Updated estimation of cutaneous leishmaniasis incubation period in French Guiana.

BACKGROUND: The cutaneous leishmaniasis (CL) incubation period (IP) is defined as the time between parasite inoculation by sandfly bite and the onset of the first CL lesion. IP distribution is difficult to assess for CL because the date of exposure to an infectious bite cannot be accurately determined in endemic areas. IP current estimates for CL range from 14 days to several months with a median around 30-60 days, as established by a few previous studies in both New and Old Worlds. METHODOLOGY: We estimated CL incubation period distribution using time-to-event models adapted to interval-censored data based on declared date of travels from symptomatic military personnel living in non-endemic areas that were exposed during their short stays in French Guiana (FG) between January 2001 and December 2021. PRINCIPAL FINDINGS: A total of 180 patients were included, of which 176 were men (97.8%), with a median age of 26 years. When recorded, the parasite species was always Leishmania guyanensis (31/180, 17.2%). The main periods of CL diagnosis spread from November to January (84/180, 46.7%) and over March-April (54/180, 30.0%). The median IP was estimated at 26.2 days (95% Credible Level, 23.8-28.7 days) using a Bayesian accelerated failure-time regression model. Estimated IP did not exceed 62.1 days (95% CI, 56-69.8 days) in 95% of cases (95th percentile). Age, gender, lesion number, lesion evolution and infection date did not significantly modify the IP. However, disseminated CL was significantly associated with a 2.8-fold shortening of IP. CONCLUSIONS: This work suggests that the CL IP distribution in French Guiana is shorter and more restricted than anticipated. As the incidence of CL in FG usually peaks in January and March, these findings suggest that patients are contaminated at the start of the rainy season.

Chikungunya Outbreak in Country with Multiple Vectorborne Diseases, Djibouti, 2019-2020.

During 2019-2020, a chikungunya outbreak occurred in Djibouti City, Djibouti, while dengue virus and malaria parasites were cocirculating. We used blotting paper to detect arbovirus emergence and confirm that it is a robust method for detecting and monitoring arbovirus outbreaks remotely.

A summary of cryptosporidiosis outbreaks reported in France and overseas departments, 2017-2020.

Cryptosporidium is a known foodborne pathogen, ranked fifth out of 24 among foodborne parasites in terms of importance and a cause of many cryptosporidiosis outbreaks worldwide. In France, very few outbreaks were reported before 2017, and data recently obtained by the Expert Laboratory of the Cryptosporidiosis National Reference Center (CNR-LE-Cryptosporidiosis) have shown that outbreaks are in fact common and frequently underreported. In this work, we aim to report the characteristics of outbreaks detected in France during the period 2017-2020 and present a summary of investigations carried out by the CNR-LE-Cryptosporidiosis. During the study period, there were eleven cryptosporidiosis outbreaks, including three with no identified origin. Among the eight identified outbreaks: six were due to water contamination (five tap water and one recreational water), one was due to direct contact with infected calves, and one was due to consumption of contaminated curd cheese. Among these outbreaks, five of them exceeded one hundred cases. Recent results obtained by the CNR-LE-Cryptosporidiosis revealed the multiannual occurrence of Cryptosporidium outbreaks in France. Waterborne outbreaks were more frequently detected, while foodborne outbreaks which are more difficult to detect were likely underreported.

Human Q Fever on the Guiana Shield and Brazil: Recent Findings and Remaining Questions.

PURPOSE OF REVIEW: In this review, we report on the state of knowledge about human Q fever in Brazil and on the Guiana Shield, an Amazonian region located in northeastern South America. There is a contrast between French Guiana, where the incidence of this disease is the highest in the world, and other countries where this disease is practically non-existent. RECENT FINDINGS: Recent findings are essentially in French Guiana where a unique strain MST17 has been identified; it is probably more virulent than those usually found with a particularly marked pulmonary tropism, a mysterious animal reservoir, a geographical distribution that raises questions. SUMMARY: Q fever is a bacterial zoonosis due to Coxiella burnetii that has been reported worldwide. On the Guiana Shield, a region mostly covered by Amazonian forest, which encompasses the Venezuelan State of Bolivar, Guyana, Suriname, French Guiana, and the Brazilian State of Amapá, the situation is very heterogeneous. While French Guiana is the region reporting the highest incidence of this disease in the world, with a single infecting clone (MST 117) and a unique epidemiological cycle, it has hardly ever been reported in other countries in the region. This absence of cases raises many questions and is probably due to massive under-diagnosis. Studies should estimate comprehensively the true burden of this disease in the region.

Role of Anopheles stephensi Mosquitoes in Malaria Outbreak, Djibouti, 2019.

Anopheles stephensi mosquitoes share urban breeding sites with Aedes aegypti and Culex quinquefasciatus mosquitoes in the Republic of Djibouti. We present evidence that A. stephensi mosquitoes might be responsible for an increase in malaria incidence in this country. We also document resistance of Plasmodium falciparum to dihydroartemisinin/piperaquine.

Lessons learned from the investigation of a COVID-19 cluster in Creil, France: effectiveness of targeting symptomatic cases and conducting contact tracing around them.

BACKGROUND: This study presents the methods and results of the investigation into a SARS-CoV-2 outbreak in a professional community. Due to the limited testing capacity available in France at the time, we elaborated a testing strategy according to pre-test probability. METHODS: The investigation design combined active case finding and contact tracing around each confirmed case with testing of at-risk contact persons who had any evocative symptoms (n = 88). One month later, we performed serology testing to test and screen symptomatic and asymptomatic cases again (n = 79). RESULTS: Twenty-four patients were confirmed (14 with RT-PCR and 10 with serology). The attack rate was 29% (24/83). Median age was 40 (24 to 59), and the sex ratio was 15/12. Only three cases were asymptomatic (= no symptoms at all, 13%, 95% CI, 3-32). Nineteen symptomatic cases (79%, 95% CI, 63-95) presented a respiratory infection, two of which were severe. All the RT-PCR confirmed cases acquired protective antibodies. Median incubation was 4 days (from 1 to 13 days), and the median serial interval was 3 days (0 to 15). We identified pre-symptomatic transmission in 40% of this cluster, but no transmission from asymptomatic to symptomatic cases. CONCLUSION: We report the effective use of targeted testing according to pre-test probability, specifically prioritizing symptomatic COVID-19 diagnosis and contact tracing. The asymptomatic rate raises questions about the real role of asymptomatic infected people in transmission. Conversely, pre-symptomatic contamination occurred frequently in this cluster, highlighting the need to identify, test, and quarantine asymptomatic at-risk contact persons (= contact tracing). The local lockdown imposed helped reduce transmission during the investigation period.

Acquisition of multidrug-resistant bacteria and encoding genes among French pilgrims during the 2017 and 2018 Hajj.

The objective of this study is to determine the acquisition of multidrug-resistant (MDR) bacteria and antibiotic resistance-encoding genes by French Hajj pilgrims and associated risk factors. Pilgrims traveling during the 2017 and 2018 Hajj were recruited. All pilgrims underwent two successive systematic nasopharyngeal and rectal swabs, pre- and post-Hajj. Specific culture media were used to screen for MDR bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant bacteria, and extended spectrum beta-lactamase producing Enterobacteriaceae (ESBL-E). qPCR was used to identify antibiotic resistance-encoding genes from cultured isolates. Direct screening of genes encoding for colistin resistance (mcr-1, 2, 3, 4, 5, and 8) from nasopharyngeal and rectal swabs was performed using qPCR, and positive qPCR results were simultaneously tested by sequencing. There were 268 pilgrims included. The percentage of pilgrims acquiring MDR bacteria during the Hajj was 19.4%. A total of 81 strains were isolated (1 carbapenem-resistant Acinetobacter baumannii, 12 MRSA, and 68 ESBL-E). ESBL-E strains were found in rectal samples of 6.0% pilgrims pre-Hajj and of 16.4% pilgrims post-Hajj. Only 0.4% pilgrims were positive for CARB post-Hajj and 1.9% carried nasal MRSA pre- and post-Hajj. In addition, 23 (8.6%) post-Hajj rectal swabs were positive for mcr genes (19 mcr-1 gene and 4 mcr-4 gene). No significant association was found between co-factors and acquisition of MDR bacteria or mcr genes. MDR bacteria and genes are acquired by pilgrims during the Hajj mass gathering. Rationalization of antibiotic consumption and implementation of measures to prevent transmission of bacteria among pilgrims during the event are of paramount importance.

Gastrointestinal symptoms and the acquisition of enteric pathogens in Hajj pilgrims: a 3-year prospective cohort study.

The acquisition of enteric pathogens and risk factors for Hajj-associated diarrhea in Hajj pilgrims is poorly documented. Pilgrims from Marseille participating in the Hajj in 2016-2018 underwent successive systematic rectal swabbing before and after their travel. Carriage of the main enteric pathogens was assessed by real-time PCR. Baseline demographics, adherence to individual preventive measures, gastrointestinal symptoms, and treatments were recorded. A total of 376 pilgrims were included. The median age was 62.0 years. During the Hajj, 18.6% presented at least one gastrointestinal symptom, 13.8% had diarrhea, and 36.4% had acquired at least one enteric pathogen. Enteropathogenic Escherichia coli (EPEC) and Enteroaggregative E. coli (EAEC) were the pathogens most frequently acquired by pilgrims (17.6% and 14.4%, respectively). Being female was associated with increased frequency of gastrointestinal symptoms during the pilgrimage (aOR = 2.38, p = 0.004). Enterohemorrhagic Escherichia coli (EHEC) acquisition was associated with a four-fold higher risk of reporting at least one gastrointestinal symptom and diarrhea (aOR = 3.68 and p = 0.01 and aOR = 3.96 and p = 0.01, respectively). Pilgrims who suffered from diarrhea were more likely to wash their hands more often (aOR = 2.07, p = 0.03) and to be either overweight (aOR = 2.71, p = 0.03) or obese (aOR = 2.51, p = 0.05). Enteric bacteria such as E. coli that are frequently associated with traveler's diarrhea due to the consumption of contaminated food and drink were frequently found in pilgrims. Respecting strict measures regarding food and water quality during the Hajj and adherence to preventive measures such as good personal hygiene and environmental management will help reduce the burden of gastrointestinal infections at the event.

The dynamics and interactions of respiratory pathogen carriage among French pilgrims during the 2018 Hajj.

We conducted this study to describe the dynamics of the acquisition of respiratory pathogens, their potential interactions and risk factors for possible lower respiratory tract infection symptoms (LRTI) among French pilgrims during the 2018 Hajj. Each participant underwent four successive systematic nasopharyngeal swabs before and during their stay in Saudi Arabia. Carriage of the main respiratory pathogens was assessed by PCR. 121 pilgrims were included and 93.4% reported respiratory symptoms during the study period. The acquisition of rhinovirus, coronaviruses and Staphylococcus aureus occurred soon after arrival in Saudi Arabia and rates decreased gradually after days 5 and 6. In contrast, Streptococcus pneumoniae and Klebsiella pneumoniae carriage increased progressively until the end of the stay in Saudi Arabia. Haemophilus influenzae and Moraxella catarrhalis carriage increased starting around days 12 and 13, following an initial clearance. Influenza viruses were rarely isolated. We observed an independent positive mutual association between S. aureus and rhinovirus carriage and between H. influenzae and M. catarrhalis carriage. Dual carriage of H. influenzae and M. catarrhalis was strongly associated with S. pneumoniae carriage (OR = 6.22). Finally, our model showed that M. catarrhalis carriage was negatively associated with K. pneumoniae carriage. Chronic respiratory disease was associated with symptoms of LRTI. K. pneumoniae, M. catarrhalis-S. aureus and H. influenzae-rhinovirus dual carriage was associated with LRTI symptoms. Our data suggest that RTIs at the Hajj are a result of complex interactions between a number of respiratory viruses and bacteria.