[When some Flaviviruses are throwing our certainties]. / Quand certains flavivirus remettent en cause nos certitudes.

During the past two decades, a number of mosquito-borne flaviviruses, mainly of African origin, have invaded new geographical areas where they have never been active. This was the case for the Japanese encephalitis virus which reached the northeastern part of Australia (1995) and, above all, for the West Nile virus which, since 1999, entirely colonized the American continent. Then, the Usutu virus invaded a large part of the Western Europe (2001) while the Zika virus caused a large epidemic in an island of Micronesia (2007). Finally, in 2010, the Tembusu virus devastated many duck farms in China while the Bagaza virus, after having provoked human encephalitis in India, reached the southern part of Spain. In the affected areas, new pathogenic outcomes were observed in humans and animals while new vertebrate hosts and mosquito species were infected. Moreover, unusual ways of contamination were described. The origins of this unprecedented evolution remain to be clarified.

[Asymptomatic infections in man: a Trojan horse for the introduction and spread of mosquito-borne arboviruses in non-endemic areas?]. / Infections inapparentes chez l'Homme : un cheval de Troie pour l'introduction et la diffusion des arbovirus transmis par des moustiques dans les régions non endémiques ?

In mosquito-borne arbovirus infections in man the asymptomatic cases are much more frequent than the symptomatic ones, but their true role in the introduction and subsequent spread of such diseases in non-endemic areas remains to be clarified. We have collected pertinent data from English and French literature from 1952 to 2010 through Pubmed and other bibliographic sources. Data were analysed to assess if viremia in asymptomatic human arbovirus infections might be sufficient to represent a true risk for introduction in non-endemic areas. During dengue and chikungunya fever outbreaks, humans are believed to be the only vertebrate hosts. Since a very large number of individuals are infected and since viremic levels are known to vary by many orders of magnitude in symptomatic patients, it is reasonable to augur that a proportion of asymptomatic cases might reach levels of viremia sufficient to infect competent mosquitoes. Moreover, in both dengue and chikungunya fever, nosocomial infections have been identified representing an alternative opportunity for virus introduction in non-endemic areas. In zoonotic mosquito-borne arbovirus infections such as Japanese encephalitis or West Nile infection, the situation is quite different since humans are considered as "dead-end" hosts. However, the very large number of asymptomatic cases arising during outbreaks and the existence of newly recognised ways of contamination (blood transfusion, organ transplantation, transplacental way etc.) may also ensure their introduction and subsequent spread in new areas.

[Mosquito-borne arboviruses and pregnancy: pathological consequences for the mother and infant. A general review]. / Grossesse et arbovirus transmis par des moustiques: conséquences pathologiques pour la mère et l'enfant. Une revue générale.

Vertical transmission of arboviruses, mainly those transmitted by mosquitoes, was considered for a long time as an exceptional event in pregnant women. However, during the recent years, as a result of the global upsurge of these viral infections, several surveys and reports clearly demonstrated that the resulting pathologies were increasing in both severity and frequency in endemic countries where pregnant women are at risk. In order to better assess such new epidemiological trends, the authors performed a general review as exhaustive as possible of the pathological consequences of the infection during pregnancy caused by the four dengue viruses and Japanese encephalitis, West Nile and Chikungunya viruses. At the therapeutic and preventive levels we are quite unarmed in the face of such severe accidents as their pathogenesis remains presently unclear

[Assessing epidemiological consequences two years after the tsunami of 26 December 2004?]. / Le tsunami du 26 décembre 2004: quel bilan épidémiologique deux ans plus tard?

In December 2004, a very devastating tsunami struck the coasts of a number of countries along the Indian Ocean inducing about 280,000 deaths and at least 125,000 injured persons. As after such disaster the occurrence of large epidemics of cholera, malaria or arbovirus infections are to be expected. In fact, two years later, no outbreak has been reported among the exposed populations and this is probably the usual outcome for such disasters. However an real increase in number of cases of melioidosis and many bacterial or fungic infections affecting the pulmonary tract, the skin and the injured soft tissues, was noted mainly in repatriated tourists. These latter infections were due to rare or atypical, frequently multiresistant, microorganisms.

[Anthropocene and Emerging viral diseases]. / Anthropocène et viroses émergentes.

We propose to bring together the new geologic concept of Anthropocene and its consequences on our environment with the observed increasing emergence of new viruses - a pathogen for both humans and animals, mainly since the mid of the twentieth century.

Evaluation of mechanical transmission of HIV by the African soft tick, Ornithodoros moubata.

OBJECTIVES: To assess the ability of the African Hut Tampan, Ornithodoros moubata, to mechanically transmit HIV-1 and to re-appraise HIV-1 infectivity in an arthropod cell line at 28 and 35 degrees C. DESIGN: To evaluate HIV-1 transmission by O. moubata, as determined by HIV-1 survival, 'blood-meal' size and interval between feeds, various tick developmental stages were allowed to feed on a heavily infected lymphoblast-rich blood-meal containing HIV-1BRU in an in vitro feeding chamber. METHODS: Blood-meal regurgitation was evaluated using 51Cr-labelled human erythrocytes, and human lymphoblast survival in ticks using Trypan blue. HIV-1 survival in ticks was evaluated by reverse transcriptase activity in tick homogenates cocultured with CEM lymphoblasts. Polymerase chain reaction and Southern blot analysis were used to detect proviral HIV-1 in arthropod cells in vitro. RESULTS: HIV-1BRU remained viable for up to 10 days with O. moubata adults. This is the longest recorded survival of HIV in an arthropod. In agreement with other studies. O. moubata regurgitated part of its previous blood-meal into the feeding lesion. Human CEM lymphoblasts partially survived for up to 7 days at 28 and 35 degrees C inside O. moubata's digestive tract. The blood-meal of adult female ticks was as high as 240 microliters (approximately 70 times more than a mosquito), while the most likely potential mechanical vectors (fourth- and fifth-stage nymphs) ingested an average of 39 microliters (maximum, 73 microliters), with some ticks re-feeding as early as 14 days postfeed in the absence of a moult. Shortcomings associated with the experimental protocol suggest that HIV survival within O. moubata may reach 14 days following natural infection, or that ticks might re-feed earlier. Although HIV-1BRU and HIV-1NDK were unable to replicate at 28 and 35 degrees C in CD4- Aedes albopictus C6/36 mosquito cells, HIV-1NDK was detected in its proviral form. CONCLUSIONS: Our investigations showed that mechanical transmission of HIV-1 by O. moubata is unlikely to occur in the laboratory. This may not be the situation under field conditions.

PIP: In an in vitro feeding chamber, African Hut Tampan ticks (Ornithodoros moubata) fed on CEM lymphoblast-rich human blood containing a copious amount of HIV-1 BRU so that the ability of the tick to transmit HIV-1 at 28 and 35 degrees Celsius--ambient temperatures in some parts of Africa--could be examined. The authors also used Aedes albopictus mosquito cells and HIV-1 BRU and HIV-1 NDK to reexamine HIV-1 infectivity in an arthropod cell line at 28 and 35 degrees Celsius. Some adult female ticks ingested as much as 240 mcl of blood, about 70 times the amount ingested by mosquitoes (mean, 106.3 mcl). On the other hand, the fourth and fifth stage nymphs which are the most likely mechanical vectors of HIV consumed a mean of 39 mcl (maximum, 73 mcl). The shortest interval between feeds for nymphs which had not yet molted was 14 days. But other studies suggested that ticks often refeed sooner than 14 days. The ticks regurgitated part of their previous blood meal into the feeding lesion when they later fed on a suckling mouse. Adult ticks harbored viable HIV-1 BRU for as long as 10 days, the longest recorded survival of HIV in an arthropod. Yet, other evidence indicated that HIV survival in O. moubata under natural conditions could actually be 14 days. 4.5% and 1.3% of human CEM lymphoblasts remained viable up to 7 days in the ticks' digestive tract at 28 and 35 degrees Celsius, respectively. Neither HIV-1 BRU nor HIV-1 NDK could replicate in CD4-A. albopictus C6/36 mosquito cells, but the authors did find some evidence of retrotranscription of HIV-1 is probably not possible in vitro, but it could contribute somewhat to HIV-1 transmission in areas of Central Africa where HIV prevalence is high.

Multiplication and persistence of Spiroplasma melliferum strain A56 in experimentally infected suckling mice.

Strain A56 of the bee pathogen Spiroplasma melliferum was isolated from a honeybee (Apis mellifera) during ecological studies on mosquito spiroplasmas in Savoie (France). When inoculated intracerebrally (i.c.) into 48-h old suckling mice, this strain was found to replicate to very high titres and to persist in brain for up to 9 months in one individual. We attempted to increase the "neurotropism" of A56 by sequential i.c. passages. During the first two passages, multiplication of the organisms was observed at very high titres in suckling mouse brain (10(7) to 10(11) CCU/ml) generally without the appearance of antibody, thus mimicking the so-called "immunological tolerance" phenomenon. Intracerebral multiplication of A56 decreased during the third passage (10(2) to 10(4) CCU/ml) and ceased during the fourth passage. Spiroplasma multiplication in brain was apparently well tolerated, since brain lesions were minimal and clinical symptoms were limited to a clear, but only rarely significant, delay in growth curves of inoculated versus non-inoculated mice. Progressive spongiform encephalopathy was never observed. Strain A56 S. melliferum appears as the second spiroplasma, after the tick-derived Spiroplasma mirum capable of multiplying in both invertebrate and vertebrate hosts.

Combination therapy for dendritic keratitis with human leukocyte interferon and acyclovir.

We treated 45 patients with virologically verified dendritic keratitis with a combination of interferon and acyclovir 3% or with placebo and acyclovir 3% in a double-masked study. One drop of human leukocyte interferon (30 X 10(6) IU/ml) or albumin-placebo was administered daily. Acyclovir ointment was applied five times daily. The mean healing time of the corneal ulcers in 24 patients treated with interferon and acyclovir was 3.9 days and the mean healing time in 21 patients treated with placebo and acyclovir was seven days. The difference was significant (P less than .001).

Salmonella-infected subdural haematoma.

Post-traumatic chronic subdural haematoma infected by Salmonella sandiego is reported in a 55-year-old alcoholic man. Treatment involved a four-weeks' course of chloramphenicol and also subdural drainage. The patient ultimately recovered. Only four such cases have been reported in the literature. The mode of infection of the subdural haematoma is presumed to have been haematogenous in the absence of an otorhinological focus, meningitis or previous neurosurgery.

Renal failure in the course of reactivation of varicella-zoster virus infection in a renal transplant recipient.

Renal failure developed in a 20-year-old female renal transplant recipient in the course of reactivation of varicella-zoster virus infection. The patient was treated with acyclovir and immunosuppression was continued. The year later renal function in the transplanted kidney was satisfactory.

Detection of Israel turkey meningo-encephalitis virus from mosquito (Diptera: Culicidae) and Culicoides (Diptera: Ceratopogonidae) species and its survival in Culex pipiens and Phlebotomus papatasi (Diptera: Phlebotomidae).

Israel turkey meningo-encephalitis (ITME) virus was detected in pools of Ochlerotatus caspius Pallas and Culicoides imicola Kieffer trapped at a turkey run at Nir David during an outbreak in August 1995. Experimental membrane feeding on a blood ITME suspension showed that Culex pipiens L. became harbored virus for at least 14 d. When Phlebotomus papatasi Scopoli were fed on an infected turkey, they became infected and harbored the virus for at least 7 d. Because Phlebotomines are trapped frequently at turkey runs in Israel, they should be suspected as potential vectors of ITME.

Spiroplasma (Mollicutes: Spiroplasmataceae) pathogenic for Aedes aegypti and Anopheles stephensi (Diptera: Culicidae).

Intrathoracic inoculation with the mosquito spiroplasma, Spiroplasma taïwanense Abalain-Colloc et al., was found to reduce significantly the survival of adult male and female Aedes aegypti (L.) and Anopheles stephensi Liston. This spiroplasma also reduced significantly the flight capacity of adult female Ae. aegypti 5-8 d after inoculation and adult female An. stephensi 4 d after inoculation. Adult female An. stephensi were incapable of flight 5 d after inoculation. As such, S. taïwanense joins Bacillus thuringiensis and B. sphaericus as bacteria known to be pathogenic for mosquito vectors.

Three spiroplasmas isolated from Haematopota sp. (Diptera:Tabanidae) in France.

On August 1991, three spiroplasmas (Tab 2A, Tab 2B and Tab 4C) were isolated from Haematopota sp. flies collected from Indre-et-Loire, France. Isolations were made at 28 degrees C in MD1 medium from ground individual flies, but not from external washings. All isolates adapted well to SP4 medium at 30 and 37 degrees C and were triple cloned before serological identification. Using the cross deformation test, the 3 isolates were compared with 42 known spiroplasmas isolated from diseased plants, flowers, various insects and ticks belonging to 25 serological groups. Each isolate cross-reacted with others and exhibited weak 1-way reactions with TABS-2 or PLHS-1, two spiroplasmas isolated in the United States from respectively Tabanus abactor Philip and Panorpa helena L, a scorpion-fly. These results suggest that Tab 2A, Tab 2B and Tab 4C together with TABS-2 and PLHS-1 may represent, members of a new serological supergroup.

Use of collagen shields in the treatment of herpetic keratitis.

Eighteen patients with typical Herpes simplex virus dendritic keratitis confirmed by viral isolation were treated with corneal collagen shields presoaked with trifluorothymidine for 15 minutes and trifluorothymidine eye drops 5 times daily. The average healing time was 2.9 days (range 1-7 days). No allergic reactions were observed. Toxic punctate keratitis occurred in 3 eyes. The results of this open study suggest that the effect of collagen corneal shields in conjunction with trifluorothymidine shortens the average epithelial healing time compared with other studies that have used antiviral drugs alone.

Randomized study of minocycline + gentamicin compared with metronidazole + gentamicin for prophylaxis or treatment of mixed infections in abdominal surgery.

Seventy patients admitted for abdominal surgery requiring short-term perioperative prophylaxis were randomized to receive minocycline + gentamicin or metronidazole + gentamicin. Thirty patients were considered to be infected at the time of surgery and were treated with the same regimen. In the prophylactic cohort, one patient from each group developed postoperative fever. One patient receiving minocycline developed a wound infection. The overall infection rate was 2.6%. In the treatment cohort, it appeared that the patients receiving metronidazole had more severe underlying diseases than those receiving minocycline. Consequently, more postoperative non-infectious complications were observed in the former. Minocycline + gentamicin appeared at least as effective than metronidazole + gentamicin in preventing postoperative infectious complications associated with abdominal surgery or in treating intra-abdominal infections.

[Can arboviruses from seabird colonies in Brittany infect man?]. / Les arbovirus des colonies d'oiseaux de mer de Bretagne peuvent-ils infecter l'homme?

Four tick-borne arboviruses circulate heavily and permanently among the seabirds colonies located along the coasts of Brittany: Soldado, Zaliv Terpeniya, Avalon and a member of Tyuleniy subgroup of flaviviruses. In order to appreciate the ability of these viruses to infect man, the authors studied for antibodies the sera of farmers living in South-Finistere, in the vicinity of Cape Sizun seabirds reserve. Antibodies were actually found on 14 of 474 farmers, or 3.0 per cent, substantiating the reality of infection by these agents. The possible mechanisms of the contamination and the eventual pathologic results of these viral infections are discussed.

Antigenic variants of the Soldado virus (Nairovirus, Bunyaviridae) isolated in different parts of the world.

Antigenic analysis of 9 strains of the Soldado virus, originating from seven different countries of Central and Northern America, Africa, Northern Europe and of the Pacific area was carried out by means of complement fixation (CF) and immunodiffusion (ID) tests. Three strains isolated from Ornithodoros (A.) capensis, including the reference Trinidad strain, were found to be related within the same relatively heterogeneous sub-group C, being characteristic for the New World. Five other strains isolated from Ornithodoros (A.) maritimus were classified to form an another, much more homogeneous subgroup M, characteristic for the Old World (related to the Ireland strain). The South Africa strain, isolated form Ornithodoros (A.), probably capensis, could not be classified in either of the above two subgroups. Thus, the Soldado virus in fact represents a complex of more or less closely related strains, but not a single virus.

The use of scanning electron microscopy in the study of haemagglutination induced by various arboviruses.

Scanning electron microscopy was used to study haemagglutination by 10 arboviruses belonging to the Togaviridae and Bunyaviridae families. The pictures obtained did not allow to clarify the precise mechanism of haemagglutination by these viruses. The data suggest that no fundamental differences exist in the mechanism of haemagglutination between these two arbovirus families.

Avalon virus, Sakhalin group (Nairovirus, Bunyaviridae) from the seabird tick Ixodes (Ceratixodes) uriae White 1852 in France.

Nine strains of Avalon virus were isolated from Ixodes uriae ticks collected in the Cape Sizun seabird reserve, Brittany, from 1979 to 1985, during a longitudinal study of consequences of tick-borne infections for kittiwakes (Rissa tridactyla). Avalon virus strains isolated in France proved difficult to study owing to the weak infectious titres they exhibited in suckling mice or cultured cells. However, some interesting data concerning the ecology of virus infection and the morphology of the virions were obtained and are discussed.

Essaouira and Kala iris: two new orbiviruses of the Kemerovo serogroup, Chenuda complex, isolated from Ornithodoros (Alectorobius) maritimus ticks in Morocco.

Essaouira and Kala Iris viruses were isolated from Ornithodoros (Alectorobius) maritimus ticks parasitizing yellow-legged gulls (Larus cachinnans) on the coast of Morocco in 1979 and 1981, respectively. Serological evidence indicates that these two viruses are new members of the Chenuda complex within the Kemerovo serogroup of the genus Orbivirus. Ecological, pathological, morphological, and physicochemical properties are compatible with these findings. The infectivity of these viruses for man and animals, including seabirds, remains unknown.