Transplacental transmission of Wuchereria bancrofti in Haitian women.

To document the occurrence of transplacental transmission of microfilariae and to determine how frequently it occurred, umbilical cord blood samples and placental tissues were collected from 22 microfilaria-positive women in an area with endemic Wuchereria bancrofti. Microfilaria (mf) counts in the women ranged from 1 to 3,820 mf/ml. Microfilariae were detected in 2 placenta samples and a single cord blood sample. The positive cord blood sample and 1 of the positive placenta samples came from the same woman; no microfilariae were found in a finger prick sample taken from the infant 3 wk after delivery. Our results suggest that microfilariae cross the placenta in less than 10% of pregnancies of microfilaria-positive mothers. Furthermore, the microfilaria count of the mother does not seem to influence directly whether microfilariae are present in the placental blood pool. Although actual transfer of microfilariae to the fetus may occur infrequently, exposure to parasite antigens occurs with much greater frequency. The effect of in utero exposure to either microfilariae or parasite antigens may render newborns tolerant and explain why children born to infected mothers are almost 3 times more likely to become infected than are children born to uninfected women.

Comparison of high dose ivermectin and diethylcarbamazine for activity against bancroftian filariasis in Haiti.

This three-phase study was designed to compare high dose ivermectin with a standard diethylcarbamazine (DEC) regimen for patient tolerability, potential to kill adult filaria, and duration of microfilarial suppression in 30 Haitian subjects with Wuchereria bancrofti microfilaremia. All were first given a 1-mg oral dose of ivermectin (phase 1) to reduce microfilaria densities. Participants were randomized into three groups: Group 1 received DEC (6mg/kg per day for 12 days), Group 2 received 200 mcg/kg of ivermectin, and Group 3 received 400 mcg/kg of ivermectin (200 mcg/kg per day for 2 days). All drug regimens were well tolerated with few adverse reactions. Most reactions occurred during phase I and consisted primarily of headache, fever, and myalgia. At the end of phase 1, 27 of 30 (90%) patients were microfilaria negative. During phase 2, four of the six men receiving DEC developed scrotal reactions suggesting killing adult worms; no such reactions were noted in 10 men receiving ivermectin (p less than 0.05). At one-year follow up (phase 3), all treatment groups had less than 10% return to pretreatment microfilaria levels. The mean percent of baseline microfilaria counts were for Group 1, 0.9% (range 0-5%); Group 2, 8.2% (range 0-31%); and Group 3, 3.8% (range 0-25%). Seven individuals in Group 1 were microfilaria-negative, while only one and three individuals were microfilaria-negative in Groups 2 and 3, respectively. These results suggest that DEC causes more damage to the adult worms and greater reduction in microfilaria densities than ivermectin, but that high doses of ivermectin may suppress microfilaremia in lymphatic filariasis for periods much longer than previously reported.

Clinical evaluation of Mansonella ozzardi in Haiti.

The clinical evaluation of 150 individuals in Bayeux, Haiti, revealed no significant morbidity that could be attributed to infection with Mansonella ozzardi. However, the distribution of patent infections and their microfilaria density were significantly affected by the age and sex of the individuals. Also, the eosinophilic response was associated with the intensity of the microfilaremia when age was considered as a co-variable. The microfilaria rate was significantly higher in certain occupations, but this was discounted as a risk factor for reasons that are explained.

A cooperative model for provision of regional health services in a developing nation.

The development of health care in the Leogane region of Haiti has been a ten-year story of international cooperation among health professionals, of closely targeted assistance, and of policy coordination between assisting private agencies and the Haitian government. The broadly based health care program of l'Hopital Sainte Croix of Leogane is presented as a model of a cooperative effort that has resulted in rapid regional health care development and as an encouragement to the many differing types of groups responding to a world in medical need.

[Absence of response of Mansonella ozzardi microfilaria in the diethylcarbamazine provocation test]. / Défaut de réponse des microfilaires Mansonella ozzardi au test de provocation par le diéthyl-carbamazine.

One hundred and twelve inhabitants of an area endemic for M. ozzardi received 20 cmm capillary blood samples by finger prick before and 30 minutes after the ingestion of 100 mg of diethylcarbamazine citrate. No significant variations in microfilaremia were detected. Thus, a provocative dose of DEC would not appear to be helpful in sampling for mansonellosis in Haiti.

Mansonella ozzardi in Haiti. I. Epidemiological survey.

A survey of 1,165 inhabitants of Bayeux, Haiti revealed that 16% were infected with Mansonella ozzardi. This was determined from a single 20 mm3 sample of finger prick blood from each individual. Amont children and young adults (< 20 years of age), fewer than 2% had detectable microfilaremias. Beyond this age the prevalence of infection for males and females was 49% and 24%, respectively. The microfilariae circulate in the peripheral blood with no significant periodicity. In general, the microfilaremias were low, with 71% of the positive cases having less than 10 microfilariae in 20 mm3 of blood; only 4% had more than 50 microfilariae. Histological examination of sectioned skin biopsies showed that the microfilariae dwell within the superficial capillary vessels; not free in the extravascular tissues.