Seroprevalence of dengue fever and the associated sociodemographic, clinical, and environmental factors in Makkah, Madinah, Jeddah, and Jizan, Kingdom of Saudi Arabia.

This study aimed to estimate the seroprevalence of anti-dengue IgG antibodies in Makkah, Al Madinah, Jeddah, and Jizan; and to identify the associated demographic, clinical, and environmental independent risk factors. A community-based household serosurvey conducted between September 20, 2016 and January 31, 2017. A multi-stage stratified cluster sampling was used to select 6596 participants from Makkah, Madinah, Jeddah, and Jizan. Blood samples were drawn from all participants to detect anti-dengue IgG antibodies. A semi-structured questionnaire was used to collect information on demographic, clinical, and environmental data. Multivariate logistic regression was carried out to identify independent risk factors of dengue seropositivity. The dengue seroprevalence (95% confidence intervalI) was 26.7% (25.6%, 27.8%), with the highest (33.6%) and lowest (14.8%) rates in Jizan and Madinah, respectively, and reaching 50% or more in several districts of the four cities. Demographic predictors of seroprevalence included: dwelling in Makkah (odds ratio [OR] = 2.19, p < 0.001) or Jizan (OR = 2.17, p < 0.001); older age (OR = 3.91, p < 0.001 for age>30 years); housing type (OR = 1.84 and 1.82, p < 0.001 for popular and social houses, respectively); and number of household occupants (OR = 0.86 and 0.71 for 6-10 [p = 0.042] and 11-20 [p = 0.002] occupants, respectively). Environmental predictors included the absence of pest control works in residency area (OR = 1.39, p = 0.002), presence of mosquitoes in the home (OR = 1.39, p = 0.001), and absence of awareness campaigns (OR = 1.97, p < 0.001). One in four inhabitants of the Western region of Saudi Arabia was seropositive for the dengue virus. Implementation of behavior-based educational programs is recommended, involving the population in the identification and eradication of vector sources and promoting appropriate behaviors that prevent the spread.

An observational, laboratory-based study of outbreaks of middle East respiratory syndrome coronavirus in Jeddah and Riyadh, kingdom of Saudi Arabia, 2014.

BACKGROUND: In spring 2014, a sudden rise in the number of notified Middle East respiratory syndrome coronavirus (MERS-CoV) infections occurred across Saudi Arabia with a focus in Jeddah. Hypotheses to explain the outbreak pattern include increased surveillance, increased zoonotic transmission, nosocomial transmission, and changes in viral transmissibility, as well as diagnostic laboratory artifacts. METHODS: Diagnostic results from Jeddah Regional Laboratory were analyzed. Viruses from the Jeddah outbreak and viruses occurring during the same time in Riyadh, Al-Kharj, and Madinah were fully or partially sequenced. A set of 4 single-nucleotide polymorphisms distinctive to the Jeddah outbreak were determined from additional viruses. Viruses from Riyadh and Jeddah were isolated and studied in cell culture. RESULTS: Up to 481 samples were received per day for reverse transcription polymerase chain reaction (RT-PCR) testing. A laboratory proficiency assessment suggested positive and negative results to be reliable. Forty-nine percent of 168 positive-testing samples during the Jeddah outbreak stemmed from King Fahd Hospital. All viruses from Jeddah were monophyletic and similar, whereas viruses from Riyadh were paraphyletic and diverse. A hospital-associated transmission cluster, to which cases in Indiana (United States) and the Netherlands belonged, was discovered in Riyadh. One Jeddah-type virus was found in Riyadh, with matching travel history to Jeddah. Virus isolates representing outbreaks in Jeddah and Riyadh were not different from MERS-CoV EMC/2012 in replication, escape of interferon response, or serum neutralization. CONCLUSIONS: Virus shedding and virus functions did not change significantly during the outbreak in Jeddah. These results suggest the outbreaks to have been caused by biologically unchanged viruses in connection with nosocomial transmission.

Respiratory tract samples, viral load, and genome fraction yield in patients with Middle East respiratory syndrome.

BACKGROUND: Analysis of clinical samples from patients with new viral infections is critical to confirm the diagnosis, to specify the viral load, and to sequence data necessary for characterizing the viral kinetics, transmission, and evolution. We analyzed samples from 112 patients infected with the recently discovered Middle East respiratory syndrome coronavirus (MERS-CoV). METHODS: Respiratory tract samples from cases of MERS-CoV infection confirmed by polymerase chain reaction (PCR) were investigated to determine the MERS-CoV load and fraction of the MERS-CoV genome. These values were analyzed to determine associations with clinical sample type. RESULTS: Samples from 112 individuals in which MERS-CoV was detected by PCR were analyzed, of which 13 were sputum samples, 64 were nasopharyngeal swab specimens, 30 were tracheal aspirates, and 3 were bronchoalveolar lavage specimens; 2 samples were of unknown origin. Tracheal aspirates yielded significantly higher MERS-CoV loads, compared with nasopharyngeal swab specimens (P = .005) and sputum specimens (P = .0001). Tracheal aspirates had viral loads similar to those in bronchoalveolar lavage samples (P = .3079). Bronchoalveolar lavage samples and tracheal aspirates had significantly higher genome fraction than nasopharyngeal swab specimens (P = .0095 and P = .0002, respectively) and sputum samples (P = .0009 and P = .0001, respectively). The genome yield from tracheal aspirates and bronchoalveolar lavage samples were similar (P = .1174). CONCLUSIONS: Lower respiratory tract samples yield significantly higher MERS-CoV loads and genome fractions than upper respiratory tract samples.

The diagnostic challenge of pandemic H1N1 2009 virus in a dengue-endemic region: a case report of combined infection in Jeddah, Kingdom of Saudi Arabia.

It is difficult to distinguish dengue fever from other febrile illnesses in a dengue-endemic area. This issue was compounded during the H1N1 2009 pandemic of influenza, which also presents as a febrile illness. This first laboratory-confirmed case of co-infection with dengue and influenza A H1N1 2009 strain in Jeddah, Saudi Arabia, highlights the importance of considering co-infections because not only is influenza an ongoing concern in Jeddah, but several viral hemorrhagic fever viruses circulate in this region.

Detection of respiratory viruses among pilgrims in Saudi Arabia during the time of a declared influenza A(H1N1) pandemic.

BACKGROUND: The objectives of this study were to determine whether pilgrim attendance at the Hajj was associated with an increased risk of acquiring influenza, and other respiratory viruses, and to evaluate the compliance of pilgrims with influenza vaccination and other recommended preventive measures. METHODS: A cross-sectional survey was conducted among pilgrims as they arrived at the King Abdulaziz International Airport in Jeddah for the 2009 Hajj and as they departed from the same airport during the week after the Hajj. Nasopharyngeal and throat swabs were tested for 18 respiratory virus types and subtypes using the xTAG Respiratory Viral Panel FAST assay. RESULTS: A total of 519 arriving pilgrims and 2,699 departing pilgrims were examined. Their mean age was 49 years and 58% were male. In all, 30% of pilgrims stated that they had received pandemic influenza A(H1N1) vaccine before leaving for the Hajj and 35% of arriving pilgrims reported wearing a face mask. Only 50% of arriving pilgrims were aware of preventive measures such as hand hygiene and wearing a mask. The prevalence of any respiratory-virus infection was 14.5% (12.5% among arriving pilgrims and 14.8% among departing pilgrims). The main viruses detected (both groups combined) were rhinovirus-enterovirus (N = 414, 12.9%), coronaviruses (N = 27, 0.8%), respiratory syncytial virus (N = 8, 0.2%), and influenza A virus (N = 8, 0.2%) including pandemic influenza A(H1N1) (N = 3, 0.1%). The prevalence of pandemic influenza A(H1N1) was 0.2% (N = 1) among arriving pilgrims and 0.1% (N = 2) among departing pilgrims. The prevalence of any respiratory virus infection was lower among those who said they received H1N1 vaccine compared to those who said they did not receive it (11.8% vs 15.6%, respectively, p = 0.009). CONCLUSION: We found very low pandemic influenza A(H1N1) prevalence among arriving pilgrims and no evidence that amplification of transmission had occurred among departing pilgrims.

The prevalance of respiratory viruses among healthcare workers serving pilgrims in Makkah during the 2009 influenza A (H1N1) pandemic.

Despite the high risk of acquiring respiratory infections, healthcare workers who treat pilgrims at Hajj have not been studied in previous research on respiratory diseases during Hajj. The objective of this study was to determine the prevalence of different respiratory viruses among healthcare workers who treated pilgrims during Hajj 2009, the year of the influenza A H1N1 pandemic. A cross-sectional study was performed just before and after Hajj (25-29 November, 2009). Nasal and throat swabs were tested for 18 respiratory virus types and subtypes. A total of 184 healthcare workers were examined. Most were men (85%) with an average age of 41 years. Before the Hajj, rates of seasonal influenza vaccination were higher (51%) than rates of pandemic influenza A H1N1 vaccination (22%). After the Hajj, participants reported high rates of maintaining hand hygiene (98%), cough etiquette (89%), and wearing a face mask (90%). Among all the viruses tested, only two were detected: rhinovirus was detected in 12.6% and Coronavirus 229E in 0.6%. Rhinovirus was detected in 21% of those who had respiratory symptoms during Hajj. Influenza A (including H1N1), influenza B. respiratory syncytial virus, other coronaviruses, parainfluenza viruses, human metapneumovirus, adenovirus, and human bocavirus were not detected. The finding of high rates of rhinovirus infection corresponds to their frequent occurrence in adults. None of the participants had influenza A H1N1 2009, possibly because it was also infrequent among the 2009 pilgrims.