Avian infectious bronchitis virus in Africa: a review

Abstract

Infectious bronchitis virus (IBV) is worldwide in distribution, highly infectious, and extremely difficult to control because it has extensive genetic diversity, a short generation time, and a high mutation rate. IBV is a Gammacoronavirus, single-stranded, and positive-sense RNA virus. Avian infectious bronchitis is well studied in European countries with identification of a large number of IBV variants, whereas in African countries epidemiological and scientific data are poor and not updated. However, previous studies reported that an IBV variant continues to appear regularly in Africa, as currently described in Morocco. No cross-protection between IBV strains was reported, some being unique to a particular country, others having a more general distribution. This review aims to provide a general overview on IB disease distribution in African countries and an update on the available studies of IBV variants in each country.

Detection of infectious bronchitis virus 793B, avian metapneumovirus, Mycoplasma gallisepticum and Mycoplasma synoviae in poultry in Ethiopia

“…A recent review of IBV in Africa (Khataby et al 2016) contained no papers from East Africa, although numerous strain variants, including some unique to particular countries, have been reported in North and West Africa and southern parts of the continent. Reports from other countries worldwide, such as Bangladesh, Mexico, Oman and Algeria, where the poultry sectors are transforming, all indicate that these respiratory pathogens are a common and widespread source of concern to the developing industries (Islam et al 2014; Rivera-Benitez et al 2014; Al-Shekaili et al 2015b; Sid et al 2015).…”

Current situation, genetic relationship and control measures of infectious bronchitis virus variants circulating in African regions

“…This disease is controlled mainly by vaccination in most African countries, using live attenuated or inactivated vaccines frequently based on Massachusetts strain (Khataby et al, 2016) However, outbreaks of IB are still occurring in vaccinated flocks, indicating that, most probably, emergence of new variants from different serotypes to the vaccine strain used. It is sometimes necessary to develop specific vaccines to control the disease, when the commercial vaccines fail to give an adequate protection against the emerging variants virus.…”

“…IB has a large geographical distribution and it was found in regions of America, Europe, Asia, Australia and Africa (Liu et al, 2003;Lee et al, 2010). In Africa, IBV is one of the main and the most important viral respiratory diseases of chickens; it is considered an epidemic virus and widely spread both in vaccinated and unvaccinated poultry farms (Ahmed, 1954;Jackwood, 2012;Khataby et al, 2016). It was described and recognized for the first time in North Africa, especially in Egypt since 1950s (Eissa et al, 1963), from birds showing respiratory signs and confirmed by Eissa et al (1963), in Morocco in 1983(El Houadfi and Jones, 1985, in Tunisia between 2009 and 2013 (Bourogaˆa et al, 2009), in Libya in 2012(Awad et al, 2014, and in Algeria (Sid et al, 2015).…”

Origin and evolution of LX4 genotype infectious bronchitis coronavirus in China

“…Since IBV was first described in 1936, many IBV genotypes/serotypes and variants have been identified (Jackwood, 2012). It is believed that only a small proportion of these have become widespread and predominant in countries with significant poultry industries, it is believed that the majority of these strains have either disappeared or become endemic in certain geographical areas (Khataby et al, 2016). In the last few years, one of the most predominant IBV genotypes circulating in the chicken flocks worldwide is thought to be the LX4 strain (also known as QX-like) de Wit et al, 2011;Jackwood, 2012).…”