Mass Antibiotic Prophylaxis Research Articles

1429. Meningococcal Disease Outbreak in a Refugee Reception Identification Center in Greece and Administration of Mass Antibiotic Prophylaxis

BackgroundAn increased likelihood of transmission of communicable diseases such as invasive meningococcal disease (IMD) exists in refugee camps. Herein, we describe an outbreak investigation of 5 IMD cases among immigrants in Greece.MethodsEpidemiological, clinical and laboratory data (culture and molecular identification) as well as the public health management concerning an outbreak of meningococcal disease in a refugee Reception Identification Center (RIC), are described.ResultsDuring the period 17th January - 17th February 2020, five cases of IMD in refugees were reported to the National Public Health Organization (NPHO). Four cases were from Afghanistan and resided in the RIC of Lesvos Island; two females aged 2 yo and 21 yo and two males 13 yo and 6 yo. The fifth case, a 4 month old male of Syrian nationality, exhibited symptoms after moving to an inland accommodation center (AC) from Lesvos RIC, on December 2019. Four of the cases presented with meningitis and septicaemia. All cases recovered and had no common exposure other than shared geographic space. Neisseria meningitidis was identified by molecular typing (mPCR, PorA, MLST, WGS) in all cases at the National Meningitis Reference Laboratory; 3/5 cases were identified as MenB, porA 7-2,4, and ST-3129 (new clone) while 2/5 (21 yo female, 13 yo male) as MenY, porA: 5.2, ST-22cc. To prevent secondary cases, antimicrobial chemoprophylaxis via Directly Observed Therapy (DOT) was administered to 4.024 Afgan close contacts (26.7% of the total Afgan population). MenACWY and MenB vaccination was recommended in response to outbreak among persons aged < 20 years old. No new IMD case occurred in the RIC during a follow-up period of 4 months.ConclusionThe detection of a new clone in Greece of Chinese and Taiwanese origin through migrants, further underlines the need of enhanced surveillance for early detection, molecular typing, immediate intervention with antibiotic prophylaxis and/or supplemental vaccination in order to prevent IMD in refugee camps.Disclosures All Authors: No reported disclosures

Adverse events following mass antibiotic prophylaxis during a Group A Streptococcus outbreak in the Canadian Forces Leadership and Recruit School

Adverse events following mass antibiotic prophylaxis during a Group A Streptococcus outbreak in the Canadian Forces Leadership and Recruit School

Adverse events following mass antibiotic prophylaxis during a Group A Streptococcus outbreak in the Canadian Forces Leadership and Recruit School.

Between December 2016 and March 2018, two outbreaks of Group A Streptococcus (GAS) infection occurred at the Canadian Forces Leadership and Recruit School. A voluntary mass antibiotic prophylaxis (MAP) program was implemented in March 2018, to interrupt an ongoing GAS outbreak, and to prevent future outbreaks. Instructors and recruits were offered a one-time intramuscular injection of 1.2 million units penicillin G benzathine (PGB). Individuals with a penicillin allergy were offered azithromycin; 500 mg orally once weekly for four consecutive weeks. Instructors and recruits were also asked to complete a voluntary and anonymous survey one week after receipt of MAP, to detect MAP-related adverse events. MAP was offered to 2,749 individuals; 2,707 of whom agreed to receive it (98.5% uptake). The majority of personnel experienced adverse events in the days following MAP; 92.3% of personnel who received PGB reported localized pain at the injection site, and 70.2% of personnel who received azithromycin reported gastrointestinal symptoms. However, only five cases of serious adverse events were reported, and less than 1% of recruits could not complete their basic military training course because of MAP-related adverse events. The MAP program implemented in March 2018 was the first of its kind in the Canadian Armed Forces, and the largest single use of PGB in a defined group in Canada. It resulted in very few serious adverse events and with minimal impact on military recruits' successful completion of recruit training.

Three sequential outbreaks of Group A Streptococcus over a two-year period at the Canadian Forces Leadership and Recruit School, St. Jean Garrison, Québec.

Since December 2016, the basic military training (BMT) facility for the Canadian Armed Forces (CAF) has experienced repeated outbreaks of Group A Streptococcus (GAS). In 2018, a voluntary mass antibiotic prophylaxis (MAP) program was implemented to interrupt GAS transmission among recruits. The objective of this study was to describe the epidemiology of three GAS outbreaks and a period of increased pharyngitis infections at the CAF BMT facility in Québec over a two-year span, and to detail the prevention and control measures implemented to mitigate the risk to recruit health. Descriptive data were collected on invasive and severe GAS cases along with laboratory data including genotyping of throat swabs from recruits presenting with pharyngitis. A laboratory-based acute respiratory infection surveillance system was used to aid in monitoring and decision-making. Close contacts of recruits were assessed for asymptomatic GAS carriage and MAP adverse events surveillance was conducted. Three distinct GAS outbreaks occurred at the Canadian Forces Leadership and Recruit School totaling eight invasive (iGAS) and 13 severe (sGAS) cases over two years. All iGAS/sGAS cases, apart from one instructor, were among recruits. The predominant strain in all three outbreaks was type emm6.4. A total of 11,293 recruits received MAP (penicillin G benzathine or azithromycin) between March 7, 2018 and November 18, 2019. There were eight reported serious adverse events related to penicillin administration. The CAF BMT facility experienced three GAS outbreaks over the course of two years, and despite the use of enhanced hygiene measures, only MAP has been effective in quelling these outbreaks.

Adverse events following mass antibiotic prophylaxis during a Group A Streptococcus outbreak in the Canadian Forces Leadership and Recruit School

Adverse events following mass antibiotic prophylaxis during a Group A Streptococcus outbreak in the Canadian Forces Leadership and Recruit School

Control measures for invasive group A streptococci (iGAS) outbreaks in care homes

The incidence of invasive group A streptococcal infections (iGAS) is increasing in Europe, with a particularly high morbidity and mortality in the elderly. Control of outbreaks in care homes is therefore important; but is unclear how best to manage these incidents. We attempted to identify which control measures are most likely to be effective. We undertook literature searches using PubMed and Google Scholar and contacted colleagues in Health Protection Units in England for unpublished outbreaks. We identified 31 outbreaks; of which 20 had sufficient detail for further analysis. Overall carriage rates of GAS in care home residents identified in outbreak investigations were 4.7%, and in staff 3.2%. In 8 outbreaks mass antibiotic prophylaxis was offered, in 9 selective prophylaxis only and in 3 none at all. Surveillance swabbing had limited influence on decisions regarding prophylaxis. A few papers mentioned the role of environmental contamination and the risk from an affected roommate. Pooling of results from these outbreaks failed to suggest any clear advantage to either a selective or mass antibiotic prophylaxis strategy in controlling spread. Systematic investigation and data collection from future outbreaks could be of benefit in informing future policy.

Mass antibiotic treatment to stop an outbreak of meningococcal disease: a molecular analysis

The occurrence of three cases of meningococcal disease among children in a small community, two of whom attended the same day-care centre, prompted a programme of mass antibiotic prophylaxis. Nasopharyngeal and throat swabs were obtained on three occasions from all children registered at the day-care centre. Serogroup B Neisseria meningitidis was isolated from 13 of 61 children before prophylaxis, from three children after 2 weeks, and from 19 children after 3 months. Repetitive extragenic palindromic PCR analysis identified several meningococcal strains before treatment, one of which became predominant after 3 months. Mass antibiotic prophylaxis initially suppressed meningococcal carriage, but the carriage rate subsequently rebounded.

A new model for prenatal brain damage. I. GABAA receptor activation induces cell death in developing rat hippocampus.

Protocols for mass antibiotic prophylaxis against anthrax were under development in New York City beginning in early 1999. This groundwork allowed the city’s Department of Health to rapidly respond in 2001 to six situations in which cases were identified or anthrax spores were found. The key aspects of planning and lessons learned from each of these mass prophylaxis operations are reviewed. Antibiotic distribution was facilitated by limiting medical histories to issues relevant to prescribing prophylactic antibiotic therapy, formatting medical records to facilitate rapid decision making, and separating each component activity into discrete work stations. Successful implementation of mass prophylaxis operations was characterized by clarity of mission and eligibility criteria, well-defined lines of authority and responsibilities, effective communication, collaboration among city agencies (including law enforcement), and coordination of staffing and supplies. This model can be adapted for future planning needs including possible attacks with other bioterrorism agents, such as smallpox.

Genetic analysis of capsular status of meningococcal carrier isolates.

The meningococcal capsule is the primary virulence factor with systemic isolates requiring full expression of the capsule but with capability to down-regulate the capsule in order to invade. The meningococcal capsular operon is composed of a number of genes that are involved in capsular synthesis and transport. Differences in capsular synthesis genes may allow discrimination between meningococcal serogroups whereas absence of genes for either synthesis or transport imply that the meningococcus is unencapsulated. Although mechanisms such as slipped-strand mispairing and acquisition of insertion sequences have been demonstrated to be involved in regulation of capsular expression, few studies have addressed the mechanisms of capsular expression in carrier isolates. Following a community-based intervention programme for an outbreak of meningococcal disease, we collected meningococcal carrier isolates from the intervention area and control areas. We undertook genetic analysis of the capsular operon and the mechanisms of capsular regulation, together with an investigation of the potential of capsular genes to identify the genogroup of non-serogroupable isolates. Use of the siaD gene allowed the discrimination of 30/89 (34%) non-serogroupable isolates into B, C, W135 and Y with a siaA gene PCR permitting the characterization of a further 6 isolates whose capsules contained sialic acid. Slipped-strand mispairing was evident in only 4 of 13 genogroupable B isolates and the insertion sequence IS1301 was found in 2 of 36 siaA-positive isolates. Of 51 non-genogroupable isolates 25 (49%) were shown to be ctrA negative. There was a higher percentage of ctrA-positive isolates (P<0.001) amongst meningococcal strains obtained from those sampled in non-intervention schools than those sampled at intervention schools. The ctrA-negative isolates warrant further investigation of their genotypic organization since such avirulent strains may be important in conferring natural protection against invasive disease. We found that after mass antibiotic prophylaxis, recolonization occurs preferentially with non-pathogenic meningococcal strains. This as implications for assessment of the benefits of mass antibiotic and vaccination programmes for outbreak control. Previously expressed concerns of increased risk due to removal of protective ora may have been overstated.

Failure of mass antibiotic prophylaxis to control a prolonged outbreak of meningococcal disease in an Israeli village.

In January 1994 mass antibiotic prophylaxis was undertaken in the contiguous villages of Deir el-Asad and B'ine in northern Israel (combined population of 11600) in response to a prolonged outbreak of serogroup B meningococcal infection with an overall annual rate of 37.4 cases of infection per 100000 residents. The average case fatality rate in the villages was 23% compared with 11% in Israel during the same period. Neisseria meningitidis group B was identified in 9 of 13 (69%) cases. Seven of these were subtype P1.7,16. The persistence of the outbreak with its accompanying public reaction prompted the establishment of an intervention programme that included antibiotic prophylaxis for the whole community with monitoring for pharyngeal carriage of meningococci in a stratified sample of the population. The objectives were to achieve a reduction of carriage of the outbreak strain and to reduce morbidity and mortality. A total of 1036 pharyngeal swabs were taken 1 day before and 6 weeks after treatment. Antibiotic prophylaxis was administered in one dose: children under 5-years-old received ceftriaxone i.m.; all others received oral ciprofloxacin. Overall, 96% of the population received treatment. The carriage rate was 8.3% prior to treatment (three serogroup B:14:P1.7,16), and 1.3% afterwards (one serogroup B:14:P1.7,16). The intervention failed to eradicate carriage of the putative outbreak strain, or to reduce the incidence and fatality rates in the villages. The outbreak finally terminated in late 1996. Public health professionals should bear this experience in mind when faced with prolonged, localized, nonexplosive outbreaks of meningococcal disease associated with low carriage rates of the outbreak strain.