Epidemiological characteristics and financial losses due to avian aspergillosis in households in the Almaty region, Republic of Kazakhstan

Abstract

Aspergillosis is a severe fungal disease that affects all species and ages of poultry and leads to significant economic losses within the poultry industry. The economic significance of aspergillosis is associated with direct losses due to poultry mortality, a decline in the production of meat and eggs, feed conversion, and poor growth of recovering poultry. Although a decrease in the production of poultry meat and eggs in Kazakhstan due to this fungal disease has been widely reported, studies on the consequent financial losses on affected farms (households) have not been carried out. This study aimed to estimate the financial losses and epidemiological parameters of avian aspergillosis among households affected by the disease in the Almaty region. To achieve the objectives of the research, a survey was conducted involving affected households from February 2018 to July 2019. The affected poultry were diagnosed based on clinical, macroscopical, and microscopical procedures, and once the infection was confirmed, household owners were interviewed. Data were collected from 183 household owners. The median incidence risk and fatality rates were 39 and 26% in chickens, 42 and 22% in turkeys, and 37 and 33% in geese, respectively, with young poultry having a higher incidence risk and fatality rate than adults. Approximately 92.4% of the household owners treated the affected poultry using natural folk methods and 7.6% of household owners used antifungal drugs and antibiotics, spending a median of US $35.20 (min US $0; max US $400) per household throughout the course of the infection. Egg production was reduced by a median of 58.3% when households were affected. The price of poultry fell by a median of 48.6% immediately after recovery due to weight loss. The median of the overall financial losses of households was US $198.50 (min US $11; max US $1,269). The majority of household owners (65%) did not replace their poultry, 9.8% of household owners replaced all their poultry, and the remaining 25.1% replaced only a proportion of the poultry lost at the time of the study. Newly acquired poultry were purchased from neighbors (10.9%), fellow villagers (50%), and state poultry farms (39.1%). This study demonstrates that aspergillosis has an immediate impact on subsistence household owners' livelihoods in the Almaty region of Kazakhstan.

Investigation of aspergillosis outbreak in young ducklings: Unraveling the role of hatcheries in Aspergillus fumigatus transmission

“…is found in unhatched eggs and hatchery trash [44] . Usually, death of the infected embryos occurs between the 15th and 18th incubation days, which may lead to decreased hatchability of up to 30% [2 , 4 , 44 ]. Potential embryo infection occurs in dust containing more than eight hundred colonies per gram.…”

“…It is caused by an infection with Aspergillus species and the vulnerability of the avian lung-air sac system to airborne pollutants and particulate matter [1] . Aspergillus fumigatus ( A. fumigatus ) is the most pathogenic fungus affecting poultry [2] , and Aspergillus niger (A. niger) can also affect poultry adversely [3 , 4 ] . Infections could occur when birds are exposed to a massive number of spores, food contamination, inadequate ventilation, and bad sanitation, all of which contribute to fungal development [1] .…”

“…Both A. fumigatus and A. niger were isolated from dead-in-shell eggs with prevalences of 28.0% and 18.6%, respectively, out of a 66.9% rate from 79 fungal isolates [6] . Exposure to environmental sources, including in ovo, is also implicated in infection [4] . Mortality rates during spontaneous epidemics varied between 4.5% and 90%, contingent upon the age and immune status of the avian species impacted [2] .…”