On 17 October 2023, the County of San Diego (CoSD), California's Epidemiology and Immunization Services Branch received reports of eight salmonellosis patients with illness onsets beginning in September 2023. CoSD disease investigators identified common exposure to Farm A-produced unpasteurized dairy products and performed epidemiologic and environmental investigations. Isolates were submitted for whole-genome sequencing. Cases were defined as persons with Salmonella infection with an isolation date on or after 15 September 2023. Twenty-five cases, including 23 confirmed and two probable, were identified among county residents, with 19 (76%) reporting exposure to Farm A unpasteurized dairy products. Median patient age was 12 years (range: 1-47 years). Three children (12%) were hospitalized. Environmental samples of unpasteurized milk collected from Farm A tested positive for S. Typhimurium, matching the outbreak strain by WGS. After Salmonella identification, CoSD released early advisories warning of Farm A-associated risks, likely preventing additional infections.

BackgroundAutomated access to timely and accurate clinical information is essential for infection and sepsis management, public health surveillance, and emergency response. However, notifiable disease reporting is largely dependent on electronic laboratory data transfer and follow-up case interviews that are subject to delayed reporting and manual chart extraction that hinder timely case investigation and interfacility communication.MethodsWe investigated whether an artificial intelligence (AI)-based abstraction, combining interoperable electronic health record data with locally hosted large language models (LLM) in a secure cloud environment, could automatically generate high quality public health reporting forms for reportable public health diseases. Using two case studies (multidrug-resistant organism (MDRO) surveillance and dengue fever case identification and reporting), we integrated structured data and unstructured data from Fast Healthcare Interoperability Resources (FHIR) to generate automated case-report forms.ResultsMDRO transfer forms were reviewed by subject matter experts (board-certified infectious disease physicians) who reported no major errors in fidelity. Dengue fever case investigation forms were validated by County of San Diego Public Health Services staff confirming LLM had captured essential information with high concordance as well as additional important context that was not present in the submitted human-completed forms.ConclusionsThese findings demonstrate the feasibility of interoperable, AI-based workflows for case-report generation using an interoperable architecture. Further, these findings highlight opportunities to automate and scale syndromic surveillance efficiently, accelerating clinical and public health response, while supporting reliable interfacility communication.

Hepatitis A virus (HAV) remains a significant public health concern in the United States. Because infected individuals shed virus through stool, HAV can be detected in wastewater. Shedding occurs prior to the onset of symptoms that lead to clinical diagnosis, highlighting the potential of wastewater as an early case detection tool. This analysis aims to quantify key diagnostic metrics of wastewater surveillance for detecting HAV cases, which have not been previously defined. Utilizing wastewater data from the Point Loma Wastewater Treatment Facility in San Diego County, which serves around 2.2 million people, we assessed the sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of wastewater HAV signals (positive/negative) in identifying shedding cases over a 308-day period. The number of people shedding virus on a given day was estimated through confirmed cases and presumed shedding intervals (2 weeks before and 1 week after symptom onset) and compared to wastewater signals. The sensitivity in detecting at least one shedding case on a given day using observed wastewater signals was 48.1%. Reclassifying the wastewater signal using simple data aggregations yielded sensitivities from 67.3% to 84.6%. Sensitivity increased as more individuals were shedding virus. The highest PPV (52.2%) and NPV (74.2%) were observed when a 5-sample trimmed centered average was used to reclassify the wastewater signal, indicating the utility of this preprocessing method. Conditional on clinical case detection and shedding assumptions, our study demonstrates that wastewater is a promising tool, providing signals that can inform public health surveillance.

OBJECTIVE:Describe health outcomes among workers affected by the Tijuana River Valley (TRV) sewage crisis. METHODS:In October-November 2024, a cross-sectional online survey was administered to individuals who worked in areas affected by the TRV sewage crisis as part of an Assessment of Chemical Exposures. RESULTS:Among 443 workers, 110 (25%) reported direct contact with contaminated Tijuana River or beach water. 55% of workers reported exposure to severe odor. Nearly two-thirds experienced physical symptoms attributed to the crisis, and one-third missed work due to symptoms. Direct water contact was linked to higher prevalence of physical and mental health symptoms and absenteeism. Those reporting work-related direct water contact were largely outdoor workers. CONCLUSIONS:TRV workers have experienced health impacts due to the ongoing sewage crisis. Findings may help inform public health response and resource needs.

The Tijuana River Valley along the US-Mexico border faces a severe environmental and public health crisis from contamination of the Tijuana River with untreated sewage, urban runoff, and industrial waste, leading to water and air exposure concerns. The County of San Diego Health and Human Services Agency (CoSD HHSA) and the Centers for Disease Control and Prevention (CDC) conducted 189 household-level surveys to assess experiences with the crisis and address concerns. Survey results revealed that ~96% of households were concerned about the crisis. Top needs included requests for action (64.3%) and air (38.2%) and water (27.1%) quality improvement. Subsequently, CoSD HHSA developed data-driven outreach programs and resources (e.g., provision of air filters), enhanced messaging (e.g., providing educational materials, promoting behavioral health hotlines) related to the crisis to address household concerns, and shared the results with other agencies (e.g., the water board) to promote further action and safety messaging.

Unpasteurized (raw) milk has been linked to foodborne illness outbreaks caused by Escherichia coli bacteria and certain species of Brucella, Campylobacter, Cryptosporidium, and Salmonella. In October 2023, the County of San Diego Health and Human Services Agency notified the California Department of Public Health (CDPH) of eight cases of salmonellosis in persons who reported consuming brand A raw milk, produced exclusively by dairy farm A. A total of 171 outbreak-associated Salmonella Typhimurium cases were identified through review of standardized salmonellosis case report forms and a search of PulseNet, CDC's national molecular subtyping network for enteric disease surveillance, followed by administration of a dairy-focused supplementary questionnaire. Most cases (98%) were identified in California; one case each was identified in four other states. Among the 171 cases, 120 (70%) cases and 18 (82%) of the cases requiring hospitalization were among children and adolescents aged <18 years. Among 159 patients confirmed to be infected with the outbreak strain, 55 (70%) of those with exposure data consumed brand A raw milk or heavy cream. Four of 40 samples collected from dairy farm A, retail stores, and patients' homes, including raw milk and raw milk cheese aged for 60 days, tested positive for the outbreak strain of S. Typhimurium by whole-genome sequencing. Dairy farm A voluntarily recalled raw milk and raw heavy cream 1 week after the initial outbreak identification. Commercially distributed raw dairy products have the potential to cause large and widespread infectious disease outbreaks. Public health authorities should continue to raise awareness of the risks associated with consuming raw dairy products, especially by persons at increased risk for severe disease from enteric pathogens, including children.

Rocky mountain spotted fever (RMSF) causes significant illness and death in children. Although historically rare in California, USA, RMSF is endemic in areas of northern Mexico that border California. We describe 7 children with RMSF who were hospitalized at a tertiary pediatric referral center in California during 2017-2023. Five children had recent travel to Mexico with presumptive exposure, but 2 children did not report any travel outside of California. In all 7 patients, Rickettsia rickettsii DNA was detected by plasma microbial cell-free next-generation sequencing, which may be a useful diagnostic modality for RMSF, especially early in the course of illness, when standard diagnostic tests for RMSF are of limited sensitivity. A high index of suspicion and awareness of local epidemiologic trends remain most critical to recognizing the clinical syndrome of RMSF and initiating appropriate antimicrobial therapy in a timely fashion.

Enterovirus infections in neonates can result in high morbidity and mortality.In 2023, a cluster of neonatal enterovirus cases associated with Coxsackie B4 and B5 occurred in San Diego, California.

During October 2021, the County of San Diego Health and Human Services Agency identified five cases of shigellosis among persons experiencing homelessness (PEH). We conducted an outbreak investigation and developed interventions to respond to shigellosis outbreaks among PEH. Confirmed cases occurred among PEH with stool-cultured Shigella sonnei; probable cases were among PEH with Shigella-positive culture-independent diagnostic testing. Patients were interviewed to determine infectious sources and risk factors. Fifty-three patients were identified (47 confirmed, 6 probable); 34 (64%) were hospitalised. None died. No point source was identified. Patients reported inadequate access to clean water and sanitation facilities, including public restrooms closed because of the COVID-19 pandemic. After implementing interventions, including handwashing stations, more frequent public restroom cleaning, sanitation kit distribution, and isolation housing for ill persons, S. sonnei cases decreased to preoutbreak frequencies. Improving public sanitation access was associated with decreased cases and should be considered to prevent outbreaks among PEH.

BACKGROUND:COVID-19 vaccination reduces SARS-CoV-2 infection and transmission. However, evidence is emerging on the degree of protection across variants and in high-transmission settings. To better understand the protection afforded by vaccination specifically in a high-transmission setting, we examined household transmission of SARS-CoV-2 during a period of high community incidence with predominant SARS-CoV-2 B.1.1.7 (Alpha) variant, among vaccinated and unvaccinated contacts. METHODS:We conducted a household transmission investigation in San Diego County, California, and Denver, Colorado, during January-April 2021. Households were enrolled if they had at least one person with documented SARS-CoV-2 infection. We collected nasopharyngeal swabs, blood, demographic information, and vaccination history from all consenting household members. We compared infection risks (IRs), RT-PCR cycle threshold values, SARS-CoV-2 culture results, and antibody statuses among vaccinated and unvaccinated household contacts. RESULTS:We enrolled 493 individuals from 138 households. The SARS-CoV-2 variant was identified from 121/138 households (88%). The most common variants were Alpha (75/121, 62%) and Epsilon (19/121, 16%). There were no households with discordant lineages among household members. One fully vaccinated secondary case was symptomatic (13%); the other 5 were asymptomatic (87%). Among unvaccinated secondary cases, 105/108 (97%) were symptomatic. Among 127 households with a single primary case, the IR for household contacts was 45% (146/322; 95% Confidence Interval [CI] 40-51%). The observed IR was higher in unvaccinated (130/257, 49%, 95% CI 45-57%) than fully vaccinated contacts (6/26, 23%, 95% CI 11-42%). A lower proportion of households with a fully vaccinated primary case had secondary cases (1/5, 20%) than households with an unvaccinated primary case (66/108, 62%). CONCLUSIONS:Although SARS-CoV-2 infections in vaccinated household contacts were reported in this high transmission setting, full vaccination protected against SARS-CoV-2 infection. These findings further support the protective effect of COVID-19 vaccination and highlight the need for ongoing vaccination among eligible persons.

IMPORTANCE As self-collected home antigen tests become widely available, a better understanding of their performance during the course of SARS-CoV-2 infection is needed. OBJECTIVE To evaluate the diagnostic performance of home antigen tests compared with reverse transcription-polymerase chain reaction (RT-PCR) and viral culture by days from illness onset, as well as user acceptability. DESIGN, SETTING. AND PARTICIPANTS This prospective cohort study was conducted from January to May 2021 in San Diego County, California, and metropolitan Denver, Colorado. The convenience sample included adults and children with RT-PCR-confirmed infection who used self collected home antigen tests for 15 days and underwent at least 1 nasopharyngeal swab for RT-PCR, viral culture, and sequencing. EXPOSURES SARS-CoV-2 infection. MAIN OUTCOMES AND MEASURES The primary outcome was the daily sensitivity of home antigen tests to detect RT-PCR-confirmed cases. Secondary outcomes included the daily percentage of antigen test, RT-PCR, and viral culture results that were positive, and antigen test sensitivity compared with same-day RT-PCR and cultures, Antigen test use errors and acceptability were assessed for a subset of participants. Results This study enrolled 225 persons with RT-PCR-confirmed infection (median [range] age, 29 [1-83] years; 117 female participants [52%]; 10 [4%] Asian, 6 [3%] Black or African American, 50 [22%] Hispanic or Latino, 3 [1%] Native Hawaiian or Other Pacific Islander, 145 [64%] White, and 11 [5%] multiracial individuals) who completed 3044 antigen tests and 642 nasopharyngeal swabs. Antigen test sensitivity was 50% (95% CI, 45%-55%) during the infectious period, 64% (95% CI, 56%-70%) compared with same-day RT-PCR, and 84% (95% CI, 75%-90%) compared with same-day cultures. Antigen test sensitivity peaked 4 days after illness onset at 77% (95% CI, 69%-83%). Antigen test sensitivity improved with a second antigen test 1 to 2 days later, particularly early in the infection. Six days after illness onset, antigen test result positivity was 61% (95% CI, 53%-68%). Almost all (216 [96%]) surveyed individuals reported that they would be more likely to get tested for SARS-CoV-2 infection if home antigen tests were available over the counter. Conclusions and Relevance The results of this cohort study of home antigen tests suggest that sensitivity for SARS-CoV-2 was moderate compared with RT-PCR and high compared with viral culture. The results also suggest that symptomatic individuals with an initial negative home antigen test result for SARS-CoV-2 infection should test again 1 to 2 days later because test sensitivity peaked several days after illness onset and improved with repeated testing.

In an investigation involving 127 households with 322 household contacts, household secondary infection risks were similar for persons with Alpha and non-Alpha lineages of SARS-CoV-2. Avoiding close contact within households may reduce SARS-CoV-2 transmission for all lineages among household members. Background In Spring 2021, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.7 (Alpha) became the predominant variant in the United States. Research suggests that Alpha has increased transmissibility compared with non-Alpha lineages. We estimated household secondary infection risk (SIR), assessed characteristics associated with transmission, and compared symptoms of persons with Alpha and non-Alpha infections. Methods We followed households with SARS-CoV-2 infection for 2 weeks in San Diego County and metropolitan Denver, January to April 2021. We collected epidemiologic information and biospecimens for serology, reverse transcription-polymerase chain reaction (RT-PCR), and whole-genome sequencing. We stratified SIR and symptoms by lineage and identified characteristics associated with transmission using generalized estimating equations. Results We investigated 127 households with 322 household contacts; 72 households (56.7%) had member(s) with secondary infections. SIRs were not significantly higher for Alpha (61.0% [95% confidence interval, 52.4-69.0%]) than non-Alpha (55.6% [44.7-65.9%], P = .49). In households with Alpha, persons who identified as Asian or Hispanic/Latino had significantly higher SIRs than those who identified as White (P = .01 and .03, respectively). Close contact (eg, kissing, hugging) with primary cases was associated with increased transmission for all lineages. Persons with Alpha infection were more likely to report constitutional symptoms than persons with non-Alpha (86.9% vs 76.8%, P = .05). Conclusions Household SIRs were similar for Alpha and non-Alpha. Comparable SIRs may be due to saturation of transmission risk in households due to extensive close contact, or true lack of difference in transmission rates. Avoiding close contact within households may reduce SARS-CoV-2 transmission for all lineages among household members.

Objective To assess the household secondary infection risk (SIR) of B.1.1.7 (Alpha) and non-Alpha lineages of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children. Study design During January to April 2021, we prospectively followed households with a SARS-CoV-2 infection. We collected questionnaires, serial nasopharyngeal swabs for reverse transcription polymerase chain reaction testing and whole genome sequencing, and serial blood samples for serology testing. We calculated SIRs by primary case age (pediatric vs adult), household contact age, and viral lineage. We evaluated risk factors associated with transmission and described symptom profiles among children. Results Among 36 households with pediatric primary cases, 21 (58%) had secondary infections. Among 91 households with adult primary cases, 51 (56%) had secondary infections. SIRs among pediatric and adult primary cases were 45% and 54%, respectively (OR, 0.79; 95% CI, 0.41-1.54). SIRs among pediatric primary cases with Alpha and non-Alpha lineage were 55% and 46%, respectively (OR, 1.52; 95% CI, 0.51-4.53). SIRs among pediatric and adult household contacts were 55% and 49%, respectively (OR, 1.01; 95% CI, 0.68-1.50). Among pediatric contacts, no significant differences in the odds of acquiring infection by demographic or household characteristics were observed. Conclusions Household transmission of SARS-CoV-2 from children and adult primary cases to household members was frequent. The risk of secondary infection was similar among child and adult household contacts. Among children, household transmission of SARS-CoV-2 and the risk of secondary infection was not influenced by lineage. Continued mitigation strategies (eg, masking, physical distancing, vaccination) are needed to protect at-risk groups regardless of virus lineage circulating in communities.

While risk of fomite transmission of SARS-CoV-2 is considered low, there is limited environmental data within households. This January-April 2021 investigation describes frequency and types of surfaces positive for SARS-CoV-2 by real-time reverse transcription polymerase chain reaction (RT-PCR) among residences with ≥1 SARS-CoV-2 infection, and associations of household characteristics with surface RT-PCR and viable virus positivity. Of 1232 samples from 124 households, 27.8% (n = 342) were RT-PCR positive with nightstands (44.1%) and pillows (40.9%) most frequently positive. SARS-CoV-2 lineage, documented household transmission, greater number of infected persons, shorter interval between illness onset and sampling, total household symptoms, proportion of infected persons ≤12 years old, and persons exhibiting upper respiratory symptoms or diarrhea were associated with more positive surfaces. Viable virus was isolated from 0.2% (n = 3 samples from one household) of all samples. This investigation suggests that while SARS-CoV-2 on surfaces is common, fomite transmission risk in households is low.

Introduction:Mitigation behaviors are key to preventing SARS-CoV-2 transmission. We identified the behaviors associated with secondary transmission from confirmed SARS-CoV-2 primary cases to household contacts and described the characteristics associated with reporting these behaviors.Methods:Households with confirmed SARS-CoV-2 infections were recruited in California and Colorado from January to April 2021. Self-reported behaviors and demographics were collected through interviews. We investigated behaviors associated with transmission and individual and household characteristics associated with behaviors using univariable and multivariable logistic regression with generalized estimating equations to account for household clustering.Results:Among household contacts of primary cases, 43.3% (133 of 307) became infected with SARS-CoV-2. When an adjusted analysis was conducted, household contacts who slept in the same bedroom with the primary case (AOR=2.19; 95% CI=1.25, 3.84) and ate food prepared by the primary case (AOR=1.98; 95% CI=1.02, 3.87) had increased odds of SARS-CoV-2 infection. Household contacts in homes ≤2,000 square feet had increased odds of sleeping in the same bedroom as the primary case compared with those in homes >2,000 square feet (AOR=3.97; 95% CI=1.73, 9.10). Parents, siblings, and other relationships (extended family, friends, or roommates) of the primary case had decreased odds of eating food prepared by the primary case compared with partners.Conclusions:Sleeping in the same bedroom as the primary case and eating food prepared by the primary case were associated with secondary transmission. Household dimension and relationship to the primary case were associated with these behaviors. Our findings encourage innovative means to promote adherence to mitigation measures that reduce household transmission.

BACKGROUND:Between November 2021 and February 2022, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta and Omicron variants co-circulated in the United States, allowing for co-infections and possible recombination events. METHODS:We sequenced 29,719 positive samples during this period and analyzed the presence and fraction of reads supporting mutations specific to either the Delta or Omicron variant. FINDINGS:We identified 18 co-infections, one of which displayed evidence of a low Delta-Omicron recombinant viral population. We also identified two independent cases of infection by a Delta-Omicron recombinant virus, where 100% of the viral RNA came from one clonal recombinant. In the three cases, the 5' end of the viral genome was from the Delta genome and the 3' end from Omicron, including the majority of the spike protein gene, though the breakpoints were different. CONCLUSIONS:Delta-Omicron recombinant viruses were rare, and there is currently no evidence that Delta-Omicron recombinant viruses are more transmissible between hosts compared with the circulating Omicron lineages. FUNDING:This research was supported by the NIH RADx initiative and by the Centers for Disease Control Contract 75D30121C12730 (Helix).

Objective The successful response to COVID-19 would require an effective public health surveillance and management, technical expertise, and smart mobilization of many resources. This study aimed to analyze COVID-19 epidemiological profile with respect to the changing case definitions and testing performance. Methods Data were extracted from the electronic notification system (Tarassud) from 1 January to 13 July 2020. The information used was primarily composed of details regarding samples, age, sex, nationality, residence and hospital admission. Bivariate and multivariable analyses were used to determine the odds ratios (ORs) and 95% confidence intervals (CI). Results A total of 20,377 COVID-19 tests were performed from 15 March to 13 July 2020. Most (4885; 87.2%) positive tests were among Omanis, and 3602 (64.3%) were in males. The median age of people tested was 30 (standard deviation 16.5) years (interquartile range 22, 38). The odds of acquiring infection increased with age. The ORs of infection for groups of 30–39, 40–49 and over 50 years of age were 2.75 (95% CI 2.42–3.13), 3.29 (95% CI 2.85–3.79) and 3.34 (95% CI 2.89–3.87), respectively. Likewise, admission rates increased with age; the ORs for the groups 40–49 and ≥ 50 years of age were 4.45 (95% CI1.35–14.67) and 16.53 (95% CI 5.18–52.75), respectively. Multivariate analysis identified Barka 1.4 (95% CI 1.33–2.27) and Al Musanaah 1.4 (95% CI 1.07–1.84) as having the highest risk of transmission. Of 5604 people with positive results, 160 (2.9%) required hospital admission, and males had higher odds of admission, with an OR of 1.5 (95% CI 1.05–2.13). The average delay in the release of test results further increased after the fourth and fifth case definitions were adopted (2.04 and 2.56 days, respectively). Conclusion Age was a significant factor associated with infection and hospital admission. Transmission occurred mainly among Omanis, and Barka and Al Musanaah reported the highest rates of transmission. Prioritization of testing accessibility should continually be assessed for high-risk groups, particularly when resources become limited.

Abstract Background In December 2020, B.1.1.7 lineage of SARS-CoV-2 was first detected in the United States and has since become the dominant lineage. Previous investigations involving B.1.1.7 suggested higher rates of transmission relative to non-B.1.1.7 lineages. We conducted a household transmission investigation to determine the secondary infection rates (SIR) of B.1.1.7 and non-B.1.1.7 SARS-CoV-2 lineages. Methods From January–April 2021, we enrolled members of households in San Diego County, CA, and Denver, CO metropolitan area (Tri-County), with a confirmed SARS-CoV-2 infection in a household member with illness onset date in the previous 10 days. CDC investigators visited households at enrollment and 14 days later at closeout to obtain demographic and clinical data and nasopharyngeal (NP) samples on all consenting household members. Interim visits, with collection of NP swabs, occurred if a participant became symptomatic during follow-up. NP samples were tested for SARS-CoV-2 using TaqPath™ RT-PCR test, where failure to amplify the spike protein results in S-Gene target failure (SGTF) may indicate B.1.1.7 lineage. Demographic characteristics and SIR were compared among SGTF and non-SGTF households using two-sided p-values with chi-square tests; 95% confidence intervals (CI) were calculated with Wilson score intervals. Results 552 persons from 151 households were enrolled. 91 (60%) households were classified as SGTF, 57 (38%) non-SGTF, and 3 (2%) indeterminant. SGTF and non-SGTF households had similar sex distribution (49% female and 52% female, respectively; P=0.54) and age (median 30 years, interquartile range (IQR 14–47) and 31 years (IQR 15–45), respectively). Hispanic people accounted for 24% and 32% of enrolled members of SGTF and non-SGTF households, respectively (p=0.04). At least one secondary case occurred in 61% of SGTF and 58% of non-SGTF households (P=0.66). SIR was 52% (95%[CI] 46%-59%) for SGTF and 45% (95% CI 37%-53%) for non-SGTF households (P=0.18). Conclusion SIRs were high in both SGTF and non-SGTF households; our findings did not support an increase in SIR for SGTF relative to non-SGTF households in this setting. Sequence confirmed SARS-CoV-2 samples will provide further information on lineage specific SIRs. Disclosures All Authors: No reported disclosures

From the Field is a semi-regular column that explores what it means to be a local health professional on the front lines of an emergency. Typically, National Association of County and City Health Officials (NACCHO) members share their stories of preparing for and responding to disasters, epidemics, and other major health issues. Through exploring the analysis of the challenges faced and the solutions developed, readers can learn how these public health champions keep their communities safe even in extreme situations. Readers may submit topics of interest to jfox46@jhu.edu .

Introduction Multidrug-resistant organisms (MDROs) have been a major concern in King Saud Medical City (KSMC) recently. The number of cases with colistin resistance was growing rapidly in the first half of 2016, challenging the infection control practices and mandating a thorough outbreak investigation. The objective of this study was to determine the extent of the outbreak, identify potential risk factors and prevent further increase in the rates of MDROs. Methods Reviewing the medical records of the 22 admitted cases with colistin resistance using an abstraction form composed of demographical data, comorbidities, details of current admissions, and procedures. Also, tracking patients' movements in the hospital, reviewing all cultures isolates, and reviewing the surveillance and infection control strategies. Results Mean age was 49.71±17.824 (20-79 years), 90.9% were males, 63.6% cases admitted under medical unit. The average duration of stay in the ED was 1.23 day. Over 2/3 had hypertension and diabetes mellitus. Majority of patients staying between 20-40 days in the hospital & the average number of days until developing colistin resistance was 44.18. Resistance was solely related to two organisms that were Acinetobacter baumanni (59.1%) and Klebsiella pneumoniae (40. 9%). Ventilators and folly's catheters were equally (95.5%) used by 21 patients. The most common site of infection was respiratory (41.3%), of which most were sputum samples. Resistance of over 75% is recorded by antibiotics like tazocin, ciprofloxacin, imepenen and oxacillin. Conclusion The uncontrolled use of antibiotics, prolonged stay in the Intensive Care Unit (ICU), frequent uses of different devices, are the potential risk factors of developing colistin resistance.