Sarah K. White

Serologic evidence of exposure to influenza D virus among persons with occupational contact with cattle.

BACKGROUND Influenza D virus (IDV), a novel influenza virus with proposed classification: family Orthomyxoviridae, genus Influenzavirus D, species Influenza D virus, has been associated with influenza-like illness in cattle and swine. More recently, anti-IDV antibodies have also been detected in small ruminants. A seroprevalence of approximately 1.3% has been estimated for the general human population. OBJECTIVES To gain insights on the zoonotic potential of IDV to human adults with occupational exposure to cattle in north central Florida. STUDY A cross-sectional serological study was performed on human serum samples from 35 cattle-exposed and 11 non-cattle-exposed adults to screen for IDV antibodies using hemagglutination inhibition (HI) and microneutralization (MN) assays. RESULTS A seroprevalence of 91% was detected via HI assay, and 97% by MN assay among individuals working with cattle in Florida. Among non-cattle-exposed individuals, seropositivity determined via MN assay (only) was lower (18%). CONCLUSIONS IDV poses a zoonotic risk to cattle-exposed workers, based on detection of high seroprevalence (94-97%). Whereas it is still unknown whether IDV causes disease in humans, our studies indicate that the virus may be an emerging pathogen among cattle-workers.

Equine influenza A(H3N8) virus isolated from Bactrian camel, Mongolia.

Because little is known about the ecology of influenza viruses in camels, 460 nasal swab specimens were collected from healthy (no overt illness) Bactrian camels in Mongolia during 2012. One specimen was positive for influenza A virus (A/camel/Mongolia/335/2012[H3N8]), which is phylogenetically related to equine influenza A(H3N8) viruses and probably represents natural horse-to-camel transmission.

Live poultry market workers are susceptible to both avian and swine influenza viruses, Guangdong Province, China.

Abstract Guangdong Province is recognized for dense populations of humans, pigs, poultry and pets. In order to evaluate the threat of viral infection faced by those working with animals, a cross-sectional, sero-epidemiological study was conducted in Guangdong between December 2013 and January 2014. Individuals working with swine, at poultry farms, or live poultry markets (LPM), and veterinarians, and controls not exposed to animals were enrolled in this study and 11 (4 human, 3 swine, 3 avian, and 1 canine) influenza A viruses were used in hemagglutination inhibition (HI) assays (7 strains) and the cross-reactivity test (9 strains) in which 5 strains were used in both tests. Univariate analysis was performed to identify which variables were significantly associated with seropositivity. Odds ratios (OR) revealed that swine workers had a significantly higher risk of elevated antibodies against A/swine/Guangdong/L6/2009(H1N1), a classical swine virus, and A/swine/Guangdong/SS1/2012(H1N1), a Eurasian avian-like swine virus than non-exposed controls. Poultry farm workers were at a higher risk of infection with avian influenza H7N9 and H9N2. LPM workers were at a higher risk of infection with 3 subtypes of avian influenza, H5N1, H7N9, and H9N2. Interestingly, the OR also indicated that LPM workers were at risk of H1N1 swine influenza virus infection, perhaps due to the presence of pigs in the LPM. While partial confounding by cross-reactive antibodies against human viruses or vaccines cannot be ruled out, our data suggests that animal exposed people as are more likely to have antibodies against animal influenza viruses.

Zika and Chikungunya virus co-infection in a traveller returning from Colombia, 2016: virus isolation and genetic analysis

Introduction: Zika virus (ZIKV) and Chikungunya virus (CHIKV) can share the same mosquito vector, and co-infections by these viruses can occur in humans. While infections with these viruses share commonalities, CHIKV is unique in causing arthritis and arthralgias that may persist for a year or more. These infections are commonly diagnosed by RT–PCR-based methods during the acute phase of infection. Even with the high specificity and sensitivity characteristic of PCR, false negatives can occur, highlighting the need for additional diagnostic methods for confirmation. Case presentation: On her return to the USA, a traveller to Colombia, South America developed an illness consistent with Zika, Chikungunya and/or Dengue. RT-PCR of her samples was positive only for ZIKV. However, arthralgias persisted for months, raising concerns about co-infection with CHIKV or Mayaro viruses. Cell cultures inoculated with her original clinical samples demonstrated two types of cytopathic effects, and both ZIKV and CHIKV were identified in the supernatants. On phylogenetic analyses, both viruses were found to be related to strains found in Colombia. Conclusion: These findings highlight the need to consider CHIKV co-infection in patients with prolonged rheumatological symptoms after diagnosis with ZIKV, and the usefulness of cell culture as an amplification step for low-viremia blood and other samples.

Little evidence of human infection with equine influenza during the 2007 epizootic, Queensland, Australia

BACKGROUND Equine influenza virus (EIV) is considered enzootic in Europe (except Iceland), Asia, North Africa, and North and South America. When EIV outbreaks occur they may severely impact the equine and tourist industries. Australia faced its first EIV outbreak beginning in August of 2007. The outbreak was concentrated in New South Wales and Queensland, with more than 1400 confirmed EIV infections in horses during the first month. Rapid response from the equine industry and the federal government was successful and Australia was declared free from EIV by the end of 2007. OBJECTIVES This cross-sectional study was designed to examine associations between exposure to EIV-infected horses and evidence of EIV infection in humans. STUDY DESIGN Employing informed consent, between October 2007 and April 2008, 100 subjects (89 with horse exposures and 11 non-exposed) were enrolled during equine events and at the University of the Sunshine Coast. All subjects provided a blood sample and were asked to complete an online questionnaire including health history, animal exposure and demographic information. Sera samples were tested for the presence of antibodies against two H3N8 EIV strains using microneutralization, hemagglutination inhibition, and enzyme-linked lectin assays. RESULTS Evidence for H3N8 infection was sparse, with only 9 study participants having any indication of H3N8 infection and the seroreactivity seen was low and easily explained by cross-reactions against human influenza strains or vaccines. CONCLUSIONS These data provide little evidence to support the premise that EIV infections occurred among humans exposed to EIV-infected horses during the 2007 Australian epizootic.

Complete Genome Sequences of Identical Zika virus Isolates in a Nursing Mother and Her Infant

ABSTRACT Complete genome sequences were obtained for Zika viruses isolated from the breast milk of a Venezuelan patient and her child, who was exclusively breastfeeding at the time. These sequences are the first to be reported from a presumptive autochthonous postnatal transmission case from mother to child in Venezuela.

Serological evidence of equine influenza infections among persons with horse exposure, Iowa

BACKGROUND Equine influenza virus (EIV) is considered enzootic in North America and experimental studies have documented human EIV infections. STUDY DESIGN This cross-sectional study examined 94 horse-exposed and 34 non-exposed controls for serological evidence of EIV infection. Sera were evaluated for antibodies against three EIV and two human H3N2 viruses using microneutralization (MN), neuraminidase inhibition (NI), enzyme-linked lectin (ELLA), and hemagglutination inhibition (HI) serological assays. Risk factor analyses were conducted using logistic regression and proportional odds modeling. RESULTS There was evidence of previous infection by MN assay against A/equine/Ohio/2003(H3N8) but not the other 2 EIVs. Eleven (11.7%, maximum titer 1:320) horse-exposed and 2 (5.9%, maximum titer 1:160) control subjects had MN titers ≥1:80. Among the horse-exposed, 18 (19.1%) were positive by NI assay and 8 (8.5%) had elevated ELLA titers ≥1:10. Logistic regression modeling among horse-exposed revealed that having an elevated MN or ELLA titer (≤1:10) was associated with having a positive NI titer (OR=4.9; 95% CI=1.3-18.7, and OR=53.2; 95% CI=5.9-478.5, respectively). Upon proportional odds modeling, having worked as an equine veterinarian (OR=14.0; 95% CI=2.6-75.9), having a history of smoking (OR=3.1; 95% CI=1.2-7.7), and receipt of seasonal influenza vaccine between 2000 and 2005 (OR=2.3; 95% CI=1.1-5.0) were important independent risk factors for elevations in MN assay. CONCLUSIONS While we cannot rule out confounding exposures, these data support the premise that occupational exposure to EIV may lead to human infection.

Evidence for Mother-to-Child Transmission of Zika Virus Through Breast Milk

Zikavirus (ZIKV) is an emerging viral pathogen that continues to spread throughout different regions of the world. Herein we report a case that provides further evidence that ZIKV transmission can occur through breastfeeding by providing a detailed clinical, genomic, and virological case-based description.

Evidence for subclinical H5N1 avian influenza infections among Nigerian poultry workers

In recent years Nigeria has experienced sporadic incursions of highly pathogenic H5N1 avian influenza among poultry. In 2008, 316 poultry‐exposed agricultural workers, and 54 age‐group matched non‐poultry exposed adults living in the Enugu or Ebonyi States of Nigeria were enrolled and then contacted monthly for 24 months to identify acute influenza‐like‐illnesses. Annual follow‐up sera and questionnaire data were collected at 12 and 24 months. Participants reporting influenza‐like illness completed additional questionnaires, and provided nasal and pharyngeal swabs and acute and convalescent sera. Swab and sera specimens were studied for evidence of influenza A virus infection. Sera were examined for elevated antibodies against 12 avian influenza viruses by microneutralization and 3 human viruses by hemagglutination inhibition. Four (3.2%) of the 124 acute influenza‐like‐illness investigations yielded molecular evidence of influenza, but virus could not be cultured. Serial serum samples from five poultry‐exposed subjects had a ≥4‐fold change in microneutralization titers against A/CK/Nigeria/07/1132123(H5N1), with three of those having titers ≥1:80 (maximum 1:1,280). Three of the five subjects (60%) reported a preceding influenza‐like illness. Hemagglutination inhibition titers were ≥4‐fold increases against one of the human viruses in 260 participants. While cross‐reactivity from antibodies against other influenza viruses cannot be ruled out as a partial confounder, over the course of the 2‐year follow‐up, at least 3 of 316 (0.9%) poultry‐exposed subjects had evidence for subclinical HPAI H5N1 infections. If these data represent true infections, it seems imperative to increase monitoring for avian influenza among Nigerias poultry and poultry workers. J. Med. Virol. 86:2070–2075, 2014.

Complete Genome Sequences of Chikungunya Viruses Isolated from Plasma Specimens Collected from Haitians in 2014

ABSTRACT Ten chikungunya virus isolates from human plasma collected in Haiti from May to August 2014, in the midst of a chikungunya fever outbreak, were fully sequenced. The resulting genomic sequences are nearly identical, and phylogenetic analyses indicate they belong to the Asian lineage of the virus.