Mass gathering and globalization of respiratory pathogens during the 2013 Hajj

Every year, more than 10 million pilgrims arrive in the Kingdom of Saudi Arabia for the Hajj or Umrah. Crowding conditions lead to high rates of respiratory infections among the pilgrims, representing a significant cause of morbidity and a major cause of hospitalization. Pre- and post-Hajj nasal specimens were prospectively obtained from a paired cohort (692 pilgrims) and from nonpaired cohorts (514 arriving and 470 departing pilgrims) from 13 countries. The countries of residence included Africa (44.2%), Asia (40.2%), the United States (8.4%) and Europe (7.2%). Nasal specimens were tested for 34 respiratory pathogens using RT-PCR. A total of 80 512 PCRs were performed. The prevalence of viruses and bacteria increased, from 7.4% and 15.4% before the Hajj to 45.4% and 31.0% after the Hajj, respectively, due to the acquisition of rhinovirus, coronaviruses (229E, HKU1, OC43), influenza A H1N1, Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus. We did not identify Middle East respiratory coronavirus carriage. At arrival, the prevalence of several viruses was clearly dependent on the pilgrim's country of origin. After Hajj participation, these viruses were isolated among pilgrims from all countries, with few exceptions. No significant differences were observed between paired and nonpaired cohort results. Our results strongly suggest that, given the particularly crowded conditions during the rituals, an international mass gathering such as the Hajj may contribute to the globalization of respiratory pathogens after the cross-contamination of pilgrims harbouring pathogens that easily spread among participants. Influenza and pneumococcal vaccination, face mask use and hand hygiene should be considered in the context of the Hajj.

Biosignatures on Mars: What, Where, and How? Implications for the Search for Martian Life

The search for traces of life is one of the principal objectives of Mars exploration. Central to this objective is the concept of habitability, the set of conditions that allows the appearance of life and successful establishment of microorganisms in any one location. While environmental conditions may have been conducive to the appearance of life early in martian history, habitable conditions were always heterogeneous on a spatial scale and in a geological time frame. This "punctuated" scenario of habitability would have had important consequences for the evolution of martian life, as well as for the presence and preservation of traces of life at a specific landing site. We hypothesize that, given the lack of long-term, continuous habitability, if martian life developed, it was (and may still be) chemotrophic and anaerobic. Obtaining nutrition from the same kinds of sources as early terrestrial chemotrophic life and living in the same kinds of environments, the fossilized traces of the latter serve as useful proxies for understanding the potential distribution of martian chemotrophs and their fossilized traces. Thus, comparison with analog, anaerobic, volcanic terrestrial environments (Early Archean >3.5-3.33 Ga) shows that the fossil remains of chemotrophs in such environments were common, although sparsely distributed, except in the vicinity of hydrothermal activity where nutrients were readily available. Moreover, the traces of these kinds of microorganisms can be well preserved, provided that they are rapidly mineralized and that the sediments in which they occur are rapidly cemented. We evaluate the biogenicity of these signatures by comparing them to possible abiotic features. Finally, we discuss the implications of different scenarios for life on Mars for detection by in situ exploration, ranging from its non-appearance, through preserved traces of life, to the presence of living microorganisms.

KEY WORDS

Mars-Early Earth-Anaerobic chemotrophs-Biosignatures-Astrobiology missions to Mars.

Lack of nasal carriage of novel corona virus (HCoV-EMC) in French Hajj pilgrims returning from the Hajj 2012, despite a high rate of respiratory symptoms

A cohort of 154 French Hajj pilgrims participating in the 2012 Hajj were systematically sampled with nasal swabs prior to returning to France, and screened for the novel HCoV-EMC coronavirus by two real-time RT-PCR assays. Despite a high rate of respiratory symptoms (83.4%), including 41.0% influenza-like illness, no case of HCoV-EMC infection was detected. Despite the fact that zoonotic transmission was suspected in the first few cases, a recent family cluster in the Kingdom of Saudi Arabia suggests that the virus might show at least limited spread from person to person, which justifies continuing epidemiological surveillance.

A Hydrothermal-Sedimentary Context for the Origin of Life

Critical to the origin of life are the ingredients of life, of course, but also the physical and chemical conditions in which prebiotic chemical reactions can take place. These factors place constraints on the types of Hadean environment in which life could have emerged. Many locations, ranging from hydrothermal vents and pumice rafts, through volcanic-hosted splash pools to continental springs and rivers, have been proposed for the emergence of life on Earth, each with respective advantages and certain disadvantages. However, there is another, hitherto unrecognized environment that, on the Hadean Earth (4.5-4.0 Ga), would have been more important than any other in terms of spatial and temporal scale: the sedimentary layer between oceanic crust and seawater. Using as an example sediments from the 3.5-3.33 Ga Barberton Greenstone Belt, South Africa, analogous at least on a local scale to those of the Hadean eon, we document constant permeation of the porous, carbonaceous, and reactive sedimentary layer by hydrothermal fluids emanating from the crust. This partially UV-protected, subaqueous sedimentary environment, characterized by physical and chemical gradients, represented a widespread system of miniature chemical reactors in which the production and complexification of prebiotic molecules could have led to the origin of life. Key Words: Origin of life-Hadean environment-Mineral surface reactions-Hydrothermal fluids-Archean volcanic sediments. Astrobiology 18, 259-293.

Erythrocyte stages of Plasmodium falciparum exhibit a high nitric oxide synthase (NOS) activity and release an NOS-inducing soluble factor

Nitric oxide (NO), a highly diffusible cellular mediator involved in a wide range of biological effects, has been indicated as one of the cytotoxic agents released by leukocytes to counteract malaria infection. On the other hand, NO has been implicated as a mediator of the neuropathological symptoms of cerebral malaria. In such circumstances NO production has been thought to be induced in host tissues by host-derived cytokines. Here we provide evidence for the first time that human red blood cells infected by Plasmodium falciparum (IRBC) synthesize NO. The synthesis of NO (measured as citrulline and nitrate production) appeared to be very high in comparison with human endothelial cells; no citrulline and nitrate production was detectable in noninfected red blood cells. The NO synthase (NOS) activity was very high in the lysate of IRBC (while not measurable in that of normal red blood cells) and was inhibited in a dose-dependent way by three different NOS inhibitors (L-canavanine, NG-amino-L-arginine, and NG-nitro-L-arginine). NOS activity in P. falciparum IRBC is Ca++ independent, and the enzyme shows an apparent molecular mass < 100 kD, suggesting that the parasite expresses an isoform different from those found in mammalian cells. IRBC release a soluble factor able to induce NOS in human endothelial cells. Such NOS-inducing activity is not tissue specific, is time and dose dependent, requires de novo protein synthesis, and is probably associated with a thermolabile protein having a molecular mass > 100 kD. Our data suggest that an increased NO synthesis in P. falciparum malaria can be directly elicited by soluble factor(s) by the blood stages of the parasite, without necessarily requiring the intervention of host cytokines.

Measles among healthcare workers: a potential for nosocomial outbreaks

We report here 14 cases of measles among healthcare workers (HCWs) in Public Hospitals of Marseilles, France that occurred between April and November 2010. All cases but one were under 30 years of age. Following the identification of these cases, we checked the immune status among 154 HCWs who volunteered to take part in the study and showed that 93% and 88% were immune against measles and mumps respectively. HCWs non-immunised against measles were all under 30 years of age.

Infectious diseases among travellers and migrants in Europe, EuroTravNet 2010

To investigate trends in travel-associated morbidity with particular emphasis on emerging infections with the potential for introduction into Europe, diagnoses of 7,408 returning travellers presenting to 16 EuroTravNet sites in 2010 were compared with 2008 and 2009. A significant increase in reported Plasmodium falciparum malaria (n=393 (6% of all travel-related morbidity) vs. n=267 (4%) and 296 (5%); p<0.001), P. vivax malaria (n=53 (1%) vs. n=31 (0.5%) and 39 (1%); p=0.038) and dengue fever (n=327 (5%) vs. n=131 (2%) and 172 (2%); p<0.001) was observed. Giardia lamblia was identified in 16% of patients with acute diarrhoea, with no significant annual variation. The proportion of acute diarrhoea due to Campylobacter increased from 7% in 2008 to 12% in 2010 (p=0.002). We recorded 121 patients with pulmonary tuberculosis in 2010, a three-fold increase in the proportionate morbidity from 2008 to 2010. In 2010, 60 (0.8%) cases of chronic Chagas disease, 151 (2%) cases of schistosomiasis and 112 (2%) cases of cutaneous larva migrans were reported. Illness patterns in sentinel travellers, captured by EuroTravnet, continue to highlight the potential role of travellers in the emergence of infectious diseases of public health concern in Europe and the relevance of offering medical travel advice and enforcing specific and adequate prophylaxis.*

Clinical efficacy of chloroquine derivatives in COVID-19 infection: comparative meta-analysis between the big data and the real world

In the context of the current coronavirus disease 2019 (COVID-19) pandemic, we conducted a meta-analysis on the effects of chloroquine derivatives in patients, based on unpublished and published reports available publicly on the internet as of 27 May 2020. The keywords 'hydroxychloroquine', 'chloroquine', 'coronavirus', 'COVID-19' and 'SARS-Cov-2' were used in the PubMed, Google Scholar and Google search engines without any restrictions as to date or language. Twenty studies were identified involving 105 040 patients (19 270 treated patients) from nine countries (Brazil, China, France, Iran, Saudi Arabia, South Korea, Spain and the USA). Big data observational studies were associated with conflict of interest, lack of treatment dosage and duration, and absence of favourable outcome. Clinical studies were associated with favourable outcomes and details on therapy. Among clinical studies, three of four randomized controlled trials reported a significant favourable effect. Among clinical studies, a significant favourable summary effect was observed for duration of cough (OR 0.19, p 0.00003), duration of fever (OR 0.11, p 0.039), clinical cure (OR 0.21, p 0.0495), death (OR 0.32, p 4.1 × 10-6) and viral shedding (OR 0.43, p 0.031). A trend for a favourable effect was noted for the outcome 'death and/or intensive care unit transfer' (OR 0.29, p 0.069) with a point estimate remarkably similar to that observed for death (∼0.3). In conclusion, a meta-analysis of publicly available clinical reports demonstrates that chloroquine derivatives are effective to improve clinical and virological outcomes, but, more importantly, they reduce mortality by a factor of 3 in patients with COVID-19. Big data are lacking basic treatment definitions and are linked to conflict of interest. The retraction of the only big data study associated with a significantly deleterious effect the day after (June 5, 2020) the acceptance of the present work (June 4, 2020) confirms the relevance of this work.

Outbreaks associated to large open air festivals, including music festivals, 1980 to 2012

In the minds of many, large scale open air festivals have become associated with spring and summer, attracting many people, and in the case of music festivals, thousands of music fans. These festivals share the usual health risks associated with large mass gatherings, including transmission of communicable diseases and risk of outbreaks. Large scale open air festivals have however specific characteristics, including outdoor settings, on-site housing and food supply and the generally young age of the participants. Outbreaks at large scale open air festivals have been caused by Cryptosporium parvum, Campylobacter spp., Escherichia coli, Salmonella enterica, Shigella sonnei, Staphylococcus aureus, hepatitis A virus, influenza virus, measles virus, mumps virus and norovirus. Faecal-oral and respiratory transmissions of pathogens result from non-compliance with hygiene rules, inadequate sanitation and insufficient vaccination coverage. Sexual transmission of infectious diseases may also occur and is likely to be underestimated and underreported. Enhanced surveillance during and after festivals is essential. Preventive measures such as immunisations of participants and advice on-site and via social networks should be considered to reduce outbreaks at these large scale open air festivals.

Hajj pilgrims knowledge about Middle East respiratory syndrome coronavirus, August to September 2013

In preparation for Hajj 2013, 360 French pilgrims were interviewed regarding their knowledge about Middle East respiratory syndrome (MERS). Respondents were aged 20–85 years, male-female ratio was 1.05:1;64.7% were aware of the MERS situation in Saudi Arabia; 35.3% knew about the Saudi Ministry of Health recommendations for at-risk pilgrims to postpone participation in the 2013 Hajj. None of 179 at-risk individuals(49.9%) decided to cancel their Hajj participation even after advice during consultation.

Incidence of Hajj-associated febrile cough episodes among French pilgrims: a prospective cohort study on the influence of statin use and risk factors

A prospective epidemiological study was conducted to evaluate the incidence of febrile cough episodes among adult Muslims travelling from Marseille to Saudi Arabia during the Hajj pilgrimage and to assess if use of statin had an influence on this incidence. In total, 580 individuals were presented with a questionnaire. A significant proportion of individuals had chronic medical disorders, e.g. diabetes mellitus (132, 22.8%) and hypertension (147, 25.3%). Pilgrims had a low level of education and a low employment rate. Sixty (10.3%) were treated with statins for hypercholesterolemia. Four hundred and fourty-seven pilgrims were presented a questionnaire on returning home. A total of 74 travellers (16.6%) experienced fever during their stay in Saudi Arabia (67 attended a doctor) and 271 (60.6%) had cough (259 attended a doctor); 70 travellers with cough were febrile (25.9%). Seventy per cent of the travellers who suffered cough episodes developed their first symptoms within 3 days, suggesting a human to human transmission of the responsible pathogen, with short incubation time as evidenced by a bimodal distribution of cough in two peaks at a 24 h interval. None of demographical and socioeconomic characteristics, underlying diseases or vaccination against influenza significantly affected the occurrence of cough. Diabetes correlated with an increased risk of febrile cough (OR = 2.02 (1.05-3.89)) as well as unemployment (OR = 2.22 (0.91-5.53)). Use of statins had no significant influence on the occurrence of cough and/or fever during the pilgrimage. This result suggests that while treatment with a statin has been demonstrated to reduce the mortality from severe sepsis associated with respiratory tract infections, it probably does not play a role in the outcome of regular febrile cough episodes as observed in the cohort studied here.

Periodic infectivity of Plasmodium gametocytes to the vector. A review

Frank Hawking, in 1966 postulated that in synchronous malaria infections, the brief period of infectivity of gametocytes was timed to occur when the vector bites. Since this early work, numerous studies had contributed to confirm and explain this phenomenon with bird, rodent and primate Plasmodium. Data on the periodic production of gametocytes, the duration of their maturation, the effect of the schizogony on the infectivity and the circadian bioavailability of gametocytes provide some more informations on the periodic Plasmodium gametocyte infectivity to the vector. This paper is intended to be a review of contributions on the "Hawking phenomenon" and to summarize the principal causal hypotheses. The conclusion stresses the practical consequences for experimental studies and epidemiological surveys.

The spread of vaccine-preventable diseases by international travellers: a public-health concern

Vaccine-preventable diseases (VPDs) are costly at both the individual and societal levels. The most common VPDs recorded in travellers are enteric (typhoid or paratyphoid B) fever, acute viral hepatitis, influenza, varicella, measles, pertussis and bacterial meningitis. Travellers suffering from VPDs are frequently hospitalized, illustrating the point that VPDs are serious and expensive. Many travellers are not properly immunized before travel. In addition to individual consequences, VPDs can have public-health consequences if they are introduced or re-introduced by infected travellers returning to areas with susceptible populations. The international spread of poliomyelitis, Neisseria meningitidis serogroup W135 meningococcal infections, measles and influenza provides strong evidence of the role of international travel in the globalization of VPDs. The surveillance of the emergence, re-emergence or spread of VPDs is essential to adapt pre-travel advice and the responses to the VPD.

Mobility of Pb, Zn, Ba, As and Cd toward soil pore water and plants (willow and ryegrass) from a mine soil amended with biochar

Mine soils often contain metal(loid)s that may lead to serious environmental problems. Phytoremediation, consisting in covering the soil with specific plants with the possible addition of amendments, represents an interesting way of enhancing the quality of mine soils by retaining contaminants and reducing soil erosion. In order to study the effect of an assisted phytoremediation (with willow and ryegrass) on the properties of soil pore water (SPW), we investigated the impact of amendment with biochar (BC) combined with the planting of willow and ryegrass on the behavior of several metal(loid)s (Pb, Zn, Ba, As, and Cd) in a mine soil. Data on the physicochemical parameters and concentrations of the different metal(loid)s in both SPW and in plant tissues of willow and ryegrass highlight the importance of BC for SPW properties in terms of reductions in soluble concentrations of Pb and Zn, although there was no effect on the behavior of As and Cd. BC also increased soluble concentrations of Ba, probably related to ion release by the BC. By improving major ions available in mine soil, BC improved the lifetime of plants and enhanced their growth. Plant development did not appear to significantly affect the physicochemical parameters of SPW. Willow and ryegrass growing on soil with BC incorporated Cd and Ba into their tissues. The influence of plants on the behavior of metal(loid)s was noticeable only for ryegrass growing in soil with 2% BC, where it modified the behavior of Pb and Ba.

A comprehensive review of the Kumbh Mela: identifying risks for spread of infectious diseases

The Kumbh Mela in India is the largest mass gathering in the world which witnessed close to 100 million visitors in 2013. An event of this magnitude presents challenges. Increased population density, reduced hygienic conditions and exposure to environmental pollutants pave the way for easy transmission of pathogens. Due to the possibility of epidemics, the primary focus should be on identifying the potential risk factors and implementing appropriate preventive measures. The context of religion and psychology of the pilgrims is also closely associated with the evolution of the risk factors and so forms an important part of the discussion. We provide a brief background to the Kumbh Mela with a description of the existing and potential risk factors that require our attention.

Detection on four continents of dengue fever cases related to an ongoing outbreak in Luanda, Angola, March to May 2013

In April 2013, ten cases of dengue fever in travellers returning from Luanda, Angola, to five countries on four continents, were reported to the globally distributed GeoSentinel Surveillance network. Dengue virus serotype 1 was identified in two cases. The findings indicate that a major dengue outbreak is currently ongoing in Luanda. This report illustrates how cases from an emerging arboviral epidemic focus can spread internationally and highlights the risk of dissemination of a vector-borne disease into receptive areas

Rabies post-exposure prophylaxis in travellers returning from Bali, Indonesia, November 2008 to March 2010

Since 2008, when the outbreak of rabies in Bali began, 45 patients have attended GeoSentinel or EuroTravNet sites for rabies post-exposure prophylaxis (PEP), representing 12.6% of all travellers seen for PEP in all network clinics during the same time period. This suggests that Bali is emerging as a commonly visited destination among travellers presenting for rabies PEP. The data demonstrate that the majority of animal-related injuries in travellers returning from Bali are associated with exposure to monkeys, and not dog bites/scratches. The clinical implications of this are discussed.

Imported human African trypanosomiasis in Europe, 2005-2009

Physicians in Europe are likely to see more African trypanosomiasis cases because of the increasing popularity of travel to Africa. In this paper the literature on imported cases in Europe, since 2005 is reviewed. Because of the high mortality risk associated with acute Rhodesian trypanosomiasis, travellers should be informed about preventive measures and the early disease manifestations.

Imported Plasmodium vivax malaria in France: geographical origin and report of an atypical case acquired in Central or Western Africa

A total of 73 cases of Plasmodium vivax infections acquired in Western or Central Africa were diagnosed on microscopical criteria in French travellers from 1995 to 1998. We report a case of P. vivax infection in a non immune traveller confirmed by polymerase chain reaction and presenting an atypical P. ovale morphology. The infection was acquired in Western or Central Africa. These microscopical observations, together with the molecular evidence for P. vivax in Western and Central Africa suggest that P. vivax is transmitted in this area despite lacking the Duffy receptor in autochthonous population.

The adjustment of the schizogonic cycle of Plasmodium chabaudi chabaudi in the blood to the circadian rhythm of the host

Experiments were performed with P. chabaudi chabaudi to investigate the relationship between the development of the parasite and the circadian rhythm of the host. Blood was taken from a donor mouse at 10.00 hours, when it contained mainly young stages and inoculated to receptor mice, either immediately or after B hours at +4 degrees C. The inoculum was diluted in order to obtain a more or less extended prepatent period. Thus, by using successively the different mice, parasitemias could be followed during 12 days before the crisis. When parasitemias reached 1%, from day 1 (D1) to D7, depending on the dilution, the parasitic patterns were studied every 6 hours during 2 or 3 days. In mice inoculated at 10.00 hours the rhythm remained unmodified. In mice inoculated at 18.00 hours the infection was at first synchronous (from D1 to D4) but the schizogony occurred between 06.00 and 12.00 hours instead of midnight. From day 4 to day 7 the infection became asynchronous. At day 10 the normal rhythm was resumed and the schizogony occurred around midnight.

Evaluating the serological status of COVID-19 patients using an indirect immunofluorescent assay, France

An indirect in-house immunofluorescent assay was developed in order to assess the serological status of COVID-19 patients in Marseille, France. Performance of IFA was compared to a commercial ELISA IgG kit. We tested 888 RT-qPCR-confirmed COVID-19 patients (1302 serum samples) and 350 controls including 200 sera collected before the pandemic, 64 sera known to be associated with nonspecific serological interference, 36 sera from non-coronavirus pneumonia and 50 sera from patient with other common coronavirus to elicit false-positive serology. Incorporating an inactivated clinical SARS-CoV-2 isolate as the antigen, the specificity of the assay was measured as 100% for IgA titre ≥ 1:200, 98.6% for IgM titre ≥ 1:200 and 96.3% for IgG titre ≥ 1:100 after testing a series of negative controls. IFA presented substantial agreement (86%) with ELISA EUROIMMUN SARS-CoV-2 IgG kit (Cohen's Kappa = 0.61). The presence of antibodies was then measured at 3% before a 5-day evolution up to 47% after more than 15 days of evolution. We observed that the rates of seropositivity as well as the titre of specific antibodies were both significantly higher in patients with a poor clinical outcome than in patients with a favourable evolution. These data, which have to be integrated into the ongoing understanding of the immunological phase of the infection, suggest that detection anti-SARS-CoV-2 antibodies is useful as a marker associated with COVID-19 severity. The IFA assay reported here is useful for monitoring SARS-CoV-2 exposure at the individual and population levels.

Characterization and mobility of arsenic and heavy metals in soils polluted by the destruction of arsenic-containing shells from the Great War

Destruction of chemical munitions from World War I has caused extensive local top soil contamination by arsenic and heavy metals. The biogeochemical behavior of toxic elements is poorly documented in this type of environment. Four soils were sampled presenting different levels of contamination. The range of As concentrations in the samples was 1937-72,820mg/kg. Concentrations of Zn, Cu and Pb reached 90,190mg/kg, 9113mg/kg and 5777mg/kg, respectively. The high clay content of the subsoil and large amounts of charcoal from the use of firewood during the burning process constitute an ample reservoir of metals and As-binding materials. However, SEM-EDS observations showed different forms of association for metals and As. In metal-rich grains, several phases were identified: crystalline phases, where arsenate secondary minerals were detected, and an amorphous phase rich in Fe, Zn, Cu, and As. The secondary arsenate minerals, identified by XRD, were adamite and olivenite (zinc and copper arsenates, respectively) and two pharmacosiderites. The amorphous material was the principal carrier of As and metals in the central part of the site. This singular mineral assemblage probably resulted from the heat treatment of arsenic-containing shells. Microbial characterization included total cell counts, respiration, and determination of As(III)-oxidizing activities. Results showed the presence of microorganisms actively contributing to metabolism of carbon and arsenic, even in the most polluted soil, thereby influencing the fate of bioavailable As on the site. However, the mobility of As correlated mainly with the availability of iron sinks.

Viruses Occur Incorporated in Biogenic High-Mg Calcite from Hypersaline Microbial Mats

Using three different microscopy techniques (epifluorescence, electronic and atomic force microscopy), we showed that high-Mg calcite grains in calcifying microbial mats from the hypersaline lake "La Salada de Chiprana", Spain, contain viruses with a diameter of 50-80 nm. Energy-dispersive X-ray spectrometer analysis revealed that they contain nitrogen and phosphorus in a molar ratio of ~9, which is typical for viruses. Nucleic acid staining revealed that they contain DNA or RNA. As characteristic for hypersaline environments, the concentrations of free and attached viruses were high (>10(10) viruses per g of mat). In addition, we showed that acid treatment (dissolution of calcite) resulted in release of viruses into suspension and estimated that there were ~15 × 10(9) viruses per g of calcite. We suggest that virus-mineral interactions are one of the possible ways for the formation of nano-sized structures often described as "nanobacteria" and that viruses may play a role in initiating calcification.