Avian influenza: recent epidemiology, travel-related risk, and management

Editorial: mRNA Vaccines and Future Epidemic, Pandemic, and Endemic Zoonotic Virus Infections

There have been rapid developments in safe and effective mRNA vaccines for zoonotic infections in the past year. Years of research have made these advances possible, leading to in vitro-transcribed (IVT) mRNA expressing therapeutic proteins. There are several advantages of mRNA vaccines that include their low-cost manufacturing process, large-scale and rapid production, and the ability to modify the vaccines in response to emerging infections and viral variants. The COVID-19 pandemic and successful vaccination programs for SARS-CoV-2 have highlighted the advantages of mRNA vaccines. Also, mRNA vaccines are in development for several other potential pandemic zoonotic infections, including Ebola virus, rabies virus, Zika virus, HIV-1, and influenza. There may also be hope for the control of pandemic avian influenza by the combination of improved and rapid viral genotyping and the rapid development and mass production of mRNA vaccines. This Editorial aims to present a brief overview of how mRNA vaccines may help control and future epidemic, pandemic, and endemic zoonotic virus infections.

Influenza A viruses in birds and humans: Prevalence, molecular characterization, zoonotic significance and risk factors' assessment in poultry farms

This study aimed to investigate the prevalence of influenza A viruses in birds and humans residing in the same localities of Sharkia Province, Egypt and the risk factors' assessment in poultry farms. A total of 100 birds comprised of 50 chickens, 25 ducks and 25 wild egrets were sampled. Swab samples were collected from 65 people (50 poultry farm workers and 15 hospitalized patients). All samples were screened for the presence of influenza A viruses using isolation and molecular assays. Avian influenza viruses were only detected in chicken samples (18%) and molecularly confirmed as subtype H5. The infection rate was higher in broilers (40%) than layers (8.6%). Influenza A (H1) pdm09 virus was detected in a single human case (1.54%). All the isolated AI H5 viruses were clustered into clade (2.2.1.2) and shared a high similarity rate at nucleotides and amino acid levels. In addition, they had a multi-basic amino acid motif (ـــPQGEKRRKKR/GLFـــ) at the H5 gene cleavage site that exhibited point mutations. Chicken breed, movement of workers from one flock to another, lack of utensils' disinfection and the introduction of new birds to the farm were significant risk factors associated with highly pathogenic AI H5 virus infection in poultry farms (p ≤ 0.05). Other factors showed no significant association. The HPAI H5 viruses are still endemic in Egypt with continuous mutation. Co-circulation of these viruses in birds and pdm09 viruses in humans raises alarm for the emergence of reassortant viruses that are capable of potentiating pandemics.

Development of Multiplex Reverse Transcription-Polymerase Chain Reaction for Simultaneous Detection of Influenza A, B and Adenoviruses

BACKGROUND AND OBJECTIVE

Millions of people in developing countries lose their lives due to acute respiratory infections, such as Influenza A & B and Adeno viruses. Given the importance of rapid identification of the virus, in this study the researchers attempted to design a method that enables detection of influenza A, B, and adenoviruses, quickly and simultaneously. The Multiplex RT PCR method was the preferred method for the detection of influenza A, B, and adenoviruses in clinical specimens because it is rapid, sensitive, specific, and more cost-effective than alternative methods.

METHODS

After collecting samples from patients with respiratory disease, virus genome was extracted, then Monoplex PCR was used on positive samples and Multiplex RT-PCR on clinical specimens. Finally, by comparing the bands of these samples, the type of virus in the clinical samples was determined.

RESULTS

Performing Multiplex RT-PCR on 50 samples of respiratory tract led to following results; flu A: 12.5%, fluB: 50%, adeno: 27.5%, negative: 7.5%, and 2.5% contamination.

CONCLUSION

Reverse transcription-multiplex Polymerase Chain Reaction (PCR) technique, a rapid diagnostic tool, has potential for high-throughput testing. This method has a significant advantage, which provides simultaneous amplification of numerous viruses in a single reaction. This study concentrates on multiplex molecular technologies and their clinical application for the detection and quantification of respiratory pathogens. The improvement in diagnostic testing for viral respiratory pathogens effects patient management, and leads to more cost-effective delivery of care. It limits unnecessary antibiotic use and improves clinical management by use of suitable treatment.

Travellers and influenza: risks and prevention

BACKGROUND

Influenza viruses are among the major causes of serious human respiratory tract infection worldwide. In line with the high disease burden attributable to influenza, these viruses play an important, but often neglected, role in travel medicine. Guidelines and recommendations regarding prevention and management of influenza in travellers are scarce. Of special interest for travel medicine are risk populations and also circumstances that facilitate influenza virus transmission and spread, like travel by airplane or cruise ship and mass gatherings.

METHODS

We conducted a PUBMED/MEDLINE search for a combination of the MeSH terms Influenza virus, travel, mass gathering, large scale events and cruise ship. In addition we gathered guidelines and recommendations from selected countries and regarding influenza prevention and management in travellers. By reviewing these search results in the light of published knowledge in the fields of influenza prevention and management, we present best practice advice for the prevention and management of influenza in travel medicine.

RESULTS

Seasonal influenza is among the most prevalent infectious diseases in travellers. Known host-associated risk factors include extremes of age and being immune-compromised, while the most relevant environmental factors are associated with holiday cruises and mass gatherings.

CONCLUSIONS

Pre-travel advice should address influenza and its prevention for travellers, whenever appropriate on the basis of the epidemiological situation concerned. Preventative measures should be strongly recommended for travellers at high-risk for developing complications. In addition, seasonal influenza vaccination should be considered for any traveller wishing to reduce the risk of incapacitation, particularly cruise ship crew and passengers, as well as those participating in mass gatherings. Besides advice concerning preventive measures and vaccination, advice on the use of antivirals may be considered for some travellers.

The Intranasal Application of Zanamivir and Carrageenan Is Synergistically Active against Influenza A Virus in the Murine Model

BACKGROUND

Carrageenan is a clinically proven and marketed compound for the treatment of viral upper respiratory tract infections. As infections caused by influenza virus are often accompanied by infections with other respiratory viruses the combination of a specific anti-influenza compound with the broadly active antiviral polymer has huge potential for the treatment of respiratory infections. Thus, the combination of the specific anti-influenza drug Zanamivir together with carrageenan in a formulation suitable for intranasal application was evaluated in-vitro and in-vivo.

PRINCIPAL FINDINGS

We show in-vitro that carrageenan and Zanamivir act synergistically against several influenza A virus strains (H1N1(09)pdm, H3N2, H5N1, H7N7). Moreover, we demonstrate in a lethal influenza model with a low pathogenic H7N7 virus (HA closely related to the avian influenza A(H7N9) virus) and a H1N1(09)pdm influenza virus in C57BL/6 mice that the combined use of both compounds significantly increases survival of infected animals in comparison with both mono-therapies or placebo. Remarkably, this benefit is maintained even when the treatment starts up to 72 hours post infection.

CONCLUSION

A nasal spray containing carrageenan and Zanamivir should therefore be tested for prevention and treatment of uncomplicated influenza in clinical trials.

Middle East respiratory syndrome coronavirus "MERS-CoV": current knowledge gaps

The Middle East respiratory syndrome coronavirus (MERS-CoV) that causes a severe lower respiratory tract infection in humans is now considered a pandemic threat to the Gulf region. Since its discovery in 2012, MERS-CoV has reached 23 countries affecting about 1100 people, including a dozen children, and claiming over 400 lives. Compared to SARS (severe acute respiratory syndrome), MERS-CoV appears to kill more people (40% versus 10%), more quickly, and is especially more severe in those with pre-existing medical conditions. Most MERS-CoV cases (>85%) reported thus far have a history of residence in, or travel to the Middle East. The current epidemiology is characterised by slow and sustained transmission with occasional sparks. The dromedary camel is the intermediate host of MERS-CoV, but the transmission cycle is not fully understood. In this current review, we have briefly summarised the latest information on the epidemiology, clinical features, diagnosis, treatment and prevention of MERS-CoV especially highlighting the knowledge gaps in its transmission dynamics, diagnosis and preventive strategy.