Tuberculous optochiasmatic arachnoiditis and optochiasmatic tuberculoma in Malaysia

@#Background & Objectives: Arachnoiditis which involves the optic chiasm and optic nervecan rarely occurs in the patients with tuberculous meningitis (TBM). The primary objective of this study was to determine the incidence, assess the clinical and neuroimaging findings, and associations, understand its pathogenesis of these patients, and determine its prognosis. Methods: The patients admitted with TBM in the neurology wards of two tertiary care hospitals from 2009 to 2017 in Kuala Lumpur, Malaysia were screened. The patients with OCA and optochiasmatic tuberculoma were included in this study. We assessed the clinical, cerebrospinal fluid (CSF), imaging findings of the study subjects and compared with other patients without OCA or optochiasmatic tuberculoma. Results: Eighty-eight patients with TBM were seen during the study period. Seven (8.0%) had OCA and one (1.1%) had optochiasmatic tuberculoma. Five out of seven (71.4%) patients with OCA were newly diagnosed cases of TBM. The other two (28.6%) had involvement while on treatment with antituberculous treatment (paradoxical manifestation). The mean age of the patients with OCA was 27.3 ± 11.7. All the OCA patients had leptomeningeal enhancement at other sites. All had hydrocephalus and cerebral infarcts on brain neuroimaging. Three (42.9%) patients had cerebral tuberculoma at sites other than suprasellar and optic chiasm areas. On univariate analysis, the presence of OCA and optochiasmatic tuberculoma was associated with raised CSF opening pressure (p=0.014), younger age (p=0.024), cerebral infarcts (p=0.018) and hydrocephalus (p= 0.046). There was no statistically significant association on logistic regression. Only one (14.3%) patient had visual impairment. Conclusion: OCA and optochiasmatic tuberculoma were seen in 9% of a cohort of Malaysian TBM patients. They were more likely to be younger, have raised CSF opening pressure, cerebral infarcts and hydrocephalus, suggesting the association with a more severe exudative disease.

Long-term socioeconomic impact of the Nipah Virus encephalitis outbreak in Bukit Pelanduk, Negeri Sembilan, Malaysia: A mixed methods approach

Background and Objective: In 1998/99, an outbreak of Nipah virus encephalitis occurred in several pig-farming communities in Malaysia. It was associated with a high mortality rate and persistent neurological defi cits among many survivors. This mixed method study aimed to examine the longterm socio-economic consequences of the illness on affected pig farmers and their families in Bukit Pelanduk, Negeri Sembilan. Methods: A quantitative cross sectional survey was conducted in 2008 on 78 former patients or their kin from 61 households (46.2% males, mean age = 48.7 years) in Bukit Pelanduk via face-to-face interviews. This was followed by qualitative in-depth interviews with 20 respondents. Results: The immediate treatment costs were not a major burden to most households. Majority of the patients (92%) required inpatient care and most obtained free care from public hospitals. Households relied mainly on savings and support provided by the public and family members during the outbreak. However, many former patients found their low educational qualifi cations prevented them from obtaining good alternative employment after their recovery. This had negatively affected their households’ living standards. As a result, there had been a renewed appreciation of the value of education for their young, and one of their main concerns was the fi nancial burden of educating their children. Conclusion: Free public health care protected most households from high medical costs. However, household living standards had dropped due to limited alternative employment opportunities. Education has been identifi ed as a key to improving the long term welfare of affected households.

Nipah virus and bats

Since the initial outbreak in Malaysia, small outbreaks of Nipah encephalitis have been reported almost annually in Bangladesh. Epidemiological studies have shown that the virus could be transmitted from bat to human and from human to human. Wildlife studies have also shown that the virus was widely distributed in at least 10 genera and 23 species of bats in a large part of Asia and Africa – a region that stretches from Australia and southern China, and from Indonesia to as far west as Ghana, a region with a total population of more than 1.4 billion people. As bats are long distant flying, gregarious animals living in large colonies which could exchange novel viruses from one species to another, it is not unexpected that the seroprevalence of Henipavirus among bat colonies are relatively high. The widespread distribution of both the Henipavirus and its hosts also means that the virus will remain an important cause of zoonotic disease.

Aetiology of viral central nervous system infection, a Malaysian study

Over 100 viruses are known to cause acute viral encephalitis in human. In order to diagnose a viral central nervous system infection, various laboratory diagnosis methods have been used. In this study, we examined 220 cerebrospinal fluid samples that were received at the Diagnostic Virology Laboratory of University Malaya Medical Centre between year 2004 to 2006, by viral isolation, pathogen specific antibody ELISA, polymerase chain reaction (PCR) and Real-Time PCR. Majority of the samples were from patients <10 years old. Out of 220 samples, 3 were positive for viral isolation, 27 for PCR (inclusive for the 3 positive for viral isolation) and 39 for pathogen specific ELISA. The total positive detection rate of this study was 30%. Herpes virus was the most important aetiologic agent, responsible for 58% of infection, followed by paramyxovirus (especially measles virus) in 26% of infection, and 14% by enterovirus. Parvovirus and flavivirus were the other common viruses. Among the herpes viruses, herpes simplex and cytomegalovirus were the most common.

Differences in epidemiologic and clinical features of Nipah virus encephalitis between the Malaysian and Bangladesh outbreaks

Since the initial outbreak of Nipah encephalitis in Malaysia in 1998, the virus has reemerged in Bangladesh and the adjacent Indian state of West Bengal since 2001. To date more than 470 patients have been affected with over 250 fatalities in total. Although the source of the virus is believed to be the Pteropus fruit bats both in Malaysia and Bangladesh, there are also significant epidemiological and clinical differences in the outbreaks occurring in these two regions. Epidemiologically, in the Bangladesh and India outbreaks, bat-to-human transmission through food and animal and human-tohuman transmissions were the predominant modes, the outbreaks were on a smaller scale and they have recurred every year except 2002 and 2006. Clinically, the mortality was higher and respiratory manifestation was more prominent in the Bangladeshi and Indian patients compared with their Malaysian counterparts, which might reflect differences in care and medical practices. There remain however, important differences in clinical manifestations which are likely to be due to some genetic variations in the virus.

Pediatric multiple sclerosis is similar to adult-onset form in Asia

Pediatric-onset multiple sclerosis is underreported because of difficulty in diagnosis and assessment. In Western series, pediatric-onset disease showed significant differences from adult-onset disease with higher female preponderance, polysymptomatic in onset, frequent systemic manifestation in relapses, higher relapse rate, but less disability, and fewer lesions in brain magnetic resonance imaging. Multiple sclerosis manifests differently in Asians, yet there was no large series of pediatric-onset multiple sclerosis reported. We found that pediatric-onset disease in Asians showed greater similarity with adult-onset disease without the reported differences in female preponderance, relapse rate, and magnetic resonance imaging findings. There were also similar proportion and clinical features in optico-spinal form, and long spinal cord lesions were common in both groups. The significant difference was less disability among the pediatric-onset group. Thus, although multiple sclerosis in Asia is different from Western countries, there is greater similarity between the pediatric-onset and adult-onset group in Asia.