PREVALENCE OF HEPATITIS A VIRUS AMONG
ARABIAN CHILDREN: A COMMUNITY-BASED STUDY
Rashed S. Al
endemic in Saudi Arabia, with about 90% of the adult population
having positive anti-HAV. A population-based survey of hepatitis
B virus markers provided an opportunity to determine the
age-related prevalence of anti-HAV among Saudi children and
examine some of the factors that influence its transmission in
the community. The overall prevalence of anti-HAV is 52.4% of
4375 children tested. There was no significant difference in HAV
prevalence between males and females (51.3% vs 53.5%). The
age-specific rates, which were similar in both sexes, indicated
the lowest rate in infants with a steady increase in the older
age group. There was a marked regional variation in anti-HAV
prevalence, the Eastern region showing the lowest prevalence
(38.4%), while the Northwestern region showed the highest
prevalence (67%). In nearly all the regions, rural inhabitants
had a higher prevalence than urban residents. Socioeconomic
factors had a significant correlation with the prevalence of
anti-HAV, with the level of education of parents having the
strongest influence on HAV prevalence. The high overall HAV
prevalence in children confirms that Saudi Arabia is endemic for
HAV infection, despite the recent improvement in the
socioeconomic standards of its population. The pattern of HAV
may be changing in Saudi Arabia as the prevalence has dropped in
the Central province compared to previous reports. The need for
the introduction of hepatitis A vaccination will be determined
in the future definition of HAV epidemiology in Saudi Arabia.
Ann Saudi Med 1997;17(2):200-03.
A virus (HAV) has a worldwide distribution. The prevalence
varies from one population to another and is related to
socioeconomic factors and living standards of the population.1,2
In the developing countries, HAV is acquired very early in life
and nearly 100% of adults have detectable levels of antibody to
HAV (anti-HAV). In such countries, epidemics of HAV are
uncommon.2,3 In contrast, the epidemiology of HAV in
the developed countries is characterized by a low prevalence
among children and a large susceptible pool of adults being
negative for anti-HAV. This pattern is associated with high
standard of hygiene and sanitation.4,5 In countries
which dramatically improved their socioeconomic status and
standards of living, the susceptible pool may increase rapidly
to such an extent that HAV becomes a major public health
problem.6 Earlier surveys in Saudi Arabia indicated
that HAV is endemic in Saudi Arabia, with approximately 90% of
the adult population having positive anti-HAV.7-10
last 10 years, a major socioeconomic development has taken place
in Saudi Arabia. There has been dramatic improvement in the
levels of personal and
Department of Medicine, College of Medicine and KKUH, King Saud
University, Riyadh, Saudi Arabia.
reprint requests and correspondence to Dr. Rashed S. Al Rashed,
Division of Gastroenterology (59), P.O. Box 2925, Riyadh 11461,
for publication 28 September 1996. Received 14 April 1996.
hygiene and in the proportions of the Saudi population, and the
impact of these changes on the prevalence of HAV infection has
yet to be determined.
population-based survey of hepatitis B virus markers, undertaken
in 1989 as a baseline for a mass hepatitis B vaccination
program,11 provided an opportunity to determine the
age-related prevalence of anti-HAV among Saudi children and to
examine some of the factors that may influence its transmission
in this community.
about 2.2 million square kilometers, and located in the Arabian
Peninsula, Saudi Arabia had an estimated population of 10
million people in 1981,12 almost equally equally
distributed in the urban and rural areas. The significant
improvement in the socioeconomic status within the last two
decades is demonstrated by a well-developed road network,
communication, water supply, distribution of electricity, as
well as a comprehensive health care delivery system in the
country, which has lessened the differences between the rural
(village or town of less than 30,000 people) and urban
populations. In some villages, the water supply is obtained from
deep wells within compounds or from distribution by water
tankers. There is no difference between rural and urban
population with regard to ethnicity or to cultural and religious
practices. In many of the areas,
to 30% of the population are Bedouins, who have a nomadic
lifestyle and live mostly in tents, and are not registered.11
health care delivery system divides the country into 14
administrative regions, each of which comprises a group of
primary health care centers (PHCC). The catchment area for each
PHCC is a cluster of households located within well-defined
boundaries. Each household has a registration file in the PHCC,
in which all demographic and health records of family members
are kept. The projected total number of households was estimated
as 1,816,373, with an average family size of seven.11
national census estimates that about 25% of the population (2.5
million children) are aged 1 to 10 years and that proportions of
males and females are approximately equal. Assuming that the
prevalence of HBsAg might be about 10%-20% in Saudi children and
a standard error of 0.005, the sample size required was
calculated to be 3600. To accommodate the proportion of tent
dwellers (Bedouins), 20% was added, giving a projected total of
4320. It was decided to survey 10% of the estimated total
households (1816), recruiting not more than two children from
each household. The sampling method used for this has been
described in detail previously.11
each area, clusters defined by the boundaries of the catchment
of the respective PHCC and households within these clusters were
randomly selected and visited by well-trained survey teams, who
carried an introductory letter from the Ministry of Health
encouraging cooperation from parents. In each household visited,
one or two children aged 1 to 10 years were recruited into the
study. No eligible children refused to participate.
work was undertaken in December 1989, and January 1990. After
informed consent, details relating to age, sex and educational
status of each of the recruited children were recorded. In
addition, information was obtained with regard to the number of
children in the family, the position of the participant, the
occupation and the educational qualification of the father or
guardian. The investigators noted the type of house. Thereafter,
about 5 to 10 cc of blood was obtained by venesection from the
child. Serum samples were separated by centrifugation coded and
stored at –70 C until needed for testing. Antibody to hepatitis
A virus (anti-HAV) was detected using the ELISA kits from Abbott
Laboratory (Chicago, Illinois).
socioeconomic status of the child was taken as that of the
father or guardian and classified from the "socio-economic
score" derived from the type of house (mud- built or tent=1,
apartment or ordinary house=2, villa=3); the father’s education
(primary or grade school or less=1, secondary/high school=2,
university or professional qualification=3); father's occupation
(from 1 to 6) on the nature of work, e.g., labourer=1, and
trader=2, etc. A score of less than 4 from a maximum score of 12
was classified as low socioeconomic status, 5-8 as middle and
above 9 as upper class.
Chi-squared and Fisher’s exact test were used for comparison of
was positive in 52.4% of the 4375 children tested in the survey
(Table 1). The prevalence rates of anti-HAV in males (51.3% of
2358) and in females (53.5% of 2017) were not significantly
different. As shown in Figure 1, the age-specific rates were
similar in both sexes, with the lowest rate in infants with a
steady increase in the older age groups.
a marked regional variation in the anti-HAV prevalence (Table
1). Anti-HAV was lowest (38.4%) in the Eastern and and highest
(67%) in the Northwestern regions. In nearly all the regions,
rural inhabitants had a higher prevalence than urban residents
prevalence of HAV infection in high socioeconomic class was 35%,
middle class 48.5% and in low class 59%. Thus, socioeconomic
factors had a
Prevalence of anti-HAV according to sex and regions.
significant correlation with the prevalence of anti-HAV (P<0.001).
The level of education of parents had the strongest influence on
HAV prevalence, where university- educated parents had a
prevalence of 34%, secondary had 47.7% and primary or less
educated parents had 57.3% (P=0.001).
only a few community-based surveys on HAV infection and to the
best of our knowledge, this is the first such study in the
Middle East on children. The overall HAV prevalence of 52.4% in
children confirms that Saudi Arabia is endemic for HAV infection
despite the recent improvement in socioeconomic standards.
Although much higher than the reported rates (0-20%) in Western
Europe and North American children,13 the prevalence
of anti-HAV in Saudi Arabia is considerably less than the rate
of 96% reported from Algeria,14 or 50%-100%3,15,16
among African children.
Intraethnic and regional variations have been noted to occur in
the prevalence of hepatitis B virus (HBV), hepatitis D virus
(HDV), and recently hepatitis C virus (HCV) infections.12,17,19
It is therefore not surprising that the prevalence of anti-HAV
varied markedly from one region of Saudi Arabia to another. This
variation may be explained in part by the diversity in
socioeconomic standards despite the homogeneity of the
population in cultural practices and habits. The "border"
regions, e.g., the Northwestern and Southern provinces, have the
highest prevalence, suggesting the influence of the interaction
of the population with those of neighbouring countries with
endemic HAV. The roles of geographic location and socioeconomic
factors have been emphasized by different studies.1,2,13
been documented in earlier studies from different populations,
we found no relationship between anti-HAV and gender difference.3,6,20
An age-related increase of prevalence was apparent. The
prevalence of 36% in children under three years of age rose to
63.8% in those above seven years of age. This is in agreement
with earlier observations regarding the epidemiology of HAV in
the developing world, which is characterized by acquisition of
infection early in childhood.3,15,16 The higher HAV
prevalence among rural dwellers in Saudi Arabia is partly
explained by the difference in the nature of water supply. While
nearly all urban areas are supplied by water pipes from a
central reservoir, many villages depend on wells and tankers
delivering water supplies. Similar urban-rural differences have
been reported previously.3,13
main epidemiologic patterns of HAV exist worldwide.2
The first pattern is exemplified by the high endemicity in the
developing world where by adult age, 90% to 100% are anti-HAV
positive and, therefore, immune to infection. A second pattern
occurs in countries such as in Scandinavia, where, because of
high standards of hygiene and sanitation, HAV has been almost
eradicated from both the young and adult population.
Consequently, in the young a low prevalence and a relatively
high susceptibility to infection is characteristic and the
chances of HAV epidemics are relatively high. The third pattern
occurs in countries such as in Europe and North America, where
hygiene and sanitation have steadily improved over the years
and, therefore, the prevalence of HAV in the population is less
than 10%. In such circumstances, the incidence of HAV infection
declines and when infection occurs, it affects adolescents and
adults in whom there is associated clinical illness. Such a
pattern has been observed in countries such as China, Cuba and
Chile, in which major economic and social changes have occurred
in recent years. It is apparent
Saudi Arabia may be entering this transitional pattern.
been no national, community-based survey in Saudi Arabia with
which our findings could be compared to define the trend of HAV
infection in this population. However, a study of children
carried out in 198610 reported a prevalence of 56%
among Saudi children recruited from the Central Province. Our
study indicates that the rate in the same population had dropped
to 39% five years later. This suggests that the pattern of HAV
may be changing in Saudi Arabia. Such noticeable changes have
been noted in some countries.6,21,22
recent epidemic outbreak of hepatitis A virus among Saudi
children indicates an emergency for a highly susceptible
proportion of the population in parts of this country.23
Effective surveillance is mandatory in order to prevent further
reoccurrences. But since the majority of the population is
immune against hepatitis A due to mainly subclinical childhood
infection, a national vaccination program is not a priority now,
although the HAV vaccine has been proven to be immunogenic and
safe in preventing HAV infection in susceptible individuals.24
The need for the introduction of a hepatitis A vaccination will
be determined in the future definition of HAV epidemiology in
author wishes to thank Prof. Faleh Al Faleh and Prof. Banji
Ayoola for their assistance and Rajasingh Samuel for his
JL, Szmunees SV, Stevens CE, Purcell RH. Hepatitis A virus
infection: New insights from seroepidemiologic studies. J
Infectious Dis 1978; 137:328-40.
Feinstone SM. Hepatitis A. In: Progress in liver diseases.
Popper H, Schaffner, editors. Philadelphia: W.B. Saunders
Co., 1988; 371-8.
EA. Viral hepatitis in Africa. In: Viral hepatitis and liver
diseases. AJ Zuckerman, editor. New York: Alan R Liss,
Deinhardt F, Gust ID. Viral hepatitis.
World Hlth Org 1982; 60:66-9.
Mayed I, Lehmann NE, Dimitrikakis MA. A seroepidemiologic
study of infection with HAV and HBV in five Pacific Islands.
Am J Epidemiol 1979; 110:237-42.
Schenzle D, Deinhardt F, Scherd R. Epidemiology of hepatitis
A and B in the Shangai area: prevalence of serum markers. Am
J Epidemiol 1984; 120(3):404-13.
SJ, Arya SC, Parande CM, Kristensen E. Hepatitis A virus
among natives and expatriates in Saudi Arabia. J Med Urol
Shobokshi O, Serebour F, Abdulrahim SM. The prevalence and
pattern of hepatitis A viral infection in the Western region
of Saudi Arabia. Saudi Med J 1986; 7:402-8.
MAS, Walter DK, Nixon P, al Admoury AMO. Prevalence of
expatriates from various parts of the world working in Saudi
Arabia. J Infect 1983; 148:1167.
Antibody against hepatitis A in Saudi Arabians and in
expatriates from various parts of the world working in Saudi
Arabia. J Infect 1986; 12:153-5.
Faleh FZ, Ayoola EA, Arif M, et al.
Seroepidemiology of hepatitis B virus infection in Saudi
Arabian children: a baseline survey for mass vaccination
against hepatitis B. J infect 1992; 24:197-206.
Atlas of Kingdom of Saudi Arabia, King Saud University,
Riyadh; College of Arts - Department of Geography, 1981: 19.
Frosner GG, Papevangelou G, Butler R, et al.
against hepatitis A in seven Europen countries. A comparison
of prevalence data in different age groups. Am J Epidemiol
S, Ardjoun H. Epidemiology of viral hepatitis in Algeria.
Med Trop 1984: 44(3):247-52.
Nordenfelt E, Megesha B, Hansson BG, Tsega M, Lindberg J.
Age-specific prevalence of hepatitis A virus antibody in
Ethiopian children. Scand J Infect Dis 1990;22(2):145-8.
GT, Fresenius K, Frosner GG, Huber HC. Epidemiology of
hepatitis A and B and yellow fever in Zaire. Fortschr Med
1984; 102(40): 1019-21.
HC, Bradley AK, McLandilan K, et al. Hepatitis B virus
infection in two Gambian villages. Lancet 1983;1:1202-6.
GM, Brink BA, Conradie JD, Marimuthu T, Shet R. Regional
prevalence of hepatitis B, delta and human immunodeficiency
virus infection in Southern Africa. Am J Epidemiol 1989;
Faleh FZ, Ayoola EA, Jeffry M, et al.
Prevalence of antibody to hepatitis C virus among Saudi
Arabian children: a community-based study. Hepatology
Szmunes W, Dienstag JL, Purcell RH, et al.
prevalence of antibodies to hepatitis A antigen in various
parts of the world: a pilot study. J Epidemiol
Hushy HY, Chang MH, Chen DS et al.
seroepidemiology of hepatitis A virus infection in Taiwan. J
Med Virol 1985;17:297-301.
G, Willers H, Muller R, Schenzle D, Deinhardt F, Hopken W.
Decrease in incidence of hepatitis A infection in Germany.
SA, Bakir TMF, Al Aska A, Ayoola B. An outbreak of acute
hepatitis A infection in rural Saudi Arabia. Trop
Gastroenterol 1990; 11:202-5.
Aristegui J, Morales JL, Dal-Ri R, Gonzales A, Gallego MS,
Garrote E. Safety and immunogenicity of an inactivated
hepatitis-A vaccine in children 2 to 5 years old. Infection