Mohammad Alfelali

Viral respiratory infections among Hajj pilgrims in 2013

Middle East respiratory syndrome coronavirus (MERS-CoV) has emerged in the Arabian Gulf region, with its epicentre in Saudi Arabia, the host of the ‘Hajj’ which is the world’s the largest mass gathering. Transmission of MERS-CoV at such an event could lead to its rapid worldwide dissemination. Therefore, we studied the frequency of viruses causing influenza-like illnesses (ILI) among participants in a randomised controlled trial at the Hajj 2013. We recruited 1038 pilgrims from Saudi Arabia, Australia and Qatar during the first day of Hajj and followed them closely for four days. A nasal swab was collected from each pilgrim who developed ILI. Respiratory viruses were detected using multiplex RT-PCR. ILI occurred in 112/1038 (11%) pilgrims. Their mean age was 35 years, 49 (44%) were male and 35 (31%) had received the influenza vaccine pre-Hajj. Forty two (38%) pilgrims had laboratory-confirmed viral infections; 28 (25%) rhinovirus, 5 (4%) influenza A, 2 (2%) adenovirus, 2 (2%) human coronavirus OC43/229E, 2 (2%) parainfluenza virus 3, 1 (1%) parainfluenza virus 1, and 2 (2%) dual infections. No MERS-CoV was detected in any sample. Rhinovirus was the commonest cause of ILI among Hajj pilgrims in 2013. Infection control and appropriate vaccination are necessary to prevent transmission of respiratory viruses at Hajj and other mass gatherings.

Changes in the prevalence of influenza-like illness and influenza vaccine uptake among Hajj pilgrims: A 10-year retrospective analysis of data.

BACKGROUND Influenza is an important health hazard among Hajj pilgrims. For the last ten years, pilgrims are being recommended to take influenza vaccine before attending Hajj. Vaccination coverage has increased in recent years, but whether there has been any change in the prevalence of influenza-like illness (ILI) is not known. In this analysis, we examined the changes in the rate of ILI against seasonal influenza vaccine uptake among Hajj pilgrims over the last decade. METHOD Data for this analysis is a synthesis of raw and published data from eleven Hajj seasons between 2005 and 214. For seven Hajj seasons the data were obtained from studies involving pilgrims of UK, Saudi Arabia and Australia; and for the remaining four Hajj seasons data were abstracted from published studies involving pilgrims from multiple countries. The data from both sources were synthesised to estimate the relative risk (RR) of acquisition of ILI in vaccinated versus unvaccinated pilgrims. RESULTS The pooled sample size of the included studies was 33,213 with most pilgrims being in the age band of 40-60 years (range: 0.5 to 95 years) and a male to female ratio of 1.6. The pilgrims originated, in order of frequency, from Iran, Australia, France, UK, Saudi Arabia, Indonesia, India, Algeria, Ivory Coast, Nigeria, Somalia, Turkey, Syria, Sierra Leone and USA. Except for one year (2008), data from individual years did not demonstrate a noticeable change in the rate of ILI against influenza vaccine coverage, however the combined data from all studies suggest that the prevalence of ILI decreased among Hajj pilgrims as the vaccine coverage increased over the last decade (RR 0.2, P<0.01). CONCLUSION This analysis suggests that influenza vaccine might be beneficial for Hajj pilgrims. However, controlled trials aided by molecular diagnostic tools could confirm whether such an effect is real or ostensible.

Australian Hajj pilgrims’ knowledge about MERS-CoV and other respiratory infections

Dear Editor,With the intense crowding in mass gatherings such as Hajj,there is a high risk of acquisition of airborne in-fections with the potential for its transmission in the pilgrims’country of origin(Memish Z A,et al.,2014).The risk of importing serious infections from Hajj has escalated since the emergence of the Middle East respiratory syndrome coronavirus(MERS-CoV)in Saudi Arabia and other neighbouring countries from September2012.Active surveillance of Hajj pilgrims in 2012 and 2013

Mandating influenza vaccine for Hajj pilgrims

www.thelancet.com/infection Vol 16 June 2016 633 The risk of acquisition and trans mission of respiratory tract infections including infl uenza is considerably enhanced among attendees of the Hajj pilgrimage. Infl uenza vaccine has been recommended by the Saudi Ministry of Health since 2005 for all pilgrims, particularly for those at increased risk of severe disease. The Saudi Ministry of Health is now seriously considering mandating infl uenza vaccine for all pilgrims, and the Saudi Thoracic Society has already urged consideration of a “strict vaccination strategy” for Hajj and Umrah visitors. Pooled estimates from observational studies indicate that infl uenza vaccine is eff ective against laboratory-proven infl uenza among Hajj pilgrims. A more stringent policy to ensure vaccination is justifi ed, but the challenges of such measures need to be carefully considered before making a compulsory recommendation for all Hajj pilgrims. First, the issue of vaccine availability for pilgrims before Hajj needs to be addressed. Hajj takes place on specifi c dates of the lunar calendar, which is 10–11 days shorter than the Gregorian calendar. Therefore, Hajj will occur in all seasons over the years, whereas infl uenza vaccine is available only during autumn and winter months of the southern and northern hemispheres. So, vaccine will not be available for some pilgrims if the Hajj dates correspond with spring or summer season of their countries. This has happened recently in France; none of the pilgrims from Marseille could receive infl uenza vaccine before the Hajj 2013 and 2014 since it was unavailable immediately before Hajj. A great number of pilgrims would thus be unable to meet a mandatory requirement. Second, to overcome the issue of unavailability due to seasonal shift, the Saudi Thoracic Society suggested that the southern hemisphere vaccine be used for pilgrims arriving from the northern hemisphere (evidence D, the committee’s expert opinion), but the logistics of such a policy are not outlined. It is unclear how a tailormade vaccine for a specifi c season and hemisphere could be made available for the population of the other hemisphere; since infl uenza is an RNA virus that mutates rapidly, the vaccine might be ineff ective, and whether the strategy is going to be benefi cial or sustainable should be formally explored. A detailed analysis of data on circulating infl uenza strains globally and at the Hajj found that strain mismatch is frequent, and there are instances of drift occurring between the vaccine strains and the circulating strains of the same hemisphere even before the end of the season. Therefore, the feasibility and usefulness of the Saudi Thoracic Society recommendation to use cross-hemisphere vaccine is uncertain for the moment. Third, although the vaccine uptake among overseas pilgrims has been improving, the uptake among domestic pilgrims has remained suboptimal. Except for the pandemic year when the vaccine uptake exceptionally rose to over 90%, infl uenza vaccine coverage among Saudi pilgrims has ranged between 0·7% and 10·5%, which is much lower when compared with the uptake in overseas pilgrims. Likewise, the uptake among Saudi health-care workers at Hajj is also low. The mandatory vaccination is most justifi ed for the high-risk domestic pilgrims and health-care workers during the winter season (when a vaccine is available). Fourth, there are examples of improving infl uenza vaccine uptake among Hajj pilgrims without mandating it. For instance, infl uenza vaccine uptake has reached and remained 80% or more among Australian Hajj pilgrims primarily with support and recommendation from Hajj tour group leaders. Misperceptions and not being aware of the vaccine availability are important reasons for not receiving vaccination (>75%) among Hajj visitors. Therefore, dispelling myths surrounding vaccinations would be an important step to improve vaccination uptake among Hajj pilgrims. Finally, from the example of meningococcal vaccine, it is apparent that a mandatory policy is not always practical. For instance, many domestic and some overseas pilgrims miss out meningococcal vaccine, although it is mandatory. Even the meningococcal vaccine uptake among domestic health-care workers in Haji is low. Also, mandatory polices for infl uenza vaccine for other populations (eg, health-care workers), have been controversial. In conclusion, infl uenza vaccine is highly commendable for Hajj attendees, including health-care workers, but a mandatory vaccination policy might not be practical. Continuous surveillance of infl uenza, and evaluation of the uptake and eff ectiveness of vaccination in Hajj pilgrims is required to inform a practically feasible policy. Mandating infl uenza vaccine for Hajj pilgrims

Mismatching between circulating strains and vaccine strains of influenza: Effect on Hajj pilgrims from both hemispheres

Abstract The trivalent seasonal influenza vaccine is expected to provide optimum protection if the vaccine strains match the circulating strains. The effect of worldwide mismatch between the vaccine strains and extant strains on travelers attending Hajj pilgrimage is not known. Annually 2-3 million Muslims coming from north and south hemispheres congregate at Hajj in Mecca, Saudi Arabia, where intense congestion amplifies the risk of respiratory infection up to eight fold. In order to estimate, to what extent mismatching increases the risk of vaccine failure in Hajj pilgrims, we have examined the global data on influenza epidemiology since 2003, in light of the available data from Hajj. These data demonstrate that globally mismatching between circulating and vaccine strains has occurred frequently over the last 12 years, and the mismatch seems to have affected the Hajj pilgrims, however, influenza virus characteristics were studied only in a limited number of Hajj seasons. When the vaccines are different, dual vaccination of travelers by vaccines for southern and northern hemispheres should be considered for Hajj pilgrims whenever logistically feasible. Consideration should also be given to the use of vaccines with broader coverage, i.e., quadrivalent, or higher immunogenicity. Continuous surveillance of influenza at Hajj is important.

Barriers of vaccinations against serious bacterial infections among Australian Hajj pilgrims

ABSTRACT Objectives: Vaccination against serious bacterial infections is recommended for Hajj pilgrims. Although the uptake of mandatory vaccines among Hajj pilgrims is acceptable, the uptake of other recommended vaccines remains suboptimal. In this study, we have explored the barriers to vaccination against serious bacterial infections among Australian Hajj pilgrims. Methods: Travellers aged 18 years and older planning to attend Hajj in the years 2014 and 2015 were surveyed at the immunization clinic of the Children’s Hospital at Westmead, Sydney, Australia. A questionnaire-based survey was conducted to explore pilgrims’ vaccination histories for their previous visits to Mecca, the reasons for non-receipt of vaccination, and to assess knowledge about the transmission of infections. Results: A total of 300 participants aged 18-76 (median 41) years completed the survey. Most (233 [77.7%]) were born outside Australia. Overall, 113 (37.7%) had performed pilgrimage in the past; 19 (16.8%) of them reported receiving pneumococcal vaccine and 16 (14.1%) diphtheria, tetanus and pertussis (DTP) vaccine. Lack of awareness about the availability of the vaccines was the main reason for non-receipt of pneumococcal and DTP vaccines (respectively 41.1% and 44.7%). Most pilgrims (266 [88.7%]) believed that travel vaccines are necessary before embarking on a journey; however, some expressed concerns about adverse reactions (156 [52.0%]), cost (114 [38.0%]), and permissibility of the vaccine according to their religion (6 [2.0%]). Respectively, 187 (62.3%), 145 (48.3%) and 86 (28.7%) respondents did not correctly know how meningococcal and pneumococcal diseases and pertussis transmit. Nevertheless, most (256 [85.3%]) indicated that they trust their family doctor for medical information and most (203 [67.7%]) preferred to receive the medical information in English. Conclusion: The uptake of recommended vaccines against serious bacterial infections among Australian Hajj pilgrims is low. Lack of awareness about the availability of vaccines, misperceptions surrounding the safety of vaccines and high cost are key barriers of uptake.

Infectious causes of sudden infant death syndrome

Investigators have long suspected the role of infection in sudden infant death syndrome (SIDS). Evidence of infectious associations with SIDS is accentuated through the presence of markers of infection and inflammation on autopsy of SIDS infants and isolates of some bacteria and viruses. Several observational studies have looked into the relation between seasonality and incidence of SIDS, which often showed a winter peak. These all may suggest an infectious aetiology of SIDS. In this review we have summarised the current literature on infectious aetiologies of SIDS by looking at viral, bacterial, genetic and environmental factors which are believed to be associated with SIDS.

Effect of Tdap when administered before, with or after the 13-valent pneumococcal conjugate vaccine (coadministered with the quadrivalent meningococcal conjugate vaccine) in adults: A randomised controlled trial

Sequential or co-administration of vaccines has potential to alter the immune response to any of the antigens. Existing literature suggests that prior immunisation of tetanus/diphtheria-containing vaccines can either enhance or suppress immune response to conjugate pneumococcal or meningococcal vaccines. We examined this interaction among adult Australian travellers before attending the Hajj pilgrimage 2014. We also investigated tolerability of these vaccines separately and concomitantly. We randomly assigned each participant to one of three vaccination schedules. Group A received adult tetanus, diphtheria and acellular pertussis vaccine (Tdap) 3-4weeks before receiving CRM197-conjugated 13-valent pneumococcal vaccine (PCV13) and CRM197-conjugated quadrivalent meningococcal vaccine (MCV4). Group B received all three vaccines on one day. Group C received PCV13 and MCV4 3-4weeks before Tdap. Blood samples collected at baseline, each vaccination visit and 3-4weeks after vaccination were tested using the pneumococcal opsonophagocytic assay (OPA) and by ELISA for diphtheria and tetanus antibodies. Funding for meningococcal serology was not available. Participants completed symptom diaries after each vaccination. A total of 111 participants aged 18-64 (median 40) years were recruited. No statistically significant difference was detected across the three groups in achieving OPA titre ⩾1:8 post vaccination. However, compared to other groups, Group A had a statistically significant lower number of subjects achieving ⩾4-fold rise in serotype 3, and also significantly lower geometric mean titres (GMTs) to six (of 13) pneumococcal serotypes (3, 5, 18C, 4, 19A and 9V). Group C (given prior PCV13 and MVC4) had statistically significant higher pre-Tdap geometric mean concentration (GMC) of anti-diphtheria IgG; however, there was no difference across the three groups following Tdap. Anti-tetanus IgG GMCs were similar across the groups before and after Tdap. No serious adverse events were reported. In conclusion, Tdap vaccination 3-4weeks before concomitant administration of PCV13 and MCV4 significantly reduced the antibody response to six of the 13 pneumococcal serotypes in adults. The trial is registered at the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12613000536763.

Uptake and effectiveness of facemask against respiratory infections at mass gatherings: a systematic review

Abstract Objectives The risk of acquisition and transmission of respiratory infections is high among attendees of mass gatherings (MGs). Currently used interventions have limitations yet the role of facemask in preventing those infections at MG has not been systematically reviewed. We have conducted a systematic review to synthesise evidence about the uptake and effectiveness of facemask against respiratory infections in MGs. Methods A comprehensive literature search was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines using major electronic databases such as, Medline, EMBASE, SCOPUS and CINAHL. Results Of 25 studies included, the pooled sample size was 12710 participants from 55 countries aged 11 to 89 years, 37% were female. The overall uptake of facemask ranged from 0.02% to 92.8% with an average of about 50%. Only 13 studies examined the effectiveness of facemask, and their pooled estimate revealed significant protectiveness against respiratory infections (relative risk [RR]=0.89, 95% CI: 0.84-0.94, p <0.01), but the study end points varied widely. Conclusion A modest proportion of attendees of MGs use facemask, the practice is more widespread among health care workers. Facemask use seems to be beneficial against certain respiratory infections at MGs but its effectiveness against specific infection remains unproven.

Effect of Tdap upon antibody response to meningococcal polysaccharide when administered before, with or after the quadrivalent meningococcal TT-conjugate vaccine (coadministered with the 13-valent pneumococcal CRM197-conjugate vaccine) in adult Hajj pilgrims: A randomised controlled trial

Hajj pilgrims are susceptible to several serious infections and are required to receive multiple vaccinations. Polysaccharide-protein conjugate vaccines contain carrier proteins such as tetanus toxoid (TT), diphtheria toxoid or a mutant of diphtheria toxoid (CRM197). These carrier proteins may interact with other conjugate or combination vaccines containing tetanus or diphtheria on concurrent or sequential administration. We examined the immune interaction of separate and concomitant administration of a tetanus/diphtheria/acellular pertussis (Tdap) vaccine with a TT-conjugated quadrivalent meningococcal vaccine (MCV4) (coadministered with 13-valent pneumococcal CRM197-conjugate vaccine [PCV13]) in adult Australian pilgrims before attending Hajj in 2015. We randomly assigned each participant to one of three vaccination schedules. Group 1 received Tdap 3-4 weeks before receiving MCV4 coadministered with PCV13. Group 2 received all three vaccines concomitantly. Group 3 received MCV4 and PCV13 3-4 weeks before Tdap. Blood samples were collected at baseline, at each vaccination visit and 3-4 weeks after vaccination and tested for response to meningococcal serogroups C, W and Y using a serum bactericidal antibody (rSBA) assay with baby rabbit complement, and to diphtheria and tetanus toxoid, measuring IgG antibodies by ELISA. Participants completed symptom diaries after each vaccination. A total of 166 participants aged 18-64 (median 42) years were recruited, of whom 160 completed the study. Compared to the other groups, Group 1 (given Tdap first) had significantly lower proportion of subjects achieving a ≥4-fold rise in rSBA for serogroup W. No difference was detected across the three groups in achieving protection threshold (rSBA ≥8 post vaccination) or SBA geometric mean titre (GMT) post vaccination. Group 3, which was given MCV4/PCV13 first, had high levels of antibody against diphtheria and tetanus than the other groups, when tested prior to receipt of Tdap; Only the anti-tetanus responses remained significantly higher after Tdap administration. No serious adverse events were reported. In conclusion, when multiple vaccination is required for Hajj pilgrims, administering Tdap concurrently with MCV4/PCV13 produces adequate immune responses, and avoids meningococcal immune interference, in the convenience of a single consultation. However, giving Tdap 3-4 weeks after MCV4/PCV13 has the advantage of an enhanced tetanus toxoid response. The trial is Trials Registry (ANZCTR): ACTRN12613000536763.