Infectious Disorders - Drug Targets (Formerly Current Drug Targets - Infectious Disorders) - Volume 14, Issue 2, 2014

Encephalitis is caused by inflammation and/or infection of the brain. It is a important condition in Asian children in whom it is most frequently caused by Japanese encephalitis virus, associated with a considerable burden of disease. Other common causes in Asia include: enteroviruses (especially enterovirus 71), dengue, influenza, the herpesviruses, measles, mumps and rubella viruses. Rabies continues to result in high mortality mostly in Asian children, which represents missed opportunities for prevention. Asia has also seen a number of emerging viral encephalitides including: Nipah, chikungunya, Chandipura and Me Tri viruses. We review the aetiology, epidemiology and outcome of encephalitis in Asian children and identify priorities for public health practice and research.

Background: This study examines national childhood HSV mortality data in Australia from 1999-2011. This information is important to better understand the disease burden of HSV in early life and to formulate public health interventions. Methods: Retrospective analysis of Australian Bureau of Statistics (ABS) national mortality data from 1999- 2011 in children aged <15 years who died with specific ICD-10 codes for HSV infection listed as an underlying or contributing cause. Results: Twenty nine HSV-associated deaths in children aged <15 years from 1999-2011 were identified (0.05 per 100,000 children; 95% CI 0.04-0.06), 16 in the first month of life (0.45 per 100,000 live births; 95% CI 0.23- 0.67). Among those, 20 were males and 9 were females (p=0.04). The majority of deaths (69%) occurred in infants aged <12 months and most in infants aged <1 month (55%). HSV-associated death in infants aged < 1 month of age accounted for 0.15% of all neonatal deaths for 1999-2011 in Australia. A downward trend in HSV-associated neonatal mortality was observed between 1999 and 2011 (p=0.52). During the study period, mortality from HSV infections in Australian children resulted in an estimated 2,275 age-adjusted years of potential life lost. Conclusions: This data confirms reported findings from active surveillance of a downward trend in mortality rate from HSV infection in infants aged < 1 month in Australia over this period. Ongoing surveillance is required to confirm this observation.

Hepatitis C virus (HCV) infection among injecting drug users (IDUs) is a major public health concern. It is important to know the current burden of HCV infection among IDUs for targeted public health interventions in this high risk population. We systematically reviewed the published literature on prevalence of HCV infections among IDUs between January 1989 and April 2014. Sixty studies met the inclusion criteria for the review and subsequent analysis. Among the selected studies 26,311 IDUs were assessed for HCV infection of which 16,231 were positive, giving an overall prevalence of 61.7% (95% Confidence Interval [95% CI] 61.1-62.3%). Of the selected studies, 21 were from Asia, 20 from Europe, 13 from Americas, 5 from Australia and one from Africa. Combined regional estimates of HCV prevalence among IDUs showed that Africa has the highest mean prevalence of HCV among IDUs (97.3%, 95% CI 95.5-98.4%), however, this estimate was based only on one study from Mauritius. Europe has the second highest mean prevalence (65.9%, 95% CI 64.9-66.9%) followed by Australia (56.5%, 95% CI 53.8-59.2%). Our review suggests that the prevalence of HCV among IDUs is significantly high. There are very limited data from African nations. More comprehensive understanding of HCV epidemiology among IDUs including the risk behaviours are needed for this high risk group.

Pertussis seroepidemiology and associated factors in older adults aged ≥40 years with and without acute myocardial infarction (AMI) were studied to investigate whether unrecognised pertussis may precipitate AMI. Sera were obtained from a previous case-control study investigating the role of influenza in precipitating AMIs. Baseline sera were considered pertussis toxin (PT) IgG seropositive at levels ≥5 IU/mL. Levels ≥v62.5 IU/mL were considered indicative of infection in the previous year, and recent infection was indicative at levels ≥125 IU/mL. Of the serum samples tested, 55% (122/222) were seropositive for PT IgG, 5% (11/222) had evidence of infection in the past year and 1.4% (3/222) had evidence of recent infection. Evidence of infection in the past year was found in 3.2% of those aged 65-74 years. Overall, 47.8% of 40-64 year olds and 43.2% of those aged ≥65 years were seronegative for pertussis. Serological evidence of pertussis was not associated with AMI (46/92, 50.0% cases vs. 76/130, 58.5% controls, p=0.2). After adjusting for age, AMI and self-reported pertussis and GP verified influenza vaccination, females (OR = 2.2, 95% CI = 1.1-4.1, p=0.02) were more likely to be seronegative. Just under half of participants had no detectable pertussis immunity and are therefore susceptible to infection. Our study supports the need for an adult pertussis booster to supplement current recommendations.

Studies to determine the effectiveness of facemasks in preventing influenza have been inconclusive, largely due to small sample size. The Hajj pilgrimage, where the incidence of influenza and other respiratory infections is high, provides an excellent opportunity to test the effectiveness of facemasks against syndromic and laboratory-confirmed infections. Hence, a pilot study was conducted among Australian pilgrims to assess the feasibility of such a large-scale trial in the coming years. At the 2011 Hajj, tents were randomised to ‘supervised mask use’ versus ‘no supervised mask use’. Pilgrims with ILI symptoms for ≤3 days were recruited as ‘cases’ and those who slept within 2 meters of them as ‘contacts’. Surgical facemasks were provided to cases and contacts in the ‘mask’ tents, but not in the ‘control’ tents. Pilgrims in both groups were given diaries to record their respiratory symptoms. Nasal or pharyngeal swabs were collected from the cases and contacts with ILI for point-of-care and nucleic acid tests. A total of 22 tents were randomised to ‘mask’ (n=12) or ‘control’ (n=10). There were 164 pilgrims recruited; 75 in ‘mask’ and 89 in ‘control’ group. Mask use compliance was 76% in the ‘mask’ group and 12% in the ‘control’ group. Based on developing syndromic ILI, less contacts became symptomatic in the ‘mask’ tents compared to the ‘control’ tents (31% versus 53%, p= 0.04). However, laboratory results did not show any difference between the two groups. This pilot study shows that a large trial to assess the effectiveness of facemasks use at Hajj is feasible.

The uptake of the pneumococcal vaccine is suboptimal in Australia and remains unknown among Australian Hajj pilgrims, many of whom are eligible because of age or underlying disease and at particular risk because of travel and activities at Hajj. Pneumococcal vaccination uptake was examined over three consecutive years (2011 to 2013) through anonymous self-administered cross sectional surveys among Australian pilgrims who assembled in Mina valley, Mecca, Saudi Arabia. Respectively, 158, 513 and 219 pilgrims were recruited in 2011, 2012 and 2013; their mean ages were 43.8 (SD±13), 43 (SD±13.5) and 42.6 (SD±12.3) years; males accounted for 67 (42.4%), 325 (63.4%) and 172 (78.5%). Pneumococcal vaccine uptake rates were 28.5% (45/158), 28.7% (147/513) and 14.2% (31/219); among the pilgrims with ‘at risk’ conditions the pneumococcal vaccine uptake rates were 15 (30.6%), 43 (45.3%) and 9 (29%) respectively. According to our surveys, the pneumococcal vaccine uptake among Australian pilgrims is low. Further research is needed to explore the reasons through a validated study.

Resistance to antimicrobial agents has increased for reasons relating to the use and misuse of antimicrobials in human, agriculture and aquaculture. Antimicrobial use is quite high during mass gatherings such as the Hajj pilgrimage. To reduce non-prescription use and inappropriate prescribing of antimicrobials, a more thorough understanding of their use and the motives behind why patients request, even demand, antimicrobials, fail to adhere to the prescription is important. Therefore, we conducted a knowledge, attitude and practice (KAP) survey among Australian Hajj pilgrims in Mecca during Hajj 2013 using an anonymous, self-administered questionnaire concerning antimicrobial use. Our sample consisted of 229 adult Australian subjects. Mean age was 42.4 (SD±12.7) years, 178 (77.9%) were male and 80 (34.9%) used antimicrobials during their stay in Saudi Arabia. Twenty one (26.3%) obtained these in Saudi Arabia without prescription, and about half (38, 47.5%) brought them from Australia. Of the respondents, 55.8% believed that antibiotics are effective against viruses, 53.6% thought that antibiotics are effective against common cold and flu, 78.6 % that humans themselves can become resistant to antibiotics and 75.9% knew that overuse or unnecessary use of antibiotics can cause them to lose effectiveness. This study has revealed that Hajj pilgrims have inappropriate access to antimicrobials in Saudi Arabia as well as in Australia. A large scale education campaign and tighter control on prescribing and dispensing of antimicrobials could improve the appropriate antimicrobial use among Hajj pilgrims.

People with dementia are at a greater risk of complications from respiratory infections therefore can benefit from vaccinations against influenza, pneumococcal disease and pertussis. This review aimed to evaluate the uptake and impact of vaccination in older adults with dementia against respiratory infections and identify knowledge gaps. Key databases were explored, search results were assessed, relevant studies identified, and data were synthesised and summarised. Most available data suggest that older adults with dementia are less likely to receive influenza or pneumococcal vaccine while a few studies indicate an increase in vaccination uptake but poor immunogenicity. Among dementia patients, community dwellers have a lower vaccination rate than home care residents. However, vaccinations against influenza and pneumococcal disease can benefit individuals with dementia by reducing both mortality and morbidity. Health professionals caring for patients with dementia could play a role in fostering vaccination of these individuals.

Pilgrims attending Hajj in Makkah are at high risk of suffering from trauma and foot injury as they are required to make circuits barefooted on scorching marbles around the Holy Mosque, and march between two hillocks for hours. No study has systematically described the pattern of foot wounds among them. This observational study aimed to determine the spectrum of foot injuries among diabetic and non-diabetic Hajj pilgrims and the preventive measures adopted by them. Pilgrims who attended the Hajj 2013 and sought medical care for foot wounds at mobile podiatric clinics in Mina during the peak days of Hajj were invited to participate in the study and fill out a questionnaire while they were serviced. Podiatric carers noted down the significant signs of foot injuries. Out of 197 pilgrims from 21 different countries who participated in this study, 60 (31%) were diabetic. The two most common injuries observed were blisters (34%) and erythema (25%). Both diabetic and non-diabetic Hajj pilgrims were at high risk of developing infectious wounds, however a significantly higher proportion of diabetic pilgrims had callosities. Use of appropriately fitting protective footwear, and regularity in diets and drugs are highly recommended for pilgrims’ optimum foot care. Tailored educational advice on foot hygiene before and during travel could be beneficial for Hajj pilgrims.