The prevalence of Q fever in the Eastern Mediterranean region: a systematic review and meta-analysis

OBJECTIVES

Q fever, caused by the bacterium, is a major zoonotic disease around the world. This disease is common in the Eastern Mediterranean region; therefore, we conducted the first systematic review and meta-analysis on its prevalence in humans, animals, and ticks in the Eastern Mediterranean region.

METHODS

Major Iranian and international databases were searched from 2000 to 2021. We extracted the prevalence of Q fever in blood samples from animals and milk samples from animals, ticks, and humans as the main outcome. We reported the prevalence of seropositivity and molecular positivity as point estimates and 95% confidence intervals (CIs).

RESULTS

In this review, 112 papers were identified. The overall seroprevalence of Q fever was 22.4% (95% CI, 19.8 to 25.1). The pooled prevalence of Q fever in ticks was 17.5% (95% CI, -1.3 to 36.4). The prevalence was 25.5% (95% CI, 16.1 to 34.9) in humans. The prevalence of Q fever in animal blood samples from goats, sheep, camels, cattle, cats, dogs, horses, and buffalo were 28.1%, 25.1%, 25.0%, 20.1%, 9.8%, 8.4%, 6.5%, and 6.3%, respectively. Furthermore, the prevalence of Q fever in milk samples of animals was higher in cattle (20.3%) than in sheep (20.0%), goats (16.4%), and camels (3.3%).

CONCLUSIONS

Coxiella burnetii infections are common in humans and in a wide range of animal species, but they are still not recognized in many countries in the Eastern Mediterranean region, thus presenting a significant threat to human and animal health in the region.

A Review on Important Zoonotic Bacterial Tick-Borne Diseases in the Eastern Mediterranean Region

Background

Zoonotic diseases as health concerns worldwide account for more than half of the emerging infectious diseases. Arachnids are powerful vectors to transmit several diseases to humans. Additionally, these emerging zoonotic diseases have been a considerable health threat in the Eastern Mediterranean Region of the WHO (EMRO) due to the large population living close to farms and international trade with nearby countries.

Methods

This review study is based on the reported three tick-borne diseases, Lyme disease, Tularemia, and Q fever, from Iran and other EMRO countries. To this end, we searched PubMed central, ISI web of Science, and Google with the related keywords in English at any time. The reported data are then sorted by countries for each disease.

Results

According to the published data, 15 countries in the region have one/more emerging infectious diseases. Q fever has been the most frequent infection in EMRO countries, while Lyme was less recorded. Furthermore, Iran is among the countries with documented history of all three investigated diseases.

Conclusion

Tick-borne disease is popular among EMRO countries, indicating that they have natural conditions for infections in animals and humans. It appears necessary to develop a disease management strategy and control programs against tick-borne diseases (TBDs). Moreover, the disease-resistant animal could be bred instead of susceptible livestock. Therefore, research studies to control TBDs should be regarded as a top priority plan.

Seroprevalence of Q fever among high-risk occupations in the Ilam province, the west of Iran

Background

Q fever is a zoonotic disease of great public health importance in Iran. This disease is presented with high phase I antibody development in chronic and high phase II antibody in the acute form of illness. This study was conducted to evaluate the seroprevalence of Q fever among high-risk occupations in the Ilam province in Western Iran.

Methods and findings

In this cross-sectional study, 367 sera samples were collected from five groups comprised of animal husbandry workers, farmers, butchers, slaughterhouse workers, and park rangers. The collected sera were tested for IgG antibodies against Coxiella burnetii using ELISA. The seroprevalence of antibodies against C. burnetii in phase I and II was 24.38% and 26.37%, respectively (i.e., 32.42% overall). Low educational level, living in rural areas, keeping sheep/goats, ages older than 50 years, and a history of arthropod bites positively correlated with increased risk of Q fever infection. Animal husbandry workers (45.13%) were at higher risk of contracting Q fever compared with other occupations in the study (17.11%).

Conclusions

High seroprevalence of C. burnetii among high-risk occupations is a serious challenge in the Ilam province. In addition, the high seroprevalence of endemic Q fever in rural and nomadic areas and a higher concentration of occupations who are directly engaged with livestock demonstrate the critical need for preventive medicine education and training in regards to mitigating risk for disease contraction in susceptible groups.

Remembering Marcel Baltazard, Great Researcher and the French President of Pasteur Institute of Iran

Dr. Marcel Baltazard (1908-1971), French scientist and former director of Pasteur Institute of Iran, is known in the international arena due to his research on the control of infectious diseases such as plague, rabies, relapsing fever, leprosy, smallpox and tuberculosis. Dr. Baltazard also played a significant role in the launch of vaccination against tuberculosis, cholera and smallpox. Dr. Baltazard's spent the first 13 years of academic life at Pasteur Institute of Casablanca, Morocco, and then 20 years at Pasteur Institute of Iran and over the last five years at Pasteur Institute of Paris. In this paper, the activities of this important and influential researcher in the field of health and medicine are addressed.

Synergistic effect of aged garlic extract and naltrexone on improving immune responses to experimentally induced fibrosarcoma tumor in BALB/c mice

Background:

Garlic, a medicinal plant, and Naltrexone (NTX), an opioid receptor antagonist, both have immunomodulatory and antitumor effects. Current study was designed to evaluate synergistic antitumor effects of aged garlic extract (AGE) and NTX.

Materials and Methods:

WEHI-164 fibrosarcoma cells were implanted subcutaneously on day 0 into right flank of 80 BALB/c mice at age of 8 weeks. Mice were randomly categorized in four separate groups: The first group received AGE (100 mg/kg, i.p.), the second group received NTX (0.5 mg/kg, i.p.), the third group received both of them, and the fourth group received phosphate buffered saline as control group. Treatments were administered three times per week. Tumor growth was measured and morbidity was recorded. Subpopulations of CD4+/CD8+ T cells were determined using flowcytometery. WEHI-164 cell specific cytotoxicity of splenocytes and in vitro production of interferon-gamma (IFN-γ) and interleukin-4 (IL-4) cytokines were measured. All statistical analyses were conducted with SPSS 16 software and P < 0.05 was considered to be statistically significant.

Results:

The mice who received AGE+NTX had significantly longer survival time compared with the mice treated with AGE or NTX alone. An enhanced inhibitory effect on tumor growth was seen in combination therapy group. The CD4+/CD8+ ratio and in vitro IFN-γ production of splenocytes were significantly increased in AGE+NTX and NTX groups. WEHI-164 specific cytotoxicity of splenocytes was also significantly increased at 25:1 E:T ratio in AGE+NTX treated mice. Coadministration of AGE with NTX resulted in improvement of immune responses against experimentally implanted fibrosarcoma tumors in BALB/c mice.

Conclusions:

AGE showed synergistic effects with NTX on inhibition of tumor growth and increment of survival times.

Immunomodulatory activity of aged garlic extract against implanted fibrosarcoma tumor in mice

Background:

Garlic is known as a medicinal herb with broad therapeutic properties ranging from antibacterial to anticancer and even anticoagulant.

Aim:

Current study was designed to evaluate antitumor effects of aged garlic extract (AGE) on fibrosarcoma tumor in BALB/c mice.

Materials and Methods:

WEHI-164 fibrosarcoma cells were implanted subcutaneously on day zero into right flank of 40 BALB/c mice aged eight weeks. Mice were randomly categorized in two separate groups: 1^st received AGE (100 mg/kg, intraperitoneally), 2^nd group as control received phosphate buffered saline, (PBS). Treatments were done three times per week. Tumor growth was measured and morbidity was recorded. Subpopulations of CD4+/CD8+ T cells were determined using flow cytometry. WEHI-164 cell specific cytotoxicity of splenocytes and in vitro production of gamma-interferon, (IFN-γ) and Interleukin-4, (IL-4) cytokines were measured.

Results:

The mice received AGE had significantly longer survival time compared to control mice. The inhibitory effect on tumor growth was seen in AGE treated mice. The CD4+/CD8+ ratio and in vitro IFN-γ production of splenocytes were significantly increased in AGE group.

Conclusions:

Administration of AGE resulted in improved immune responses against experimentally implanted fibrosarcoma tumors in BALB/c mice. AGE showed significant effects on inhibition of tumor growth and longevity of survival times.

HLA-DRB1, DQA1 and DQB1 alleles and haplotypes frequencies in Iranian healthy adult responders and non-responders to recombinant hepatitis B vaccine

BACKGROUND

Different studies have demonstrated that a small proportion of healthy individuals receiving the hepatitis B (HB) vaccine do not produce protective levels of anti-HB antibody, a phenomenon which could be linked to certain human leukocyte antigen (HLA) class-II alleles or haplotypes.

OBJECTIVES

The present study was undertaken to determine the frequency of HLA class-II alleles in Iranian healthy adult responders and non-responders to HB vaccine.

METHODS

Twelve non-responders (anti-HBs antibody<10 IU/L) and 46 responders (anti-HBs antibody>100 IU/L) were tissue typed for HLA class-II. HLA-DRB1, DQB1 and DQA1 alleles were determined using polymerase chain reaction based on sequence specific primers (PCR-SSP) technique. Accessibility to excess amount of genomic DNA was possible using Epstein-Barr virus (EBV)-transformed B-cells established from all vaccinees.

RESULTS

Our results demonstrated increased frequencies of HLA- DRB107, DRB103, DRB104, DQB10201, DQA10201 alleles and HLA- DRB107/DQB10201/DQA10201 and DRB104/DQB10302/DQA103011 haplotypes in the non-responder group. Comparison between responders and non-responders revealed only a significant difference for DQB10201 allele (p<0.05).

CONCLUSION

These findings confirm the association of certain HLA alleles and haplotypes with the lack of antibody response to HB vaccine in an Iranian population.