A study on knowledge regarding HIV/AIDS, their sexual practices and seroprevalence of syphilis/HIV among taxi-drivers in Yangon

Aim-To study a knowledge regarding HIV AIDS, sexual practices and sero-prevalences of syphilis/HIV among taxi-drivers. A cross sectional study on 120 respondants of taxi-drivers from Yangon Division Buses Control Committee was carried out by using the systematic random sampling method with self-administered questionnaire. Majority of taxi-drivers have better knowledge on mode of transmission and little knowledge on ways which do not transmit HIV. Most of them did not know proper use of condom. No case of HIV sero-positive were detected at the time of study.

The effect of tetanus toxoid in leprosy patients.

Since cases of lepra reaction following smallpox vaccination and BCG vaccination had been reported the effect of tetanus immunisation on leprosy patients (whether it may provoke a lepra reaction or not) was studied. Three doses of purified tetanus toxoid (one ml initially, one ml after six weeks and one ml after six months) were given to 357 leprosy patients and 60 patients living in the same environ were followed as controls. The antibody response following immunisation was followed in six lepromatous leprosy patients using toxin antitoxin neutralisation test at the Lf/1000 level in mice and in three of them the antibody titre of leprosy patients rose to satisfactory level. The number of lepra reactions in these patients was monitored for nine months (two months before vaccination, during the six months period of vaccination and one month after the last dose of vaccine). There was no significant rise in the number of patients with reaction following the vaccination.

An outbreak of plague in Hlegu, Burma in 1977.

An outbreak of plague occurred in Hlegu Town, Burma in February and March 1977. Altogether 14 bubonic plague cases, with 2 deaths were reported, mostly children under 15 years of age. Twice as many males as females were affected. A retrospective investigation showed that a rat fall took place in the last week of January. Only 9.5% of the rodents which died in the epizootic were found to be infected with Y. pestis; this apparent low infection rate probably resulted from the inclusion in the survey of some dead rats which died of other causes. 14.5% out of 48 trapped rodents were found to be serologically positive. The general flea and cheopis indices were rather high, perhaps because fleas were found to be partially resistant to DDT and also because spraying of insecticide did not effect fleas on the hosts. The cheopis index in Hlegu Town was 1.17, and less than 0.5 in Hlegu suburb (Yankin-Yat) where no epizootic was reported. An active case search revealed 76 suspected plague cases out of which 11 were found to have bubonic plague. A field trial showed that plague vaccination during the outbreak did not result in a rise of detectable antibodies in persons inoculated.

Epidemiological features of skin diphtheria infection in Rangoon, Burma.

A survey for skin diphtheria was carried out on 493 patients with skin lesions who were attending Veneral Diseases & Dermatology Clinic in Rangoon in 1971. 63.8% of the patients had C. diphtheriae in their skin lesions. All ages and both sexes were equally affected. Skin lesions yielding C. diphtheriae on culture were indistinguishable from those associated with other bacteria including ecthyma, pyoderma and secondarily infected with parasitic infections. Out of 108 strains tested 18.5% were found to be toxigenic, mainly intermedius. No toxigenic gravis strain was encountered. No relation existed between the type of lesion and the type or toxigenicity of the infecting strain. 75% of these toxigenic strains were isolated from children under 5 years of age. The phage types of toxigenic strains isolated were: II-IV, XII, Ph r, 8, 19-20, III, IVII and IV.

Outbreaks of plague in nonendemic areas in Burma in 1976

Outbreaks of human bubonic plague cases were reported in several nonendemic areas in the country. These outbreaks were reported from Kachin State (135 cases), Arkan State (55 cases), Mon State (21 cases), Pegu Division (70 cases), Kayah State (58 cases), Rangoon City (5 cases), northern and eastern parts of Shan State (9 cases), and Maymyo (7 cases). A total of 678 and 52 deaths were reported in the country up to the week ending 18-12-76 out of which 360 cases with 44 deaths were from nonendemic areas. Almost all of the towns and villages affected were located on major trade routes which have direct connection with endemic areas in central Burma. The case fatality rate in nonendemic areas ranged from 0 to 75

, the overall fatality rate being 12.2

. This high rate was mainly due to the late recognition of the cases. The outbreaks in the plain areas occurred from January to May expect in Shwegu in Kachin State and Rangoon City while in the hilly regions it occurred from May to December. The peak incidence was observed in March in the plain areas and in August in hilly regions. The epizootics preceeded the outbreaks by one to 8 weeks. Unpaired serum samples tested serologically at the National Health Laboratory revealed 57

positivity rate. Higher positive rate is expected should paired serum samples be tested.

Dengue haemorrhagic fever in Burma.

Although sporadic from 1965 to 1969, a major outbreak of dengue haemorrhagic fever (DHF) occurred for the first time in Rangoon in 1970. Since then the disease has occurred every year in Rangoon and is now observed to be expanding to other urban areas in the country. The clinical diagnosis of DHF was confused by concurrent outbreaks of influenza A in 1971 and influenza A and B in 1972. A laboratory study of 3,447 clinically diagnosed haemorrhagic fever cases showed that 1643 cases (47.8%) were due to dengue and chikungunya, 296 (8.6%) to influenza A, 85(2.5%) to influenza B, 12(0.3%) to measles and 1411(40.8%) were of unknown aetiology during the 5 year period 1970-1974. Ae. aegypti mosquitoes are widely distributed in the country up to and including 900 meters above sea level but breeding is not found above that altitude. The absolute larval population which is highest in July as well as landing rate correlated with the peak incidence of DHF cases.

Insecticide susceptibility of some vector fleas and mosquitoes in Burma.

Rat fleas and mosquitoes are insect vectors of public health importance in Burma. Plague is endemic in Central Burma and DDT has been the principal insecticide used for its control to date. Dengue haemorrhagic fever, recently introduced and transmitted by Aedes aegypti, has been spreading to major towns since 1971. The rodents, Rattus rattus, R. exulans, Bandicota bengalensis, Mus musculus, as well as shrews were commonly caught during routine trapping in the country. Rattus norvegicus, prevalent in Rangoon City, is not found in Central Burma. The rat fleas, Xenopsylla cheopis and X. astia, were found to be infesting these rodents, the former being the principal vector of plague. Insecticide susceptibility tests have been carried out periodically in plague endemic areas and Rangoon since 1966 and it is now observed that rat fleas in most of these endemic towns and Rangoon Port are no longer susceptible to DDT. Subsequent rechecks in towns where fleas became resistance to DDT show that fleas are persistently resistant to the insecticide. Aedes aegypti is found to be highly prevalent both in rural and urban areas of almost every major town and townships below 900 meters. Insecticide susceptible tests on this mosquito in limited areas show that the mosquito is generally resistant to DDT but susceptible to other insecticides. With the development of DDT resistance in fleas, it is now necessary to change to an effective insecticide in the control of plague in Burma.

Epidemiological features of dengue and chikungunya infections in Burma.

A serological survey for antibody to dengue and chikungunya was carried out in all 14 divisions and states and 2 border towns in Burma during 1973-74. Dengue HI antibody prevalence rate of less than 10% was observed in Arakan and Shan States, 10 to 30% in the Irrawaddy, Pegu, Mandalay Divisions and Kachin, Mon and Karen States, 31 to 60% in Sagaing Division, and over 60% in Rangoon, Magwe and Tenasserim Divisions. Similarly, chikungunya HI antibody prevalence rate of less than 10% was observed in Arakan State, 10 to 30% in the Irrawaddy, Pegu, Mandalay and Sagaing Divisions and Kachin State, 31 to 60% in Rangoon Division and Mon State. Both dengue and chikungunya antibodies were detected where Aedes aegypti mosquitoes were prevalent but the antibody prevalent rates were not directly proportional to the premises index. No HI antibody to dengue nor chikungunya was detected in Aedes aegypti free hilly areas, Chin and Kayah States, but was detected in the Shan State, Dengue and chikungunya infections were observed both in rural and urban populations. Dengue and chikungunya infections affected all socioeconomic classes in Rangoon equally but in Mandalay high socioeconomic class was nearly 3 times less affected than lower socioeconomic class. The infrequencies of dengue and chikungunya infections were observed to be 2 to 3 times higher in residents of Rangoon City than those of other towns. In Rangoon the antibody prevalence rates to dengue increased progressively with age while in other towns no appreciable increase in rates with age was observed. Both sexes were equally affected. This study provides strong circumstantial evidence that dengue and chikungunya viruses are highly and widely distributed throughout Burma, and that new outbreaks of haemorrhagic fever could occur in previously free areas following introduction of dengue viruses into populations previously exposed to one type of dengue.

Plague epidemic in Mandalay, 1966-67

(1) Epidemic (and epizootic) of plague in Mandalay during winter months of 1966-67 was presented. (2) Mandalay City is situated in plague endemic zone of the country ; plague infection could be present in or around the city. (3) The present epidemic was due to "carry-over" of rodent plague of 1966, which spread through out the city. Growth of susceptibles among rodents created a situation ready to explode into severest epizootic. (4) Possibility of natural foci infection round about the city as discussed.