Doxycycline and rifampicin for mild scrub-typhus infections in northern Thailand: a randomised trial

BACKGROUND

Some strains of scrub typhus in northern Thailand are poorly responsive to standard antirickettsial drugs. We therefore did a masked, randomised trial to compare rifampicin with standard doxycycline therapy for patients with scrub typhus.

METHODS

Adult patients with strictly defined, mild scrub typhus were initially randomly assigned 1 week of daily oral treatment with 200 mg doxycycline (n=40), 600 mg rifampicin (n=38), or doxycycline with rifampicin (n=11). During the first year of treatment, the combined regimen was withdrawn because of lack of efficacy and the regimen was replaced with 900 mg rifampicin (n=37). Treatment outcome was assessed by fever clearance time (the time for oral temperature to fall below 37.3 degrees C).

FINDINGS

About 12,800 fever patients were screened during the 3-year study to recruit 126 patients with confirmed scrub typhus and no other infection, of whom 86 completed therapy. Eight individuals received the combined regimen that was discontinued after 1 year. The median duration of pyrexia was significantly shorter (p=0.01) in the 24 patients treated with 900 mg daily rifampicin (fever clearance time 22.5 h) and in the 26 patients who received 600 mg rifampicin (fever clearance time 27.5 h) than in the 28 patients given doxycycline monotherapy (fever clearance time 52 h). Fever resolved in a significantly higher proportion of patients within 48 h of starting rifampicin (900 mg=79% [19 of 24], 600 mg=77% [20 of 26]) than in patients treated with doxycycline (46% [13 of 28]; p=0.02). Severe gastrointestinal events warranted exclusion of two patients on doxycyline. There were two relapses after doxycycline therapy, but none after rifampicin therapy.

INTERPRETATION

Rifampicin is more effective than doxycycline against scrub-typhus infections acquired in northern Thailand, where strains with reduced susceptibility to antibiotics can occur.

[Impact of Streptococcus pneumoniae on pneumonia in Latin American children. SIREVA-Vigía Group]

Community-acquired pneumonia is one of the leading causes of infant morbidity and mortality. Studies conducted in developing countries indicate that the most serious symptoms of pneumonia are associated with bacterial causes, mainly Streptococcus pneumoniae, followed by Haemophilus influenzae type b. Managing those infections in children under two years of age is hindered by the lack of appropriate vaccines and by the decreased susceptibility of S. pneumoniae to penicillin and other antibiotics. In 1993, at the initiative of the Regional System for Vaccines of the Pan American Health Organization, and with funding from the Canadian International Development Agency, a study was designed to identify the S. pneumoniae capsular types that cause invasive disease in Latin American children under 5 years of age. The objective of the study was to determine the ideal composition of a conjugate vaccine that could be used in Latin America, and the penicillin susceptibility of the S. pneumoniae isolates. The initiative was undertaken in Argentina, Brazil, Chile, Colombia, Mexico, and Uruguay. This report analyzes the information that the participating countries generated on pneumococcal pneumonia. A total of 3,393 children were found with systemic S. pneumoniae infections, of which 1,578 corresponded to pneumonias. The analysis focused on 1,409 cases of pneumonia in Argentina, Brazil, Colombia, Mexico, and Uruguay. Of the children, 63.8% of them were under two years of age. Twelve prevalent capsular types were identified, of which serotypes 14, 5, and 1 were the three most common in the majority of the countries. At the beginning of the study the highest level of penicillin resistance was found in Mexico (47.0%), and the lowest in Colombia (12.1%). Over the 1993-1998 period, resistance to penicillin increased in the five countries. Penicillin resistance was associated with a small number of capsular serotypes, mainly 14 and 23F. The first of those serotypes was resistant to penicillin and to trimethoprim-sulfamethoxazole, and the second was multiresistant. The frequency of resistance to trimethoprim-sulfamethoxazole was high in all of the countries; Argentina had the highest level, 58.0%. A decrease in susceptibility to chloramphenicol was uncommon, except in Colombia, where there was a resistance level of 23.4%. Resistance to erythromycin was low in all the countries, and all the isolates were susceptible to vancomycin.

Improving the monitoring of immunization services in Kyrgyzstan

Following the disbanding of the Soviet Union in 1991, the government of Kyrgyzstan was unable to maintain the previous level of health services. To revitalize the health services, the Ministry of Health (MOH) first focused on improving their immunization services, including the immunization component of the Health Management Information System (HMIS). Secondly, to increase immunization coverage, the MOH set as a priority the elimination of prescribing false contraindications to immunization. To accomplish both goals, the MOH updated the national immunization policies and established a more effective structure for managing immunization services. To support the MOH, the US Agency for International Development (USAID) Resources for Child Health (REACH) and Basic Support for Institutionalizing Child Survival (BASICS) projects provided technical assistance through a resident coordinator and consultants, and by organizing an international seminar. The improvements extended beyond systems and forms, but, instead, emphasized monitoring by the frontline health worker and supervising the quality of health information. To accomplish their objectives, the MOH appointed a Working Group to define the problems, revise record-keeping procedures, and develop monitoring tools. This group, representing both national and local levels, was composed of MOH epidemiologists, paediatricians and a management information specialist. To reduce the burden of excessive record-keeping and reporting requirements, the Working Group identified four key indicators for the service delivery level: (1) DPT3 immunization coverage rates for children less than 1 year of age; (2) contraindication rates for DPT; (3) usage of DPT vaccine; and (4) daily refrigerator temperatures. Additional indicators were included at district and provincial levels. After a successful 1-year trial, the MOH implemented the revised HMIS nationally. Not only did the quality of the information system improve, but the new approach provided visible evidence, from facility to national levels, that the MOH was approaching their objective of reducing contraindication rates for DPT immunizations to 5% or less, and that vaccine wastage could be substantially reduced. The project demonstrated that giving health workers the basic epidemiologic skills to monitor their own work measurably improved the quality of the data, and by acquiring the new skills, the workers developed a sense of pride in their work.

Vaginal infections in pregnant women in Jamaica: prevalence and risk factors

Trichomoniasis, bacterial vaginosis (BV) and candidiasis are reproductive tract infections (RTIs) of the vagina. We conducted a cross-sectional study in 4 prenatal clinics in Kingston, Jamaica, to estimate the prevalence of these infections and the risk factors that may facilitate their transmission among pregnant women. Of the 269 women studied, 18.0% had culture-positive trichomoniasis, 44.1% had BV (Nugent score > or = 7) and 30.7% were positive for candidiasis by wet mount. A multiple logistic regression analysis showed that having a malodorous discharge was associated with trichomoniasis (odd ratios [OR]=3.9, confidence intervals [CI]=1.04-14.7) and BV (OR=3.4, CI=1.3-8.7). Women who took action to prevent HIV infection had lower BV prevalence (OR=0.34, CI=0.12-0.98). Women who were employed were less likely to have any of the infections (OR=0.61, CI=0.36-1.03). The strong association of a symptomatic presentation with trichomoniasis and BV suggests the merit of considering syndromic management of vaginitis in this population.

Geographical patterns of cholera in Mexico, 1991-1996

BACKGROUND

The seventh cholera pandemic has been ongoing in Mexico since 1991 and threatens to become endemic. This paper aims to determine the geographical pattern of cholera in Mexico to define areas at high risk of endemic cholera.

METHODS

Ecologic research was conducted based upon the cartography of disease incidence. The 32 Mexican states were grouped into five strata according to the value of the 1991-1996 cumulative incidence rate of cholera. Rate ratios were computed for strata of states classified by geographical situation, urbanization, and poverty level.

RESULTS

Cholera incidence was 2.47 times higher in coastal states than in the interior (95% CI : 2.42-2.52). The disease was negatively associated with urbanization. Incidence in the least urbanized stratum was four times as high as in the most urban stratum (95% CI : 3.9-4.12). The poorest stratum showed the most remarkable incidence, i.e. 5.9 times higher than the rate in the least poor stratum (95% CI : 5.73-6.04).

CONCLUSIONS

This ecologic research suggests that high poverty level, low urbanization, and southern location are the most important predictors of endemic cholera in Mexican states. It is hypothesized that the natural environment of the coastal plains in southern states may also play a significant role in cholera incidence. Poor communities residing in the southern, predominantly rural, coastal states should be prioritized when it comes to investing in safe water supply facilities, adequate excreta disposal systems and cholera surveillance.

John Snow: the first hired gun?

The 1854 English cholera outbreak led to reform of Victorian public health legislation, including the Nuisances Removal and Diseases Prevention Act. The reforms threatened the closure of many factories whose fumes were considered hazardous to the public's health. The second witness to appear before the Parliamentary committee considering the reforms was Dr. John Snow. Snow testified on behalf of the manufacturers threatened by the reforms. He stated that the fumes from such establishments were not hazardous. He contended that the workers in these factories did not become ill as a result of their exposures, and therefore these fumes could not be a hazard to the general public's health. Snow also presented data from the 1854 cholera outbreak as the basis for his belief that epidemic diseases were transmitted by water, not air. Although the data concerned cholera, Snow extended the inference to all epidemic diseases. When the committee's report was published, The Lancet chastised Snow in a stinging editorial. Parliament subsequently revised the bill in favor of the manufacturers and passed it into law. The implications of this particular episode in the history of epidemiology are discussed.

Amylase-resistant starch plus oral rehydration solution for cholera

BACKGROUND

Although standard glucose-based oral rehydration therapy corrects the dehydration caused by cholera, it does not reduce the diarrhea. Short-chain fatty acids, which are produced in the colon from nonabsorbed carbohydrates, enhance sodium absorption. We conducted a study to determine the effects of an orally administered, nonabsorbed starch (i.e., one resistant to digestion by amylase) on fecal fluid loss and the duration of diarrhea in patients with cholera.

METHODS

We randomly assigned 48 adolescents and adults with cholera to treatment with standard oral rehydration therapy (16 patients), standard therapy and 50 g of rice flour per liter of oral rehydration solution (16 patients), or standard therapy and 50 g of high-amylose maize starch, an amylase-resistant starch, per liter of oral rehydration solution (16 patients). The primary end points were fecal weight (for every 12-hour period during the first 48 hours after enrollment) and the length of time to the first formed stool.

RESULTS

The mean (+/-SD) fecal weights in the periods 12 to 24 hours, 24 to 36 hours, and 36 to 48 hours after enrollment were significantly lower in the resistant-starch group (2206+/-1158 g, 1810+/-1018 g, and 985+/-668 g) than in the standard-therapy group (3251+/-766 g, 2621+/-1149 g, and 2498+/-1080 g; P=0.01, P= 0.04, and P=0.001, respectively). From 36 to 48 hours after enrollment, fecal weight was also significantly lower with the resistant-starch therapy than with the rice-flour therapy (985+/-668 g vs. 1790+/-866 g, P=0.01). The mean duration of diarrhea was significantly shorter with the resistant-starch therapy (56.7+/-18.6 hours) than with standard therapy alone (90.9+/-29.8 hours, P=0.001) or the rice-flour therapy (70.8+/-20.2 hours, P=0.05). Fecal excretion of starch was higher with the resistant-starch therapy (32.6+/-30.4) than with the standard therapy (11.7+/-4.1 g, P=0.002) or the rice-flour therapy (15.1+/-8.4 g, P=0.01).

CONCLUSIONS

The addition of a resistant starch to oral rehydration solution reduces fecal fluid loss and shortens the duration of diarrhea in adolescents and adults with cholera.

Determination of drug susceptibility and DNA fingerprint patterns of clinical isolates of Mycobacterium tuberculosis from Kampala, Uganda

OBJECTIVE

To ascertain the rate of initial drug resistance and transmission patterns of Mycobacterium tuberculosis in Kampala, Uganda.

SETTING

National Tuberculosis (TB) Treatment Centre, Mulago Hospital, Kampala, Uganda and Case Western Reserve University, Cleveland, Ohio, USA and McClellan Memorial Veterans Hospital, Little Rock, Arkansas, USA.

METHODS

Using a radiometric BACTEC 460 TB system, susceptibility of 215 M. tuberculosis isolates from previously untreated patients from Kampala, Uganda (age range, 17-48 years, mean, 28 years; 56% males and 69% human immunodeficiency virus (HIV)-seropositive) was determined for isoniazid, rifampin, streptomycin and ethambutol. Isolates from 73 patients, selected on the basis of geographical location, were tested for strain diversity or relatedness using the IS6110 DNA fingerprinting technique.

RESULTS

Resistance rates were as follows: isoniazid, 7.9% streptomycin, 6.1% rifampin, 1.4% and ethambutol 0.9%. Twelve per cent of the strains were resistant to at least one of the first line drugs tested and 4.7% were multiply resistant. There were no significant differences in resistance rates between patients with and without HIV infection. Using the number and size of DNA fragments containing IS6110, only three clusters of isolates with identical RFLP patterns were found out of the 73 isolates tested (8.2%). Each cluster contained two isolates. Three (4.1%) isolates had less than seven copies of IS6110.

CONCLUSION

This study shows that in Uganda initial drug resistance rates to anti-tuberculosis agents are low and similar to other sub-Saharan African countries and that multiple strains of M. tuberculosis have been transmitted within the community.

Diphtheria in urban slums in north India

We recorded a reappearance of cases of microbiologically confirmed diphtheria in a tertiary care hospital in north India. Poor immunisation coverage, population migrations, and overcrowded urban slums may be contributory factors.

Elevated levels of maternal anti-tetanus toxin antibodies do not suppress the immune response to a Haemophilus influenzae type b polyribosylphosphate-tetanus toxoid conjugate vaccine

Reported are the effects of elevated levels of anti-tetanus antibodies on the safety and immune response to a Haemophilus influenzae type b polyribosylphosphate (PRP)-tetanus toxoid conjugate (PRP-T) vaccine. A group of Thai infants (n = 177) born to women immunized against tetanus during pregnancy were vaccinated with either a combined diphtheria-tetanus-pertussis (DTP) PRP-T vaccine or DTP and a PRP-conjugate vaccine using Neisseria meningitidis group B outer-membrane proteins as a carrier (PedVax HIB). Although most infants possessed high titres (> 1 IU/ml) of anti-tetanus antibodies, the DTP-PRP-T combined vaccine engendered an excellent antibody response to all vaccine components. In both vaccine groups > 98% of infants attained anti-PRP antibody titres > or = 0.15 microgram/ml. The geometric mean anti-PRP antibody titres were 5.41 micrograms/ml and 2.1 micrograms/ml for infants immunized with three doses of PRP-T versus two doses of PedVax HIB vaccines, respectively (P < 0.005). Similarly, the proportion of infants who achieved titres > or = 1 microgram/ml was higher in the PRP-T group (87.8%) than in the group immunized with PedVax HIB (74.2%) (P = 0.036). A subgroup analysis showed that there was no significant difference in the anti-PRP antibody response for infants exhibiting either < 1 IU of anti-tetanus antibody per millilitre or > or = 1 IU/ml at baseline. These finding indicate that pre-existing anti-carrier antibody does not diminish the immune response to the PRP moiety. All infants possessed protective levels of anti-D and anti-T antibody levels after immunization.

Neonatal tetanus associated with topical umbilical ghee: covert role of cow dung

BACKGROUND

Previous studies in Pakistan have shown that ghee (clarified butter) is commonly applied to umbilical wounds of neonates, and have documented that such applications are a risk factor for neonatal tetanus (NNT). In-use contamination of ghee with Clostridium tetani has been demonstrated, but mechanisms underlying the risk of ghee have been incompletely evaluated epidemiologically.

METHODS

Detailed information on ghee usage, including fuels used to heat it, was obtained from cases of NNT (n = 229) and their matched controls (n = 687) from a population-based study of NNT in Punjab Province, Pakistan. Design variables were created to evaluate the impact of different fuel sources on risk of ghee applications.

RESULTS

Nearly one-third of all infants had ghee applied, and it was nearly always heated before application to umbilical wounds of newborns. After controlling for all factors found to be significantly associated with NNT in conditional logistic regression, only ghee that had always been heated with dried cow dung fuel was significantly associated with NNT. Topical antimicrobials and ghee were never applied together.

CONCLUSIONS

Ghee applications to umbilical wounds, when heated with 'clean' fuels, appear to pose no increased risk of NNT, although handling practices undoubtedly result in hazardous microbial contamination. In contrast, ghee heated with dung fuel was significantly associated with NNT. The effective promotion of topical antimicrobials might help reduce ghee use, since the intended purpose of each is to enhance healing.

Rheumatic fever in children

Rheumatic fever (RF) and rheumatic heart disease (RHD) are major public health problems in developing countries. A prospective study carried out in a large general hospital showed that carditis was the predominant feature in first attack and also the recurrence of RF but that recurrence was associated with more severe manifestations. Echocardiography picked up cases of subclinical carditis. Presence of congestive cardiac failure in association with carditis always led to chronic RHD. Recurrence occurred only when patient defaulted penicillin prophylaxis. The overall recurrence rate was 0.026 per patient.

India embarks on vaccine-development scheme

Six diseases are the targets of the vaccine development program in India. The project involves 12 national research institutions and two private companies, Indian Immunologicals and Bharat Biotech, which are both based in Hyderabad, India. Targets of the program are AIDS, cholera, Japanese encephalitis, malaria, rabies, and tuberculosis. In a report in the journal Nature Medicine, K. S. Jayaraman notes that a single agency--the Department of Biotechnology (DBT)--will oversee the project. According to Jayaraman, DBT secretary Manju Sharma predicts the deployment of cholera and rabies vaccines by the year 2002. An oral recombinant cholera vaccine recently proved safe in Phase I trials at the Institute of Microbial Technology, Chandigart, and a promising DNA vaccine for rabies is in late preclinical development at the Indian Institute of Science, Bangalore. The AIDS vaccine initiative, underway at the All India Institute of Medical Sciences, New Delhi, will use a poxvirus construct expressing HIV-I subtype C, the strain most prevalent on the Indian subcontinent. N. K. Vinayak, head of the DBT medical division, told Jayaraman that the HIV vaccine would be ready for animal studies in a year. Funding for the program seems small by Western standards: $4 million over 3 years.