Predicting Postsurgical Complications of Peripheral Nerve Decompression: NSQIP Analysis of Frailty Measures Versus Historic Proxies

Background

Peripheral nerve decompression (PND) is generally safe, and newer techniques allow frail patients to undergo PND at less common sites. Current literature suggests patient frailty measures may more accurately predict postsurgical complications versus other proxies, but no current literature examines frailty in PND.

Methods

The authors reviewed data from the National Surgical Quality Improvement Program for patients who underwent PND outside the most common sites from 2013 to 2019. The modified 5-Item Frailty Index (mFI-5) and modified Charlson Comorbidity Index (mCCI) scores were calculated, and complications data were gathered. Age, body mass index (BMI), major comorbidities, American Society of Anesthesiologists class, and frailty were compared as predictors of all-cause 30-day complications, 30-day surgical site complications, length of stay, and complication severity, using univariate and multivariate logistic regression.

Results

Of 1120 patients, the mean age was 51.3 (15.4) years and mean BMI was 30.6 (7.0) kg/m2. Patients were predominantly white and healthy. The complication rate was 3.4%. All-cause complications were predicted by ≥3 major comorbidities (odds ratio [OR], 95% confidence interval [CI]: 6.26, 1.36-21.32; P = .007), followed by mFI-5 score and mCCI score. Complication severity was associated with major comorbidities and mFI-5 score, while length of stay was most strongly predicted by age ≥ 65 years (OR, 95% CI: 2.17, 1.37-3.42; P = .0008) and mCCI score of 3 (OR, 95% CI: 1.77, 1.01-3.05; P = 0.041). The only risk factor for readmission was mFI-5 score of 1 (OR, 95% CI: 7.00, 1.68-47.16; P = .016).

Conclusions

Frailty and risk proxies may predict postoperative complications in PND at uncommon sites. Use of frailty indices may expand the age range of patients offered PND. Further research is necessary to delineate contributing risk factors and to clarify 24-hour observation and admissions.

The Expanding Utility of Robotic-Assisted Flap Harvest in Autologous Breast Reconstruction: A Systematic Review

The expansion of robotic surgery has led to developments in robotic-assisted breast reconstruction techniques. Specifically, robotic flap harvest is being evaluated to help maximize operative reliability and reduce donor site morbidity without compromising flap success. Many publications are feasibility studies or technical descriptions; few cohort analyses exist. This systematic review aims to characterize trends in robotic autologous breast reconstruction and provide a summative analysis of their results. A systematic review was conducted using PubMed, Medline, Scopus, and Web of Science to evaluate robot use in breast reconstruction. Studies dated from 2006 to 2022 were identified and analyzed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Full-text, peer-reviewed, English-language, and human subject studies were included. Non-breast reconstruction articles, commentary, expert opinion, editor's letter, and duplicate studies were excluded. A total of 17 full-text articles were analyzed. The two robotic breast procedures identified were the deep inferior epigastric perforator (DIEP) and the latissimus dorsi (LD) flap. Results showed comparable complication rates and increased operative times compared to NSQIP data on their corresponding open techniques. Additional findings reported in studies included patient reported outcomes, incision lengths, and downward trends in operative time with consecutive procedures. The available data in the literature confirms that robotic surgery is a promising alternative to traditional open methods of breast reconstruction following mastectomy.

"Frailty Indices Outperform Historic Risk Proxies as Predictors of Post-Abdominoplasty Complications: An Analysis of a National Database"

BACKGROUND

While age, BMI, and major comorbidities were historically used as predictors of surgical risk, recent literature supports patient frailty as a more accurate predictor. Database studies and chart reviews support the modified Charlson Comorbidity Index (mCCI) and the Modified 5-Item Frailty Index (mFI-5) as predictors of postsurgical complications in plastic surgery. The authors hypothesized that the mFI-5 and mCCI are more predictive of abdominoplasty complications than historic risk proxies.

METHODS

A retrospective review of the NSQIP database was performed, for abdominoplasty patients from 2013 to 2019. Demographics, comorbidities, and complications were gathered. The mFI-5 and mCCI scores were calculated per patient. Age, BMI, major comorbidities, ASA class, mFI-5 score, and mCCI score were compared as predictors of all-cause 30-day complications, 30-day surgical site complications, length of stay, and aggregate Clavien-Dindo complication severity score.

RESULTS

Of 421 patients, the strongest predictors for all-cause complications and complication severity were mCCI score ≥ 3 and mFI-5 score ≥2. mFI-5 score was the strongest predictor of unplanned reoperation. Length of stay was best predicted by age ≥ 65. The only predictor of surgical site complications was BMI ≥ 30.0. Smoking was predictive of complication severity, but not any other outcome.

CONCLUSIONS

The mFI-5 and mCCI are stronger outcome predictors than historically-used factors, which showed little predictive value in this cohort. While the mCCI is a stronger predictor than the mFI-5, the mFI-5 is easily calculated during an initial consultation. Surgeons can apply these tools to aid in risk stratification for abdominoplasty.

Did the National Ban on Bacitracin Irrigation Affect Infection Rates in Implant-Based Breast Reconstruction? An Analysis of a National Database

INTRODUCTION

The current standard of practice in implant-based breast reconstruction is irrigation of the mastectomy pocket with antimicrobial solution before implant placement. Prior to being banned and formally recalled in January 2020, bacitracin was a very commonly utilized antibiotic. This study characterizes the effects of the national bacitracin ban on implant-based breast reconstruction infection rates by using a nationwide database to compare complication rates before and after bacitracin was banned.

MATERIALS AND METHODS

The American College of Surgeons National Surgical Quality Improvement (ACS-NSQIP) database was queried retrospectively for all patients who underwent implant-based breast reconstruction before the bacitracin ban (2012-2019) and afterwards (2020). Demographics, comorbidities, and complications were collected. Univariate analysis and multivariate analysis were conducted to determine if there were significant changes in wound complications, local wound infections, and systemic infections between the 2 case-control matched cohorts.

RESULTS

A total of 37,126 patients were in the pre-ban cohort and 6333 patients were in the post-ban cohort. Before matching, there were significant differences in race distribution, BMI, ASA class, inpatient vs. outpatient status, preoperative smoking, and preoperative diabetes mellitus (all P < .05). After case-control matching, there were 6313 patients in each cohort. Univariate analysis revealed differences in postoperative superficial and organ space surgical site infection, wound complications/infections, all cause complications, and reoperations (all P < .05). Multivariate analysis showed that patients who underwent breast reconstruction before the ban had decreased odds of having wound infections, related infections, all cause complications, and reoperations (all P < .05).

CONCLUSION

This study provides a macroscopic view into the effects of the formal injectable bacitracin ban on breast reconstruction outcomes. Patients who underwent implant-based breast reconstruction after the ban of injectable bacitracin had higher odds of developing wound infections, related infections, and reoperations. More study into suitable alternatives to injectable bacitracin for surgical site antimicrobial irrigation is warranted.

Changes in Burn Surgery Operative Volume and Metrics due to COVID-19

Due to COVID-19, hospitals underwent drastic changes to operating room policy to mitigate the spread of the disease. Given these unprecedented measures, we aimed to look at the changes in operative volume and metrics of the burn surgery service at our institution. A retrospective review was conducted for operative cases and metrics for the months of March to May for 2019, 2020, and 2021, which correspond with pre-COVID, early COVID (period without elective cases), and late COVID (period with resumed elective cases). Inclusion criteria were cases related to burns. Case types and operative metrics were compared amongst the three time periods. Compared to the hospital, the burn service had a smaller decrease in volume during early COVID (28.7% vs. 50.1%) and exceeded pre-pandemic volumes during late COVID (+21.8% vs. -4.6%). There was a significant increase in excision and grafting cases in early and late COVID periods (p < .0001 and p < .002). There was a significant decrease in laser scar procedures that persisted even during late COVID (p < .0001). The projected and actual lengths of cases significantly increased and persisted into late COVID (p < .01). COVID-19 related operating room closures led to an expected decrease in the number of operative cases. However, there was no significant decline in the number of burn specific cases. The elective cases were largely replaced with excision and grafting cases and this shift has persisted even after elective cases have resumed. This change is also reflected in increased operative times.

Carry That Weight! The Challenge of Managing Weight Changes During Inpatient Admission for Patients With Burn Injuries ≥20% TBSA

The hypermetabolic state of patients with ≥20% total body surface area (TBSA) causes loss of muscle mass and compromised immune function with delayed wound healing. Weight loss is most severe in patients with ≥20% TBSA with initial weight gain due to fluid resuscitation. The American Burn Association (ABA) proposed quality measures for burn injury admissions, including weight loss from admission to discharge. We assessed how our outcomes adhere to these measures and if they correlate with previously described results. We retrospectively reviewed adult admissions with ≥20% TBSA burn injuries from 2016 to 2021. Four groups were established based on %TBSA: 20% to 29% (Group 1), 30% to 39% (Group 2), 40% to 59% (Group 3), and ≥60% (Group 4). We assessed weight changes from admission to discharge and performed multivariate analyses to account for age, sex, total surgeries, and length of stay. Data from 123 patients revealed 40 with 20% to 29% TBSA, 29 with 30% to 39% TBSA, 33 with 40% to 59% TBSA, 21 with ≥60% TBSA. A significant difference in weight loss was observed when comparing Groups 1 and 2 and Groups 3 and 4 (Group 1: −3.63%, Group 2: −2%, Group 3: −9.28%, Group 4: −13.85%; P-value ≤ .05). Groups 3 and 4 had significantly longer lengths of stay compared to Groups 1 and 2 (Group 1: 32.16, Group 2: 37.5, Group 3: 71.13, Group 4: 87.18; P-value ≤ .01). Most patients that experienced weight loss during their admission had &lt;15% weight loss. We found no significant difference in outcomes for patients receiving oxandrolone vs not. The mean weight change was −11% for patients with an overall weight loss and +5% for patients with an overall weight gain. The significant difference between the two groups was admission body mass index (BMI; loss: 30.4 kg/m2, gain: 26.0 kg/m2; P-value ≤ .05). Patients with ≥20% TBSA suffer weight changes, likely due to metabolic disturbances. Increased length of stay and higher %TBSA may be associated with greater weight loss. Patients experiencing weight gain had lower admission BMI suggesting that patients with higher BMI are more prone to weight loss. Our findings support that patients with %TBSA ≥40 are unique, requiring specialized nutritional protocols and metabolic analysis.

85 Changes in Burn Surgery Operative Volume and Metrics Due to COVID-19

Introduction

Due to COVID-19, hospitals have had to undergo drastic changes to operating room (OR) policy to mitigate the spread of the disease. Elective surgeries were cancelled, and some ORs were repurposed to help withstand a surge of COVID-19 patients. Given these unprecedented measures, we aim to look at the changes in operative volume and metrics of the burn surgery service at our institution.

Methods

An IRB-approved single-institution retrospective review was conducted by querying our institutional OR database. We obtained case lists and OR metrics for the months of March to May for 2019, 2020, and 2021, which correspond with pre-COVID, early COVID (period without elective cases), and late COVID (period with resumed elective cases). Inclusion criteria were cases related to burns. These cases were then divided into the following groups: excision only, grafting only, excision and grafting, laser scar procedures, secondary reconstruction without grafting or flaps, secondary reconstruction with grafting, and secondary reconstruction with flaps. Types of cases and operative metrics were compared amongst the three time periods.

Results

The total number of cases performed by the entire hospital during 2019, 2020, and 2021 was 2375, 1184, and 2265 respectively. During those times, the burn surgery service performed 174, 124, and 212 total cases (138, 103, and 114 burn related cases) respectively. Compared to the hospital, the burn service had a smaller decrease in volume during early COVID (28.7% vs. 50.1%) and exceeded pre-pandemic volumes during late COVID (+21.8% vs. -4.6%). There was a significant increase in excision and grafting cases in early and late COVID periods (41, 84, 74 respectively; p < .0001 and p < .002). There was a significant decrease in laser scar procedures that persisted even during late COVID (69, 0, 14 respectively; p < .0001). The projected and actual lengths of cases significantly increased and persisted into late COVID (p < .01). The average length pre-COVID and late COVID were 109.9 ± 78.5 and 138.2 ± 79.2 minutes.

Conclusions

COVID-19 related OR closures lead to an expected decrease in the number of overall cases and elective cases. However, there was no significant decline in the number of burn specific cases performed. The elective cases were largely replaced with excision and grafting cases and this shift has persisted even after elective cases have resumed. This change is also reflected in increased operative times.

707 Invasive Non-Candida Fungal Infections in Acute Burns: A 13-Year Review of a Single Institution

Introduction

Burn patients have higher infection rates due to loss of the protective skin barrier. The past decade shows increased rates of burn infection with atypical invasive fungal organisms. After a recent trend of life-threatening atypical fungal burn infections at our hospital, we conducted this study to further characterize this.

Methods

We identified patients admitted to our burn center from January 2008 to June 2021, who developed fungal non-Candida burn infections while admitted. We gathered demographic data, burn injury details, surgical treatment course, and fungal and bacterial infection data. Descriptive statistics were used to characterize the data and identify trends.

Results

We identified 37 acute burn patients with atypical invasive fungal infections. Of these, 28 were infected with 1 species, and 9 were infected with multiple fungi.

Non-Candida fungi included Aspergillus (20), Fusarium (8), Mucor (6), and 11 other species. Three fungi were resistant to antifungals including amphotericin B. Other organisms included Candida (18), Enterococcus (13), Pseudomonas (9), and 19 other species. On average, patients were infected with 5 bacteria, had 13 antibacterial resistances, and required 6.5 antibacterials. There was one case of total-drug-resistant Pseudomonas aeruginosa. Every patient required Infectious Disease consultation. Eight patients became bacteremic and 1 became fungemic.

The average burn surface area was 35%. All patients required excisional treatment, with an average of 7 excisions, 7 coverage procedures, and 3.5 other procedures; 44% of patients required amputations for infection control. The most common complications were graft loss (39%), ventilator-associated pneumonia (28%), and death (28%). The median length of stay was 40 days (IQR = 89) for survivors and 28 days (IQR = 14) for nonsurvivors. All fatalities were from overwhelming polymicrobial infection. The average modified Baux score was 73 (± 28) for survivors and 102 (± 38) for nonsurvivors. All nonsurvivors had clean wounds without penetrating trauma.

Conclusions

Burn patients with atypical invasive fungal infections have severe polymicrobial infections and extreme antibiotic resistance. Patients may require, or fail, treatment with last-line antibiotic therapy and amputation. Early Infectious Disease consultation and aggressive treatment is critical. Further research may elucidate risk factors and ideal treatment patterns.

96 Poly-dl-lactide Copolymer-dressing Use on Burn Wounds and Skin Graft Donor Sites - An Institutional Review

Introduction

In burn surgical care, wound coverage and the corresponding dressing are paired to maximize the ability to promote re-epithelization, minimize pain and patient discomfort, dressing change frequency and overall cost. This dressing, a copolymer material based on DL lactic acid, has been described as a reliable alternative dressing for partial thickness burns as well as skin graft donor sites with comparable wound-healing quality and duration. Our aim is to assess outcomes results of this copolymer dressing at our institution, as applied to partial thickness burn wounds and graft donor sites.

Methods

We performed a retrospective analysis of 55 adult patients admitted between January 1, 2020 to August 25, 2021 for the treatment of partial thickness burns that were managed with a poly-DL-lactide copolymer skin substitute at the burn wound and/or autograft donor site. Three study groups were established based on application site: wound only (group 1), donor site only (group 2), and both (group 3). We assessed operative times, infections rates, complications, length of stay, readmission rates, and mortality.

Results

Preliminary data of 40 patients shows clinically similar results for analgesic requirements, operative length, and hospital LOS between group 1 and group 3. Group 2 showed higher analgesic requirements, lower operative times, a lower LOS, and lower readmission rates. Group 3 shows higher pain levels and longer operative times, when compared with groups 1 and 2, but lower readmission rates than group 1.

Conclusions

The poly-DL-lactide copolymer skin substitute offers reliable wound coverage for a partial thickness burns while also reducing frequency of dressing changes and associated pain correlating to reduced length of hospital stay and wound healing interval.

509 Why do elderly burn patients die? Analysis of early versus delayed ICU deaths, from 2014-2021

Introduction

Despite continued improvements in critical care, nutrition, and surgical technique, elderly patients with burn injury remain a vulnerable population, with increased mortality. The purpose of this study was to compare early versus late deaths in elderly burn patients admitted to the intensive care unit, to identify potential interventions that might improve survival.

Methods

We conducted a retrospective review of elderly patients (age >=60 years), who were admitted to an urban burn center ICU, with thermal and/or inhalation injury, over an 8-year period. Data were extracted from a prospectively maintained registry and verified through our electronic medical record. Patients who died less than 1 week after admission were compared with those who died after the first week. Univariate analysis was performed by 2-tailed Student’s T test and chi-square, with statistical significance assigned to p values < 0.05.

Results

From 2014-2021, we admitted 1322 patients to the burn ICU for thermal and/or inhalation injury. Mortality was 9.4% for patients >= 60 years of age, compared to 2.0% for patients < 60 (p< 0.001). The elderly patients who succumbed to their injury had a mean age of 75.3 years, TBSA 27.7%, modified Baux score of 111.3, and survival of 13.8 days. We observed a bimodal distribution of deaths, peaking on the first day after injury, and in the third week after admission, the most common cause of which, for both groups, was multisystem organ failure. Compared to the delayed deaths (n=21), patients who died within the first week (n=16) had an increased incidence of inhalation injury, a higher modified Baux score but similar age and TBSA, and lower baseline comorbidities and complications (TABLE).

Conclusions

Presence of inhalation injury and high modified Baux score, not necessarily age or %TBSA, was associated with early mortality in the elderly, after burn injury. Older patients who survive their initial resuscitation often succumb to complications related to baseline comorbidities. Improved management of these comorbidities, via the active involvement of geriatric medicine and palliative care, represents an opportunity to increase survival.

An Unusual Case of BIA-ALCL Associated with Prolonged/Complicated Biocell-Textured Expander, followed by Smooth Round Breast Implant Exposure, and Concurrent Use of Adalimumab

SUMMARY

Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) is a malignancy associated with textured breast implants. BIA-ALCL is typically restricted to the periprosthetic capsule, presenting as a unilateral recurrent seroma years after placement of a textured breast implant. Current estimates suggest an incidence of one in 3300 for patients with Allergan Biocell textured implants. As of February 6, 2019, U.S. Medical Device Reporting associated with BIA-ALCL showed 457 unique cases of BIA-ALCL, with 24 "unverified and potentially inaccurate" cases associated with a nontextured implant. As of February of 2019, there were 688 reported cases to date worldwide. To date, there are no published case reports of BIA-ALCL associated exclusively with smooth implants or with smooth implants after textured expanders, and there has been no reported smooth-only case in any registry, database, or journal worldwide. The authors present a case of BIA-ALCL associated with smooth round implants and textured tissue expanders. A 56-year-old woman was treated for left stage IIA invasive ductal carcinoma with bilateral mastectomies and immediate reconstruction with bilateral subpectoral textured tissue expanders. She underwent exchange to Mentor smooth-round implants, and completed adjuvant chemotherapy. Magnetic resonance imaging and examination 4.5 years after implant placement showed no abnormal findings. The patient had left breast trauma 5 years following implant placement while taking adalimumab, and developed an open wound requiring explantation. A recurrent seroma developed, and tested positive for BIA-ALCL on cytology. Surgical pathologic examination after total capsulectomy demonstrated stage IA BIA-ALCL. To the authors' knowledge, this is the first case report of BIA-ALCL in a patient with textured expanders followed by prolonged exposure to smooth round implants.

Prophylactic Bronchial Stump Support With Intrathoracic Muscle Flap Transposition

BACKGROUND

Bronchopleural fistula (BPF) is a dreaded complication of pulmonary resection. For high-risk patients, bronchial stump coverage with vascularized tissue has been recommended. The goal of this study was to report our experience with intrathoracic muscle transposition for bronchial stump coverage.

METHODS

A retrospective review of all patients who underwent intrathoracic muscle flap transposition as a prophylactic measure at our institution between 1990 and 2010 was conducted. Demographics, surgical characteristics, and complication rates were abstracted and analyzed.

RESULTS

A total of 160 patients were identified. The most common lung resections performed were pneumonectomy (n = 69, 43%) and lobectomy (n = 60, 38%). A total of 168 flaps were used where serratus anterior was the most common flap (n = 136, 81%), followed by intercostal (n = 14, 8%), and latissimus dorsi (n = 12, 7%). Ten patients (6%) developed BPF, and empyema occurred in 13 patients (8%). Median survival was 20 months, and operative mortality occurred in 7 patients (4%).

CONCLUSIONS

Reinforcement of the bronchial closure with vascularized muscle is a viable option for potentially decreasing the incidence of BPF in high-risk patients. Further randomized studies are needed to determine the efficacy of this technique for BPF prevention.

Intrathoracic Muscle Flap Transposition for the Management of Chronic Pulmonary Aspergillosis

BACKGROUND

The management of chronic pulmonary aspergillosis remains a challenge for thoracic and reconstructive surgeons. Different management options have been proposed with no consensus regarding the best treatment modality. The goal of this study is to report our experience with the use of intrathoracic muscle flaps for the management of pulmonary aspergillosis.

METHODS

We retrospectively reviewed all patients who underwent intrathoracic muscle flap transposition for the management of pulmonary aspergillosis between 1990 and 2010. Demographics, surgical characteristics, and treatment outcomes were collected and analyzed.

RESULTS

A total of 39 patients who underwent 48 muscle flaps were identified. The majority were classified as ASA 3 (n=30, 77%) or ASA 4 (n=8, 21%). Serratus anterior was the most common flap used (n=34), followed by latissimus dorsi (n=6) and pectoralis major (n=5). Flap loss was encountered in three (8%) patients (2 partial, 1 total). Bronchopleural fistula and empyema comprised the two most common intrathoracic complications (26%, 29% respectively). Median follow-up was 33 months (range, 0-216). Successful treatment was achieved in 77% of patients, while operative mortality was 23%.

CONCLUSION

The use of intrathoracic muscle flaps can be a helpful adjunct to surgical resection in the treatment of chronic pulmonary aspergillosis with low rates of flap loss.

Muscle Flap Transposition for the Management of Intrathoracic Fistulas

BACKGROUND

Intrathoracic fistulas pose unique challenges for thoracic and reconstructive surgeons. To decrease the incidence of fistula recurrence, pedicled flaps have been suggested to buttress the repair site. The authors aimed to report their experience with muscle flap transposition for the management of intrathoracic fistulas.

METHODS

A retrospective review of all patients who underwent intrathoracic muscle flap transposition for the management of intrathoracic fistulas from 1990 to 2010 was conducted. Patient demographics, surgical characteristics, and complication rates were abstracted and analyzed.

RESULTS

A total of 198 patients were identified. Bronchopleural fistula was present in 156 of the patients (79 percent), and 48 had esophageal fistula (24 percent). A total of 238 flaps were used, constituting an average of 1.2 flaps per patient. After the initial fistula repair, bronchopleural fistula complicated the course of 34 patients (17 percent), and esophageal fistula occurred in 13 patients (7 percent). Partial flap loss was identified in 11 flaps (6 percent), and total flap loss occurred in four flaps (2 percent). Median follow-up was 27 months. At the last follow-up, 182 of the patients (92 percent) had no evidence of fistula, 175 (89 percent) achieved successful chest closure, and 164 (83 percent) had successful treatment. Preoperative radiation therapy and American Society of Anesthesiologists score of 4 or greater were identified as risk factors for unsuccessful treatment.

CONCLUSIONS

Intrathoracic fistulas remain a source of major morbidity and mortality. Reinforcement of the fistula closure with vascularized muscle flaps is a viable option for preventing dehiscence of the repair site and can be potentially life-saving.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Flap Reconstruction of Gastrointestinal-to-Genitourinary Fistulas: A 20-Year Experience

Background Gastrointestinal-to-genitourinary fistulas may occur secondary to obstetric complications, radiation therapy, cancer without radiation, inflammatory bowel disease, or previous surgery. Flap reconstruction is useful for complex cases refractory to standard techniques, separating the fistula tracts to aid healing. The purpose of this study was to investigate outcomes and risk factors for complications in flap reconstruction of fistulas from several different etiologies performed over a 20-year period.

Methods All patients who underwent flap reconstruction between January 1995 and December 2014 were reviewed. Patient demographics, prior treatment failures, surgical indications, and comorbidities were obtained. Operative and postoperative data were collected, including flap type, length of stay, early and late complications, recurrences, and follow-up time. Operative success was defined as definitive treatment of the fistula without recurrence within 6 months.

Results There were 59 patients who underwent 66 reconstructions. The overall complication rate was 59.1%. Complications included infection (21%), dehiscence (17%), and partial flap loss (1.5%). Operative success rate was 51.5%. Smoking history (p = 0.021) and body mass index (BMI) > 35 (p = 0.003) were significantly associated with increased likelihood of postoperative complications following flap reconstruction in these patients. Additionally, fistulas due to cancer resections had a higher likelihood of postoperative complications compared with fistulas due to bowel disease or obstetric complications (p = 0.04).

Conclusion Flap reconstruction can be successfully used for complex or refractory gastrointestinal-to-genitourinary fistulas. However, considerable complication and recurrence rates were found in this population. Patients with a BMI > 35 and a history of smoking were at greatest risk in this cohort of experiencing postoperative complications.

Field evaluation of phostoxin and zinc phosphide for the control of zoonotic cutaneous leishmaniasis in a hyperendemic area, central Iran

BACKGROUND & OBJECTIVES

ZCL is a growing threat in many rural areas of Iran which involves 17 out of 31 provinces. This study was conducted from April to November 2011 for evaluation of the efficacy of phostoxin and zinc phosphide against rodents.

METHODS

Rodent control operations were carried out using phostoxin and zinc phosphide. To evaluate the effect of rodent control operation on the main vector density, an entomological survey was carried out. The effects of the operation on the disease incidence were also evaluated.

RESULTS

After intervention, the reduction rate of rodent burrows was 32.68% in the village treated with phostoxin and 58.14% in the village treated with zinc phosphide. The number of rodent holes in the control area showed 6.66-fold increase at the end of the study. The incidence of the disease decreased to 19.23 and 11.40 in areas treated with phostoxin and zinc phosphide, respectively. A total of 4243 adult sandflies were collected and identified. The most common and dominant species was Phlebotomus papatasi. In the village treated with phostoxin, the density of P. papatasi in outdoors was lower than indoors. Nevertheless, the density of P. papatasi in the village treated with zinc phosphide was higher in outdoors.

INTERPRETATION & CONCLUSION

It is concluded that phostoxin is less effective and has low safety in comparison with zinc phosphide, so that this rodenticide can be used only in special situations such as lack or ineffective rodenticides and only in the colonies far from human and animal dwelling places in small scales.

Interleukin 4 (IL-4) gene promoter polymorphisms in Rhombomys opimus, the main reservoir of zoonotic cutaneous leishmaniasis

Great gerbils (Rhombomys opimus) are the most common gerbils in center to northeast of Iran as well as central Asia and serve as reservoirs for the zoonotic agents, including Leishmania major, the principal etiologic agent of zoonotic cutaneous leishmaniasis (ZCL). The outcome of L. major infection in gerbils is not uniform. Among several immune-related factors including cytokine genes, the polymorphism in interleukin 4 (IL-4) promoter gene showed a great impact on outcome and pathological symptoms of L. major infection at least in mouse model. In this study gerbils' IL-4 promoter gene polymorphism is assessed. Specific primers were designed to develop a PCR-based assay to amplify IL-4 promoter gene to possibly define IL-4 promoter gene polymorphism in great gerbil populations with a range of Leishmania infection and symptoms collected from different foci of the central, north and northeast regions of Iran. The results showed that the designed primers amplify 689bp of the promoter gene. Sequence analysis of the promoter gene revealed five polymorphic sites assembly six haplotypes among the gerbil populations. Further studies are needed to assess whether or not the five polymorphisms cause different outcome phenotypes following infection with L. major in great gerbils. The data might be used to characterize the immune responses of R. opimus against L. major infection.

Wild rodents and their ectoparasites in Baluchistan area, southeast of Iran

During 2008-2009 a total of 67 individuals of rodents, Tetera indica, Meriones hurrianae, Meriones libycus and Gerbillus nanus were trapped in three areas, Bampor, Daman and Qasre Qand from Iranshahr and Nikshahr districts. There is a significant difference between comparative abundance of four species (P<0.05). A total of 1422 ectoparasites collected including 299 mites (21%), 127 fleas (8.9%), 972 lice (68.4%) and 24 ticks (1.7%). Significant findings amongst the ectoparasites is the lice group with three species identified, Laelaps accuninata, Andralaelaps hermophrodita and Paracheylaellaps pyriformis being the first record in the study areas. All four captured genera of rodents are known as main/ potential reservoir hosts of zoonotic cutaneous leishmaniasis. The migration habit of rodents may affect the spatial distribution of parasitic ticks and their transmitted diseases like CCHF, which has been reported in recent years from Sistan and Baluchestan province. Monitoring of rodent populations and their ectoparasites will help to predict the potential of zoonotic arthropod-borne diseases.

Baseline insecticide susceptibility data of Phlebotomus papatasi in Iran

BACKGROUND & OBJECTIVES

Phlebotomine sandflies (Diptera: Psychodidae) play main role in the transmission of different forms of leishmaniasis in the world. Phlebotomus papatasi is the main vector of zoonotic cutaneous leishmaniasis (ZCL) in Iran. There are several control measures for vector control using different classes of insecticides. The aim of this study was to breed the sandflies which were collected from a hyperendemic focus of the disease in central Iran in the laboratory condition and to determine its baseline susceptibility to commonly used insecticides.

METHODS

Sandflies were collected from the field and were reared in insectary. Susceptibility tests were carried out on their generation. Baseline susceptibility of sandflies to DDT and pyrethroids was evaluated based on LT50 values. A total of 1305 specimens were tested using different time intervals. The LT50 and LT90 values were measured according to the WHO standard tests. The results were plotted using probit analysis and regression lines.

RESULTS

The results against female sandflies revealed the LT50 values of 1312.66, 253.66, 36.04, 9.38 and 6 sec to DDT (4%), permethrin (0.75%), deltamethrin (0.1%), cyfluthrin (0.15%) and lambda-cyhalothrin (0.05%), respectively. The figures for male sandflies were 1200.97, 310.10, 18.63, 6.08 and 0.77 sec respectively to the above insecticides.

CONCLUSION

The results of this study could help to provide a clue for implementation of currently used insecticides. Furthermore, a specific guideline is needed for monitoring and evaluation of insecticide susceptibility test against sandflies.

Comparative study on the effectiveness of coumavec® and zinc phosphide in controlling zoonotic cutaneous leishmaniasis in a hyperendemic focus in central iran

BACKGROUND

Zoonotic cutaneous leishmaniasis (ZCL) is an increasing health problems in many rural areas of Iran. The aim of this study was to introduce a new alternative rodenticide to control the reservoirs of ZCL, its effect on the vector density and the incidence of the disease in hyperendemic focus of Esfahan County, central Iran.

METHODS

The study was carried out from January 2011 to January 2012. In intervention areas, rodent control operation was conducted using zinc phosphide or Coumavec®. Active case findings were done by house-to-house visits once every season during 2011-2012. To evaluate the effect of rodent control operation on the vector density, sand flies were collected twice a month using sticky traps.

RESULTS

The reduction rate of rodent holes in intervention areas with Coumavec® and zinc phosphide were 48.46% and 58.15% respectively, whereas in control area results showed 6.66 folds intensification. The Incidence of ZCL significantly reduced in the treated areas. Totally, 3200 adult sand flies were collected and identified in the intervention and control areas. In the treated area with zinc phosphide, the density of Phlebotomus papatasi was higher in outdoors in contrast with the treated area by Coumavec® which the density of the sand fly was higher in indoors.

CONCLUSION

Both rodenticides were effective on the incidence of ZCL and the population of the reservoirs as well. Coumavec® seems to be effective on the outdoor density of the vector. This combination of rodenticide-insecticide could be a suitable alternative for zinc phosphide while bait shyness or behavioral resistance is occurred.

Production and Purification of Anti-Rhombomys opimus Immunoglobulins

BACKGROUND

Zoonotic cutaneous leishmaniasis (ZCL) is an increasing public health problem in some endemic regions. Horseradish peroxidase (HRP) conjugated rabbit anti-Rhombomys opimus (R. opimus) Ig is needed for immunoblotting and ELISA tests used to explore the immune response of the rodents against the sand fly saliva. In this study, the production of HRP conjugated rabbit anti-R. opimus Ig was conducted for the first time.

METHODS

Rhombomys opimus Ig was purified from serum by protein G affinity chromatography column and injected into rabbit to produce anti-R. opimus Ig antibody. The titration of antibody against R. opimus Ig in rabbit serum was checked using indirect ELISA. Rabbit anti-R. opimus Ig was purified by Sepharose-4B-R. opimus Ig column. Reactivity of this antibody was assessed by indirect ELISA and was conjugated to HRP by periodate method.

RESULTS

Approximately 3.5 mg Ig was purified from 1 ml R. opimus serum using protein G affinity chromatography column. The molecular weight of purified R. opimus Ig was estimated about 150 kDa by SDS-PAGE. Nearly 2.3 mg rabbit anti-R. opimus Ig was purified from 1 ml immunized rabbit serum. The purified antibody was conjugated to HRP and the optimum titer of HRP conjugated rabbit anti-R. opimus Ig was determined as 1:8000 using direct ELISA.

CONCLUSION

HRP conjugated rabbit anti-Gerbil IgG has been produced by a few companies, but to our knowledge HRP conjugated rabbit anti-R. opimus Ig is not commercially available. Production of HRP conjugated rabbit anti-R. opimus Ig is considerably helpful for immunological studies of R. opimus, the main reservoir host of ZCL in Iran as well as some other countries.

Endoparasites of rodents and their zoonotic importance in germi, dashte-mogan, ardabil province, iran

BACKGROUND

In order to verify the infectivity of rodents with endoparasites in Germi (Dashte-Mogan, Ardabil Province) the current study was undertaken.

METHODS

Using live traps, 177 rodents were trapped during 2005-2007. In field laboratory, all rodents were bled prior to autopsy, frozen at -20°C, and shipped to the School of Public Health, Tehran University of Medical Sciences, Iran. In parasitological laboratory, every rodent was dissected and its different organs were examined for the presence of any parasite. Blood thick and thin smears as well as impression smears of liver and spleen were stained with Geimsa and examined microscopically.

RESULTS

Two species of rodents were trapped; Meriones persicus (90.4%) and Microtus socialis (9.6%). The species of parasites found in M. persicus and their prevalences were as follows: Hymenolepis diminuta (38.8%), Hymenolepis nana (2.5%), Trichuris sp.(40.6), Mesocestoides larva (=tetrathyridium) (3.1%), Capillaria hepatica (6.9%), Moniliformis moniliformis (11.3%), Syphacia obvelata (2.5%), Taenia endothoracicus larva (0.6%), Physaloptera sp. (0.6%), Dentostomella translucida (0.6%), Heligmosomum mixtum (0.6%), Strobilocercus fasciolaris(0.6%),and Aspiculuris tetraptera (0.6%). The species of parasites found in M. socialis and their prevalences were as follows: H. diminuta (17.6%), Trichuris sp. (5.9%), Mesocestoides larva (5.9%), S. obvelata (11.8%), S. syphacia (11.8%), H. mixtum (17.6%), and Aspiculuris tetraptera (11.8%). There were no statistical differences between male and female for infectivity with parasites in either M. persicus or M. socialis. No blood or tissue protozoan parasite was found in any of the rodents examined.

CONCLUSION

Among different species identified, some had zoonotic importance. Therefore, the potential health hazard of these species needs to be considered to prevent infectivity of humans.

Dynamics of Leishmania infection rates in Rhombomys opimus (Rodentia: Gerbillinae) population of an endemic focus of zoonotic cutaneous leishmaniasis in Iran

Zoonotic cutaneous leishmaniasis (ZCL) due to Leishmania major is a great public health problem in the Old World. Leishmania major is widely distributed in populations of rodents in arid and savannah regions. In this study, seasonal variation of natural infection with Leishmania parasites in Rhombomys opimus (Rodentia: Gerbillinae) population of an endemic focus of ZCL in Iran was monitored. The study was conducted from October 2007 to October 2008 in the central part of the country. Nested polymerase chain reaction (PCR) assay was used for the detection and identification of Leishmania parasites, and the results were confirmed by PCR-restriction fragment length polymorphism (RFLP). The results showed that Leishmania infection rate was 55.8% (29 out of 52 gerbils) using nested PCR. The highest and lowest Leishmania infection rates were observed in fall and summer, respectively. Gerbils that were found to be infected only with L. major were 5.8%, and that with Leishmania turanica were 23.1%. A mixed natural infection was seen in the rodents with L. major and L. turanica (21.2%), with L. major and L. gerbilli (1.9%), and with all the three species (3.9%). Leishmania major infection alone was seen in fall and winter whereas mixed infection of L. major and L. turanica was observed in all seasons except in summer. Leishmania turanica infection was observed throughout the year. It is concluded that L. major, L. gerbilli, and L. turanica circulate in the population of R. opimus in central part of Iran. Leishmania major infection is usually accompanied by L. turanica in naturally infected gerbils with the highest rate in fall. It is recommended that the role of L. turanica in the epidemiology and transmission of ZCL should be reconsidered.

Sand fly Surveillance within an Emerging Epidemic Focus of Cutaneous Leishmaniasis in Southeastern Iran

BACKGROUND

Cutaneous leishmaniasis due to Leishmania major has become a hot topic in Iran. The objective of this study was to determine some ecological aspects of sand flies in the study area.

METHODS

Sand flies were collected biweekly from indoors and outdoors fixed places in the selected villages, using 30 sticky paper traps from the beginning to the end of the active season of 2006 in Kerman Province, south of Iran. The flies were mounted and identified. Some blood fed and gravid female sand flies of rodent burrows and indoors were dissected and examined microscopically for natural promastigote infection of Leishmania parasite during August to September.

RESULTS

In total, 2439 specimens comprising 8 species (3 Phlebotomus and 5 Sergentomyia) were identified. The most common sand fly was P. papatasi and represented 87.1% of sand flies from indoors and 57.2% from outdoors. The activity of the species extended from April to end October. There are two peaks in the density curve of this species, one in June and the second in August. Natural promastigote infection was found in P. papatasi (12.7%).

CONCLUSION

Phlebotomus papatasi is considered as a probable vector among gerbils and to humans with a high percentage of promastigote infection in this new focus of cutaneous leishmaniasis. The Bahraman area which until recently was unknown as an endemic area seems now to represent a focus of zoonotic cutaneous leishmaniasis transmission in Iran.

Molecular epizootiology of rodent leishmaniasis in a hyperendemic area of iran

BACKGROUND

Zoonotic cutaneous leishmaniasis (ZCL) is an expanding disease and public health problem in Iran. In the current study, natural Leishmania infection rate and seasonal fluctuation of the infection in Rhombomys opimus population of a hyperendemic focus of ZCL in Iran was investigated.

METHODS

The study was conducted from October 2006 to October 2008 in Esfahan Province, central part of Iran. An extensive sampling of rodents using Sherman traps was done in different seasons. Nested PCR assay was used for detection and identification of Leishmania species and the results were confirmed using PCR-RFLP.

RESULTS

Leishmania infection rate was 58.6% (34 of 58) using nested PCR. 44.8% of the gerbils were infected only with L. turanica and 1.7% with L. gerbilli alone. A mixed natural infection with L. major and L. turanica was seen in 12.1% of the rodents. L. major infection alone was not seen in R. opimus population in the study area. The highest and lowest Leishmania infection rates were observed in fall and spring respectively. L. turanica infection was observed throughout the year whereas mixed infections with L. major and L. turanica was not seen in spring.

CONCLUSION

It is concluded that in the study area, L. major, L. gerbilli and L. turanica circulate in the population of R. opimus. Leishmania major infection usually accompanied by L. turanica in naturally infected gerbils with the highest rate in fall. It is recommended that the role of L. turanica in the epidemiology and transmission of ZCL be revisited.

Ectoparasites of rodents captured in bandar abbas, southern iran

BACKGROUND

Rodents play important role as host of ectoparasites and reservoir of different zoonotic diseases. The aim of this study was to asses the infestation of commensal rodents with ectoparasites in Bandar Abbas, a port city located in the northern part of the Persian Gulf in Iran.

METHODS

Rodents were captured using live traps during the study period in year 2007. After transferring the rodents to the laboratory, they were identified and then their ectoparasites were collected and mounted for species identification using appropriate systematic keys.

RESULTS

A total of 77 rodents were identified including Rattus norvegicus (74%), R. rattus (16.9%), Mus musculus (7.8%) and one hamster. Among all rodents, 40.3% were found infested with ectoparasites. A total of 69 ectoparasites were collected comprising flea, lice, mite and tick. Two species of fleas; Xenopsylla cheopis and X. astia were identified with higher index of X. astia. Two genera of ticks including Hyalomma sp. and Rhipicephalus sp. were identified. Laelaps nuttalli was the only mite found. The Polyplax spinulosa was considered as lice ectoparasite.

CONCLUSION

Among all arthropods collected, flea and lice had the most and the least frequency, respectively. Nearly all rodent species were infested with Xenopsylla. These fleas are important due to their role in plague and murine typhus transmission. Ticks are important due to their role in CCHF (Crimean-Congo Hemorrhagic Fever), theileriosis, babesiosis, anaplasmosis and ehrlichiosis transmission .Monitoring of ectoparaiste infestation is important for preparedness and early warning preparation for possible control of arthropod-borne diseases.

Study on Ectoparasites of Rhombomys opimus, the Main Reservoir of Zoonotic Cutaneous Leishmaniasis in Endemic Foci in Iran

BACKGROUND

Ectoparasites of mammalian hosts play an important role for transmission of diseases from the host reservoirs to human. The aim of this study was to determine the species composition and infestation parameters for parasitic arthropods associated with Rhombomys opimus.

METHODS

Ectoparasites of R. opimus were collected from seven endemic district of ZCL in Iran including Shirvan and Sfaraysen in North Khorasan Province, Kalaleh in Golestan Province, Damghan and Shahrood in Semnan Province, and Badrood and Habibabad in Isfahan Province. The areas of study were mainly desert and plain. Rodents were captured using Sherman life traps during active seasons from May to November 2008. Captured rodents were transported to laboratory and their ectoparasites were picked up using brushing against the fur of the rodents. Ectoparasites were stored in 70% ethanol for their preservation and then identified based on morphological characters.

RESULTS

Ectoparasites belonged to one flea species of Xenopsylla nuttalli and one mite species of Ornithonussus bacoti. The flea species with 75.3% was more common than the mite. O. bacoti might play an important role in transmission of rat mite dermatitis among R. opimus colony.

CONCLUSION

Results will provide an essential clue for combating zoonotic diseases in the region.

Karyosystematic and morphometric characterization of the rodents as reservoir hosts of zoonotic cutaneous leishmaniasis in an endemic focus of Isfahan Province, Iran

BACKGROUND & OBJECTIVES

Rodents belonging to Gerbillinae subfamily are the main reservoir hosts of zoonotic cutaneous leishmaniasis (ZCL) in Iran. Regarding the important role of these rodents in the maintenance of Leishmania major in the nature, their identification with morphometric, cytogenetic and molecular methods seems to be essential. The karyotype study of these species, captured from a new focus of zoonotic cutaneous leishmaniasis located in the south of Isfahan Province was carried out in 2007.

METHODS

Twenty specimens containing seventeen Meriones persicus and three Nesokia indica were captured from Mobarakeh rural district south of Isfahan. Giemsa-stained karyotypes of these two species were prepared from bone marrow chromosome preparations. Systematic important characters of the body and cranium (incisors, molars, occipitonasal, condylobasal, zygomatic, tympanic bullae, etc.) of these rodents were studied. Cranium size was measured using a Vernier calipers.

RESULTS

Specimens of M. persicus and N. indica had 2n = 42. The karyotype study of these species included metacentric, sub-metacentric and acrocentric chromosomes. Morphological studies were completely matched with the reported characters of these species and further confirmed the diagnoses.

INTERPRETATION & CONCLUSION

Based on the results of this study, M. persicus and N. indica are two completely differentiated rodents species that were collected from a new focus and they can also be differentiated morphologically.

Evaluation of deltamethrin-impregnated bed nets and curtains for control of zoonotic cutaneous leishmaniasis in a hyperendemic area of Iran

In the study carried out in the rural district of Borkhar (Isfahan, Iran) from March 2003 to March 2004 efficacy of deltamethrin impregnated bed nets (IBs) and curtains (ICs), polyester mesh size 156 holes/ inch2, (25 holes/cm2) were compared to that of non-impregnated bed nets (NIBs) and curtains (NICs), in relation to zoonotic cutaneous leishmaniasis (ZCL) control. Deltamethrin impregnated bed nets and curtains at 25 mg a.i./m2 were distributed among 168 households in one of the villages and NIBs plus NICs among the same number of households in another village. In the third village similar numbers of households were used as control. Health education messages were disseminated to ensure the population's compliance with the proper use of bed nets and curtains in the two intervention areas. Entomological surveys using sticky paper traps were carried out in ten households in each village for the collection of sand flies from indoors and outdoors, every two weeks to assess the impact of insecticide impregnated bed nets and curtains on the density of Phlebotomus papatasi. Deltamethrin susceptibility tests and also bioassay tests were carried out on this species by WHO standard method. Case findings were done by house-to-house visits once a season and all the inhabitants of the selected households in each village were examined. The results showed that IBs and ICs can provide a definite personal protection against sand fly bites and interrupted the transmission of ZCL in the intervention village. NIBs and NICs did not provide any protection against the disease. There was no significant difference in monthly density of P. papatasi in indoors and outdoors among the villages (P > 0.05). Susceptibility tests showed that this species was susceptible to deltamethrin in the field population in the area. Bioassays confirmed that the treated nets with deltamethrin remain effective for more than three months and was an excellent mean of individual protection. It is recommended that IBs and ICs can be used widely in the control of ZCL in other similar foci such as hyperendemic and mesoendemic areas of Iran.

Characterization of Leishmania infection in rodents from endemic areas of the Islamic Republic of Iran

Between 1991-2000, Leishmania species were isolated and characterized by isoenzyme and molecular analysis from rodents caught in various parts of the Islamic Republic of Iran. In areas endemic for cutaneous leishmaniasis, parasites were observed by direct microscopy in smears from 18.6% of 566 specimens. L. major was isolated from 4 species: Rhombomys opimus, Meriones libycus, Tatera indica and Mer. hurrianae. L. turanica was isolated from R. opimus for the first time in this country. In endemic areas of visceral leishmaniasis, parasites were observed in liver and spleen from 13.7% of 504 rodents. Two species were positive on culture; promastigotes isolated from Mer. persicus were characterized as L. donovani zymodeme LON50 and from Mesocricetus auratus as L. infantum LON49.

Epidemiological study in a new focus of cutaneous leishmaniasis in the Islamic Republic of Iran

An outbreak of cutaneous leishmaniasis (CL) in Sabzevar county prompted this study of the epidemiology and the ecology of vectors and reservoirs. Examination of 541 schoolchildren showed rates of 9.4% for scars and 5.9% for ulcers. Among 807 inhabitants of 4 villages, 10.4% had scars and 3.0% had active lesions. The most highly infected age group was 0-4 years with a rate of 5.9%. A total of 12 849 sandflies representing 7 species were collected in the study area. Leptomonad infection was found in Phlebotomus papatasi, P. caucasicus and Sergentomyia sintoni. Parasites from man, P. papatasi and Rhombomys opimus, were isolated and characterized as Leishmania major. Based on this survey, this is an epidemic of zoonotic CL, with R. opimus the main reservoir host, and P. papatasi the main vector.

Epidemiological study in a new focus of cutaneous leishmaniosis due to Leishmania major in Ardestan town, central Iran

An endemic focus of zoonotic cutaneous leishmaniosis caused by Leishmania major zymodeme MON-26 was identified in Ardestan town central Iran, during 1998-99. Among 1960 school children examined over a 1-year period of time, 0.92% had evidence of active lesions and 1.53% had scar indicative of past infection. The incidence of the disease among school children was 3.2 per thousand in 1998. In a separate study, the incidence of infection among 100 households in an area with a population of 460 persons showed 3.26% for scars and 1.3% for ulcers. The most highly infected age group was 10-14 with a rate of 2.74%. Meriones libycus (93.3%) and Nesokia indica (6.7%) were present around the town of Ardestan. Both were found to be infected with Leishmania. Two out of 28 M. libycus (7.1%) and one out of two N. indica had positive results. M. libycus is probably the principal reservoir host of zoonotic cutaneous leishmaniosis in this area. Fourteen dogs appeared to be uninfected because examination showed no active lesion or scar. Most probably Phlebotomus papatasi is the vector because about 93% of indoor sandflies were of this species. The active season of sandflies was from late May to late October. Economic changes in this area of Iran may have contributed to this outbreak of cutaneous leishmaniosis.

Field trial for the control of zoonotic cutaneous leishmaniosis in Badrood, Iran

BACKGROUND

Due to the resurgence of zoonotic cutaneous leishmaniosis (ZCL) in some nonendemic areas of Iran, extensive studies have been conducted on the epidemiology of the disease in different parts of the country in recent years. The objective of this study was to determine the effects of rodent control on the reduction of the incidence of ZCL in an endemic area in Badrood, Iran.

PATIENTS AND METHODS

A survey was carried out in a circle around two villages between April 1997 and January 1999. The control strategy adopted in 1997 consisted of the destruction of the colonies of gerbilline rodents by digging in a radius of 500 m from houses in the intervention area. Opened burrows were baited with zinc phosphide. One village was used as control. Evaluation was made in 1998 and no other control measures were carried out in the area. Case findings were done by house-to-house visits once every season during 1997 and 1998, and all the inhabitants of the selected villages were examined.

RESULTS

The average reduction of rodent holes was calculated at 87.4% one year after the first baiting in the intervention area. Changes in the number of rodent holes and the incidence of the disease in the intervention and control villages were statistically significant (P-value <0.000001).

CONCLUSION

Our evaluation demonstrated that the control program reduced the incidence of ZCL 12-fold in the treated village compared to the control at the end of the first year of operation, and to more than one-fifth of its original level after two years. The results show that the field control method is very effective in destroying rodents and reducing the incidence of ZCL on a small scale and in special circumstances.

Entomological survey of sandflies (Diptera: Psychodidae) in a new focus of zoonotic cutaneous leishmaniosis in Iran

A total of 22,982 sandflies representing six species were collected using sticky (oiled) paper traps in Badrood rural district, Natanz county from May 1995 to May 1996. Phlebotomus papatasi was the predominant species. The average indoor resting density of P. papatasi ranged from 11.8 (May 1995) to 135.8 per 10 traps (September 1995). The average indoor resting density of this species varied between 39.7-701.3 per 10 traps in May and September, respectively in 1995. The activity of P. papatasi starts from late April or early May and extends to mid October with two peaks, one in mid or late June and the second one in early or mid September. Natural leptomonad infection was found in P. papatasi and Sergentomyia sintoni. P. papatasi could be a vector of humans and gerbils and it is susceptible to DDT in this area.

Meriones libycus and Rhombomys opimus (Rodentia: Gerbillidae) are the main reservoir hosts in a new focus of zoonotic cutaneous leishmaniasis in Iran

Following an epidemic of zoonotic cutaneous leishmaniasis (ZCL) around Badrood city, central Iran, Meriones libycus were found to be naturally infected with Leishmania major zymodeme MON-26 (= LON-1) in the villages of Matinabad and Fami, 12 km north-west of Badrood. This is the first isolation and characterization of L. major from M. libycus in Iran, in an area where ZCL has been present recently. M. libycus is probably the principal reservoir host in this area, but the main reservoir host further east is Rhombomys opimus. Parasites were not found in Hemiechinus auritis. The main, proven vector to humans and gerbils is Phlebotomus (Phlebotomus) papatasi. The close contact between vectors and reservoirs creates a very efficient cycle for the transmission of the disease.