Serological Evidence of Hepatitis E Virus Infection in Semi-Domesticated Eurasian Tundra Reindeer (Rangifer tarandus tarandus) in Norway

Hepatitis E virus (HEV) is a common cause of viral hepatitis in humans. In developing countries, HEV-infections seem to be mainly associated with pigs, but other animal species may be involved in viral transmission. Recently, anti-HEV antibodies were detected in Norwegian wild reindeer. Here, we investigated anti-HEV seroprevalence in Norwegian semi-domesticated reindeer, animals in closer contact with humans than their wild counterparts. Blood samples (n = 516) were obtained from eight reindeer herds during the period 2013–2017 and analysed with a commercial enzyme-linked immunosorbent assay designed for detecting anti-HEV antibodies in livestock. Antibodies were found in all herds and for all sampling seasons. The overall seroprevalence was 15.7% (81/516), with adults showing a slightly higher seroprevalence (18.0%, 46/256) than calves (13.5%, 35/260, p = 0.11). The seroprevalence was not influenced by gender or latitude, and there was no temporal trend (p > 0.15). A positive association between the presence of anti-HEV antibodies and antibodies against alphaherpesvirus and pestivirus, detected in a previous screening, was found (p < 0.05). We conclude that Norwegian semi-domesticated reindeer are exposed to HEV or an antigenically similar virus. Whether the virus is affecting reindeer health or infects humans and poses a threat for human health remains unknown and warrants further investigations.

Extension of Sylvatic Circulation of African Swine Fever Virus in Extralimital Warthogs in South Africa

Sylvatic circulation of African swine fever virus (ASFV) in warthogs and Ornithodoros ticks that live in warthog burrows historically occurred in northern South Africa. Outbreaks of the disease in domestic pigs originated in this region. A controlled area was declared in the north in 1935 and regulations were implemented to prevent transfer of potentially infected suids or products to the rest of the country. However, over the past six decades, warthogs have been widely translocated to the south where the extralimital animals have flourished to become an invasive species. Since 2016, there have been outbreaks of ASF in pigs outside the controlled area that cannot be linked to transfer of infected animals or products from the north. An investigation in 2008–2012 revealed that the presence of Ornithodoros ticks and ASFV in warthog burrows extended marginally across the boundary of the controlled area. We found serological evidence of ASFV circulation in extralimital warthogs further south in the central part of the country.

Serological Evidence of Zika Virus Infection in Febrile Patients and Healthy Blood Donors in Sabah, Malaysian Borneo, 2017–2018

Several Zika virus (ZIKV) seroprevalence studies have been conducted in Africa, Asia, Oceania, the Americas, and the Caribbean. However, studies on ZIKV seroprevalence are limited in Malaysia though several studies have shown that the disease is endemic in the Malaysian state of Sabah. To evaluate the seroprevalence of ZIKV infection, 818 serum samples were collected from febrile patients and healthy blood donors from the Kudat and Kota Kinabalu districts in Sabah from 2017 to 2018. They were screened for ZIKV infection by IgM and IgG ELISA, and positive ZIKV IgM samples were subjected to a 90% neutralization test for confirmation. Twenty-four (6% [95% CI 4 to 8]) confirmed and two (0.5% [95% CI 0.13 to 1.8]) probable ZIKV infections were detected among 400 febrile illness patients. Of 418 healthy blood donor samples, six (1.4% [95% CI 0.65 to 3]) were determined as confirmed ZIKV infections and six (1.4% [95% CI 0.65 to 3]) indicated probable ZIKV infection. This is the first study on the seroprevalence of ZIKV infections among patients and healthy blood donors in Sabah. Compared with previous studies in Malaysia, this study shows that the incidence of ZIKV infection has increased. It also suggests that a sero-surveillance system is essential to determine the circulation of ZIKV in Sabah, Malaysia.

Durability of antibody responses and frequency of clinical and subclinical SARS-CoV-2 infection six months after BNT162b2 COVID-19 vaccination in healthcare workers

Antibodies against SARS-CoV-2 decay but persist six months post-vaccination, with lower levels of neutralizing titers against Delta than wild-type. Only 2 of 227 vaccinated healthcare workers experienced outpatient symptomatic breakthrough infections despite 59 of 227 exhibiting serological evidence of exposure to SARS-CoV-2 as defined by development of anti-nucleocapsid protein antibodies.

Evaluation of Thyroid Dysfunction in Adult Patients of Celiac Disease

OBJECTIVES: To assess free thyroxine (fT4), thyroid stimulating hormone (TSH), and anti thyroid peroxidase antibodies (anti TPO abs) in adult Celiac disease patients and non-celiac controls and to find out any statistically significant difference in their corresponding means between the two groups. METHODOLOGY: The study design was analytical cross sectional. Sixty adult patients of celiac disease (CD) and 30 apparently healthy non-celiac adults were included in the study. CD patients had earlier been diagnosed by elevated levels of serological evidence of elevated (greater than 15X ULN) anti tissue transglutaminase (TTG) (IgA class) antibodies. CD was ruled out in the control group by normal levels of the antibodies. TSH, fT4 and anti TPO abs were obtained from all individuals of CD patient and control groups. RESULTS: Mean age of Celiac disease in patients was 23.85±5.43 years. Mean age of individuals in the control group was 24.26±5.55 years. Statistically significant difference in mean TSH and anti-TPO abs levels between the CD patient group and control group (p values of 0.03 and 0.038, respectively) was present. No statistically significant difference was seen between mean fT4 of patients and control group (p=0.74). Subclinical and overt hypothyroidism was present in 10% and 5% of CD patients, while anti TPO abs was positive in 16.6% of CD patients. CONCLUSION: There is a considerably high prevalence of subclinical and overt hypothyroidism as well as serological evidence of thyroid dysfunction in adult patients of CD.

The emergence of Dengue Fever in Sheikhupura, Pakistan: its seroprevalence and risk factors assessment during 2014-2017

Introduction: District Sheikhupura encountered its first dengue outbreak in 2014 but lacked serological evidence and reports of risk factors associated with it. To assess this, a hospital-based study was conducted from January 2014 to December 2017. Methodology: Blood from 333 participants was collected, the serum obtained was tested for IgG and IgM antibodies against DENV using a commercially available ELISA kit. Results: The results showed that out of all (n= 333) samples tested, 120 were turned up positive for DENV, making an overall prevalence of 36%. Of the 120 confirmed cases, 55% (n = 66) were recorded in 2014, 10% (n = 12) in 2015, 27.5% (n = 33) in 2016, and 7.5% (n = 9) in 2017. It was found that 68.3% (n = 82) were male and 31.7% (n = 38) were female, with 61% (n = 74) patients aged between 11-30 years. The highest prevalence of infection, 94.2% (n = 113), was noted after the rainy season. During the study, the highest number of cases appeared in Ferozewala Tehsil. The factors age, gender, and season were found statistically significant with the prevalence of infection (p < 0.05). Conclusions: The study is the first report on the detection of dengue in the Sheikhupura district. The survey anticipated its geographical expansion, determined associated risk factors, and suggests active disease surveillance in the area.

Modelling bluetongue risk in Kazakhstan

Background Bluetongue is a serious disease of ruminants caused by the bluetongue virus (BTV). BTV is transmitted by biting midges (Culicoides spp.). Serological evidence from livestock and the presence of at least one competent vector species of Culicoides suggests that transmission of BTV is possible and may have occurred in Kazakhstan. Methods We estimated the risk of transmission using a mathematical model of the reproduction number R0 for bluetongue. This model depends on livestock density and climatic factors which affect vector density. Data on climate and livestock numbers from the 2466 local communities were used. This, together with previously published model parameters, was used to estimate R0 for each month of the year. We plotted the results on isopleth maps of Kazakhstan using interpolation to smooth the irregular data. We also mapped the estimated proportion of the population requiring vaccination to prevent outbreaks of bluetongue. Results The results suggest that transmission of bluetongue in Kazakhstan is not possible in the winter from October to March. Assuming there are vector-competent species of Culicoides endemic in Kazakhstan, then low levels of risk first appear in the south of Kazakhstan in April before spreading north and intensifying, reaching maximum levels in northern Kazakhstan in July. The risk declined in September and had disappeared by October. Conclusion These results should aid in surveillance efforts for the detection and control of bluetongue in Kazakhstan by indicating where and when outbreaks of bluetongue are most likely to occur. The results also indicate where vaccination efforts should be focussed to prevent outbreaks of disease. Graphical abstract