Insight into COVID-19's epidemiology, pathology, and treatment.

The newly emerged 2019 coronavirus disease (COVID-19) has urged scientific and medical communities to focus on epidemiology, pathophysiology, and treatment of SARS-CoV-2. Indeed, little is known about the virus causing this severe acute respiratory syndrome pandemic, coronavirus (SARS-CoV-2). Data already collected on viruses belonging to the coronaviridae family are of interest to improve our knowledge rapidly on this pandemic. The current review aims at delivering insight into the fundamental advances inSARS-CoV-2 epidemiology, pathophysiology, life cycle, and treatment.

Scorpion-Derived Antiviral Peptides with a Special Focus on Medically Important Viruses: An Update.

The global burden of viral infection, especially the current pandemics of SARS-CoV-2, HIV/AIDS, and hepatitis, is a very risky one. Additionally, HCV expresses the necessity for antiviral therapeutic elements. Venoms are known to contain an array of bioactive peptides that are commonly used in the treatment of various medical issues. Several peptides isolated from scorpion venom have recently been proven to possess an antiviral activity against several viral families. The aim of this review is to provide an up-to-date overview of scorpion antiviral peptides and to discuss their modes of action and potential biomedical application against different viruses.

Urbanization of human visceral leishmaniasis in Morocco.

Human visceral leishmaniasis one of the seven most neglected tropical diseases in the world. In Morocco, HVL is widespread in all regions; but it is more common in the northern part with sporadic cases observed in the South. During the period between 2004 and 2013, the most affected Moroccan provinces were Taounate province, with 220 cases (16.09% of all cases), followed by Chefchaouen with 13.17% and Taza with 10.46% of the total cases. Children < 5 years old are the most affected age group, most cases registered were male. Geographic distribution of HVL showed predominance in rural areas but we noted that it's opening to be urban.

Species composition of sand flies and bionomics of Phlebotomus papatasi and P. sergenti (Diptera: Psychodidae) in cutaneous leishmaniasis endemic foci, Morocco.

BACKGROUND: Cutaneous Leishmaniasis (CL) is one of the most neglected tropical diseases in Morocco. Leishmania major and L. tropica are the main culprits identified in all endemic foci across the country. These two etiological agents are transmitted by Phlebotomus papatasi and P. sergenti, the two most prevalent sand fly species in Morocco. Previous studies reflected gaps of knowledge regarding the environmental fingerprints that affect the distribution of these two potential vectors across Morocco. METHODS: The sand flies were collected from 48 districts across Morocco using sticky paper traps. Collected specimens were preserved in 70% ethanol for further processing and identification. Male and female densities were calculated in each site to examine their relations to the environmental conditions across these sites. The study used 19 environmental variables including precipitation, aridity, elevation, soil variables and a composite representing maximum, minimum and mean of day- and night-time Land Surface Temperature (LST), and Normalized Difference Vegetation Index (NDVI). RESULTS: A total of 11,717 specimens were collected during this entomological survey. These specimens represented 11 species of two genera; Phlebotomus and Sergentomyia. Correlations of the sand fly densities with the environmental variables were estimated to identify the variables which influence the distribution of the two potential vectors, Phlebotomus papatasi and P. sergenti, associated with all CL endemic foci across the country. The density of P. papatasi was most affected by temperature changes. The study showed a significant positive correlation between the densities of both sexes of P. papatasi and night-time temperatures. Both P. papatasi and P. sergenti showed a negative correlation with aridity, but, such correlation was only significant in case of P. papatasi. NDVI showed a positive correlation only with densities of P. sergenti, while, soil PH and soil water stress were negatively correlated with the densities of both males and females of only P. papatasi. CONCLUSIONS: Our results identified the sand fly species across all CL endemic sites and underlined the influences of night-time temperature, soil water stress and NDVI as the most important variables affecting the sand fly distribution in all sampled sites. This preliminary study considered the importance of these covariates to anticipate the potential distribution of P. papatasi and P. sergenti in Morocco.

Ecological and epidemiological status of species of the Phlebotomus perniciosus complex (Diptera: Psychodidae, Phlebotominae) in Morocco.

Leishmania infantum (Kinetoplastida: Trypanosomatidae) infection is transmitted by an infected female sand fly (Diptera: Psychodidae, Phlebotominae) of the subgenus Larroussius: Phlebotomus ariasi, Phlebotomus perniciosus, and Phlebotomus longicuspis in the Mediterranean basin. In Morocco, the vectorial role of P. ariasi was demonstrated, while that of P. longicuspis and P. perniciosus is not elucidated. In addition, Moroccan P. longicuspis and P. perniciosus populations present a higher morphologic and genetic variability. It was classified as P. perniciosus complex, including typical (PN) and atypical (PNA) morphs of P. perniciosus, P. longicuspis sensu stricto (LCss), and a sibling species of P. longicuspis (LCx). With the aim to study the ecological and epidemiological status of P. perniciosus complex species in Morocco, entomological surveys were carried out during three entomological seasons (2012, 2013, and 2014). We collected a total of 6298 specimens from 81 localities of northern, central, and southern Morocco. After describing the geographical distribution of P. perniciosus complex trough Morocco according to many variables (altitude, latitude, and longitude), we discuss the resulting epidemiological implications of its species. Our results highlight the geographical distribution of the two morphs of P. perniciosus through Morocco: PN is limited to the north, while PNA is widespread in northern, central, and southern Morocco. In terms of vectorial role, we hypothesize the potential involvement of PN, LCss, and LCx, at least, with P. ariasi, in the epidemiological cycle of L. infantum in Morocco.

Species composition of phlebotomine sand fly fauna in an area with sporadic cases of Leishmania infantum human visceral leishmaniasis, Morocco.

Visceral and cutaneous leishmaniases are the main endemic vector-born diseases in Morocco. Human visceral leishmaniasis (HVL), by Leishmania infantum, currently presents a significant health problem throughout the country and may constitute factor for death, especially among children with less than 15 years old. In the past, HVL has been basically absent or at least sporadic in Marrakesh-Tensift-Al Haouz region; however it became significant during the last decade. An entomological survey and a retrospective study on L. infantum HVL cases had been carried out to assess the risk of the disease apparition in this region. 7046 sand flies (Diptera: Psychodidae) were collected and studied from twelve localities within Marrakesh-Tensift-Al Haouz region. The result shows the presence of ten sand fly species, 58.76% from the genus Phlebotomus and 41.24% from genus Sergentomyia. A further analysis indicates that Phlebotomus perniciosus, Phlebotomus longicuspis and Phlebotomus ariasi species, incriminated vectors of L. infantum, are dominant (35.56%), so, we describe their spatial (according to altitude and biotopes) and temporal (seasonal activity) distribution in study area.

Linking climate to incidence of zoonotic cutaneous leishmaniasis (L. major) in pre-Saharan North Africa.

Shifts in surface climate may have changed the dynamic of zoonotic cutaneous leishmaniasis (ZCL) in the pre-Saharan zones of North Africa. Caused by Leishmania major, this form multiplies in the body of rodents serving as reservoirs of the disease. The parasite is then transmitted to human hosts by the bite of a Phlebotomine sand fly (Diptera: Psychodidae) that was previously fed by biting an infected reservoir. We examine the seasonal and interannual dynamics of the incidence of this ZCL as a function of surface climate indicators in two regions covering a large area of the semi-arid Pre-Saharan North Africa. Results suggest that in this area, changes in climate may have initiated a trophic cascade that resulted in an increase in ZCL incidence. We find the correlation between the rainy season precipitation and the same year Normalized Difference Vegetation Index (NDVI) to be strong for both regions while the number of cases of ZCL incidence lags the precipitation and NDVI by 2 years. The zoonotic cutaneous leishmaniasis seasonal dynamic appears to be controlled by minimum temperatures and presents a 2-month lag between the reported infection date and the presumed date when the infection actually occurred. The decadal increase in the number of ZCL occurrence in the region suggests that changes in climate increased minimum temperatures sufficiently and created conditions suitable for endemicity that did not previously exist. We also find that temperatures above a critical range suppress ZCL incidence by limiting the vector's reproductive activity.

WITHDRAWN: Epidemiological role of Phlebotomus papatasi and P. sergenti populations in Morocco: What we know and what can we learn from the field?

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