The first serologic study of Q fever in sheep in Iran

Global and regional seroprevalence of coxiellosis in small ruminants: A systematic review and meta-analysis

BACKGROUND

Coxiellosis is a neglected zoonosis for occupationally exposed people in many parts of the world. Sheep and goats are two important small ruminants that act as reservoirs for human contamination; however, there is a lack of comprehensive data on the epidemiological aspects of coxiellosis in sheep and goats at regional and global levels. The aim of this study was to systematically review the available articles on seroprevalence of coxiellosis in sheep and goats and estimate the overall seroprevalence in different regions.

METHODS

A systematic search strategy was performed in five electronic repositories for articles published until December 2021. Relevant data were extracted from the selected articles based on the inclusion criteria. A random effect meta-analysis model was used to analyse the data. Results are presented as the prevalence of seropositivity as a percentage and 95% confidence intervals.

RESULTS

The global pooled seroprevalence of coxiellosis in sheep was 17.38% (95% confidence interval [CI]: 15.59%-19.17%). Overall, the regional level pooled prevalence estimates in sheep ranged from 15.04% (95% CI: 7.68%-22.40%) to 19.14% (95% CI: 15.51%-22.77%), depending on region. The global pooled seroprevalence of coxiellosis in goats was 22.60% (95% CI: 19.54%-25.66%). Overall, the regional level pooled prevalence estimates in goats ranged from 6.33% (95% CI: 2.96%-9.71%) to 55.13% (95% CI: 49.61%-60.65%), depending on the region. The prevalence estimates also varied significantly in both sheep and goats depending on age, sex, and rearing systems of the animals (p < 0.001).

CONCLUSION

Seroprevalence of coxiellosis in both sheep and goats is considerable. Routine monitoring of the sheep and goat populations is needed to prevent spillover infection in other livestock and humans.

Molecular and seroepidemiological investigation of Сoxiella burnetii and spotted fever group rickettsiae in the southern region of Kazakhstan

Ticks are involved in the circulation of a number of human pathogens, including spotted fever group (SFG) Rickettsia spp. and Coxiella burnetii. Little is known about the occurrence of these microorganisms in the southern region of Kazakhstan. In 2018-2022, a total of 726 ticks were collected from bitten humans, livestock, and vegetation in four oblasts of the southern region of Kazakhstan and subjected to DNA extraction. The overall infection rate of Coxiella spp. and Rickettsia spp. in the ticks was 3.3% (24/726) and 69.9% (300/429), respectively. Phylogenetic analysis of ompA and gltA genes revealed the presence of three pathogenic SFG rickettsiae: Candidatus R. tarasevichiae, R. aeschlimannii and R. raoultii in ticks collected from bitten humans. In addition, Candidatus R. barbariae was detected in six Rhipicephalus turanicus ticks for the first time in Kazakhstan. To determine the seroprevalence of C. burnetii infection, we performed a serological analysis of samples collected from 656 domestic ruminants (cattle, sheep, and goats) in the region. Overall, 23.5% (154/656) of the animals tested were positive for IgG against C. burnetii. Seroprevalence at the herd level was 54% (28/52). Goats (43%; 12/28; odds ratio (OD) = 28.9, p < 0.05) and sheep (31.9%; 137/430; OD = 18.1, p < 0.05) had higher seroprevalence than cattle (2.5%; 5/198). Among the risk factors considered in this study, age (p = 0.003) and the oblast in which the animals were sampled (p = 0.049) were statistically associated with seropostivity for Q fever in sheep, according to the results of multivariate logistic regression analysis. Seroprevalence ranged from 0% to 55.5% in animals in different districts of the southern region of Kazakhstan. Active C. burnetii bacteremia was detected in four of 154 (2.6%) seropositive animals. The data obtained provide strong evidence of the presence of pathogenic rickettsiae and C. burnetii in the southern region of Kazakhstan and emphasize the need to improve epidemiological surveillance in the region.

Serologic and molecular survey of horses to Coxiella burnetii in East of Iran a highly endemic area

There are few reports about Q fever in horse populations worldwide. This study aimed to detect the C. burnetii infection by serologic and molecular confirmation using commercial ELISA kit and real-time PCR in the East of Iran a region highly endemic. A total of 177 blood samples and 115 vaginal swabs were randomly collected from horses in East of Iran. The sera samples were analyzed for anti C.burnetii Ig G antibodies by a commercial ELISA kit and nucleic acid extraxted from vaginal samples were used to determine the C. burnetii DNA by real-time PCR assay. Antibodies were detected in 5.64 % (10/177) of sera samples and C. burnetii DNA was detected in 7.82 % (9/115) of horse vaginal samples. There was no significant difference in seroprevalence in different sex, age and breed groups. Our study showed that horses could be considered as a mild potential reservoir of C. burnetii which may be effective on horse health status. However, additional studies are needed to assess whether the horse could be considered as a relevant transmission risk indicator for Q fever.

Vector-borne diseases in Iran: epidemiology and key challenges

Vector-borne diseases have become a global health concern in recent decades as a result of global warming, globalization, growth in international trade and travel, use of insecticide and drug resistance. This review study addressed the key vector-borne diseases and their current status in Iran to emphasize the requirements for further research on vector-borne diseases. The dispersion patterns of these diseases differ in various regions. Some of them such as Crimean-Congo hemorrhagic fever, and Q fever are distributed all across Iran, whereas some others such as plague, leishmaniasis, tularemia, and malaria are restricted to specific areas. The high prevalence of vectors throughout the country necessitates enhancing the monitoring and surveillance of emerging and reemerging vector-borne diseases and their potential vectors.

Occurrence and risk factors of Coxiella burnetii in domestic ruminants in Lebanon

Coxiella burnetii causes diseases in humans (Q fever) and animals, domestic ruminants playing a major role in the epidemiology of the infection. Information on C. burnetii infection in Lebanon is scanty. In order to assess the prevalence of C. burnetii infection in ruminants, a cross-sectional study was undertaken in 2014. A total of 1633 sera from ruminants (865 cattle, 384 sheep and 384 goats) from 429 farms (173 cattle, 128 sheep and 128 goats), in seven provinces of Lebanon were randomly selected and assayed for the presence of antibodies. 39.86% of farms (95% CI: 35.23-44.56) resulted positive. The seroprevalence was 30.63% in Cattle-farms, 46.88% in sheep-farms and 45.31% in goat-farms. Milk samples collected from 282 seropositive animals (86 cows, 93 sheep and 103 goats) from 171 positive farms were tested by a high sensitive Real-Time PCR targeted to the IS1111 transposon of C. burnetii. The overall prevalence in farms was estimated to be 14.04%. Cattle-, sheep- and goat farm prevalence rates were 15.09%, 10% and 17.24%, respectively. The findings of the study show that C. burnetii prevalence in Lebanese domestic ruminants is related to animal species and farming practices. Indeed, the mixed herds with sheep (p < 0.01), the presence of common lambing/kidding areas (p < 0.001) in farms where the use of disinfectants was not a routine practice (p < 0.05) were identified as important risk factors. The results of the study provide baseline information for setting up herd management and public health measures for the prevention and control of Q fever in Lebanon.

Tick-borne zoonoses in the Order Rickettsiales and Legionellales in Iran: A systematic review

BACKGROUND

Tick-borne zoonoses in the Order Rickettsiales and Legionellales cause infections that often manifest as undifferentiated fevers that are not easy to distinguish from other causes of acute febrile illnesses clinically. This is partly attributed to difficulty in laboratory confirmation since convalescent sera, specific diagnostic reagents, and the required expertise may not be readily available. As a result, a number of tick-borne zoonoses are underappreciated resulting in unnecessary morbidity, mortality and huge economic loses. In Iran, a significant proportion of human infectious diseases are tick-borne, with anecdotal evidence suggesting that tick-borne zoonoses are widespread but underreported in the country. Epidemiological review is therefore necessary to aid in the effective control and prevention of tick-borne zonooses in Iran. The aim of this review is to provide an in-depth and comprehensive overview of anaplasmosis, ehrlichiosis, spotted fever group rickettsioses and coxiellosis in Iran.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, all relevant publications on tick-borne zoonoses in the Order Rickettsiales and Legionellales in Iran were searched using a number of search terms. The search was confined to authentic resources from repositories of popular data bases among them PubMed, Web of Science, Google Scholar, Science Direct, SpringerLink and SCOPUS. The search items included peer reviewed journals, books and book chapters published between 1996 and 2017.

RESULTS

A total of 1 205 scientific publications and reports were sourced, of which 63 met the search criteria and were reviewed. Of the 63 articles reviewed, 36 (57.1%) reported on coxiellosis, 15 (23.8%) on anaplasmosis, 11 (17.5%) on ehrlichiosis and 1(1.6%) on spotted fever group rickettsiae in a large scale study involving four countries, among them Iran. The existence of tick-borne pathogens in the Order Rickettsiales and Legionellales was confirmed by molecular, serological and microscopic techniques conducted on samples obtained from sheep, cattle, goats, camels, poultry, animal products (milk and eggs), dogs, ticks and even human subjects in different parts of the country; pointing to a countrywide distribution.

DISCUSSION

Based on the review, coxiellosis, anaplasmosis, ehrlichiosis, and SFG rickettsiae can be categorized as emerging tick-borne zoonotic diseases in Iran given the presence of their causiative agents (C. burnetii, A. phagocytophilum, A. marginale, A. bovis, A. ovis, A. central, E. canis, E. ewingii, E. chaffeensis and R. conorii) collectively reported in a variety of domestic animals, animal products, arthropods and human beings drawn from 22 provinces in Iran.

CONCLUSION

Given the asymptomatic nature of some of these zoonoses, there is a high likelihood of silent transmission to humans in many parts of the country, which should be considered a public health concern. Presently, information on the transmission intensity of tick-borne zoonoses caused by pathogens in the Order Rickettsiales and Legionellales to humans and its public health impact in Iran is scanty.

Epidemiology of Q fever in Iran: A systematic review and meta-analysis for estimating serological and molecular prevalence

Background:

Q fever is endemic in Iran, thus, we conducted a systematic review and meta-analysis on epidemiology of Coxiella burnetii among humans and animals in Iran.

Materials and Methods:

A systematic search was performed to identify all articles reporting C. burnetii prevalence in Iranian humans or animals, published from January 2000 to January 2015. Data from articles were extracted, and a pooled estimate of prevalence with corresponding 95% confidence interval (CI) was calculated using random effect method.

Results:

In this review, 27 papers were identified. The pooled seroprevalence of Q fever in animals was 27% (CI 95%: 23%–32%). The prevalence was 33% (CI 95%: 22%–45%) in goats, 27% (CI 95%: 21%–32%) in sheep, and 17% (CI 95%: 5%–28%) in cattle. The bacterial DNA was detected in 5% (95% CI: 3%–9%) of milk samples, and it was higher in cattle (10%; 95% CI: 6%–16%) than sheep (2%; 95% CI: 0–7%) and goats (4%; 95% CI: 0–12%).

Conclusion:

C. burnetii DNA or its antibody has been frequently detected among ruminants. Since these animals can transmit the infection to humans, Q fever could be a potential health problem in Iran.

Cross-sectional study for determining the prevalence of Q fever in small ruminants and humans at El Minya Governorate, Egypt

Objective

Q fever is a febrile illness caused by the bacterial pathogen Coxiella burnetii (C. burnetii) and is transmitted to humans from small ruminants via contaminated secreta and excreta of infected animals. This pathogen threatens public health; however, little is known regarding Q fever prevalence in humans and small ruminants. Therefore, we employed a cross-sectional design to determine the Q fever seroprevalence and the associated risk factors in small ruminants and their owners in El Minya Governorate, Egypt between August 2016 and January 2017.

Results

The seroprevalence of C. burnetii IgG antibodies was 25.68% (28 of 109), 28.20% (11 of 39) and 25.71% (9 of 35) in sheep, goats, and humans, respectively. None of the studied variables in small ruminants differed significantly between the seropositive and seronegative animals. There was a significantly higher prevalence (P = 0.0435) and increased odds of exposure was also observed among women (odds ratio, OR = 5.43 (95% CI 1.058–27.84) when compared to men; nevertheless, no significant difference was noted between the infection rate in small ruminants and humans. This study clearly points out that Q fever may be emerging in the area which lay the foundation for early prediction and better management of possible future outbreaks.

Electronic supplementary material

The online version of this article (10.1186/s13104-017-2868-2) contains supplementary material, which is available to authorized users.

Seroprevalence of Q fever among human and animal in Iran; A systematic review and meta-analysis

BACKGROUND

Q fever is a main zoonotic disease around the world. The aim of this meta-analysis was to estimate the overall seroprevalence of Coxiella burnetii among human and animal population in Iran.

METHODS

Major national and international databases were searched from 2005 up to August 2016. We extracted the prevalence of Q fever antibodies (IgG) as the main primary outcome. We reported the prevalence of the seropositivity as point and 95% confidence intervals.

RESULTS

The overall seroprevalence of IgG phase I and II antibodies of Q fever in human was 19.80% (95% CI: 16.35-23.25%) and 32.86% (95% CI: 23.80-41.92%), respectively. The herd and individual prevalence of C. burnetii antibody in goat were 93.42% (95% CI: 80.23-100.00) and 31.97% (95% CI: 20.96-42.98%), respectively. The herd and individual prevalence of Q fever antibody in sheep's were 96.07% (95% CI: 89.11-100.00%) and 24.66% (95% CI: 19.81-29.51%), respectively. The herd and individual prevalence of C. burnetii antibody in cattle were 41.37% (95% CI: 17.88-64.86%) and 13.30% (95% CI: 2.98-23.62%), respectively. Individual seropositivity of Q fever in camel and dog were 28.26% (95% CI: 21.47-35.05) and 0.55% (0.03-2.68), respectively.

CONCLUSION

Seroprevalence of Q fever among human and domestic animals is considerable. Preventative planning and control of C. burnetii infections in Iran is necessary. Active surveillance and further research studies are recommended, to more clearly define the epidemiology and importance of C. burnetii infections in animals and people in Iran.

Seroprevalence of Q Fever (Coxiellosis) in Small Ruminants of Two Districts in Punjab, Pakistan

Coxiellosis caused by Coxiella burnetii is a cosmopolitan zoonosis, which causes significant losses through abortions and stillbirths in small ruminants. A cross-sectional seroprevalence study was conducted in two major sheep and goat farming districts of Punjab (Layyah and Muzaffargarh), Pakistan. In total, 542 small ruminants (271 sheep and goats each) of both sexes (60 males and 482 females) of different age groups from 104 flocks (52 flocks of either species) were randomly selected for the collection of sera and related epidemiological information. The sampling plan was devised at the expected prevalence of 50%, confidence interval (CI) of 95%, and error margin of 5%. A commercial indirect enzyme-linked immunosorbent assay (iELISA; ID Vet) was used to test the samples for the presence of both phase I and II antibodies. A high herd level prevalence (73.1%, 95% CI 63.5-81.3) was recorded in the studied districts. Individual level seroprevalence was recorded as 30.8% (95% CI 26.9-34.9). Higher value was recorded in females (32%) when compared with males (21.7%). Higher prevalence (34.8%, 95% CI 21.4-50.2) was observed in animals of 1 year (nulliparous) than to primiparous (24.8%, 95% CI 17.4-33.5) and multiparous (32.3%, 95% CI 27.6-37.3) animals. Univariable analysis indicated that caprine species (odds ratio [OR] 1.96, p = 0.22), females (OR = 1.70, p = 0.104), infestation with ticks (OR = 234.39, p < 0.001), abortion history (OR 1.96, p = 0.14), retention of fetal membranes (OR 1.50, p = 0.35), keeping a single breed in a herd (OR 1.50, p = 0.56), and mixed feeding management (OR 1.37, p = 0.33) were the variables found associated with high prevalence of antibodies to C. burnetii. The study indicates that seroprevalence of coxiellosis was high in the studied small ruminant population and further studies are required to discern its epidemiology more precisely.

Seroepidemiological study of Q fever in small ruminants from Southeast Iran

The aim of the present study was to determine the prevalence of Coxiella burnetii antibodies in small ruminants in Southeast Iran. A total of 368 small ruminant blood samples (241 caprine blood samples and 127 ovine blood samples) were collected from January to May of 2011 in Southeast Iran. A commercial ELISA test kit was employed to identify specific antibodies against C. burnetii in the sheep and goats. Seropositivity in the examined counties ranged from 17.1% to 39.2%. Of the animals tested, 97 animals (26.4%), including 43 sheep (33.9%) and 54 goats (22.4%), had antibodies to C. burnetii. The results of the current study reveal the high prevalence of antibody positivity in small ruminants in Southeast Iran. Thus, sheep and goats are important reservoirs in this area. Additionally, we performed a logistic regression to the identify risk factors for positivity and concluded that age was an important risk factor (P<0.001).

Serologic survey for Coxiella burnetii phase II antibodies among slaughterhouse workers in Kerman, southeast of Iran

OBJECTIVE

To determine the presence of antibodies against phase II among slaughterhouse workers in Kerman, southeast of Iran.

METHODS

The antibody titers of the serum samples were measured by enzyme-linked immuno sorbent assay using phase II Coxiella burnetii as the antigen [kit (Virion\Serion, Wurzburg, Germany) according to the manufacturer's protocol].

RESULTS

The positive rate of IgG antibody was 68% in the slaughterhouse workers.

CONCLUSIONS

Our findings suggest that slaughterhouse workers in Kerman area have a higher risk of infection and should consider potential infection with Coxiella burnetii.

The prevalence of Coxiella burnetii infection in wild Korean water deer, Korea

The aim of this study was to evaluate the prevalence of Coxiella burnetti infection in wild Korean water deer (Hydropotes inermis argyropus) in Korea, by using serology and real-time PCR analyses. One hundred ninety-six sera were collected from 4 provinces and tested for anti-C. burnetii antibody detection, by means of CHEKIT Q fever ELISA kit; and C. burnetii IS1111 insertion sequence detection, by means of real-time PCR. Antibodies were detected in 18 of the 196 (9.18%) serum samples, whereas genomes of C. burnetii were detected in 13 of the 196 (6.63%) serum samples. Based on overall high seroprevalence, the public health implications of these findings are important, because they indicate that asymptomatic seropositive or seronegative wild animals may be consistently shedding C. burnetii. This is the first study of C. burnetii prevalence in Korean water deer in the Republic of Korea that has indicated the presence of infected animals throughout the country.

Seroprevalence survey of Q fever among sheep in northwestern Iran

Q fever is a disease caused by Coxiella burnetii, which infects both humans and certain animals, and is considered a public health problem. There is a lack of information on its status in most parts of Iran, including the northwestern area, which is one of the main centers of animal husbandry in Iran. This study was carried out to evaluate the seroprevalence of Q fever among sheep in the province of Ardabil in northwestern Iran. In all, 253 sheep samples were collected from different regions (north, central, and south) of Ardabil Province. Sera were tested by a CHEKIT Q fever enzyme-linked immunosorbent assay (ELISA) kit for detection of C. burnetii immunoglobulin G (IgG). A total of 33.6% of sheep sera and 87.50% of herds were positive for C. burnetii IgG. There was a significant difference between the regions studied (p<0.001) and the highest and the lowest rate of seroprevalence were seen in the south (58.6%) and central (23.3%) regions, respectively. Most of the seropositive cases were observed in 3- to 4-year-old the sheep (46.1%). There was no relationship between gender and the seroprevalence rate. Although this study was the first survey of Q fever in northwestern Iran, the high seroprevalence rate indicates that further attention should be paid to this disease in this region of the country.

Seroepidemiological survey of Q fever and brucellosis in Kurdistan Province, western Iran

Given that the there is little information about the current status of brucellosis and Q fever in most parts of Iran, the aim of this study was to assay the seroprevalence of these two diseases in high-risk populations of Kurdistan Province in western Iran. Two hundred fifty sera samples were collected from hunters and their families, butchers, health care workers, and those referred to medical diagnostic laboratories in the southwestern regions of Kurdistan Province. Sera were tested to detect specific immunoglobulin G (IgG) antibodies against brucellosis and Coxiella burnetii (phase I and II). The seroprevalence of brucellosis and Q fever (C. burnetii IgG phase I and II) was 6.4% and 27.83% (20% and 14.52%), respectively. The highest seroprevalence of Q fever (38%) and brucellosis (12%) was seen in butchers, who handled cattle, sheep, and goats during their work. Age had a significant positive association with Q fever seropositivity (p=0.04). The seroprevalence of Q fever was higher in those people who had been in employment for more than 10 years (21.88%) compared to others (7.79%) (p=0.02). The keeping of animals (p=0.03), hunting and eating the meat of wild animals (p=0.02), and not disinfecting hands and faces after working (for health care workers and butchers) (p=0.02) were risk factors for Q fever seropositivity. This study showed a relatively high seroprevalence of brucellosis and Q fever in high-risk populations of Kurdistan Province. It is suggested that complementary studies be carried out in other parts of western Iran to clarify the epidemiological aspects of these diseases.