**2. Epidemiology**

Trachoma is endemic in 44 countries, and the highest prevalence are in sub-Saharan Africa, Asia, Latin America, and the Middle East [4, 6, 10]. *C. trachomatis* infection occurs mostly in children, and in areas where trachoma is endemic, the first infection usually occurs in the first 2 years of life. Even though initial infections may resolve spontaneously, they are frequently followed by reinfection or superimposed bacterial conjunctivitis [11]. However, the prevalence generally declines to low levels in adults [12].

Complications arising from trachoma may result in severe ocular pains and loss of vision with its attendant poor quality of life and loss of economic productivity [13]. In 2021, approximately 1.9 million people were blind or suffer significant visual impairment from trachoma with over 136 million people living in communities requiring trachoma elimination programs [14].

## **2.1 Morbidity and mortality**

Approximately, 1.9 million people are blind because of trachoma [8]. The risk of mortality in endemic communities is increased among those blinded by the disease [14].

## **2.2 Poverty**

Trachoma is a disease of the poor and deprived [4, 15]. The risk of active trachoma is higher in households with crowed living spaces and poor sanitation. Trachoma persists in low- and middle-income countries (LMICs) where resources are scarce and shared within households [16]. Additionally, the disability that results from the sequelae of chronic infection with C. trachomatis such trichiasis and corneal opacities may lead to reduced productivity and unemployment. Demonstrably, trachoma remains a good proxy of inequality in a population [16, 17]. A study in Ethiopia found that within communities afflicted with trachoma, individuals and households affected by trachomatous trichiasis (TT) are significantly poorer economically than those that are not affected [18]. Trachoma therefore creates a vicious cycle of poverty that traps those affected.

## **2.3 Race and sex**

Trachoma remains a disease of poverty and poor hygiene. Consequently, trachoma has no racial predilection [19]. The disease affects the marginalized and deprived members of the communities [20]. The disease persists in communities with inadequate access to water and sanitation and in dry, dusty, and hot climates [15, 21, 22]. Other agents of transmission include dirty faces, eye-seeking flies (particularly, *Musca sorbens*), and fomites such as clothing.

Women are usually affected by severe trachoma more than twofold compared to men [19, 23]. Because women carry the burden of childcare in most endemic communities, they tend to be more at risk. School age children harbor the active forms of the disease, thereby increasing exposure to C trachomatis [19].
