Monkeypox is an emerging infectious disease, which has a clinical presentation similar to smallpox. In the two past decades, Central Africa has seen an increase in the frequency of cases, with many ...monkeypox virus (MPXV) isolates detected in the Democratic Republic of Congo (DRC) and the Central African Republic (CAR). To date, no complete MPXV viral genome has been published from the human cases identified in the CAR. The objective of this study was to sequence the full genome of 10 MPXV isolates collected during the CAR epidemics between 2001 and 2018 in order to determine their phylogenetic relationships among MPXV lineages previously described in Central Africa and West Africa. Our phylogenetic results indicate that the 10 CAR isolates belong to three lineages closely related to those found in DRC. The phylogenetic pattern shows that all of them emerged in the rainforest block of the Congo Basin. Since most human index cases in CAR occurred at the northern edge of western and eastern rainforests, transmissions from wild animals living in the rainforest is the most probable hypothesis. In addition, molecular dating estimates suggest that periods of intense political instability resulting in population movements within the country often associated also with increased poverty may have led to more frequent contact with host wild animals. The CAR socio-economic situation, armed conflicts and ecological disturbances will likely incite populations to interact more and more with wild animals and thus increase the risk of zoonotic spillover.
Arboviral infections are a public health concern and an escalating problem worldwide. Estimating the burden of these diseases represents a major challenge that is complicated by the large number of ...unapparent infections, especially those of dengue fever. Serological surveys are thus required to identify the distribution of these diseases and measure their impact. Therefore, we undertook a scoping review of the literature to describe and summarize epidemiological practices, findings and insights related to seroprevalence studies of dengue, chikungunya and Zika virus, which have rapidly expanded across the globe in recent years.
Relevant studies were retrieved through a literature search of MEDLINE, WHOLIS, Lilacs, SciELO and Scopus (2000 to 2018). In total, 1389 publications were identified. Studies addressing the seroprevalence of dengue, chikungunya and/or Zika written in English or French and meeting the inclusion and exclusion criteria were included. In total, 147 studies were included, from which 185 data points were retrieved, as some studies used several different samples. Most of the studies were exclusively conducted on dengue (66.5%), but 16% were exclusively conducted on chikungunya, and 7 were exclusively conducted on Zika; the remainder were conducted on multiple arboviruses. A wide range of designs were applied, but most studies were conducted in the general population (39%) and in households (41%). Although several assays were used, enzyme-linked immunosorbent assays (ELISAs) were the predominant test used (77%). The temporal distribution of chikungunya studies followed the virus during its rapid expansion since 2004. The results revealed heterogeneity of arboviruses seroprevalence between continents and within a given country for dengue, chikungunya and Zika viruses, ranging from 0 to 100%, 76% and 73% respectively.
Serological surveys provide the most direct measurement for defining the immunity landscape for infectious diseases, but the methodology remains difficult to implement. Overall, dengue, chikungunya and Zika serosurveys followed the expansion of these arboviruses, but there remain gaps in their geographic distribution. This review addresses the challenges for researchers regarding study design biases. Moreover, the development of reliable, rapid and affordable diagnosis tools represents a significant issue concerning the ability of seroprevalence surveys to differentiate infections when multiple viruses co-circulate.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The urban mosquito species Aedes aegypti is the main vector of arboviruses worldwide. Mosquito control with insecticides is the most prevalent method for preventing transmission in the absence of ...effective vaccines and available treatments; however, the extensive use of insecticides has led to the development of resistance in mosquito populations throughout the world, and the number of epidemics caused by arboviruses has increased. Three mosquito lines with different resistance profiles to deltamethrin were isolated in French Guiana, including one with the I1016 knock‐down resistant allele. Significant differences were observed in the cumulative proportion of mosquitoes with a disseminated chikungunya virus infection over time across these lines. In addition, some genes related to resistance (CYP6BB2, CYP6N12, GST2, trypsin) were variably overexpressed in the midgut at 7 days after an infectious bloodmeal in these three lines. Our work shows that vector competence for chikungunya virus varied between Ae. aegypti laboratory lines with different deltamethrin resistance profiles. More accurate verification of the functional association between insecticide resistance and vector competence remains to be demonstrated.
IR03, IR05, and IR13 showing contrasted resistance profiles to deltamethrin (kdr resistance and/ or metabolic resistance);
High infection rates found in all lines and significant differences observed in disseminating step presenting different midgut barriers;
Relative expression level of CYP6BB2, CYP6N12, GST2, trypsin varied amid the midguts of strains used.
Vector competence of Aedes aegypti for chikungunya virus varied amid isofemale lines with different deltamethrin‐resistances
The isolate was, however, susceptible to moxifloxacin. Because parenteral pipericillin and moxifloxacin were not available in our setting, antimicrobial treatment was changed to ampicillin and ...gentamicin on day 5, and the fever resolved by day 9. The bacterium in this patient was resistant to most antibiotics that are recommended as empirical antibiotic therapy for neonatal meningitis,4 which probably accounts for the poor outcomes in this and the previous case.2 Prompt, appropriate antibiotic therapy is the cornerstone of treatment of meningitis.4 Outbreaks due to Elizabethkingia spp could pose a serious health problem because of the lack of measures to prevent nosocomial infections in many African hospitals, high rates of resistance to antibiotics,1 and the shortage of effective parenteral antibiotics.
The invasive Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) was first reported in central Africa in 2000, in Cameroon, with the indigenous mosquito species Ae. aegypti (Diptera: ...Culicidae). Today, this invasive species is present in almost all countries of the region, including the Central African Republic (CAR), where it was first recorded in 2009. As invasive species of mosquitoes can affect the distribution of native species, resulting in new patterns of vectors and concomitant risk for disease, we undertook a comparative study early and late in the wet season in the capital and the main cities of CAR to document infestation and the ecological preferences of the two species. In addition, we determined the probable geographical origin of invasive populations of Ae. albopictus with two mitochondrial DNA genes, COI and ND5. Analysis revealed that Ae. aegypti was more abundant earlier in the wet season and Ae. albopictus in the late wet season. Used tyres were the most heavily colonized productive larval habitats for both species in both seasons. The invasive species Ae. albopictus predominated over the resident species at all sites in which the two species were sympatric. Mitochondrial DNA analysis revealed broad low genetic diversity, confirming recent introduction of Ae. albopictus in CAR. Phylogeographical analysis based on COI polymorphism indicated that the Ae. albopictus haplotype in the CAR population segregated into two lineages, suggesting multiple sources of Ae. albopictus. These data may have important implications for vector control strategies in central Africa.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Aedes albopictus, a mosquito native to Asia, has invaded all five continents during the past three decades. It was reported in central Africa in the 2000s, first in Cameroon, and, since then, has ...colonised almost all countries of the region. The species, originally considered a secondary vector of dengue viruses, has been showed to play a major role in transmission of chikungunya virus in numerous countries, including in the central African region. We review the current spread of Ae. albopictus in central Africa, its larval ecology and its impact on indigenous species such as Ae. aegypti. We explore the potential of Ae. albopictus to affect the epidemiology of emerging or re-emerging arboviruses and discuss the conventional means for its control, while emphasizing the importance of data on its susceptibility to insecticides to cope with potential outbreaks.
Abstract
Background
Since the identification of Zika virus (ZIKV) in Brazil in May 2015, the virus has spread throughout the Americas. However, ZIKV burden in the general population in affected ...countries remains unknown.
Methods
We conducted a general population survey in the different communities of French Guiana through individual interviews and serologic survey during June–October 2017. All serum samples were tested for anti-ZIKV immunoglobulin G antibodies using a recombinant antigen-based SGERPAxMap microsphere immunoassay, and some of them were further evaluated through anti-ZIKV microneutralization tests.
Results
The overall seroprevalence was estimated at 23.3% (95% confidence interval CI, 20.9%–25.9%) among 2697 participants, varying from 0% to 45.6% according to municipalities. ZIKV circulated in a large majority of French Guiana but not in the most isolated forest areas. The proportion of reported symptomatic Zika infection was estimated at 25.5% (95% CI, 20.3%–31.4%) in individuals who tested positive for ZIKV.
Conclusions
This study described a large-scale representative ZIKV seroprevalence study in South America from the recent 2015–2016 Zika epidemic. Our findings reveal that the majority of the population remains susceptible to ZIKV, which could potentially allow future reintroductions of the virus.
This study provides a consistent overview of a large-scale representative Zika virus (ZIKV) seroprevalence study in French Guiana, revealing that the majority of the population remains susceptible to ZIKV, which could potentially allow future reintroductions of the virus.
Febrile jaundice is a common indicator of certain infectious diseases, including hepatitis E. In Cameroon, the yellow fever virus is the only pathogen that is monitored in patients who present with ...this symptom. However, more than 90% of the samples received as part of this surveillance are negative for yellow fever. This study aimed to describe the prevalence and hepatitis E virus (HEV) genotype among yellow fever-negative patients in the Far North and West regions of Cameroon.
In a cross-sectional study, yellow fever surveillance-negative samples collected between January 2021 and January 2023 were retrospectively analyzed. Anti-HEV IgM and IgG antibodies were tested using commercially available ELISA kits. Anti-HEV IgM and/or IgG positive samples were tested for HEV RNA by real-time RT-PCR, followed by nested RT-PCR, sequencing and phylogenetic analysis.
Overall, 121 of the 543 samples (22.3%, 95% CI: 19.0% - 26.0%) were positive for at least one anti-HEV marker. Amongst these, 8.1% (44/543) were positive for anti-HEV IgM, 5.9% (32/543) for anti-HEV IgG, and 8.3% (45/544) for both markers. A total of 15.2% (12/79) samples were positive for HEV RNA real-time RT-PCR and 8 samples were positive for HEV RNA by nested RT-PCR. Phylogenetic analysis showed that the retrieved sequences clustered within HEV genotypes/subtypes 1/1e, 3/3f and 4/4b.
Our results showed that HEV is one of the causes of acute febrile jaundice in patients enrolled in the yellow fever surveillance program in two regions of Cameroon. We described the circulation of three HEV genotypes, including two zoonotic genotypes. Further studies will be important to elucidate the transmission routes of these zoonotic HEV genotypes to humans in Cameroon.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
French Guiana is a territory that has a decades-long history of dengue outbreaks and more recently, in 2014, a chikungunya outbreak. Zika virus (ZIKV) emerged in late 2015 and subsequently led to an ...important outbreak.
A cross-sectional phone survey was conducted among the general population during the outbreak in June 2016 with a total of 1,129 individuals interviewed to assess perceptions, knowledge and behaviors regarding zika infection. The population seemed aware of zika, and perceived the infection as a more serious health threat than other common mosquito-borne diseases. Furthermore, both the perceptions and behaviors related to zika and its prevention were found to vary considerably among different social groups, geographic areas and gender; less educated female participants were found to perceive the disease as more worrisome and were less likely to adopt protective behaviors. Moreover, female population has been particularly responsive to awareness campaigns and rapidly understood the extent of risks associated with ZIKV infection.
These results revealed that ZIKV appeared at the time of the survey as a new health threat that concerns the public more than chikungunya and dengue fever with differences observed among subgroups of population. These results have implications for the development of multifaceted infection control programs, including strategies for prevention and awareness, helping the population to develop an accurate perception of the threat they are facing and encouraging behavior changes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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