A wide range of viruses from different virus families in different geographical areas, may cause immediate or delayed neuropathological changes and neurological manifestations in humans and animals. ...Infection by neurotropic viruses as well as the resulting immune response can irreversibly disrupt the complex structural and functional architecture of the central nervous system, frequently leaving the patient or affected animal with a poor or fatal prognosis. Mechanisms that govern neuropathogenesis and immunopathogenesis of viral infections are highlighted, using examples of well-studied virus infections that are associated with these alterations in different populations throughout the world. A better understanding of the molecular, epidemiological and biological characteristics of these infections and in particular of mechanisms that underlie their clinical manifestations may be expected to provide tools for the development of more effective intervention strategies and treatment regimens.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Acute encephalitis syndrome (AES) differs in its spatio-temporal distribution in Vietnam with the highest incidence seen during the summer months in the northern provinces. AES has multiple ...aetiologies, and the cause remains unknown in many cases. While vector-borne disease such as Japanese encephalitis and dengue virus and non-vector-borne diseases such as influenza and enterovirus show evidence of seasonality, associations with climate variables and the spatio-temporal distribution in Vietnam differs between these. The aim of this study was therefore to understand the spatio-temporal distribution of, and risk factors for AES in Vietnam to help hypothesise the aetiology.
The number of monthly cases per province for AES, meningitis and diseases including dengue fever; influenza-like-illness (ILI); hand, foot, and mouth disease (HFMD); and Streptococcus suis were obtained from the General Department for Preventive Medicine (GDPM) from 1998-2016. Covariates including climate, normalized difference vegetation index (NDVI), elevation, the number of pigs, socio-demographics, JEV vaccination coverage and the number of hospitals were also collected. Spatio-temporal multivariable mixed-effects negative binomial Bayesian models with an outcome of the number of cases of AES, a combination of the covariates and harmonic terms to determine the magnitude of seasonality were developed.
The national monthly incidence of AES declined by 63.3% over the study period. However, incidence increased in some provinces, particularly in the Northwest region. In northern Vietnam, the incidence peaked in the summer months in contrast to the southern provinces where incidence remained relatively constant throughout the year. The incidence of meningitis, ILI and S. suis infection; temperature, relative humidity with no lag, NDVI at a lag of one month, and the number of pigs per 100,000 population were positively associated with the number of cases of AES in all models in which these covariates were included.
The positive correlation of AES with temperature and humidity suggest that a number of cases may be due to vector-borne diseases, suggesting a need to focus on vaccination campaigns. However, further surveillance and research are recommended to investigate other possible aetiologies such as S. suis or Orientia tsutsugamushi.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The live attenuated Japanese encephalitis (JE) vaccine SA14-14-2 has been used in Nepal for catch-up campaigns and is now included in the routine immunisation schedule. Previous studies have shown ...good vaccine efficacy after one dose in districts with a high incidence of JE. The first well-documented dengue outbreak occurred in Nepal in 2006 with ongoing cases now thought to be secondary to migration from India. Previous infection with dengue virus (DENV) partially protects against JE and might also influence serum neutralising antibody titres against JEV. This study aimed to determine whether serum anti-JEV neutralisation titres are: 1. maintained over time since vaccination, 2. vary with historic local JE incidence, and 3. are associated with DENV neutralising antibody levels. We conducted a cross-sectional study in three districts of Nepal: Banke, Rupandehi and Udayapur. Udayapur district had been vaccinated against JE most recently (2009), but had been the focus of only one campaign, compared with two in Banke and three in Rupandehi. Participants answered a short questionnaire and serum was assayed for anti-JEV and anti-DENV IgM and IgG (by ELISA) and 50% plaque reduction neutralisation titres (PRNT50) against JEV and DENV serotypes 1-4. A titre of ≥1:10 was considered seropositive to the respective virus. JEV neutralising antibody seroprevalence (PRNT50 ≥ 1:10) was 81% in Banke and Rupandehi, but only 41% in Udayapur, despite this district being vaccinated more recently. Sensitivity of ELISA for both anti-JEV and anti-DENV antibodies was low compared with PRNT50. DENV neutralising antibody correlated with the JEV PRNT50 ≥1:10, though the effect was modest. IgM (indicating recent infection) against both viruses was detected in a small number of participants. We also show that DENV IgM is present in Nepali subjects who have not travelled to India, suggesting that DENV may have become established in Nepal. We therefore propose that further JE vaccine campaigns should be considered in Udayapur district, and similar areas that have had fewer vaccination campaigns.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
An estimated 73% of emerging infections are zoonotic in origin, with animal contact and encroachment on their habitats increasing the risk of spill-over events. In Vietnam, close exposure to a wide ...range of animals and animal products can lead to acquisition of zoonotic pathogens, a number of which cause central nervous system (CNS) infections. However, studies show the aetiology of CNS infections remains unknown in around half of cases. We used samples and data from hospitalised patients with CNS infections, enrolled into the Vietnam Initiative on Zoonotic Infections multicentre study, to determine the association between aetiology and animal contact including those in whom the cause was unknown. Among 933 patients, a pathogen or an antibody response to it was identified in 291 (31.2%, 95% CI 28.3–34.3%). The most common pathogens were
Streptococcus suis
(
n
= 91 (9.8%, 8.0–11.9%)) and Japanese encephalitis virus (JEV) (
n
= 72 (7.7%, 6.1–9.7%)). Commonly reported animal contact included keeping, raising or handling (
n
= 364 (39.0%, 35.9–42.2%)) and handling, cooking or consuming raw meat, blood or viscera in the 2 weeks prior to symptom onset (
n
= 371 (39.8%, 36.6–43.0%)), with the latter most commonly from pigs (
n
= 343 (36.9%, 33.8–40.1%). There was no association between an unknown aetiology and exposure to animals in a multivariate logistic regression. Further testing for unknown or undetected pathogens may increase diagnostic yield, however, given the high proportion of zoonotic pathogens and the presence of risk factors, increasing public awareness about zoonoses and preventive measures can be considered.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Outbreaks of histoplasmosis have been increasingly reported in association with travel to endemic areas. Multiple outbreaks have been reported following travel to the Americas, but reports of ...pulmonary histoplasmosis in short-term immunocompetent travelers to Africa are rare.
A biology student was referred to our unit with suspected pulmonary histoplasmosis following her return from a field trip in the Ugandan rainforest. The patient informed us that several of her multinational student colleagues on the same expedition had developed a similar illness. Using an alert in ProMED-mail and a questionnaire forwarded to each of the symptomatic students, we accumulated data on the other cases involved in this apparent outbreak of pulmonary histoplasmosis.
Thirteen of 24 students developed respiratory symptoms following the expedition. Chest X-ray appearances were often suggestive of miliary tuberculosis but in most cases a final diagnosis of histoplasmosis was made (confirmed with serology in five cases, clinically diagnosed in six, and retrospectively suspected in two). Detailed questioning indicated that the likely source was a large hollow bat-infested tree within the rainforest.
This is an unusual outbreak of histoplasmosis following short-term travel to Africa. Pulmonary histoplasmosis should always be considered in the differential diagnosis of an acute febrile respiratory illness in travelers returning from endemic areas or reporting activities suggesting exposure.
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BFBNIB, FZAB, GIS, IJS, KILJ, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Utilization of ultrasound in medical inpatients in Malawi Brindle, Hannah E.; Allain, Theresa J.; Kampondeni, Sam ...
Transactions of the Royal Society of Tropical Medicine and Hygiene,
07/2013, Volume:
107, Issue:
7
Journal Article
Peer reviewed
Open access
Background
Ultrasound utilization studies in the developing world are important to support appropriate use.
Methods
A prospective, cross-sectional study in the medical wards at Queen Elizabeth ...Central Hospital, Blantyre, Malawi, was performed which aimed to assess referrals, reports and usefulness of scans to develop local recommendations. The primary outcome of a 'useful scan' was based on scan results and utilization of the report. Indication, quality of requests and reports, and operator were documented. Recommendations for request and report writing were developed.
Results
During 28 April-1 June 2011, 96 scans were analysed of which 66 (69%) were useful. Scans were not useful when the report was non-diagnostic, not documented or not acted upon. Seventy-eight scans (82%) were requested without prior laboratory investigations. A working diagnosis of a pericardial effusion was significantly associated with a useful scan (p = 0.01) as was a medical history of HIV (p ≤ 0.001). The quality of requests and reports in terms of clinical information was moderate or poor in 73% and 33% of cases respectively. Scans by clinicians were at greater odds (OR = 4.0, p = 0.01) of being useful compared with those by radiology technicians.
Conclusion
Despite the majority of ultrasound scans being useful, underutilization and non-useful scans were common, indicating the need to identify appropriate indications and develop relevant guidance and training.
Low population Japanese encephalitis virus Gurung, Santosh; Dixit, Sameer; Solomon, Tom ...
PLoS neglected tropical diseases,
04/2019, Volume:
13, Issue:
4
Journal Article
Peer reviewed
The live attenuated Japanese encephalitis (JE) vaccine SA14-14-2 has been used in Nepal for catch-up campaigns and is now included in the routine immunisation schedule. Previous studies have shown ...good vaccine efficacy after one dose in districts with a high incidence of JE. The first well-documented dengue outbreak occurred in Nepal in 2006 with ongoing cases now thought to be secondary to migration from India. Previous infection with dengue virus (DENV) partially protects against JE and might also influence serum neutralising antibody titres against JEV. This study aimed to determine whether serum anti-JEV neutralisation titres are: 1. maintained over time since vaccination, 2. vary with historic local JE incidence, and 3. are associated with DENV neutralising antibody levels. We conducted a cross-sectional study in three districts of Nepal: Banke, Rupandehi and Udayapur. Udayapur district had been vaccinated against JE most recently (2009), but had been the focus of only one campaign, compared with two in Banke and three in Rupandehi. Participants answered a short questionnaire and serum was assayed for anti-JEV and anti-DENV IgM and IgG (by ELISA) and 50% plaque reduction neutralisation titres (PRNT.sub.50) against JEV and DENV serotypes 1-4. A titre of greater than or equal to1:10 was considered seropositive to the respective virus. JEV neutralising antibody seroprevalence (PRNT.sub.50 greater than or equal to 1:10) was 81% in Banke and Rupandehi, but only 41% in Udayapur, despite this district being vaccinated more recently. Sensitivity of ELISA for both anti-JEV and anti-DENV antibodies was low compared with PRNT.sub.50. DENV neutralising antibody correlated with the JEV PRNT.sub.50 greater than or equal to1:10, though the effect was modest. IgM (indicating recent infection) against both viruses was detected in a small number of participants. We also show that DENV IgM is present in Nepali subjects who have not travelled to India, suggesting that DENV may have become established in Nepal. We therefore propose that further JE vaccine campaigns should be considered in Udayapur district, and similar areas that have had fewer vaccination campaigns.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background Outbreaks of histoplasmosis have been increasingly reported in association with travel to endemic areas. Multiple outbreaks have been reported following travel to the Americas, but reports ...of pulmonary histoplasmosis in short-term immunocompetent travelers to Africa are rare. Methods A biology student was referred to our unit with suspected pulmonary histoplasmosis following her return from a field trip in the Ugandan rainforest. The patient informed us that several of her multinational student colleagues on the same expedition had developed a similar illness. Using an alert in ProMED-mail and a questionnaire forwarded to each of the symptomatic students, we accumulated data on the other cases involved in this apparent outbreak of pulmonary histoplasmosis. Results Thirteen of 24 students developed respiratory symptoms following the expedition. Chest X-ray appearances were often suggestive of miliary tuberculosis but in most cases a final diagnosis of histoplasmosis was made (confirmed with serology in five cases, clinically diagnosed in six, and retrospectively suspected in two). Detailed questioning indicated that the likely source was a large hollow bat-infested tree within the rainforest. Conclusions This is an unusual outbreak of histoplasmosis following short-term travel to Africa. Pulmonary histoplasmosis should always be considered in the differential diagnosis of an acute febrile respiratory illness in travelers returning from endemic areas or reporting activities suggesting exposure. PUBLICATION ABSTRACT
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BFBNIB, FZAB, GIS, IJS, KILJ, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
During the 2018–2020 Ebola virus disease outbreak in Democratic Republic of the Congo, a phase 3 trial of the Ad26.ZEBOV, MVA-BN-Filo Ebola vaccine (DRC-EB-001) commenced in Goma, with participants ...being offered the two-dose regimen given 56 days apart. Suspension of trial activities in 2020 due to the COVID-19 pandemic led to some participants receiving a late dose 2 outside the planned interval. Blood samples were collected from adults, adolescents, and children prior to their delayed dose 2 vaccination and 21 days after, and tested for IgG binding antibodies against Ebola virus glycoprotein using the Filovirus Animal Nonclinical Group (FANG) ELISA. Results from 133 participants showed a median two-dose interval of 9.3 months. The pre-dose 2 antibody geometric mean concentration (GMC) was 217 ELISA Units (EU)/mL (95% CI 157; 301) in adults, 378 EU/mL (281; 510) in adolescents, and 558 EU/mL (471; 661) in children. At 21 days post-dose 2, the GMC increased to 22,194 EU/mL (16,726; 29,449) in adults, 37,896 EU/mL (29,985; 47,893) in adolescents, and 34,652 EU/mL (27,906; 43,028) in children. Participants receiving a delayed dose 2 had a higher GMC at 21 days post-dose 2 than those who received a standard 56-day regimen in other African trials, but similar to those who received the regimen with an extended interval.
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