Immunogenicity and safety of heterologous boost immunization with PastoCovac Plus against COVID-19 in ChAdOx1-S or BBIBP-CorV primed individuals.

BACKGROUND: This study aimed at evaluation and comparison of PastoCovac Plus protein-subunit vaccine in parallel with ChAdOx1-S (AstraZeneca) and BBIBP-CorV (Sinopharm) in primarily vaccinated volunteers with two doses of ChAdOx1-S or BBIBP-CorV. MATERIALS AND METHODS: 194 volunteers enrolled the study who were previously primed with 2 doses of ChAdOx1-S or BBIBP-CorV vaccines. They were divided into two heterologous regimens receiving a third dose of PastoCovac Plus, and two parallel homologous groups receiving the third dose of BBIBP-CorV or ChAdOx1-S. Serum samples were obtained just before and 4 weeks after booster dose. Anti-spike IgG and neutralizing antibodies were quantified and the conventional live-virus neutralization titer, (cVNT50) assay was done against Omicron BA.5 variant. Moreover, the adverse events data were recorded after receiving booster doses. RESULTS: ChAdOx1-S/PastoCovac Plus group reached 73.0 units increase in anti-Spike IgG rise compared to the ChAdOx1-S/ ChAdOx1-S (P: 0.016). No significant difference was observed between the two groups regarding neutralizing antibody rise (P: 0.256), indicating equivalency of both booster types. Adjusting for baseline titers, the BBIBP-CorV/PastoCovac Plus group showed 135.2 units increase (P<0.0001) in anti-Spike IgG, and 3.1 (P: 0.008) unit increase in mean rise of neutralizing antibodies compared to the homologous group. Adjustment for COVID-19 history, age, underlying diseases, and baseline antibody titers increased the odds of anti-Spike IgG fourfold rise both in the ChAdOx1-S (OR: 1.9; P: 0.199) and BBIBP CorV (OR: 37.3; P< 0.0001) heterologous groups compared to their corresponding homologous arms. The odds of neutralizing antibody fourfold rise, after adjustment for the same variables, was 2.4 (P: 0.610) for the ChAdOx1-S heterologous group and 5.4 (P: 0.286) for the BBIBP CorV heterologous groups compared to their corresponding homologous groups. All the booster types had the potency to neutralize BA.5 variant with no significant difference. The highest rate of adverse event incidence was recorded for ChAdOx1-S homologous group. CONCLUSIONS: PastoCovac Plus booster application in primed individuals with BBIBP-CorV or ChAdOx1-S successfully increased specific antibodies' levels without any serious adverse events. This vaccine could be administrated in the heterologous regimen to effectively boost humoral immune responses.

Crimean-Congo Hemorrhagic Fever Virus Kinetics in Serum, Saliva, and Urine, Iran, 2018.

Little is known about using noninvasive samples for diagnosing Crimean-Congo hemorrhagic fever (CCHF). We investigated detection of CCHF virus in serum, saliva, and urine samples. Our results indicate that serum is the best sample type for CCHF diagnosis; saliva can be used for noninvasive sampling.

Persistence of IgG and neutralizing antibodies in Crimean-Congo hemorrhagic fever survivors.

The World Health Organization classified Crimean-Congo hemorrhagic fever (CCHF) as a high-priority infectious disease and emphasized the performance of research studies and product development against it. Little information is available about the immune response due to natural CCHF virus (CCHFV) infection in humans. Here, we investigated the persistence of IgG and neutralizing antibodies in serum samples collected from 61 Iranian CCHF survivors with various time points after recovery (<12, 12-60, and >60 months after disease). The ELISA results showed IgG seropositivity in all samples while a pseudotyped based neutralization assay findings revealed the presence of neutralizing antibody in 29 samples (46.77%). For both IgG and neutralizing antibodies, a decreasing trend of titer was observed with the increase in the time after recovery. Not only the mean titer of IgG (772.80 U/mL) was higher than mean neutralizing antibody (25.64) but also the IgG persistence was longer. In conclusion, our findings provide valuable information about the long-term persistence of humoral immune response in CCHF survivors indicating that IgG antibody can be detected at least 8 years after recovery and low titers of neutralizing antibody can be detected in CCHF survivors.

Clinical and genomic evaluations of a persistent fatal SARS-CoV-2 infection in a goods syndrome patient: a case report.

The coronavirus disease of 2019 (COVID-19) resulted from an infection by severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) which is the main cause of acute respiratory distress syndrome (ARDS) in global population from 2019 on. It may contribute to higher rate of death among the patients with immunodeficiency based on recent reports. In addition, Good syndrome (GS) as a result of thymoma removal might cause in some long-lasting microbial infections. We described clinical aspects and viral mutations on a case of GS suffering from COVID-19. A 46-year-old man with fever, common respiratory disease symptoms and positive COVID-19 polymerase chain reaction (PCR) test, with the history of thymoma removal surgery was admitted to Masih Daneshvari Hospital, Tehran, Iran. Lung radiographs and oxygen saturation measurement disclosed considerable implication resulted in application of several anti-microbial medication. The delta variant (B.1.617.2 (21 J Clade)) was the strain isolated from the patient by sequencing methods done by the COVID-19 National Reference Laboratory (CNRL), Pasteur Institute of Iran, while the dominant strain circulated mostly among population was Omicron (B.1.1.529) at the time of sampling. Unfortunately, the patient had passed away a month later by sudden respiratory failure progressed in refractory septic shock. Despite the fact that opportunistic infections may lead the GS patients to a major health problematic condition, unusual persistent of infections such as non-dominant variant of SARS-Cov-2 could be observed through the disease timeline. Therefore, a fully screening of thymoma plus intra-host evolution monitoring of SARS-CoV-2 is highly recommended in immunocompromised patients.

The nuts and bolts of recombination in the generation of SARS-CoV-2 variants; from XA to XBB.

Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), new variants with enhanced transmissibility and pathogenicity have surfaced. The World Health Organization has designated five such variants-Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.1.529)-as variants of concern. Each variant exhibits distinct characteristics, with many displaying a combination of point mutations and insertions/deletions (indels). These genetic alterations, including mutations, recombinations, and rearrangements, contribute to the emergence of new strains that may exhibit modified phenotypes. However, identifying recombinant forms can be challenging due to their resemblance to other lineages. It is critical to monitor the evolution of new recombinant variants, particularly in light of the potential for vaccine-resistant strains and their accelerated propagation. Recombination has played a pivotal role in the development of certain SARS-CoV-2 variants, such as XA, XD, XF, XE, and XBB, among others. This report delves into the significance of recombination in the evolution of SARS-CoV-2 variants, especially Omicron sublineages, underscoring the necessity for continuous surveillance of the SARS-CoV-2 genome to identify newly emerged recombinant variants.

Epidemiological surveillance of respiratory viral infections in SARS-CoV-2-negative samples during COVID-19 pandemic in Iran.

BACKGROUND: To improve the patient care, public health surveillance, and infection control, it is crucial to identify the presence and frequency of the common respiratory infections in individuals with COVID-19 symptoms but tested negative for SARS-CoV-2. This study aimed to shed light on this during the COVID-19 pandemic in Iran. METHODS: In this cross-sectional study, a total of 1,002 patients with acute respiratory infection who had negative SARS-CoV-2 test results and referred to Valfajr Health Center, the National Collaborating Laboratory of Influenza and COVID-19 National Reference Laboratory at Pasteur Institute of Iran were recruited between January 2020 and January 2022. Nasopharyngeal and oropharyngeal swab samples were collected to detect 17 common respiratory viruses via TaqMan one-step real-time multiplex PCR. Demographic and clinical data of the participants were obtained from their electronic medical records. RESULTS: In total, 218 samples (21.8%) were tested positive for at least one respiratory virus infection. Most of the common investigated respiratory viruses belonged to the years 2020 and 2022. The number of investigated patients in 2021 was few, which highlights the impact of health measures following the COVID-19 pandemic in Iran. Influenza A was the most common virus (5.8%), while adenovirus had the lowest prevalence (0.1%). Although the rate of respiratory virus infection was higher in men (24%) compared to women (19.3%), this difference was not statistically significant (P = 0.069). The prevalence of respiratory viruses had an inverse association with increasing age, with the highest rate (55.6%) observed in the age group below 2 years and the lowest rate (12.7%) in those above 65 years. CONCLUSION: Our findings underscore the significance of adopting a comprehensive approach to respiratory infections detection and management. These results can be employed for the development of syndromic surveillance systems and implementation of the effective infection control measures. Furthermore, the results contribute to better understanding of the dynamics of respiratory viruses, both during pandemic periods and in non-pandemic contexts.

Comparison of a Multiplex Real-Time PCR Technique with Oxford Nanopore Technologies Next-Generation Sequencing for Identification of SARS-CoV-2 Variants of Concern.

INTRODUCTION: The rapid emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and their potential to endangering the global health has increased the demand for a fast-tracking method in comparison to the next-generation sequencing (NGS) as a gold standard assay, particularly in developing countries. This study was designed to evaluate the performance of a commercial multiplex real-time PCR technique (GA SARS-CoV-2 OneStep RT-PCR Kit, Iran) for identification of SARS-CoV-2 variants of concern (VOCs) compared to the Oxford Nanopore NGS assay. METHODS: A total of 238 SARS-CoV-2-positive respiratory samples from different waves of COVID-19 in Iran were randomly selected in this study. To determine the SARS-CoV-2 VOC, the samples were analyzed via the commercial triple target assay, GA SARS-CoV-2 OneStep RT-PCR Kit, and NGS as well. RESULTS: The results revealed good concordance between GA SARS-CoV-2 OneStep RT-PCR Kit and NGS for identification of SARS-CoV-2 VOCs. GA SARS-CoV-2 OneStep RT-PCR Kit identified Wuhan, Alpha, and Delta variants with 100% relative sensitivity and specificity. Regarding Omicron subvariants of BA.1, BA.2, and BA.4/5, the relative sensitivity of 100%, 100%, and 81.5% and the relative specificity of 95.3%, 93.5%, and 100% were observed. CONCLUSION: Overall, GA SARS-CoV-2 OneStep RT-PCR Kit can be used as a rapid and cost-effective alternative to NGS for identification of SARS-CoV-2 VOCs.

Designing vaccine candidates against dengue virus by in silico studies on structural and nonstructural domains.

One-third of the world's population is at risk of Dengue infection. Envelope domain 3 (EDIII) and nonstructural protein1 (NS1) proteins as the potent antigenicity regions for humoral immunity in addition to the bc loop region as a completely conserved region have been used for designing protective vaccines. We aimed to design vaccine candidates according to the bc loop, EDIII, and NS1 regions of Dengue serotype2 to be used as vaccine candidates for all serotypes of Dengue virus especially serotype 2. Firstly the bc loop region with EDII fragments at both ends as well as EDIII and NS1 regions were used which were linked with the GGGGS linker to the bc loop region. In two other strategies, the bc loop with EDII and NS1 fragments at both ends was used to increase its structural stability. Tertiary structure prediction and validation of vaccine constructs indicated that all vaccine constructs were modeled with high quality and stable structure during molecular dynamics simulation. B cell epitope mapping by Bepipred and ElliPro methods confirmed the existence of high potent epitopes in the bc loop, EDIII, and NS1 regions in both linear and conformational B cell epitopes. Furthermore, molecular docking for the bc loop region demonstrated that all designed vaccines have a higher affinity to interact with 1C19 monoclonal antibody than only the bc loop region or bc loop epitope in the protein EII. Our data of in silico studies indicated that the designed vaccines could effectively induce humoral immunity against four dengue serotypes.

The ins and outs of SARS-CoV-2 variants of concern (VOCs).

SARS-CoV-2, a newly emerging coronavirus that caused the COVID-19 epidemic, has been spreading quickly throughout the world. Despite immunization and some fairly effective therapeutic regimens, SARS-CoV-2 has been ravaging patients, health workers, and the economy. SARS-CoV-2 mutates and evolves to adapt to its host as a result of extreme selection pressure. As a consequence, new SARS-CoV-2 variants have emerged, some of which are classified as variants of concern (VOC) because they exhibit greater transmissibility, cause more-severe disease, are better able to escape immunity, or cause higher mortality than the original Wuhan strain. Here, we introduce these VOCs and review their characteristics, such as transmissibility, immune escape, mortality risk, and diagnostics.

Severe acute respiratory syndrome-coronavirus-2 spike (S) protein based vaccine candidates: State of the art and future prospects.

Coronavirus disease 2019 (Covid-19) is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) which is responsible for a global pandemic that started in late 2019 in Wuhan, China. To prevent the worldwide spread of this highly pathogenic virus, development of an effective and safe vaccine is urgently needed. The SARS-CoV-2 and SARS-CoV share a high degree of genetic and pathologic identity and share safety and immune-enhancement concerns regarding vaccine development. Prior animal studies with first generation (whole virus-based) preparations of SARS-CoV vaccines (inactivated and attenuated vaccine modalities) indicated the possibility of increased infectivity or eosinophilic infiltration by immunization. Therefore, development of second and third generation safer vaccines (by using modern vaccine platforms) is actively sought for this viral infection. The spike (S) protein of SARS-CoVs is the main determinant of cell entry and tropism and is responsible for facilitating zoonosis into humans and sustained person-to-person transmission. Furthermore, 'S' protein contains multiple neutralizing epitopes that play an essential role in the induction of neutralizing antibodies (nAbs) and protective immunity. Moreover, T-cell responses against the SARS-CoV-2 'S' protein have also been characterized that correlate to the IgG and IgA antibody titres in Covid-19 patients. Thus, S protein is an obvious candidate antigen for inclusion into vaccine platforms against SARS-CoV-2 viral infection. This manuscript reviews different characteristics of S protein, its potency and 'state of the art' of the vaccine development strategies and platforms using this antigen, for construction of a safe and effective SARS-CoV-2 vaccine.

Predictive Value Alteration of Laboratory Routine and Ferritin/Transferrin Ratio in Monitoring of COVID-19 Patients.

BACKGROUND: Inflammatory processes activated by rapid viral replication of SARS-CoV-2 can play a key role in the pathogenesis of multiple organ damage and be responsible for the COVID-19 patients' dramatic outcomes and common abnormal laboratory findings. The aim of this study was to assess the correlation between various laboratory biomarkers, ferritin/transferrin ratio (FTR) and receiver operating characteristic (ROC) analysis in monitoring COVID-19 patients. METHODS: This observational study was conducted in three groups: healthy participants, non COVID-19 patients with COVID-19-like clinical signs, and COVID-19 patients (severe and non-severe). Biochemical (CRP, ferritin, transferrin and albumin) and hematological (WBC, lymphocytes) parameters were assessed by automated methods. Moreover, FTR and NLR markers were calculated in the three groups mentioned. Statistical analyses were done using R (version 4.1.0). ROC curve was used to validate the predictive value of parameters. RESULTS: The COVID-19 positive group had significantly higher NEU, CRP, ferritin, FTR values, while it's WBC, absolute counts of lymphocytes and albumin were significantly lower compared to the non-COVID-19 patients (p < 0.001). Serum ferritin and FTR level of the severe group was significantly higher than that of the non-severe group (p = 0.006 and (p = 0.011, respectively). The strongest correlation in all subjects showed between lymphocytopenia and increased NEU (r = -0.99, p < 0.001). The AUC values of WBC (0.95), lymphocytes (0.89), NEU (0.88), and NLR (0.88) were higher than CRP (0.64) or Ferritin (0.81). CONCLUSIONS: We recommend using FTR, WBC, and NLR changes as simple, useful, and inexpensive indicators in early detection of COVID-19 patients.

SARS-CoV-2 re-infection rate in Iranian COVID-19 cases within one-year follow-up.

Since the COVID-19 pandemic initiation, the possibility of re-infection has been unclearly present. Although herd immunity has a potential reliance through natural infection, human corona viruses has the ability to subvert immunity and re-infection happens for seasonal corona viruses. Currently, the frequency of SARS-CoV-2 re-infection incidence is not exactly defined. In this study we aimed at determination of SARS-CoV-2 re-infection rate in Iranian population. In a total of 5696 COVID-19 suspicious individuals, RT-PCR was applied to diagnose the infection. The confirmed patients were followed for 12 months and serology tests were applied to measure the specific antibodies. Among 1492 confirmed COVID-19 cases, five individuals experienced the subsequent infection. The re-infection/reactivation incidence rate was totally 0.33% after one year of follow-up. The interval ranged from 63 to 156 days. All the cases had viral mutations in the second episode of the infection. All of them were symptomatic cases with moderate severity. The estimated rate of SARS-CoV-2 in Persian population is therefore rare and natural infection seems to induce good protection against re-infection which clarifies that mass vaccination can hugely affect the society.

Clinical characteristics of SARS-CoV-2 by re-infection vs. reactivation: a case series from Iran.

COVID-19 immunity in infected individuals may not be persistent. The specific response wanes in patients who have recovered from this infection. Nevertheless, it has not been fully understood whether true re-infection occurs or the viral reactivation. In this study, we investigated three COVID-19 patients who represented the symptoms after recovery. Chest CT scan was applied to assess the patients along with the viral samples from oropharyngeal/nasopharyngeal which were subjected to RT-PCR. The viral genome sequencing was applied where possible to distinguish possible re-infection or latent reactivation. Moreover, COVID-19-specific antibodies available data were evaluated in each incidence. The second episode of SARS-CoV-2 infection was different among the investigated subjects who experienced an interval between positive PCR tests ranged between 63 and 156 days. The disease presentation was less or more severe in the second infection. All cases were found IgG positive in the re-infection phase. The sequencing of SARS-CoV-2 sample obtained from two cases revealed a D614G mutation of S gene from the second isolated sample strengthens the case for the re-infection. The possibility of re-infection and reactivation could have significant effect on clinical implications and also vaccination. Our data supports clear warning of SARS-CoV-2 continuous circulation potency among the populations in spite of herd immunity either with natural infection or vaccination. This issue is critical in term of the patients, clinical investigate, and viral transmission.

The Inclusive Review on SARS-CoV-2 Biology, Epidemiology, Diagnosis, and Potential Management Options.

A novel coronavirus member was reported in Wuhan City, Hubei Province, China, at the end of the year 2019. Initially, the infection spread locally, affecting the Wuhan people, and then expanded rapidly throughout the world. On 11 March 2020, the World Health Organization (WHO) proclaimed it a global pandemic. The virus is a new strain most closely related to a bat coronavirus (RaTG13) which was not previously discovered in humans and is now formally known as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Coronavirus disease 2019 (COVID-19) is the disease syndrome that the SARS-CoV-2 virus triggers. It is suggested that SARS-CoV-2 can be transmitted through aerosols, direct/indirect contact, and also during medical procedures and specimen handling. The infection is characterized by isolated flu-like symptoms, but there may be specific signs of fever, fatigue, cough, and shortness of breath, as well as the loss of smell and breathing difficulty. Within this report, we tried to review the most current scientific literature published by January 2021 on various aspects of the outbreak, including virus structure, pathogenesis, clinical presentation, epidemiology, diagnostic approaches, potential therapeutics and vaccines, and prospects. We hope this article makes a beneficial impact on public education to better deal with the SARS-CoV-2 crisis and push a step forward in the near term towards its prevention and control.

Taguchi array optimization of the reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for sensitive and rapid detection of dengue virus serotype 2.

OBJECTIVES: Serotype 2 of dengue virus (DENV-2) is the most prevalent cause of dengue fevers. In this study, the C-prM gene was used for specific detection of DENV-2 by RT-LAMP assay. The RT-LAMP assay was optimized using the Taguchi design of experiments. RESULTS: The efficiency of the assay in such optimal conditions resulted in 100% sensitivity, 100% specificity, and 100% overall accuracy for detection of 4 copies/µL of the genome of DENV-2. In addition, the detection of 2 copies/µL of the genome of DENV-2 was feasible, although the sensitivity was 50%. Considering the importance of the specific detection of the dengue virus serotypes, the cost-effective RT-LAMP approach can be used for rapid, specific, and sensitive detection of DENV-2. CONCLUSION: RT-LAMP, as a cost-effective method, was optimized using Taguchi array approach for specific and rapid detection of DENV-2. Such methods can facilitate the diagnosis procedure in remote regions.

Serosurvey of Crimean-Congo hemorrhagic fever virus in livestock, Kohgiluyeh and Boyer-Ahmad, Iran, 2017.

BACKGROUND & OBJECTIVES: Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonosis with up to 50% mortality rate in humans. In addition to the role of animals in the transmission of the virus and spread of infected ticks through livestock trade, they can be employed as sentinel hosts for monitoring the infection. Iran is one of the endemic counties for CCHF and the disease has been documented in all provinces. However, in some provinces such as Kohgiluyeh and Boyer-Ahmad, the rate of the disease has been dramatically low. Therefore, this serosurvey was designed to investigate CCHF virus (CCHFV) seroprevalence among livestock in different parts of Kohgiluyeh and Boyer-Ahmad Province. METHODS: This study was conducted in 2017, in which, blood samples were collected from 501 sheep and goats from eight different cities of Kohgiluyeh and Boyer-Ahmad Province. CCHFV IgG antibodies were detected in livestock serum samples by specific ELISA assays for detection of ovine and caprine antibodies. RESULTS: In total, four sheep serum of out of 501 (0.8%) livestock samples (3 from Gachsaran and 1 from Dena) had CCHFV IgG antibodies. No significant association was found between CCHFV seropositivity and sex or age of animals (P>0.05). INTERPRETATION & CONCLUSION: Our findings suggest a minor CCHFV circulation in Kohgiluyeh and Boyer-Ahmad Province, Iran. However, due to the notion that outbreaks of tick-borne infections is hard to predict; steady and comprehensive monitoring programs especially in ticks and animals would be critical for understanding the circulation on the pathogen in a region.

Efficient production of a lentiviral system for displaying Crimean-Congo hemorrhagic fever virus glycoproteins reveals a broad range of cellular susceptibility and neutralization ability.

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease with a mortality rate of up to 50% in humans. To avoid safety concerns associated with the use of live virus in virus neutralization assays and to detect human serum neutralizing antibodies, we prepared lentiviral particles containing the CCHF glycoprotein (lenti-CCHFV-GP). Incorporation of the GP into the lentiviral particle was confirmed by electron microscopy and Western blotting. Lenti-CCHFV-GP was found to be able to infect a wide range of cell lines, including BHK-21, HeLa, HepG2, and AsPC-1 cells. In addition, lenti-CCHFV-GP was successfully used as an alternative to CCHFV for the detection of neutralizing antibodies. Sera collected from CCHF survivors neutralized lenti-CCHFV-GP particles in a dose-dependent manner. Our results suggest that the lenti-CCHFV-GP pseudovirus can be used as a safe tool for neutralization assays in low-containment laboratories.

Hantavirus infection in Iranian patients suspected to viral hemorrhagic fever.

BACKGROUND: Hantaviruses are a group of emerging pathogens causing hemorrhagic fever with renal syndrome and Hantavirus cardiopulmonary syndrome in human. This study was conducted to investigate Hantavirus infection among Iranian viral hemorrhagic fever suspected patients. METHODS: From April 2014 to June 2016, 113 cases from 25 different provinces of Iran were analyzed for Hantavirus infection by IgM/IgG ELISA and pan-Hantavirus RT-PCR tests. RESULTS: Although, viral genome was detected in none of the subjects, IgM and IgG antibodies were detected in 19 and 4 cases, respectively. Differentiation of the anti-Hantavirus antibodies according to virus species by EUROLINE Anti-Hantavirus Profile Kit revealed three Puumala virus IgM positive, one Hantaan virus IgM positive, one Hantaan virus IgM borderline, and two Puumala virus IgG borderline cases. CONCLUSIONS: This study demonstrates the circulation of Hantaviruses in Iran and calls for further investigations of these life-threatening viruses in the country.

Imported cases of Chikungunya virus in Iran.

BACKGROUND: Chikungunya virus (CHIKV) is a widespread mosquito-borne virus representing a serious challenge to public health. The largest outbreak in the Middle-East was recorded in 2016-2017 in Pakistan. Sistan and Baluchistan Province of Iran shares a wide border with Pakistan; accordingly, introduction of CHIKV from Pakistan to Iran seems to be probable. The current study is aimed at investigating CHIKV infection in Sistan and Baluchistan Province. METHODS: Between April 2017 and June 2018, a total of 159 serum samples of CHIK suspected cases from 10 cities of Sistan and Baluchistan Province were tested by molecular and serological assays. Samples obtained up to 4 days after onset of illness were tested by real time PCR (n = 8). Samples collected 5-10 days after disease onset were subjected to ELISA, as well as real time PCR tests (n = 72). Samples obtained after the 10th day of disease onset were tested by only ELISA (n = 79). Phylogenetic analysis of real time PCR positive samples was carried out by sequencing of a 1014-bp region of Envelope 1 gene (E1 gene). Chi-square and independent t tests were used to evaluate the association between variables and CHIKV infection. RESULTS: In total, 40 (25.1%) out of 159 samples tested positive either by real time PCR or ELISA tests.Out of 151 samples serologically analyzed, 19 (12.6%) and 28 (18.6%) cases were positive for anti-CHIKV IgM and anti-CHIKV IgG antibodies, respectively. Of 80 samples tested by real time PCR, CHIKV RNA was detected in 11 (13.7%) sera, all of them had recent travel history to Pakistan. Additionally, phylogenetic analysis of 5 samples indicated their similarity with recent isolates of Pakistan outbreak 2016-2017 belonging to Indian Ocean sub-lineage of ECSA genotype. A significant correlation between abroad travel history and CHIKV infection was observed (P < 0.001). The most common clinical symptoms included fever, arthralgia/arthritis, myalgia, headache, and chill. CONCLUSIONS: These results present substantial evidence of CHIKV introduction to Iran from Pakistan and emphasize the need for the enhancement of surveillance system and preventive measures.

Seroprevalence of West Nile virus in Khuzestan province, southwestern Iran, 2016-2017.

BACKGROUND & OBJECTIVES: West Nile virus (WNV) is a neurotropic Flavivirus transmitted to humans through mosquito bites. As there is no specific antiviral treatment or approved vaccine against WNV, control and prevention of the infection is the best strategy to reduce the burden of WNV-related diseases. The circulation of WNV has been indicated in several regions of Iran including the Khuzestan province. Considering the complex ecology of WNV, the latest data are necessary for the implementation of preventive measures. Therefore, the present study was designed to provide updated information on the seroepidemiology of WNV in Khuzestan province. METHODS: A total of 408 sera were taken from volunteers living in Khuzestan. The presence of specific immunoglobulin G (IgG) antibody against WNV was tested by the enzyme-linked immunosorbent assay (ELISA) method. All the data and participants' demographic information were analyzed by SPSS and Esri's ArcMap GIS software programs. RESULTS: Anti-WNV IgG antibody was detected in 97 (23.8%) out of the 408 tested sera. The highest seropositivity rate was observed in cases aged between 20-29 yr and the lowest seropositivity rate was seen in those <19 yr of age (p = 0.001). There was no statistically significant association between WNV infection and gender, occupation, and educational level. The majority of positive cases were from the city of Ahvaz (47 cases, 48.4%) and Andimeshk (32 cases, 33%). INTERPRETATION & CONCLUSION: This study supports the earlier findings suggesting the circulation of WNV in Khuzestan province. Therefore, the implementation of an integrated surveillance system and training of health care workers and general population regarding the infection would be valuable to reduce the burden of possible outbreaks.