A large meteoritic event over Antarctica ca. 430 ka ago inferred from chondritic spherules from the Sør Rondane Mountains.

Large airbursts, the most frequent hazardous impact events, are estimated to occur orders of magnitude more frequently than crater-forming impacts. However, finding traces of these events is impeded by the difficulty of identifying them in the recent geological record. Here, we describe condensation spherules found on top of Walnumfjellet in the Sør Rondane Mountains, Antarctica. Affinities with similar spherules found in EPICA Dome C and Dome Fuji ice cores suggest that these particles were produced during a single-asteroid impact ca. 430 thousand years (ka) ago. The lack of a confirmed crater on the Antarctic ice sheet and geochemical and 18O-poor oxygen isotope signatures allow us to hypothesize that the impact particles result from a touchdown event, in which a projectile vapor jet interacts with the Antarctic ice sheet. Numerical models support a touchdown scenario. This study has implications for the identification and inventory of large cosmic events on Earth.

Seizures in the intrahippocampal kainic acid epilepsy model: characterization using long-term video-EEG monitoring in the rat.

OBJECTIVE: Intrahippocampal injection of kainic acid (KA) in rats evokes a status epilepticus (SE) and leads to spontaneous seizures. However to date, precise electroencephalographic (EEG) and clinical characterization of spontaneous seizures in this epilepsy model using long-term video-EEG monitoring has not been performed. MATERIALS AND METHODS: Rats were implanted with bipolar hippocampal depth electrodes and a cannula for the injection of KA (0.4 lg /0.2 ll) in the right hippocampus. Video-EEG monitoring was used to determine habitual parameters of spontaneous seizures such as seizure frequency, severity, progression and day-night rhythms. RESULTS: Spontaneous seizures were detected in all rats with 13 out of 15 animals displaying seizures during the first eight weeks after SE. A considerable fraction (35%) of the spontaneous seizures did not generalize secondarily. Seizure frequency was quite variable and the majority of the KA treated animals had less than one seizure per day. A circadian rhythm was observed in all rats that showed sufficient seizures per day. CONCLUSIONS: This study shows that the characteristics of spontaneous seizures in the intrahippocampal KA model display many similarities to other SE models and human temporal lobe epilepsy.

Prediction of recurrent disease by cytology and HPV testing after treatment of cervical intraepithelial neoplasia.

OBJECTIVE: To assess the role of human papillomavirus (HPV) testing and cytology as predictors of residual/recurrent disease after treatment of high-grade cervical intraepithelial lesions. METHODS: One hundred and thirty-eight women with cervical intraepithelial neoplasia (CIN) grade 2/3 lesion on biopsy were included in a prospective follow-up study in Belgium and Nicaragua. All women were treated with loop electrosurgical excision procedure (LEEP) and follow-up visits took place at 6 weeks, 6 months, 1 year and 2 years. During these visits, a Papanicolaou (Pap) smear test was taken, colposcopy was performed and specimens were collected for HPV testing. Cytology, high-risk (HR) HPV presence, persistent HR HPV infection and combinations of these tests at different time points during follow-up were correlated with histologically confirmed residual/recurrent disease. RESULTS: Thirteen patients (9%) developed residual/recurrent disease during follow-up. Abnormal cytology at 6 weeks after treatment was significantly correlated with residual/recurrent disease. Nine of thirty-seven patients with abnormal cytology at 6 weeks had recurrent disease versus three of seventy with a normal cytology [odds ratio (OR): 7.2; 95% confidence interval (CI): 1.8-28.5; P = 0.003). Sensitivity of this test was 75.0%, specificity 70.5%. Combining abnormal cytology and the presence of HR HPV within the first 6 months after treatment gave the best correlation with residual/recurrent disease: of the 54 women with abnormal cytology and/or HR HPV presence within the first 6 months, 11 developed residual/recurrent disease (OR 10.2; 95% CI: 2.2-48.3). Sensitivity of this combination was 84.6% and specificity 65.0%. CONCLUSION: Cytology remains the cornerstone in the early follow-up after LEEP for CIN lesions of the cervix. HPV testing can add value as it increases the sensitivity of cytology in concomitant testing within the first 6 months.

Natural history and clearance of HPV after treatment of precancerous cervical lesions.

AIM: To assess the clearance rate of human papillomavirus (HPV) after out-patient treatment of cervical intraepithelial neoplasia (CIN). METHODS AND RESULTS: A total of 122 Nicaraguan women with HPV DNA-positive and histologically confirmed CIN lesions were included in the study. Fifty-five patients with CIN1 and 67 with CIN2-3 were treated by cryotherapy and loop electrosurgical excision procedure (LEEP), respectively. Follow-up visits were scheduled at 6 weeks, 6 months, 1 year and 2 years. Investigations included cytology, HPV DNA testing and colposcopy/biopsy if needed. The clearance rate of HPV was calculated by multivariate logistic regression. Immediately after treatment, a pronounced decrease in presence of HPV was observed in both groups, with a significantly higher clearance in the LEEP group than in the cryotherapy group (P = 0.019). Subsequently, clearance continued over time and was similar between the cryotherapy group and the LEEP group (P = 0.73). Approximately the same detection rates were obtained for persistence of all HPV types and for high-risk types separately: 43.9, 37.6, 29.9 and 17.7% in the cryotherapy group and 24.9, 20.3, 15.3 and 8.4% in the LEEP group at 6 weeks, 6 months, 1 year and 2 years, respectively. CONCLUSIONS: Out-patient treatment of precancerous lesions of the cervix usually results in clearance of HPV. Both LEEP and cryotherapy are highly effective methods of eradicating HPV. HPV DNA testing may have added value in the follow-up of patients.

Prevalence of Sexually Transmitted Infections in Women Attending Antenatal Care in Tete Province; Mozambique

Objective. To determine the prevalence of Chlamydia trachomatis (CT); Neisseria gonorrhoeae (NG) and syphilis in pregnant women. Methods. A cross-sectional study was conducted among women attending antenatal care clinics (ANCs). Blood samples were tested for syphilis using the rapid plasma reagin (RPR) and treponemal haemaggluti- nation (TPHA) tests; CT and NG were diagnosed using a manual polymerase chain reaction assay on first-void urine samples. A socio-demographic questionnaire was completed. Results were compared with previous published data on sexually transmitted infection (STI) prevalence in Mozambique. Results. Blood and urine samples were collected from 1 119 and 835 women; respectively. The prevalence of CT was 4.1; and that of NG 2.5. The RPR test was positive in 5.2of the women; and 7.1had a positive TPHA test. Active syphiliswas found in 4.7. In univariate analysis; CT was associated with having had any level of education (p0.05); reactive RPR and TPHA were associated with illiteracy (p0.05); and TPHA was associated with age 25. Multivariate analysis did not show any significant association. In comparisonwith published data from 1993; a decline was observed for CT (p0.05); NG and syphilis (p0.001). Conclusions. Compared with available data; a decline of STI prevalence was observed in our setting. This might be the result of community-based education programmes focusing on changes to sexual behaviour; as well as the widespread use of the syndromic approach to managing STIs and the expansion of syphilis screening in primary health care settings. However; STI rates are still high; and the problem needs more concrete and sustained efforts for its control

Human papillomavirus and HPV vaccines: a review.

Cervical cancer, the most common cancer affecting women in developing countries, is caused by persistent infection with "high-risk" genotypes of human papillomaviruses (HPV). The most common oncogenic HPV genotypes are 16 and 18, causing approximately 70% of all cervical cancers. Types 6 and 11 do not contribute to the incidence of high-grade dysplasias (precancerous lesions) or cervical cancer, but do cause laryngeal papillomas and most genital warts. HPV is highly transmissible, with peak incidence soon after the onset of sexual activity. A quadrivalent (types 6, 11, 16 and 18) HPV vaccine has recently been licensed in several countries following the determination that it has an acceptable benefit/risk profile. In large phase III trials, the vaccine prevented 100% of moderate and severe precancerous cervical lesions associated with types 16 or 18 among women with no previous infection with these types. A bivalent (types 16 and 18) vaccine has also undergone extensive evaluation and been licensed in at least one country. Both vaccines are prepared from non-infectious, DNA-free virus-like particles produced by recombinant technology and combined with an adjuvant. With three doses administered, they induce high levels of serum antibodies in virtually all vaccinated individuals. In women who have no evidence of past or current infection with the HPV genotypes in the vaccine, both vaccines show > 90% protection against persistent HPV infection for up to 5 years after vaccination, which is the longest reported follow-up so far. Vaccinating at an age before females are exposed to HPV would have the greatest impact. Since HPV vaccines do not eliminate the risk of cervical cancer, cervical screening will still be required to minimize cancer incidence. Tiered pricing for HPV vaccines, innovative financing mechanisms and multidisciplinary partnerships will be essential in order for the vaccines to reach populations in greatest need.

Sexual behaviour and contraceptive use among youth in the Balkans.

OBJECTIVES: To assess sexual and health seeking behaviour related to contraception among high school students in Bosnia (Sarajevo), the FYR of Macedonia (Skopje), and Serbia and Montenegro (Belgrade and Podgorica). METHODS: A standardized questionnaire was self-administered by 2150 urban high school students. Multiple logistic regression analyses accounting for within-class correlation were applied to identify determinants of sexual behaviour, and the use of contraception and sexual and reproductive health (SRH) care. RESULTS: In this group of youth with a mean age of 16.7 years, 41.3% of the boys and 20.8% of the girls had already experienced sexual intercourse. Mean age at sexual debut differed between sexually active boys (15.5) and girls (16.3). A condom was used at first sex by 73.7% of the boys and by 69.0% of the girls. Condoms were consistently used during sexual intercourse with the current or last partner by 64.3% of the boys and 48.5% of the girls. Oral contraception was resorted to by 0.0% (Macedonia) to 10.6% (Bosnia) of sexually active girls. One third of sexually active girls and 18.0% of sexually active boys had ever refrained from seeking medical advice on SRH despite feeling the need for it, mainly because of feelings of shame, fear and insecurity. TV or radio and friends were mostly mentioned as useful sources of information on contraceptives. CONCLUSIONS: Age at sexual debut and the proportion of sexually active youth in these Balkan states do not differ from those in other parts of Europe. However, declining condom use after sexual initiation is not compensated by having recourse to other contraceptive methods, as seen in some West-European countries. The role of mass media in dissemination of information and tackling barriers to SRH care should be explored.

Prevalence of high risk human papillomavirus types among Nicaraguan women with histological proved pre-neoplastic and neoplastic lesions of the cervix.

OBJECTIVES: To determine the prevalence of high risk human papillomavirus (HPV) types in Nicaraguan women with histological proved pre-neoplastic and neoplastic cervical lesions, and to assess its potential impact on preventive strategies. METHODS: 206 women with histopathological confirmed cervical lesions (CIN I or worse) were screened for HPV DNA on a liquid based cytology sample, using an HPV short fragment polymerase chain reaction based assay. HPV positive samples were genotyped with a reverse hybridisation line probe assay (Lipa). HPV negative samples were re-analysed using type specific real time polymerase chain reaction. RESULTS: Of all lesions CIN II or worse, 12% tested negative. Prevalence of high risk HPV increased from 48.1% in cervical intraepithelial neoplasia I (CIN I) to 94.7% in invasive squamous cervical carcinoma (SCC). The most prevalent high risk HPV types were, in order of prevalence rate, HPV 16, 58, 31 and 52. HPV 16 and/or HPV 31 were present in 63.2% of SCC cases. CONCLUSION: Targeting HPV 16 and 31 with prophylactic vaccines could possibly have an important impact on the incidence of invasive cervical carcinoma in Nicaragua. Further research is needed to define the oncogenic potential of other high prevalent HPV genotypes. Meanwhile, primary prevention and cervical cancer screening programmes should be optimised.

Human papillomavirus DNA detection in women with primary abnormal cytology of the cervix: prevalence and distribution of HPV genotypes.

OBJECTIVES: In this study, we focus on the prevalence and occurrence of different anogenital human papillomavirus (HPV) genotypes in a first abnormal cervical screening test, and correlate HPV genotyping with the cytological diagnosis on thin-layer liquid-based preparations in routine gynaecological screening. METHODS: Out of 780 abnormal smears, 513 tested positive for HPV. All 25 different HPV types were identified by Line Probe Assay. RESULTS: The prevalence of high-risk HPV types increased from 72% in atypical squamous cell of undetermined significance to 94.5% in high-grade intra-epithelial lesion (HSIL). Co-infection with multiple HPV types was predominantly found in HSIL (35.8%). In the HSIL group the most common HPV types were 16, 52, 51 and 31; type 18 was rarely present. CONCLUSION: The role of types 31, 51 and 52 should be considered in future studies on vaccine development.

Comparison of pap smear, visual inspection with acetic acid, human papillomavirus DNA-PCR testing and cervicography.

OBJECTIVE: To assess the test qualities of four screening methods to detect cervical intra-epithelial neoplasia in an urban African setting. METHOD: Six hundred fifty-three women, attending a family planning clinic in Nairobi (Kenya), underwent four concurrent screening methods: pap smear, visual inspection with acetic acid (VIA), PCR for high risk human papillomavirus (HR HPV) and cervicography. The presence of cervical intra-epithelial neoplasia (CIN) was verified by colposcopy or biopsy. RESULT: Sensitivity (for CIN2 or higher) and specificity (to exclude any CIN or cancer) were 83.3% (95% CI [73.6, 93.0]) and 94.6% (95% CI [92.6, 96.5]), respectively, for pap smear; 73.3% (95% CI [61.8, 84.9]) and 80.0% (95% CI [76.6, 83.4]) for VIA; 94.4% (95% CI [84.6, 98.8]) and 73.9% (95% CI [69.7, 78.2]) for HR HPV; and 72.3% (95% CI [59.1, 85.6]) and 93.2% (95% CI [90.8, 95.7]) for cervicography. CONCLUSION: The pap smear had the highest specificity (94.6%) and HPV testing the highest sensitivity (94.4%). The visual methods, VIA and cervicography, were similar and showed an accuracy in between the former two tests.

Anti-epileptogenesis research: the clinical relevance.

In recent years, different research lines have examined the epileptogenic process in order to understand the different stages in this process, and with the hope that early recognition and intervention could prevent chronic epilepsy in patients with epileptic seizures. In animals, acquired epilepsy is studied most commonly with kindling models, status epilepticus models and traumatic brain injury models. Molecular genetic studies substantially help to understand age-specific channel and receptor abnormalities. Major progress has been made in recent years and we are now waiting for the first large scale multi-center clinical trials that test the possible anti-epileptogenic properties of anti-epileptic drugs or other compounds in well defined patient groups. In clinical practice, a structured diagnostic work-up in all patients with recurrent seizures is a first and necessary step in the recognition of patients at risk for developing chronic and refractory epilepsy.

Performance of the acetic acid test when used in field conditions as a screening test for cervical cancer.

OBJECTIVE: To assess if visual inspection with acetic acid (VIA) is a useful alternative screening test for cervical cancer, when used in a resource-poor setting with an existing cytology-based screening programme. METHODS: Women living in Rivas district (Nicaragua), who attended the programme, were concurrently screened with VIA and Papanicolau (PAP) smear. Screening was performed by health providers who had received training in VIA and a refresher course in cytology. Women testing positive for either of the results were referred for colposcopy and biopsy when indicated. The performance of VIA was compared with PAP smear, calculating the relative true and false positive rate (RELTPR and RELFPR) and for a high threshold on biopsy (cervical intraepithelial neoplasia grade 2 or a higher grade). We determined the trade-off between both tests by calculating the ratio of extra false positives detected through extra true positives (EFP:ETP ratio). RESULTS: A total of 1076 patients were screened. Nearly 33% had a positive screening test. On biopsy, 7.6% had a low-grade intraepithelial lesion, 4.5% a high-grade intraepithelial lesion (HSIL) and 0.5% invasive cancer. The RELTPR (VIA to PAP) was 1.96, the RELFPR 5.02 and the EFP:ETP ratio 8.04. VIA detected twice as much HSIL and invasive cancers as the PAP smear. Yet, for every extra diagnosis, eight extra false positives had to be examined at the referral level. CONCLUSIONS: The VIA spectacularly increases the number of HSIL and invasive cancers detected. The high FPR is a concern for the organization of the referral level. There is a need to establish uniform criteria on test positivity and to further improve the performance in field conditions.

Integration of cervical screening in family planning clinics.

OBJECTIVES: To assess the suitability of cervical cancer screening in family planning (FP) clinics and the relevance for women's health. METHODS: A survey was done on clients visiting the clinics of the Family Planning Association of Kenya (FPAK). Client characteristics, age, screening status and PAP smear results were registered. In-depth interviews were held with a limited number of staff and clients. RESULTS: In 1999, 38052 clients visited FPAK clinics, 43.5% were younger than 30 years old. More than 10000 cervical smears were taken. A total of 4.5% of the smears were abnormal, including 1.5% high-grade squamous intraepithelial lesions (HSIL) and 0.2% invasive cancers. The clinics were well prepared to provide high quality screening services. Patients and staff had a positive view on screening. CONCLUSIONS: Providing cervical cancer screening in FP clinics is beneficial for the clients but is unlikely to have an impact on the epidemiology of cervical cancer morbidity as FP services reach only a small percentage of the women who are most at risk. Measures to reach more and older women could assure a larger impact.

Determinants of cervical cancer screening in a poor area: results of a population-based survey in Rivas, Nicaragua.

OBJECTIVE: To obtain baseline information for designing a community-based intervention programme aimed at increasing the cervical cancer screening coverage of women most at risk. METHODS: A population-based survey, using proportional stratified two-stage cluster sampling in Rivas, one of the 16 Departments of Nicaragua. The individuals selected were interviewed at home by one of 26 interviewers, using a structured questionnaire. The questionnaire was designed to elicit (1) knowledge, attitudes and practices concerning sexual and reproductive health and behaviour, (2) risk factors for cervical cancer and (3) the use of health and cervical cancer screening services. RESULTS: A total of 612 men and 634 women participated in the survey. Of the women who had been sexually active at least 3 years, only 41.1% had undergone screening within that period and were considered adequately screened. Correlates of inadequate screening status included low educational level, exclusive use of public health facilities and lack of knowledge about prevention and symptoms of cervical cancer. Negligence, absence of medical problems, fear, lack of knowledge and economic reasons were the main reasons given for not being screened. Reluctance to be screened in the future was related to lack of knowledge of the disease, inadequate screening status, older age and low educational level. CONCLUSIONS: The current screening programme is not effective in reaching the majority of the population. Complementary activities such as education and information, as well as a more pro-active approach to invite women for screening are necessary.

Prevalence and risk factors of sexually transmitted infections and cervical neoplasia in women's health clinics in Nicaragua.

OBJECTIVES: To determine prevalence and risk factors of sexually transmitted infections (STIs), HIV, and cervical neoplasia in women attending women's health clinics in Nicaragua, and to assess the potential impact of screening for these diseases. METHODS: Consecutive women attending women's health clinics in different regions were interviewed and examined for STI, HIV, and cervical neoplasia. RESULTS: Whereas only 30.4% of the 1185 participating women attended the clinics because of STI related complaints, 77.0% reported symptoms after probing. Clinical cervicitis was diagnosed in 32.8%, Chlamydia trachomatis in 4.1%, gonorrhoea in 0.4%, trichomoniasis in 10.2%. Antibodies for syphilis were found in 0.7%, for hepatitis B in 3.7%, and none were HIV seropositive. The STI prevalence was 21.8% in women offending with complaints, 17.3% in symptomatic women after probing, and 14.8% in asymptomatic women. Abnormal Papanicolaou (Pap) smears were found in 7.7%, with high risk human papilloma virus (HPV) types in almost 60%. Male promiscuity was associated with high grade squamous intraepithelial lesions (HSIL) and reported former screening was not shown to be protective. Young age and being employed were risk factors for C. trachomatis. CONCLUSION: Nearly one out of five women attending women's health clinics in Nicaragua had an STI, and one out of 13 a precancerous lesion of the cervix. These clinics provide an opportunity to improve the reproductive health of women by probing for STI symptoms, especially in young women, and by offering cervical screening to casual attendees. Of concern is the high rate of cervical lesions in women with a screening history, underlining the need for proper quality control.

Sexually transmitted infections and reproductive health in Azerbaijan.

BACKGROUND: Little is known about the prevalence of sexually transmitted infections (STIs) and about sexual and reproductive health in Central and Eastern Europe. However, it is clear that major epidemics of STIs currently exist. GOAL: To provide baseline information for the development of national guidelines on the management of STIs in Azerbaijan. STUDY DESIGN: A prevalence study on STIs, including a questionnaire on sexual and reproductive health, in two regions of Azerbaijan targeted three groups: (1) pregnant women, (2) gynecology patients, and (3) men attending a dermatovenereology clinic. RESULTS: The 407 pregnant women in this study had a mean of 1.47 abortions and 1.40 births per woman. Of these women, 12% reported condom use and 41% previous symptoms of a sexually transmitted infection. Active syphilis was found in 1.7% of the women. The 326 gynecology patients had a mean of 2.54 abortions and 2.63 births per woman. Of these patients, 11% reported use of modern contraceptives, 18.3% previous condom use, and 63% previous symptoms of an STI. The prevalence of active syphilis was 2.2%, Chlamydia trachomatis 3.1%, Neisseria gonorrhoeae 2.8%, Trichomonas vaginalis 7.1%, Candida 33.1%, and bacterial vaginosis 32.5%. Of the 197 male patients, 67% reported multiple partners in the past 3 months, 62% money exchanged for sex, 37% condom use ever, and 40% a history of STIs. Active syphilis was found in 9.5% of the men, C trachomatis in 5.9%, N gonorrhoeae in 17%, and T vaginalis in 4.4%. CONCLUSIONS: The data show high-risk behavior in the men attending STI clinics, poor sexual and reproductive health status in the women, and underreporting of official data.

Syphilis control during pregnancy: effectiveness and sustainability of a decentralized program.

OBJECTIVES: This study sought to assess the performance, effectiveness, and costs of a decentralized antenatal syphilis screening program in Nairobi, Kenya. METHODS: Health clinic data, quality control data, and costs were analyzed. RESULTS: The rapid plasma reagin (RPR) seroprevalence was 3.4%. In terms of screening, treatment, and partner notification, the program's performance was adequate. The program's effectiveness was problematic because of false-negative and false-positive RPR results. The cost per averted case was calculated to be US$95 to US$112. CONCLUSIONS: The sustainability of this labor-intensive program is threatened by costs and logistic constraints. Alternative strategies, such as the mass epidemiologic treatment of pregnant women in high-prevalence areas, should be considered.

Vaginal lavage with chlorhexidine during labour to reduce mother-to-child HIV transmission: clinical trial in Mombasa, Kenya.

OBJECTIVES: To evaluate the effect of vaginal lavage with diluted chlorhexidine on mother-to child transmission of HIV (MTCT) in a breastfeeding population. METHODS: This prospective clinical trial was conducted in a governmental hospital in Mombasa, Kenya. On alternating weeks, women were allocated to non-intervention or to intervention consisting of vaginal lavage with 120 ml 0.2% chlorhexidine, later increased to 0.4%, repeated every 3 h from admission to delivery. Infants were tested for HIV by DNA polymerase chain reaction within 48 h and at 6 and 14 weeks of life. RESULTS: Enrolment and follow-up data were available for 297 and 309 HIV-positive women, respectively, in the non-lavage and the lavage groups. There was no evidence of a difference in intrapartum MTCT (17.2 versus 15.9%, OR 0.9, 95% CI 0.6-1.4) between the groups. Lavage solely before rupture of the membranes tended towards lower MTCT with chlorhexidine 0.2% (OR 0.6, 95% CI 0.3-1.1), and even more with chlorhexidine 0.4% (OR 0.1, 95% CI 0.0-0.9). CONCLUSION: The need remains for interventions reducing MTCT without HIV testing, often unavailable in countries with a high prevalence of HIV. Vaginal lavage with diluted chlorhexidine during delivery did not show a global effect on MTCT in our study. However, the data suggest that lavage before the membranes are ruptured might be associated with a reduction of MTCT, especially with higher concentrations of chlorhexidine.

Correlation between maternal and infant HIV infection and low birth weight: a study in Mombasa, Kenya.

This article aimed to examine the association between maternal and infant HIV infection and low birth weight (LBW <2500 grams). Data from 8563 singleton liveborns in Mombasa, Kenya, were analysed. Maternal HIV infection was found in 14.1% of the women and 9.6% of neonates had a birth weight of <2500 grams. In multivariate analysis, maternal HIV infection was independently associated with LBW (RR=1.46, 95% CI=1.20-1.79, P =0.0002). Maternal age, primiparity, sex of the baby, religion, syphilis infection, anaemia and previous history of stillbirth were also independently associated with LBW (RR: 1.32, 2.19, 1.44, 1.56, 1.61, 1.31 and 1.69, respectively). The rate of intra-uterine HIV transmission was 5.1% and 20.1% of the exposed infants were infected during the intrapartum period. Intrapartum infected infants had a relative risk of LBW of 1.95 (95% CI=1.18-2.87, P <0.01) compared to uninfected children, whereas the birth weight of infants infected in utero was not different from uninfected infants (RR=1.18, 95% CI=0.56-2.60, P=0.630). HIV infected mothers are more likely to have small babies, even after controlling for possible confounding factors. Low birth weight babies were more at risk for peripartum HIV transmission, but further research is needed to study mechanisms of transmission in relation to birth weight.