Seroepidemiological study of Q fever in small ruminants from Southeast Iran

Molecular detection of Coxiella burnetii in tick and blood samples from small ruminants in northwest of Iran

This survey sought to molecularly detect Coxiella burnetii in Argasidae and Ixodidae ticks attached to small ruminants in the region of West Azerbaijan (Northwest of Iran) and blood samples collected from the same animals. 451 tick samples and 927 blood samples were obtained from sheep (n = 536) and goats (n = 391) and tested by nested PCR for detection of C. burnetii insertion sequence IS1111 or icd gene sequence. The collected ticks were morphologically classified as Rhipicephalus sanguineus, Rhipicephalus turanicus, Hyalomma asiaticum, Hyalomma anatolicum, or Argas reflexus. 14% of ticks (65 in total 43 for IS1111 and 22 for icd gene) tested positive for C. burnetii, none of which were from the Argas genus. Among the 927 blood samples, 218 (23.5%) tested positive for C. burnetii. The positive result from analysis targeting the genes IS1111 and icd were 131 and 87 respectively. As Q fever is a tickborne zoonosis and endemic to Iran, such information is critical for creating effective, coordinated, and strategic tick and pathogen control programs to prevent disease outbreak in domestic animals and humans.

Role of Goats in the Epidemiology of Coxiella burnetii

Since its first description in the late 1930s, Q fever has raised many questions. Coxiella burnetii, the causative agent, is a zoonotic pathogen affecting a wide range of hosts. This airborne organism leads to an obligate, intracellular lifecycle, during which it multiplies in the mononuclear cells of the immune system and in the trophoblasts of the placenta in pregnant females. Although some issues about C. burnetii and its pathogenesis in animals remain unclear, over the years, some experimental studies on Q fever have been conducted in goats given their excretion pattern. Goats play an important role in the epidemiology and economics of C. burnetii infections, also being the focus of several epidemiological studies. Additionally, variants of the agent implicated in human long-term disease have been found circulating in goats. The purpose of this review is to summarize the latest research on C. burnetii infection and the role played by goats in the transmission of the infection to humans.

Seroepidemiological study on Coxiella burnetii and associated risk factors in ruminants at Kurdistan Province, west of Iran

Q fever is zoonotic disease caused by Coxiella burnetii. Ruminants are the main reservoir of this pathogen, which is often asymptomatic but lead to abortion. This study aims to survey the seroprevalence and risk factors of this zoonose among ruminants in Kurdistan province, the west of Iran. 480 blood samples were collected from ruminants including sheep, goats and cows, each 160 samples, in the age groups of <1, ≥1-3, >3-5 year with and without the history of abortion in two groups border and non-border cities in Kurdistan province. Serums were tested by use of indirect ELISA to determine specific antibodies against C. burnetii. The results indicate the seroprevalence of 46.6 % for Q fever. Seroprevalence in sheep, goats and cows were 28.58 % (n = 64), 45.53 % (n = 102) and 25.89 % (n = 58), respectively. Seroprevalence is significantly higher in animals with abortion than in those without such history (P < 0.05). The seroprevalence in the border cities has been significantly higher than other geographical areas (P < 0.05). Seroprevalence had no significant correlation with animal age (P> 0.05). This study is the first seroepidemiological study done on Q fever in ruminants of Kurdistan province, Iran. The results indicate the high seroprevalence of Coxiella burnetii in the area under the study. Therefore, doing an epidemiologically study aimed at isolating C. brunetii in the human population of Kurdistan province is recommended, so that the epidemiological aspect of this pathogen in the people of Kurdistan province be clarified and subsequently disease control and prevention programs be applied.

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.

Prevalence of C. burnetii DNA in sheep and goats milk in the northwest of Iran

Q fever is a common zoonotic disease with worldwide distribution. The causative agent of Q fever is Coxiella burnetii, a gram-negative and polymorphic rod bacterium. Sheep and goats are the primary reservoirs of this disease, although a variety of animal species can be infected. The main route of Q fever transmission from animals to humans is the inhalation of contaminated aerosols with C. burnetii. The bacterium is excreted in milk of infected animals and therefore; the consumption of unpasteurized milk and dairy products might be a route of coxiella burnetii transmission from animals to humans. The present study was conducted to determine the prevalence of C. burnetii in milk samples collected from sheep and goats in west Azerbaijan province, Iran. During 2018, a total number of 420 milk samples were collected from sheep (n = 210) and goats (n = 210) of different regions of the province. All milk samples were subjected to DNA extraction and examined by a highly and specific nested-PCR method. The results showed that 51 (12.1%) (95% CI: 9.3%-15.6%) examined samples [sheep; n = 16 (7.6%) and goat; n = 35 (16.6%)] were positive for C. burnetii. The prevalence of C. burnetii in goat milk samples was significantly higher than sheep milk samples (P < 0.05). The shedding of C. burnetii in milk was significantly higher in summer (25%) (P < 0.05, 95% CI: 17.7%-34%) than the other seasons. It was concluded that sheep and goat populations in west Azerbaijan play an important role in the epidemiology of Q fever.

Seroprevalence and associated risk factors of Coxiella burnetii (Q fever) in goats and sheep in northern Jordan

This cross-sectional study aimed to study animal, farm, and within-farm seroprevalence of C. burnetii and to identify associated risk factors in goat and sheep farm in northern Jordan. Questionnaire was developed to collect information about risk factors and farms management practices. Blood samples from 730, ≥ 1-year-old females (goat n = 250; sheep n = 480) were randomly collected from 20 goat herds and 40 sheep flocks. IDEXX ELISA Kit was used to detect C. burnetii antibodies. The overall goat and sheep seroprevalence level was 32.5% (237/730) and was significantly higher in goats (43.3%, 108/250; 95% CI 37-49.6) than sheep (27%, 129/480; 95% CI 29.1-36.2) (χ2 test, p ≤ 0.001). Eighty percent (16/20) of goat herds and 60% (24/40) of sheep flocks had at least one seropositive animal (p ≥ 0.05). The average within goat herds and sheep flock seroprevalence were 36.4% (ranged: 0-91%) and 23.4% (ranged: 0-82%), respectively. Multivariate logistic regression model revealed that seroprevalence increased 1.79 times in goat herds compared with sheep flocks, 3.2 times more in farms containing ≥ 100 animals, and 1.7 times higher in farms with their animals that were ≥ 2 years of age than in farms with their animals that are < 2 years of age. In addition, seroprevalence significantly increased 1.52 times in farms loaning bucks or rams during breeding season and 1.63 times in farms containing cats on premises (p ≤ 0.05). Farm biosecurity measures are essential to prevent introduction and minimize transmission of C. burnetii infection to humans and animals.

Serological and Molecular Investigation of Coxiella burnetii in Small Ruminants and Ticks in Punjab, Pakistan

Coxiellosis is a zoonotic disease caused by the obligate intracellular bacterium Coxiella burnetii affecting the productive and reproductive capabilities of animals. This study was conducted to gain insight into the seroprevalence of coxiellosis in small ruminants in seven farms of the Punjab, Pakistan. Potential risk factors were assessed. In total, 1000 serum samples (500 from sheep and 500 from goats) and 163 ticks were collected from the ruminants. All these 163 ticks were merged into 55 pools (29 pools for ticks from sheep and 26 pools for ticks from goat). Serum samples were investigated using an indirect ELISA and PCR. Coxiella burnetii DNA was detected in 29 pooled seropositive samples and 11 pooled ticks by real-time qPCR. Serological analysis revealed a prevalence of 15.6% and 15.0% in sheep and goats, respectively. A significant association was found between seropositivity and different variables like district, lactational status, reproductive status, body condition and reproductive disorders. Univariate analysis showed that detection of C. burnetii DNA in tick pools was significantly associated with the presence of ticks on sheep and goats. However, a non-significant association was found for the prevalence of C. burnetii DNA in serum pools. Hence, C. burnetii infection is prevalent in small ruminants and ticks maintained at livestock farms in Punjab, Pakistan.

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.