Concordancia entre dos escalas para evaluar la clasificación del riesgo de eventos tromboembólicos y el requerimiento de profilaxis farmacológica en el posparto / Agreement between two scales used for assessing risk classification for thromboembolic events and the requirement of postpartum pharmacological prophylaxis

RESUMEN Objetivos: Establecer la concordancia para evaluar el requerimiento de profilaxis farmacológica en el puerperio entre la escala del Rojal College Obstetricians and Gynaecologists y la escala de la guía colombiana en una institución de cuarto nivel en Bogotá, Colombia. Materiales y métodos: Estudio de concordancia diagnóstica ensamblado sobre un estudio transversal. Se incluyeron mujeres embarazadas con 24 o más semanas de gestación que ingresaron para inducción de trabajo de parto, en trabajo de parto activo, para cesárea electiva, o que requirieron cesárea de urgencia, hospitalizadas entre el 1 de marzo y 30 de abril de 2021 en una institución privada de alta complejidad en Bogotá, Colombia. Se realizó un muestreo por conveniencia. Se midieron variables demográficas, factores de riesgo, clasificación del riesgo y profilaxis farmacológica según las dos escalas. Se calculó la prevalencia de los factores de riesgo por cada escala y la concordancia en la indicación de la profilaxis entre las dos escalas por medio del valor de kappa ponderado. Resultados: Se incluyeron 320 pacientes. La escala del Royal College Obstetricians and Gynaecologists clasificó al 54,7 % de las pacientes en riesgo bajo, riesgo intermedio al 42,5 % y riesgo alto al 2,8 %. La escala colombiana clasificó al 80 % de las pacientes en riesgo bajo, 17,2 % riesgo intermedio, 2,2 % riesgo alto y 0,6 % con riesgo muy alto. El valor kappa ponderado para la concordancia para indicación fue de 0,47 (IC 95 %: 0,38-0,56). Conclusiones: La concordancia de las dos escalas para definir requerimiento de profilaxis farmacológica en el posparto tiene un acuerdo moderado. Se considera es necesario validar los criterios de clasificación del riesgo de la escala colombiana en una segunda cohorte, además evaluar la capacidad predictiva de la herramienta de la guía colombiana en diferentes puntos de corte en términos de las consecuencias de falsos positivos y negativos.

ABSTRACT Objectives: To determine agreement in assessing the need for postpartum pharmacological prophylaxis between the scale of the Royal College of Obstetricians and Gynaecologists and the Colombian guideline scale in a Level IV institution in Bogota, Colombia. Material and methods: Diagnostic agreement study assembled on a cross-sectional study. The included population consisted of pregnant women with 24 or more weeks of pregnancy admitted between March 1 and April 30 of 2021 to a high complexity private institution in Bogotá, Colombia, for labor induction, in active labor, for elective cesarean section, or who required urgent cesarean section. Convenience sampling was used. Measured variables included demographics, risk factors, risk classification and pharmacological prophylaxis according to the two scales. The prevalence of risk factors for each scale was estimated and agreement regarding prophylaxis indication between the two scales was measured using the weighted kappa value. Results: Overall, 320 patients were included. According to the scale of the Royal College Obstetricians and Gynaecologists, 54.7 % patients were classified as low risk, 42.5 % as intermediate risk and 2.8 % as high risk. The Colombian scale classified 80 % of patients as low risk, 17.2 % as intermediate risk, 2.2 % as high risk, and 0.6 % as very high risk. The weighted kappa value for agreement regarding the indication was 0.47 (95 % CI: 0.38-0.56). Conclusions: Agreement between the two scales to determine the need for postpartum pharmacological prophylaxis is moderate. Risk classification criteria for the Colombian scale should be validated in a second cohort. Moreover, the predictive ability of the Colombian guideline tool should be assessed at different cut-off points in terms of the consequences of false positive and false negative results.

Enoxaparin titrated by anti-Xa levels reduces venous thromboembolism in trauma patients.

BACKGROUND: Trauma is a major risk factor for the development of a venous thromboembolism (VTE). After observing higher than expected VTE rates within our center's Trauma Quality Improvement Program data, we instituted a change in our VTE prophylaxis protocol, moving to enoxaparin dosing titrated by anti-Xa levels. We hypothesized that this intervention would lower our symptomatic VTE rates. METHODS: Adult trauma patients at a single institution meeting National Trauma Data Standard criteria from April 2015 to September 2019 were examined with regards to VTE chemoprophylaxis regimen and VTE incidence. Two groups of patients were identified based on VTE protocol-those who received enoxaparin 30 mg twice daily without routine anti-Xa levels ("pre") versus those who received enoxaparin 40 mg twice daily with dose titrated by serial anti-Xa levels ("post"). Univariate and multivariate analyses were performed to define statistically significant differences in VTE incidence between the two cohorts. RESULTS: There were 1698 patients within the "pre" group and 1406 patients within the "post" group. The two groups were essentially the same in terms of demographics and risk factors for bleeding or thrombosis. There was a statistically significant reduction in VTE rate (p = 0.01) and deep vein thrombosis rate (p = 0.01) but no significant reduction in pulmonary embolism rate (p = 0.21) after implementation of the anti-Xa titration protocol. Risk-adjusted Trauma Quality Improvement Program data showed an improvement in rate of symptomatic pulmonary embolism from fifth decile to first decile. CONCLUSION: A protocol titrating prophylactic enoxaparin dose based on anti-Xa levels reduced VTE rates. Implementation of this type of protocol requires diligence from the physician and pharmacist team. Further research will investigate the impact of protocol compliance and time to appropriate anti-Xa level on incidence of VTE. LEVEL OF EVIDENCE: Therapeutic/care management, Level IV.

Effectiveness and Community Acceptance of Extending Seasonal Malaria Chemoprevention to Children 5 to 14 Years of Age in Dangassa, Mali.

Seasonal malaria chemoprevention (SMC) was adopted in Mali in 2012 for preventing malaria in children younger than 5 years. Although this strategy has been highly effective in reducing childhood malaria, an uptick in malaria occurrence has occurred in children 5 to 15 years of age. This study aimed to investigate the feasibility of providing SMC to older children. A cohort of 350 children age 5 to 14 years were monitored during the 2019 transmission season in Dangassa, Mali. The intervention group received five monthly rounds of sulfadoxine-pyrimethamine plus amodiaquine, whereas the control group consisted of untreated children. Community acceptance for extending SMC was assessed during the final round. Logistic regression models were applied to compare the risk of Plasmodium falciparum malaria infection, anemia, and fever between the intervention and control groups. Kaplan-Meier survival analyses were used to compare the time to P. falciparum parasitemia infection between the groups. The community acceptance rate was 96.5% (139 of 144). Significant declines were observed in the prevalence of P. falciparum parasitemia (adjusted odds ratio, 0.22; 95% CI, 0.11-0.42) and anemia (adjusted odds ratio, 0.15; 95% CI, 0.07-0.28) in the intervention group compared with the control group. The cumulative incidence of P. falciparum infections was significantly greater (75.4%, 104 of 138) in the control group compared with the intervention group (40.7%, 61 of 143, P = 0.001). This study reveals that expanding SMC to older children is likely feasible, has high community acceptance, and is in reducing uncomplicated malaria and anemia in older children.

Surgical Management of Hereditary Breast Cancer.

The identification that breast cancer is hereditary was first described in the nineteenth century. With the identification of the BRCA1 and BRCA 2 breast/ovarian cancer susceptibility genes in the mid-1990s and the introduction of genetic testing, significant advancements have been made in tailoring surveillance, guiding decisions on medical or surgical risk reduction and cancer treatments for genetic variant carriers. This review discusses various medical and surgical management options for hereditary breast cancers.

Prevention of NAFLD-associated HCC: Role of lifestyle and chemoprevention.

In many countries worldwide, the burden of hepatocellular carcinoma (HCC) associated with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) is increasing. Preventive strategies are needed to counteract this trend. In this review, we provide an overview of the evidence on preventive strategies in NAFLD-associated HCC. We consider the impact of lifestyle factors such as weight loss, physical activity, smoking, dietary patterns and food items, including coffee and alcohol, on both HCC and NAFLD/NASH. Furthermore, evidence on chemopreventive treatments, including aspirin, antidiabetic treatments and statins is summarised. The role of adjuvant therapies for tertiary prevention of HCC is briefly reviewed.

A living WHO guideline on drugs to prevent covid-19.

CLINICAL QUESTION: What is the role of drugs in preventing covid-19? WHY DOES THIS MATTER?: There is widespread interest in whether drug interventions can be used for the prevention of covid-19, but there is uncertainty about which drugs, if any, are effective. The first version of this living guideline focuses on the evidence for hydroxychloroquine. Subsequent updates will cover other drugs being investigated for their role in the prevention of covid-19. RECOMMENDATION: The guideline development panel made a strong recommendation against the use of hydroxychloroquine for individuals who do not have covid-19 (high certainty). HOW THIS GUIDELINE WAS CREATED: This living guideline is from the World Health Organization (WHO) and provides up to date covid-19 guidance to inform policy and practice worldwide. Magic Evidence Ecosystem Foundation (MAGIC) provided methodological support. A living systematic review with network analysis informed the recommendations. An international guideline development panel of content experts, clinicians, patients, an ethicist and methodologists produced recommendations following standards for trustworthy guideline development using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. UNDERSTANDING THE NEW RECOMMENDATION: The linked systematic review and network meta-analysis (6 trials and 6059 participants) found that hydroxychloroquine had a small or no effect on mortality and admission to hospital (high certainty evidence). There was a small or no effect on laboratory confirmed SARS-CoV-2 infection (moderate certainty evidence) but probably increased adverse events leading to discontinuation (moderate certainty evidence). The panel judged that almost all people would not consider this drug worthwhile. In addition, the panel decided that contextual factors such as resources, feasibility, acceptability, and equity for countries and healthcare systems were unlikely to alter the recommendation. The panel considers that this drug is no longer a research priority and that resources should rather be oriented to evaluate other more promising drugs to prevent covid-19. UPDATES: This is a living guideline. New recommendations will be published in this article and signposted by update notices to this guideline. READERS NOTE: This is the first version of the living guideline for drugs to prevent covid-19. It complements the WHO living guideline on drugs to treat covid-19. When citing this article, please consider adding the update number and date of access for clarity.

Maximizing Impact: Can Interventions to Prevent Clinical Malaria Reduce Parasite Transmission?

Malaria interventions may reduce the burden of clinical malaria disease, the transmission of malaria parasites, or both. As malaria interventions are developed and evaluated, including those interventions primarily targeted at reducing disease, they may also impact parasite transmission. Achieving global malaria eradication will require optimizing the transmission-reducing potential of all available interventions. Herein, we discuss the relationship between malaria parasite transmission and disease, including mechanisms by which disease-targeting interventions might also impact parasite transmission. We then focus on three malaria interventions with strong evidence for reducing the burden of clinical malaria disease and examine their potential for also reducing malaria parasite transmission.

[Acquired angioedema due to C1-inhibitor deficiency: CREAK recommendations for diagnosis and treatment]. / Angiœdèmes par déficit acquis en C1-inhibiteur : recommandations du CREAK pour le diagnostic et la prise en charge.

Acquired angioedema with C1-inhibitor deficiency is a rare and peculiar entity belonging to the spectrum of bradykinin angioedemas. It usually occurs in subjects over 60 years old, and is mostly associated with a B-cell lymphoid hemopathy or a monoclonal gammopathy. The diagnosis relies on at least one angioedema episode, lasting more than 24 h, and on the decrease of functional C1-inhibitor. Low C1q is observed in 90% of patients, and an anti C1-inhibitor antibody is found in 50% of patients. The treatment of severe attacks relies on icatibant or C1-inhibitor perfusions. Long term prophylaxis in patients with frequent attacks requires treatment of the associated hemopathy if so. In case of idiopathic angioedema, tranexamic acid and danazol may be used, provided that there is-no thrombophilia; as well as rituximab as second-line treatment. Inhibitors of kallikrein still need to be evaluated in this therapeutic indication.

Optimal pre-emptive cytomegalovirus therapy threshold in a patient population with high prevalence of seropositive status.

INTRODUCTION: Preemptive therapy (PET) for cytomegalovirus (CMV) reactivation post allogeneic hematopoietic stem cell transplantation (SCT) was shown to decrease the incidence of CMV disease. However, the optimal PET threshold is elusive. PURPOSE OF THE STUDY: To examine the efficacy of PET initiation at a viral threshold of 1000 copies/mL (1560 IU/mL) in a patient population with high prevalence of CMV seropositive status. PATIENTS AND METHODS: A single center retrospective review of patients that underwent allogeneic SCT was done. RESULTS: A total of 195 allogeneic SCT recipients were included with median follow up of 18.1 (0.7-95.6) months. A total of 178 (91 %) of patients had a positive CMV PCR with median days to initial reactivation post SCT of 17 (1-1187); 129 patients had peak CMV titer < 1000 copies/mL (low titer) whereas the remaining 49 patients had a peak titer ≥ 1000 copies/mL (high titer). 120 (93 %) of patients with low titers cleared spontaneously with median time to clearance of 40 days (4-188). One patient in the high titer group developed CMV disease. At multivariable analysis; age at SCT HR 1.02 (1.004-1.04; 0.017), malignant vs. benign condition HR 9.4 (2.47-61; 0.0005) and cGVHD HR 0.37 (0.2-0.65; 0.0005) were significant for OS. CONCLUSIONS: CMV reactivation post SCT was very common in patients with high prevalence of seropositive status. A PET threshold of 1000 copies/mL (1560 IU/mL) appears desirable as it was associated with spontaneous clearance in over 90 % of patients while minimizing treatment related toxicity. Validation of these observations is warranted.

PPIs and Beyond: A Framework for Managing Anticoagulation-Related Gastrointestinal Bleeding in the Era of COVID-19.

Coronavirus disease of 2019 (COVID-19) can be associated with high morbidity and mortality; patients with severe clinical manifestations may develop significant coagulopathy as well as unexpected thromboembolic complications. In response, centers are increasingly treating selected patients with intermediate-dose prophylactic or even therapeutic dose anticoagulation in order to prevent potentially catastrophic thrombotic complications. With this changing practice, the authors suspect that inpatient gastrointestinal consult teams across the country will be frequently managing COVID-19 patients with gastrointestinal bleeding (GIB). In order to reduce potentially avoidable hospital readmissions for GIB while improving patient outcomes, it is imperative to appropriately risk-stratify patients prior to initiation of anticoagulation. In this review, we discuss how to appropriately identify high-risk patients for GIB and how to mitigate GIB risk with proton-pump inhibitor co-therapy, medication reconciliation, and Helicobacter pylori testing and treating in this complex and morbid population.

How to manage BRCA mutation carriers?

Inherited mutations in BRCA1 and BRCA2 genes increase the risk of development of cancer in organs especially in breast and ovary. Prevention and screening in BRCA mutation carriers are of high importance. Prophylactic surgeries are possible but are still insufficiently performed because they require surgical procedures in healthy patients. Guidelines for the management of BRCA mutations carriers must absolutely be part of the standard practice of all those involved in the management of these patients to increase the impact of the implementation of these preventive measures. There is no screening recommended for ovarian cancer. A risk-reducing bilateral salpingo-oophorectomy should be performed from age 35 to 40 years for BRCA1 mutation carriers and 40 to 45 years for BRCA2 mutation carriers. A screening for breast cancer should be performed annually from 30 years old by breast MRI and mammography. A risk-reducing bilateral mastectomy is recommended with nipple sparing mastectomy and immediate breast reconstruction from 30 years and before 40 years. A multidisciplinary care must be implemented for these patients with an important psychological support.

Barriers to Providing VTE Chemoprophylaxis to Hospitalized Patients: A Nursing-Focused Qualitative Evaluation.

BACKGROUND: Venous thromboembolism (VTE) is a serious medical condition that results in preventable morbidity and mortality. OBJECTIVES: The objective of this study was to identify nursing-related barriers to administration of VTE chemoprophylaxis to hospitalized patients. DESIGN: This was a qualitative study including nurses from five inpatient units at one hospital. METHODS: Observations were conducted on five units to gain insight into the process for administering chemoprophylaxis. Focus group interviews were conducted with nurses and were audio-recorded, transcribed verbatim, and analyzed using the Theoretical Domains Framework to identify barriers to providing VTE chemoprophylaxis. RESULTS: We conducted 14 focus group interviews with nurses from five inpatient units to assess nurses' perceptions of barriers to administration of VTE chemoprophylaxis. The barriers identified included nurses' misconceptions that ambulating patients did not require chemoprophylaxis, nurses' uncertainty when counseling patients on the importance of chemoprophylaxis, and a lack of comparative data for nurses regarding their specific refusal rates. CONCLUSIONS: Multiple factors act as barriers to patients receiving VTE chemoprophylaxis. These barriers are often modifiable targets for quality improvement. There is a need to focus on behavior changes that will remove or minimize barriers and equip nurses to ensure administration of VTE chemoprophylaxis by engaging patients in their care.

Practice patterns regarding post-discharge chemoprophylaxis for venous thromboembolism following bariatric surgery in the United States.

BACKGROUND: There is no consensus regarding the optimal venous thromboembolism (VTE) prevention strategy following bariatric surgery. Post-discharge chemoprophylaxis is frequently recommended for high-risk patients with little supporting data. OBJECTIVES: To define practices related to post-discharge chemoprophylaxis in the United States. SETTING: United States. METHODS: From the Truven Health MarketScan Research database we identified patients age 18 to 64 years undergoing laparoscopic sleeve gastrectomy and gastric bypass (2009-2015). Use of post-discharge low-molecular-weight or unfractionated heparin, vitamin K antagonists, Factor Xa inhibitors, or direct thrombin inhibitors was determined, as was the occurrence of VTE events from discharge to 90 days. Patients with VTE during the index admission were excluded to focus on chemoprophylaxis after discharge (versus treatment). Multivariate logistic regression was used to evaluate the association between VTE and anticoagulant usage. RESULTS: Of 105,246 patients, .8% with VTE prior to discharge were excluded. The study cohort was 78.1% female, with a median age of 44 years. Hypercoagulable disorder was present in .9%. Post-discharge chemoprophylaxis rates were 11.3% and varied from state to state (.5%-37.4%). VTE rates varied from state to state (.4%-2.6%). VTE after discharge occurred in 1.3%. On multivariate analysis, hypercoagulable disorder (odds ratio [OR] 14.0; 95% confidence interval [CI] 11.6-16.9, P < .001), age ≥60 years (OR 2.3; 95% CI 1.0-5.3; P = .047), and male sex (female OR .8; 95% CI .7-.9, P < .001) increased the risk for VTE. Post-discharge chemoprophylaxis was associated with increased VTE risk (OR 2.1; 95% CI 1.8-2.4; P < .001). CONCLUSIONS: Post-discharge chemoprophylaxis following laparoscopic bariatric surgery is employed in 11.3% of patients. Variation in VTE rates and prophylaxis strategies exist nationally.

G-CSF guideline adherence in Germany, an update with a retrospective and representative sample survey.

BACKGROUND: Current guidelines (GL) recommend neutropenia prophylaxis with G-CSF after chemotherapy (CTX) for patients with high (≥ 20%), or, if additional risk factors are present, intermediate (≥ 10-20%) risk of febrile neutropenia. The first sample survey in 2012 (NP1) showed lack of GL adherence. The aim of this second sample survey was to evaluate if GL adherence and implementation have improved. METHODS: The sample size represented 1.0% of the incidences of lung and 1.1% of breast cancer in Germany in 2010. Data of patients with a febrile neutropenia (FN) risk ≥ 10% who had received at least 2 cycles of chemotherapy between October 2014 and September 2015 was surveyed retrospectively. RESULTS: Data from 573 lung cancer (LC) and 801 breast cancer (BC) patients was collected from 109 hospitals and 83 oncology practices with 222 physicians participating. Compared with the NP1 survey, GL adherence increased in LC and FN high-risk (HR) chemotherapy from 15.4 to 47.8% (p < 0.001), and in FN intermediate-risk (IR) chemotherapy from 38.8 to 44.3% (p = 0.003). In BC and FN-HR chemotherapy, GL adherence was unchanged: 85.6% vs. 85.1% (p = 0.73) but increased in FN-IR from 49.3 to 57.8% (p < 0.001). In all IR CTX cycles, there are also no significant differences in GL adherence between the first (51.3%) and subsequent cycles (51.1%; p = 0.948). In LC patients treated in certified or comprehensive cancer centers, the GL adherence in FN-HR chemotherapy was 53.0% vs. 44.9% in other centers (p = 0.295); in FN-IR chemotherapy, it was 45.1% vs. 43.8% (p = 0.750). In BC with FN-HR chemotherapy, GL adherence in certified or comprehensive centers was 85.4% vs. 84.7% in other institutions (p = 0.869); in FN-IR chemotherapy, it was 60.2% vs. 55.0% (p = 0.139). GL adherence in FN-HR chemotherapy and in FN-IR chemotherapy differed between pulmonologists and hematologist-oncologists (FN-HR: 25.0% vs. 43.6%, p < 0.001; 38.1% vs. 48.6%, p < 0.001). Comparing gynecologists with hematologist-oncologists, GL adherence in FN-HR chemotherapy was 86.2% vs. 82.5%. In FN-IR chemotherapy, GL adherence by gynecologists and hematologist-oncologists was 58.6% and 55.6%, respectively (p = 0.288; p = 0.424). Classification and regression tree analysis split pulmonologists and other specialists, with the latter adhering more to GL (p < 0.001). Hematologist-oncologists and gynecologists with more than 2 years of professional training in medical cancer therapy adhered more closely to GL than others (68.7% vs. 46.2%, p < 0.001). Pulmonologists attending ≥ 2 national congresses annually adhered more to guidelines than other pulmonologists (44.8% vs. 24.3%, p < 0.001). CONCLUSIONS: Adherence to G-CSF GL in Germany has increased but is still insufficient. Certified and comprehensive cancer centers show a higher rate of GL implementation. In GL adherence, there is still a disparity between cancer types and between oncology treatment specialists.

Time to therapeutic range (TtTR), anticoagulation control, and cardiovascular events in vitamin K antagonists-naive patients with atrial fibrillation.

BACKGROUND: Vitamin K antagonists (VKAs) reduce cardiovascular events (CVEs) in atrial fibrillation (AF) when a time in therapeutic range (TiTR) >70% is achieved. Factors affecting the time to achieve the TR (TtTR) are unknown. METHODS: Prospective observational study including 1,406 nonvalvular AF patients starting VKAs followed for a mean of 31.3months (3,690 patient/year); TiTR, TtTR, and SAMe-TT2R2 score were calculated, and CVEs were recorded. RESULTS: Median TtTR was 8.0days (interquartile range 5.0-18.0). Patients with high TtTR (ie, >75th percentile) were more likely to be in AF than in sinus rhythm at entry (odds ratio [OR]: 1.423, P=.011). Median TiTR was 60.0%; low TiTR (below median) was associated with SAMe-TT2R2 score (OR: 1.175, P=.001), high TtTR (>75th percentile, OR: 1.357, P=.017), and number of international normalized ratio checks (OR: 0.998, P=.049). We recorded 113 CVEs (3.1%/y), with a higher rate seen in patients with TtTR >75th percentile compared to those below (log-rank test, P=.006). A multivariable Cox regression analysis showed that SAMe-TT2R2 score (hazard ratio [HR]: 1.331, P<.001), TtTR >75th percentile (HR: 1.505, P=.047), TiTR <70% (HR: 1.931, P=.004), number of international normalized ratio checks (HR: 0.988, P<.001), digoxin (HR: 1.855, P=.008), and proton-pump inhibitors (HR: 0.452, P<.001) were independently associated with CVEs. CONCLUSIONS: High TtTR is associated with poorer long-term quality of VKAs therapy. Patients with TtTR >18days or with high SAMe-TT2R2 score should be considered for treatment with non-vitamin K oral anticoagulants.

Preventive Chemotherapy in the Fight against Soil-Transmitted Helminthiasis: Achievements and Limitations.

Soil-transmitted helminths (STHs) are endemic in more than half of the world's countries. The World Health Organization has advocated targeted preventive chemotherapy (PC) to control STH infections by distributing albendazole or mebendazole to at-risk populations. While the overall impact and sustainability of this strategy is disputed, a decrease in moderate and heavy STH infections can be largely attributed to a scale-up of drug distribution. Two factors might jeopardise the success of PC programs. First, the benzimidazoles possess unsatisfactory efficacy against Trichuris trichiura infections. Second, increased drug distributions might trigger anthelmintic resistance. This review presents an overview of the burden of STH infections, the evolution of PC along with its success and challenges, recent estimates of the efficacy of recommended drugs, and alternative treatment options.

Mass chemoprophylaxis for control of outbreaks of meningococcal disease.

Although vaccination is the main strategy used to control meningococcal disease outbreaks, mass chemoprophylaxis has also been used as an immediate response to outbreaks, either to supplement vaccination or when vaccination is not possible. However, public health guidelines regarding the use of mass chemoprophylaxis for outbreak control vary by country, partly because the impact of mass chemoprophylaxis on the course of an individual outbreak is difficult to assess. We have reviewed data for the use of mass chemoprophylaxis during 33 outbreaks that occurred both in military populations and in communities and non-military organisations. In most outbreaks, no additional cases of meningococcal disease occurred after mass chemoprophylaxis, or cases occurred only in individuals who had not received prophylaxis. A delay of several weeks was common before cases occurred among prophylaxis recipients. Overall, the outbreak reports that we reviewed suggest that mass chemoprophylaxis might provide temporary protection to chemoprophylaxis recipients during outbreaks.