Seasonal Patterns of Zoonotic Cutaneous Leishmaniasis Caused by L. major and Transmitted by Phlebotomus papatasi in the North Africa Region, a Systematic Review and a Meta-Analysis

BACKGROUND: In North African countries, zoonotic cutaneous leishmaniasis (ZCL) is a seasonal disease linked to Phlebotomus papatasi, Scopoli, 1786, the primary proven vector of L. major dynamics. Even if the disease is of public health importance, studies of P. papatasi seasonal dynamics are often local and dispersed in space and time. Therefore, a detailed picture of the biology and behavior of the vector linked with climatic factors and the framework of ZCL outbreaks is still lacking at the North African countries' level. Our study aims to fill this gap via a systematic review and meta-analysis of the seasonal incidence of ZCL and the activity of P. papatasi in North African countries. We address the relationship between the seasonal number of declared ZCL cases, the seasonal dynamic of P. papatasi, and climatic variables at the North African region scale. METHODS: We selected 585 publications, dissertations, and archives data published from 1990 to July 2022. The monthly incidence data of ZCL were extracted from 15 documents and those on the seasonal dynamic of P. papatasi from 11 publications from four North African countries. RESULTS: Our analysis disclosed that for most studied sites, the highest ZCL incidence is recorded from October to February (the hibernal season of the vector), while the P. papatasi density peaks primarily during the hot season of June to September. Overall, at the North African region scale, two to four months laps are present before the apparition of the scars reminiscent of infection by L. major. CONCLUSIONS: Such analysis is of interest to regional decision-makers for planning control of ZCL in North African countries. They can also be a rationale on which future field studies combining ZCL disease incidence, vector activity, and climatic data can be built.

A systematic review and global analysis of the seasonal activity of Phlebotomus (Paraphlebotomus) sergenti, the primary vectors of L. tropica.

BACKGROUND: Phlebotomus (Paraphlebotomus) sergenti is a widespread proven vector of Leishmania pathogens causing anthroponotic cutaneous leishmaniasis (ACL), due to L. tropica, in the old world. The activity of P. (Par.) sergenti is seasonal and sensitive to general variations in climate. Phenological data sets can thus provide a baseline for continuing investigations on P. (Par.) sergenti population dynamics that may impact future leishmaniasis transmission and control scenarios. METHODS/PRINCIPAL FINDING: A systematic review of the seasonality of P. (Par.) sergenti was undertaken globally. Six hundred eight scientific papers were identified, and data were extracted from 35 ones, with informative data on sand fly seasonal dynamics on trapping performed from 1992 to December 2021 on 63 sites from 12 countries. Morocco, Saudi Arabia, Iraq, Iran, Pakistan, Palestine, Turkey, Spain, Portugal, Italy, Cyprus, and Georgia. The data extracted from the literature survey were further normalized. Our analysis recorded that the highest P.(Par.) sergenti activity occurs during the hot and dry seasons, primarily in July and August, whatever the location studied. We noticed a relationship between the latitude of sites and sand fly presence (from early April to June) and the type of density trend, varying from a single peak to multiple peaks. On a geographical scale, P. (Par.) sergenti concentrates between 32-37° in latitude in a large interval following the longitude and the highest number of sites with high P. (Par.) sergenti activity is located at the latitude 32°. We also quoted a similar seasonal dynamic and geographic distribution with Phlebotomus (Phlebotomus) papatasi, a proven vector of L. major that causes cutaneous infection. No apparent risk for ACL occurred from December to March, at least in the years and geographic areas considered in this survey. Altogether, knowing that high P. (Par.) sergenti activity would be linked with an increased risk of leishmaniasis transmission, and our study provides information that can be used for control programs on ACL transmission. CONCLUSIONS: Despite variations, we found a relatively homogeneous pattern of P. (Par.) sergenti potential behavior in sites whose data are published. A higher risk for L. tropica transmission was identified in the June-October period. Still, such risk was not equally distributed throughout the area since density waves of adults occurred earlier and were more frequent in some territories, like Saudi Arabia.

Isothermal Nucleic Acid Amplification to Detect Infection Caused by Parasites of the Trypanosomatidae Family: A Literature Review and Opinion on the Laboratory to Field Applicability.

Isothermal amplification of nucleic acids has the potential to be applied in resource-limited areas for the detection of infectious agents, as it does not require complex nucleic purification steps or specific and expensive equipment and reagents to perform the reaction and read the result. Since human and animal infections by pathogens of the Tryponasomatidae family occur mainly in resource-limited areas with scant health infrastructures and personnel, detecting infections by these methodologies would hold great promise. Here, we conduct a narrative review of the literature on the application of isothermal nucleic acid amplification for Trypanosoma and Leishmania infections, which are a scourge for human health and food security. We highlight gaps and propose ways to improve them to translate these powerful technologies into real-world field applications for neglected human and animal diseases caused by Trypanosomatidae.

A conceptual model for understanding the zoonotic cutaneous leishmaniasis transmission risk in the Moroccan pre-Saharan area.

Leishmanioses are of public health concern in Morocco, mainly the Zoonotic Cutaneous Leishmaniasis (ZCL) endemic in the Moroccan pre-Saharian area. Transmission of this disease depends on eco-epidemiological and socio-economic conditions. Therefore, a multivariable approach is required to delineate the risk and intensity of transmission. This will help outline main disease risk factors and understand interactions between all underlying factors acting on disease transmission at a local and regional scale. In this context, we propose a new conceptual model, the Biophysical-Drivers-Response-Zoonotic Cutaneous Leishmaniasis (BDRZCL), adapted to the Pre-Saharian area. The proposed model highlights how the physical and human drivers affect the environment and human health. The incidence of ZCL is linked to human activity and biophysical changes or by their interactions. The human response added to risk drivers are the main components that influence the biophysical part. This model improves our understanding of the cause-effect interactions and helps decision-makers and stakeholders react appropriately.

Geographic distribution of Meriones shawi,Psammomys obesus, and Phlebotomus papatasi the main reservoirs and principal vector of zoonotic cutaneous leishmaniasis in the Middle East and North Africa.

Rodents play a significant role in the balance of a terrestrial ecosystem; they are considered prey for many predators like owls and snakes. However, they present a high risk to agriculture (damaging crops) and health. These rodents are the main reservoirs of some vector-borne diseases like leishmaniasis. Meriones shawi (MS) and Psammomys obesus (PO) are the primary Zoonotic cutaneous leishmaniasis (ZCL) reservoirs in the Middle East and North Africa (MENA). A review on the MS and PO at the MENA scale was explored. A database of about 1500 papers was used. 38 sites were investigated as foci for MS and 36 sites for PO, and 83 sites of Phlebotomus papatasi (Pp) in the studied region. An updated map at the regional scale and the trend of the reservoir distribution was carried out using a performing proper density analysis. In this paper, climatic conditions and habitat characteristics of these two reservoirs were reviewed. The association of rodent density with some climatic variables is another aspect explored in a case study from Tunisia in the period 2009-2015 using Pearson correlation. Lastly, the protection and control measures of the reservoir were analyzed. The high concentration of the MS, PO, and Pp can be used as an indicator to identify the high-risk area of leishmaniasis infection.

Monitoring spatiotemporal variation of groundwater level and salinity under land use change using integrated field measurements, GIS, geostatistical, and remote-sensing approach: case study of the Feija aquifer, Middle Draa watershed, Moroccan Sahara.

The cultivation of watermelons has been a fast growing agriculture industry in the arid, desert regions of Morocco, relying on groundwater pumping and transformation of rangelands to farms due to growing demand for the fruit in national and international markets. This study aims to measure the impact of watermelon expansion on groundwater resources in the Feija Basin, which is one of the largest watermelon cultivation areas in Southern Morocco. Field measurements, statistics, Kriging interpolation, and regression methods were used to measure the temporal variations in the groundwater level (GL) and salinity between 2013 and 2018 to determine the correlation between different parameters. Remote sensing data was also used to monitor the watermelon cultivation expansion. Results show a rapid expansion of agricultural areas from just 185.11 ha in 2007 to 2560.1 ha in 2018. The groundwater level declined rapidly by about 10 m below ground level during the 5 years of the study period. Additionally, the decline was accompanied by a significant increase in electrical conductivity (salinity) values over the same time interval from 1077.55 to 1211.9 µS/cm. As a consequence of the continuous overexploitation and unsustainable management, a lot of wells have run dry and there have been drinking water shortages in the city of Zagora, the closest city nearby. Results can help target efforts to improve the implementation of conservation strategies to ensure the sustainability of water use and food production in this region of Morocco.

Eco-epidemiological aspects of Zoonotic cutaneous leishmaniasis in Ouarzazate Province, Morocco.

Some epidemiological and ecological aspects of Zoonotic cutaneous leishmaniasis (ZCL) in Ouarzazate province, southern Morocco, were explored with the objective of analyzing ZCL distribution and associated ecological factors. Information on cutaneous leishmaniasis patients attending the local health centers of Ouarzazate during the period 2002-2009 was gathered and compiled. Urban, peri-urban, rural origin, precipitation, wind speed, temperature, water irrigation, dam volume, and altitude were studied. The findings show that the disease affected 5405 person during this period; the major part was found in the municipalities near both oases (desert oasis) and water resources, with a high concentration of cases in the peri-urban area. The highest percentage of cases was recorded mainly in September. Considerable associations were found between relative humidity and wind speed with ZCL occurrence. A large number of cases were recorded in areas with altitude ranging from 800 to 2000 m.a.s.l. and spatial precipitation from 15 to 150 mm. The statistical analysis showed a strong association between water storage volume and water irrigation with the annual ZCL occurrence recorded in the downstream area (Zagora province). The results will lead us to understand ZCL risk areas for effective control. Further work is needed mainly for gathering these variables in one single and simplest model.

Seasonal Distribution of Phlebotomus papatasi, Vector of Zoonotic Cutaneous Leishmaniasis.

PURPOSE: The activity of Phlebotomus papatasi Scopoli, a vector of cutaneous leishmaniasis, is known to be seasonal, but the information describing these patterns is sparse in time and space. The purpose of his paper is to conduct a meta-analysis to depict the seasonality of P. papatasi at the global scale. METHODS: The current paper uses data from a collection of 1200 scientific papers, where 300 are about the vector and 36 include monthly data (of 61 sites) of the P. papatasi from 15 countries published from 1994 to 2017. RESULTS: The activity peaked mainly in dry periods in all explored sites. A map of seasonal distribution depicted a peak activity in August, followed by September. Geographically (geographic preference), August and September at the latitude 33° showed the highest abundance at a global scale. Concerning the latitude P. papatasi distribution, the high number is localized between 27° and 35°. However, the high number of this species according to the longitude is localized between - 4° and 58°, which shows a high interval of activity. Locally, for the habitat preference, the findings show a preference of this vector to indoor than to outdoor. CONCLUSIONS: All these results can be helpful in identifying the period and sites of a future potential risk of leishmaniasis. This is the first attempt at the update of the vector activity both at global and local scale.