Population Prevalence of Trachoma in Nine Rural Non-Indigenous Evaluation Units of Brazil

ABSTRACT

Purpose

To assess the contemporary prevalence of trachoma in Brazil’s non-indigenous population, surveys of those thought to be at greatest risk of disease were conducted.

Methods

Rural census tracts of non-indigenous population from nine mesoregions were selected to compose the survey evaluation units (EUs) by considering previously endemic municipalities at greatest risk of trachoma. In each of the nine EUs, we conducted a population-based prevalence survey. Every resident of selected households aged $\ge$1 year was examined for trachomatous inflammation — follicular (TF) and trachomatous trichiasis (TT). Additionally, data were collected on household-level access to water, sanitation, hygiene (WASH) and education.

Results

A total of 27,962 individuals were examined across nine EUs. The age-adjusted TF prevalence in 1–9-year-olds was <5% in each EU. The age- and gender-adjusted prevalence of TT unknown to the health system in ≥15-year-olds was <0.2% in eight EUs; in one EU, it was 0.22%. The median number of households surveyed per EU with access to an improved drinking water source within a 30-minute roundtrip of the house was 66%. School attendance was >99% of surveyed children.

Conclusions

The prevalence of TF was well below the target for elimination as a public health problem in all EUs. Because EUs surveyed were selected to represent the highest-risk non-indigenous areas of the country, TF prevalence is unlikely to be ≥5% in non-indigenous populations elsewhere. In one EU, the prevalence of TT was above the target threshold for elimination. Further investigation and possibly improvement in TT surgical provision are required in that EU.

KEYWORDS:

• Trachoma
• trichiasis
• Brazil
• prevalence
• neglected tropical diseases
• elimination
• WASH
• Tropical Data

Supplemental data

Supplemental data for this article can be accessed on the publisher’s website.

Declaration of interest

SB, AB and RW were employed by the International Trachoma Initiative at The Task Force for Global Health, which receives an operating budget and research funds from Pfizer Inc., the manufacturers of Zithromax® (azithromycin); Pfizer donates Zithromax through the International Trachoma Initiative for trachoma elimination purposes where needed. EHE receives salary support from the International Trachoma Initiative. The other authors report no conflicts of interest. MISD is staff member of the Pan American Health Organization (PAHO). AWS is a staff member of the World Health Organization. The authors alone are responsible for the views expressed in this article and they do not necessarily represent the views, decisions or policies of the institutions with which they are affiliated. In any reproduction of this article, there should be no suggestion that PAHO, WHO or this article endorse any specific organization, products or services. The use of PAHO or WHO logos is not permitted. This notice should be preserved along with the article´s original URL.

Disclaimer

The authors alone are responsible for the views expressed in this article and they do not necessarily represent the views, decisions or policies of the institutions with which they are affiliated, USAID or the United States Government.

Additional information

Funding

The surveys were financed by the Brazilian Ministry of Health. Robert Butcher's salary was funded by the Fred Hollows Foundations. Core Tropical Data funding was provided by the International Trachoma Initiative; Sightsavers; and RTI International through the United States Agency for International Development (USAID) Act to End NTDs | East program. The contents do not necessarily reflect the views of USAID or the United States Government. The authors alone are responsible for the views expressed in this article and they do not necessarily represent the views, decisions or policies of the institutions with which they are affiliated. Other than the technical contributions of named authors, none of the funders had any role in project design, in project implementation or analysis or interpretation of data, in the decisions on where, how or when to publish in the peer-reviewed press, or in preparation of the manuscript.