Asian Journal of Research in Infectious Diseases

Acute Encephalitis Syndrome (AES) poses a great public health problem in India, occurring both in epidemics and sporadically. Although bacteria, viruses and protozoan parasites may cause encephalitis, among these; the viruses are the most common and important cause of encephalitis Japanese Encephalitis virus has been considered as leading cause of AES in India mostly occurs among children. Thus, the disease spectrum of AES seems to be much wider and may be caused by a wide variety of viruses, bacteria, protozoa, fungi, or may even be non-infectious in aetiology.  Recently, increased incidence of scrub typhus is being reported from Northern India especially eastern part of Uttar Pradesh and western part of Bihar, as reported 25% infectious aetiology in one third of the AES cases and emergence of O. tsutsugamushi infection an important causative agent of AES in India. A recent outbreak of "AES" in June 2019 was found in Muzaffarpur, Bihar India. As reported the Muzaffarpur district has initiated an investigation into the case of 672 children who were admitted with "AES" and more than 150 children have died. Case fatality rate among children due to JE was found very low now because changing aetiology of AES across various districts of Bihar.

Bacterial Meningitis (BM) is the most common serious infection of the central nervous system (brain and spinal cord). This research aims to determine the mineral composition and to evaluate the in vitro antibacterial activity of the Juice Extract of Allium Sativum, Ethanolic Extract of Allium Sativum and Aqueous Extract of Allium sativum (JEAS, EEAS and AEAS). The collected bulbs of A. sativum (600 g) were washed and air dried under shade for 2 hours and the dry scaly outer covering was peeled-off to obtain the fresh garlic cloves which were then divided into three parts of 200 g each. These three portions were crushed separately for cold extraction. The first portion was homogenized and poured into a muslin cloth to squeeze out the juice, while second and third portions were homogenized and submerged into 500 ml of 96% ethanol and 500 ml of distilled water respectively for 24 hours and both filtered after thorough shaking. The antibacterial activity of bulbs of A. sativum juice, ethanolic and aqueous (JEAS, EEAS and AEAS) extracts as folkloric medicine against clinical isolates were determined using Agar well diffusion and broth dilution method. Distilled water, concentrated nitric acid (HNO₃) and hydrochloric acid (HCl) were used to digest the extract, which was then heated in water bath at 90ºC and filtered to obtain the filtrate for the analytical studies for A. sativum nutritional composition and zeolite herbominerals. The micro-herbominerals with their proximate values observed pharmacologic of Silver, Manganese, Zinc, Iron and Selenium; which has biocidal properties as well as immune system to cushioning the challenges of the BM pathogens. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and phytochemical screening of the extracts were evaluated. The results obtained showed that the juice and ethanolic extracts were potent, inhibiting the growth of clinical isolates with zone of inhibition ranging from 14-36 mm. The extracts inhibited bacterial isolates in concentration dependant manner with MICs ranging 0.02-15 mg/ml and MBCs 0.04-5 mg/ml. Phytochemical screening of the extracts revealed the presence of alkaloids, flavonoids, anthraquinone, carbohydrates, fats and oils, steroidal ring, saponins and terpenoids. This experimental investigation has provided the scientific validation basis for the ethnomedical use of A. sativum as a remedy to treat bacterial meningitis locally as anti-infectious agent.

The purpose of the present study was to establish experimental model of toxoplasmosis in pigeons, to investigate pathogenesis and compare tissue lesions by clinical, histopathological, serological and bioassay techniques. Total of 60 unknown aged pigeons (Columba livia), 21 males and 39 females were used. They were divided into groups as oral (Group I and II) and parenteral (Group III, IV, V and VI) infection groups (Table 1). While some pigeons in Group IV showed acute infection signs such as anorexia, weight loss, pale cockscomb, bend of head and neck and partial paralyze; chronic infection signs such as anorexia, weakness, weight loss, diarrhea, difficulties in breathing, and conjunctivitis were seen in Group IV, V, and VI. In necropsy, the pigeons in Group IV had hyperemia and focal hemorrhages in the meninges and brain; the pigeons in Groups V and VI had yellowish color of the liver, the pigeons in Group V had the pale chest muscles, pericardial thickening and opaqueness. There were no macroscopic findings in pigeons in Group I and III. Histopathological examination revealed nonsuppurative meningoencephalitis and tachyzoites and bradyzoite cysts formation of T. gondii in brain tissue, lymphoid cell infiltration and necrotic focal hepatitis and nephritis in Group IV. While pigeons in Group V had nonsuppurative focal myositis, myocarditis, hepatitis, gastritis, enteritis, pneumonitis, and necrotic pancreatitis, one of them had toxoplasma bradyzoite cyst in the sinusoid in the liver. In group VI, nonsuppurative focal hepatitis, myocarditis, nephritis and necrotic pancreatitis were detected in pigeons. Bioassay tests were performed with tissue samples taken from seropositive pigeons and parasitic tachyzoites were isolated from the peritoneal fluid of the mice. Seropositivity in the oral and parenteral groups was determined by Sabin-Feldman Dye Test (SFDT) and Indirect Hemagglutination Assay (IHA). As a result; in similar studies that will be performed investigating pathogenesis of Toxoplasmosis and subclinical cases that may be overlooked, serologic tests and bioassay applications should be used together for the diagnosis of toxoplasmosis.

In 2010, 99 countries reported current malaria transmission, causing an estimated 219 million cases and 660,000 deaths, the deaths mostly in young children in Africa. In Malaysia, the country started on a Malaria Eradication Programme, MEP, in the third quarter of the past century. The MEP here is very much a success in the reason that the current rate (incidence) is very low, sporadic cases in Kelantan, Selangor, Pahang, Perak and Sarawak (mostly immigrants, imported-cases and illegal-loggers) - the disease practically eradicated except in Sabah where the disease remains endemic in the interior, although here much of monkey-malaria (P. knowlesi) spread to human. Vector-control played a big part in the MEP - the Anopheles spp breed in a wide variety of habitat depending on the species: drains and open pools of water (including seepage rain-water) had to be regularly and routinely sprayed with oil, and large unused-pools drained. But, much had been achieved by residual-spraying of homes with insecticide, and the use of mosquito-net. Residual-spraying is a big success in the reason that the Anopheles spp habitually settle (rest) on the walls after flying over to homes before starting on feeding.  Residual-spraying only requires done from time to time by a team of workers. Additional protection, achieved through community-education are: wearing fully covering light-coloured clothes in the evenings. Presently, mosquito-repellents can help - but these were unavailable in the MEP time. Chemoprophylaxis (i.e. the anti-malarial drugs) should be advised for those travelling to and through the endemic area. Armed-forces and Police-personnel were by regulation required to take chemoprophylaxis, besides such Government work. One additional very important success measure had been Active Case Detection, ACD, and Passive Case Detection (PCD) using slide-microscope followed by prompt treatment. Such ACD & PCD reduced the size of the human-reservoir from which transmission happened.

With reference my article ‘How Malaria is Practically Eradicated in Malaysia – A Reminiscence’ (AJRID, Jan 6, 2020), me seem to have left out writing on the present availability, role and impact of vaccines against malaria.

The only approved vaccine RTS,S, known by the trade name Mosquirix is launched in 2019 in a WHO-led implementation program piloting the vaccine, among children aged not more than 2 years, in three high-malaria countries in Africa. The vaccine has a relatively low efficacy at 26 – 50% - thus, the WHO do not recommend the vaccine in infants aged 6 to 12 weeks. It is given in 3 doses between 5 and 9 months of age and the fourth-dose at around 2 years old.

Said the WHO Director-General, ‘The malaria vaccine could save tens of thousands of children’s lives’.

In spite of the low-efficacy, the vaccine is safe and prevents 30% of severe malaria causing death and prevents 60% of cases of severe malaria anaemia, the most common reason children die from malaria.

The pilot-programme aim to reach around 360,000 children annually in the three country, focusing on areas with moderate-to-high malaria-transmission.

The programme is designed to provide evidence and experience toward WHO policy-recommendations on the wider use of the vaccine. The programme aim to monitor reductions in child deaths, vaccine-uptake, including whether parents are compliant.

The author find a need to write on the result of the Phase III Trial of the vaccine to be used, the RTS,S, beside outlining the basic on malaria-vaccine development.

Finally, the remaining vaccine(s) in development are talked on.