Prevalence of Helicobacter pylori Infection in Warao Lineage Communities of Delta Amacuro State, Venezuela

Vol. 98(6): 721-725, September 2003

Diana Ortiz/⁺, María Eugenia Cavazza, Orquídea Rodríguez, Isabel Hagel, MaríaCorrenti*, Jacinto Convit

Instituto de Biomedicina, Ministerio de Salud y Desarrollo Social, Universidad Central de Venezuela, Apartado Postal 4043, Caracas 1010A, Venezuela *Instituto de Oncología y Hematología, Ministerio de Salud y Desarrollo Social, Caracas, Venezuela

The purpose of this study was the evaluation of Helicobacter pylori infections in children and adults from two indigenous communities of Delta Amacuro State, Venezuela, that differ in hygienic conditions of the housing. The evaluation was performed in 98 children (mean age 7 ± 3.37 years) and their mothers (33.96 ± 13.77 years) from two communities of Warao lineage. Anti-H. pylori serum IgG and secretory anti-H. pylori IgA antibodies were de-termined, as well as total secretory IgA and H. pylori antigens in feces. Serological prevalence of H. pylori infection was 38% in children and 84% their in mothers. Children from the community that had the most deficient sanitary and hygienic conditions had significantly lower titers of specific IgG antibodies and total secretory IgA (P < 0.0001) and a high percentage of them had H. pylori antigens in their feces (P < 0.0001). The levels of specific IgA were similar in both groups. The results indicate that in these populations there is a high prevalence of H. pylori infection and that poor hygienic conditions can increase the risk of infection and damage to the gastrointestinal tract.

Key words: Helicobacter pylori - secretory IgA - seroprevalence - Venezuela

Helicobacter pylori colonizes about 50% of the world population; less than 20% of affected individuals develop gastroduodenal diseases. Gastroduodenal diseases associated with H. pylori occur mainly in adults. Nevertheless, the infection is usually acquired during childhood (Wotherspoon et al. 1993) and it is possible that the humoral and mucosal tissue responses at that time can determine the natural course of the infection (Torres et al. 2000).

Although studies suggest that the majority of individuals acquire H. pylori in childhood, the mi-crooganism can persist in its gastric habitat for decades. It is acquired from another family member (Brenner et al.1999, Rothenbacher et al.1999). During this time, it can undergo considerable genetic changes that could facilitate adaptation to the gastric ecosystem of a particular host, including changes in environmental features brought about by H. pylori colonization (Falk et al. 2000). H. pylori isolates from un related individuals have totally different genetic fingerprints, so that H. pylori can be considered a "quasi-species" (Covacci et al. 1997).

It has been reported at a worldwide level that H. pylori infection prevalence in children varies between 10% and 80% (Vaira et al. 1994, Torres et al. 2000). The lowest prevalence has been found in populations in Northern and Eastern Europe, Japan and other parts of Asia. High prevalence has been well documented in India and Bangladesh and in certain cities of Africa and Latin America (Torres et al. 2000).

In a study where prevalence by ethnic category was examined, an increase in immigrant groups from high prevalence regions was reported, as well as in low socio-economic level ethnic risk groups (Ma et al. 1998, Vorobjova et al. 2000). Again increase with age, low socio-economic and educational levels, race, crowded living quarters, migration from high prevalence regions, background of H. pylori-infected family members, poor nutritional state indicators, ingestion of water and vegetables which do not fulfill hygienic conditions, have been reported as risk factors for the increase of H. pylori infection (Graham et al. 1991, Smoat et al. 1994, Torres et al. 2000).

Few studies have examined the incidence of H. pylori infection in children, possibly due to the ethical considerations involved in carrying out invasive tests which are not really required in these age groups. On the other hand, studies in indigenous communities are troublesome to carry out because of the difficulties of both physical and cultural accessibility. The main purpose of this study was the evaluation of H. pylori infection in children and adults from two indigenous communities of Delta Amacuro State in Venezuela.

MATERIALS AND METHODS

RESULTS

DISCUSSION

ACKNOWLEDGEMENTS

To Dr Marian Ulrich and Dr Mario Sanchez Borges for reviewing the manuscript. To the local authorities of Delta Amacuro State. Mrs Niria Zabaleta and Lourdes Becerra collaborated in the evaluation of the children. To Warao indigenous populations for allowing us to enter and participate in their communities.

REFERENCES

Fig. 1 | Fig. 2 | Table I | Table II

This investigation was financed by Conicit Project S1-96001408, and by the Program for Special Attention to Indigenous Populations, coordinated by General Victor Salom the National Guard of Venezuela.

⁺Corresponding author. Fax: +58-212-861.8670. E-mail: dprincz@hotmail.com

Received 5 July 2002

Accepted 14 July 2003