Cowpox virus (CPXV) has an animal reservoir and is typically transmitted to humans by contact with infected animals. In 2017, CPXV infection of a pregnant woman in France led to the death of her ...fetus. Fetal death after maternal orthopoxvirus (smallpox) vaccination has been reported; however, this patient had not been vaccinated. Investigation of the patient's domestic animals failed to demonstrate prevalence of CPXV infection among them. The patient's diagnosis was confirmed by identifying CPXV DNA in all fetal and maternal biopsy samples and infectious CPXV in biopsy but not plasma samples. This case of fetal death highlights the risk for complications of orthopoxvirus infection during pregnancy. Among orthopoxviruses, fetal infection has been reported for variola virus and vaccinia virus; our findings suggest that CPXV poses the same threats for infection complications as vaccinia virus.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Current approved COVID-19 vaccines, notably mRNA and adenoviral vectored technologies, still fail to fully protect against infection and transmission of various SARS-CoV-2 variants. The mucosal ...immunity at the upper respiratory tract represents the first line of defense against respiratory viruses such as SARS-CoV-2 and is thus critical to develop vaccine blocking human-to-human transmission.
We measured systemic and mucosal Immunoglobulin A (IgA) response in serum and saliva from 133 healthcare workers from Percy teaching military hospital following a mild infection (SARS-CoV-2 Wuhan strain, n=58) or not infected (n=75), and after SARS-CoV-2 vaccination (Vaxzevria®/Astrazeneca and/or Comirnaty®/Pfizer).
While serum anti-SARS-CoV-2 Spike IgA response lasted up to 16 months post-infection, IgA response in saliva had mostly fallen to baseline level at 6 months post-infection. Vaccination could reactivate the mucosal response generated by prior infection, but failed to induce a significant mucosal IgA response by itself. Early post-COVID-19 serum anti-Spike-NTD IgA titer correlated with seroneutralization titers. Interestingly, its saliva counterpart positively correlated with persistent smell and taste disorders more than one year after mild COVID-19.
As breakthrough infections have been correlated with IgA levels, other vaccine platforms inducing a better mucosal immunity are needed to control COVID-19 infection in the future. Our results encourage further studies to explore the prognosis potential of anti-Spike-NTD IgA in saliva at predicting persistent smell and taste disorders.
The primary vector at the origin of the 2007 outbreak in Libreville, Gabon is identified as Aedes albopictus, trapped around the nearby French military camp. The Chikungunya virus was isolated from ...mosquitoes and found to be identical to the A226V circulating human strain. This is the first field study showing the role of the recently arrived species Aedes albopictus in Chikungunya virus transmission in Central Africa, and it demonstrates this species' role in modifying the epidemiological presentation of Chikungunya in Gabon.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In Gabon, vector transmission has been poorly studied. Since the implementation of the Roll Back malaria recommendations, clinical studies have shown a decline in the burden of malaria in Libreville, ...the capital city of Gabon. To better understand the transmission dynamic in Libreville, an entomological survey was conducted in five districts of the city.
Mosquitoes were sampled by human landing collection during 1 year in five districts of Libreville: Alibandeng, Beauséjour, Camp des Boys and Sotega. Mosquitoes were identified morphologically and by molecular methods. The Plasmodium falciparum circumsporozoïte indices were measured by ELISA, and the entomological inoculation rates (EIR) were calculated for all areas. Molecular assessments of pyrethroid knock down resistance (kdr) and of insensitive acetylcholinesterase resistance were conducted.
A total of 57,531 mosquitoes were caught during 341 person-nights (161 person-nights indoor and 180 person-nights outdoor) among which, 4,223 were Anopheles gambiae s.l. The average Human Biting Rate fell from 15.5 bites per person during the rainy season to 4.7 during the dry season. The An. gambiae complex population was composed of An. gambiae s.s molecular form S (99.5%), Anopheles melas (0.3%) and An. gambiae s.s. form M (0.2%). Thirty-three out of 4,223 An. gambiae s.l. were found to be infected by P. falciparum (CSP index = 0.78%). The annual EIR was estimated at 33.9 infected bites per person per year ranging from 13 in Alibandeng to 88 in Sotega. No insensitive AChE mutation was identified but both kdr-w and kdr-e mutations were present in An. gambiae molecular form S with a higher frequency of the kdr-w allele (76%) than the kdr-e allele (23.5%).
Malaria transmission in Libreville occurred mainly during the rainy season but also during the dry season in the five districts. Transmission level is high and seems to be very heterogeneous in the town. Interestingly, the highest EIR was recorded in the most central and urbanized quarter and the lowest in a peripheral area. The decrease of transmission usually seen from peri-urban areas to urban centers is probably more dependent of the socio-economic level of a quarter than of its location in the city. Urban malaria control programmes need to consider the socio economic level of an area rather than the location in the city in order to determine the areas most favourable to malaria transmission.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Urbanization has a great impact on the composition of the vector system and malaria transmission dynamics. In Dakar, some malaria cases are autochthonous but parasite rates and incidences of clinical ...malaria attacks have been recorded at low levels. Ecological heterogeneity of malaria transmission was investigated in Dakar, in order to characterize the Anopheles breeding sites in the city and to study the dynamics of larval density and adult aggressiveness in ten characteristically different urban areas.
Ten study areas were sampled in Dakar and Pikine. Mosquitoes were collected by human landing collection during four nights in each area (120 person-nights). The Plasmodium falciparum circumsporozoite (CSP) index was measured by ELISA and the entomological inoculation rates (EIR) were calculated. Open water collections in the study areas were monitored weekly for physico-chemical characterization and the presence of anopheline larvae. Adult mosquitoes and hatched larvae were identified morphologically and by molecular methods.
In September-October 2007, 19,451 adult mosquitoes were caught among which, 1,101 were Anopheles gambiae s.l. The Human Biting Rate ranged from 0.1 bites per person per night in Yoff Village to 43.7 in Almadies. Seven out of 1,101 An. gambiae s.l. were found to be positive for P. falciparum (CSP index = 0.64%). EIR ranged from 0 infected bites per person per year in Yoff Village to 16.8 in Almadies. The An. gambiae complex population was composed of Anopheles arabiensis (94.8%) and Anopheles melas (5.2%). None of the An. melas were infected with P. falciparum. Of the 54 water collection sites monitored, 33 (61.1%) served as anopheline breeding sites on at least one observation. No An. melas was identified among the larval samples. Some physico-chemical characteristics of water bodies were associated with the presence/absence of anopheline larvae and with larval density. A very close parallel between larval and adult densities was found in six of the ten study areas.
The results provide evidence of malaria transmission in downtown Dakar and its surrounding suburbs. Spatial heterogeneity of human biting rates was very marked and malaria transmission was highly focal. In Dakar, mean figures for transmission would not provide a comprehensive picture of the entomological situation; risk evaluation should therefore be undertaken on a small scale.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Previous studies in Dakar have highlighted the spatial and temporal heterogeneity of Anopheles gambiae s.l. biting rates. In order to improve the knowledge of the determinants of malaria transmission ...in this city, the present study reports the results of an extensive entomological survey that was conducted in 45 areas in Dakar from 2007 to 2010.
Water collections were monitored for the presence of anopheline larvae. Adult mosquitoes were sampled by human landing collection. Plasmodium falciparum circumsporozoïte (CSP) protein indexes were measured by ELISA (enzyme-linked immunosorbent assay), and the entomological inoculation rates were calculated.
The presence of anopheline larvae were recorded in 1,015 out of 2,683 observations made from 325 water collections. A water pH of equal to or above 8.0, a water temperature that was equal to or above 30°C, the absence of larvivorous fishes, the wet season, the presence of surface vegetation, the persistence of water and location in a slightly urbanised area were significantly associated with the presence of anopheline larvae and/or with a higher density of anopheline larvae. Most of the larval habitats were observed in public areas, i.e., freely accessible. A total of 496,310 adult mosquitoes were caught during 3096 person-nights, and 44967 of these specimens were identified as An.gambiae s.l. The mean An. gambiae s.l. human-biting rate ranged from 0.1 to 248.9 bites per person per night during the rainy season. Anopheles arabiensis (93.14%), Anopheles melas (6.83%) and An. gambiae s.s. M form (0.03%) were the three members of the An. gambiae complex. Fifty-two An. arabiensis and two An. melas specimens were CSP-positive, and the annual CSP index was 0.64% in 2007, 0.09% in 2008-2009 and 0.12% in 2009-2010. In the studied areas, the average EIR ranged from 0 to 17.6 infected bites per person during the entire transmission season.
The spatial and temporal heterogeneity of An. gambiae s.l. larval density, adult human-biting rate (HBR) and malaria transmission in Dakar has been confirmed, and the environmental factors associated with this heterogeneity have been identified. These results pave the way for the creation of malaria risk maps and for a focused anti-vectorial control strategy.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Urban malaria is a major health priority for civilian and militaries populations. A preliminary entomologic study has been conducted in 2006-2007, in the French military camps of the two mains towns ...of Gabon: Libreville and Port-Gentil. The aim was to assess the malaria transmission risk for troops.
Mosquitoes sampled by human landing collection were identified morphologically and by molecular methods. The Plasmodium falciparum circumsporozoïte (CSP) indexes were measured by ELISA, and the entomological inoculation rates (EIR) were calculated for both areas. Molecular assessments of pyrethroid knock down (kdr) resistance and of insensitive acetylcholinesterase resistance were conducted.
In Libreville, Anopheles gambiae s.s. S form was the only specie of the An. gambiae complex present and was responsible of 9.4 bites per person per night. The circumsporozoïte index was 0.15% and the entomological inoculation rate estimated to be 1.23 infective bites during the four months period. In Port-Gentil, Anopheles melas (75.5% of catches) and An. gambiae s.s. S form (24.5%) were responsible of 58.7 bites per person per night. The CSP indexes were of 1.67% for An. gambiae s.s and 0.28% for An. melas and the EIRs were respectively of 1.8 infective bites per week and of 0.8 infective bites per week. Both kdr-w and kdr-e mutations in An. gambiae S form were found in Libreville and in Port-Gentil. Insensitive acetylcholinesterase has been detected for the first time in Gabon in Libreville.
Malaria transmission exists in both town, but with high difference in the level of risk. The co-occurrence of molecular resistances to the main families of insecticide has implications for the effectiveness of the current vector control programmes that are based on pyrethroid-impregnated bed nets.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
According to entomological studies conducted over the past 30 years, there was low malaria transmission in suburb of Dakar but little evidence of it in the downtown area. However; there was some ...evidence of local transmission based on reports of malaria among permanent residents. An entomological evaluation of malaria transmission was conducted from May 2005 to October 2006 in two areas of Dakar.
Mosquitoes were sampled by human landing collection during 34 nights in seven places in Bel-air area (238 person-nights) and during 24 nights in five places in Ouakam area (120 person-nights). Mosquitoes were identified morphologically and by molecular methods. The Plasmodium falciparum circumsporozoïte indexes were measured by ELISA, and the entomological inoculation rates (EIR) were calculated for both areas. Molecular assessments of pyrethroid knock down resistance (Kdr) and of insensitive acetylcholinesterase resistance were conducted.
From May 2005 to October 2006, 4,117 and 797 Anopheles gambiae s.l. respectively were caught in Bel-air and Ouakam. Three members of the complex were present: Anopheles arabiensis (> 98%), Anopheles melas (< 1%) and An. gambiae s.s. molecular form M (< 1%). Infected mosquitoes were caught only during the wintering period between September and November in both places. In 2005 and 2006, annual EIRs were 9,5 and 4, respectively, in Bel-air and 3 and 3, respectively, in Ouakam. The proportion of host-seeking An. gambiae s.l. captured indoors were 17% and 51% in Bel air and Ouakam, respectively. Ace 1 mutations were not identified in both members of the An. gambiae complex. Kdr mutation frequency in An. arabiensis was 12% in Bel-air and 9% in Ouakam.
Malaria is transmitted in Dakar downtown area. Infected mosquitoes were caught in two subsequent years during the wintering period in two distant quarters of Dakar. These data agree with clinical data from a Senegalese military Hospital of Dakar (Hospital Principal) where most malaria cases occurred between October and December. It was the first detection of An. melas in Dakar.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Malaria remains a major threat, to both travellers and military personnel deployed to endemic areas. The recommendations for travellers given by the World Health Organization is based on the ...incidence of malaria in an area and do not take the degree of exposure into account. The aim of this article is to evaluate the exposure of travellers by entomologic methods, which are the commonly used measures of the intensity of malaria transmission.
From February 2004 to June 2004, five groups of 30 military personnel were stationed in up to 10 sites in western Côte d'Ivoire, from one week to several months. Adult mosquitoes were collected by human landing catches at each site during the five months and the level of exposure to malaria transmission of each group was estimated.
The level of transmission varied from one site to another one from less than one to approximately more than 100 infective bites per month. In the majority of sites, at least two anopheline species were involved in transmission. The cumulative EIR over the study period varied according to the groups from 29 infected bites per person/per mission to 324.
The level of malaria transmission and malaria risk varies widely (varying by a factor of eleven) between groups of travellers travelling in the same region and at the same time. Physicians involved in travel medicine or supporting expatriated populations or refugees should consider this heterogeneity and emphasize the importance of combining appropriate measures, such as chemoprophylaxis and protective measures against mosquitoes.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Circulating microRNA (miRNA) are biomarkers of tissue injury or host response to an infection.•We found significant alterations in serum miRNA profile in a mouse model of Crimean-Congo haemorrhagic ...fever.•Some miRNA profiles were close to those reported in other haemorrhagic fever illness or tissue injury.•A combination of 8 miRNAs allowed a 100% discrimination of mice developing a severe illness from control mice.
Crimean-Congo haemorrhagic fever (CCHF) is a severe disease leading to high mortality in humans. Early diagnosis and evaluation of the severity are necessary to improve patient survival. In a model of CCHF virus-infected interferon-receptor-deficient (IFNAR) KO mice, we found a specific circulating miRNA (c-miRNA) profile when compared to wild-type (wt), resistant mice. Among this response, 20 c-miRNA were shown to be specifically altered, including miR-122-5p, miR-216a-5p, 217-5p, miR-29a-3p and miR-511-5p. Using a logistic regression analysis, a combination of 8 miRNAs allowed a 100% discrimination of mice developing a severe illness (IFNAR-KO) from non-detectable clinical signs (wt).
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