Research Article: Brucellosis and Coxiella burnetii Infection in Householders and Their Animals in Secure Villages in Herat Province, Afghanistan: A Cross-Sectional Study

Date Published: October 20, 2015

Publisher: Public Library of Science

Author(s): Zarif Akbarian, Ghulam Ziay, Willy Schauwers, Bashir Noormal, Islam Saeed, Abul Hussain Qanee, Zabiullah Shahab, Tania Dennison, Ian Dohoo, Ronald Jackson, John A. Crump.

Abstract: BackgroundBrucellosis and coxiellosis are known to be endemic in ruminant populations throughout Afghanistan, but information about their prevalence and factors that affect prevalence in householders and livestock under diverse husbandry systems and pastoral settings is sparse.Methods/Principal FindingsWe conducted a cross-sectional survey to investigate the seroprevalence of brucellosis and Coxiella burnetii in humans and livestock in six secure districts in Herat from 26th December 2012–17th January 2013. A total of 204 households with livestock were surveyed in six Kuchi and five sedentary type villages. Blood samples from 1,017 humans, 1,143 sheep, 876 goats and 344 cattle were tested for brucellosis and Q fever. About one in six households (15.7%) had at least one Brucella seropositive person, about one in eight households (12.3%) had at least one Brucella seropositive animal and about one in four (24.5%) had either seropositive animals or humans. Ninety-seven percent of households had at least one C. burnetii seropositive person and 98.5% of households had one or more C. burnetii seropositive animals. Forty- seven householders had serological evidence of exposure to both C. burnetii and Brucella and eight animals were serologically positive for both diseases. Drinking unpasteurised milk (OR 1.6), treating animals for ticks (OR 1.4), milking sheep (OR 1.4), male gender (OR 1.4) and seropositivity to Brucella (OR 4.3) were identified as risk factors for seropositivity to C. burnetii in householders. Household factors associated with households having either Brucella seropositive animals or humans were Kuchi households (OR 2.5), having ≤4 rooms in the house (OR 2.9) and not owning land (OR 2.9).ConclusionsThe results from this study provide baseline information for the planning and monitoring of future interventions against these diseases. The implementation of this study greatly improved collaboration, coordination and capability of veterinary and public health professionals from government, NGOs and donor funded projects.

Partial Text: Brucellosis and coxiellosis are known to be endemic in ruminant populations throughout Afghanistan but information about their prevalence and factors that affect prevalence in householders and livestock under diverse husbandry systems and pastoral settings is sparse. Brucellosis in animals results in economic losses due to decreased productivity from abortions and reduced milk yield while the disease in humans can be severely debilitating, often with long- term adverse consequences for health [1]. C. burnetii causes abortions in domestic ruminants and fever, pneumonia, meningo-encephalitis and hepatitis in acute cases of Q fever in humans and endocarditis in chronic cases [2,3]. Little is known about the epidemiology of C. burnetii in animals and humans in Afghanistan although a United Nations Food and Agriculture (FAO) funded study found serological evidence of its occurrence in Bamyan province in 2011 [4]. Brucellosis and Q fever are likely to be severely under-diagnosed and reported as they are not specifically included in the list of diseases in the donor-funded Essential Package of Hospital Services and Basic Package of Health Services. Until the start of this study there were no facilities for testing for C. burnetii at the central veterinary and public health laboratories in Kabul or elsewhere in the Republic. It is highly likely that both B. melitensis and B. abortus are present in Afghanistan but there is currently no in-country diagnostic capability for their culture or differentiation.

A cross-sectional survey to investigate the seroprevalence of seropositivity to brucellosis and C. burnetii in humans and livestock (cattle, sheep and goats) was conducted in six secure districts in Herat from 26th December 2012–17th January 2013. Secure villages were located in districts considered to be secure because of no overt signs of anti-government activities therein, thus enabling public health and veterinary government agencies and DCA teams to conduct routine activities safely. The population of interest was humans and female livestock (cattle, sheep and goats) of breeding age in households in selected villages in Herat Province. The principal epidemiologic unit of interest was households with consideration given to both animals and humans within each household. A total of 204 households were surveyed in 11 villages, six of which were Kuchi [5] and five were sedentary type. Sedentary villages were selected from a list provided by the Afghanistan Information Management System which listed all the villages in Afghanistan in 2006. Kuchi are nomadic or transhumant pastoralists. Their villages were selected from a list provided by the Dutch Committee for Afghanistan (DCA) and the veterinary field units supported by the DCA identified their locations as at October 2012. Up to date data on numbers of livestock in households were not available. The last livestock census, which was sample based, was conducted by FAO in 2002–2003. Villages were randomly selected using the Data Analysis Tool in Microsoft Excel 2007 and 20 plus five reserve households in each village were randomly selected from a list provided by village elders of all households with livestock. In each household blood samples were collected in sterile red top or serum separation vacutainers from up to five householders ≥9 and ≤60 years of age and up to 10 randomly selected female sheep and goats of breeding age and up to five female cattle of breeding age. The sample size of five householders was based on the average Afghan household size of 7.6 persons. Individual human data recorded at the time of sampling included age, sex, marital status, occupation and history of abortions (if married) and for animals were species, age and abortion history (see S1 File and S2 File in Supplementary Information). “Small ruminants” is used throughout the paper as the collective term for sheep and goats.

Despite its conceptual appeal [6] and successful application over the past 20 years for infectious diseases such as bovine spongiform encephalopathy, highly pathogenic H5N1 avian influenza, C. burnetii and leptospirosis, linked public health and veterinary field investigations of important zoonoses for which the reservoir hosts are farmed ruminants have been rarely conducted in low income countries. Serological studies involving humans and their livestock have been reported for brucellosis in Kyrgyzstan [7], Mongolia [8] and Egypt [9], for C. burnetii in Egypt [10] and for both brucellosis and Q fever in Chad [11] and the authors are aware of several unpublished investigations for brucellosis in Central Asia and China. Our study was made possible by the terms of reference for the series of in-country studies in South Asia conducted under the Massey University European Commission funded and World Bank administered South Asia project which embodied veterinary and public health collaboration and allowed for investigator’s judgement for collection of information about the three zoonoses of interest which are characterised by multiple allied risk factors for transmission. Our inclusion of brucellosis and Q fever as the diseases of interest approach has obvious marginal cost advantages over study designs which are confined to one disease of interest.



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