Detection of HIV type 1 env subtypes A, B, C, and E in Asia using dried blood spots: a new surveillance tool for molecular epidemiology

Global surveillance of HIV-1 subtypes for genetic characterization is hampered by the biohazard of processing and the difficulties of shipping whole blood or cells from many developing country regions. We developed a technique for the direct automated sequencing of viral DNA from dried blood spot (DBS) specimens collected on absorbent paper, which can be mailed unrefrigerated in sturdy paper envelopes with low biohazard risk. DBS were collected nonrandomly from HIV-1-infected, mostly asymptomatic, patients in five Asian countries in 1991, and shipped via airmail or hand carried without refrigeration to Bangkok, and then transshipped to North America for processing. After more than 2 years of storage, including 6 months at ambient temperatures, proviral DNA in the DBS was amplified by nested PCR, and a 389-nucleotide segment of the C2-V3 env gene region was sequenced, from which 287 base pairs were aligned and subtyped by phylogenetic analysis with neighbor-joining and other methods. From southern India, there were 25 infections with subtype C and 2 with subtype A. From Myanmar (Burma), we identified the first subtype E infection, as well as six subtype BB, a distinct cluster within subtype B that was first discovered in Thailand and that has now appeared in China, Malaysia, and Japan. From southwest China, one BB was identified, while a "classical" B typical of North American and European strains was found in Indonesia. From Thailand, five DBS of ambiguous serotype were identified as three B, one BB, and one E. A blinded control serotype E specimen was correctly identified, but a serotype BB control was not tested. Most HIV-1 in southern India appears to be env subtype C, with rare A, as others have reported in western and northern India. The subtypes BB and E in Myanmar, and the BB in China, suggest epidemiological linkage with these subtypes in neighboring Thailand. DBS are a practical, economical technique for conducting large-scale molecular epidemiological surveillance to track the global distribution and spread of HIV-1 variants.

Cost effectiveness and cost utility of preventing trachomatous visual impairment: lessons from 30 years of trachoma control in Burma

AIMS/BACKGROUND

This paper reports on the findings of a cost and effectiveness study of the trachoma control programme (TCP) in Burma. The TCP began in 1964 employing non-surgical interventions (community education and mass treatment with topical antibiotics) and surgical correction of trichiasis.

METHODS

Fixed and variable costs of the TCP are assessed over 30 years (1964-93) and apportioned to either surgical or non-surgical interventions. The change in the prevalence of trachoma blindness during this period is used to calculate cases of visual impairment prevented by the TCP. The years of life saved because of premature mortality averted and from living in a handicapped state are added to yield a single measure of utility called handicap adjusted life years (HALYs).

RESULTS

The cost effectiveness of the TCP is $54 per case of visual impairment prevented: $193 and $47 for surgical and non-surgical interventions respectively. The cost utility of the TCP is $4 per HALY averted: $10 and $3 for surgical and non-surgical interventions respectively. Results are highly sensitive to the 1965 prevalence of blindness, the choice of discount rate, and the effectiveness of both interventions.

CONCLUSIONS

Thirty years of trachoma control in Burma are associated with a remarkable decline in trachomatous blindness. Both surgical and non-surgical interventions are cost effective means of preventing trachomatous visual impairment. Discussion focuses on methodological limitations and implications for research and policy.

Leprosy in Myanmar, epidemiological and operational changes, 1958-92

The registered caseload and prevalence of leprosy have declined in Myanmar from a peak of 86.2 per 10,000 population (95% CI 85.43-86.97) in 1973-77 to 26.82 (95% CI 18.46-35.18) in 1988-92. The new case detection rates have also declined from 7.41 per 10,000 (95% CI 6.3- 8.52) in 1968-72 to 1.96 (95% CI 1.43-2.52) in 1988-92. The increase in the multibacillary proportion of new cases from 11.85% (95% CI 11.84-11.86) in 1968-72 to 40.54% (95% CI 37.2-43.88) in 1988-92 and the decline in proportion of new cases under 14 years of age from 26.81% (95% CI 26.8-26.82) in 1968-72 to 11.22% (95% CI 10.92-11.52), coupled with the finding of declining detection rates among school children and in mass village surveys could mean that the incidence of leprosy may be declining.

Correlation of hydrogen and methane production to rice carbohydrate malabsorption in Burmese (Myanmar) children

Rice carbohydrate malabsorption is common in Burmese village children and adults and may contribute to diminished growth. Its diagnosis depends on a rice breath hydrogen test, which has limitations. Almost 20% of Burmese children under age 5 produce methane, compared with less than 7% of children in Africa and Hong Kong. If an increased carbohydrate load in the colon due to rice malabsorption provides increased substrate for methanogenic bacteria in the left colon, higher fasting breath methane concentrations might be a simpler method of diagnosing rice malabsorption. We tested breath hydrogen and methane over a 4-h period and did anthropometric measurements in 142 subjects, 79 children, and 63 adults. Seventy percent of children were rice-malabsorbers. Methane production occurred in 20% of children under 5 years of age and increased to 60% of adults. There is an association of rice malabsorption with reduced length. There was not correlation between rice malabsorption and breath methane, and the concentration of breath methane does not, therefore, indicate rice absorption status and cannot replace rice breath hydrogen tests.

Genotype determination of three dengue type 2 virus strains from Myanmar by sequencing E/NSI gene junction

Genotype of three dengue-2 virus strains from Myanmar was determined as genotype II by sequencing 240 nucleotide long fragment across the E/NS1 gene junction by the primer extension dideoxy chain termination method, applying direct sequencing of the PCR product. These strains were isolated from a dengue shock syndrome (DSS) patient and two patients with dengue hemorrhagic fever (DHF) grade 1, in Yangon (Rangoon), Myanmar (Burma), in 1987. Sequence homology of all three strains were highest (96%) to New Guinea C strain (genotype II), lesser homology (93%) to Jamaican 1409 strain (genotype III), and the least homology (91%) to PR 159/S1 strain (genotype I). Two DHF strains revealed only 2 nucleotide and 3 nucleotide differences compared with DSS strain, all at the 3rd position of the codons which resulted in silent mutations.

Intestinal volvulus: an experience in a developing country

Eighty-two children (47 boys and 35 girls) underwent surgery for a variety of causes resulting in volvulus. There were 20 neonates, 13 infants, 34 patients aged 1 to 5 years, and 15 children above 5 years of age. The majority (88%) of the patients were admitted in a state of shock and dehydration. Peritoneal signs were present in 74% of the patients. The resection rate was 61%. A high mortality rate of 38% was encountered, which was attributed to septicemia, shock, and multiorgan failure. The preventive health programs that are being actively implemented together with the improvements made in the transport and referral systems have fortunately resulted in much-improved survival rates in the recent few years.

Cryptosporidiosis in Myanmar infants with acute diarrhea

Cryptosporidiosis has been found in Myanmar for the first time in infants presenting with a mild transient form of acute diarrhea. A total of 203 fecal samples collected from those infants were examined by Kinyoun's acid fast modified method. 3.4% of infants between 2 and 11 months of age were found passing cryptosporidium oocysts. All cases presented with features consistent with findings reported by other authors from developing countries. Cryptosporidium was the sole microorganism isolated. Hence, cryptosporidiosis may be responsible for acute diarrhea in these Myanmar infants.

The impact of national measles immunization programme on measles admissions to the major children's hospital in Yangon

To ascertain whether measles vaccination was associated with reduced measles associated mortality and morbidity in the Yangon Children's Hospital (YCH), the hospital records of children admitted to YCH in 1985 and 1989 with the diagnosis of measles or measles associated conditions, were analysed retrospectively. Measles vaccination was associated with a 90.7% reduction of deaths directly attributed to measles or ascribed to diarrhoea, respiratory illness, malnutrition or fits. An 85% reduction in the percentage of medical admissions related to measles and measles associated conditions was also seen. The case-fatality rate from measles declined from 25.3% to 15.6%. We conclude that measles immunization has been associated with a marked reduction in morbidity and mortality.

A symposium on containment of mefloquine-resistant falciparum malaria in Southeast Asia with special reference to border malaria

Important questions related to the factors responsible for and contributing to the origin and spread of multi-drug resistant falciparum malaria at the Thai-Cambodian and Thai-Myanmar border areas are discussed, including the current geographical distribution of multi-drug resistance and the prevention and control of this phenomenon. Specific recommendations are made on epidemiological surveillance, drug deployment, vector control, and the problem of migration which plays a major role in the dissemination of resistant parasite populations. The recent advent of mefloquine resistance of P. falciparum in Thailand may serve as fair warning in the absence of stern measures for preventing the occurrence of resistance to the next and currently last line of antimalaria drugs, especially those with a long half-life, in areas with intensive, uncontrolled malaria transmission, such as tropical Africa.

Maternal and newborn thyroid hormonal profile in a non-goitrous area of Myanmar

Serum thyroxine (T4), triiodothyronine (T3) and thyrotropin (TSH) levels of 325 pairs of blood samples from the newborn infants and their mothers were determined with the aim of establishing the thyroid hormonal profile of the newborn babies and their mothers in a non-goitrous area of Myanmar. The mean +/- SEM cord serum T4, T3 and TSH levels were 117.47 +/- 1.92 nmol/l, 0.57 +/- 0.02 nmol/l and 6.41 +/- 0.84 mu/ml respectively. The corresponding maternal levels were 146.29 +/- 2.06 nmol/l, 2.33 +/- 0.04 nmol/l and 2.59 +/- 0.17 mu/ml maternal serum T4 and T3 levels were significantly higher than the corresponding cord serum values (p < 0.0001 in both cases) and maternal TSH level was significantly lower than cord level (p < 0.0001). Maternal and cord T4, T3 and TSH levels of premature infants were not significantly different from those of mature infants. Similarly maternal and cord hormonal levels of male infants were not significantly different from those of female infants.

Permethrin-impregnated bed nets for the prevention of malaria in schoolchildren on the Thai-Burmese border

A double-blind controlled trial was undertaken from August 1990 to February 1991 among Karen children on the Thai-Burmese border to evaluate the effects on malaria incidence and prevalence of permethrin-treated bed nets. Three hundred and fifty schoolchildren, aged 4 to 15 years, were allocated at random to receive either a permethrin-impregnated net or a non-treated net. The incidence of malaria infections, confirmed by a blood film, was assessed during 6 months. Three surveys were conducted, on admission and 3 and 6 months later, to measure the prevalence of infections and spleen rates. Compliance was assessed by monthly home visiting. The use of permethrin-treated bed nets reduced the number of parasitaemic Plasmodium falciparum infections by 38% and the number of symptomatic episodes by 42%. The number of P. vivax malaria attacks was similar in each group. The prevalence of positive blood films in the 2 groups did not change significantly during the study. A reduction in spleen rate by 50% in both groups at the end of the study period could not be related to the overall use of nets. Compliance was high and no side-effect was reported. The long-term effects on morbidity and mortality need to be assessed after distribution of permethrin treated bed nets at the village level.

Mefloquine prophylaxis prevents malaria during pregnancy: a double-blind, placebo-controlled study

A double-blind, placebo-controlled study of mefloquine antimalarial prophylaxis in pregnancy (> 20 weeks of gestation) was conducted in 339 Karen women living in an area of multidrug-resistant malaria transmission on the Thai-Burmese border. Mefloquine gave > or = 86% (95% confidence interval [CI], 59%-94%) protection against Plasmodium falciparum and complete protection against Plasmodium vivax infections. Mefloquine prophylaxis was well tolerated; use of an initial loading dose (10 mg/kg) was associated with transient dizziness, but there were no other significant adverse effects on the mother, the pregnancy, or infant survival or development (followed for 2 years). Falciparum malaria was associated with maternal anemia and a mean reduction in birth weight in gravidae I, II, and III of 225 g (95% CI, 26-423). Maternal anemia at delivery (hematocrit < 30%) was associated with increased infant mortality: 26% versus 15% (relative risk, 1.9; 95% CI, 1.1-3.2). Mefloquine is safe and effective for antimalarial prophylaxis in the second half of pregnancy.

[Incidence and prevalence of serotypes of enteroaggregative Escherichia coli from diarrheal patients in Brazil, Myanmar and Japan]

By using HeLa cells, we tried to detect enteroaggregative Escherichia coli from stock strains derived from infants with or without diarrhea in Brazil and Myanmer, and from diarrheal patients in Osaka, Japan. Enteroaggregative E. coli was detected from 7.9% in diarrheal cases, 5.6% in control cases in Brazil and from 5.4% in diarrheal cases, 3.4% in control cases in Myanmar. A total of 38 strains that showed aggregative adherence to HeLa cells was examined for colony hybridization with the 32P-labeled EAggEC probe. Thirty-four strains hybridized with the EAggEC probe, while 4 strains did not hybridize with the probe, suggesting an existence of another aggregative factor. Seventeen of the 38 strains were O-antigen serotypeable. Eight strains belonged to serogroups O44, O86, O111, O125 and O126, which have been considered to be enteropathogenic E. coli serogroups. Most of the 38 strains were H-antigen serotypeable.

An epidemic outbreak of hepatitis E in Yangon of Myanmar: antibody assay and animal transmission of the virus

An epidemic outbreak of hepatitis E occurred in an army recruit camp of Yangon, Myanmar, in October 1989. One hundred and eleven patients among 600 residents were hospitalized. As high as 83.7% of these patients were positive for the acute phase antibody against hepatitis E virus by an enzyme-linked immunosorbent assay developed in our laboratory. Also, 30.6% of 49 symptom-free residents examined were positive for the antibody. We prepared a stool extract from six patients and inoculated it into 10 rhesus monkeys for a series of three sub-passages. All of them developed acute biochemical hepatitis along with an elevation of antibody levels. A rechallenge with viruses of the present outbreak failed to provoke hepatitis in two monkeys that had previously recovered from acute hepatitis caused by an isolate of sporadic hepatitis E of the same area. Similarly, the rechallenge of the sporadic strain did not induce hepatitis in two monkeys that had been previously infected with the epidemic virus. These data suggested that the subjects would obtain neutralizing antibodies against the hepatitis E virus once infected, and many adult inhabitants of the endemic area had no protective antibodies and were still susceptible to hepatitis E infection.

Comparison of saliva and serum for HIV surveillance in developing countries

Saliva has been proposed as a non-invasive alternative to serum for HIV antibody testing. In a field study in Myanmar (formerly Burma), we evaluated such an alternative to identify the frequency of HIV infection in a surveillance programme of high-risk and low-risk sentinel groups. Duplicate vials of saliva and serum were collected from 479 high-risk and 1039 low-risk subjects. One vial of each pair was analysed blind in two laboratories, one in the USA and the other in Myanmar. The US laboratory followed WHO confirmatory strategy III with three different enzyme-linked immunosorbent assays (ELISAs), while the laboratory in Myanmar followed strategy I with one ELISA. Serum testing in the US was the gold standard. The Cambridge ELISA with saliva was a more effective surveillance tool (sensitivity 90.5%, specificity 99.5-100%) for describing the frequency of subjects with HIV antibodies than the serum ELISA supplied to Myanmar by WHO (95.9% and 98.3%, respectively). Saliva is recommended as a safe and effective alternative to serum for HIV antibody testing with ELISA in surveillance programmes in developing countries.

Molecular cloning and sequencing of the Mexico isolate of hepatitis E virus (HEV)

Hepatitis E virus (HEV) is the major causative agent of hepatitis E or what was formerly known as enterically transmitted non-A, non-B hepatitis. The disease has a worldwide distribution but occurs principally in developing countries in any of three forms: large epidemics, smaller outbreaks, or sporadic infections. Genetic variation of different HEV strains was previously noted and it will be important to determine the extent to which this variation may pose problems in the diagnosis and treatment of HEV infection. To analyze differences at the genetic level between HEV(Mexico; M) and the previously characterized HEV(Burma; B) and HEV(Pakistan; P) isolates, overlapping cDNAs were cloned from samples obtained from an infected human and an experimentally inoculated cynomolgus macaque. These cDNA clones, representing the nearly complete (7185-bp) genome of HEV(M), confirmed an expression strategy for the virus that involves the use of 3 forward open reading frames (ORFs). The HEV(M) strain has an overall 76 and 77% nucleic acid identity with the HEV(B) strain and HEV(P) strain, respectively; however, the degree of sequence variation was not uniform throughout the viral genome. A hypervariable region was identified in ORF1 that exhibited a 58 and 54% nucleic acid sequence and 13% amino acid similarity with the Burma strain and the Pakistan strain, respectively. A large number of the nucleotide differences occurred at the third codon position, with the deduced amino acid sequences similarity of 83, 93, and 87% between HEV(M) and HEV(B) isolates in ORF1, ORF2, and ORF3, respectively, and with 84, 93, and 87% amino acid identities between HEV(M) and HEV(P) isolates in ORF1, ORF2, and ORF3, respectively. The nucleotide sequences derived from the highly conserved regions of HEV genome will be useful in developing polymerase chain reaction-based tests to confirm the viral infection. Knowledge of the extent of the sequence variation encountered with HEV will not only aid in the future development of diagnostic and vaccine reagents but also further our understanding of how HEV strain variation might impact the pathological outcome of infection.

Risk factors for the development of persistent diarrhoea and malnutrition in Burmese children

To identify socioeconomic and behavioural risk factors for development of persistent diarrhoea and malnutrition in children, a case-control study was carried out in Burma. Cases were 67 children 1-59 months old hospitalized for diarrhoea lasting > 14 days and complicated by severe malnutrition; for each case, a healthy control child was selected who was age- and sex-matched from the same neighbourhood. Homes of cases and controls were visited for interviews and for direct observation of household child-care practices. Risk factors were catalogued and calculations made for relative risk and etiologic fractions. Risk factors that were associated with persistent diarrhoea and malnutrition included low family income, low education of mothers, unhygienic latrines, flies in the house and on the child, dirty appearance of child and mother, mother not using soap and water when washing child's hands, defaecation of child on floor, breastfeeding on demand, child eating food from floor, not feeding recommended weaning foods, and lack of knowledge by mother about causes of diarrhoea and about foods that prevent malnutrition. These results indicated that persistent diarrhoea and malnutrition in Burma is caused by a complex of several interrelated socioeconomic factors, unsanitary behaviour pertaining to personal hygiene, the practice of demand breastfeeding and lack of certain weaning foods, and low education of mothers who showed less knowledge about causes of diarrhoea and prevention of malnutrition.

The effect of artemether plus mefloquine on Myanmar patients with complicated falciparum malaria

The effect of artemether plus mefloquine versus quinine on 35 patients with complicated falciparum malaria including 5 patients with cerebral malaria were studied. All patients treated with the artemether-mefloquine combination survived and all were free from toxic effects of the drugs. Three patients on quinine therapy died. The mortality rate was 8.5%. The mean parasite clearance time of patients treated with artemether plus mefloquine was significantly shorter than those treated with quinine but there was no significant difference in the mean fever clearance of the two groups of patients. There was no recrudescence with artemether and mefloquine; the recrudescence rate was 5.5% with quinine. The study showed that the artemether-mefloquine combination is superior to quinine for the treatment of patients with complicated falciparum malaria, including cerebral malaria.

Epidemiology of small bowel bacterial overgrowth and rice carbohydrate malabsorption in Burmese (Myanmar) village children

Breath hydrogen tests were performed after a rice meal (3 g of cooked rice/kg of body weight, equivalent to 1 g of carbohydrate/kg of body weight) on 256 village children (age range 1-59 months) who were known hydrogen (H2) producers. Anthropometric measurements were made every three months and growth rates were calculated. A breath H2 excretion pattern that suggested small bowel bacterial overgrowth (SBBO), which was recognized as a transient maximum level of 10 ppm or more at 20-, 40-, or 60-min breath samples following the rice meal, was present in 53 (20.7%) children, and was more frequent in children 36-47 and 48-59 months old. This breath H2 excretion pattern was detected in 48 (33.3%) of 144 children who were rice malabsorbers (greater than 10 ppm H2 above baseline values in one of the breath samples taken between 90 and 240 min), and in only five (4.5%) of 112 rice absorbers. Children who had SBBO had a high relative risk (10.7) of being rice malabsorbers. Rice malabsorbers have a high relative risk (59.7) of having faltered growth, accompanied by a large etiologic fraction (94%). This same risk (6.68) and an etiologic fraction of 62% exist in children with untreated SBBO. These findings emphasize the need for interventions aimed at reducing the prevalence of SBBO or similar conditions as detected by the breath H2 excretion pattern to prevent rice malabsorption and growth faltering.

Indian hepatitis E virus shows a major deletion in the small open reading frame

Enterically transmitted non-A, non-B hepatitis virus (HEV), the causative agent for sporadic and large epidemic outbreaks in developing countries, contains a positive-sense single-stranded RNA genome. The genome of the virus encodes three open reading frames (ORF1, ORF2, and ORF3). The gene segment corresponding to the small open reading frame (ORF3), overlapping between ORF1 and ORF2, was synthesized by reverse transcription-polymerase chain reaction (RT-PCR) from a number of previously identified HEV-positive clinical specimens. A DNA fragment of 166 bp was consistently obtained from all the clinical specimens. This small fragment was cloned, sequenced, and found to contain an open reading frame encoding only 41 amino acid residues. Comparison of our results with that of geographically related Burma HEV suggests a major inframe deletion of 246 bp in the ORF3 of Indian strain. The protein encoded by ORF3 does not appear to be useful for early serodiagnosis as a synthetic peptide deduced from the truncated ORF3 failed to show any demonstrable immunoreactivity against HEV-infected acute phase sera in an enzyme-linked immunosorbent assay.

Development of a simple indirect enzyme-linked immunosorbent assay for the detection of immunoglobulin M antibody in serum from patients following an outbreak of chikungunya virus infection in Yangon, Myanmar

During 1984, 1548 children were admitted to the Yangon [Rangoon] Children's Hospital in Myanmar [Burma] with haemorrhagic fever. No evidence of recent dengue infection was found in 577 of the 803 children from whom paired sera were obtained, raising the possibility of reappearance of Chikungunya virus infection in Myanmar. An enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Chikungunya virus immunoglobulin M (IgM) antibody was prepared and standardized using only reagents which are commercially available or which could be prepared without the use of sophisticated equipment. While there was 90% agreement between haemagglutination inhibition (HI) tests and the IgM ELISA in the diagnosis of acute Chikungunya virus infections, 12 additional patients with stationary anti-Chikungunya virus HI antibody titres could be identified as having acute Chikungunya infections using the ELISA. Furthermore, the ELISA could identify twice as many patients (31/103) at the time of admission to hospital as the HI test (15/103). There was no false positive IgM reaction with the ELISA which could be attributed to the presence of rheumatoid factor. Using the test, 103 of a sample of 163 children who presented to the Yangon Children's Hospital with fever/haemorrhagic fever were diagnosed as Chikungunya patients, 4 had possible dual Chikungunya and dengue infections, 16 had dengue, 30 had neither Chikungunya nor dengue infections, and a definitive diagnosis could not be made for 10 patients. Routine use of the ELISA would alert authorities to future outbreaks of Chikungunya virus infection and avoid admission to hospital of patients with a non-life-threatening viral disease.

An epidemiologic study of 70 oral cancer cases at the Institute of Dental Medicine, Yangon, Myanmar, 1985-1988

This study shows that in Myanmar, South-East Asia, the prevalence of oral cancers is a serious fact as they rank fifth among all cancers being known there. On the 70 oral cancer cases reported at the Institute of Dental Medicine, Yangon, the findings stressed that most patients, male or female, came from the metropolitan division (Yangon), had smoking and chewing habits. Also most of these patients came to hospital only at the severe and late stage. It confirms us in our opinion that early diagnosis and prompt treatment are a necessity.

House-dust mite allergy and eosinophilia in patients with asthma in Rangoon (Yangon)

Skin tests were done by prick and intradermal techniques, using house dust mite (Dermatophagoides pteronyssinus) antigen on 35 patients with early onset asthma, 33 with late onset asthma, 43 with asthma and frequent cough with sputum production (chronic bronchitis) and 30 control subjects. Absolute blood eosinophil and sputum eosinophil (as percentage of leukocytes) counts were performed on each patient. Positive skin tests to house dust mite antigens were significantly more frequent in each of the patient groups (35-75%) than in control subjects (0%), but were not significantly different among the three groups of asthmatics. All three groups of asthmatics had significantly higher mean blood absolute eosinophil counts and sputum eosinophil counts than control subjects, eosinophilia being most frequent in patients with early onset asthma. These findings suggest the importance of exposure to house dust mite antigens in the development of asthma in patients in Rangoon (Yangon), Burma (Myanmar).

Study of the malaria situation in forested foothill and nearby plain areas of Myanmar

A longitudinal demographic-parasitological survey on malaria was conducted at 10 weekly intervals starting from September in one foothill village with the population of 1,095 and one epidemiologically comparable plain village with the population of 962 in Kyauktaga township, Bago division, 120 miles north of Yangon. The objective was to describe and analyse the current malaria situation in a forested foothill area and an adjacent plain area. Ten weekly blood film collections for malaria parasite examination, six monthly sera collections on filter paper for serological examination from the whole study population and ten weekly splenic measurements from 2-9 year children were done. The malaria parasite rate in the foothill area was invariably higher than that in the plain area in all age groups throughout the study period. Moreover, the parasite rate decreased with the increase in distance from the forested foothill area indicating that the deep forest malaria may have some influence on the foothill villages. The total age specific parasite rate in foothill villages was found to be highest in the 5-8 year age group and decreased as the age advanced which may be due to the increasing immunity. The study revealed the presence of local transmission in the foothill village. From these data it is evident that new village sites should be chosen at least 5 miles away from the forest fringe and the malaria control measures in the plain area should utilize chemoprophylaxis and effective chemotherapy focusing on the people who travel into the forest.

The impact of three-monthly age-targetted chemotherapy on Ascaris lumbricoides infection

The impact of 3 chemotherapeutic regimens at 3-monthly intervals against Ascaris lumbricoides infection, targetted at under 15 years old children with and without initial mass chemotherapy, and at 2-12 years old children, was studied in three Myanmar [Burmese] rural communities over a period of 2 years. Computation was made of prevalence and intensity (worm burden) of Ascaris infection, and other parameters for estimation of basic reproductive rate (R0) of the parasite and of the proportion of target age group to be treated 3-monthly (g) by employing the mathematical model for targetted chemotherapy. The 3 treatment regimens were almost equally effective in reducing prevalence and intensity in both the targetted and non-targetted age groups. Ascaris transmission in each of the 3 communities was interrupted, as indicated by the values of mean worm burden per person. The findings are compared with those of other similar studies and the reasons for the impact are discussed. The possible impact in similar endemic areas of applying the mathematical model predictions for age-targetted chemotherapy in controlling ascariasis is also discussed.

Malaria during pregnancy in an area of unstable endemicity

A prospective study of malaria during pregnancy was conducted between September 1986 and December 1989 in an area of unstable (mesoendemic) malaria transmission on the Thai-Burmese border. Antenatal clinics were set up in camps for displaced persons of the Karen ethnic minority and 1358 pregnant women were enrolled at a mean estimated gestational age of 23 weeks (standard deviation 5.7 weeks) and were followed weekly until delivery. Malaria developed in 505 women (37.2%); 80.2% of infections were Plasmodium falciparum, 17.1% were P. vivax, and 2.7% were mixed. Primigravidae were infected more commonly than multigravidae: 153/322 (47.5%) compared with 318/953 (33.3%) (P less than 0.001). The incidence of malaria declined from the 20th week of gestation (12%) towards term (4.4%). Most infections were detected before symptoms developed, and there were no deaths associated with malaria. Despite this, malaria was associated with an overall 123 g reduction in birthweight (95% confidence interval [CI] 34-212 g). This reduction was largely accounted for by lower birthweights of babies born to infected primigravidae (mean reduction 151 g, 95% CI 21-282 g) and women in their 2nd and 3rd pregnancies (mean reduction 185 g, 95% CI 84-286 g). The incidence of anaemia requiring treatment was higher in women who developed malaria, 149/420 (35.4%) compared with 191/670 (28.5%), and was proportional to the number of parasitaemic episodes. Thus, despite regular antenatal clinic attendance with prompt detection and treatment of malaria (the currently employed antimalarial strategy in areas with multidrug-resistant P. falciparum), malaria still had a significant adverse effect on pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Mefloquine-resistant falciparum malaria on the Thai-Burmese border

Mefloquine is the treatment of choice for uncomplicated multiresistant falciparum malaria, and in combination with sulphadoxine and pyrimethamine (MSP) at a single dose of 15/30/1.5 mg/kg, respectively, has been used in Thailand for the past 6 years. In 1985-86, MSP cured over 98% of 5192 patients with falciparum malaria on the Thai-Burmese border. 4 years later we studied the efficacy of MSP in 395 patients at the same location. The cure rate at 28 days was 70.8% (95% Cl 67-77.2%). The proportion of early treatment failures (in whom parasitaemia did not clear) had risen from 0.27 to 3.7% (p less than 0.0001). Failure rates were 50% in children under 6 years old, 29% in the 6-15 age group, and 19% in adults (p less than 0.001). Patients with early treatment failure were retreated with 25 mg/kg mefloquine, but 27% had a further recrudescence of infection within 28 days. The mean (95% Cl) serum mefloquine concentration at the time of first recrudescence was 638 (546-730) ng/ml, a value previously associated with successful treatment. Mefloquine concentrations were no lower in those with recrudescent infections than in age-matched successfully treated patients, suggesting that pharmacokinetic factors were not responsible for the high treatment-failure rate. Plasmodium falciparum has developed resistance to mefloquine rapidly, despite the addition of sulphadoxine and pyrimethamine and strict control of drug administration. The MSP combination should now be abandoned.

Neonatal diarrhea at a maternity hospital in Rangoon

Between 1981 and 1986, 1,540 infants born at the Central Women's Hospital in Rangoon were transferred to the Sick Baby Unit because of diarrhea (15.4 per 1,000 live births). Rates among cesarean infants were five times as high as those of infants born vaginally (51.0 and 10.3 per 1000 live births, respectively). One hundred eighty-four of the infants with diarrhea died (case fatality rate = 12 percent). We conclude that neonatal diarrhea is endemic in this large maternity hospital in Burma, and that control efforts should be targeted especially to cesarean and low birthweight infants.

Effect of short-term intermittent antibiotic treatment on growth of Burmese (Myanmar) village children

To test the hypothesis that subclinical enteric infection (such as bacterial overgrowth), rice malabsorption, and growth faltering are causally linked, a field trial of low-dose, short-term, intermittent antibiotic treatment was carried out in 142 hydrogen-producing (by lactulose breath hydrogen test) Burmese village children aged 6-59 months. The children were randomly allocated treatment with metronidazole (20 mg/kg or 5 mg/kg daily), amoxycillin (25 mg/kg daily), or placebo given 1 week per month for 6 months. A cooked rice meal breath hydrogen test was done to classify the children as rice absorbers (RA) or rice malabsorbers (RM) before treatment and monthly on the day before each cycle of treatment. There were no differences between the treatment groups, so they were considered together. Factorial analysis showed that antibiotic treatment did not significantly affect the proportion of RM children. The only significant difference between antibiotic-treated and placebo-treated children's growth was in the subgroup of RM children aged 36-47 months; the antibiotic-treated children had significantly greater linear growth. In other age groups antibiotic treatment had no effect on growth.

Household faecal contamination and diarrhoea risk

We conducted a study in a low-ranking socioeconomic community in Yangon, Myanmar (Burma) to determine the source of household faecal contamination (HFC), devise an index, and associate this index with diarrhoeal incidence in children. Observation was used to collect information on the sources of household faecal contamination (HFC) and a twice-weekly monitoring scheme was employed for determining diarrhoea incidence. A valid household faecal contamination index (HFCI) was developed using three sources of HFC: going about without footwear, indiscriminate defaecation near or under the house, and absence of latrine. The risk of diarrhoea significantly increased from 4.21 to 8.66 per 1000 child-days (P less than 0.001) when HFCI increased from 0 to 3. Although the adjusted rate ratios for the three levels of HFCI were approximately equal to 2.00 (2.16, 1.77, 2.14), they were not statistically significant. Further studies are needed to corroborate the results of what seems to be the first study attempting to associate HFC with diarrhoea incidence.

Measles-associated diarrhoea in the Infectious Diseases Hospital, Rangoon

A study was conducted in the Infectious Diseases Hospital in Rangoon (Burma) to determine the magnitude of measles-associated diarrhoea morbidity and mortality in children under 6 years of age contributing to the overall diarrhoeal morbidity and mortality, and to determine the bacterial pathogens of measles-associated diarrhoea cases. Measles-associated diarrhoea cases occur most frequently in younger age groups (12-23 and 0-11 months). Although not directly comparable, their contribution to the total diarrhoeal cases (8%) was high but the proportion of measles-associated diarrhoeal deaths contributing to total diarrhoeal deaths was lower than the theoretical estimates. A low fatality rate (2%) among the measles-associated diarrhoea cases was found and this suggests a much lower rate in the community. This implies that measles-associated diarrhoeal mortality is probably not a major public health problem in Burma. Chest infection was the most common complication (32%) and was found in the majority of deaths resulting from complicated measles. A definite seasonal distribution of measles and measles-associated diarrhoea cases was found. Only 10% of the stool samples examined were positive for bacterial pathogens and all were shigellae. We found that a significant number of measles-associated diarrhoeal cases were malnourished.

Role of ascariasis in surgical abdominal emergencies in the Rangoon Children's Hospital, Burma

Patients aged 1 month to 12 years admitted with an acute abdominal surgical condition comprising 226 cases with and 206 cases without ascariasis, recorded in the operation theatre registers and in-patients clinical sheets, were studied in relation to morbidity, duration of operation and hospital stay and mortality. Annually, 7.5% of laparotomies were due to complications of ascariasis. Operations for ascariasis accounted for 10.6% of all hospital admissions for an acute abdominal emergency. Also, ascariasis accounted for 26.3% of emergency operations. All operated biliary obstruction cases were due to ascariasis. Moreover, 20.4% of all cases of ascariasis with abdominal complications required operation. The mean ages at operation were higher in Ascaris-induced than in non-Ascaris-induced intestinal obstruction (5.1 vs 3 yr), intussusception (3.5 vs 1.2 yr) and volvulus (4.8 vs 1.7 yr). The durations of operation and hospital stay were longer and case fatality rates higher in Ascaris-induced than in non-Ascaris-induced cases. The importance of this study in relation to the socio-economic benefits of controlling ascariasis is discussed.

Sociodemographic characteristics and incidence of gonorrhoea in prostitutes working near the Thai-Burmese border

A study was conducted to determine the sociodemographic characteristics and incidence of gonorrhoea among the prostitutes working in Mae Sot District, Tak in 1988. Of the 238 prostitutes included in the study, 130 were Thai and 108 were Burmese. About 55% of the Thai group and 65% of the Burmese engaged in prostitution before being 19 years old. Most of them experienced sexual intercourse at early age of life. The charge per sex partner ranged from 50-500 baht (US$2-20), with a median of 100 baht (US$4) for both groups. The Thai prostitutes had a significantly higher mean number of clients per day and received more Thai clients than the Burmese. Anal and oral sex were not commonly practised among these prostitutes. Approximately 14% of the prostitutes' clients in both group used condoms. The mean infection rate of gonorrhoea was significantly greater in the Thai prostitute group than the Burmese. Multiple linear regression analysis revealed that the infection rate of both groups was inversely associated with the percentage of client using condoms and the duration of having been prostitutes, and positively associated with the percentage of Thai clients. The program for STD control should be directed towards the increase use of condoms, spermicides, and other barrier methods, and massive health education program on safer sex to this high risk group and the general population.

Control of ascariasis through age-targeted chemotherapy: impact of 6-monthly chemotherapeutic regimens

A field trial of 6-monthly ascariasis chemotherapeutic regimens targeted at 1-19-, 1-14-, and 5-19-year-olds was carried out in three communities in rural Myanmar to observe the effects on the prevalence, intensity, and morbidity indicators over 2 years. After periodic chemotherapy, the prevalence and intensity of Ascaris infection in age-targeted and non-age-targeted groups fell in all the study areas, more markedly among the 1-19- and 1-14-year-olds. There was also a decrease in the frequency of vomiting of worms, passing of worms per anus, coughing, abdominal pain and treatment of bowel complaints, especially among the treated groups. In addition, there were reductions in the frequency of fever from nonbowel complaints and protrusion of the abdomen among children in the targeted group.

Epidemiology and aetiology of acute childhood diarrhoea in Burma: a rural community survey

Identical epidemiological and microbiological surveys were carried out in a rural community at Intakaw, Burma, in 2 months, one in the hot wet and the other in the cool dry season. The incidence of diarrhoea was highest in children under 3 years old and in the hot wet month when enterotoxigenic Escherichia coli was the predominant pathogen. Rotavirus was the commonest pathogen in the cool dry month but was absent in the hot wet month. Shigellae, salmonellae and campylobacter were isolated in both seasons, but were not significantly commoner in patients than in controls. Vibrios and Yersinia enterocolitica were sought but not found in any specimen.