Long ignored but making a comeback: a worldwide epidemiological evolution of human brucellosis

Abstract

Brucellosis is a commonly neglected zoonosis that remains a serious global public health concern. The epidemiological evolution of human brucellosis has considerably changed over the past few decades, and epidemic geography is continuously expanding. Human brucellosis is emerging and re-emerging, and is imported from areas where it is endemic due to travel, immigration, and international trade. The disease continues to be prevalent in Asia and Africa, including West Asia, Central Asia, North Africa, and East Africa, with the highest incidence in Syria, Kyrgyzstan, Mongolia, Iran, Algeria, and Kenya. Re-emerging cases are frequently recorded in places where brucellosis has been controlled, such as Bosnia, Herzegovina, Azerbaijan, and the USA. In countries with a high disease burden, disease control and eradication have been extremely difficult because of livestock farming being the only source of livelihood, unique religious beliefs regarding animals, nomadic lifestyle, and low socioeconomic levels. Interventions focused on protecting livestock keepers are needed, particularly for those assisting with goat and sheep births and the consumption of raw dairy products. Notably, in most countries with a high disease burden, each period of several years with a low incidence rate was followed by a subsequent increase in cases, highlighting the necessity of continuous investment and surveillance. In addition, advocacy for the inclusion of brucellosis as a globally mandated reported disease, strict restrictions on animal movement, mandated consumption of pasteurized milk, and health education are needed. This study will help form an evidence-based strategy for international organizations to curb the future spread of brucellosis.

Keywords: Human brucellosis; cases; epidemiological evolution; incidence rate; seropositive.

Figure 1.

The map of the global brucellosis epidemiological profile (the incidence rates of human brucellosis from public open-source from OIE-WAHIS databases, Table S1). Note: Incidence rate (/100,000) from 2017 to 2019 was used to depict the map of global human brucellosis, the gray indicates areas with no data. The map from Standard Map Services Website (http://bzdt.ch.mnr.gov.cn/), and approval number of map: GS (2016) 1666.

Figure 2.

The map of the brucellosis epidemiological profile in Asian countries in 2018. Note: Incidence rate (/100,000) of human brucellosis from public open-source from OIE-WAHIS databases, the gray indicates areas with no data. The map from Standard Map Services Website (http://bzdt.ch.mnr.gov.cn/), and approval number of map: GS (2016) 1666.

Figure 3.

The incidence rate (/100,000) profile in Asian countries (a–d) with a high disease burden, from 2005 to 2019. Note: the number of cases and the incidence rates of human brucellosis are from public open-source from OIE-WAHIS databases.

Figure 4.

The incidence rate (/100,000) profile in European countries (a and b) with a high disease burden, from 2005 to 2019. Note: the number of cases and the incidence rates of human brucellosis are from public open-source from OIE-WAHIS databases.

Figure 5.

The incidence rate (/100,000) profile in American countries (a (Mexico) and b) with a high disease burden, from 2005 to 2019. Note: the number of cases and the incidence rates of human brucellosis are from public open-source from OIE-WAHIS databases.