp. were similarly frequent in children with watery diarrhea (11.1%, 9.2% and 11.4% respectively) and Shigella spp. were the most frequent among children with bloody diarrhea (22.1%). The most frequent Shigella serogroup was S. flexneri (69/122, 56.5%). The most frequent Salmonella serotypes were Typhimurimum (71/355, 20.0%), Enteritidis (56/355, 15.8%) and Corvallis (46/355, 13.0%). The majority of putative EPEC isolates was confirmed to be EPEC (90/111, 81.1%). More than half of all Enterobacteriaceae were resistant to amoxicillin and co-trimoxazole. Around 13% (46/360) Salmonella exhibited an extended-spectrum beta-lactamase phenotype.

Conclusions

This study provides updated information on enteric bacteria diversity and antibiotic resistance in the Sahel region, where such data are scarce. Whether they are or not the causative agent of diarrhea, bacterial infections and their antibiotic resistance profiles should be closely monitored in countries like Niger where childhood malnutrition pre-disposes to severe and invasive infections.

Update on molecular epidemiology of Shigella infection

PURPOSE OF REVIEW

Shigella spp. are important etiologic agents of diarrhea worldwide. This review summarizes the recent findings on the epidemiology, diagnosis, virulence genes, and pathobiology of Shigella infection.

RECENT FINDINGS

Shigella flexneri and Shigella sonnei have been identified as the main serogroups circulating in developing and developed countries, respectively. However, a shift in the dominant species from S. flexneri to S. sonnei has been observed in countries that have experienced recent improvements in socioeconomic conditions. Despite the increasing usage of molecular methods in the diagnosis and virulence characterization of Shigella strains, researchers have been unsuccessful in finding a specific target gene for this bacillus. New research has demonstrated the role of proteins whose expressions are temperature-regulated, as well as genes involved in the processes of adhesion, invasion, dissemination, and inflammation, aiding in the clarification of the complex pathobiology of shigellosis.

SUMMARY

Knowledge about the epidemiologic profile of circulating serogroups of Shigella and an understanding of its pathobiology as well as of the virulence genes is important for the development of preventive measures and interventions to reduce the worldwide spread of shigellosis.