Vol.3, No.1, 28-31 (2013) Open Journal of Preventive Medicine
Exposure of abattoirs workers to rift valley fever
virus infection in Southwestern Saudi Arabia
Tarik A. Al-Azraqi1, A wad A. El Mekki2, Ahmed A. Mahfouz3*
1Departments of Internal Medicine, College of Medicine, King Khalid University, Abha, KSA; tark4u2u@hotmail.com
2Departments of Clinical Microbiology, College of Medicine, King Khalid University, Abha, KSA;
3Departments of Community Medicine, College of Medicine, King Khalid University, Abha, KSA;
*Corresponding Author: mahfouz2005@gmail.com
Received 25 October 2012; revised 27 November 2012; accepted 5 December 2012
Objective: To measure seroprevalence of Rift
Valley Fever virus infection among abattoirs
workers in Southwestern Saudi Arabia. Materials
and Methods: Abattoirs in the region (Jazan,
Aseer and Al Qunfuda) were visited. Veterinari-
ans and butchers were studied. Blood samples
were then taken and tested for RVF-specific IgG
and IgM (ELISAs). Results: The present study
included 62 abattoir workers. None of whom
tested were positive for RVF specific IgM. The
overall prevalence of RVF IgG among butchers
reached 8% (95% CI: 1.3 - 75.8). Among the 31
Bengali butchers 3 were RVF IgG positive giving
a prevalence of 9.7 % (95% CI: 2.0 - 25.8), while
among four Saudi butchers one was RVF IgG
positive (25%, 95% CI: 1.3 - 75.8). Conclusions:
The study documented the lack of recent RVF
activity among abattoirs workers. High-risk, oc-
cupationally exposed abattoir workers represent
a useful sentinel population for surveillance of
RVF, especially in the absence of clinical dis-
Keywords: Rift Valley Fever; Sero-Epidemiologic
Studies; Abattoirs; Saudi Arabia
Rift valley fever virus infection (RFV) outbreaks have
been reported in the southern region of Saudi Arabia
[1,2]. By the end of the outbreak (22 September 2001)
the total number of hospitalized cases amounted to 884
of whom 843 were laboratory confirmed [3]. No RVF
outbreaks or human cases have been reported in the
Kingdom of Saudi Arabia since then.
Slaughterhouse work involves stressful and tiring
tasks. Those workers suffer from serious occupational
injuries and health problems including musculoskeletal
disorders, zoonoses, skin conditions and injuries related
to animals and sharp instruments. Studies in developed
countries showed that abattoir workers are generally low-
skill staff have no control over their job tasks and may
not be aware of the determinants affecting their health
The objective of the work was to estimate seropreva-
lence of Rift Valley Fever virus infection among abattoir
workers in Southwestern regions of Saudi Arabia.
2.1. Study Area
The study area (Figure 1) included Jazan, Aseer re-
gions and Al Qunfuda area in the Makkah region. Jizan
area is located in the southwest of Saudi Arabia, border-
ing the northwestern region of Yemen. The Aseer region
is located in the southwest of Saudi Arabia The region
extends from the high mountains of Sarawat to the Red
Sea, and lies few kilometers from the northern border of
neighboring Yemen. The Aseer region is bordering Jazan
and is located to its northeast. Al Qunfuda is a further
northward extension of this coastal plain in the Makah
region [5].
2.2. Study Population
Abattoirs within the study areas were identified.
Communication with preventive sectors in the concerned
directorate of health affairs and local municipalities were
made. Letters of approval (explaining the objectives of
the project and asking for their consent and cooperation)
were given to each abattoir director to ensure full coop-
eration. During late 2008 and through a series of field
trips, abattoirs were visited. Workers (Veterinarians,
butchers and clerks) present during the visit were in-
cluded in the study. Informed consents were obtained
from each individual to be included in the present study.
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T. A. Al-Azraqi et al. / Open Journal of Preventive Medicine 3 (2013) 28-31 29
Figure 1. Map of Saudi Arabia showing the study area; Jizan, Aseer and Al Qunfuda area.
2.3. Blood Sampling
About 5 - 10 ml venous Blood samples in plain tubes
were taken from each participant and were allowed to
clot at room temperature (range 18˚C to 20˚C). Samples
were then centrifuged at 10,000 rpm for 10 minutes and
the separated sera were alliquotted into 2 portions and
stored at 20˚C until transported in Styrofoam boxes
containing dry ice (solid carbon dioxide, 40˚C) to the
Virus Lab of Abha college of Medicine. All samples
were received there in a frozen state, and were grouped
by the area of collection and stored in classified boxes in
deep freezers at 20˚C.
2.4. Serologic Tests
Testing of Sera for RVF-Specific IgG and IgM
RVF kits were provided as bulk reagents to be further
processed prior to testing. The kit “RVF IgG ELISA”
(Batch # 2007-11), is manufactured, standardized and
provided by the National Institute of Communicable
Diseases, Special pathogens Unit, Johannesburg, South
Africa. All relevant reagents were supplied with the kits
including the controls. RVF-specific IgM assays were
performed utilizing kits from the supplier mentioned
above (RVF IgM ELISA, Batch # 2007-11). The manu-
facturer’s protocols were strictly followed in performing
and evaluating the results.
2.5. Statistical Analysis
Data were coded, validated and analyzed using SPSS
PC + version 13 software package. Frequency, percent-
age, arithmetic mean, median, mode and 95% confidence
intervals of the estimate were used to present the data.
3.1. Description of the Study Sample
The present study included 62 persons working in ab-
attoirs in the study regions (Table 1). They included 50
butchers (80.6%), 10 veterinarians (16.1%) and 2 clerk
workers (3.3%). Their age ranged from 19 years to 60
years with an average of 36.77 ± 10.29 years and a me-
dian of 35 years. The majority of butchers were Bengali
(31.62%), followed by Indians (5.10%), Saudis (4.8%)
Sudanese (4.8%) and Egyptians (3.6%). Veterinarians
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T. A. Al-Azraqi et al. / Open Journal of Preventive Medicine 3 (2013) 28-31
Table 1. Seroprevalence of RVF IgG among the study sample of abattoirs workers in Southwestern Saudi Arabia (N = 62).
Variables No. Examined % No. Positive Prevalence (%) 95% Confidence Interval
Occupation Group
Nationality of Butchers
2.8 - 17.4
1.8 - 15.7
1.3 - 75.8
2.0 - 25.8
were mostly Egyptians (8.80%) and Sudanese (2.20%).
The clerks were Saudis. The period of stay of non Saudis
in slaughter houses ranged from 3 year to 35 years with
an average of 10.38 ± 7.24 years and a median of 8 years.
The majority of workers (39, 62.9%) had no complaints
at all in the six months period prior to the survey. The
most frequent complaints were back pain (9, 14.5%) fol-
lowed by headache (4, 6.5%).
3.2. Sero-Prevalence of Rift Valley Fever
Virus Infection
3.2.1. Seroprevalence of RVF-Specific IgM
None of the 62 samples tested for Rift Valley Fever
IgM, were positive giving a Seroprevalence of zero %.
3.2.2. Seroprevalence of RVF-Specific IgG
Out of 62 samples tested for Rift Valley Fever IgG,
four samples were positive giving a Seroprevalence of
6.5%. The prevalence of RVF IgG among butchers
reached 8%. On the other hand, the prevalence among
veterinarians and clerk workers was zero percent. Among
the studied four Saudi butchers one was positive (25%).
Among the 31 Bengali butchers 3 were positive giving a
prevalence of 9.7%. On the other hand, none of the stud-
ied Egyptian, Sudanese and Indian butchers was found
positive. The study showed that the 4 positive cases of
Rift valley Fever IgG had no complaints at all in the past
6 months.
Abattoir workers and herdsmen are at a high risk of
acquiring RVF virus infection [6,7]. Among butchers in
the studied abattoirs, the RVF IgG seropositivity rate was
8%. This figure is higher than the overall seroprevalence
of 6.0% among community based general population
found in a recent study in the same region [8]. A sero-
prevalence figure of 7.3% was found among abattoirs
workers in Tanzania in 2004 before 2007 epidemics [9].
A higher rate of 40% has been documents among abattoir
workers in Kenya [7]. Again the higher rate in the Ken-
yan study could be attributed to cumulative previous
exposures to RVF virus. Interestingly, the seropositive
abattoir workers were all butchers, among whom the
seropositivity rate was 8%. This variability in prevalence
may also be explained by mere chance. The seropositive
butchers were a Saudi and three Bengalis and were resi-
dents of the study region during the outbreak of 2000-
2001. Only the Saudi recalled the fact that he was diag-
nosed as a case of RVFV infection and most likely the
remaining 3 were subclinically infected during the out-
break and none of the rest of the abattoir workers gave a
history of any illness during 6 past months. This argu-
ment is probably true since the entire sero-negative abat-
toir workers were appointed after the outbreak of 2000-
2001 and none of them was positive for RVF-specific
IgG or IgM thus ruling out any evidence of previous ex-
posure or recent infection.
While it is difficult to segregate slaughterhouse activi-
ties involving exposure to animal tissue, findings during
the 1993 outbreak in Egypt demonstrated that those tasks
with highest exposure to animal blood, i.e., cutting ani-
mals' throats and handling animal parts, were associated
with increased risk of infection with RVF virus. This
provides further evidence that direct contact with poten-
tially infected animals is a prominent mode of transmis-
sion of the virus [10].
The results of the present survey suggest that high-risk,
occupationally exposed abattoir workers represent a
useful sentinel population for surveillance of RVF, espe-
cially in the absence of clinical disease. Abattoir workers
in the study regions must adhere to protective measures.
Copyright © 2013 SciRes. OPEN ACCE SS
T. A. Al-Azraqi et al. / Open Journal of Preventive Medicine 3 (2013) 28-31 31
The present study documented a high prevalence of
RVF-specific IgG among those workers compared to the
general population. These protective measures should
include the wearing of masks, gloves, aprons and other
protective barriers. Regular use of soap, water and anti-
septics on exposed body parts should be encouraged
during their practices. The researchers observed the lack
of regular adherence of abattoir workers to these protec-
tive measures. More comprehensive training program in
the region for abattoir workers is needed. A recent study
in Portugal among butchers affirmed education as an
important link to the two variables: knowledge and atti-
tudes; customs and environment in abattoirs [11]. The
training programs for abattoirs workers in the region
should incorporate activities that support skills develop-
ment relevant to real life situations in which the workers
can put information into practice. There is a need to de-
velop training methods that proved to change behavior as
well as imparting knowledge.
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