Duck “beak atrophy and dwarfism syndrome” disease complex: Interplay of novel goose parvovirus‐related virus and duck circovirus?

As a newly emerged infectious disease, duck “beak atrophy and dwarfism syndrome (BADS )” disease has caused huge economic losses to waterfowl industry in China since 2015. Novel goose parvovirus‐related virus (NGPV ) is believed the main pathogen of BADS disease; however, BADS is rarely reproduced by infecting ducks with NGPV alone. As avian circovirus infection causes clinical symptoms similar to BADS , duck circovirus (DuCV ) is suspected the minor pathogen of BADS disease. In this study, an investigation was carried out to determine the coinfection of NGPV and DuCV in duck embryos and in ducks with BADS disease. According to our study, the coinfection of emerging NGPV and DuCV was prevalent in East China (Shandong, Jiangsu and Anhui province) and could be vertical transmitted, indicating their cooperative roles in duck BADS disease.     

Advances in treating drug-resistant hepatitis B virus in HIV-infected patients

Introduction: Treatment of HIV infection with nucleos(t)ide analogs active against hepatitis B virus (HBV) highly improves hepatic outcomes in HIV-HBV coinfected patients, especially when tenofovir (TDF) is part of the antiviral regimen. Drug resistance has been the major drawback and must remain as the most important caveat when planning to treat dually or HIV and HBV independently in coinfected patients.

Areas covered: The use of lamivudine (LAM) as the only active anti-HBV agent should strongly be discouraged in HIV-HBV coinfected patients, although it might be considered for individuals with low serum HBV-DNA and in the absence of liver cirrhosis as an exception. In any other case drug resistance may cause any clinical benefit of this antiviral HBV therapy to disappear, and lead to cross-resistance with other antivirals and even occasionally select for HBV vaccine escape mutants. In cirrhotics, liver enzyme flares may be accompanied by life-threatening decompensation. Entecavir is generally not recommended as an anti-HBV agent in HIV-HBV coinfected patients given its low residual antiretroviral activity and potential for selection of resistance mutations in HIV. Adefovir is not active against HIV using HBV dosing and is no longer recommended as HBV therapy given its limited antiviral effect. Finally, telbivudine is not active against HIV, it is less potent than TDF against HBV and depicts low barrier to resistance and cross-resistance to LAM or emtricitabine.

Expert Opinion: The introduction of TDF has drastically reduced the clinical relevance of hepatitis B drug resistance in HIV-HBV coinfected individuals. The use of LAM as the only active anti-HBV agent should strongly be discouraged in this population.     

Cholera‐schistosomiasis coinfection dynamics

The present work investigates the coinfection dynamics of the cholera and schistosomiasis diseases. The steady states of the model are examined. We obtain results for the model in detail and present the stability results whenever the basic reproduction number is less than unity ( ). For each submodel, the existence of backward bifurcation is presented and for the coinfection model. Furthermore, we formulate an optimal control problem with an appropriate set of control variables. The optimal control problem and the associated results are derived and discussed. The optimal control problem and the suggested controls are utilized to obtain optimal control characterizations. Numerical results are presented by choosing various optimal control strategies for the early elimination of both infections from the population. It is suggested that appropriate uses and application to the population could significantly reduce the infection. Therefore, based on our findings, we suggest to the public health department that the only possible cost‐effective strategy for the elimination of schistosomiasis and cholera coinfection is the combination of both diseases' preventive measures and the treatment of schistosomiasis.     

HIV-1/hepatitis B coinfection

Reviews the epidemiology, natural history and the current status of treatment of HIV/hepatitis B coinfection.     

Guidelines on the Treatment of Chronic Coinfection by Trypanosoma cruzi and HIV Outside Endemic Areas

Abstract

As a result of population migration, Chagas disease is no longer limited to the North and South American continents. In HIV-infected patients, chronic infection by Try-panosoma cruzi behaves as an opportunistic infection in severely immunosuppressed patients and is responsible for high morbidity and mortality. Unlike other opportunistic infections, information on the natural history, diagnosis, treatment, and prevention of Chagas disease is scarce. Spain has the highest number of cases of Chagas disease outside the North and South American continents, and coinfection with HIV is increasingly prevalent. In this article, the Spanish Society for Tropical Medicine and International Health (Sociedad Española de Medicina Tropical y Salud Interna-cional) reviews the current situation of coinfection with HIV and T. cruzi infection and provides guidelines on the diagnosis, treatment, and prevention in areas where Cha-gas disease is not endemic. It also identifies areas of uncertainty where additional research is necessary.     

Prevalence of hepatitis B and hepatitis D coinfection in asymptomatic blood donors in Iran

Hepatitis delta virus (HDV) is a satellite virus that needs hepatitis B virus (HBV) surface antigen for amplification and transition. HDV appears in HBsAg carriers as acute coinfection and superinfection in patients with chronic hepatitis B. This coinfection leads to chronic hepatitis, cirrhosis, and liver carcinoma. The aim of this study was to detect the prevalence of coinfection and superinfection of HBVs and HDVs in blood donor individuals in Iran. Sera from 854 asymptomatic blood donors from the Bank of positive samples storage at the National Blood Transfusion Organization of Iran that were positive for hepatitis B surface antigen were analysed. The presence of antibody against HDV in blood donors was detected using ELISA followed by conventional PCR, seminested PCR and real‐time PCR to determine coinfection and/or superinfection. Restriction fragment length polymorphism was used for HDV genotyping. All 854 samples were HBsAg and anti‐HBc positive whereas only 18 (2%) of them were positive for anti‐HDV. Of the 854 samples, 154 (18%) were HBV‐DNA positive. HDV‐RNA was detected in 0.6% of the total samples by seminested PCR and real‐time PCR and the two PCR methods produced similar results. Moreover, 16.6% and 83.4% of anti‐HDV‐positive samples exhibited coinfection and superinfection with HBV, respectively. Genotype I of HDV was determined in positive samples.     

Tratamiento de la hepatitis C en grupos de pacientes especiales

The treatment plan for chronic hepatitis C in special populations varies according to comorbidity and the current evidence on treatment. In patients with hepatitis C virus and HIV coinfection, the results of dual therapy (pegylated interferon plus ribavirin) are poor. In patients with genotype 1 infection, triple therapy (dual therapy plus boceprevir or telaprevir) has doubled the response rate, but protease inhibitors can interact with some antiretroviral drugs and provoke more adverse effects.These disadvantages are avoided by the new, second-generation, direct-acting antiviral agents. In patients who are candidates for liver transplantation or are already liver transplant recipients, the optimal therapeutic option at present is to combine the new antiviral agents, with or without ribavirin and without interferon. The treatment of patients under hemodialysis due to chronic renal disease continues to be dual therapy (often with reduced doses of pegylated interferon and ribavirin), since there is still insufficient information on triple therapy and the new antiviral agents. In mixed cryoglobulinemia, despite the scarcity of experience, triple therapy seems to be superior to dual therapy and may be used as rescue therapy in non-responders to dual therapy. However, a decision must always be made on whether antiviral treatment should be used concomitantly or after immunosuppressive therapy.