-
PLoS Neglected Tropical Diseases Jan 2022Phlebotomine sand flies (Diptera: Psychodidae) are important vectors of various human and animal pathogens such as Bartonella bacilliformis, Phlebovirus, and parasitic...
BACKGROUND
Phlebotomine sand flies (Diptera: Psychodidae) are important vectors of various human and animal pathogens such as Bartonella bacilliformis, Phlebovirus, and parasitic protozoa of the genus Leishmania, causative agent of leishmaniases that account among most significant vector-borne diseases. The Maghreb countries Mauritania, Morocco, Algeria, Tunisia, and Libya occupy a vast area of North Africa and belong to most affected regions by these diseases. Locally varying climatic and ecological conditions support diverse sand fly fauna that includes many proven or suspected vectors. The aim of this review is to summarize often fragmented information and to provide an updated list of sand fly species of the Maghreb region with illustration of species-specific morphological features and maps of their reported distribution.
MATERIALS AND METHODS
The literature search focused on scholar databases to review information on the sand fly species distribution and their role in the disease transmissions in Mauritania, Morocco, Algeria, Tunisia, and Libya, surveying sources from the period between 1900 and 2020. Reported distribution of each species was collated using Google Earth, and distribution maps were drawn using ArcGIS software. Morphological illustrations were compiled from various published sources.
RESULTS AND CONCLUSIONS
In total, 32 species of the genera Phlebotomus (Ph.) and Sergentomyia (Se.) were reported in the Maghreb region (15 from Libya, 18 from Tunisia, 23 from Morocco, 24 from Algeria, and 9 from Mauritania). Phlebotomus mariae and Se. africana subsp. asiatica were recorded only in Morocco, Ph. mascitti, Se. hirtus, and Se. tiberiadis only in Algeria, whereas Ph. duboscqi, Se. dubia, Se. africana africana, Se. lesleyae, Se. magna, and Se. freetownensis were reported only from Mauritania. Our review has updated and summarized the geographic distribution of 26 species reported so far in Morocco, Algeria, Tunisia, and Libya, excluding Mauritania from a detailed analysis due to the unavailability of accurate distribution data. In addition, morphological differences important for species identification are summarized with particular attention to closely related species such as Ph. papatasi and Ph. bergeroti, Ph. chabaudi, and Ph. riouxi, and Se. christophersi and Se. clydei.
Topics: Africa, Northern; Animals; Communicable Diseases; Humans; Insect Vectors; Psychodidae
PubMed: 34990451
DOI: 10.1371/journal.pntd.0009952 -
PLoS Neglected Tropical Diseases Jan 2022Rift Valley fever virus (RVFV) is a lethal threat to humans and livestock in many parts of Africa, the Arabian Peninsula, and the Indian Ocean. This systematic review's...
BACKGROUND
Rift Valley fever virus (RVFV) is a lethal threat to humans and livestock in many parts of Africa, the Arabian Peninsula, and the Indian Ocean. This systematic review's objective was to consolidate understanding of RVFV epidemiology during 1999-2021 and highlight knowledge gaps relevant to plans for human vaccine trials.
METHODOLOGY/PRINCIPAL FINDINGS
The review is registered with PROSPERO (CRD42020221622). Reports of RVFV infection or exposure among humans, animals, and/or vectors in Africa, the Arabian Peninsula, and the Indian Ocean during the period January 1999 to June 2021 were eligible for inclusion. Online databases were searched for publications, and supplemental materials were recovered from official reports and research colleagues. Exposures were classified into five groups: 1) acute human RVF cases, 2) acute animal cases, 3) human RVFV sero-surveys, 4) animal sero-surveys, and 5) arthropod infections. Human risk factors, circulating RVFV lineages, and surveillance methods were also tabulated. In meta-analysis of risks, summary odds ratios were computed using random-effects modeling. 1104 unique human or animal RVFV transmission events were reported in 39 countries during 1999-2021. Outbreaks among humans or animals occurred at rates of 5.8/year and 12.4/year, respectively, with Mauritania, Madagascar, Kenya, South Africa, and Sudan having the most human outbreak years. Men had greater odds of RVFV infection than women, and animal contact, butchering, milking, and handling aborted material were significantly associated with greater odds of exposure. Animal infection risk was linked to location, proximity to water, and exposure to other herds or wildlife. RVFV was detected in a variety of mosquito vectors during interepidemic periods, confirming ongoing transmission.
CONCLUSIONS/SIGNIFICANCE
With broad variability in surveillance, case finding, survey design, and RVFV case confirmation, combined with uncertainty about populations-at-risk, there were inconsistent results from location to location. However, it was evident that RVFV transmission is expanding its range and frequency. Gaps assessment indicated the need to harmonize human and animal surveillance and improve diagnostics and genotyping. Given the frequency of RVFV outbreaks, human vaccination has strong potential to mitigate the impact of this now widely endemic disease.
Topics: Global Health; Humans; Rift Valley Fever; Rift Valley fever virus; Vaccination; Viral Vaccines
PubMed: 35073355
DOI: 10.1371/journal.pntd.0009852 -
Acta Tropica Aug 2022Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infection disease that is deadly if left untreated. Identification of potential risk factors with... (Meta-Analysis)
Meta-Analysis
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infection disease that is deadly if left untreated. Identification of potential risk factors with prognosis value may help to focus clinical management and reduce case fatality. However, information about these factors is conflicting and scattered. In this study, documents on SFTS were collected by searching PubMed, Web of Science, Chinese National Knowledge Infrastructure (CNKI) and Chinese Wan Fang Database through 12 January 2021. Meta-analysis was performed by using Stata and Review Manage software. 29 studies were included, involving 3011 participants with 38 clinical symptoms. The following factors were strongly (OR>5) and significantly (P-value<0.05) associated with mortality: hematemesis (OR=13.73), slurred speech (OR=5.05), disturbance of consciousness (OR=9.20), coma (OR=47.84), disseminated intravascular coagulation (OR=11.79), multiple organ dysfunction (OR=21.30), shock (OR=8.20) and acute kidney injury (OR=6.22). Non-specific symptoms, underlying diseases, respiratory symptoms and gastrointestinal symptoms were not associated with mortality of SFTS patients. Neurological symptoms and severe complications significantly increasing the death risk of SFTS cases can be identified by medical staff in resource-constrained settings and should be considered as core factors in future researchers that aim at improving the prognosis of SFTS patients.
Topics: China; Communicable Diseases, Emerging; Fever; Humans; Phlebovirus; Severe Fever with Thrombocytopenia Syndrome; Thrombocytopenia
PubMed: 35461803
DOI: 10.1016/j.actatropica.2022.106481 -
International Journal of Environmental... Feb 2022Severe fever with thrombocytopenia syndrome (SFTS) is an infection mediated by ticks and has been reported to have a high mortality rate in Japan. At our hospital, we... (Review)
Review
Severe fever with thrombocytopenia syndrome (SFTS) is an infection mediated by ticks and has been reported to have a high mortality rate in Japan. At our hospital, we reported three cases of SFTS with relatively positive outcomes. We reviewed reports of SFTS cases in Japan to clarify the current state of the disease in Japan, the treatment provided, and its outcome. The Ichushi Web was searched for literature using the following terms as keywords: "SFTS" or "severe fever with thrombocytopenia syndrome". Overall, 174 cases were collected and reviewed. The mean age of patients was 70.69 years old, and the mortality rate was 35%. The dead group was significantly older ( < 0.001) than the alive group, had a significantly shorter period from symptom onset to hospital admission, and experienced significantly more hemorrhage-related and neurological symptoms. Further, the most frequently provided treatment methods were adrenocorticosteroids, antibiotics, and conservative treatment. The low recognition rate of SFTS in Japan might lead to a misdiagnosis or delay in diagnosis and treatment, especially in mild to moderate cases. Medical professionals and citizens who live in areas inhabited by ticks need to be informed about SFTS to appropriately diagnose and manage SFTS cases in Japan in the future.
Topics: Aged; Animals; Bunyaviridae Infections; Humans; Japan; Phlebovirus; Severe Fever with Thrombocytopenia Syndrome; Thrombocytopenia; Ticks
PubMed: 35206459
DOI: 10.3390/ijerph19042271 -
Epidemiology and Infection Sep 2020Severe fever with thrombocytopenia syndrome (SFTS) is a disease with a high case-fatality rate that is caused by infection with the SFTS virus (SFTSV). Five electronic... (Meta-Analysis)
Meta-Analysis
Severe fever with thrombocytopenia syndrome (SFTS) is a disease with a high case-fatality rate that is caused by infection with the SFTS virus (SFTSV). Five electronic databases were systematically searched to identify relevant articles published from 1 January 2011 to 1 December 2019. The pooled rates with 95% confidence interval (CI) were calculated by a fixed-effect or random-effect model analysis. The results showed that 92 articles were included in this meta-analysis. For the confirmed SFTS cases, the case-fatality rate was 0.15 (95% CI 0.11, 0.18). Two hundred and ninety-six of 1384 SFTS patients indicated that they had been bitten by ticks and the biting rate was 0.21 (95% CI 0.16, 0.26). The overall pooled seroprevalence of SFTSV antibodies among the healthy population was 0.04 (95% CI 0.03, 0.05). For the overall seroprevalence of SFTSV in animals, the seroprevalence of SFTSV was 0.25 (95% CI 0.20, 0.29). The infection rate of SFTSV in ticks was 0.08 (95% CI 0.05, 0.11). In conclusion, ticks can serve as transmitting vectors of SFTSVs and reservoir hosts. Animals can be infected by tick bites, and as a reservoir host, SFTSV circulates continuously between animals and ticks in nature. Humans are infected by tick bites and direct contact with patient secretions.
Topics: Animals; Disease Notification; Humans; Phlebovirus; Severe Fever with Thrombocytopenia Syndrome; Tick Bites; Ticks
PubMed: 32993819
DOI: 10.1017/S0950268820002290 -
The Science of the Total Environment Mar 2024Rift valley fever (RVF) is listed as one of prioritized diseases by WHO. This study aims to describe RVF virus' landscape distribution globally, and to insight dynamics...
BACKGROUND
Rift valley fever (RVF) is listed as one of prioritized diseases by WHO. This study aims to describe RVF virus' landscape distribution globally, and to insight dynamics change of its evolution, prevalence, and outbreaks in the process of breaking geographical barriers.
METHODS
A systematic literature review and meta-analyses was conducted to estimate RVF prevalence by hosts using a random-effect model. Molecular clock-based phylogenetic analyses were performed to estimate RVF virus nucleotide substitution rates using nucleotide sequences in NCBI database. RVF virus prevalence, nucleotide substitution rates, and outbreaks were compared before and after breaking geographical barriers twice, respectively.
RESULTS
RVF virus was reported from 26 kinds of hosts covering 48 countries from 1930 to 2022. Since RVF broke geographical barriers, (1) nucleotide substitution rates significantly increased after firstly spreading out of Africa in 2000, (2) prevalence in humans significantly increased from 1.92 % (95 % CI: 0.86-3.25 %) to 3.03 % (95 % CI: 2.09-4.12 %) after it broke Sahara Desert geographical barriers in 1977, and to 5.24 % (95 % CI: 3.81-6.82 %) after 2000, (3) RVF outbreaks in humans and the number of wildlife hosts presented increasing trends. RVF virus spillover may exist between bats and humans, and accelerate viral substitution rates in humans. During outbreaks, the RVF virus substitution rates accelerated in humans. 60.00 % RVF outbreaks occurred 0-2 months after floods and (or) heavy rainfall.
CONCLUSION
RVF has the increasing risk to cause pandemics, and global collaboration on "One Health" is needed to prevent potential pandemics.
Topics: Animals; Humans; Rift Valley fever virus; Prevalence; Phylogeny; Rift Valley Fever; Disease Outbreaks; Nucleotides
PubMed: 38272089
DOI: 10.1016/j.scitotenv.2024.170302 -
Parasites & Vectors Jun 2024Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne zoonosis caused by the SFTS virus (SFTSV). Understanding the prevalence of SFTSV RNA in... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne zoonosis caused by the SFTS virus (SFTSV). Understanding the prevalence of SFTSV RNA in humans, vertebrate hosts and ticks is crucial for SFTS control.
METHODS
A systematic review and meta-analysis were conducted to determine the prevalence of SFTSV RNA in humans, vertebrate hosts and questing ticks. Nine electronic databases were searched for relevant publications, and data on SFTSV RNA prevalence were extracted. Pooled prevalence was estimated using a random effects model. Subgroup analysis and multivariable meta-regression were performed to investigate sources of heterogeneity.
RESULTS
The pooled prevalence of SFTSV RNA in humans was 5.59% (95% confidence interval [CI] 2.78-9.15%) in those in close contact (close contacts) with infected individuals (infected cases) and 0.05% (95% CI 0.00-0.65%) in healthy individuals in endemic areas. The SFTSV infection rates in artiodactyls (5.60%; 95% CI 2.95-8.96%) and carnivores (6.34%; 95% CI 3.27-10.23%) were higher than those in rodents (0.45%; 95% CI 0.00-1.50%). Other animals, such as rabbits, hedgehogs and birds, also played significant roles in SFTSV transmission. The genus Haemaphysalis was the primary transmission vector, with members of Ixodes, Dermacentor, and Amblyomma also identified as potential vectors. The highest pooled prevalence was observed in adult ticks (1.03%; 95% CI 0.35-1.96%), followed by nymphs (0.66%; 95% CI 0.11-1.50%) and larvae (0.01%; 95% CI 0.00-0.46%). The pooled prevalence in ticks collected from endemic areas (1.86%; 95% CI 0.86-3.14%) was higher than that in ticks collected in other regions (0.41%; 95% CI 0.12-0.81%).
CONCLUSIONS
Latent SFTSV infections are present in healthy individuals residing in endemic areas, and close contacts with SFTS cases are at a significantly higher risk of infection. The type of animal is linked to infection rates in vertebrate hosts, while infection rates in ticks are associated with the developmental stage. Further research is needed to investigate the impact of various environmental factors on SFTSV prevalence in vertebrate hosts and ticks.
Topics: Animals; Humans; Phlebovirus; Severe Fever with Thrombocytopenia Syndrome; Ticks; Vertebrates; Prevalence; RNA, Viral
PubMed: 38902842
DOI: 10.1186/s13071-024-06341-2