New insights on malaria
The New microbiologica,
04/2022, Letnik:
45, Številka:
2
Journal Article
Recenzirano
Malaria is long known as a deadly vector borne infection, caused by five parasite species of the coccidian genus Plasmodia that are present in as many as 85 countries. Despite significant progresses ...have been achieved to control the infection by early diagnosis and artemisinin combination treatment, insecticide-treated nets and indoor residual spraying, malaria still represents a major public health issue in many endemic low-income countries. New diagnostic tools of higher sensitivity and specificity are now available for use in endemic countries to better guide diagnosis and treatment. In particular, highly sensitive rapid antigenic tests are now available and the loop-mediated isothermal amplification is a very promising and highly sensitive diagnostic tool. After 2015, decreasing morbidity and mortality trends have been stagnating because of limited funding, emergence of parasite and vector resistance to drugs and insecticides respectively and, recently, by the disrupting effect of COVID-19 pandemic. The incomplete knowledge of the complex immunity of malaria infection has slowed the development of an effective vaccine. However, in 2021, the RTS-S vaccine, however of suboptimal protective efficacy, has been made available for routine use in children above 5 months of age. Population movements has increased the chance of observing imported malaria in non-endemic areas, where malaria competent vectors may still exist.
Terminology in schistosomiasis is not harmonised, generating misunderstanding in data interpretation and clinical descriptions. This study aimed to achieve consensus on definitions of clinical ...aspects of schistosomiasis in migrants and returning travellers. We applied the Delphi method. Experts from institutions affiliated with GeoSentinel and TropNet, identified through clinical and scientific criteria, were invited to participate. Five external reviewers revised and pilot-tested the statements. Statements focusing on the definitions of acute or chronic; possible, probable, or confirmed; active; and complicated schistosomiasis were managed through REDCap and replies managed in a blinded manner. Round 1 mapped the definitions used by experts; subsequent rounds were done to reach consensus, or quantify disagreement, on the proposed statements. Data were analysed with percentages, medians, and IQRs of a 5-point Likert scale. The study was terminated on the basis of consensus or stability-related and time-related criteria. 28 clinicians and scientists met the criteria for experts. 25 (89%) of 28 experts replied to Round 1, 18 (64%) of 28 to Round 2, 19 (68%) of 28 to Round 3, and 21 (75%) of 28 to at least two rounds. High-level consensus (79–100% agreement and IQRs ≤1) was reached for all definitions. Consensus definitions will foster harmonised scientific and clinical communication and support future research and development of management guidelines for schistosomiasis.
Among the
family,
is the most notorious genus. Several DNA viruses belonging to this group are known to produce human disease from the life-threatening variola virus (VARV) (the causative agent of ...smallpox), monkeypox virus (MPXV), cowpox virus (CPXV), and vaccinia virus (VACV). These
still remain a public health concern as VACV or CPXV still cause emerging endemic threads, especially in developing countries. MPXV is able to cause sporadic human outbreaks of a smallpox-like zoonotic disease and, in May 2022, hundreds of cases related to MPXV have been reported from more than 30 countries around the globe. At the end of July, monkeypox (MPX) outbreak was even declared a global health emergency by the World Health Organization (WHO). Many aspects remain unclear regarding this outbreak and a deep understanding of
might have crucial and evident implications. During the era in which people under 45 years old are not protected against VACV, the potential use of
as a biological weapon raises global concern considering the rapid spreading of the current MPX outbreak in vulnerable populations. Hence, we review the most recent evidence about phylogenesis, pathogenesis, prevention, and treatment for this concerning disease.
Visceral leishmaniasis (VL) is a parasitic zoonosis caused by
spp. that usually manifests itself in immunocompromised subjects. It is a rare and neglected disease, and it is not endemic in the ...province of Brescia (Italy). Three cases of human VL occurred in Brescia from October to December 2021 in immunocompetent patients. We evaluated the patients looking for signs of underlying immunodeficiencies and conducted further epidemiological evaluations in the province of Brescia without success. An analysis of the sera levels of the main cytokines involved in the immune response to VL was performed. All patients presented a significant augmentation of CXCL-10, CCL-4, and IL-6. The patients tested during the acute phase showed an elevation of IL-1α, IL-5, IL-10, and IL-12, while in the recovery phase, higher levels of TNF-α and IL-7 were detected. Altogether, a predominant activation of the T-helper-2 pathway emerged during the acute phase of the parasite infection, while the cytokines associated with the T-helper-1 pathway were less represented. This imbalanced immune response to the parasite infection might play a crucial role in the development of VL in immunocompetent patients.
Few previous retrospective studies suggest that Plasmodium ovale wallikeri seems to have a longer latency period and produces deeper thrombocytopaenia than Plasmodium ovale curtisi. Prospective ...studies were warranted to better assess interspecies differences.
Patients with imported P. ovale spp. infection diagnosed by thick or thin film, rapid diagnostic test (RDT) or polymerase chain reaction (PCR) were recruited between March 2014 and May 2017. All were confirmed by DNA isolation and classified as P. o. curtisi or P. o. wallikeri using partial sequencing of the ssrRNA gene. Epidemiological, analytical and clinical differences were analysed by statistical methods.
A total of 79 samples (35 P. o. curtisi and 44 P. o. wallikeri) were correctly genotyped. Males predominate in wallikeri group (72.7%), whereas were 48.6% in curtisi group. Conversely, 74.3% of curtisi group were from patients of African ethnicity, whilst 52.3% of Caucasians were infected by P. o. wallikeri. After performing a multivariate analysis, more thrombocytopaenic patients (p = 0.022), a lower number of platelets (p = 0.015), a higher INR value (p = 0.041), and shorter latency in Caucasians (p = 0.034) were significantly seen in P. o. wallikeri. RDT sensitivity was 26.1% in P. o. curtisi and 42.4% in P. o. wallikeri. Nearly 20% of both species were diagnosed only by PCR. Total bilirubin over 3 mg/dL was found in three wallikeri cases. Two patients with curtisi infection had haemoglobin under 7 g/dL, one of them also with icterus. A wallikeri patient suffered from haemophagocytosis. Chemoprophylaxis failed in 14.8% and 35% of curtisi and wallikeri patients, respectively. All treated patients with various anti-malarials which included artesunate recovered. Diabetes mellitus was described in 5 patients (6.32%), 4 patients of wallikeri group and 1 curtisi.
Imported P. o. wallikeri infection may be more frequent in males and Caucasians. Malaria caused by P. o. wallikeri produces more thrombocytopaenia, a higher INR and shorter latency in Caucasians and suggests a more pathogenic species. Severe cases can be seen in both species. Chemoprophylaxis seems less effective in P. ovale spp. infection than in P. falciparum, but any anti-malarial drug is effective as initial treatment. Diabetes mellitus could be a risk factor for P. ovale spp. infection.
Rickettsia felis is an emerging spotted fever group pathogen that may be responsible for potentially life-threatening infections. A cosmopolitan distribution has been postulated though most human ...cases were observed in Africa and the Americas. We report an imported case from Nepal that occurred in an Italian tourist who presented with a 1-week history of fever, headache, nausea, vomiting, and a mild maculopapular rash 14 days after return.
Italy provides a free voluntary serological screening for toxoplasmosis in pregnancy supported by public health system, as there is an estimated congenital toxoplasmosis rate of 1-2/10,000. The aim ...of this study was to make an inventory of diagnostic and therapeutic protocols in use in Italy in the absence of a national guideline. A semistructured questionnaire was distributed to AMCLI (Italian Association of Clinical Microbiologists) members who were asked to involve other specialists to fill in the form. Data from 26 centers show: a) a general use of the IgG avidity test to solve diagnosis in IgG/IgM positive, pregnant women; b) a widespread attitude to spyramicin antenatal treatment in suspected, unconfirmed maternal infection; c) avoidance of invasive antenatal diagnosis only in suspected early or late (>24 weeks), even confirmed, maternal infection d) fetal diagnosis performed by PCR assays on amniotic fluid; e) variability of both indications and dosage of pyrimethamine-sulfadiazine (P-S) as fetal treatment; f) use of comparative mother and newborn IgG/IgM Immuneblot in most centers; g) no diagnostic tests performed on placenta and cord blood; h) spyramicin is no longer used in congenital infections; i) no P-S-based treatment for children at high risk of congenital infection (late maternal infection) in the absence of diagnosis. As there is the opportunity to test pregnant women for Toxoplasma gondii infection in Italy free of charge, standardized diagnostic and therapeutic national guidelines would focus on a more uniform approach.
West Nile virus (WNV) infection is a seasonal arbovirosis with the potential to cause severe neurological disease. Outcomes of the infection from WNV depend on viral factors (e.g., lineage) and ...host-intrinsic factors (e.g., age, sex, immunocompromising conditions). Immunity is essential to control the infection but may also prove detrimental to the host. Indeed, the persistence of high levels of pro-inflammatory cytokines and chemokines is associated with the development of blood-brain barrier (BBB) damage. Due to the importance of the inflammatory processes in the development of West Nile neuroinvasive disease (WNND), we reviewed the available literature on the subject.
According to the 2020 updated PRISMA guidelines, all peer-reviewed articles regarding the inflammatory response associated with WNND were included.
One hundred and thirty-six articles were included in the data analysis and sorted into three groups (in vitro on-cell cultures, in vivo in animals, and in humans). The main cytokines found to be increased during WNND were IL-6 and TNF-α. We highlighted the generally small quantity and heterogeneity of information about the inflammatory patterns associated with WNND.
Further studies are needed to understand the pathogenesis of WNND and to investigate the extent and the way the host inflammatory response either helps in controlling the infection or in worsening the outcomes. This might prove useful both for the development of target therapies and for the development of molecular markers allowing early identification of patients displaying an inflammatory response that puts them at a higher risk of developing neuroinvasive disease and who might thus benefit from early antiviral therapies.
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